回转式隔板絮凝池中增设折板工艺对低温低浊水的处理

Rotary Clapboard Flocculation Tank Process by Adding Folded Plate for Treatment of Low Temperature and Low Turbidity Water

合肥某水厂采用传统的回转式隔板絮凝池工艺,在冬季处理低温低浊水时,其混凝强度不够,导致沉淀池出水浑浊度高。为此,水厂在回转式隔板絮凝池中增设折板来改善水力条件。在絮凝池前2圈增设了平流式异波折板,后3圈中增设了平流式同波折板,折板夹角均为90°,折板间距为1 m。通过计算流体力学(CFD)模拟验证了增设折板可增加水流旋涡状态,也从实际生产运行中研究了增设折板对速度梯度和出水浑浊度的影响。结果表明:在回转式隔板絮凝池中增设折板可将GT提高2.2~3.9倍,能有效降低低温低浊水的出水浑浊度,降幅达31%,为老旧絮凝池优化改造提供一种思路。

Traditional rotary clapboard flocculation tanks are used in water plant in Hefei.Coagulation intensity of this process is not enough for low temperature and low turbidity water in winter,which resulting in high turbidity of sedimentation tank.Therefore,water plant added folded plates into conventional rotary clapboard flocculation,in order to improve hydraulic conditions.Horizontal-flow opposite folded plates and same wave folded plates,were added into the first two laps and the last three laps of rotary clapboard flocculation tank respectively.Folded plate angle was 90°,and folded plate distance was 1 m.By using computational fluid dynamics(CFD) numerical simulations,it was demonstrated theoretically that adding folded plate enhanced flow disturbance and vortex state.By studying on the effect of folded plate on velocity gradient and effluent turbidity during actual production,it was showed that adding folded plate into rotary clapboard flocculation tank increased GT value 2.2~3.9 times,effectively reduced the effluent turbidity of low temperature and low turbidity water in winter by 31%.It provides an idea for the optimization and transformation of those old flocculation tanks.