# World Environmental Day Essay Regarding

Topics: Centrifugal pump, Pump, Fluid dynamics Pages: 31 (9457 words) Published: May 30, 2011
Centrifugal Tutorial
Centrifugal Pump
A centrifugal pump is one of the simplest pieces of equipment.  Its purpose is to convert energy of an electric motor or engine into velocity or kinetic energy and then into pressure of a fluid that is being pumped.  The energy changes occur into two main parts of the pump, the impeller and the volute. The impeller is the rotating part that converts driver energy into the kinetic energy.  The volute is the stationary part that converts the kinetic energy into pressure. Centrifugal Force

Liquid enters the pump suction and then the eye of the impeller. When the impeller rotates, it spins the liquid sitting in the cavities between the vanes outward and imparts centrifugal acceleration.  As the liquid leaves the eye of the impeller a low pressure area is created at the eye allowing more liquid to enter the pump inlet. Centrifugal Pumps are classified into three general categories: |CENTRIFUGAL PUMPS | |[pic] | |RADIAL FLOW |MIXED FLOW |AXIAL FLOW |

Radial Flow - a centrifugal pump in which the pressure is developed wholly by centrifugal force. Mixed Flow - a centrifugal pump in which the pressure is developed partly by centrifugal force and partly by the lift of the vanes of the impeller on the liquid. Axial Flow - a centrifugal pump in which the pressure is developed by the propelling or lifting action of the vanes of the impeller on the liquid.

Positive Tutorial

Positive Displacement Pumps are classified into two general categories and then subdivided into four/five categories each: |POSITIVE DISPLACEMENT PUMPS | |[pic] | |SINGLE ROTOR |MULTIPLE ROTOR | |[pic] |[pic] | |VANE |GEAR | |PISTON |LOBE | |FLEXIBLE MEMBER |CIRCUMFERENTIAL PISTON | |SINGLE SCREW |MULTIPLE SCREW | |PROGRESSING CAVITY | | |  | |

• SINGLE ROTOR
o VANE - The vane(s) may be blades, buckets, rollers or slippers which cooperate with a dam to draw fluid into and out of the pump chamber. o PISTON - Fluid is drawn in and out of the pump chamber by a piston(s) reciprocating within a cylinder(s) and operating port valves. o FLEXIBLE MEMBER - Pumping and sealing depends on the elasticity of a flexible member(s) which may be a tube, vane or a liner. o SINGLE SCREW - Fluid is carried between rotor screw threads as they mesh with internal threads on the stator. o Progressing Cavity - Fluid is carried between a rotor and flexible stator.

• MULTIPLE ROTOR
o GEAR - Fluid is carried between gear teeth and is expelled by the meshing of the gears which...