流化风速对二元粒径颗粒混合物分层特性影响的实验研究

Experimental Study of the Effect of Fluidization Velocity on the Segregation of Two Size Particles System

采用塌落法针对2种不同粒径颗粒的混合物,研究了其在不同流化风速下,颗粒平均粒径沿床高的分布情况。研究发现,随着流化风速的增大,颗粒平均粒径沿床高的分布逐渐趋于均匀。表明增大风速有利于颗粒之间的相互混合,减弱颗粒分层。这对防止风水联合冷渣器内结焦事故的发生具有重要意义。

The profile of average particle diameter in bubbling fluidized bed was studied in a laboratory-scale plant by studying the subsidence curve after a abrupt termination of the fluid supply. Binary mixture was composed of two typical size of particles to simulate the in- ventory in the ash cooler of circulating fluidized bed boiler. It was resulted that the profile of average particle diameter tended to be uniform when the superficial gas velocity increased. It indicated that the increasing of superficial gas velocity was propitious to particle mixing in bubbling fluidized bed. It also made sense to prevent slagging in a certain kind of ash cooler.