Flow Regime And Mixing Performance Of Single Impellers

In this thesis,the performance of fluid structure,power number,circulation efficiency and mixing time was investigated in the stirred tank mounted with hydrofoil impeller(3H),concaved hydrofoil impeller(3CH)and three pitched-blade turbines which have different diameters.The experimental results show that the power numbers of 3H and 3CH was much lower than those of PBT,but 3H and 3CH were better than PBT on the circulation efficiency.For PBT the power number reduced as the impeller diameter increased.3H and 3CH both can provide high axial velocity at low power consumption,especially 3H,and the fluid structure was simple.The mixing time of 3H and 3CH were sensitive to the input power and increasing the input power can radically reduce the mixing time.In the tank with PBT stirring,the impeller with the minimum diameter consumes the least input power until it was interfered by the fluid structures.