Page 160 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Chapter 4

Posltlve Displacement and
Dynamic Blowers

Maintenance instructions for Positive Displacement Rotary Blowers'

Process plants frequently employ rotary positive displacement blowers
utilizing a 3-lobe rotor design. The rotors are driven by timing gears.
Ball bearings at each end of the rotors provide support and control lim-
ited clearances. Internal parts are lubricated by splash oil lubrication. Lip
seals are used to control process gas leakage. A cutaway picture of a typi-
cal blower is shown in Figure 4-1A.

Materials of Construction

Rotors with integral shafts, housing and end plates are made of ductile
iron.

Disassembly (Figure 4-1 B)

Disassembly procedures are generally simple and straightforward.
Here is a typical sequence for the blower shown. It may have to be modi-
fied for different types or models:
1. Drain oil from blower.
2. Remove drive end cover (6) and flanged drive shaft (45) from
drive gear.
3. Mark all parts with a center punch so they can be reassembled in
same position.
* Courtesy of M-D Pneumatics Inc., compiled by H. Y. Hung, Esso Chemical Canada,
Ltd., Sarnia, Ontario.
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