Tranport Phenomena

Mechanical devices are usually used to supply energy or driving force in order to make a fluid flow from one point to another .There are different kinds of mechanical devices used to transport fluids, namely, pumps, fans, blowers and compressors. Though liquids particularly can be transported by operators carrying buckets, the usual mode of transport of fluids is through pipelines with pumps, compressors, fans and blowers. Generally, the word “pump” designates a machine or device for moving an incompressible liquid while fans, blowers and compressors are devices for moving gas (usually air).
PUMPS
There are three common types of pumps: the centrifugal pump, the reciprocating pump and the rotary pump. Centrifugal pump uses centrifugal action as the method of adding energy or driving force while in reciprocating pump and rotary pump positive displacement of adding energy or driving force is the method used.
Centrifugal pump in its simplest form consists of an impeller rotating inside a casing. It is commonly used in process industries because centrifugal pumps deliver liquid at uniform pressure without shocks or pulsations and can handle liquids with large amounts of suspended solids. Centrifugal pumps are limited in their head and are used for low pressures.
Reciprocating and rotary pump are pumps that belong to positive-displacement type. Positive-displacement pumps work on principle where a definite volume of liquid is drawn into a chamber and then forced out of the chamber at a higher pressure. In reciprocating pump the chamber is a stationary cylinder, and liquid is drawn into the cylinder by withdrawal of a piston in the cylinder where the liquid is forced out by the piston on the return stroke. In rotary pump, the chamber moves from inlet to discharge and back again. Reciprocating pumps and rotary pumps are basically used in very high pressures.
Power and Work Required in Pumps
Using the total energy balance on a pump and piping system, the actual or