折流式厌氧反应器水力特性分析

折流式厌氧反应器(ABR)的处理效果受水力特性的影响较大,而水力停留时间(HRT)又是影响反应器内水力特性的一个重要因素。运用欧拉双流体模型和标准k-ε紊流模型,对不同HRT下ABR反应器内的多相流流场进行三维数值模拟,并从反应器内水流速度、固含率两个方面探讨分析了HRT对反应器内部流场特性的影响。分析结果表明:HRT变化对各反应室内降流区水流速度的影响不大,升流区内的循环水流速度随HRT的减小而增大;反应器内污泥颗粒的分布范围受HRT影响显著,HRT过短或过长,均不利于提高反应器的处理效率,5~8 h时为ABR反应器的最佳水力停留时间,最有利于去除污废水中的污染物。

Analysis of hydraulic characteristics of anaerobic baffled reactor

The hydraulic characteristic of the anaerobic baffled reactor (ABR) is an important factor affecting its treatment effects. Hydraulic retention time (HRT) has a greater influence on the hydraulic characteristic of the reactor. A double flow model and a k-ε turbulence model have been used to simulate the three-dimensional flow field in the anaerobic baffled reactor at different HRT and analyze the influences given by HRT on the hydraulic characteristic of inner flow field of the reactor from both water flow velocity and solid holdup. The analysis results show that HRT has a little influence on the flow velocity of the down-flowing compartment, however, there is an increase in the velocity of circulating water flow with decrease in HRT in the up-flowing compartment. HRT has a great influence on the distribution of the solid holdup. Either the shorter HRT or the longer HRT has a negative effect on the improvement of the efficiency of the reactor. The optimal hydraulic retention time of the reactor is 5~8 h, which is the most favorable for the removal of pollutants in the waste water.