Mass Flow Controller (MFC) for Gases

8711
Mass Flow Controller (MFC)
for Gases
• Direct flow measurement with
CMOSens®- Technology for nominal flow rates
from 20 mlN/min to 80 lN/min (N2)
• High accuracy and reproducibility
• Fast settling time
Type 8711 can be combined with...
• Optional fieldbus
Type 1150
Type 0330
Type 6013
Type 6606
MFC
Multi-channel
program controller
3/2 or 2/2-way
solenoid valve
2/2-way
solenoid valve
2/2 or 3/2-way
solenoid valve
Communications
Software
Type 8711 controls the mass flow of gases that is relevant for most applications in process technology. The measured value provided by the sensor
(see the description on page 2) will be compared in the digital control electronics with the predefined set point according to the signal; if a control
difference is present, the control value output to the proportional valve will
be modified using a PI-control algorithm. Due to the fact that the sensor is
directly in the bypass channel a very fast settling time of the MFC is reached.
In this way, the mass flow can be maintained at a fixed value or a predefined
profile can be followed, regardless of pressure variations or other changes in
the system. Type 8711 can optionally be calibrated for two different gases,
the user is able to switch between these two gases. As the control element,
a proportional valve working at low friction guarantees a high sensitivity and a
good control characteristics of the unit. Typical application areas are gas
dosing or rather the production of gas mixtures in:
•
•
•
•
•
•
Test benches,
Bio reactors,
Heat treatment,
Material coating,
Burner controls and
Fuel cell technology
Technical data
Full scale ranges1)
(Qnom)
Operating Media
20 mlN/min to 80 lN/min (N2),
please see table on page 2
Neutral, non-contaminated gases,
others on request
Max. operating pressure 10 bar (145 psi)
depending on the orifice of the valve
(at inlet)
Operating gas or air with conversion factor
Calibration medium
-10 to +70°C
Medium temperature
-10 to +50°C
Ambient temperature
±0.8% o.R. ±0.3% FS
Accuracy
(after 1 min. warm up time)
±0.1% FS
Linearity
±0.1% FS
Repeatability
1:50, higher control range on request
Control range
< 300 ms
Settling time (t95%)
Aluminium or stainless steel
Body material
Electr. housing material PC (Polycarbonate), optional metal
FKM, EPDM, others on request
Sealing material
NPT 1/4, G 1/4, screw-in fitting or flange,
Port connections
others on request
Valve is closed when power is off
Control valve
0.05 to 4.0 mm
valve orifices
0.00006 to 0.32 m3/h
kvs-values
Sub-D plug, 15-pin
Electr. connection
M12 5-pin for fieldbus
24V DC
Power supply
1)
Voltage tolerance
Residual ripple
Power consumption
Set point
Feed impedance
Output signal
Max. current (volt. output)
Max. load (current output)
Digital communication
Protection class
Dimensions [mm]
(without fitting)
Total weight
Mounting position
Light emitting diode display
±10%
< 2%
Max. 3.5 - 14 W
(depending on proportional valve used)
0-5 V, 0-10 V, 0-20 mA or 4-20 mA
> 20 kΩ (voltage),
< 300 Ω (current)
0-5 V, 0-10 V, 0-20 mA or 4-20 mA
10 mA
600 Ω
PROFIBUS-DP, DeviceNet, CANopen, RS232
or RS485 (RS interface only with Adapter)
IP40
See drawings
ca. 500 g (aluminium body)
Horizontal or vertical
Indication for Power, Limit (with analog signals) /
Communication (with fieldbus), Error
(default, other allocations possible)
Two
Binary input
(default, other allocations programmable) 1. start autotune
2. not assigned
One relay-output
Binary output
(default, other allocations programmable) 1. Limit (setpoint not reached)
Load capacity: 25V, 1A, 25VA
at standard conditions 1.013 bar (a) and 0ºC
www.burkert.com
p. 1/6
8711
Measurement principle
The actual flow rate is detected by a sensor. This operates according to a thermal
principle which has the advantage of delivering the mass flow without any corrections for the required pressure or temperature.
A small part of the total gas stream is diverted into a small, specifically designed
bypass channel, that ensures laminar flow conditions. The sensor element is a chip
immersed into the wall of this channel. The chip, produced in CMOS technology,
contains a heating resistor and two temperature sensors (thermopiles) which are
arranged symmetrically upstream and downstream of the heater. The differential
voltage of the thermopiles is a measure of the mass flow rate passing this bypass
channel. The calibration procedure effectuates a unique assignment of the sensor
signal to the total flow rate passing the device.
Gas
Min. QNom
[Nl/min]
Max. QNom
[Nl/min]
Acetylene
Argon
Helium
Carbon dioxide
Air
Methane
Propane
Oxygen
Nitrogen
Hydrogen
0.02
0.05
0.2
0.06
0.02
0.03
0.01
0.02
0.02
0.2
40
80
500
40
80
80
20
80
80
500
Notes regarding the selection of the unit
For the proper choice of the actuator orifice within the MFC, not only the
required maximum flow rate Qnom, but also the pressure values directly
before and after the MFC (p1, p2) at this flow rate Qnom should be known.
In general, these pressures are not the same as the overall inlet and
outlet pressures of the whole plant, because usually there are additional
flow resistors (tubing, additional shut-off valves, nozzles etc.) present both
before and after the controller.
Please use the request for quotation form on p. 4 to indicate the
pressures directly before and after the MFC. If these should be unknown
or not accessible to a measurement, estimates are to be made by taking
into account the approximate pressure drops over the flow resistors before and after the MFC, respectively, at a flow rate of Qnom.
In addition, please quote the maximum inlet pressure p1max to be encountered. This data is needed to make sure the actuator is able to provide a
close-tight function within all the specified modes of operation.
The request form on page 5 contains the relevant fluid specification. Using the experience of Bürkert engineers already in the
design phase provide us with a copy of the request containing the necessary data together with your inquiry or order.
Ordering table for accessories (connectors are not included in the delivery)
Article
Item no.
15-pin electrical connection
Sub-D socket 15-pin solder connection
918 274
Sub-D hood for Sub-D socket, with screw locking
918 408
Sub-D socket 15-pin with 5m cable, ass. on one side
787 737
Sub-D socket 15-pin with 10m cable, ass. on one side
787 738
PROFIBUS DP
M12 plug
918 198
M12 socket
918 447
PROFIBUS T-Connector
902 098
Adapter
RS232 adapter
654 748
RS485 adapter
654 538
2m PC extension cable for RS232 9-pin socket/plug
917 039
USB adapter
MassFlowCommunicator Communication software
670 639
Download at www.burkert.com
p. 2/6
8711
Pin Assignment
Sub-D plug, 15-pin
Pin
Connection
1
relay, NC contact
2
relay, NO contact
3
relay - middle contact
4
GND 24V-supply and binary inputs
5
supply +24V
6
8V output (only internal company use)
7
set-value input GND
8
set-value input +
9
actual value output GND
10
actual value output +
11
DGND (for RS232)
12
binary input 1
13
binary input 2
14
RS232 RxD (without driver)
15
RS232 TxD (without driver)
Fieldbus version
PROFIBUS DP – B-coded, M12 socket
(DPV1 max. 12 MBaud)
Pin
Connection
1
VDD
2
RxD/ TxD – N (A-circuit)
3
DGND
4
RxD/ TxD – P (B-circuit)
5
not configured
DeviceNet, CANopen – plug M12
Pin
Connection
1
Shield
2
not configured
3
DGND
4
CAN_H
5
CAN_L
p. 3/6
8711
Dimensions [mm]
Standard version
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Size A
G 1/4
NPT 1/4
p. 4/6
8711
Dimensions [mm]
Sub-base version
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Version with external valve
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Size A
G1/4
NPT 1/4
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p. 5/6
8711
Note
MFC/MFM applications - request for quotation
Please fill out and send to your nearest Bürkert sales centre* together with your inquiry or order
Company
Contact person
Customer No.
Department
Address
Tel./Fax
Postcode/Town
E-mail
MFC-application
MFM-application
Quantity
fill out
You can
directly
s
ld
fie
the
file
F
D
P
in the
nting
before pri
rm.
out the fo
Required delivery date
Medium data
Type of gas (or gas proportion in mixtures)
Density [kg/m3]
1)
ºC
Medium temperature [ºC or ºF]
ºF
3
Moisture content [g/m ]
no
Abrasive components / solid particles
yes as follows
Fluidic data
Maximum flow Qnom
lN/min 1)
3
mN /h
cmN3/min 1)
1)
cmS3/min (sccm) 2)
lS/min (slpm) 2)
kg/h
Minimum flow Qmin
lN/min
1)
mN3/h 1)
cmS3/min (sccm) 2)
kg/h
lS/min (slpm) 2)
Max. inlet pressure p1max
•
•
barg •
Pipe run (external-Ø)
metric, mm
Inlet pressure at Qnom
p 1=
barg
Outlet pressure at Qnom
p 2=
barg
MFC/MFM-port connection
cmN3/min 1)
imperial, inch
without screw-in fitting
1/4” without screw-in fitting (DIN ISO 228/1)
1/4” NPT-thread (ANSI B1.2)
with screw-in fitting
sub-base version
Installation
horizontal, valve upright (Standard)
horizontal, valve reclined
vertical, flow from above
vertical, flow from below
Ambient temperature
ºC
Material data
Body material
Aluminium
Stainless steel
Seal material
FKM
EPDM
other:
Electrical data
with standard signal
with fieldbus
output
input
0-5 V
0-5 V
PROFIBUS-DP
0-10 V
0-10 V
DeviceNet
0-20 mA
0-20 mA
CANopen
4-20 mA
4-20 mA
Please quote all pressure values as overpressures with respect to atmospheric pressure [barg]
Output/input signal
•
1) at: 1.013 bar(a) and 0ºC
2) at: 1.013 bar(a) and 20ºC
To find your nearest Bürkert facility, click on the orange box J
In case of special application conditions,
please consult for advice.
www.burkert.com
Subject to alterations
© Christian Bürkert GmbH & Co. KG
reset form
0905/5_EU-en_00891904
p. 6/6
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