ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

The drainage pressure difference of self-cleaning screen filter was calculated, and the total value of pressure difference for 80 mesh and 120 mesh was also calculated respectively at first. Contrasting with measured value, the result indicated that the calculated value and measured value were substantial identical. Then, the law of pressure difference was analyzed particularly, which influenced by restriction condition as flow, sand and time, etc. Finally, the variation curve of clean and muddy head loss acquired by the experiments, under the condition that the head loss could not ascend sharply, the best drainage pressure difference for two kinds of mesh was put forward, which could provide reference for the pressure difference calculation of screen filter.