Brief Introduction of the CFB Boiler The circulating fluidized bed boiler is a high pressure, single drum, steel structure and natural circulation boiler. The arrangement for the integrated boiler is adopted. Rectangular section of the combustion is adopted for the boiler. The membrane wall construction is arranged for the four sides walls of the furnace and enclosure of the rear pass. Water-cooled platen and secondary super-heater are arranged in the furnace while abrasion resistant refractory is lined in the emulsion zone at the lower part of the furnace to protect the furnace from erosion in operation. The super-heaters are divided into SH1, SH2 and SH3. Convection super-heater, economizer and horizontal tubular air pre-heater with primary and secondary airflow separators are arranged in the rear pass in sequence. Two hot or steam-cooling cyclones with U type loop seal is arranged between the furnace and rear pass of the boiler. The cyclones are lined with refractory to assure reliable operation. Anti-explosion buck-stay and expansion center with non-metal expansion joint are arranged for the boiler to solve the tri-direction expansion problem. Technical Features of the Boiler * The design of the advanced water-cooled grid with even distributed air, large bell type nozzle, reasonable resistance and no blocking makes the boiler long service life ; * Large width-to-depth ratio of the furnace to facilitate the secondary air passing through and being mixed ; * High efficiency heat insulation cyclone separator is adopted ; * Stable and reliable operation and high efficiency insulated or air-cooled cyclone ; * Self equilibrating U type loop seal for returning the circulating material to make the control simple and reliable ; * Three stage super-heater arrangement with the secondary super-heater in the furnace to improve the radiant characteristic of the super-heater efficiency ; * Spray type de-super-heating is adopted to get fast de-super-heating reliably and safely ; * Tubular air pre-heater with the primary and secondary air separate arrangement.