Air Kit Fans - ES-56

Air Kit Fans - ES-56
Air Kit Fans
June 1998
Kit Concept
so that the housing inlets will be centered with the
wheel when hot. Connecting ductwork should have independent supports and have expansion joints or other
allowance for thermal expansion.
Bearing supports should be rigid enough to support
static and dynamic loads caused by belt pull and vibration. The bearing mounting surface should be flat and
square with the shaft axis centerline so that the bearings
are not subjected to loads from mounting misalignment.
The supports should be free from thermal effects which
can cause misalignment of bearings and designed so
that the bearing is not heated by conduction through
the pedestal or convection through the airstream. When
recess cones are combined with shafts having turndowns, the bearing supports should be removable to
allow for installation of the recess cone.
Air kits (or fan kits) are sold as sets of components such
as wheels, housings, shafts, bearings, shaft coolers,
cooler guards, recess cones, straightening vanes and
shaft seals. Kits are installed and assembled by the
purchaser in a plenum or oven. The wheel (or wheels)
are supported on a shaft between two bearings.
The term “twin” is used to designate two wheels on
a common shaft. Spacing of the housings and wheels
in the plenum is done so that the inlet restriction is the
same on all inlets. More information about performance
and configuration specifics may be found in Bulletin 150.
Support Structure
Air kits are normally installed as part of another structure. These structures must be designed to withstand
both static and dynamic loading. The structural design
should follow the same guidelines for foundations and
supporting structures as found in ES-52. Proper design
of supports and supporting structures are the responsibility of the purchaser.
Housing stiffeners or frame should provide rigidity and
support to the housing. Adequate rigidity can be provided by positioning bracing as shown in Figure 1.
Additional support may also be required. Supports
should not block the inlet or discharge of the fan. For
oven type applications the supports must be designed
Air Kit Assembly and Installation
Components are assembled in order shown in Figure 1.
Since requirements vary, the purchaser assumes responsibility for the proper installation and operation of
the unit.
Assembly Preparation
Housings are mounted so that the inlets are equally
constricted. For twin fans, this means one-quarter of the
total clearance is at the outer fan inlets and one-half of
the total clearance is in the middle. Bearing pedestals
Figure 1. General Assembly of Twin City Fan & Blower Air Kit
Socket Head
Air Kit Forward Curve
Centrifugal Type Wheel
Note 5
Opposite Side
Section A-A
Air Kit Housing
For Forward
Curved DWDI Unit
Shaft Expansion Modification (Typical)
1. Air kit components available separately or in almost
any combination.
2. Inlet funnel is formed as part of housing side on
some sizes.
3. Bearing pedestal must be designed to support
dynamic loads (supplied by others).
4. A variety of materials are available for many components for special application. Consult factory for
5. One inch for thermal expansion typical.
Inlet Funnel
Air Kit Straightening Vanes
Air Kit Recess Cone
Shaft Cooler Guard
Drive Bearing (Fixed)
Opposite Bearing Expansion
Type (See Insert)
Shaft Seal
Drive Sheave
Shaft Cooler
Bearing Pedestal
(Supplied By Others)
Support (or Stiffener or Frame)
Angles Required For Proper
Support of Housing. Supplied By
Typical Oven Type Installation.
Spacer Ring and Insulated
Wall Supplied By Others.
Removable Cut-off.
Drill Holes At Base
of Cut-off to Match
Holes in Scroll and
Mount With Bolts.
are installed so that the bearings can be shimmed for
proper centerline height.
Provide for passage of shaft through the wall of the
oven. Relief must be provided for recess cone mounting
and shaft seal (see Figure 1). Installation of a recess
cone may also require the use of a cylindrical section
to restrain insulation and maintain proper depth of oven
Clean the wheel bore with solvent and check for
burrs, rust paint, or other obstruction. Use 80 grit emery
cloth by hand to remove foreign particles. Flush any grit
remaining and wipe clean. Place an even film of oil in
the wheel bore.
Extra care should be taken with shafting. Shafts for
air kits tend to be quite long and heavy and can be
easily damaged. Clean the shaft with solvent and check
for nicks, scratches, and burrs. Remove rough spots
with emery cloth and clean again. Cover the shaft with
a light film of oil.
Fan housing and bearing supports are installed as previously described. Inlet funnels which may have been
supplied separately should be mounted to the housing
at this time.
1. Place wheel into housing through discharge of housing. Check wheel for proper wheel rotation before
proceeding (see Figure 1). Block wheel so that
wheel inlets are centered with housing inlets.
2. Insert the shaft through housing inlet and wheel
bore. Kits which have the shaft extension modification will have keyways at both ends of the shaft.
Identify the drive end from fan drawings to insure
proper shaft orientation. Temporarily support the
shaft and wheel assembly on blocks across the full
length of wheel. Do not support on housing sides,
inlet funnels, wheel end rings, or accessories.
3. The optional accessories are installed in this order
onto the shaft: recess cone, shaft seal, shaft cooler,
and cooler guard. These parts are installed outside
the oven wall except the recess cone, which
becomes part of the wall. All fasteners should
remain loose until bearing mounting is complete.
4. Slip the bearings onto the shaft and pedestal and
secure, making sure the following instructions are
a.Mounting expansion bearings — no shaft expansion modification.
(1)Place bearing onto the shaft with bearing collar facing away from wheel.
(2)Adjust expansion capability of bearing so that
the bearing is toward the wheel in the bearing
housing. (When the shaft expands from heat,
the bearing will be pushed away from wheel
in the bearing housing.)
(3)With bearing properly aligned and shaft at the
required centerline height, bolt bearing to the
pedestal. Go to step 4c.
b.Mounting bearing with shaft expansion modification:
end of the shaft. The head of the inverted
socket head capscrew will fit in the short
keyway. Make sure that the shaft can expand
without the end of the keyway hitting the
screw head.
(2)With shaft at the proper centerline height and
bearing square with the shaft, bolt bearing
into position.
c.Tighten all setscrews remaining in bearings. (If
shaft expansion modification was used, do not
use any other setscrews on expansion side bearing other than the inverted screw provided.)
5. Position wheel in housing so that it will be centered
when hot. Shaft expansion must be allowed for high
temperature applications. The wheel will move away
from the drive (or fixed) bearing by an amount equal
to the distance to the wheel from the drive bearing
times the temperature rise times the coefficient of
thermal expansion — about 0.0000067/°F/inch for
steel. Tighten Allen-head
setscrews. (Allen-head
setscrews are normally provided.)
6. Accessories may now be permanently mounted and
bolted into position (recess cone, shaft seal, shaft
cooler and cooler guard). Rotate shaft manually to
insure adequate clearance.
7. Assemble drives as listed in ES-52.
8. Install cut-off in discharge of housing with bolts
through sides and base of cut-off.
9. Check and tighten all screws, nuts and bolts.
10. The installer may need to fine-tune balance the final
assembly. (All wheels are factory balanced. Low
speed FC units will generally not require a final
Maintenance of Kit Fan
See Bulletin ES-52 for normal maintenance instructions
for bearings, drives, etc. High temperature applications
should avoid heat soaking of shaft. Stationary (nonrotating) shafting should never be exposed to elevated temperatures or bending may occur. Shaft should always
be rotating in an elevated temperature environment.
On high-temperature applications, check all fasteners
(nuts, bolts, screws, and rivets) for tightness. Cyclic
heating and cooling can loosen fasteners from thermal
expansion and contraction. Check after the first few
cycles of thermal change or 48 hours, whichever comes
first. Then check on a monthly basis.
Performance Troubleshooting
See troubleshooting section of Bulletin ES-52 to identify causes of problems normally encountered. In addition to those mentioned, on kit type installations check
1.Vibration — Bent shaft caused by exposure of shaft
to high temperatures while not rotating.
2.Fan will not start or motor trips out after start-up
— Motor was not sized for WR2 required. Motor
horsepower too low for cold start.
(1)Slide bearing onto shaft with bearing collar
pointed away from the wheel and toward the
Twin city fan & blower |
5959 Trenton Lane N | Minneapolis, MN 55442 | Phone: 763-551-7600 | Fax: 763-551-7601
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF