种子颗粒对声波团聚效率的影响

可吸入颗粒物PM10,尤其是细颗粒物PM2.5是影响空气质量的重要污染物,这些颗粒物粒径小、数目多、富集多种有害物质,在周围环境中可以存在很长时间,对人体健康和大气环境有很大影响.

Effect of seed particles on acoustic agglomeration efficiency

Fine particle agglomeration technique is an effective method to control the air particle pollution, and acoustic agglomeration is considered as one of the most promising techniques.In this study, large size lime seed particles were introduced to the acoustic agglomeration experiment at low frequency (1000—2000 Hz).The distribution of fine particles was measured online by electrical low pressure impactor (ELPI）to investigate the effect of lime seed particles on acoustic agglomeration.The results show that the acoustic agglomeration with lime seed particles can attain higher agglomeration efficiency, with the best efficiency of 70.5%.For the cases with low acoustic agglomeration efficiency, the introduction of lime seed particles improves the agglomeration efficiency significantly, and the highest increment in agglomeration efficiency reaches 15.5%.The agglomeration efficiency depends on the sound frequency, sound pressure level, residence time, amount and size of seed particles.The introduction of lime seed particles can expand the “frequency window” and give a better agglomeration effect even at lower sound pressure level, and decrease the dependence on the size of agglomeration equipment, which improves the performance of acoustic agglomeration and reduces the energy consumption.The results show that the amount of seed particles should be appropriate and excessive seed particles will reduce the agglomeration efficiency.The size of seed particles should be moderate, otherwise the improvement of agglomeration efficiency is limited.