燃气过滤器滤网流阻特性及压差评价

Flow Resistance Characteristics and Pressure Difference Evaluation of Gas Filter Screen

通过试验的方法确定了不同过滤精度(10、20、50、100μm)洁净滤网的流阻特性,并对不同试验压力下洁净滤网和含尘滤网进行了流阻特性验证;基于滤网的流阻特性提出在役燃气过滤器压差评价方法,给出过滤器压差评价流程,进而有效评估过滤器压差的状态,避免出现过滤器滤芯失效。研究结果表明:滤网的过滤精度越小,滤网前后压差越大,尤其是常用的10μm滤网,其滤网前后压差是50μm和100μm滤网的10倍以上。对洁净滤网,滤网前后压差随滤网流速的变化规律符合多孔介质模型的形式,为惯性项与黏性项之和,随着过滤精度的增大,惯性项在压差中所占比例增大,黏性项所占比例减小。对含尘滤网,滤网的流阻特性符合多孔介质模型的形式,随着含尘程度的增大,滤网前后压差变大。

The flow resistance characteristics of clean filter screens with different filtration accuracy(10,20,50 and 100μm)are determined by test method,and the flow resistance characteristics of clean filter screens and dust-containing filter screens under different test pressures are verified.Based on the flow resistance characteristics of the filter screen,the pressure difference evaluation method of the in-service gas filter is proposed,and the pressure difference evaluation process of the filter is given,so as to effectively evaluate the state of the pressure difference of the filter and avoid the failure of the filter element.The results show that the smaller the filtration accuracy of the filter screen,the greater the pressure difference between the front and rear of the filter screen,especially the commonly used 10μm filter screen,the pressure difference before and after the filter screen is more than 10 times of that of 50μm and 100μm filter screen.For the clean filter screen,the variation law of the pressure difference between the front and rear of the filter screen with the flow rate of the filter screen conforms to the form of porous media model,which is the sum of inertia term and viscosity term.With the increase of filtration accuracy,the proportion of inertia term in the pressure difference increases and the proportion of viscosity term decreases.For the dust-containing filter screen,the flow resistance characteristics of the filter screen conform to the form of porous media model.With the increase of dust content,the pressure difference between the front and rear of the filter screen becomes larger.