Heat exchanger is a device used for efficient heat transfer from one medium to another (from one fluid to another). The fluids are separated from each other with the help of a solid wall. The wall prevents them from getting mixed up. These devices work in coordination with storage tanks and pressure vessels. These devices are primarily used for liquid separation. These devices are widely used in chemical plants, petrochemical plants, petroleum refineries, natural gas processing, power plants, sewage treatment, air conditioning, space heating and refrigeration systems. This device is also found in internal combustion engines. Few common exchangers available in the market today are plate, plate fin, new brazed, new specialist , shell and tube, adiabatic wheel, pillow plate, fluid and phase-change heat exchangers. http://amplify.com/u/a1j4il