改进Intermig桨固液浆态搅拌槽的实验和CFD研究

摘要

改进Intermig桨已经被应用到国内的种分设备中，其在促进了氧化铝颗粒的悬浮和混合的同时，搅拌功率也得到大幅度降低。采用计算流体力学和水模型实验相结合的方法研究改进Intermig桨固液搅拌体系中的流场、固含、云高度、临界悬浮转速以及功率消耗情况。与标准的Intermig桨相比，改进后的Intermig桨改善了槽内循环流的发展，促进了颗粒的悬浮，功率消耗也得到幅度降低。桨叶离地距离越低越有利于颗粒的悬浮与分散，并采用功率判据得到了颗粒悬浮的临界搅拌转速，同时采用数值模拟预测的结果与实验结果吻合较好。%The improved Intermig impeller has been used in the seed precipitation tank in China, which could enhance the mixing and suspension of Al(OH)3 particles and the power consumption declined largely. The flow field, solids hold-up, cloud height, just off-bottom speed and power consumptions were investigated in solid-liquid mixing system with this new type of impeller by CFD and water experiment methods. Compared with the standard Intermig impeller, the improved one coupled with specially sloped baffles could promote the fluid circulation, create better solids suspension and consume less power. Besides lower impeller off-bottom clearance is good for solid suspension and distribution. The just-off-bottom speed was also determined by a power number criterion. Meanwhile, the predicted results were in good agreement with the experimental data.