Research And Numerical Simulation Of Rotary Valve With Dropout Box For Pnenumatic Conveying Systems

The extensive use of pneumatic conveying technology has further promoted the development of modern industry.As one of the most commonly used continuous feeders in pneumatic conveying systems,the rotary valve can continuously and evenly feed the materials in the silo into the conveying pipeline.The rotary valve with dropout box is used as a transitional connection device between the rotary valve and the conveying pipeline,and the movement characteristics of the material within it directly affect the subsequent conveying characteristics.Based on this,this thesis is based on the "drop-through" rotary valve with dropout box,and uses CFD-DEM coupling numerical simulation method to focus on the movement characteristics of gas-solid two-phase flow in the rotary valve with dropout box.The main research contents are as follows:(1)In view of the structural differences of the rotary valve with dropout box,the three-dimensional models of "drop-through","bell-mouth" and "tilt" rotary valve with dropout box were established,and the mesh was divided.Then the models were imported into Fluent software and EDEM software respectively,and the relevant parameters were set: The physical model,material parameters,contact parameters,generation mode and generation rate of pea particles were set in EDEM software.The solution model,algorithm,boundary conditions and relaxation factors are set in the Fluent software.Finally,the coupling parameters are set through the coupling connection window,and then the coupling simulation setting is completed,and the coupling simulation is started.(2)In view of the above coupling simulation,a total of 6 kinds of rotary valve with dropout box installation schematics were established in this thesis,and 7 groups of simulation experiments were developed.(3)The theoretical calculation and simulation experiment were used to compare and analyze the leakage amount of rotary valve.It is pointed out that the difference of the structure of the rotary valve and the operating pressure seriously affect the change of the air leakage.(4)By using CFD-DEM coupling method,the flow diagram,velocity cloud diagram and particle motion state diagram of the gas phase flow field obtained after processing can not only observe the flow characteristics of the gas-solid two-phase flow in the dropout box from the macroscopic perspective,but also track the movement trajectory of particles from the microscopic perspective.In this thesis,CFD-DEM coupling numerical simulation method was used to conduct simulation research on the shape,height,operating pressure,rotation direction of the rotor of the rotary valve and the installation direction of the rotor shaft relative to the horizontal conveying pipe of the rotary valve with dropoutbox as variables,so as to explore the movement characteristics of the gas-solid two-phase flow inside the rotary valve with dropout box.So as to provide a theoretical reference for the selection of rotary valve with dropout box.