Investigation Of External Characteristic Of Mud Pump And Pump Casing Deformation

At present there are limits in the research on dredge pump’s design and dredging characteristic:(1) Dredge pump was designed mostly based on the water, not considering sediment, which resulted in quite differences between the design and the actual performance of dredge pump;(2) Dredge pump design performance is also difficult to meet with the whole soil complex and changeable conditions of rivers, lakes,and seas in China at the same time;(3) Dredge pump complex and harsh working conditions not only caused the pump shell wear, erosion and cavitation erosin, but also resulted directly in-the pump shell deformation, which was due to the great pressure difference between the inside and outside of the pump itself. They not only affects the pump’s dredging efficiency and operational safety, but also leads to the increase in energy consumption and reduces the service life of the pump. Therefore, studying dredge pump’s performance on different sediment particles (within the flow field and the external characteristics), and exploring the relationship between external characteristics and pump shell deformation, have the important theoretical and practical significances to increase the mud pump dredging efficiency and the safe operationIn the paper, based on1750m3/h dredger mud pump’s solid-liquid two-phase flow dredging conditions, simulating the internal flow field of mud pump using the FLUENT, analysing the particle concentration, the diameter and density on the dredge pump’s internal pressure field, and forecasting the pump shell deformation using ABAQUS were carried out. With Taguchi method to analyse the external characteristics of the sediment particle, discussing the relationship between the external characteristics and the pump shell deformation under dredging pump’s maximum load.The main conclusions are as follows:(1) Simulation of the pressure field shows that the peripheral wall and the side wall pressure of pump shell have some fluctuations, but the difference between adjacent peaks and troughs are less than0.1MPa; pump shell peripheral wall pressure increases along with the circumferential angle fluctuations rise; greater sediment particulate volume concentration and particle size, more obvious the pump pressure increases, with increase of particle density, the pump pressure increases slightly.(2) Maximum deformation of the pump shell occurs mainly in the axial direction a maximum cross-sectional, and is mainly the deformation of the axial direction of outer sheets; larger and smaller areas of pump shell deformation locate300°～30°,60°180°respectively; With increases in sediment particle concentration, particle size and density, pump shell deformation increases; and the influence order on pump shell deformation is the particulate’s volume concentration, particle diameter,s particle densities respectively.(3) Study on external characteristics of dredge pump shows:with the increase of sediment particle volume concentration, particle size and density, the dredge pump head and efficiency are both decreased, but shaft power is increased; Taguchi analysis finds:head-particle size, concentration> density (contribution ratio of69.86%,28.31%,1.84%); shaft power-particle size>density> concentration (contribution ratio were99.10%,074%,0.17%); efficiency-particle size> density> concentration (contribution ratio of65.35%,19.58%and15.07%).(4) The simulation on factors of sediment particles finds that, when dredge pump works at high head and efficiency, the pump shell deformation is small, which means that it can not noly enhence the efficiency in a certain degree, but also ensure the safe operation; meanwhile, under the maximum load conditions, the dredge pump head and efficiency significantly lower (14.62%and38.65%, respectively, compared with the clean water), the pump shell deformation is1.547mm, however it still in the range of safety design gap (2mm). For the operation of1750m3/h dredger mud pump on the conventional fine, coarse sand conditions, the pump shell deformation is safe within the design value.(5) Taguchi analysis method used in the data analysis of the paper shows that, the results can not only provide the roles of dredge pump external characteristics influencing factors, but also the quantitative data, which is proved to be more accurate and effective.