This book emphasizes the Circulating fluidized bed technology which is one of the most efficient methods of coal burning in boilers for production of electric power. It has many advantages like efficient burning of coal, low emission etc. In recent years, Circulating Fluidized Bed (CFB) boilers are fast gaining importance in power generation due to dwindling reserves of high quality coal and need for abatement of atmospheric pollution due to emission of pollutant gases mainly SOx and NOx. To develop an optimum economic design of boiler, it is necessary to know how heat transfer coefficient depends on different designs and operating parameters.