Abstract: The microbubble absorption method is effective to remove organic compounds from waste gas. Generally, the microbubbles are generated by dispersing the waste stream into an absorber liquid. The microbubble absorption has the advantages of large contact area and high mass transfer rate. Water was used as the liquid media to absorb acetone from the waste gas of acetone-air mixture. Microbubbles were generated by a microporous plate with pore sizes of 3 to 4 microns and the bubble diameters were measured by the high-speed imaging method. The effects of operation parameters on the absorption efficiency were investigated experimentally. The results showed that the average diameter of the microbubbles decreased while the bubble numbers increased with the increasing of the superficial gas velocity and the concentration of acetone in water. By keeping the acetone concentration in water in the range of 1% to 3% and the superficial gas velocity of 10.2m/s, microbubbles with diameters of 300祄 to 700祄 were generated successfully through the microporous plate. The absorption efficiency changed with the variations of superficial gas velocity and the acetone mass concentration in the air-acetone waste gas. At the superficial gas velocity of 10.2m/s, the absorption efficiency increased with the increase of the acetone mass concentration in the waste gas and the maximal absorption efficiency was 77.16% at the acetone mass concentration in the waste gas of 1.56×10^-3kg/m³.

Key words: microbubble, absorption, size distribution, organic waste gas, porous media

摘要： 微泡吸收技术是将有机废气在吸收剂中分散为尺寸微米量级的微气泡, 利用微气泡气液接触面积大、传质迅速等优点实现有机废气吸收处理的方法。本文以水为吸收剂, 采用孔径3～4μm 的多孔微孔板形成废气微气泡, 利用微泡吸收技术从空气-丙酮废气中吸收丙酮。利用高速摄影方法对不同条件下微气泡的直径分布进行了实验研究, 并对丙酮的吸收效果进行了实验测定。结果表明, 随着表观气速的增加微气泡的平均直径降低而数量增加;随着水中丙酮浓度的提高, 微气泡平均直径逐渐降低, 数量增加。当丙酮体积分数在1%～3%范围、表观气速为10.2m/s时, 采用孔径3～4μm的多孔微孔板能产生直径为300～700μm微气泡。表观气速和废气中丙酮的质量浓度的变化影响丙酮的吸收率;一定表观气速下, 吸收率随废气中丙酮质量浓度的增大而增大, 空气-丙酮混合气体中丙酮质量浓度为1.56×10^-3kg/m³和表观气速为10.2m/s时, 吸收率达77.16%。

关键词: 微气泡, 吸收, 直径分布, 有机废气, 多孔介质