Air distributing device of circulating fluidized bed boiler

The utility model discloses an air distributing device of a circulating fluidized bed boiler, which comprises an air distributing plate, a plurality of air pipes which penetrate the air distributing plate to extend and air caps installed on each of the air pipes. The air caps are provided with holes communicated with the air pipes, and the diameters of the holes of the air caps in the central area of the air distributing plate are smaller than those of the holes of the air caps in other areas. Through reducing the diameters of the holes of the air caps in the central area in which the thickness of bed materials is smaller, air quantity of the area is reduced and accordingly air quantity of the surrounding is increased. Simultaneously, resistance of air distribution is increased, thereby increasing the speed of air passing through the central area and the surrounding areas to be sent to a boiler furnace to facilitate fluidizing of bed materials. Therefore, air at different scales can be provided according to d