Study On Gas-solid Two-phase Flow And Wear Properties In A Sandblasting Machine

As a common mechanical cleaning equipment using gas-powered sand particles,sandblasting machines are widely used in petrochemical,machinery and civil engineering industries.The sandblasting machine uses compressed air as power to form a high-speed jet to spray the abraisive material to the surface of the workpiece,to achieve the purpose of altering the mechanical properties of the surface.The solid sand of the sandblasting machine usually uses silica sand.The sand enters the pressurized tank from the storage space under certain pressure conditions,and moves inside the tank pushed by the compressed air.Numerous sand particles will cause varying degrees of impact on the wall of tank.The material on the surface of the tank will become fatigued and fractured and form pitting and spalling,which leads to wear and even failure of the sandblasting machine.This paper selected the automatic feeding sandblasting machine commonly used in petrochemical enterprises as the research object,and used a transparent glass sand blasting machine model to conduct particle movement observation experiments to obtain the particle velocity distribution on the observation section.By implenting EDEM-Fluent coupling method,the solid two-phase flow field in the sandblasting machine was calculated,and the influence of some factors on the particle movement was analyzed.Finally,based on the principle of orthogonal experimental design and the wear model,the influence of each factor on the total wear volume and the relative wear of each part was analyzed.The specific work of this paper is as follows:(1)The particle movement observation experiment was carried out on the glass transparent sandblasting machine model,and the experimental principle,experimental device and specific steps of the experiment were introduced.The the radial velocity and axial velocity distribution of the particles on the observation section and different observation lines were obtained,and influence of different particle sizes and observation sections on particle velocity distribution was analyzed,providing verification for numerical simulation results.(2)A three-dimensional model of the internal fluid domain of the sandblasting machine was establish by Solidworks and the computational grid was created by ANSYS ICEM CFD.Based on the EDEM-Fluent coupling method,the gas-solid two-phase flow field inside the sandblasting machine was simulated.Pressure contours and velocity vector diagrams of the tank and different cross-sections were drawn,and particle motion and collisions laws were obtained.The influence of particle size,particle density and inlet pressure on the velocity of particles in the tank and the number of collisions with the wall was analyzed.(3)The simulation scheme was designed based on the orthogonal experiment and the Archard wear model was introduced.The influence of the particle size,particle density,particle shear modulus,particle initial accumulation height and inlet pressure on the total wear volume was studied,and the combination of factors with the smallest total wear volume was obtained.The wear position of each part of the sandblasting machine and the the wear volume of each part as a function of time were studied,and the influence of each factor on the relative wear of each part was analyzed.