柔性桨强化高黏度流体混合的能效分析

引言搅拌混合操作广泛应用于化工、食品、冶金及环保等过程工业领域[1-4]。搅拌槽内物料的混合程度及其功率消耗是影响产品质量和设备作业效率的关键因素。当物料黏度较高时,搅拌槽内的流

Energy efficiency analysis for high-viscosity fluid mixing enhanced by flexible impeller

The mixing performance of stirred tank is usually low for high-viscosity laminar flow mixing system.In order to intensify mixing performance,isolated mixing regions were experimentally destroyed by flexible impeller.Power consumption and mixing time were measured with viscous glycerin as working fluid,together with the shaft torque method and acid-alkali visualization technology.Comparison of power characteristics(P_V)and mixing performance between rigid Rushton turbine(RT)impeller and flexible RT impeller was analyzed with different flexible materials.The P_V of rigid and flexible impeller did not have significant difference at the same agitation speed(N=60 r·min^-1,P_V=340 W·m^-3 of rigid,P_V=346 W·m^-3 of flexible).Good mixing performance could be obtained by flexible impeller at θ_m=2 min,while the isolated mixing regions of rigid impeller still existed until θ_m=30 min.The mixing performance number of flexible was minimum(C_e=2.9×10⁶)and mixing performance was optimal at N=120 r·min^-1.Compared with the rigid impeller,mixing performance of silicone rubber flexible impeller was improved by 52.8%,and the mixing performance of PVC and rubber flexible impeller was improved by about 51.1%、50.5%,respectively.