Simulation Study On Conveying Process Of Venturi Feeder Based On CFD-DEM

Pneumatic conveying technology refers to the technology that air or other gases flow in the established pipeline route to transport material particles from the initial position to the destination position,which is widely used in industry,energy,agriculture,mining and so on.As a very important part of the pneumatic conveying system,the feeder is mainly used to transport the material particles into the conveying pipeline,so that the material particles can be mixed with the air flow.The Venturi feeder has the advantages of simple structure and convenient operation.Systematic discussion and research on its internal structure and motion characteristics are of great practical significance to improve its transportation performance.Based on the mechanism of pneumatic conveying,this paper uses the theoretical formula of pneumatic conveying Venturi tube to determine the diameter and length of the conveying tube,nozzle outlet diameter,nozzle length,receiving chamber diameter and length,mixing chamber diameter and length,diffusion chamber of the Venturi feeder,the length and other parameters are designed and calculated,and the optimal structure of the Venturi feeder is designed by the method of orthogonal experimental design.This paper firstly systematically sorts out and summarizes the research results of Venturi feeders at home and abroad,and clarifies the background and significance of this research,and then briefly introduces different types of pneumatic conveying systems and pressure-feeding systems.For the feeder,in order to satisfy the smooth conveying of materials,a pressure-feeding pneumatic conveying device and a venturi feeder are selected for conveying,the basic characteristics of the materials are analyzed,the working principle of the venturi feeder is introduced,and the venturi tube is conveyed by pneumatic force.Based on the theoretical formula of,the relevant structural parameters of the Venturi feeder are designed and calculated.Secondly,the three-dimensional model of the Venturi feeder was established by using Solidworks software,and the method of coupling EDEM software and FLUENT software was used to simulate and study the Venturi feeder of the pressure-feeding pneumatic conveying device for conveying wheat materials.Compare the real velocity distribution with the movement trajectories of wheat grains.After research,it is found that the position of the nozzle throat of the Venturi feeder has a stable high jet,which can transport the particles very stably.However,when the particles enter the receiving chamber quickly from the edge of the feeder,the particles deviate from the nozzle.The spray range moves to the upper and lower sides of the nozzle to form residues.Finally,the structure of the Venturi feeder is optimized and improved,the structure is improved to a rectangular tube structure,and the nozzle structure is improved to a gradient structure to avoid the phenomenon of material residues.The improved Venturi feeder is simulated by using the method of orthogonal experimental design.Taking the maximum wind speed of the flow field in the Venturi feeder as the test index,the wind pressure of the structure,the length of the nozzle and other four factors are carried out.Coupling simulation,and comprehensive analysis of the generated simulation data,thus determining the combination scheme that best meets the operating requirements,and verifying through simulation experiments,it is known that the method has good feasibility and good conveying performance.