新型气液逆流撞击洗涤喷嘴的优化

Optimization of new type of gas-liquid countercurrent impinging scrubber nozzle

针对一种新型气液逆流撞击式洗涤喷嘴,通过冷模实验,采用溶氧法考察了不同结构喷嘴的气液两相传质性能。结合解析率及流型变化,考察了喷嘴出口直径、切向进液口倾角、旋流室收敛段锥角、切向进液口直径、喷口长度5个参数对传质的影响,确定了优选喷嘴的结构尺寸,分析了该优选喷嘴在不同操作条件下(气速、表观液气比和轴切比)的传质效果。结果表明,优选喷嘴在轴切比为0.4～0.6且气速较高时传质效果较好。

A new type of gas-liquid countercurrent impinging scrubber nozzle was put forward.By using the dissolved oxygen technique,the characteristics of the gas-liquid two-phase mass transfer with different structures of scrubber nozzles were investigated through cold model experiment.Combining the measured desorption rates with the observed flow patterns variation,the effects of five structural parameters including the nozzle outlet diameter,the tangential inlet angle,the conical swirl chamber cone angle,the tangential inlet diameter and the spout length on the mass transfer were analyzed.Thus the optimalstructural dimensions were given.The features of the mass transfer of the optimal nozzle under different operating conditions including the gas velocity,the superficial liquid-gas volume flow rate ratio,and the axial-tangential volume flow rate ratio were investigated further.The nozzle with structure of horizontal angle of the tangential inlet,small outlet diameter(with high orifice speed),and small conical angle of the convergent section of the swirl chamber can gain high mass transfer efficiency.For industrial applications,large size scrubbers should provide as much tangential momentum as possible to cover the entire cross section and increase the gas-liquid contact area,such as choose the angle 0?and 90?,tangential inlet angle and conical swirl chamber cone angle respectively.The results showed that the desirable effect of mass transfer could be obtained then the axial-tangential volume flow rate ratio was 0.4~0.6,especially in a high gas velocity condition.Similarly,there was a better mass transfer area with the change of superficial liquid-gas volume flow rate ratio.In addition,high desorption rates can be achieved with a very small liquid-gas volume flow rate ratio under the condition of high gas velocity.It can also be concluded that this type of washing nozzle with higher operating elasticity can adapt to different conditions of liquid-gas volume flow ratio by adjusting the axial-tangential volume flow rate ratio.