Twin City Air Kit Fans - ES-56 - Manual

Kit Concept
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 struc-
ture. 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 responsi-
bility of the purchaser.
Housing stiffeners or frame should provide rigidity and
support to the housing. Adequate rigidity can be pro-
vided 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
so that the housing inlets will be centered with the
wheel when hot. Connecting ductwork should have inde-
pendent 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 vibra-
tion. 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 turn-
downs, the bearing supports should be removable to
allow for installation of the recess cone.
Air Kit Assembly and Installation
Components are assembled in order shown in Figure 1.
Since requirements vary, the purchaser assumes re-
sponsibility 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
Note 5
Bearing
Components
Socket Head
Capscrew
Shaft
A
A
Section A-A
Opposite Side
Air Kit Housing
For Forward
Curved DWDI Unit
Shaft
Inlet Funnel
Air Kit Straightening Vanes
Air Kit Recess Cone
Shaft Seal
Shaft Cooler Guard
Drive Bearing (Fixed)
Opposite Bearing Expansion
Type (See Insert)
Drive Sheave
Bearing Pedestal
(Supplied By Others)
Shaft Cooler
Typical Oven Type Installation.
Spacer Ring and Insulated
Wall Supplied By Others.
Support (or Stiffener or Frame)
Angles Required For Proper
Support of Housing. Supplied By
Others.
Removable Cut-off.
Drill Holes At Base
of Cut-off to Match
Holes in Scroll and
Mount With Bolts.
Cut-off
Mounting
Holes
Air Kit Forward Curve
Centrifugal Type Wheel
Rotation
Shaft Expansion Modification (Typical)
Figure 1. General Assembly of Twin City Fan & Blower Air Kit
Notes:
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 compo-
nents for special application. Consult factory for
details.
5. One inch for thermal expansion typical.
ES-56
June 1998
Air Kit Fans
INSTALLATION, OPERATION & MAINTENANCE MANUAL