Simulation Study On The Cleaning Process Of Large Feed Grain Harvester

The cleaning process is an important workflow in the grain harvesting operation,and its performance directly affects the quality of the grain harvest.This paper takes the cleaning process of a large-feed grain harvester as the research object,and the harvested crop is wheat.To reduce the impurity content of the cleaning and control the loss rate,the typical wind sieve cleaning process is studied.For the main content of this article:(1)The main working parts in the cleaning process are the wind speed fan and the vibrating screen.By simplifying the model,analyzing the motion mode of the vibrating screen,drawing a schematic diagram of the moving mechanism,establishing a physical model of the cleaning fan,and using CFX software to analyze the fan,The law of internal flow field velocity and pressure distribution,and the law of fan outlet wind speed at different impeller speeds are obtained.(2)The main components of the cleaning materials include wheat grains,short stalks,long grass,and other light impurities.It is clear that the main impurities in the cleaning process are short stalks.The material properties and motion characteristic parameters of the cleaning material particles are relatively complicated.The material properties and motion characteristic parameters of each component in the cleaning material are measured through a series of measurement experiments.During the experiment,the suspension speed of wheat grains and short stalks overlapped,which caused the main difficulty in the cleaning operation.(3)The CFD-DEM coupling method is used to simulate the air sieve cleaning process,and the API program coupling results are used to couple EDEM and Fluent.The flow field law is simulated in Fluent,and the particle movement is simulated in EDEM.Coupling analysis Simulate the movement trajectory of particles in the airflow field and its speed change law.(4)Analyze a variety of influencing factors in the cleaning process,select the appropriate level with the impurity rate as the test index to arrange orthogonal tests,and determine the major and secondary order of the impurity rate in the cleaning process by different factors through statistical analysis,Obtain the plan with the lowest impurity rate,and check whether the loss rate under the plan meets the requirements of the operation.