曝气生物滤池流态特性研究  

Study on flowing pattern of biological aerated filter

作　　者：凌霄[1] 胡勇有[1] 马骥[1] 

机构地区：[1]华南理工大学环境科学与工程学院,广州510641

出　　处：《安全与环境学报》2005年第4期4-7,共4页Journal of Safety and Environment

基　　金：广州市科技局科技攻关重大项目(2002Z1E0022);广州市环保局市级污染防治专项资金项目(2000001)

摘　　要：为了解流体在反应器中的流动特征并为进一步提高反应器处理效率而改善水力条件,通过以KCl为示踪剂的脉冲示踪电导法对上向流曝气生物滤池在不同填料层高度和操作条件下的水力学特性进行摸拟研究。结果表明,平均停留时间主要受填料高度和水流速度影响,受气速影响较小。曝气生物滤池的流态随填料层高度的增加趋于相对稳定且接近推流;但滤床底部和顶部的流态却受水流速度和气流速度的影响较大且偏离推流。最后,建立了在曝气和不曝气两种操作条件下平均停留时间、流态与填料层高度、水流速度、气流速度的数学模型,这可用来预测反应器的流态变化特征,以改善曝气生物滤池的水力条件。The present paper intends to introduce the author＇s study on the hydrodynamic behavior of the pilot-scale upflow biological aerated filter （UBAF） filled with a media of max 2.0 m high with potassium chloride （KCI） as a tracer. First of all, in order to understand the flow nature of the fluid and improve the hydraulic condition in the reactor, we have generated a pulse input in the reactor inlet with an injector for a short time, with a 5 mL potassium chloride （ 1 mol KCI per liter）. Then the electrical conductivity at every sample reactor has successively been measured and recorded at an interval of 10 seconds on a personal computer. Once the electrical conductivity recovers its background value, the experiment would be over. The RTD experiments can be performed at the liquid superficial velocities of 9.7 m·h^-1 and 14.6 m·h^-1, 19.5 m·h^-1 under the aerated and non-aerated conditions at different filter heights （0.5 m, 1.1 m, 1.7m and 2.0 m） while me gas superficial velocities are 13 m·n^-1 , 26 m·h^-1, 39 m·h^-1 and 52 m·h^-1 respectively as aeration. As a resuit, the filter height and the operational liquid superficial velocities will have an effect on the hydrodynamic resident time （HRT）, however, the gas superficial velocities just have little influence. Of course, the influence of liquid velocity on the flow pattern proves much more important than that of the gas velocity. With the media height increased, the flow pattern of the reactor will get closer to the plug-low. The sampling results at the bottom and top of the filter bed have shown that the hydrodynamic behavior would get close to a mixed-flow. And finally, according to RTD, the mathematical models of the mean HRT and flow pattern would be built, which can be used to simulate the mean HRT and flow pattern of the reactor at different heights, liquid and gas velocity conditions. The present RTD study suggests that the present research would permit further improvement of the BAF＇s hydraulic condition.

关 键 词：环境工程 曝气生物滤池 停留时间 流态 模型 

分 类 号：X703.1[环境科学与工程—环境工程]