Abstract: The formation of fly ash deposition on heat transfer tubes in a boiler taken as the research background,an experiment of fly ash particle impacting plate at ambient temperature and pressure was carried out to investigate the effects of initial velocity and fly ash particle diameter on normal coefficient of restitution.The experimental results show that when particle diameter remained constant,normal coefficient of restitution e_n first increased,then leveled,and finally decreased as normal incident velocity v_i,n increased,and in the rapid increase region of e_n,the slope of the experimental curve(e_n vs v_i,n)was very large.This was due to the variation of the ratios of different types of energy to the total energy in the different ranges of normal impact velocity.When normal incident velocity remained constant,normal coefficient of restitution increased as particle diameter increased.The critical capture velocity changed with microsphere diameter,the larger the size,the smaller the capture velocity.

Key words: particle deposition, incident normal velocity, normal coefficient of restitution, critical velocity

摘要： 以煤粉锅炉积灰过程为研究背景,在常温常压环境下对飞灰颗粒与平板表面撞击过程进行实验研究,分析飞灰颗粒入射法向速度对颗粒法向反弹速度的影响,以及飞灰颗粒粒径对临界捕集速度的影响。实验结果表明,飞灰颗粒粒径相同时,法向恢复系数随入射法向速度的增大先增大后平缓最后减小,在增大区域具有相当陡的斜率,反映了不同形式的力在不同阶段所占的比重不同;颗粒入射法向速度相同时,法向恢复系数随着颗粒粒径的增大而增大;而临界捕集速度随颗粒粒径的增大而减小。

关键词: 颗粒沉积, 入射法向速度, 法向恢复系数, 临界速度