Date post: | 09-Aug-2015 |
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Pump classification
Hydrodynamic (or) non-positive displacement pumps
Hydrostatic (or) positive displacement pumps
Hydrostatic pumps:Hydrostatic pumps uses fluid pressure to transmit power.These pumps may be either….. a) Fixed displacement b) Variable displacementIt is also called as positive displacement pumps.
HYDRODYNAMIC PUMPS:Carries fluid from one location to another, relatively at low pressure (17-21 bar).Generally used for low pressure, high-volume, flow applications. Examples….. a) Centrifugal pumps b) Axial flow propeller pump.These pumps are called as non-positive displacement pumps.
GEAR PUMPGear pumps are positive displacement rotary pumps that transport liquids using rotating gears
VANE PUMPa positive displacement pump with reciprocating rotary motion of the operating member
Anticlockwise rotation
PISTON PUMP
A piston pump is a type of positive displacement pump where the high-pressure seal reciprocates with the piston
PUMP EFFICIENCIES
Volumetric Efficiency:η = Actual flow rate = Qa Theoretical flow rate QtGear pumps = 80-90 %Vane pumps = 82-92 %Piston pumps = 90-98 % Mechanical Efficiency:η = Output power = Po Input power PiMechanical efficiency varies from 90 to 95 %Overall Efficiency:η = Actual power delivered by the pump = Hydraulic power Actual power delivered to the pump = Brake power