Experimental study on promotion of coal combustion fine particles acoustic agglomeration removal by using wetting agents

The characteristics of agglomeration removal between wetting agent droplets and fine particles were investigated in an acoustic agglomeration chamber. A novel technique using wetting agents to promote the fine particle capture by acoustic agglomeration was presented. The experimental results show that the type of wetting agent has a significant effect on the acoustic agglomeration of fine particles. The particle stage removal efficiencies using JFC and FS-310 are similar to that using plain water droplets, but the removal efficiencies by SDS and Silanol w22 are much higher than that using water droplets. Fine particle removal efficiency in the acoustic field correlates well with the wettability of wetting agents, which decreases with increasing the relative contact angle of wetting agents. While the relative contact angle descends from 83° to 0°, the removal efficiency of fine particles with sound pressure level of 150 dB increases by about 18%. However, the removal efficiency of fine particle without acoustic effects only increases by about 5%. Higher sound pressure level can improve the particle removal efficiency that is extremely low when the sound pressure level is below 150 dB. However it can be improved with wetting agents addition to the atomization droplets. The capture efficiency can be increased by 25% with SDS adding than acoustic effect only under the sound pressure level of 130 dB. It indicates that the removal of fine particles is effectively improved by using wetting agents with acoustic wave agglomeration, and the high removal efficiency can be achieved at a low sound pressure level.