脉冲式超声对污油中水滴聚并效果的影响

Effects of pulsed ultrasound on coalescence of water droplets in a waste oil emulsion

本文以炼油厂污油为研究对象,探索脉冲式超声对污油中水滴的聚并效果。比较污油中水滴直径的分布情况,发现超声对污油中水滴聚并作用效果明显,且脉冲式超声作用效果好于传统连续式超声作用效果。另外,重点考察超声类型、辐射时间、周期、脉宽、频率和声强对污油中水滴平均粒径的影响,并得到了脉冲超声破乳的最佳操作条件:脉冲式超声辐射,频率20 kHz、辐射时间6 min、周期80 ms、脉宽12 ms、超声声强04 W/m2。在最佳实验条件下,污油中水滴平均粒径由22μm增至76μm,污油中水的质量分数由60%降至7%,达到了炼油厂对污油脱水后水含量的要求(含水质量分数<10%)。

The effects of pulsed ultrasound on coalescence of water droplets in refinery waste oil emulsion were investigated.The comparison of evolutions of water droplet sizes distribution showed that ultrasound affected coalescence of water droplets in the emulsion, and the effect of the pulsed ultrasound on the coalescence was more significant than that of continuous ultrasound.The effects of ultrasonic parameters, such as the type of ultrasonic irradration, irradiation time, cycle time, pulse width, frequency, and acoustic intensity on coalescence of water droplets were discussed.Results showed that the optimum conditions for the separation of waste oil with ultrasound were as follows ：frequency of 20 kHz,irradiation time of 6 min, cycle time of 80 ms, pulse width of 12 ms, and acoustic intensity of 0. 4 W/m^2.Under the optimum conditions, the average radius of water droplets increased from 22 μm to 76 μm and water content in crude oil emulsion decreased from 60% to 7%.Thus,it satisfied the requirements of dehydration for refinery.