Axial flow pump impellers - effects of pump design parameters on its performence

AXIAL FLOW PUMP IMPELLERS-EFFECTS OF PUMP DESIGN PARAMETERS ON ITS PERFORMANCE SUMMARY Key Words : Axial Flow Pump, Pump Design Parameters, The Effect Of Its Performance. The effects of design parameters of axial flow pump impellers on its performance are experimentally investigated. Theoritical studies consist of general theory of turbo machinery, regaining the tangential velocity energy of pump, investigating the effect of number of impeller blades and open and closed type axial flow pump impeller. In the experimantal study, four axial pump impellers were designed and constructed. The stator and other parts of the pumps employed in the experimental studies are standard and in these experiments, the rotational speed of the pump motors are 1000, 1500 and 2000 rpm. For the experimantal studies of regaining of tangential velocity energy of pump, the impellers with three and four blades were tested with and without guied vane. As a result, the efficincy improvement upto %4 using guied vanes has been observed. The best efficincy is obtained at 1000 rpm using guide vane with four blade impeller as %65. For the experimental studies of the effects of number of blades on pump effciciency, impellers with three and four blades is used. The experiment results showed that the efficinecy can be increased by upto %3 using four blade impeller with respect to three-blade impeller, and the best efficiency is obtained at 1000 rpm using four blade impeller as %64. For the experimental studies for open and closed type impeller, the closed type impeller is tested and the results are compared with the previous results for open type impeller. In these experiments, while using open type impeller resulted in %2 more efficiency than using closed type impeller at 1000 rpm, it gave same result at 1500 rpm and %3 less efficiency at 2000 rpm. The last experimental studies consist of opening two channels through the two of the four blades of the impeller. No pump efficiency increase has been observed using them. One of the most important challenges obtained in this study is that when the flow rates decreases, shaft moment decreases with using guide vane. The oppsite effect is observed without guide vane, which is a known fact. xu