Page 181 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Positive Displacement and Dynamic Blowers 163

For a dual drive unit, the driver that will operate longer is set perfectly
level on the held bearing end of the shaft and the driver that will operate
for shorter durations is placed on the free bearing end of the shaft.

Housing Completion

With the wheel and shaft in place in the bearings, erect the remaining
housing sections. Place the gasketing material shipped with the unit at the
split sections and assemble. If necessary, use a drift pin (moderately) to
align bolt holes. No gasketing is to be used at the intersection of the inlet
boxes and housing or at inlet cones. Gasket material is to be used at the
split section of the housing only. If a special housing section is to be
welded, the matching sections have bolt-through position clips that en-
sure a correct match and hold the section until seal welding is completed.
Both bolted and welded inlet boxes are used. For welded styles that
cannot be shipped attached because of freight limitations, positioning
clips on the fan housing orient the box until seal welding is completed.

CLEARANCE BETWEEN WHEEL INLET AND INLET
BELL TO ALLOW FOR GROWTH OF SHAFT. AT
OPERATINO TEMPERATURE
WHEEL INLET OVERLAPS INLET BELL
INLET BELL ADJUSTABLE
AT INLET RING
I

E . 'LI NQ WITH
IAL INC WATOR
*
1
I ARA ,LLEL
A
SHAFT DEFLECTION IS EXAGGERATED TO SHOW
INBOARD BEARING, PEDESTAL AND DRIVE
LEVEL. SHAFT DEFLECTION IS SLIGHT AND IS
THE SAME WHETHER FAN IS IDLE OR
OPERATING. BEARING LINER WILL CORRECT
MINOR MISALIGNMENT.

Figure 4-15. Expansion adjustmen! for high-temperature fan application. (Courtesy CBKP
Ltd.)