Improving acoustic agglomeration efficiency by addition of sprayed liquid droplets
Improving acoustic agglomeration efficiency by addition of sprayed liquid droplets
复制标题
通过添加喷雾液滴提高声学团聚效率
DOI：
10.1016/j.powtec.2017.04.058
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发表时间：
2017-07
影响因子：
5.2
通讯作者：
Eric Hu
中科院分区：
文献类型：
--
作者：
Guangxue Zhang;Lili Zhang;Jie Wang;Eric Hu
声团聚法是一种有潜力的工业烟气前处理技术，可有效减少颗粒物排放。然而，该过程需要大量的能量投入，这限制了其商业化应用。为了减少能源需求，本研究提出向气溶胶中喷洒液滴。认为喷雾液滴通过两种机制改善声学团聚过程：1)在颗粒之间形成液体桥力，从而增加粘着系数；2)作为种子颗粒，增强颗粒之间的相对运动，从而增加碰撞几率。实验结果表明，在喷雾水滴的辅助下，声学团聚效率可提高55%。研究还发现，无论有无雾滴存在，声频对团聚效率的影响基本不变，且存在一个对应于最高团聚效率的最佳频率。唯一不同的是，当频率偏离最佳值时，有喷水时凝聚效率的下降幅度小于没有喷水时的下降幅度。随着液气比的增大，凝聚效率显著提高，当液气比大于0.13时，凝聚效率高达80%。对于纯声团聚，达到50%的团聚效率所需的声压级为146%分贝，而喷水仅140分贝时，效率可以达到55%-73%，节省了大约四分之三的能源消耗。测试了两种润湿剂(SDS和TX100)在声学团聚中的性能，与纯水相比，可使团聚效率进一步提高5%~20%。结果表明，当表面张力和接触角最小时，十二烷基硫酸钠和TX100的最佳浓度分别为0.2%和0.05%。
Acoustic agglomeration is a potential pretreatment technology for industrial flue gas to efficiently reduce particulate matter emission. However, the process requires a huge amount of energy input, which restricts its commercial industry application. In order to reduce the energy requirement, the spraying of liquid droplets into the aerosol is proposed in this study. It is thought that the droplets sprayed would improve the acoustic agglomeration process through two mechanisms: 1) increasing the adhesion factor due to the formation of liquid bridge forces between particles; and 2) as seed particles, which enhance the relative movement between particles and then increase the collision probability. The experimental results in this study show that the acoustic agglomeration efficiency can be greatly improved by up to 55% with the assistance of water spray droplets. It is also found that the influence of acoustic frequency on agglomeration efficiency basically remains unchanged regardless of the existence of spray droplets, and an optimum frequency corresponding to the highest agglomeration efficiencies exists. The only difference is that when frequency deviates from the optimum value, the agglomeration efficiency drops less sharply with the presence of the water spray than that without it. The agglomeration efficiency increases significantly with the increase of the liquid-gas ratio, up to 80% at liquid-gas ratios above 0.13. For pure acoustic agglomeration, the sound pressure level required for a 50% agglomeration efficiency is 146 dB, while the efficiency could achieve 55%–73% with water sprayed at only 140 dB, saving approximately three-quarters of energy consumption. The performance of two wetting agencies (SDS and TX100) in acoustic agglomeration is also tested, which could make a further increase of agglomeration efficiency by 5%–20% comparing to that using pure water. The results show that the optimum concentrations of SDS and TX100 solutions are 0.2% and 0.05%, respectively, corresponding to the minimum surface tension and contact angle.
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DOI：
--
发表时间：
2011
期刊：
CIESC Journal
影响因子：
--
作者：
Cen Ke-fa
通讯作者：
Cen Ke-fa
DOI：
--
发表时间：
1981
期刊：
--
影响因子：
--
作者：
F. A. Everest;Ken Pohlmann
通讯作者：
F. A. Everest;Ken Pohlmann
影响因子：
--
作者：
Kong, Shaofei;Lu, Bing;Jiang, Hua
通讯作者：
Jiang, Hua
影响因子：
4.5
作者：
T. Hoffmann
通讯作者：
T. Hoffmann
影响因子：
4.2
作者：
de Sarabia, ERF;Elvira-Segura, L;Dorronsoro-Areal, JL
通讯作者：
Dorronsoro-Areal, JL