在可吸入颗粒团聚室中引入气体射流,使团聚室内形成局部湍流强化颗粒碰撞.团聚过程中以撞击式采样器和激光粒子计数器测量可吸入颗粒团聚前后质量与数量变化来评价颗粒的团聚效率.研究结果表明,增大射流出口雷诺数和增大射流与主气流的气速比均能提高可吸入颗粒的清除效率.射流对不同粒径颗粒的清除效率不同,粒径较小颗粒(〈1.0μm)的清除效率最高.团聚室内气体相对湿度在40%~50%时,颗粒清除效率最高,团聚后颗粒质量中位径由2.83μm增大到5.03μm.增大飞灰质量浓度,可吸入颗粒的质量清除效率与数量清除效率均降低.
A turbulent gas jet was introduced in an agglomeration chamber to generate a local turbulent flow field and intensify agglomeration process of inhalable particles. Aerosol cascade impactor and laser particle counter were used to measure the mass and number variations of particles after agglomeration. The parameters influencing particle agglomeration were examined in detail. The experimental results showed that the removal efficiency increased with increasing Reynolds number of jet exit and flow ration of jet-crossflow. However, the removal efficiency was affected by particle diameters, and the maximum efficiency observed in small particles (〈1.0 μm). When relative humidity in the chamber approached 40%-50%, the maximum removal efficiency was acquired, in which the mass diameter increased from 2.83 μm to 5.03 μm. Increment of initial concentration of fly ash could resulted in decreasing of removal efficiency of inhalable particles.