四边形折流式膜生物流化床内填料浓度及液相流场特性研究

发布时间：2018-05-09 17:08

本文选题：粒子图像测速(PIV) + 生物流化床　；参考：《环境科学学报》2017年11期

【摘要】：针对研究开发的四边形折流式膜生物流化床,构建了气、固、液三相流可视化平台,应用取样法和激光粒子图像测速(PIV)技术剖析了不同进水流量和曝气强度组合对流化床内的填料浓度及液相流场特性的影响.结果表明,折流板上部形成的曝气死区,提高了升流区的填料浓度;折流板和导流锥形成的进水角度使流场冲击反应器底部的填料,提高了在低曝气强度下流化床的填料浓度,在实际运行过程可降低曝气能耗;四边形折流式膜生物流化床的结构特点导致填料与膜组件相互碰撞的概率增大,强化了膜污染的控制.曝气强度和进水流量的变化改变了液相的轴向返混强度和剪切力,进而改变了填料浓度,使气、固、液三相冲刷膜组件的作用增大,最终影响膜面传质系数和浓差极化边界层厚度,降低了膜污染.通过流化床结构的改变提高填料浓度和改善流场特性,为高浓度有机废水好氧生物的处理提供了一个研究方向.
[Abstract]:A visualization platform of gas, solid and liquid three-phase flow was constructed for the developed quadrilateral baffled membrane biological fluidized bed. The effects of different influent flow rate and aeration intensity on the concentration of filler and the characteristics of liquid phase flow field in fluidized bed were analyzed by means of sampling method and laser particle image velocimetry (PIV) technique. The results show that the dead aeration zone formed in the upper part of the baffle increases the packing concentration in the upflow zone, and the inlet angle formed by the baffle and the diversion cone causes the flow field to impact the packing at the bottom of the reactor and increases the packing concentration of the fluidized bed under the low aeration intensity. The energy consumption of aeration can be reduced during the actual operation, and the structural characteristics of the quadrilateral baffled membrane biological fluidized bed increase the probability of collision between the packing and the membrane assembly, and strengthen the control of membrane fouling. The change of aeration intensity and influent flow rate changed the axial backmixing strength and shear force of liquid phase, and then changed the concentration of filler, which increased the function of gas, solid and liquid three-phase scour membrane assembly. Finally, the film surface mass transfer coefficient and concentration polarization boundary layer thickness are affected, and the membrane fouling is reduced. By changing the structure of fluidized bed, the concentration of filler and the characteristics of flow field are improved, which provides a research direction for aerobic treatment of high concentration organic wastewater.
【作者单位】：四川理工学院过程装备与控制工程四川省高校重点实验室;
【基金】：四川省科技支撑计划项目(No.2014GZ0132) 自贡市科技局重点项目(No.2013X12,2016SF02) 四川理工学院创新基金项目(No.y2016011)~~
【分类号】：X703

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