新型流化床气溶胶发生装置及其特性

Development and characteristic of novel fluidized bed aerosol generator

根据气固流态化原理,设计了一种实用新颖的流化床气溶胶发生装置.该气溶胶发生装置可以稳定地输出高粒子数浓度、空气动力学直径小于10 μm的气溶胶颗粒物.应用该装置对燃煤电站锅炉电除尘器粉煤灰进行了气溶胶化实验.实验表明,通过改变流化气体(氮气)流量、待气溶胶化的粉煤灰和青铜珠床料组成的混合物料的给料速率以及流化床床层物料中飞灰的掺混质量比,可以调节流化床气溶胶发生装置输出的飞灰粒子数浓度.测试结果表明:飞灰粒子数浓度呈双峰分布,2个峰值分别位于空气动力学直径为0.01～0.1 μm和0.1～10 μm的范围内;飞灰质量浓度随着颗粒粒径的增大而增加.

An innovative fluidized bed aerosol generator was developed for the purpose of generating a constant output of dry, under 10μm particles with a large number concentration. The output of the fluidized bed for generating aerosol particles of dry fly ash from coal-fired utility boiler was characterized using the electrical low pressure impactor （ELPI）. The number concentration of particles produced in the range of 0.01 to 10μm was found to vary with the mass ratio of fly ash to bronze beads in the mixed bed material, and nitrogen flow rate through the fluidized bed and feed rate of the mixture. The particle size distribution is bimodal, with one mode in 0.01 to 0. 1μm diameter size range and the other in 0. 1 to 10μm diameter size range. The particle mass concentration rises with the increase of particle diameter.