逆流型废液与非饱和空气的热质交换性能研究

Heat and Mass Transfer Performance Between Waste Liquid and Unsaturated Air

提出了一种新型的逆流形式的填料塔废液处理装置,对含水率为94%的金属切削废液与非饱和空气进行热质交换实验研究,获得了不同运行工况下废液和空气的进出口状态参数,然后基于传质单元数-路易斯数模型,使用路易斯数-换质系数分离测量法对实验数据进行处理,获得了传质系数αm和路易斯数Le,进而计算出传热系数α,分析运行参数对传热传质系数和Le的影响。研究发现,空气流量、废液流量和废液温度的增大都会使得传热传质系数增加;空气流量和废液流量对Le的影响很小,变化范围在0.96~0.99,随着废液温度的增大,Le明显减小,从1.3降低到0.71。

A new kind of waste liquid treatment device in the form of a counter flow in packed tower was proposed,and experimental researches on the heat and mass transfer performance between metal cutting waste liquid with 94%moisture content and unsaturated air were carried out.The inlet and outlet state parameters of the waste liquid and air were obtained under different operating conditions.Based on the NTUm-Le model,the experimental data were processed by using the Le-αm separation method to obtain the mass transfer coefficientαm and Le number,and the heat transfer coefficient was then calculated.Finally,the influences of operation parameters on the heat and mass transfer coefficients and Le number were analyzed.The study finds that the increase of air flow rate,waste liquid flow rate and waste liquid temperature will increase the heat and mass transfer coefficients.The air flow rate and the waste liquid flow rate have little influence on the Le number which varies merely within the range of 0.96 to 0.99.The Le number decreases obviously from 1.3 to 0.71 with the increase of the solution temperature.