新型AmOn反应器好氧区流场优化与实验研究

Optimization of flow field in oxidation zone and experimental study for new AmOn bioreactor

基于气升式环流反应器原理设计的新型AmOn反应器,是集传统氧化沟和二沉池工艺于一体,同时实现有机物去除、反硝化脱氮除磷、污泥回流以及泥水分离等功能的高效污水处理生化反应器。曝气装置是该反应器的核心部件,不但起到曝气充氧、紊动传质的作用,而且还是整个反应器内液相垂直流动的动力来源。本文借助CFD技术,对好氧区曝气方式改进前后流场特征进行模拟,分析不同流场情况对好氧区紊动传质及处理效果的影响。实验表明,双管曝气方式下,中间一道曝气管的曝气搅拌作用破坏了单管曝气方式下的循环涡流,使得液速和气含率分布更加均匀合理,好氧区流场更加有利于气液和液固传质,相同曝气量条件下污水处理效果得到很大加强。

The new AmOn bioreactor,based on principle of airlift loop reactor,was designed and could integrated into a body both traditional oxidation ditch and secondary sedimentation basin,which is a high efficiency bioreactor for treatment of sewage and could realize organic matter removal,denitrification nutrients removal,sludge return and mud-water separation at the same time.Aeration device was the core part of this reactor,which could not only supply oxygen demand and turbulence in mass transfer,but also provide impetus for liquid vertical flow in the whole reactor.By means of CFD technology,the treating effect and turbulence mass transfer were analyzed for various flow field by comparing of the flow field information obtained by simulation in oxidation zoon before and after change.The experiments showed that the middle aerator pipe at two pipes condition destroyed the cycle eddy at single pipe condition,which made liquid velocity and gas hold-up more uniform and reasonable.The oxidation zoon was more conductive to gas-liquid and liquid-solid mass transfer,and the efficiency treating sewage would be much enforced in the same aeration condition.