Abstract: Water-sparged aerocyclone (WSA) is a new gas-liquid mass transfer equipment, which takes the advantage of coupling effect of air cyclone and liquid jet fields. In order to improve its mass transfer performance and establish design principles, the effect of diameter (D_e) and length (S) of the vortex finder in the WSA on its mass transfer performance and air pressure drop in air stripping of ammonia was investigated and optimized. A new concept, mass transfer efficiency per gas pressure drop, η_p, and its calculation equation were put forward. The WSA with smaller D_e and longer S showed higher mass transfer efficiency than that with larger D_e and shorter S in air stripping of ammonia. However, this kind of WSA had higher air pressure drop, which would consume more energy. Calculation of η_p, which was a comprehensive indicator considering energy consumption and mass transfer efficiency, showed that it increased with the increase of D_e/D and S/H,but it deceased a little when S/H increased from 0.71 to 0.93. The optimal D_e/D and S/H should be 0.43 to 0.53 and 0.70, respectively. These results could be used as a guide for the design of WSA with good mass transfer performance.

Key words: ammonia removal, aerocyclone, wastewater, mass transfer, gas-liquid flow

摘要： 对水力喷射空气旋流器(WSA)的中心排气管直径D_e和排气管插入深度S进行了设计优化研究,实验考察了不同D_e和S对WSA脱氨传质系数K_La和气相压降的影响,提出了综合评价传质过程效率的概念——单位压降传质效率η_p,讨论了D_e和S的设计取值。研究表明,当D_e增大时,K_La和气相压降均随之降低,较小D_e的WSA具有较高的气液传质性能,但气相压降比较大,而K_La和气相压降均随S增大而增大。综合能效关系表明,随着D_e的增大η_p增大,随着S的增大η_p出现先增大后降低的趋势,WSA设计中D_e与WSA直径D之比D_e/D宜为0.42～0.53,S与WSA筒体长度H之比S/H适宜取值约为0.70。

关键词: 脱氨, 空气旋流器, 废水, 传质, 气液两相流