新型多叶轮潜水搅拌机流场特性

为提高搅拌机搅拌效果,针对各种形状的污水处理池,设计出系列新型多叶轮潜水搅拌机.文中基于ANSYS Fluent 15.0,对2种新型多叶轮潜水搅拌机搅拌流体进行计算,展开深入研究.结果表明:新型双向潜水搅拌机和新型双层潜水搅拌机搅拌水池内流体有效轴向推进距离分别是同叶轮的传统潜水搅拌机的2.0倍和1.8倍,池内流体平均流速分别为0.194 m/s和0.215 m/s,与传统潜水搅拌机搅拌流体平均速度0.203 m/s接近.新型双向潜水搅拌机池内最大速度沿轴向分布呈现马鞍形分布,且流体速度差较大,仅有73.2%流体的流速大于0.050 m/s,且低速区存在于水池中上部,其更适用于狭长且不深的水池.新型双层潜水搅拌机搅拌水池内流体最大速度分布沿轴向呈现双曲线递减分布,78.71%流体的流速在0.100~0.300 m/s,池内低速流体仅占1.55%.故新型双层潜水搅拌机和新型双向潜水搅拌机搅拌性能明显优于同叶轮的传统潜水搅拌机.研究结果可为潜水搅拌机的实际工程应用提供参考.

Flow filed characteristics of new-type multi-impeller submersible mixer

To improve the mixing effect of a submersible mixer, a series of new-type multi-impeller mixers were designed for sewage treatment pools in various shapes. Based on CFD software ANSYS Fluent 15.0, the flow field of two new-type multi-impeller submersible mixers was studied in this paper. The results show that the effective axial propulsion distances in the new-type two-way submersible mixer and the new-type two-impeller submersible mixer are 2 times and 1.8 times that of the traditional mixer, and the average velocities of the fluid in the pool are 0.194 m/s and 0.215 m/s, respectively, which are close to the average velocity of 0.203 m/s in the traditional mixer. The maximum velocity curve induced by the new two-way submersible mixer is saddle-shaped, and the velocity difference is greater, only 73.2% of the fluid in the pool is with a velocity higher than 0.050 m/s, and the low-velocity zone is in the middle and upper part of the pool. The maximum velocity curve generated by the new-type two-impeller submersible mixer is in a hyperbolic decreasing shape. 78.71% of the fluid in the pool is in a velocity between 0.100 and 0.300 m/s, and the low-velocity zone accounts for 1.55% of the water body in the pool. Thus, two new-type mixers designed are obviously better than the traditional mixer in performance. The results can provide a reference for practical engineering application of submersible mixers.