Simulation Of Grain Cleaning Based On CFD-DEM Coupling

Soybean harvesting will consume a lot of human and material resources.At present,China is facing the shortage of agricultural workers and low quality problems.Agricultural mechanization has become the development direction of modern agriculture.At present,due to the mountainous terrain in South China,most of the harvesting operations in hilly areas use the traditional manual harvesting method,which is characterized by high labor intensity and low harvesting efficiency,easy to delay agricultural time and great indirect loss.Therefore,to adapt to the development of small-scale agricultural machinery harvesting equipment with scattered cultivation area in China has become a practical problem to be solved urgently.Its development speed will be related to the development process of Agricultural Mechanization in China and has a positive significance for the promotion of Agricultural Mechanization in China.Cyclone separator is an important part of small agricultural harvester.As a cleaning device,because of its simple structure,convenient maintenance and being able to adapt to the harsh production environment,it is widely used in small agricultural harvesters in the agricultural field,but also has the disadvantages of cleaning loss and power consumption.This paper discusses the structure of the cyclone separation cleaning device and the optimization of the speed conditions of the feed inlet and the discharge outlet,and the research on the influencing factors needs to be further strengthened.In this paper,the numerical simulation technology coupled with fluent edem software is used to simulate the non bucket cyclone separator,and the influence of single factors such as speed and structure on the cleaning performance of the cyclone separator is studied.The results show that the speed of the inlet and the outlet have an important influence on the cleaning performance,and the diameter of the separator,the diameter of the outlet,the height of the cylinder and the height of the cone have some influence on the cleaning performance,of which the diameter of the outlet is the most important.In order to minimize the power consumption,reduce the production cost and ensure the cleaning performance,this paper takes the feed inlet speed of 2 m / s as the fixed value,and discusses the influence of other five factors on the cleaning efficiency,impurity content and loss rate of the cyclone separator.The analysis of data results by range analysis method shows that the primary and secondary factors affecting cleaning efficiency are as follows: velocity of trash discharge outlet > diameter ofdischarge outlet > diameter of separating cylinder > height of conical cylinder >height of cylindrical cylinder.The optimal scheme of simulation test is: the velocity of discharge port is 18 m / s,the diameter of separation cylinder is 160 mm,the diameter of discharge port is 80 mm,the height of cylinder is 220 mm,and the height of cone cylinder is 90 mm.Finally,the optimal parameters are obtained: cleaning efficiency is85.28 %,impurity rate is 0.04 %,loss rate is 0,and the data result is the optimal cleaning index of all experimental groups.It provides a numerical test method of saving manpower,material and financial resources for the design of cyclone cleaning device on small agricultural harvester,and provides a reference for its structural design.