Page 66 - Know and Understand Centrifugal Pumps

Useful Work and Pump Efficiency

have 2 or 3 blades on a specially designed impeller with lower
efficiency.
7. The type of pump - There arc many types of pumps with
configurations and characteristics for special services, such as
sanitary, wastewater, and solids handling, etc., taking into account
the Ns and design that perform their services effectively with a
slightly less than optimum efficiency. In simple terms, special
designs and services generally reduce efficiencies.

Efficiency = Work Output = Power Produced
Work Input

Water Horsepower - =I>
Pump Efficiency = -
Brake Horsepower BHp

H x Q x sp. gr.
Pump Efficiency =
3960 x BHp

Pump Horsepower - BHp
-
Coupling Efficiency =
Motor Horsepower Hp
Motor Horsepower Output - Hp
Motor Efficiency = -
Energy / Power Input Kw

H x Q x sp. gr.
BHp =
3960 x eff.

ELECTRIC
ENERGY IN

Figure 5-4
~ ~.
49 FI