气固环流反应器内颗粒返混特性

Back-mixing of Particles in a Gas-Solid Loop Reactor

采用光纤测量与数据处理方法,在不同操作条件下,对一套大型组合流化床燃烧器环流段内固体颗粒的局部返混及截面返混特性进行了测定.结果表明,以颗粒局部返混比Rmix,L表征的局部返混特性规律为在环隙区的径向分布较均匀、而在其他区域(导流筒区、底部区和颗粒分流区)呈中心区小边壁区大的不均匀分布形态.在环流反应器的整个流动区域内,Rmix,L变化范围为0～0.9,颗粒截面返混比Rmix,T变化范围为0.1～0.6.

Under different operation conditions, by optical fiber measurement with suitable data processing, the local and cross-sectional particle back-mixing characteristics in the riser and annular sections of a large-scale compound fluidized bed combustor were investigated. The experimental results show that the radial distribution profiles of particle local back-mixing ratio （Rmix,L） is uniform in the annulus, but non-uniform in other three regions （draft tube, bottom and particle separation regions） of the loop reactor. The value of Rmix,L in the loop reactor varies from 0 to 0.9. And the value of the particle cross-sectional back-mixing ratio ranges from 0.1 to 0.6 in the whole region of the reactor.