In the circulatory system, the bed parameter is maintained to form solid fly above bed. Solids removed in a relatively dilute phase in the riser, and a down-comer with a cyclone for the solids. There is no steam generator pipes located in the bed. Steam generation and superheating takes place in the convection, water walls, at the output of the riser.
Circulating Fluidized Bed Combustion Boilers (CFBC) is generally more economical than Atmospheric Fluidized Bed Combustion (AFBC) boiler. For application in the industry requires more than 75-100 Ton / hour steam.
For large units, the higher the characteristics of Circulating Fluidized Bed Combustion Boilers (CFBC) furnace will provide a better use of space, a larger fuel particles, the residence time absorbing materials for efficient combustion and the capture of SOx is the greater, and the easier the application of techniques for controlling NOx combustion than Atmospheric Fluidized Bed Combustion (AFBC) steam generator.
|Figure 1: Circulating Fluidized Bed Combustion Boiler (CFBC)|
(Source: Steam its Generation & Use Babcock & Wilcocx 41th)