Abstract: The flocculation is one of the important in water treatment process，i.e. mixing-flocculation-sedimentation. Based on flocculation mechanism，a stirred-reaction tank and a stirrer are designed to provide suitable hydraulics. Flow distribution in the tank was simulated by computational fluid dynamics（CFD） technique. About 20% of flocculants consumption is saved by using the stirred tank；secondary pollution induced by excessive flocculants is avoided，and the outflow quality is improved.

Key words: water treatment, flocculation, stirred, computational fluid dynamics（CFD）

摘要： 絮凝反应是原水预处理工艺（混合-反应-沉淀）的重要环节，对整个工艺过程的水处理效果影响极大。本文针对絮凝反应过程中絮体颗粒生长所需的水力学条件，采用计算流体力学（CFD）软件分析了所设计搅拌絮凝反应池运行的可行性，通过控制絮体颗粒生长的流场，使絮体在其中可以生长至合适的尺度。研究结果表明，采用优化之后的反应设备，可以节约絮凝剂用量约20%，降低了生产费用，避免过量絮凝剂对水体造成的二次污染，并且提高了出水效果。

关键词: 水处理, 絮凝反应, 搅拌, 计算流体力学