What are the types of air preheaters for circulating fluidized bed boilers?

　　There are three types of air preheaters currently used in circulating fluidized bed boilers. Most circulating fluidized bed boilers use tubular air preheaters, which are divided into vertical tube type and horizontal tube type; a few circulating fluidized bed boilers use tubular air preheaters. The fluidized bed boiler uses a heat pipe air preheater; the third type is a rotary air preheater, which has the advantage of being relatively small in size and suitable for large-capacity circulating fluidized bed boilers. Due to the high primary air pressure of the circulating fluidized bed boiler, in order to avoid excessive air leakage coefficient, the rotary air preheater used in the circulating fluidized bed boiler adopts a special binning and sealing method.