Analytical and experimental assessment of screw centrifugal pump at improving its design

Abstract

Purpose. Development of analytical and experimental assessment of screw centrifugal type pump at a design stage, which permits defining more precisely its power and cavitation characteristics. Methodology. To achieve the above-mentioned purpose, the technique that includes the following possibilities was developed: make the list of changes which increase the efficiency of the existing pump; quickly and with high precision to estimate influence of certain constructive and/or regime changes on efficiency of the existing pump without difficult flow calculations; determine the need to develop a new pump, if all the changes of the existing pump did not give a positive result; determine changes influence on cavitation properties of the existing pump; calculate the efficiency dispersion during hydraulic tests of the modified pump. Findings. During the research, an analytical and experimental technique which permits determining increase in the pump efficiency quickly and with high precision at the change in pump design and/or operating mode was developed. The developed technique determines how all changes in the existing pump influence its anti-cavitation properties. The above mentioned technique also allows calculating the efficiency dispersion during hydraulic tests of the modified pump. The technique determines the need to develop a new pump, if all the changes in the existing pump did not give a positive result. The use of the presented calculation technique, at a design stage, allows estimating the efficiency of the developed pump more precisely. The developed technique allows increasing the efficiency assessment accuracy and cavitation characteristics of low-flow high-speed screw centrifugal pump. Originality. During the research, new empirical dependences were obtained that permit defining more precisely power and cavitation characteristics of low-flow high-speed screw centrifugal pump. Practical value. The presented technique at a design stage allows estimating the developed pump efficiency more precisely. Due to this, it is possible to reduce the time for pump development and its development tests.