CAF涡凹气浮装置在炼油污水处理中的应用

The Application of CAF Vortex Concave Floating Unit in Refinery Sewage Treatment

某企业污水处理场新建一套CAF涡凹气浮装置,主要由曝气区、气浮区、回流系统、刮渣系统及排水系统组成。其工作原理为:加混凝剂后的污水进入装有涡凹曝气机的曝气区,该区设有独特曝气机,通过底部中空叶轮的快速旋转,在水中形成一个真空区,水面上的空气通过中空管道抽送至水下,并在底部叶轮快速旋转产生的三股剪切力下把空气粉碎成微气泡,微气泡与污水中的固体污染物结合在一起升到液面,通过刮渣机,将浮渣刮入污泥收集槽并排出系统,净化后的水由溢流槽溢流进入后续处理设施。药剂组合选用PAM+PAC混合使用。CAF涡凹气浮装置调试运行期间,水处理量在400～500t/h,曾出现处理效果不能满足设计指标(浮选池进口油含量小于200mg/L)要求,加药管线堵塞,浮渣池存储容量不足等问题。后经采取加大管线口径(由DN40改为DN50)、更换药剂(选择有机高分子药剂替代PAM+PAC药剂)、增设浮渣池脱水管线等措施,取得成效,出水平均油含量基本稳定在61mg/L。

An enterprise added a CAF vortex concave floating unit for its sewage treatment plant.The new system consists of an aeration zone,a floating zone,a reflux system,a scum-scrapping system and a drainage system.Its working principle is： sewage with coagulant enters the aeration zone equipped with vortex concave aerators;the aeration zone is equipped with unique aerators,which can produce a vacuum area in the water by rapidly rotating their hollow impellers at the bottom of the aerators;The air at the surface of water is pumped to below the surface of water through a hollow tube;three shear forces produced by the rapid rotation of the bottom impellers shatter air into microscopic bubbles,which will rise to the surface of the liquid after combining with the solid pollutants in the sewage;a scum-scrapping machine is used to scrap the floating scum into a sludge collecting tank and the scum is then discharged out of the system;the purified water overflows out of an overflow launder into follow-up treatment facilities.The agent used is a mixture of PAM and PAC.During commissioning of the CAF vortex concave floating unit,the sewage treatment volume stood at 400-500t/h.Some problems appeared during that period.The effect of sewage treatment was below the designed specifications（the content of oil at the inlet of the flotation tank was less than 200mg/L）;the pipeline for adding agents was clogged;the storage capacity of the scum tank fell short of demand.After the caliber of the agent-adding pipeline was expanded（from DN40 to DN50）,the agents used were replaced（using organic polymer agents to replace PAM plus PAC） and a dewatering pipeline was added for the scum tank,the average content of oil in the effluent has basically stabilized at 61mg/L.