Question

hi please elaborate rotary positive displacement working principle with labelled and the flow image , application and limitation

Answer 1

Rotatry positive displacement pumps uses actions of rotating elements to compress/ transfer the fluid. (Unlike reciprocating pumps where backward and forward motion of the piston is used). ROtating element and the casing of the pump, together, creat a sealed compartment for the liquid. This also generateds suction in the inlet, and compression in the compartment. Fluid is drawn into the pump and enclosed in between rotating ements tooths.Then it is transferred to discharge.

Application:

For Higher flow rate then reciprocating pumps

For higher viscosity fluid

Used for Lesser noise and vibration then reciprocating counterparts

When high pressures are required

Limitations:

Design Complexity

Difficult to maintain

Flow rates not high as centrifugal pumps