Solid-liquid Two-phase Flow And Wear Characteristics Of Dense Fine Particles Transported By Centrifugal Pump With Open Impeller

At present,the proportion of petrochemical,marine mineral mining,urban sewage treatment and other particle transportation projects in the entire industry has increased significantly;at the same time,centrifugal pumps are a relatively large part of fluid transportation equipment.When the centrifugal pump is transported high concentration particles,since the presence of high-concentration particles changes the internal flow of the centrifugal pump,and the particles collide with the overflow member,resulting in the delivery performance and life of the centrifugal pump,at the same time,high concentration particles The mechanism in the rotational flow has not been fully disclosed This paper uses numerical simulation methods to study small flow 0.6Q)high concentration(particles concentration C≥10%),under fine particles(particle size d<0.5mm),the particle concentration and particle size on the internal and external characteristics of the open centrifugal pump And through external characteristic experiments,the accuracy of simulation is verified.The wear characteristics of the open centrifugal pump were then studied using the DDPM model,and the comparative analysis was carried out with the experimental results.Finally,the partial wear of the impeller was characterized by a super-pendant microscope.A reference is provided for the design and wear performance improvement of the thickness of the thick particles soil fixation.The main contents of this paper are as follows:(1)By analyzing the applicable scope of different solid-liquid two-phase flow control equations,simplify the particle force and improve the control equations based on assumptions.Through the particle-wall model and the Fluent built-in particle-wall model proposed by the predecessors,the centrifugal pump with open impeller was used for numerical simulation of DDPM,and the four groups of particles were verified through the test bed for solid-liquid two-phase flow of dense and fine particles built applicability of the wall model,namely: the first group,Fluent 18.0 the built-in particle-wall rebound model and wear function;the second group,G&T the proposed particle-wall rebound model and the E/CRC proposed particle-wall wear model;the third group,G&T the proposed particle-wall rebound model and the Oka proposed particle-wall wear model;the fourth group,the built-in particle-wall rebound model and the particle-wall wear model.The wear position of the first set of models(mainly in the middle and upper pressure surface)and the wear rate are close to the test,namely the first set of models is selected.(2)Carry out three-dimensional modeling of the full flow field of the open centrifugal pump,meanwhile carry out mesh division and grid independence verification for the inlet and outlet pipes,volutes and impellers,and use the Mix model in Fluent to study the small The influence of particle size and particle concentration on the internal and external characteristics of an open centrifugal pump at flow rate,and the accuracy of this model is verified based on the external characteristics of the experiment.Under small flow,the effects of high concentration and particle size on external characteristics are similar,and the effects of internal characteristics are also different.(3)Study the main factors of wear of three split centrifugal pump with open impeller(like flow,particle size and particle concentration),and analyze the influence of different parameter changes on the wear of different parts of the open centrifugal pump,that is,the change of parameters,on the pressure surface(The influence of the wear area and wear rate of the main pressure surface and secondary pressure surface),suction surface(primary suction surface and secondary suction surface),impeller,volute and other parts.The wear rates and wear areas at different locations vary differently with the properties(flow rate,particle size,and concentration).(4)Through a set of concentration(C=10% 、 15% 、 20% 、 25%)abrasion experiments,analysis of the concentration change on the impact of the impeller on the wear area of different parts,Increasing concentration expands the wear area,and compared with the numerical simulation results,and the amount of wear was measured,and the main wear area of the impeller was used to characterize the main wear area of the impeller,The spherical particles feature a smooth wear positions.