Ametek 888 User Manual

PN 883056901 REV. F

Model 888 Tail Gas Analyzer

ATEX/IECEx

User Manual

Process Instruments

Western Research

455 Corporate Boulevard

Newark, DE 19702

USA

- Delaware

455 Corporate Blvd., Newark DE 19702

OFFICES

USA

- Pennsylvania

150 Freeport Road, Pittsburgh PA 15238

CANADA

- Alberta

2876 Sunridge Way N.E., Calgary, AB T1Y 7H9

Tel: 302-456-4400

Fax: 302-456-4444

Tel: 412-828-9040

Fax: 412-826-0399

Tel: +1-403-235-8400

Fax: +1-403-248-3550

WORLDWIDE SALES AND SERVICE LOCATIONS

USA

- Texas

Tel: 713-466-4900, Fax: 713-849-1924

CHINA

Beijing / Tel: 86 10 8526 2111, Fax: 86 10 8526 2141

Chengdu / Tel: 86 28 8675 8111, Fax: 86 28 8675 8141

Shanghai / Tel: 86 21 6426 8111, Fax: 86 21 6426 7818

FRANCE

Tel: 33 1 30 68 89 20, Fax: 33 1 30 68 89 29

GERMANY

Tel: 49 21 59 91 36 0, Fax: 49 21 59 91 3639

MIDDLE EAST

- Dubai

Tel: 971 4 881 2052, Fax: 971 4 881 2053

SINGAPORE

Tel: 65 6484 2388, Fax: 65 6481 6588 www.ametekpi.com

© 2014 AMETEK Process & Analytical Instruments Division

This document contains Essential Health and Safety information for the use of the AMETEK Model 888 ATEX Tail Gas Analyzer. Data herein has been verified and validated and is believed adequate for the intended use of this instrument. If the instrument or procedures are used for purposes over and above the capabilities specified herein, confirmation of their validity and suitability should be obtained; otherwise, AMETEK does not guarantee results and assumes no obligation or liability. This publication is not a license to operate under, or a recommendation to infringe upon, any process patents.

2 | Model 888 ATEX/IECEx Tail Gas Analyzer

Contents

About This Document ............................................................................................7

Safety Notes ..........................................................................................................7

Important Safety Information .................................................................................8

Warning Labels ....................................................................................................10

Protective Conductor Terminal ............................................................................10

Environmental Information (WEEE) .....................................................................10

Electromagnetic Compatibility (EMC) .................................................................. 11

Classified, Hazardous Area Protection ...............................................................13

Components and Functions ..........................................................................13

Warranty and Claims ...........................................................................................15

CHAPTER 1 Overview

Model 888 Tail Gas Analyzer ..............................................................................1-1

Electronics Enclosure...................................................................................1-2

Photometer...................................................................................................1-2

Xenon Lamp Assembly ................................................................................1-3

Detector Assembly .......................................................................................1-3

Lamp & Detector Mounting ..........................................................................1-4

User Interface/Host Display .........................................................................1-4

Sensor Board ...............................................................................................1-4

Sample Conditioning (Oven) Enclosure .......................................................1-4

Light Tube/Mirror Block Assembly ................................................................1-5

Demister .......................................................................................................1-6

Sample Cell ..................................................................................................1-6

Steam Blowback Valve .................................................................................1-7

Heat Exchangers..........................................................................................1-7

Customer Connections.................................................................................1-8

Customer Drawing Package ......................................................................1-10

Operation .......................................................................................................... 1-11

Timing Sequence ....................................................................................... 1-11

Sample Flow ..............................................................................................1-12

CHAPTER 2 Specifications

Model 888 Tail Gas Analyzer ..............................................................................2-1

CHAPTER 3 Installation and Start-Up

Prior to Installation ..............................................................................................3-1

Personnel Technical Level Required for Installation ....................................3-1

Analyzer Site Preparation ............................................................................3-2

Unpacking and Inspection ............................................................................3-2

Space Requirements....................................................................................3-2

Installation Guidelines ........................................................................................3-5

Sample Tap Preparation ...............................................................................3-6

Installation Procedure .........................................................................................3-8

Contents | 3

Installing the Probe .............................................................................................3-9

Installing the Demister ......................................................................................3-13

Purge Installation .......................................................................................3-15

Electrical Connections ...............................................................................3-16

System Start-Up and Operation .......................................................................3-18

Leak Checking ...........................................................................................3-18

Leak Checking (without power) ...........................................................3-18

Purging the Electronic Enclosure ...............................................................3-18

Adjusting the Purge Controller .............................................................3-20

System Operation .............................................................................................3-21

Analyzer Security - Passwords ..................................................................3-21

Starting Normal Operation .........................................................................3-22

Setting the Sample Gas Flow ..............................................................3-23

Analyzer Timing ..........................................................................................3-25

Normal Timing Sequence ....................................................................3-27

Calibration Span Adjustment ............................................................................3-29

Calibration Procedure ................................................................................3-30

Analyzer Troubleshooting and Maintenance ....................................................3-33

Cleaning/Replacing Parts in the Sampling System ...................................3-33

Other Maintenance.....................................................................................3-34

Sample System Leakage Test ....................................................................3-34

CHAPTER 4 Controller / User Interface

Refer to 883056904 User Interface Manual for details on the AMEVision interface. ...............................................................................................4-1

CHAPTER 5 Alarms

Alarm Relays ......................................................................................................5-1

System Alarm - Relay 1 ................................................................................5-1

Data Valid Alarm - Relay 2 ...........................................................................5-1

Programmable Relays - Relay 3 and Relay 4 ..............................................5-1

Alarm Conditions and Responses ......................................................................5-2

CHAPTER 6 Troubleshooting

Diagnostic Functions ..........................................................................................6-1

Diagnostics Mode.........................................................................................6-1

Problems and Possible Causes ..........................................................................6-2

Oven/Cell Temperature Not Reaching Setpoint ...........................................6-2

Demister Temperature Not Reaching Setpoint .............................................6-2

Low Light Conditions ....................................................................................6-3

Cleaning the Optical Surface .................................................................6-4

Check the Optical Alignment .................................................................6-5

CHAPTER 7 Parts Replacement

Part Numbers ....................................................................................................7-3


APPENDIX A Wiring Diagrams

APPENDIX B H

2

S and SO

2

Calculations

Concentration Measurement ............................................................................. B-1

Absorbance Calculation .............................................................................. B-1

Excess H

2

S, Excess SO

2

, Ratio (H

2

S/SO

2

) and Total (H

2

S + SO

2

) ...... B-2

Air Demand .......................................................................................... B-2

APPENDIX C Analyzer Timing

Timing States / Periods ...................................................................................... C-1

Period 1 – Special Flush ............................................................................. C-1

Period 2 – Flush and Zero........................................................................... C-1

Period 3 – Sample Flush ............................................................................. C-2

Period 4 – Measure ..................................................................................... C-2

Zero and Photo-Span Calibration ......................................................... C-2

Operation Sequences ........................................................................... C-3

Period 5 – Flush and Zero........................................................................... C-3

Period 6 – Track Zero.................................................................................. C-3

Period 7– Photo-Span Calibration............................................................... C-3

Period 8 – Track Photo-Span Calibration .................................................... C-4

Steam Blowback ................................................................................... C-4

Period 9 – Pre-Steam Flush ........................................................................ C-4

Period 10 – Steam Blowback ...................................................................... C-4

Period 11 – Post Steam Flush ..................................................................... C-4

Special Periods .................................................................................................. C-5

Period 12 – Continuous Flush ..................................................................... C-5

Period 13– Continuous Hold ....................................................................... C-5

Period 14 – Continuous Sample ................................................................. C-5

APPENDIX D Parameter IDs / Modbus Addresses

APPENDIX E Alarm Codes

Contents | 5


About This Document

This document describes the user instructions for the safe operation of the

Model 888 Analyzer intended for use in explosive atmosphere locations

(Zone 1).

The procedures and information discussed in this document are the procedures to install, operate, and perform maintenance on the Model 888

Analyzer including all relevant safety warnings and cautions to ensure the safety of personnel and the analyzer in explosive atmosphere locations.

Safety Notes

Warnings, cautions, and notes contained in this document and in the User

Manual emphasize critical instructions as follows:

!

WARNING

An operating procedure which, if not strictly observed, may result in personal injury or environmental contamination.

!

CAUTION

An operating procedure which, if not strictly observed, may result in damage to the equipment.

Important information that should not be overlooked.

Contents | 7

Important Safety Information

Before working on the analyzer, read and understand the following

Notes, Warnings, and Cautions, regarding safety and other required information.

Additional Notes, Warnings, and Cautions included in individual procedures in this document (and in the analyzer User Manual) indicate special conditions to consider during installation, before opening the analyzer covers or doors, and while working on the analyzer.

High voltages are present in the analyzer housings. Always disconnect power and/or external power sources to the analyzer before opening any covers or doors on the analyzer to check or perform maintenance on any components within the enclosures.

!

WARNING

If it is necessary to open the analyzer’s covers or doors while the circuits are live, first monitor the area for flammable gases and proceed only when the area is safe.

When the Electronics Enclosure and/or other enclosures are open, take appropriate precautions to avoid electrical shock. Hazardous voltages are present inside.

!

WARNING

All electrical connections, adjustments, or servicing of the analyzer should be performed only by properly trained and qualified personnel.

All electrical connections, materials, and methods (plus all safety standards and procedures) must be made in compliance with local wiring regulations and electrical code for the hazardous area, as specified by the Owner Company, local electrical-inspection authority, and

National/EU regulations.

Follow appropriate regulatory and/or company procedures to lock out the analyzer while working on the analyzer electronics.

!

WARNING

Verify ground continuity of all equipment before applying power.

For electrical shock protection, the analyzer must be operated from a grounded power source that has a securely connected protective ground contact.


!

WARNING

WARNING

!

WARNING

!

!

WARNING

The glass Xenon Flash Lamp is under high internal pressure which could result in flying glass fragments if ruptured. Handle the tube with care to avoid dropping it, subjecting it to impacts, applying excessive force to it, or scratching it.

While handling a flash lamp, always wear protective devices (face mask, clothing) to prevent possible injury, especially to hand and face areas.

Before working on the sample system, confirm that the system has been purged with zero fluid and is isolated (blocked in) from the process.

The analyzer oven enclosure and components inside the analyzer oven are hot; always wear protective devices to avoid burning yourself.

Check the sample probe installation, sample connections at analyzer, and sample return for leaks before opening sample inlet ball valve and sample return valve.

The sample gas contains highly toxic and corrosive substances.

Proper personal protective equipment including fresh air breathing apparatus, eye protection, and skin protection MUST BE worn when installing the sample tap and/or opening the main oven chamber for inspection or maintenance.

The sample gas contains highly toxic and corrosive substances. Analyzed sample must be returned to the process or vented to a safe area.

!

WARNING

!

WARNING

THIS ENCLOSURE IS PROTECTED BY PURGING

Enclosure shall not be opened unless the area is known to be nonhazardous, or unless all devices within have been de-energized. Power shall not be restored after enclosure has been opened until the enclosure has been purged in accordance with the purge system start-up instructions.

ATTENTION

Humidity may damage the installed Optical Filters. Any such damage is not covered by Ametek’s warranty. Please consult Ametek or your local Ametek represenitive for further advise.

Contents | 9

Warning Labels

These symbols may appear on the instrument to alert you of existing conditions.

PROTECTIVE CONDUCTOR TERMINAL

(BORNIER DE L’ECRAN DE PROTECTION)

Schutzerde

!

CAUTION

CAUTION - Risk of electric shock

(ATTENTION-RISQUE DE DÉCHARGE ÉLECTRIQUE)

Achtung - Hochspannung Lebensgefahr

CAUTION - Refer to accompanying documents

(ATTENTION-SE RÉFERER AUX DOCUMENTS JOINTS)

Achtung (Beachten Sie beiliegende Dokumente)

CAUTION - Hot Surface

(ATTENTION-SURFACE CHAUDE)

Achtung - Heiße Oberfläche

Environmental Information (WEEE)

This AMETEK product contains materials that can be reclaimed and recycled. In some cases the product may contain materials known to be hazardous to the environment or human health. In order to prevent the release of harmful substances into the environment and to conserve our natural resources, AMETEK recommends that you arrange to recycle this product when it reaches its “end of life.”

Waste Electrical and Electronic Equipment (WEEE) should never be disposed of in a municipal waste system (residential trash). The Wheelie Bin marking on this product is a reminder to dispose the product properly after it has completed its useful life and been removed from service. Metals, plastics and other components are recyclable and you can do your part by one of the following these steps:

• When the equipment is ready to be disposed of, take it to your local or regional waste collection administration for recycling.

• In some cases, your “end-of-life” product may be traded in for credit towards the purchase of new AMETEK instruments. Contact your dealer to see if this program is available in your area.

• If you need further assistance in recycling your AMETEK product, contact our office listed in the front of the instruction manual.


Electromagnetic Compatibility (EMC)

!

CAUTION

Read and follow the recommendations in this section to avoid performance variations or damage to the internal circuits of this equipment when installed in harsh electrical environments.

The various configurations of the Model 888 should not produce, or fall victim to, elec tromagnetic disturbances as specified in the European Union’s EMC Directive. Strict compliance to the EMC Directive requires that certain installation techniques and wiring practices are used to prevent or minimize erratic behavior of the Analyzer or its electronic neighbors. Below are examples of the techniques and wiring practices to be followed.

In meeting the EMC requirements , the various Analyzer configurations described in this manual rely heavily on the use of metallic shielded cables used to connect to the custom er’s equipment and power. Foil and braid shielded I/O and DC power cables are recom mended for use in otherwise unprotected situations. In addition, hard conduit, flexible conduit, and armor around non-shielded wiring also provides excellent control of radio frequency disturbances. However, use of these shielding techniques is effective only when the shielding element is connected to the equipment chassis/earth ground at both ends of the cable run. This may cause ground loop problems in some cases. These should be treated on a case-by-case basis. Disconnecting one shield ground may not provide suf ficient protection depending on the electronic environment. Connecting one shield ground via a 0.1 microfarad ceramic capacitor is a technique allowing high frequency shield bonding while avoiding the AC-ground metal connection. In the case of shielded cables the drain wire or braid connection must be kept short. A two-inch connection distance between the shield’s end and the nearest grounded chassis point, ground bar or terminal is highly recommended. An even greater degree of shield performance can be achieved by using metallic glands for shielded cable entry into metal enclosures. Expose enough of the braid/foil/drain where it passes through the gland so that the shield materials can be wrapped backwards onto the cable jacket and captured inside the gland, and tightened up against the metal interior.

Inductive loads connected to the low voltage “Alarm Contacts” are not recommended.

However, if this becomes a necessity, adhere to proper techniques and wiring practices.

Install an appropriate transient voltage suppression device (low voltage MOV, “Tran szorb,” or R/C) as close as possible to the inductive device to reduce the generation of transients. Do not run this type of signal wiring along with other I/O or DC in the same shielded cable. Inductive load wiring must be separated from other circuits in conduit by using an additional cable shield on the offending cable.

In general, for optimum protection against high frequency transients and other distur bances, do not allow installation of this Analyzer where its unshielded I/O and DC cir cuits are physically mixed with AC mains or any other circuit that could induce transients into the Analyzer or the overall system. Examples of electrical events and devices known for the generation of harmful electromagnetic disturbances include motors, capacitor bank switching, storm related transients, RF welding equipment, static, and walkie-talk ies.

Contents | 11

Classified, Hazardous Area Protection

Components and Functions

The Zone 1 version of the Model 888 is designed to be, and comply with requirements for, electrical equipment in Zone 1 classified hazardous areas. The methods of protection used include type “p” (pressurized), and type “d” (flameproof enclosure). The purge system, redundant heater control, and enclosure designs assure that the system will not ignite surrounding gases. For this reason, any repairs must not bypass these safety considerations and must use only recommended components. The purge system consists of a regulated supply of instrument air, the electronics enclosure, purge enclosure and purge exhaust vent.

The purge controller monitors the enclosure pressure and interrupts mains power in the event pressure is lost. A disconnect assembly within a flameproof enclosure isolates all external signals should mains power be disconnected.

After the instrument air (or nitrogen) supply has been connected to the analyzer and turned on, the system is to be purged for approximately 10 minutes to ensure five (5) full exchanges of air within the purged enclosure. The flow is controlled by the purge controller through an exhaust vent. Once the controller senses that there have been five air exchanges within the enclosure, mains power is connected to the electronics.

When the electronics enclosure is opened or the pressurization gas supply is lost, the purge controller will disconnect mains power which, in turn, will disconnect all signal wiring. The analyzer should not be used without purge protection unless the area is known to be safe and is being continuously monitored (See Combustible Gas Detection protection techniques in

NFPA70 article 500 and 505).

The analyzer must be installed and operated in accordance with this instruction manual.

Working with the purged enclosure in an open position is typically done only during installation, start-up (and verification), and certain troubleshooting and maintenance procedures. In these cases, appropriate safety conditions must have been met, per company policy.

!

WARNING

The analyzer may only be energized with permission of the works manager or his proxy. Permission may only be given when it has been determined that an explosive atmosphere is not present or when the necessary protective measures against explosion hazards have been taken (“hot permit”) during the time that the system is energized.

The analyzer enclosure may not be opened when energized if an explosive atmosphere is present.

For normal analyzer operation, the purge system must on.

Warranty and Claims

We warrant that any equipment of our own manufacture or manufactured for us pursuant to our specifications which shall not be, at the time of shipment thereof by or for us, free from defects in material or workmanship under normal use and service, will be repaired or replaced (at our option) by us free of charge, provided that written notice of such defect is received by us within twelve (12) months from date of shipment of portable analyzers or within eighteen (18) months from date of shipment or twelve (12) months from date of installation of permanent equipment, whichever period is shorter. All equipment requiring repair or replacement under the warranty shall be returned to us at our factory, or at such other location as we may designate after obtaining a Returned Material Authorization (RMA) number, transportation prepaid. Such returned equipment shall be examined by us and if it is found to be defective as a result of defective materials or workmanship, it shall be repaired or replaced as aforesaid. Our obligation does not include the cost of furnishing any labor in connection with the installation of such repaired or replaced equipment or parts thereof, nor does it include the responsibility or cost of transportation. In addition, instead of repairing or replacing the equipment returned to us as aforesaid, we may, at our option, take back the defective equipment, and refund in full settlement the purchase price thereof paid by

Buyer.

Process photometric analyzers, process moisture analyzers, and sampling systems are warranted to perform the intended measurement, only in the event that the customer has supplied, and AM-

ETEK has accepted, valid sample stream composition data, process conditions, and electrical area classification prior to order acknowledgment. The photometric light sources are warranted for ninety (90) days from date of shipment. Resale items warranty is limited to the transferable portion of the original equipment manufacturer’s warranty to AMETEK. If you are returning equipment from outside the United State, a statement should appear on the documentation accompanying the equipment being returned declaring that the goods being returned for repair are American goods, the name of the firm who purchased the goods, and the shipment date.

The warranty shall not apply to any equipment (or part thereof) which has been tampered with or altered after leaving our control or which has been replaced by anyone except us, or which has been subject to misuse, neglect, abuse or improper use. Misuse or abuse of the equipment, or any part thereof, shall be construed to include, but shall not be limited to, damage by negligence, accident, fire or force of the elements. Improper use or misapplications shall be construed to include improper or inadequate protection against shock, vibration, high or low temperature, overpressure, excess voltage and the like, or operating the equipment with or in a corrosive, explosive or combustible medium, unless the equipment is specifically designed for such service, or exposure to any other service or environment of greater severity than that for which the equipment was designed.

The warranty does not apply to used or secondhand equipment nor extend to anyone other than the original purchaser from us.

THIS WARRANTY IS GIVEN AND ACCEPTED IN LIEU OF ALL OTHER WARRANTIES, WHETH-

ER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION AND WARRANTIES OF FIT-

NESS OR OF MERCHANTABILITY OTHER THAN AS EXPRESSLY SET FORTH HEREIN, AND

OF ALL OTHER OBLIGATIONS OR LIABILITIES ON OUR PART. IN NO EVENT SHALL WE BE

LIABLE UNDER THIS WARRANTY OR ANY OTHER PROVISION OF THIS AGREEMENT FOR

ANY ANTICIPATED OR LOST PROFITS, INCIDENTAL DAMAGES, CONSEQUENTIAL DAM-

AGES, TIME CHANGES OR ANY OTHER LOSSES INCURRED BY THE ORIGINAL PURCHASER

OR ANY THIRD PARTY IN CONNECTION WITH THE PURCHASE, INSTALLATION, REPAIR

OR OPERATION OF EQUIPMENT, OR ANY PART THEREOF COVERED BY THIS WARRANTY

OR OTHERWISE. WE MAKE NO WARRANTY, EXPRESS OR IMPLIED, INCLUDING WITHOUT

LIMITATION ANY WARRANTIES OF FITNESS OR OF MERCHANTABILITY, AS TO ANY OTHER

MANUFACTURER’S EQUIPMENT, WHETHER SOLD SEPARATELY OR IN CONJUNCTION

WITH EQUIPMENT OF OUR MANUFACTURE. WE DO NOT AUTHORIZE ANY REPRESEN-

TATIVE OR OTHER PERSON TO ASSUME FOR US ANY LIABILITY IN CONNECTION WITH

EQUIPMENT, OR ANY PART THEREOF, COVERED BY THIS WARRANTY.

OVERVIEW


The AMETEK Model 888 Tail Gas Analyzer uses photometric analysis to continuously monitor hydrogen sulfide, H ent in the tail gas stream of a Claus plant.

2

S, and sulfur dioxide, SO

2

, pres -

Electronics Enclosure

Purge Air Inlet

Oven Enclosure

Purge

Controller

Steam

Blowback

Inlet

(optional)

Utility

Port

Customer Connection

Enclosure

FRONT VIEW Model 888 Tail Gas Analyzer ATEX/IECEx

Figure 1-1. Model 888 ATEX Enclosures

SIDE VIEW

The analyzer consists of three enclosures (Figure 1-1): an electronics enclosure; a temperature-controlled, flange-mounted, sample conditioning enclosure; and a signal disconnect enclosure. These enclosures are assembled onto a rigid mounting panel for support and the full assembly is installed directly on a pipeline. The analyzer is designed for outdoor, hazardous area installations.

Overview | 1-1

B

4

4

3 2

Electronics Enclosure

SENSOR PCB ASSEMBLY

@ I

PURGE VENT

W

+

0

PURGE CONTROLLER

HOST DISPLAY PCB

DETECTOR ASSEMBLY

HOST DISPLAY BATTERY

AC/DC CONVERTER PCB

LINE FILTER

24 VOLT POWER SUPPLY t::ll

I . i ik I

PROPORTIONAL VALVE

FLASH LAMP POWER SUPPLY

FLASH LAMP

TEMPERATURE SIGNAL CONVERTER (SIL2)

PRESSURE TRANSDUCER

HEATER RELA Y

Figure 1-2. Electronics Enclosure - Zone 1

Photometer

This analyzer uses a photometer to monitor the concentration of H

SO

2

3 2

2

S and

in a tail gas sample. A photometer is composed four main components: (1) a source of EM radiation (or “light”) in the desired wavelength region; (2) a measuring cell with windows capable of transmitting light in the desired wavelength region and compatible with the sample composition; (3) a wavelength selection device to isolate the desired wavelength region; and (4) a detector (or sensor) that is sensitive to the wavelength region.

1-2 | Model 888 ATEX IECEx Tail Gas Analyzer

1

1

A

In this analyzer, the photometer spans from the electronics enclosure to sample conditioning enclosure. The electronics enclosure houses the source and detector assemblies. The sample conditioning enclosure houses the light tube, mirror-block, and sample cell assemblies. All of the photometer components are rigidly connected for optical stability.

Xenon Lamp Assembly

The source module consists of a high quality 3 mm arc xenon flash lamp,

0.1 uF close-coupled capacitor, and trigger electronics (with 50 Hz flash rate). The close-coupled capacitor and trigger electronics are potted inside a metal enclosure. The xenon lamp assembly is powered from the Xenon

Lamp Power Supply PCB.

Detector Assembly

Figure 1-3. Detector

The detector assembly consists of focusing optics, three beam splitters, one front surface mirror, four band pass filters for wavelength selection

(centered at 232, 254, 280, and 400 nm), four silicon photodiodes, and electronics. Upon exiting the sample cell, the light re-enters the electronics and is optically conditioned into the detector assembly. The beam splitters and mirror divides passing light through the four band pass filters (wavelength selection) before reaching the photodiodes. The band pass filters are temperature controlled for improved performance. The photodiodes are soldered to the Detector PCB. The Detector PCB performs the signal acquisition and integration. The signal information is then sent to the Sensor PCB.

Overview | 1-3

Lamp & Detector Mounting

The Xenon lamp and detector mounting assemblies are attached to an alignment plate. The Xenon lamp mount contains a UV-grade fused silica, plano-convex collimating lens. Repeatable installation and alignment of the lamp and detector assemblies is achieved by usingone-point keyed connections. Both assemblies are secured using threaded retainers that can be tightened by hand.

User Interface/Host Display

The local user interface is composed of an LCD color display and a stainless steel piezoelectric keypad. The keypad is suitable for use with a gloved hand. The user interface allows the user to set the configuration, test the functionality, and trouble-shoot any problems. The user interface is powered by the host display board. In addition to enabling the local interface, the host display board also allows for remote connectivity through

Ethernet and Modbus communications.

Sensor Board

The sensor board controls the main operations of the analyzer. These operations include sample measurement, signal processing, calculations, monitoring of temperatures and pressures, and providing analog and relay outputs.

Sample Conditioning (Oven) Enclosure

Sample Cell

Demister

Aspirator

Oven Enclosure

Aspirator Heat Exchanger

Cell Isolation/Steam

Blowback

Low Pressure

Operator

Heater

Zero Flush Heat

Exchanger

Flange RTD

Figure 1-4. Oven Enclosure (interior)


Figure 1- 5a Flow Diagram. No Steam Blowback

Figure 1- 5b Flow Diagram. With Steam Blowback

Overview | 1-5

Light Tube/Mirror Block Assembly

The oven optics consist of a light tube and mirror block assembly. The light tube is used to maintain optical alignment. An RTD is mounted to the light tube to monitor cell temperature. Due to the slow thermal response of the light tube, the RTD response is a better indication of the sample system components than if it was mounted in the air. The mirror block includes two second surface mirrors 90 degrees to each other. The two mirrors redirect the light from the Xenon lamp through the sample cell back to the detector assembly.

Probe

The standard probe is a ½” 316 stainless steel tube with a wall thickness of 0.035”. The probe has a standard length of 36” and can be trimmed to final length at installation. Longer probe lengths are also available upon request.


Demister

The demister is used to condense sulfur vapor in the sample stream by lowering the sample gas temperature to 129 °C. The demister cooling is done by injecting air around the central demister tube that has been fitted with heat transfer fins.

Two coalescing pads (one Teflon® pad and one stainless steel pad) are located inside the demister. The demister pads provide increased surface area to help condense the sulfur vapor present in the stream. The air or nitrogen that is used to cool the demister originates from SV1 (solenoid valve 1) on the solenoid valve manifold in the electronics enclosure. The air or nitrogen enters the oven through the tube bushing assembly. The demister temperature is measured by RTD 2.

Sample Cell

The sample cell module consists of either a 2.5” (6.35 cm) or 5” (12.7 cm) 316 stainless steel cell body, two UV-grade, fused silica windows, two Teflon® gaskets, and two retaining rings. The fused silica windows are O-ring sealed at both ends.

The retaining rings and Teflon® gaskets hold the window against the O-rings.

The cell body has two ¼” Swagelok tube fittings to couple with the rest of the sample system. The sample cell is secured to the light tube via 1 SST plate as well as a thumb screw located below the center of the cell body.

Aspirator

The aspirator pressure regulator and proportional solenoid valve (PSV) control the flow of instrument air or nitrogen through the aspirator. The air flow to the aspirator enters through the tube bushing assembly into the oven where the aspirator drive air is pre-heated by an aluminum heat exchanger. There is also a check valve in series with the aspirator drive air. The gas flow produces a slight negative pressure in the cell to move process gas through the sample cell. The desired sample flow rate is 1.5 ±

0.5 liters-per-minute.

The manifold assembly is located in the electronics enclosure. A part of that assembly is a small gauge (Item 60, Figure 1-6).

Adjust the aspirator pressure regulator to produce an output of approximately 10 PSI above process pressure. The analyzer will control the duty cycle to a PSV to keep the sample flow rate at the desired level. Alternately, the analyzer can be configured to manually set the PSV duty cycle.

Overview | 1-7

Heater

The sample system enclosure is electrically heated using a 400 W heater assembly. The heater assembly contains two RTDs for heater fin temperature feedback and over-temperature protection. One SIL 2 rated “Temperature Signal Converter” is wired into the power loop for over-heating protection.

Steam Blowback Valve (Optional)

Steam blowback is an optional feature. When selected, a three-way valve (FV3) is used to direct steam back through the demister and process probe. Steam blowback is used to reduce the build up of salts in the demister. The valve is actuated using a high temperature, low pressure (50 psig) pneumatic operator. The valve and operator are located inside the oven. The outlet of the demister is connected to the common port of the three-way valve. During normal sampling, the valve position is such that the sample gas is directed to the sample cell. During steam blowback, the valve is switched and steam is directed through the demister, isolating the sample cell at the same time.

Heat Exchangers

Two ¼” aluminum heat exchangers are used in the sample system. One of the heat exchangers (HE2) is used to pre-heat zero gas. During zero flush,

SV2 opens allowing air or nitrogen to flow through a protective check valve (CV2) and flow control orifice (O2). The zero gas supply is heated before flushing out the sample cell and coming into contact with sample system components that must remain at oven temperature. The second heat exchanger (HE1) is used to pre-heat the aspirator drive. During normal sampling, air or nitrogen flows through the heat exchanger and protective check valve (CV1) using PV1 to control the flow. The aspirator gas supply is heated before contacting the aluminum aspirator and pipe flange that must remain at oven temperature.


Customer Connection Enclosure



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

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



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Figure 1-7a. Customer Connection Enclosure.

All customer power and signal connections are made within the customer connection enclosure located below the electronics enclosure. Signal con nections are provided for Ethernet, Modbus, Alarm Relays, Analog Out puts, and Remote Inputs. The analyzer supports FTP and Telnet functions over an Ethernet connection. The analyzer supports both ModbusRTU and Modbus/TCP communication protocols. There are four relays: system alarm, data valid, and two programmable relays. There are four configu rable (4-20 ma analog outputs). There is one remote input which can be used to initiate one of the following options: Photo Span Calibration / zero calibration /Steam Blowback.

See Appendix A for all model options wiring diagrams.

Overview | 1-9

Figure 1-7b

Interconnect Wiring Diagram.


Customer Drawing Package

The standard customer drawing package includes four drawings.

1. System Block Diagram: Provides overview for complete system and end user utility requirements.

2. Field Unit Arrangement: Displays the external and Internal arrangement of system componants and provides main system dimensions.

3. Field Unit Installation: Provides installation instructions for system and probe installation.

4. Flow Diagram: Provides complete flow diagram and logic table for periods and valves.

5. Interconnect Wiring: Details power and signal connections inside the customer connection enclosure.

Overview | 1-11

Operation

Timing Sequence

All analyzer functions are broken down into 14 timing periods. Periods 1 –

11 are fully time-programmable.

Periods 1 – 2

Periods 3 – 4

Periods 5 – 8

Periods 9 – 11

Special “Hold”

Period 12 – 14

Zero calibration cycle.

Sample cycle.

Normal zero and photo span calibration cycle.

Steam blowback cycle.

Do not have timers and are used to stop the analyzer in a specific state (flush, hold, or sample). These special periods are primarily used for troubleshooting purposes.

Figure 1-8 outlines the normal cycles and special periods indicating all of the valve states and default timing. Refer to Appendix C for detailed information.

Period

Sample Cycle

1

2

3

4

5

6

7

Name

Special

Flush

Flush &

Zero

Sample

Flush

Track

Sample

Flush &

Zero

Track Zero

Photo Span

Calibration

Time

(s)

SV1 Demister

Normally

Closed

0 Controlling

60 Controlling

SV2-Flush Solenoid

Normally

Open

Deenergized

Deenergized

Open

Open

60 Controlling Energized

SV3-Steam

Blowback

Solenoid

Normally Closed

De-energized

De-energized

Closed De-energized

FV3-Steam

Blowback Valve

Steam Blowback

Normally Closed

Closed

PV1-Aspirator

Proportional

Valve

Normally

Closed

Closed

Analog

Outputs

Next

Period

Hold 2

Data

Valid

Relay

Off

Closed

Closed

Closed

Open

Hold

Hold

3

4

Off

Off

N/A Controlling Closed De-energized Closed Open

Tracking

Note

2

On

Hold 6 Off 60

0

60

Controlling

Controlling

Controlling

8

9

10

11

12

13

14

Track Photo

Calibration

Pre-Steam

Flush

Steam Blow

Back

Post Steam

Flush

Continuous

Flush

Continuous

Hold

Continuous

Sample

10

10

20

60

Controlling

Controlling

Controlling

Controlling

N/A Controlling

N/A Controlling

N/A Controlling

Energized

Deenergized

Deenergized

Deenergized

Deenergized

Deenergized

Deenergized

Deenergized

Deenergized

Energized

Energized

Open

Open

Open

Open

Open

Open

Open

Open

Closed De-energized

Closed

De-energized

De-energized

De-energized

De-energized

De-energized

Energized

De-energized

De-energized

De-energized

Closed

Closed

Closed

Closed

Closed

Open

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Open

Hold

Hold

Hold

Hold

Hold

Hold

Hold

Hold

Hold

7

8 or

9

Note

3

3

Off

Off

Off

10

11

Off

Off

5

Note

1

Note

1

Note

1

Off

Off

Off

Off

Figure 1-8.1: Analyzer Timing and Control Summary With Steam Blowback


Period

Sample Cycle

Zero and Photo Span Calibration

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Name

Special

Flush

Flush &

Zero

Sample

Flush

Track

Sample

Flush &

Zero

Track Zero

Photo Span

Calibration

Track Photo

Calibration

Pre-Steam

Flush

Steam Blow

Back

Post Steam

Flush

Continuous

Flush

Continuous

Hold

Continuous

Sample

Time

(s)

0 Controlling

SV1 Demister

Normally

Closed

60

60

N/A

60

0

60

10

10

20

60

N/A

N/A

N/A

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

De-energized

SV2-Flush Solenoid

Normally Open

Open

De-energized

Energized

Open

Closed

Energized

De-energized

De-energized

De-energized

De-energized

De-energized

De-energized

De-energized

De-energized

Energized

Energized

Closed

Open

Open

Open

Open

Open

Open

Open

Open

Closed

Closed

Figure 1-8.2: Analyzer Timing and Control Summary Without Steam Blowback

Open

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Open

PV1-Aspirator

Proportional

Valve, Normally

Closed

Closed

Closed

Open

Overview | 1-13

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SPECIFICATIONS


Ranges

Performance

Standard Range:

0-2% H

2

S and 0-1% SO

2

High Range:

0-4% H

2

S and 0-2% SO

2

Other ranges available upon request.

All performance specifications are based on normal operation that includes periodic zero and photo span calibration.

Accuracy ± 1% of full scale range

Reproducibility ±1% of full scale range

Repeatability <1% of full scale range

Noise ± 0.5% of full scale range

Zero Drift <0.5% of full scale range

Response Time

90% in less than 15 seconds, typical with photo noise at default

Cell Battery Type

Calibration

Primary Lithium poly-carbon monofluoride (Li/CF(n))

Size: Coin

Operating Temp: -30 ° C to +80 ° C

Nominal Voltage = 3.3 V

Minimum Internal Resistance = 3.1 m Ω

Capacity = 190 mAh

Weight: 2.5 g

Dimensions = 3.2mm (H) X 20mm (D) +/- 0.3mm

Factory calibrated; Automatic calibration capability

(no hazardous or toxic calibration gases are needed)

Specifications | 2-1

Communication

Local User

Interface

Analog Outputs

Digital Output

Serial

Communications

AMEVision; 4.2” LCD color, 1/4 VGA display; 19-key piezoelectric keypad (suitable for use with a gloved hand)

Four 4 to 20mA analog outputs are electronically isolated from the controller, but not each other.

(Self Powered)

System Alarm, Data Valid, and two configurable digital outputs (30 VAC, 60 VDC, 10 VA, maximum, resistive load only)

RS-485 serial communication; Modbus RTU; twowire half duplex; 9600 baud. Modbus query rate limited to 30 queries per second. Modbus TCP supports a single TCP master.

Ethernet

Fast Ethernet; 100 Mbit/s. Modbus query rate limited to 30 queries per second. Modbus TCP supports a single TCP master.

USB Connectivity USB 2.0

Remote Input One (1) digital input (user configurable)

Purge Alarm

Environmental

Conditions

Enclosures

Rating: 2 Amps, 240 VAC Resistive

Alarm Connection: Loss of Purge Pressure; Form C

Contact

Ambient Temperature Limit

-20° to +60°C ( -4° to +140°F )

The analyzer must be shaded from direct sunlight.

Electronics and oven enclosures, backplate, and keypad are 316 stainless steel.

Customer connection enclosure is made from cast aluminum.


Utility

Requirements

Power Consumption (specified at time of purchase)

120 VAC (105-132 VAC), 47-63Hz, 500W

OR

240 VAC (209-264 VAC), 47-63Hz, 500W

Instrument Air

Supply Instrument Air 60 lb max. (60psig) (414kPa)

Pressure 379-517 kPa (55 to 75 psig / 3.8-5.2 barg)

Air Consumption (Fast Purge) = 1.023 kg/min and

2.262 lbm/min

Air Consumption (Trickle Purge) = 0.00138 kg/min and 0.00304 lbm/min

Air Consumption (Zero and Aspirator at 75 psig) =

0.169 kg/min and 0.373 lbm/min

Air Quality: As per ANSI/ISA standard 7.0.01-1996)

Steam

Ball Valve Jacket Pressure: 517-690 kPa (75 to 100 psig \ 5.2-6.9 barg)

Air Consumption (Fast Purge) = 1.023 kg/min and

2.262 lbm/min

Air Consumption (Trickle Purge) = 0.00138 kg/min and 0.00304 lbm/min

Air Consumption (Zero and Aspirator at 75 psig) =

0.169 kg/min and 0.373 lbm/min

Blowback Pressure: 207-345 kPa (30-50 psig / 2.1-

3.5 barg).

Specifications | 2-3

Figure 2-1, 888-ATEX Label


INSTALLATION AND START-UP

Prior to Installation

!

CAUTION

Installation drawings found in this section are for typical installations. Any customer drawings (CDs) supplied with the system supersede the drawings included here.

!

WARNING

The installation of the analyzer must be in accordance with all of the customer (end user) and local regulatory standards and procedures.

There are no operator-serviceable components inside the analyzer.

Refer service requirements to qualified personnel.

!

WARNING

Read this entire section before beginning installation of the Model 888

Analyzer. Failure to do so, and / or use of the analyzer in a manner not specified in this manual, may impair the protection against fire, electrical shock and personal injury originally provided by this equipment.

Personnel Technical Level Required for Installation

Installation must be performed by qualified persons in accordance with local codes and NEC and CEC codes, where applicable. Prior to installation please consult the local codes in order to understand what is acceptable. To the extent this information is not consistent with local codes, the local codes should be followed. It is recommended that only trained personnel perform these installation steps.

Installation and Start Up | 3-1

Analyzer Site Preparation

The 888 Tail Gas Analyzer is approved for installation in hazardous areas classified as Zone 1, ( Per ATEX & IECEX).

The analyzer must be installed on a horizontal run of the tail gas pipe. A site plan should be prepared defining the system mounting location and provisions for power/data interconnect wiring. It is highly recommended that a servicing platform equipped with safety railings be installed at the analyzer mounting site.

Unpacking and Inspection

Remove components from the packing case(s) carefully; check contents against packing list. Open the enclosures and inspect all components for obvious damage and broken/loose parts or fittings. The Demister/Inlet

Valve assembly is packaged separatly and shipped within the analyzer crate to avoid damage during transportation.

Notify the carrier and AMETEK Service (1-800-222-6789) immediately if parts are missing or damage is found.

Space Requirements

Refer to Figure 3-1 (or the “Field Unit Installation” drawing from the Customer Drawing Package). The analyzer weighs approximately 105 kg (230 lbs).




Installation Guidelines

1. If using an existing sample tap, make sure that it is internally free of solidified sulfur.

The Model 888 returns the sample to process through the annular space around the O.D. of the probe tube. In most cases, the 1/2-inch

O.D. probe tube will be running through a 1-inch bore, leaving a 1/4inch annulus for sample return. If this annular space is blocked with sulfur, the analyzer’s aspirator cannot function properly and may impede sample flow.

2. The analyzer’s mounting flange has threaded studs (flat washers and nuts provided), welded to the flange. Leave adequate clearance under the analyzer for ease in re-installing the nuts. When lowering the analyzer onto the sample tap, guide the studs into the corresponding holes on the sample tap flange, then attach the flat washers and nuts.

Make sure that fittings or other objects do not interfere with rotation of the nuts.

A gasket is recommended between the analyzer flange and process valve to prevent process gas leaks.

3. The analyzer is shipped with the demister, sample valve and probe packaged separately from the cell oven enclosure to protect the demister during shipping. Installation instructions provide assembly details.

4. Install the probe only after the analyzer is already in place on the sample tap to minimize escape of process gas.

It will be necessary to open the steam-jacketed ball valve on the sample tap during the probe installation process; be sure the valve handle is accessible after probe installation.

5. Be careful when removing the demister temperature sensing probe

(RTD) from the cell oven when installing the probe. The RTD is not designed to be repeatedly bent back and forth or forced into small radius bends. If it must be bent at all, do so slowly and gently, and in a greater than a one-inch radius.

6. When installing the demister assembly, fully insert the tubing in the fitting before attempting to thread the nuts and be careful not to cross thread the Teflon nuts on the stainless fittings. AMETEK will not be responsible for damage to these fittings.


Sample Tap Preparation

The analyzer is pipe-mounted to the process pipe using a probe, ball valve and flange.

!

WARNING

The sample pipe contains highly toxic and corrosive substances.

Proper personal protective equipment including fresh air breathing apparatus, eye protection, and skin protection MUST BE worn when installing the sample tap.

As an additional precaution against escape of toxic gases, AMETEK recommends that a blind flange be installed on the sample tap flange until the analyzer is installed.

!

CAUTION

Note the bolt-hole pattern and orientation of the analyzer mounting flange in Figure 3-1. The tail gas pipe flange bolt pattern must line up with the analyzer flange bolt pattern. This will provide two possible analyzer mounting orientations. AMETEK recommends that the analyzer be installed with the backplate parallel to the tail gas pipe.

!

CAUTION

Ensure that all parts of the sample tap, from the very beginning of the installation process, are kept heated at a minimum 150 °C and insulated from the process pipe to the bottom of the analyzer (including flanges). This will prevent plugging the sample tap with solid sulfur which would interfere with commissioning the analyzer.

AMETEK recommends that a heated, 1-inch ball valve with a 2-inch,

150 lb. raised face flange (AMETEK PN 203176001 Steam Jacketed

Ball Valve or equivalent) be installed on the nozzle.

1. Install the recommended weld neck (two-inch, 150 lb raised face flange) at a 90° angle to the top of a horizontal run of the tail gas pipe.

2. Mount the analyzer directly to this valve flange. Ensure that it is installed plumb and level or the analyzer will not stand straight upon installation (minor angles will not affect analyzer operation). If it is


necessary to stand the analyzer off the process pipe by more than 12 inches, use a steam jacketed spool piece. If nozzle length is less than six inches, a heat trace is not necessary. If the nozzle is six to 12 inches, it should be heat-traced at a minimum of 150 °C. Weld necks greater than 12 inches in length are not recommended.

Never place the analyzer at such a standoff distance that a sample probe length greater than five feet is required.

3. The sample tap valve handle should be installed so that the handle must be turned down (toward the pipe) to open the valve. If it is installed in such a way that the handle must be turned up (toward the analyzer) to open the valve, the analyzer enclosure may interfere with its being able to fully open.


Installation Procedure

!

WARNING

The sample gas contains highly toxic and corrosive substances. Proper personal protective equipment including fresh air breathing apparatus, eye protection, and skin protection MUST BE worn when installing the sample tap.

Refer to Figures 3-1 and 3-2 for locations of system components.

1. Locate and remove the bolts, nuts, washers, and lock washers from the mounting hardware bag. Retain this hardware for use in Step 5.

2. The sample return valve (FV2), located at the bottom of the aspirator, is a 3/8” valve which is closed when the handle is in a horizontal position and open when in a vertical position.

!

CAUTION

Verify that this valve (FV2) is CLOSED (horizontal) before proceeding. If it is left open, toxic gases from the tail gas line can flow back through the sample system while the probe is being installed.

3. Verify that the main sample valve on the tail gas pipe is closed. At this point, ALL PERSONNEL IN THE IMMEDIATE AREA MUST USE

FRESH-AIR BREATHING APPARATUS.

4. Remove the blind flange from the ball valve. Test to make sure that the valve is not leaking toxic process gases. If toxic gases are not detected in the area, it is safe to remove the fresh-air apparatus until the probe installation (Step 8).

5. Install a gasket on the top of the steamjacketed main sample valve. Using suitable lifting equipment, lower the analyzer into place so that:

- The analyzer back plate is parallel with the tail gas pipe, and

!

- The sample inlet flange and main sample valve flange bolt patterns line up. Use the nuts, washers, and lockwashers (set aside in Step 1) to bolt the flanges together. Use a calibrated torque wrench to torque the bolts in a cross pattern to 54.25 N-m (40 ft.-lbs).

CAUTION

The integrity of the connection between the analyzer sample inlet flange to the tail gas pipe flange is critical as it provides the primary support for the analyzer.


6. Connect clean dry instrument air supply to the 1/4-inch bulkhead on the right-hand side of the cabinet. If air supply quality is in question, connect through two air/oil separators. Back out the air regulator screw so that air lines on the analyzer are not pressurized.

7. Remove the screws from the cell oven cover plate at the top of the oven enclosure. Set aside the four screws. The cover plate must be loosened, but may not have to be removed. The screws must be reinstalled and tightened after probe installation.

8. Prepare the probe. The probe tube is 1/2-inch diameter, 316 stainless steel tubing. The probe supplied is ~910 mm (36 inches) long. Cut the probe to a length that results in the probe’s end extending into the pipe 1/4 to 1/2 of its diameter.

Installing the Probe

Refer to Figures 3-2a fand 3-2b or location of all inlet, valve and vent locations.

The probe enters the oven through a Conax gland with a Teflon ferrule which uses a nut to seal the probe. The nut can be tightened or loosened to slide the probe, pull it out or insert another probe for service or maintenance.

1. Install the probe into the 1/2-inch tube fitting on the sample inlet ball valve (FV1) using the supplied stainless steel ferrule. Make sure the fitting is tight and leak free.

- Make sure the flange fitting components (nut, SST ferrule, and Teflon® seal) are loosely installed on the flange fitting.

- Verify that the sample inlet ball valve (FV1) is closed.

- Scribe a mark on the probe just under the ball valve to aid in orienting the probe correctly.

!

WARNING

All personnel in the immediate area MUST wear fresh-air breathing apparatus for the remaining installation steps. Do not remove breathing apparatus until installation is complete and all fittings have been checked for toxic gas leaks.


2. Install the probe through the sample inlet flange, main process valve, and into the process:

-

- Slide the probe tube down into the flange fitting. If the probe tube is longer than 16 inches, it may be necessary to remove the sample oven cover plate and lower the probe/valve assembly through the top of the sample oven. Tighten the compression fitting enough to create a seal around the probe while still allowing the probe to slide.

Depending on the length of the probe, it may be necessary to remove the valve handle (FV1) for the valve to fit through the opening in the top of the sample oven. If this is the case, the handle must be placed in the closed position before removing the handle.

- Verify that the analyzer sample inlet ball valve (FV1) is closed and remains closed. Continue to slide the probe down through the flange.

When the probe tip touches the ball of the main sample valve, back the probe out 1/2” and etch a mark on the probe at the top of the flange tube fitting. Open the main sample valve slightly and check for leaks, continue inserting the probe as far as possible. Fully tighten the flange compression fitting. This etched mark will be used for probe removal and replacement.

Figure 3-2a. Inlet, Valve and Vent Location- No Steam Blowback


Figure 3-2b. Inlet, Valve and Vent Location- With Steam Blowback


Item

FV1

Description

Valve, Sample Inlet

DEM

FV2

CELL

CELL

Demister Assembly

Demister Pad, Teflon

Demister Pad, Stainless Steel

Valve, Sample Return

Cell Assembly, 1% H2S / 2% SO2

Cell Body, 1% H2S / 2% SO2

Cell Assembly, 2% H2S/4%SO2

Cell Body, 2% H2S/4%SO2

O2

O1

O3

HE1

ASP

FV3

CV1

CV2

Window, Fused SIlica, 1.5”

O-ring, Viton, 028

Gasket, Teflon

Aspirator

Valve, Steam/Cell Isolation

Check Valve, Aspirator

Check Valve, Zero Flush, 200 micron orifice

Orifice, Zero Flush, 200 micron

HE2

PCV1

PCV2

PS1

Orifice, Pressure Transducer Purge, 50 micron

Orifice, 400 micron

Heat Exchanger, Aspirator Drive, Alum Tube

Heat Exchanger, Zero Flush, Alum Tube

Pressure Regulator, Manifold, 0-100 psig

Pressure Regulator, Aspirator, 0-30 psig

Pressure Sensor, Manifold, 0-100 psig

PS2

S1,S2,S3,

Pressure Sensor, Aspirator, 0-30 psig

Solenoid Valves (Demister, Zero Flush,

Steam Blowback/Cell Isolation)

Valve, Proportional Control, Aspirator PV1

RTD1

RTD2

RTD3

PT

GA1

PCV3

RTD, Cell

RTD, Demister

RTD, Flange

Pressure Transducer, 0-50 psia

Gauge, Aspirator, 0-30 psig

Pressure Regulator, Purge, 0-60 psig

PI1 Gauge, Purge, 0-60 psig

Table 1. Parts Legend - Refer to Figure 3-2.

Part No.

271446001

883026901

272177001

271653001

273383001

883034901

883077001

883034902

883077002

200887001

202813026

880042001

407300902

883096001

203790001

883035001

273454001

273455001

272080001

N/A

N/A

301-0431

301-0430

403464902

403464903

301-0424

883038901

883095001S

273402001

883095002S

273291001

251744000

203188003

273472001


Installing the Demister

The demister is a white insulated assembly (Figure 3-3). The sample goes through the demister at a lower temperature than the rest of the oven. If there are droplets of sulfur in the sample stream, they will condense and fall away from the sample.

There is an RTD at the top left of the demister which measures the temperature. Having the RTD on the side of the demister makes it easier to remove the demister when servicing or replacing since the RTD can retract.

!

WARNING

Take necessary precautions to ensure that neither the analyzer sample inlet ball valve (FV1) nor the sample return valve (FV2) is inadvertently opened during the demister installation procedure.

Figure 3-3. Internal Layout.

1. Refer to Figure 3-2. Place the demister on top of the sample inlet ball valve (FV1). Make sure that the 1/8” tube fitting is facing the electronics enclosure.

2. Locate the 1/8” demister RTD from the electronics enclosure and insert it into the 1/8” fitting towards the top of the demister.

3. Push the demister onto the probe as far as necessary until it meets with the ¾” compression fitting connecting the demister to the sample inlet ball valve. It may be necessary to slightly loosen the compression


fitting on the sample inlet flange and pull the probe/valve assembly up slightly to line up the demister RTD connection. Loosen only as required.

!

CAUTION

Make sure that the seal between the probe tube and the compression fitting is maintained so that no process gas leaks around the fitting.

4. Retighten once the ¾” compression fitting is secured.

5. Mate the outlet of the demister to the installed sample system components.

6. Install the remaining tubing connections packaged separately. Refer to the flow diagram in the customer drawing package for appropriate connections.

7. Using recommended tightening procedures, verify that all compression fittings inside the cell oven are tightened.

8. Test all sample tap connections and the sample inlet ball valve to make sure there are no toxic process gas leaks. When satisfied that no leaks are present, remove the breathing apparatus and proceed with the remainder of the start-up procedure.

9. Remove handle of the steam-jacketed main sample ball valve to ensure valve cannot be closed while the sample probe is in place. Secure handle nearby so that it is available when needed.


Purge Installation

Figure 3-4. X-Purge Installation.

1.

1. Maximum non-hazardous area voltage must not exceed 250 V.

2. Installation in accordance with Canadian Electrical Code (CEC), Part I for installation in Canada.

3. Install in accordance with the NEC (ANSI/NFPA 70) and (ANSI/ISA RP

12.6) for installation in the United States.

4. Install in accordance with the IEC60079-11 and IEC60079-14 for ATEX and IECEx installations.

5. Resistance between barrier ground and equipment ground must not exceed 1-Ohm.

6. Wiring for alarm circuit and supply circuit must be routed separately or each must be protected by a grounded-shield cable.


Electrical Connections

!

WARNING

Check ground continuity to all electrical enclosures before applying power.

Connections to the AC source must be made only by qualified electricians. AC source must be single-phase, grounded-neutral type.

Cable glands suitable for use in a Zone 1 area must be used for all field wiring. The enclosure has been machined to accept M25-size glands.

!

WARNING

The Customer Connection Enclosure of the 888 must be terminated in accordance with country and local electrical codes.

















Figure 3-5a. Customer Connection Enclosure.

1. The 888 Analyzer is considered outdoor, permanently connected and stationary equipment. It is supplied, as ordered by the customer, configured as either a 120 VAC or a 240 VAC unit and contains voltagedependent subassemblies. Do not attempt conversion in the field by unqualified personnel. Power requirements for the equipment are found both in the Specifications section of this manual and on the labels applied near the power inlet located on the equipment or inside the electronics enclosure door.

2. AC mains power connection to the Analyzer is made in the enclosure mounted below the electronics enclosure. AC power must be threewire, single phase, with line hot (18 AWG), grounded neutral (18


AWG), and separate earth/protective ground (PE) (14 AWG). The Analyzer must be externally connected to an M5 stud via an 11 AWG wire located to the right side of the customer connections enclosure. Refer to Figure 3-5 for connection details. DO NOT CONNECT SPLIT-

PHASE POWER TO THIS ANALYZER. Six (6) M25 holes are provided for power and signal cable gland entry/installation. If the incoming power cable is too large, a separate junction box must be provided that can accept the main cable and suitable jumpers used from this box to the analyzer’s junction box. Ensure that all unused M25 holes are plugged with hardware appropriate to the area classification.

Figure 3-5b. Interconnect Wiring Diagram.

Refer to Appendix A for wiring diagrams for all model options.

As a permanently connected piece of equipment without an accessible power switch, the installation must have the following characteristics:

- The installation must include an external disconnect device, such as a switch or circuit breaker, included as part of the installation. The electrical specifications of this device must accommodate the power and environmental requirements of the equipment for the particular application.


- This disconnect device must be in close proximity to the equipment and in easy reach of an operator.

- The device must be permanently marked as the disconnect device for this equipment.

3. Signal I/O connections are also made in the same enclosure mounted below the electronics enclosure. Refer to Figure 3-4 for details. All customer wiring must have a minimum working voltage of 300VRMS.

Refer to the Specifications section (Chapter 2) for customer signal input voltage and current restrictions. A separate junction box may be required if the signal cables are too large in diameter to fit the M25 entry holes.

System Start-Up and Operation

Leak Checking

Before power is applied and before the sample inlet valve is opened to the process gas stream, it is necessary to ensure that no leaks are present in the sample system.

!

CAUTION

It is recommended that the sample system be leak checked after any maintenance or modifications.

Leak Checking (without power)

Necessary equipment: Pressure gauge, shut-off valve, and a regulated air supply. Arrange the components as indicated below.

Regulated

Air Supply

→ Shut-Off

Valve

→ Pressure

Gauge

→ Utility

Port of Analyzer

Procedure

• Close both the sample inlet and return valves on the analyzer.

• Supply 50 psig to the utility gas inlet and lock it in using the shut-off valve.

• Monitor the pressure gauge for any drops in pressure.


Purging the Electronic Enclosure

A purge controller and vent system maintain a positive pressure preventing explosive gases from entering the electronics enclosure. On start-up, the purge controller will automatically monitor the purge gas flow to ensure a minimum of five (5) air exchanges before providing power to the electronics enclosure . The controller then monitors the enclosure’s internal pressure. In the event that positive pressure is lost, power will be disconnected from the electronics. All input and output signals are disconnected by relays in the flameproof enclosure should power be interrupted by the purge controller.

!

CAUTION

A regulated supply of instrument air or nitrogen must be connected to the purge gas regulator. The regulator is located to the right of the electronics enclosure. Refer to Chapter 2 for specifications.

!

CAUTION

The installer must install a second pressure regulator on the input of the unit to mitigate any risk from a single regulator failure in the system.

!

CAUTION

Once the analyzer is installed on a process gas pipe, instrument air pressure must be maintained at all times, even when the analyzer is powered down or off-line, to keep corrosive gases and moisture out of the enclosures and prevent damage.


Figure 3-6. Purge Controller and Default Password.

For the Electrical Enclosure Purge System to operate properly the enclosure’s door must be securely closed.

Adjusting the Purge Controller

The purge controller is programmed at the factory to run automatically.

However, it may be necessary to make adjustments based on the utilities present at the installation site.

1. Connect a regulated source of instrument air or nitrogen to the purge inlet.

2. Locate the terminal block inside the flameproof enclosure. Apply mains power to the terminal block.

3. Once power has been applied, the purge controller will start a fast purge of the electronics enclosure.

If a fast purge does not start:

Check the blue “safe pressure” indicator on the purge controller to ensure that it is turned on.


If the blue safe pressure indicator is not turned on:

Locate the adjustment valve at the top of the purge controller. Use a flatblade screwdriver to adjust the pressure. (MAX 60psig)

Turn the valve slowly counter-clockwise until the blue indicator turns on ensuring that the purge enclosure senses sufficient pressure.

4. The purge controller will purge the electronics enclosure for a minimum of five (5) air exchanges. After a short period, the time remaining for the fast purge will be displayed on the purge controller. Once the time displays, it will take three (3) minutes for the fast purge to complete.

5. The gauge on the regulator at the right side of the panel should read a nominal 104 kPa (15 PSI) during the fast purge. Adjust the regulator if necessary to read the nominal pressure.

6. Once the fast purge is complete, the purge controller will connect power to the analyzer electronics. The flow rate will drop noticeably and the gauge on the purge regulator will increase several PSI. This change in the pressure reading is normal. Do not readjust the regulator.

Refer to the Pepperl and Fuchs 6000 Series Purge Controller Manual for further details on the purge controller. *visit: http://files.pepperlfuchs.com/selector files/navi/productinfo/dect/tdoct1372c org.pdf to get an up-to date Purge Controller Manual.

Default passwords are indicated in Figure 3-6.

System Operation

Analyzer Security - Password

The prompt for a password comes up only if the user attempts to modify a screen or initiate an option.

When the user attempts to modify a field or initiate an action, the password request screen pops up. If no password is entered, the user cannot change any of the values or initiate any actions but is able to view all of the information. Entering the correct password allows the user to perform the functions selected.


The default time out is 5 minutes but the time-out period is programmable. If the password has timed out, the user will be prompted to log in again.

The analyzer pasword is factory set as“2222” and allows the user to access all of the functions available in the Actions, Configure and some of the

Diagnose menu screens.

Starting Normal Operation

1. Connect the air supply and set the pressure regulator for approximately 55-75 psig.

2. Set the Aspirator supply pressure for 5-10 psig above expected process pressure by using Regulator (PCV2) and Pressure Gauge (GA1) mounted on the Manifold.

3. Open the sample inlet ball valve (FV1) and the sample return valve

(FV2) at the bottom of the aspirator. Close and tighten the latches on oven enclosure.

4. Verify that the electronics enclosure and detector enclosure doors are closed and properly secured.

5. Apply AC power and note controller display screen activity.

Figures 3-7a. Start-up and Configuration Pressures screen.

The analyzer will start in Period 1, Special Flush, and will step to Period 2,

Flush & Zero, when the default Period 1 timer times out. Air (or nitrogen) will be flowing back through the sample system; this prevents sample gas from entering the system until the sample cabinet is up to proper operating temperature (nominally 150°C). Refer to the logic table (Fig. 3-9b or

3-9e) alongside the flow diagram in the customer drawing package or

Tabel on Page 3-25 of this manual.


When the analyzer components reach operating temperature, the controller will perform an auto-zero of the photometer and then enter Period 3,

Sample Flush.

!

CAUTION

Sample will not flow through the cell until positive flow is attained by adjusting the aspirator pressure.

Allow 2-4 hours for complete thermal stabilization of sample cell and demister.

Setting the Sample Gas Flow

To set the sample gas flow, navigate to the menu item CONFIGURE on the HOME screen and press the (ENTER) key.

Figure 3-8a. Controller Home Screen.

Use the right and left navigation arrows to advance to the PRESSURES screen. Press the ENTER key to select the PRESSURES menu.

Figure 3-8c. Pressure Configuration

Figure 3-8b Pressure Menu

Use the arrow keys to navigate to Aspirator Pressure Configuration and press the ENTER key.


Figure 3-8d. Configuration Screen.

1. Locate the aspirator regulator pressure gauge (GA1). Set the aspirator regulator pressure until the gauge reads approximately 10 PSI above the process pressure.

2. Make sure the Aspirator Overide is in the NO position.

Neutral, de-activated position

3. Check that the flow setpoint is set to 1.5.


4. The analyser will now regulate sample flow automatically in Period 4

(Measure).

5. Press the “X” key to exit to the previous screen.

Figure 3-9a. Configure Pressures screen

6. Press # to exit to the Home screen .

Analyzer Timing

All Model 888 analyzer functions are broken down into 14 timing periods.

See Logic Table below.

• Periods 1 - 4 are the normal Sample cycle and Zero cycle periods.

• Periods 1 - 11 are fully programmable and are run for a length of time in seconds.

• Periods 12 - 14 are special “hold” state periods.

Descriptions of events during various timing periods are for typical operation only. Some events can be altered by changing period timers.


Period

Sample Cycle

1

2

3

4

5

6

7

8

9

11

Name

Special

Flush

Flush &

Zero

Sample

Flush

Track

Sample

Flush &

Zero

Track Zero

Photo

Span

Calibration

Track

Photo

Calibration

Pre-Steam

Flush

Time

(s)

0

60

60

N/A

60

0

60

10

10

SV1 Demister

Normally

Closed

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

Controlling

20 Controlling

Post

Steam

Flush

60 Controlling

Energized

SV2-Flush Solenoid

Normally Open

De-energized

De-energized

Open

Open

Closed

Energized

De-energized

De-energized

De-energized

Closed

Open

Open

Open

De-energized

De-energized

De-energized

De-energized

Open

Open

Open

Open

Logic Table-Fig. 3-9c (For Analyzer With Out Steam Blow Back.

PV1-Aspirator

Proportional

Valve, Normally

Closed

Closed

Closed

Open

Open

Closed

Closed

Closed

Closed

Closed

Closed

Closed


Period

Sample Cycle

Zero and Photo Span Calibration

1

2

3

4

5

6

7

8

9

Name

Special

Flush

Flush & Zero

Time

(s)

SV1 Demister

Normally

Closed

0

SV2-Flush Solenoid

Normally

Open

Controlling De-energized Open

60 Controlling De-energized Open

Sample

Flush

Track

Sample

Flush & Zero

Track Zero

Photo Span

Calibration

Track Photo

Calibration

Pre-Steam

Flush

60

N/A Controlling Energized Closed




10

10

Controlling Energized Closed




11

Post Steam

Flush


N/A Controlling De-energized Open

N/A Controlling Energized

N/A Controlling Energized

Closed

Closed

SV3-Steam

Blowback

Solenoid

Normally

Closed

De-energized

FV3-Steam

Blowback Valve

Steam Blowback

Normally Closed

Closed

De-energized

De-energized

De-energized

De-energized

De-energized

De-energized

De-energized

De-energized

Energized

De-energized

De-energized

De-energized

De-energized

Closed

Closed

Closed

Open

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Closed

Closed

PV1-Aspirator

Proportional

Valve

Normally

Closed

Closed

Closed

Open

Closed

Closed

Closed

Closed

Open

Closed

Closed

Closed

Closed

Closed

Open

Logic Table-Fig. 3-9b (For Analyzer With Steam Blow Back.

Normal Timing Sequence

The Logic Table shows the sequential timing periods 1 through 14. When power is first applied, the controller starts at Period 1 and cycles through to Period 4, the Sample Tracking period. Sample tracking continues indefinitely until one of the following events occurs:

1. When the Zero Timer times out, normally a Zero Cycle is started immediately, but when the option is available, a Steam Blow Back Cycle can also be started. When this timer times out, the Zero cycle begins at

Period 1, steps to Period 2 where the zero offset values are recorded, steps to Period 3 and on to Period 4. This cycle, 1 → 2 → 3 → 4 → 1 and so on, constitutes the normal sampling operation loop.


2. When the Calibration Timer times out, a Calibration Cycle starts immediately. The calibration cycle begins at Period 5 in which the zero offset values are recorded. It then tracks the zero values through

Period 6, steps to Period 7 where the photo span values are verified or adjusted, tracks the span values through Period 8, and returns to

Period 3 to resume the normal sampling cycle 3 → 4.

3. When the Calibration Timer times out and the following occurs, then a

Steam Blow Back Cycle is started instead of a Calibration Cycle.

- The Zero Period parameter, which defines the number of zero or calibration cycles between steam blowback cycles, is not equal to zero; and

- The Zero Period number of zero or calibration cycles have elapsed since the last steam blowback.

4. Steam Blow Back Cycle.

- Period 9 - flushes the system with air

- Period 10 - Steam is flushed back through the demister and probe

- Period 11 flushes the system with air again before beginning the calibration cycle by jumping to Period 5.


Per1

Periodic STEAM BLOW BACK Diagram

Per2 Per5 Per6 Per9 Per10 Per11

Blowback Timer times OUT and Zero Period<> 0

If using the automatic steam blowback function, do not set Blowback

Interval to a value less than 16 or run the cycle more than once a day.

!

WARNING

If your analyzer requires steam blowback to run more than once a day, please contact the Ametek Service Department.

Calibration Span Adjustment

The Model 888 has an optional calibration span adjustment that is performed manually. Use cylinders of H

2

S and SO

2

of known concentrations to validate and/or adjust the calibration of the analyzer.

!

CAUTION

Potentially lethal concentrations of toxic gases such as hydrogen sulfide (H

2

S) and sulfur dioxide (SO

2

) will be present in the analyzer sample system and in the calibration gas supply system. Only personnel who are adequately trained in the handling of these gases should perform this procedure.

Calibration Gas Requirements

Recommended calibration gas mixtures are H nitrogen (as separate mixtures). H

2

S or SO

2

2

S in nitrogen and SO

2

in

concentration should be about

80% of the full-scale measuring range for that component. The delivery pressure for the calibration gas should be adjustable from 0 to 10 psig.

!

CAUTION

Calibration gas mixtures more than six months old are unreliable and should not be used.


Calibration Procedure

1. From the Model 888 HOME screen, use the navigation keys to move to the CONFIGURE button and press the ENTER key to access the

CONFIGURATION sub-menu (Figure 3-10a)

Figure 3-10a. Calibration Screen.

Figure 3-10b. Calibration Configuration.

2. Press ENTER again to access the Calibration Configuration screen

(Figure 3-10b). Use the navigation keys to move to the “H2S and SO2

Calibration” option and press the ENTER key to access the H2S Calibration Configuration screen (Figure 3-11).

Figure 3-11. H2S Configuration: H2S & SO2

3. Use the navigation keys to move to the Span Coefficient fields. Press the ENTER key to select the field and set the Span Factors for both H

2 and SO

2

to 1.00. Press ENTER after each entry.

S

4. Activate Period 12 “Continuous Flush ” by navigating to the option. It will visibly brighten to indicate that it has been selected.


Neutral, de-activated position

5. Press the ENTER key to activate the continuous flush. The gold side of the slider will move to the right to indicate that the flush is activated.

Flush is activated

6. Remove the cap from the Utility port on the right hand side of the cell oven. Connect a tube from the cal gas source to the Utility port and tighten it.

!

CAUTION

A small amount of potentially hazardous process gas may be expelled when the cap is first removed.

7. Activate Period 13 “Continuous Hold ” by navigating to the option. It will visibly brighten to indicate that it has been selected.

8. Press the ENTER key to activate the continuous hold. The gold side of the slider will move to the right to indicate that the hold is activated.

9. Open the valve on the calibration gas source.

10. Wait for the H

2 stabilize.

S or SO

2

concentration reading on the menu screen to

11. Calculate a new value for the H

2

S or SO

2

span factor. Enter the new span factor by navigating to each field as before and pressing the EN-

TER key to add the values.

Span Factor=Calibration Cylinder Concentration /Analyzer Reading

12. After the new span factors are entered, validate the analyzer is reading the calibration gas cylinder correctly by checking the percentages on the screen (Current Value %).

13. Close the valve from the calibration gas source. Activate analyzer Period 12 “Continuous Flush” and wait at least 30 seconds. The H

2

SO

2

readings should now read 0%.

S and

14. Disconnect the calibration gas tube from the analyzer’s Utility port.

Put the cap back on the Utility port and tighten it.

!

CAUTION

A small amount of potentially hazardous process gas may be expelled when the cap is first removed).


15. Press the CANCEL key (#) to return to the HOME screen. Navigate to the ACTIONS button and press the ENTER key.

16. Use the arrow keys to navigate to the Manual Actions screen and press the ENTER key.

Figure 3-12. Manual Actions screen.

17. Use the arrow keys to move to the SAMPLE MEASURE button and press the ENTER key to select it. The analyzer is now back in service.

18. To EXIT, press the CANCEL key (#) to return to the HOME screen.


Analyzer Troubleshooting and Maintenance

Generally, little maintenance is required to ensure the analyzer remains operating at peak efficiency, other than that described in the “Removal and Replacement of Major System Components.” This maintenance, which includes parts that require scheduled replacement and cleaning, is intended to ensure continued and proper operation of the analyzer.

!

WARNING

Before performing maintenance on the analyzer, be sure to follow appropriate actions and precautions to prepare the analyzer for service, such as properly isolating the analyzer from the sample gas stream/ duct, backpurging the sample line (“Flush/Zero” mode), powering down the analyzer (unless it is necessary to keep the analyzer operating), and opening the Electronics Enclosure.

For certain procedures, such as replacing source lamps, it is not required to isolate the analyzer sampling system from the sample gas stream.

!

CAUTION

You must take precautions against ESD (electrostatic discharge) damage while performing the following operations. Precautions include using a wrist strap working on a grounded work surface, and storing electronic assemblies in anti-static packaging.

!

CAUTION

!

WARNING

Always disconnect power and/or external power sources to the analyzer before opening any covers or doors on the analyzer to check on any components or to perform maintenance within the enclosures.

If it is necessary to open the analyzer’s covers or doors while the circuits are live, first monitor the area for flammable gases and proceed only when the area is safe.

Cleaning/Replacing Parts in the Sampling System

To clean and/or replace parts in the analyzer sampling system:

1. Manually zero the analyzer (“Flush/Zero” mode), isolate the analyzer sampling system from the sample gas stream, and power down the analyzer as described in this chapter.

2. Continue with the procedures to disassemble, clean or replace parts, and reassemble the appropriate sampling system components and all associated sample system tubing.


3. Restore power to the analyzer as described in procedures in this chapter.

4. Perform a leak (pressure) check on all sample system fittings that were disconnected/reconnected.

Other Maintenance

!

WARNING

If it is necessary to perform maintenance on the analyzer while the circuits are energized and with the Electronics Enclosure door open, first monitor the area for flammable gases and proceed only when the area is safe.

When the Electronics Enclosure is open, take appropriate precautions to avoid electrical shock. Hazardous voltages are present inside.

If a procedure for a certain maintenance task is not described in the analyzer User Manual, contact AMETEK Service Personnel for details about performing the required maintenance.

!

WARNING

When performing equipment maintenance in hazardous areas, all safety standards and procedures must be followed, as specified by the

Owner Company, local electrical-inspection authority, and National/

EU regulations.

Sample System Leakage Test

After performing any maintenance procedures such as replacement of parts or cleaning of the analyzer components, you must check the sample system to determine if any of the procedures has affected the integrity of the sample system.

!

CAUTION

The sample system should be charged with instrument air, sealed off, and checked after a period of time for a drop in pressure.

1. Turn off AC power.


2. Close both the sample inlet valve (FV1) and sample return valves

(FV2) located inside the oven.

3. Connect the external Utility port to a source of regulated instrument air set to 50 PSIG. Refer to Figure 3-13.

4. Open valve A to pressurize the system for at least 15 seconds. Record pressure displayed on “Test Gauge”.

5. Shut off Valve A and after a period of 15 minutes, record the pressure.

6. The pressure must not drop more than 1 PSIG over this time period.

OVEN

Demister

Test

Gauge

Valve A

50 PSIG

Instrument Air

Cal Gas Inlet

Sample

Return

RTD

Sample

Inlet

Demister

Vent

Figure 3-13. Sample System Leak Test




CONTROLLER/USER INTERFACE

Refer to 883056904 User Interface Manual for details on the AMEVision interface.

Controller/User Interface | 4-1


Controller/User Interface | 4-1

ALARMS

Alarm Relays

There are four (4) alarm relays maintained by the analyzer. All relays are failsafe; this means that an open contact indicates a problem.

• Relay 1 is dedicated as a System Alarm

• Relay 2 is dedicated as a Data Valid Alarm.

• Relays 3 and 4 are user-configurable.

System Alarm - Relay 1

Relay 1 is used to indicate a system alarm condition. A system alarm occurs when there is a condition that prevents the analyzer from making a measurement. When this happens, the relay contact opens and activates the alarm. Either Relay 3 and Relay 4 can also be configured optionally to trigger a system alarm condition. Refer to Appendix C for details on the operation of the analyzer state machine.

Data Valid Alarm - Relay 2

Relay 2 is used to indicate that the current concentration measurements and analog outputs are valid. If the data is NOT valid, the relay contact is open. Refer to Appendix C for details on the operation of the analyzer state machine.

Programmable Relays - Relay 3 and Relay 4

Relays 3 and 4 can be used to configure a selected parameter, its upper limit, and its lower limit. If the selected parameter is out of range, the corresponding relay contact opens and an alarm activates.

Relays 3 and 4 can optionally be configured as a system alarm. Refer to Chapter 4 in this manual for details.

Alarms | 5-1

Alarm Conditions and Responses

There are four alarm levels that indicate the severity of an alarm condition. These levels are 1 thru 4 with level 1 being the most serious condition.

• Level 1: Both the System Alarm and Data Valid relays are opened. The analyzer jumps into period 2, Not Ready, where the sample system is continuously flushed with air or nitrogen.

• Level 2: Both the System Alarm and Data Valid relays are opened. The analyzer does not jump into period 2, Not Ready.

• Level 3: Indicates a warning. No alarm relays change state and there will be visual indication at the local display and on the web page.

• Level 4: This is a user configurable alarm. Relay 3 or Relay 4 may change state. Refer to the 888 User Interface Manual for instructions on how to set up programmable relays.


Alarm Timer Stopped

Cell Temperature Alarm

Demister Temperature

Alarm

High Cell Pressure

Alarm

Cell RTD Failure

Demister RTD Failure

Flange RTD Failure

Heater RTD Failure

Heater OT Failure

Level 1 Alarms

The analyzer has an internal 1 second clock to time the state machine periods. This timer can be disabled via the service menu. The alarm will persist until the timer is enabled.

The cell temperature is below its lower limit. Low cell temperature may cause Sulfur mist to condense onto the optical surfaces.

The demister temperature is outside of its upper or lower limits. The demister target temperature is 129 °C. Sulfur mist will coalesce inside the demister and return to the process.

The cell pressure has exceeded its maximum value. A high cell pressure indicates a possible blockage in the sample path.

These alarms indicate that an RTD temperature sensor has failed.

Manifold Pressure

Alarm

Flange Temperature

Alarm

Low Light Alarm

Zero Error Alarm

Span Calibration Error

Cell Flow Alarm

The instrument air pressure is below the required pressure to operate system pneumatic valves.

The temperature at the input flange is low. This is a possible plug condition as Sulfur may build up inside the flange.

The light level at the four detectors has dropped below 50% of the limit. The alarm usually indicates that the optical surfaces have been seriously fouled and require cleaning.

Level 2 Alarms

The light levels measured during a zero calibration are outside the upper or lower limits. This error will automatically be cleared on a successful zero. The analyzer will use the zero values from the previous successful zero until the next successful zero calibration.

The calculated span value is outside its upper or lower limits.

This error will automatically be cleared on a successful zero.

The analyzer will use the span values from the previous successful span until the next successful span calibration.

This error indicates that the automatic flow control is unable to regulate cell flow. This occurs when the proportional valve is at its maximum or minimum limit.

Alarms | 5-3

Low Light Warning

Level 3 Alarms

The light level at the four detectors has dropped below acceptable levels. The alarm usually indicates that the optical surfaces have been fouled and require cleaning.

Detector Temperature Alarm

The filter block (part of 883048901) is maintained at 40 °C to increase the lifetime of the interference filters. This alarm is set if the temperature is out of its limits.

Flange Temperature Alarm

The temperature at the input flange is below its lower limit.

This is a indicates that there is a cold spot at the flange that may lead to a plugging condition.

High Flash Count Warning

The 888 varies the number of flashes for each detector to ensure adequate light levels at each photodiode. A high flash count usually indicates that optical surfaces need cleaning.

Low Flash Count Warning

The 888 requires a minimum number of flashes per measurement to perform a span calibration. The alarm is set if any flash count falls below 6.

Alarm Relay 3

Alarm Relay 4

Level 4 Alarms

A programmable alarm relay has exceeded its limits


TROUBLESHOOTING

Diagnostic Functions

The Model 888 includes a number of diagnostic functions that can be accessed through the user interface. Refer to the Diagnose menus in Chapter 4 of this manual for a more detailed description. These diagnostics can be used to test analog outputs, relay operation, solenoid valve operation, proportional valve operation, lamp functionality, and detector operation.

Diagnostics Mode

To use the diagnostic functions, the analyzer must be in diagnosticss mode. Diagnostics mode is enabled by moving the Enable Diagnostic slip switch on the appropriate screen to the “ YES ” position and pressing the

ENTER key. Once all diagnostic tests have been performed, normal operating mode can be restored manually by reversing the Enable Diagnostics process and moving the slip switch to the “NO” position.

Diagnostic mode automatically terminates if there are no keypad entries for the configured time period.

!

CAUTION

Do not open the enclosure door unless the area is known to be free of hazardous gasses. Units with purge controllers need to be programmed for Bypass mode as the analyzer must be powered.

!

CAUTION

There are hazardous voltages inside the electronics enclosure. Only a qualified technician should work on the analyzer while it is powered up.

Troubleshooting | 6-1

Problems and Possible Causes

Oven/Cell Temperature Not Reaching Setpoint

Ambient conditions and the analyzer’s T3 heater rating (maximum of

200 °C) can cause the cell to take more than an hour to reach temperature.

If the cell is not reaching its programmed setpoint, there are several possible causes. Use the Configure_Status menu to view the cell temperature and heater duty cycle. If the heater duty cycle is at 100% and the temperature is not increasing, use the following check list to resolve cell temperature not reaching or maintaining its target.

• Check for an open heater fuse.

There are three fuses located inside the electronic enclosure at locations 4, 5, and 6 on terminal block TB1. The heater fuse is TB1 Terminal 4.

• Check for a excessive flow through the aspirator located in the sample oven.

Excessive gas flow through the aspirator can cool down the oven.

Refer to the User Interface (Chapter 4) for the configuration of sample flow, Configure_Pressure_Aspirator.

The analyzer should be configured to produce 1 to 2 liters per minute through the sample cell.

• Check the active alarms for a RTD failure alarm.

An open or shorted RTD will be displayed as 999 °C on the Configure_Status menu.

Demister Temperature Not Reaching Setpoint

• Check the cell temperature to see if it is above 130 °C.

The demister setpoint is normally 129 °C. The Configure_Status menu can be used to view the cell temperature.

• Check demister operation.

Excessive instrument air flow can cool the oven. The demister is cooled by flushing itself with instrument air. The demister temperature will be below the oven temperature. If the demister duty cycle is above 75%, this could indicate a problem with the cooling air flow. The Configure_Status menu can be used to view the demister duty cycle.

• Check the active alarms for a RTD failure alarm.

An open or shorted RTD will be displayed as 999 °C on the Configure_Status menu.


Low Light Conditions

!

CAUTION

The Xenon Flash Lamp emits ultraviolet light. Never look directly into the lamp while it is flashing

A low light alarm indicates a possible issue with the Xenon Lamp or an obstruction in the optical pathway. An obstruction can be caused by deposits on the optical surfaces or by a mechanical misalignment.

The Xenon lamp flashes in bursts at a rate of 50 Hertz. A burst should occur at one second intervals. The number of flashes per burst is automatically set during a zero cycle.

Figure 6-1. Detector Flash at Zero

There is an audible “chirp” from the lamp during a burst of flashes. If there is too much ambient background noise, the lamp can be disconnected from the enclosure wall and its output can be confirmed visually. If the lamp is not flashing, this could indicate a problem with either the flash lamp assembly (403225901) or the lamp power supply (100-2061).

• Access the Configure_Calibration_Zero Calibration screen (Figure 6-1) on the user interface. The number of Flashes at Zero can be viewed for each detector. If the number of flashes exceeds 30 there are three possibilities.

- The Xenon lamp has degraded and the energy-per-flash has dropped.

(Typically a lamp will last in excess of three years.)

- An optical surface has been fouled sufficiently to block light.

- The lamp assembly, detector assembly, or mirror block is not secure and caused a misalignment of the optical system.


Cleaning the Optical Surface

To clean the optics use methanol as a solvent with lint free wipes and swabs. Take care not to leave fingerprints on the surfaces.

!

CAUTION

!

CAUTION

Do not dry wipe or clean device in potentially explosive atmosphere.

Use suitable clothing and shoes with respect to the danger of hazardous electrostatic charges.

!

CAUTION

Do not use rubber gloves or similar.

• Check that all optical surfaces are clean. Examine the optical surfaces for any cloudy deposits that will obscure the light from the lamp.

• Check the windows between the electronics and oven enclosures.

Carefully remove the detector assembly (883048901) and clean the lens.

!

WARNING

Hot surfaces are present in the oven enclosure.

• Check the two mirrors in the reflector box located inside the oven.

• Carefully remove the lamp assembly and check the lamp surface.

There is a focusing lens in the lamp assembly mounting collar as well.

Recommended Optical Surface Cleaning Instruction

All ooptical sutfaces wihin the 888 should be cleaned using a Kimwipe or similar optical grade cleaning sheet that has been wetted with acetone or isopropyl alcohol. the purity of the solvent should be technical grade or better.

!

WARNING

DO NOT USE LENS CLEANING WIPES, ie. individually wrapped wet napkins. THEY CAN CONTAIN CONTAMINANTS THAT

CAN ADVERSELY EFFECT THE PHOTOMETRIC MEASURE-

MENT.

When cleaning any optical surface hold the optics by the side or edges and take great care not to touch the optical surface with bare skin, work gloves, or other foreign materials. Using a pair of clean lab gloves is recommended whenever cleaning the optics. Only the optical grade clean-


ing sheet that has been wetted with acetone or isopropyl alcohol should make contact with any optical surface.

Ensure that no streaking has occured on the optical surface. This can be easily seen by rotating the cleaned optic and shining a light on it. If a residue is on the surface continue to clean the optic with a new wetted cleaning sheet until the surface is free from any streaks.

!

CAUTION

Take great care not to scratch or damage the optical surface when inserting the optic back into its original position.

Check the Optical Alignment

To check the optical alignment:

• Carefully loosen the detector mounting ring and remove the detector assembly.

• Hold a business card or equivalent to the opening from the oven.

There should be a bright white circle of light approximately 25 mm in diameter.

• Mount the detector and tighten the locking ring.

If there are still problems:

• In the electronics enclosure, check that the detector assembly

(883048901) and lamp assembly (403225901) are flush against their respective mounting collars and that their locking rings are tight.

• In the oven enclosure, check that all hardware securing the mirror block is tight.

!

WARNING

Hot surfaces are present in the oven enclosure.




PARTS REPLACEMENT

!

CAUTION

Do not open the enclosure door unless the area is known to be free of hazardous gases. Units with purge controllers need to be programmed for Bypass to power the electronics.

!

CAUTION

There are hazardous voltages inside the electronics enclosure. Only a qualified technician should work on the analyzer while it is powered up.

!

CAUTION

There are hot surfaces present in the oven enclosure. Allow the oven to cool to ambient temperature before touching components with bare hands. Protective Equipment (high temperature gloves) can be used.

!

CAUTION

Hazardous gas is present in the sample system. This applies to the oven enclosure only as there is no sample gas present in the electronics enclosure. H

2

S and SO

2

are present in the process gas. Gas monitors and protective equipment should always be used when working with the sample system.

!

CAUTION

Take precautions against electrostatic discharge when handling all circuit assemblies in the electronics enclosure. Use a grounded wrist strap and anti-static work surfaces.

Parts Replacement | 7-1

Parts

Description

Quartz Window, 1.5”

Window Teflon Gasket

Window O-Ring

Mirror

Mirror Teflon Gasket

Lamp Assembly

Demister Pad – Assembly

Fuse, Electronics, 1 Amp

Fuse, Heater, 4 Amp

Fuse, Main, 5 Amp

Varistor

Clock Battery

Sample Inlet Valve

Sample Return Valve

Sensor Assembly

Optics Detector Assembly

DC/DC Converter

Amevision Circuit Assy.

Lamp Power Supply

Keypad – SST

Color Display

Cable, Display

Signal Disconnect Assembly

Aspirator

Demister Assembly

RTD, Sample Cell

RTD, Flange

RTD, Demister

Pressure Transmitter

Solid State Relay

Proportional Valve

Manifold Valve 3-way

Ametek Part Number

200887001

880042001

202813026

273377002

883074002

403225901

883026904

◙

◙

◙

◙

◙

◙

Recommended Spare Part

◙

301-0860

301-0862

25780JE

203429001

301-0382

271446001

273383001

883047901

883005901

883049901

8000-122-SE

100-2061

273398001

1000-617-JE

1000-701-JE

883110901

407300902

883026901

883095001

883095002

273402001

273415001

273291001

883038901

301-0424

◙

◙

◙

◙

◙


24 Volt Power Supply

Heater (120 V models)

Heater( 230 V models)

Cell Assembly (High Range)

Cell Assembly (Low Range)

Temp. Signal Converter

Conax Gland Seal

273524001

883024901

883024902

883034902

883034901

273563001

200859002 ◙


Sample Cell

880042001

200887001

880042001

Figure 7-1 Sample Cell - 883034901 (Standard Range)


Mirror Block

883074002

880042001

Figure 7-2 Mirror Block - 883023902


Electronics Enclosure Interior

883047901 883048901

883038901

273415001

403225901

273291001 883049901 273524001

Figure 7-3 Electronics Enclosure Interio


301-0382

Figure 7-4. 8000-122 SE Circuit Assembly


LCD Display Detail

1000-617-JE

LCD Display

1000-701-JE

Display Cable

8000-122-SE

Figure 7-5. Display and Cable.


Keypad

Figure 7-6. Keypad - 273398001

273398001

Keypad


Sensor Board

Figure 7-7. Sensor Electronic Assembly - 883047901


Detector Board

Figure 7-8. Detector Board - 883048901


DC/DC Converter Assembly

Figure 7-9. DC/DC Converter Assembly - 883049901


Lamp Power Supply

Figure 7-10. Lamp Power Assembly - 100-2061


Signal Disconnect do not install TB5

RED

10cm LONG, 18awg

TWISTED TOGETHER.

STRIP ENDS 5mm.

Figure 7-11a & b- 888 Signal Disconnect- 883110901


Figure 7-11a & b- 888 Signal Disconnect- 883110901


Sample Oven Enclosure - Interior

883026901

Demister

407300902

Aspirator

271446001

Sample Inlet Valve

273383001

Sample Return Valve

Figure 7-12. Sample Oven Components

883024901 or 883024902

Heater (120 Vac or 240 Vac)


Manifold Block Detail

Figure 7-13. Pilot Valve Locations


Flange RTD

Figure 7-14. Flange Formed RTD - 883095002

Cell RTD

Figure 7-15. Sample Cell Formed RTD - 883095001

Demister RTD

Figure 7-16. Demister RTD - 273402001


Fuses

25780JE

5 Amp

Main

301-0862

4 Amp

Heater

301-0860

1 Amp

Electronics

TB1

1 2 3 4 5 6 7 8 9 10 11 12

203429001

Varistor

(3 plcs)

Figure 7-17. AC Terminals inside Electronics Enclosure


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WIRING DIAGRAMS

This appendix contains the wiring diagrams for all the standard and optional models of the Model 888 Tail Gas Analyzer.

Wiring Diagrams | Appendix A-1

Figure A-2. Power and

Signal Junction Box

Appendix A-2 | Model 888 ATEX IECEx Tail Gas Analyzer

Figure A-3. Wiring Diagram Zone 1














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H

2

S AND SO

2

CALCULATIONS

Concentration Measurement

There are four detectors and bandpass filters used to measure the concentration of H

2

S and SO

2

. The signal from each of the detectors is measured by individual analog-to-digital converters and those values are used to calculate concentration.

Absorbance Calculation

The absorbance is calculated for each channel using the stored values from the last zero calibration. The absorbance for each detector is calculated by the formula:

ABS = log

(

AD

zero

AD

measured

)

AD zero

AD measured

Stored analog-to-digital converter reading

Current value from the converter.

If span correction is enabled, each absorbance value is then multiplied by its corresponding span factor.

One of the four detector filters is at a wavelength not absorbed by either

H

2

S or SO

2

. That measurement is used as a reference for the subsequent calculations. The absorbance of the reference detector is subtracted from each of the remaining three detector absorbance values. A polynomial is applied to these differential absorbance values to calculate concentration.

There is a separate set of polynomial coefficients for H

2

S and SO

2

. The delta terms in the equation are the differences between a measurement absorbance and the reference absorbance.

Calculations | Appendix B-1

The concentrations are then corrected for differences in the cell temperature and pressure recorded at the time of factory calibration.

• Temperature correction scales concentration by the ratio of the current temperature and the factory calibration temperature.

• Pressure correction scales concentration by the ratio of the factory calibration pressure temperature and the current pressure.

Excess H

2

S, Excess SO

2

, Ratio (H

2

S/SO

2

) and Total (H

2

S + SO

2

)

Excess H

2

S is calculated by the following equation:

Excess H

2

S= [conc]

H2S

- Excess Factor * [conc]

SO2

The default value for the Excess factor is 2.0 and the concentrations of H

2 and SO

2

are in percent by volume.

S

Excess SO

2

is calculated by the following equation:

Excess SO

2

= [conc]

SO2

-

[ conc]

H2

S

Excess Factor

Ratio is calculated by the ratio of the H

2 the sum of the H

2

S and SO

2

S and SO

2

concentrations. Total is

concentrations.

Air Demand

The two-step modified Claus Process consists of a high temperature reaction step followed by a low temperature catalytic reaction. The two reactions, high temperature and catalyst, are shown below:

3 H

2

S + O

2

SO

2

+ 2 H

2

S + H

2

O

2 H

2

S + SO

2

S

X

+ 2 H

2

O

The Model 888 can provide an analog output that can be used to regulate the amount of air needed by the reaction furnace to produce the correct ratio of H

2

S to SO

2

.

The correct amount of process air can be estimated using the following equation:

∆ A ≈ Plant Factor ( 2[SO

2

] - [H

2

S] )

Appendix B-2 | Model 888 ATEX IECEx Tail Gas Analyzer

• If ∆A=0, the appropriate amount of air is entering the process.

• If ∆A< 0, there is insufficient air

• If ∆A> 0 there is excess air.

The plant factor in the equation is determined by the concentration of H

2 upstream of the Claus Process and the ratio of flows before and after the

S

Claus Process, i.e

Plant Factor =

Q t

[H

2

S] acid gas

Q acid gas

Air demand is defined as -∆A.

The equation implemented by the Model 888 is shown below:

Air Demand

%

= d {plant factor(Process ratio [SO

2

] - [H

2

S] ) - Excess Air}

The configuration parameters can be found in Chapter 4 in the Configure _Calibration_Special Values menu. These parameters are labeled as follows:

Delta: Set to ±1

If the end user control method is direct acting , this should be set to -1 (i.e. air flow should be increased if air demand

> 0).

If the control method is reverse acting set to +1 (i.e. air flow should be decreased if air demand > 0).

Plant Factor The default value is 3.5.

Process Ratio The desired ratio of H

2

S to SO

2

. The default value is 2.00.

Excess Air

Specified excess air for the process in percent (%). The default value is 0.0.

Calculations | Appendix B-3


Appendix B-4 | Model 888 ATEX IECEx Tail Gas Analyzer

ANALYZER TIMING

Timing States / Periods

The Model 888 uses a state machine of 14 states to control the operation of the analyzer. These fourteen states are referred to as “periods” in the user manual. Timers are responsible for many of the events that cause state transitions. The use of the term “period” is a carryover from the legacy

880NSL nomenclature.

Of the 14 states or periods, Periods 1 through 8 are common to all versions of the Model 888. Periods 9 through 11 apply only to analyzers with the steam blowback option. Periods 12 through 14 are special periods used for diagnostic purposes. Figure 1-8 is a summary of the 14 periods.

The timers associated with many of the periods can be modified using the Configure_Timers_Period Timer menu found in Chapter 4. All time entries are in seconds.

Period 1 – Special Flush

This is the initial period when power is applied to the Model 888. This period automatically transitions to Period 2 once the software finishes its initialization process.

Period 2 – Flush and Zero

The analyzer remains in Period 2 until the sample system has reached temperature and all system level alarms have cleared. During this time the sample cell is continuously flushed with instrument air to prevent any sulfur mist from the process solidifying and blocking flow in the oven.

Once all system alarms have been cleared, the Period 2 time will begin counting down.

Analyzer Timing | Appendix C-1

The analyzer performs a zero calibration at this time. It will also adjust the lamp flash count for each of the detectors during the zero process. At the end of Period 2, the detector readings are saved and the analyzer advances to Period 3. The data valid contact will be open.

If there is a system alarm during the normal operation of the analyzer (i.e.

Periods 3 through 11), the current period will transition back to Period 2 until the alarm condition is cleared.

Period 3 – Sample Flush

The analyzer flows process gas through the sample system. The timer ensures that the sample system is flushed with gas before advancing to

Period 4. The analog outputs are held at the last valid reading and the data valid contact will be open.

Period 4 – Measure

The analyzer remains in Period 4 indefinitely until a system alarm, zero, or calibration event occurs. The concentration readings are updated once per second. The data valid relay contact will be closed and analog outputs will be active.

Zero and Photo-Span Calibration

A zero or photo-span can be initiated either automatically or manually.

Manual initiation is accomplished either by using the local display or from the remote input.

A photo-span calibration sequence is always preceded by a zero calibration sequence.

Once time in Period 8 elapses, the period will continue either revert to

Period 3 or continue to Period 9.

Only analyzers equipped with the steam blowback option, can be configured to advance to Period 9.

Appendix C-2 | Model 888 ATEX IECEx Tail Gas Analyzer

Operation Sequences

Zero Calibration

Period 5 → Period 6 → Period 3

Photo-Span Calibration (not configured for steam blowback period)

Period 5 → Period 6 → Period 7 → Period 8 → Period 3

Photo-Span Calibration (configured for a steam blowback period)

Period 5 → Period 6 → Period 7 → Period 8 → Period 9 → Period 10 → Period

11 → Period 5

Period 5 – Flush and Zero

During Period 5, the sample system is flushed with instrument air and a zero calibration is performed. The analyzer will also adjust the lamp flash count for each of the detectors during the zero process. At the end of the period, the detector readings are saved and the analyzer advances to Period 6. The analog outputs will be held at the last value in Period 4 and the data valid contact will be open.

Period 6 – Track Zero

This is an intermediate state that is used to determine the next period.

• If only a zero calibration is required the next state will be Period 3.

• If a photo-span calibration is required, the next period will be Period 7.

Period 7– Photo-Span Calibration

The span procedure occurs during this period. The span factors are updated if an adjustment has been configured. The sample cell continues to be flushed with instrument air. The data valid contact will be open and the analog outputs held at the last valid value. Once the timer elapses, the analyzer advances to Period 8.


Period 8 – Track Photo-Span Calibration

This is an intermediate state that is used to determine the next period. The next period will normally be Period 3 unless a steam blowback has been triggered. In that event the next period will be Period 9.

Steam Blowback

Analyzers equipped with the steam blowback option will force steam through the demister to eliminate the build-up of salts. A steam blowback can be initiated manually or configured to occur after a programmed number of photo-span calibration cycles. The data valid contact will be open and the analog outputs held at their last valid value during Periods 9 through 11.

Period 9 – Pre-Steam Flush

Instrument air is flushed through the sample cell during this period. The analyzer advances to Period 10 once the timer elapses.

Period 10 – Steam Blowback

Steam is directed through the demister and back into the process. During this time the sample cell is isolated to prevent any contamination. The analyzer will advance to Period 10 once the timer elapses.

Period 11 – Post Steam Flush

The sample system is flushed by instrument air during this period. The analyzer reverts to Period 5 once the timer elapses.

Special Periods

There are three special periods (12, 13, and 14) used for troubleshooting.

The data valid contact will be open and the analog outputs held at their last valid value during Periods 12 through 14.

Period 12 – Continuous Flush

The sample system is continuously flushed by instrument air during this period.


Period 13– Continuous Hold

All solenoid valves are de-energized during this period.

Period 14 – Continuous Sample

Process gas is continuously flowed through the sample cell during this period.

Manual Operation

Set Modbus register 273 (Manual Operation) for the following values to perform manual operation:

MANUAL IDLE = 0,

MANUAL ZERO = 1,

MANUAL CAL = 2,

MANUAL BLOWBACK = 3,

MANUAL MEASURE = 4,

MANUAL PERIOD1 = 10,













MANUAL PERIOD14 = 23


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PARAMETER IDS / MODBUS ADDRESSES

Parameter IDs & Modbus Addresses | Appendix D-1

Appendix D-2 | Model 888 ATEX IECEx Tail Gas Analyzer





ALARMS

Alarm Severity

Level 1 Alarms

This is the highest level or severity of alarm. A Level 1 alarm indicates either a hardware failure or a system error that prevents the analyzer from making a valid H

2

S or SO

2

concentration measurement. The analyzer needs immediate attention to correct the cause of the alarm before normal operation can resume.

A Level 1 alarm opens the System Alarm and Data Valid contacts. The state machine jumps to the Not Ready state (Period 2) and the period timer is stopped until the alarm condition is cleared.

Hardware Alarms

Hardware alarms indicate a component failure. A part may need to be replaced in order to correct the problem. Hardware alarms include:

• Defective Sample Cell Temperature Sensor (RTD)

• Defective Demister Temperature Sensor (RTD)

• Defective Flange Temperature Sensor (RTD)

• Defective Oven Heater Temperature Sensor (RTD)

• Defective Oven Heater Over-temperature Sensor (RTD)

• Defective EEPROM

• Loss of communications between the sensor (883047901) and detector

(883048901) assemblies.

Alarms | Appendix E-1

Operational Alarms

Op[erational alarms indicate a condition that prevents normal analyzer operation. The condition may or may not require user intervention to clear the problem. Operational alarms include:

• Low Light Intensity on a detector channel

• Sample Cell Temperature is outside the minimum/maximum values

• Demister Cell Temperature is outside the minimum/maximum values

• Sample Flow is outside the minimum/maximum values

• Excessive Sample Cell Pressure indicating a possible probe blockage

• Manifold Pressure is too low: pneumatic valves may not be operating properly.

Level 2 Alarms

A Level 2 alarm condition indicates a serious problem with the analyzer.

The analyzer responds by opening both the system alarm and data valid alarms. The state machine, however, does not jump to the Not Ready state. A Level 2 alarm condition can occur when there is a failed zero or span calibration cycle or if a service technician stops the period timer.

Level 2 alarms include:

• Period Timer stopped

• Span calibration factor is outside the minimum/maximum values

• Zero calibration failure

Level 3 Alarms

A Level 3 alarm condition is a warning that a more serious problem is imminent. There is a visual warning on both the local and remote displays.

The operator should take action to prevent the problem from becoming a

Level 1 or Level 2 alarm. Level 3 alarms include:

• Excessive Flash Warning indicating that the light intensity is dropping

• Low Flange Temperature warning indicating the possibility of a blockage

• Detector Temperature alarm indicating that the accuracy of the concentration measurements may be affected.

E-2 | Model 888 ATEX IECEx Tail Gas Analyzer

Level 4 Alarms

A Level 4 alarm is a programmable alarm. There are two programmable alarms provided. These alarms can be mapped to a parameter via the local display interface. Alarm operation can be selected to be normally open or normally closed.




Alarm Specifics

The twenty-three (23) alarm conditions are detailed in this section. Note that additional alarms can be added to the system in the future.

Alarm Timer Stopped [1]

The Period timer can be stopped to troubleshoot the analyzer. For example, if necessary, the analyzer can be made to continually flush the sample cell. If the timer were to be active the state machine would continue to function and return to the Measurement state (Period 4). A Level 2 alarm occurs as a reminder that the analyzer is not operating normally.

Restarting the timer clears the alarm condition.

Cell Temperature Alarm [2]

There is a temperature sensor mounted on the sample cell in the oven compartment. The temperature of that cell must be controlled to within the configured deviation. Typically the target temperature is 150 ± 5 °C.

If the temperature is outside the allowable range, a Level 1 alarm occurs.

This is a potentially serious condition as it could allow sulfur to build up on the optical surfaces.

The alarm condition will clear itself once the temperature is within range.

If the cell doesn’t reach temperature, there could be a problem with the heater, over-temperature detection, or excessive gas flow through the sample system. Note that excessive gas flow can conduct heat from the oven.

Low Light Alarm [3]

The Model 888 analyzer adjusts light intensity automatically by changing the number of lamp flashes per second. If the optical surfaces slowly become fouled, the number of flashes per second is increased to maintain light intensity on the detectors. Once the flash rate reaches 50, it is no longer possible to make a concentration measurement every second. This is a Level 2 alarm condition.

User intervention is required to increase the light intensity at the detectors. Possible corrective actions include cleaning the sample cell windows, and the mirrors in the reflector block, and to check the lamp operation.


Zero Error [4]

The analyzer periodically flushes the cell with air or nitrogen. During this time, the analyzer will record the light intensities for each of the four detectors. The light intensities are checked against a configurable minimum and maximum value. If the value is outside of these limits, the zero calibration fails and the analyzer continues to use the results from the last successful zero cycle. A Level 2 alarm occurs to notify the user that a zero cycle has failed. There are a number of possible causes for a failure. The sample cell may not have been completely flushed out or there may be a contamination problem with the optics.

The alarm condition is cleared upon the successful completion of a zero cycle.

Calibration Error [5]

The analyzer periodically performs a calibration check. This check can be done manually by insertion of a neutral density filter or done automatically by the software. During an automatic calibration, the number of flashes varies and the change in absorbance is compared to the theoretical absorbance.

For both methods, the ratio between the expected and actual values must fall between a programmable range (15% by default). If the ratio is outside this range, a Level 2 alarm results. Failure could be the result of a number of issues—a defective lamp or lamp power supply (100-2061) could cause the intensity per lamp flash to vary.

The alarm condition is cleared upon the successful completion of a calibration cycle.

Demister Temperature Alarm [6]

There is a temperature sensor mounted on the demister assembly in the oven compartment. The temperature of that cell must be controlled to within the configured deviation. Typically the target temperature is 129 ±

5 °C. If the temperature is outside the allowable range, a Level 1 alarm occurs. The demister removes sulfur mist from the process gas and returns it to the process pipe. The internal surfaces of the demister are controlled to a temperature that allows sulfur mist to condense into liquid sulfur thus removing it from the sample gas. Causes for this condition could be a defective solid state relay or excessive cooling air flow.

The alarm will clear itself once the temperature is in range.


Cell Flow Alarm [7]

The Model 888 analyzers regulate sample flow by adjusting a proportional valve in the aspirator drive air. Ideally, the sample flow rate is approximately 1.5 SLPM. If the proportional valve reaches its maximum or minimum control range and the flow is incorrect, a Level 2 alarm occurs. This problem can be caused by insufficient pressure at the valve inlet. The aspirator regulator gauge should be manually adjusted to achieve approximately 5 PSI above the process pipe pressure. Other possibilities are a defective valve or control electronics.

The alarm will clear once the proportional valve is within the limits of operation or the flow control is put into manual mode.

Flush Pressure [8]

The cell pressure is monitored to detect a possible blockage in the sample gas path. If gas is unable to flow through the sample cell, the pressure in the cell will increase becuase there is a restriction in the return path to the process pipe. A Level 1 alarm occurs if this is the case.

The alarm will clear itself once the cell pressure is reduced. Make sure that all manual valves in the oven are fully in the open position.

EEPROM Corrupt [9]

All configuration parameters are kept in non-volatile memory. This memory is known as EEPROM which is an abbreviation for Electrically Erasable Programmable Read-Only Memory. If the software detects a problem with this memory, configuration parameters may be corrupted. This condition triggers a Level 1 alarm.

This problem will not clear itself. The EEPROM can be reloaded through the local display. Should this fail, the memory device itself is defective and the assembly (883047901) must be replaced.

Note that the factory configuration is kept on an AMETEK server.

After reloading the configuration into the EEPROM, recycle power to clear the error.


Cell RTD Defective [10]

The software monitors the condition of the Resistive Temperature Detector (RTD) that monitors cell temperature. If the device fails, a Level 1 alarm occurs. The RTD could be defective or one of the three RTD wires may have been disconnected.

User intervention is needed to clear the alarm condition.

Demister RTD Defective [11]

The software monitors the condition of the Resistive Temperature Detector (RTD) that monitors demister temperature. If the device fails, a Level 1 alarm is asserted.

User intervention is needed to clear the alarm condition. The RTD could be defective or one of the three RTD wires may have been disconnected.

Flange RTD Defective [12]

The software monitors the condition of the Resistive Temperature Detector (RTD) that monitors the temperature of the mounting flange. If the device fails, a Level 2 alarm occurs because the analyzer is still capable of making concentration measurements. However, flange temperature cannot be monitored until the RTD is repaired.


Oven Heater RTD Open [13]

The software monitors the condition of the Resistive Temperature Detector (RTD) that monitors heater temperature in the oven. If the device fails, a Level 1 alarm occurs. This is a safety issue as the heater cannot be allowed to exceed 200 °C and reach the auto-ignition temperature of process gas. There are two redundant sensors in the heater.



Oven Heater Over-Temperature RTD Open [14]

The software monitors the condition of the Resistive Temperature Detector (RTD) that monitors heater temperature in the oven. If the device fails, a Level 1 alarm occurs. This is a safety issue as the heater cannot be allowed to exceed 200 °C and reach the auto-ignition temperature of process gas. There are two redundant sensors in the heater.


Manifold Pressure Alarm [15]

The Model 888 analyzer uses pneumatic control valves. The software monitors the manifold pressure for these valves. The manifold pressure alarm occurs if the pressure drops below the minimum operating pressure for the valves. This alarm is a Level 1 alarm.

User intervention is needed to increase the manifold pressure above the minimum limit. Adjust the pressure regulator on the manifold assembly.

Make sure there is a nitrogen or air supply as required in the manual.

Detector Temperature Alarm [16]

The detector assembly (883048901) includes a heated optical filter block. It is maintained at a constant 40 °C. The filters are kept at an elevated temperature to avoid humidity from compromising the filters. A Level 2 alarm condition occurs if the temperature is out of the allowed range.

This alarm may indicate that the ambient temperature has exceeded 40 °C.

The detector assembly may need to be replaced if the ambient temperature is not above 40 °C and an alarm exists.

The analyzer will continue to operate normally if this alarm occurs.

Flange Temperature Alarm [17]

There is a temperature sensor mounted to the pipe flange on the oven enclosure. If the temperature of the flange drops below the alarm set point, there is a danger that sulfur deposits will occur within the probe. If left unchecked, this will lead to a blockage. This is a Level 1 alarm.

This alarm is cleared by raising the temperature of the flange. Check the insulation around the external ball valve and make sure there is sufficient heat applied to the ball valve.


Detector Communications Failure [18]

The detector assembly (883048901) communicates to the sensor assembly,

(883047901). If this communication link is broken, concentration measurements cannot be made. This is a Level 2 alarm.

User intervention is required. Make sure that all cables are fully inserted. The sensor assembly may be defective.

High Flash Count Warning [19]

The Model 888 analyzer adjusts the number of flashes-per-second to achieve adequate light intensity at the detector. If the optical system is fouled, the required flash count will increase. If a flash rate is within 10 flashes of the maximum, a

Level 3 alarm occurs. This alerts the end user to a potentially more serious problem leading to a Low Light Alarm.

Refer to the Low Light Alarm for possible causes of this condition.

Low Flash Count Warning [20]

The calibration period requires a minimum number of flashes. The flash count will be checked during a calibration. If the light intensity is too high or the target

ADC value (set by Parameter 207) is too low, then there is a problem. The software will attempt to alter the target value to achieve the minimum flash count.

The alarm will clear itself if the flash count is adequate (during the next cal period).

User Alarm (Relay 3 and 4) [21] [22]

This is a Level 4 alarm to log any programmable alarms.

Flange Temperature Warning [23]

There is a temperature sensor mounted to the pipe flange on the oven enclosure.

If the temperature of the flange drops below the alarm set point, there is a danger that sulfur deposits will occur within the probe. If left unchecked, this may lead to a blockage. This is a Level 3 alarm.

This alarm is cleared by raising the temperature of the flange. Check the insulation around the external ball valve and make sure there is sufficient heat applied to the ball valve.


No results