Experimental research on the Fragmentation of Long-Yan anthracite with different lithotypes in Fluidized Bed Combustion

Abstract

Experiments were conducted in a pilot scale fluidized bed furnace. 3 different lithotypes of Long-Yan anthracite particle with different size were measured. It is shown from experiments that: (1) Clarain and culm coal occurs tremendously fragmentation and the fragmentation tends severely with the increase of particle size, bed temperature, and combustion time. Durain coal occurs no obviously fragment during combustion; (2) Both clarain and culm coal undergo secondary fragmentation during combustion, but the secondary fragment of clarain coal is more severely: in the later stage of combustion, the particle size of clarain coal fell down more rapidly than culm coal; (3) In the earlier stage of combustion, the mean size of clarain particle decreases promptly as a result of primary fragmentation, but with the time going, it falls to a steady level. (4) The clarain of Longyan anthracite combustion in fluidized bed obey a shrinking core model which the density stays constant, while the durain coal burns with diameter staying constant, and the culm coal combustion obey a double shrink core model.