基于声波团聚的热脱附装置除尘的关键影响因素研究

Experimental studies on key parameters of the dust removal of soil thermaldesorption device using acoustic agglomeration

针对土壤热脱附装置存在着严重的扬尘问题,将声波团聚联合喷雾的方法应用于热脱附装置的除尘,研究了声频、粉尘初始浓度、声压级和喷雾流量等对除尘效果的影响(粉尘的平均粒径小于10μm)。实验发现,在声频为1400 Hz、喷雾浓度为1.0 L·m^(-3)的条件下,团聚室的除尘效率在60 s内达到98%;声压级从145 dB提高至153 dB后,除尘效率提高了38%;SEM结果表明,声波处理后的颗粒被碾碎并团聚;添加喷雾可以提高除尘效率,但不同的喷雾浓度对最终的除尘效率影响不大,施加喷雾后的最佳声频仍为1400 Hz;粉尘和喷雾的初始浓度越大,团聚前期的除尘速率和最后的除尘效率越大,当喷雾浓度为2.0 L·m^(-3)时比没有喷雾时的除尘效率提高了44%,说明声波团聚对高浓度气溶胶的使用效果更好,研究结果可为热脱附装置除尘技术的研发提供参考。

In order to solve the serious dusting problem for soil thermal desorption device,the method of acoustic agglomeration combined spray was applied to the dust removal of the thermal desorption device.The effects of sound frequency,initial dust concentration,sound pressure level and spray flow rate on the dust removal efficiency(average particle size of dust less than 10μm)were studied.The experimental results showed that under the condition of sound frequency of 1400 Hz and spray concentration of 1.0 L·m^(-3),the dust removal efficiency of the agglomeration chamber reached 98%within 60 s.When the sound pressure level was increased from 145 dB to 153 dB,the dust removal efficiency is increased by 38%.SEM results showed that the particles were crushed and aggregated after acoustic wave treatment.Adding spray could improve the dust removal efficiency,but the effect of spray concentration on final dust removal efficiency was not significant.The optimal sound frequency after spraying was 1400 Hz.The higher initial concentration of dust and spray could lead to the higher dust removal rate and the final dust removal efficiency in the early stage of agglomeration.When the spray concentration was 2.0 L·m^(-3),the dust removal efficiency was 44%higher than that without spray,indicating that the acoustic wave agglomeration had a better effect on the use of high concentration aerosol.The results of this paper could offer useful information in the investigation and development of dust removal technology of thermal desorption device.