Centrifugal Pump Impeller Cutting Experimental Study On Effects Of Law And The Number Of Leaves

The work is one part of the project, which is supported by scientific Research & Development fund, Gansu University of Technology.In the application of centrifugal oil pumps, we often meet the problem that is the offset in their performance parameters, or flow rate and pressure in processes can't satisfy the design and user's requirement. This requires that the performance parameter of pumps is revised by using the least effort or by modifying the least flow elements geometry, and results into energy saving. Cutting the impeller of pumps is a convenient and economical method for this purpose.Nowadays, the affinity law of impeller trim for the centrifugal water pumps is applied to impeller trim for the centrifugal oil pumps. Because the influence of the viscosity in the law is not considered, the viscosity will lead to large error. Up to now, there is no research on the affinity law of impeller trim for the centrifugal oil pumps.The centrifugal oil pump of type 65Y60, finalized by the former Ministry of Machinery-Building of China is used as a model, which is widely utilized in oilfields and refineries. The affinity law of impeller trim for the pumps at various viscosity and the influence of number of blades on the law have been thoroughly investigated by experiments. Based on the findings of the investigation, the following conclusions should be made:[1] The affinity law of impeller trim for the centrifugal oil pump 65Y60 is obtained when handling water from the experiments.[2] The affinity law of impeller trim for the centrifugal oil pump 65Y60 is gained when pumping viscous oil.[3] The greatest error is 50% between the result given by the affinity law of U.S.A and that calculated by using the trim law issued in this work.[4] The trim exponents vary with the fluid viscosity and impeller diameter ratio at same time.[5] The influence of the number of blades on the affinity law of impeller trim for the centrifugal oil pump is obtained.[6] Head exponent of the impeller for the various number of blades changes when viscosity increases. When viscosity is less than 188cSt, head exponent approaches to 2. When viscosity more than this value, the exponent closes to 2.5.[7] Power exponent of the impeller for the different number of blades changes when viscosity increases. When viscosity is less than 188cSt, the exponent closes to 2.8~3. When viscosity more than 188cSt, it closes to 2~2.75.[8] Flow rate exponent of the impeller for the different number of blades approaches to 1. Efficiency exponent approaches to 0~ 1.