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(PV)and mixing performance between rigid Rushton turbine(RT)impeller and flexible RT impeller was analyzed with different flexible materials.The PV of rigid and flexible impeller did not have significant difference at the same agitation speed(N=60 r·min-1

PV=340 W·m-3 of rigid

PV=346 W·m-3 of flexible).Good mixing performance could be obtained by flexible impeller at θm=2 min

while the isolated mixing regions of rigid impeller still existed until θm=30 min.The mixing performance number of flexible was minimum(Ce=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.