Page 150 - Centrifugal Pumps Design and Application

128 Centrifugal Pumps: Design and Application

Figure 9-12. Propeller pump partly formed in concrete,

primary design criteria, the design is generally the same as for cooling
tower pumps. On the other hand, non-clog pumps are designed for maxi-
mum reliability and availability. The impeller is typically of semi-open
construction with two or three vanes and contoured to prevent adherence
of stringy material. Where suspended solids are a problem, provision for
clean water injection to the bearings can be provided. Handhole covers
are provided at locations where buildup of solids will require removal.

Barrel-Mounted or Can-Mounted Pumps

The most common applications for barrel-mounted pumps are:
Condensate and heater drain pumps for power plant service.
Process pumps for products with limited NPSH available.
Small boiler feed pumps for industrial applications.
Cryogenic process and transfer pumps.
Loading pumps on tank farms.
Booster pumps for pipelines handling either water or petroleum prod-
ucts.