CAST反应池底污泥均衡化技术及设备配置

针对现有CAST反应池中存在的池底污泥的流动性差、沉降快，沉淀后污泥分布不均、部分区域污泥沉积板结、污泥难以持续排出等问题，在实地勘察的基础上，从污泥的自有特性、生存环境、运作方式和流态模拟等多个方面加以全面研究，提出对池底污泥均衡化的改造方案，并设计出相应的所涉设备配置与布局方案。最后，还利用CFD软件Fluent对所提方案进行流场模拟分析、对比与优选。结果表明，所有区域的流速都大于0.1 m·s-1，使得污泥不沉降，采用循环环流布置比散射状流态布置的污泥流速更大，能量损耗更少，可优先采用循环环流的布置方法。

Equalization technology and device configuration scheme for sludge at bottom of CAST reaction tank

There have been some problems with CAST reaction tanks, such as poor fluidity and fast settling velocity of the sludge at the bottom of tank, uneven distribution after precipitation, partial sludge deposition hardening, unsustainable sludge discharge, and so on. In order to solve these problems, and on the basis of an on-the-spot investigation, for this article we comprehensively studied the characteristics, living environment, operation mode, and flow pattern simulation of the sludge. Transformation schemes for equalization of the sludge in the bottom of the tank were put forward, and the corresponding equipment configuration and layout plan designs were presented. Finally, the Computational Fluid Dynamics software Fluent was used to simulate and analyze the flow field of the proposed scheme. The results show that the flow rate of almost all areas was greater than 0.1 m·s-1, so that the sludge was not subject to settlement. With a circulation arrangement pattern, the sludge flow rate is larger and the energy loss less, than that with a scattered flow pattern. For this reason, the circulation arrangement pattern is preferred.