液-液射流搅拌提高热水解污泥混合性能分析  

Analysis of liquid-liquid jet agitation improving mixing performance with thermal-hydrolyzed sludge

作　　者：曹秀芹[1] 丁浩[1] 蒋竹荷 袁海光[1] 

机构地区：[1]北京建筑大学城市雨水系统与水环境省部共建教育部重点实验室,北京100044

出　　处：《环境工程学报》2018年第1期316-323,共8页Chinese Journal of Environmental Engineering

基　　金：北京市教委科技重点项目暨北京市自然科学基金资助项目(KZ201310016017);北京建筑大学研究生创新项目资助(PG2017011)

摘　　要：在厌氧消化反应器中,机械搅拌是广为应用的搅拌方式,但机械搅拌在运行过程中存在设备维修困难、能耗高等问题。基于前期的研究,利用Ansys 17.2软件平台,构建3 000 m^3液-液射流搅拌厌氧消化反应器1∶1仿真模型,为考察液液射流装置对热水解污泥在反应器内的搅拌混合效果,模拟得出速度云图、速度矢量图、剪切速率图以及死区分布图,并对搅拌性能、搅拌机理进行分析。结果表明:流场区域流速范围0~1.50 m·s^(-1),剪切速率范围0~200 s^(-1);依据斯托克斯定律计算出该流场中沉降速度阈值0.30 m·s^(-1),低于该速度值的部分形成死区,死区主要分布在流场中心区域,其体积为600.88 m^3,占总体积20.58%;相对于流场中心区域,流场内其他区域流速均值为0.60 m·s^(-1),得到较好的搅拌混合。In the anaerobic digestion reactor, mechanical agitation is a widely used method of mixing, but there are difficulties in equipment maintenance and high energy consumption during the operation. Based on the previ- ous research and Ansys 17.2 software platform, 1 ： 1 simulation model was constructed by simulating 3 000 m3 anaerobic digestion reactor, equipped with liquid-liquid jet device in a sludge centralized treatment station. Velocity vector, shear rate, and dead zone profiles were used to investigate the mixing effect of liquid jet device for thermal-hydrolyzed sludge. The mixing performance and stirring mechanism are also analyzed. As a result, the velocity range of the flow field is from 0 to 1.50 m· s-1 and the shear rate range is from 0 to 2.00 s-1 The sed- imentation velocity threshold is 0.30 m· s-1 according to Stokes＇ s law and the volume of the part below this velocity is 600.88 m3 , reaching 20.58% of the total volume. Compared with the center of the flow field, the mean velocity of other regions is 0.60 m · s-1 and the mixing is much better.

关 键 词：热水解污泥 厌氧消化 CFD模拟 搅拌性能 流场分析 

分 类 号：X705[环境科学与工程—环境工程]