Multi-Physics Coupling Simulation Of Whitening Process Of Horizontal Iron Roller Spray Wind Rice Mill

The rice milling machine is one of the most important mechanical equipments in rice processing.The brown rice is rubbed or milled in the whitening room of the rice milling machine,and the surface skin layer is pulled off and erased,so that the brown rice is whitened.In this process,the process performance of the rice mill is very important,which directly affects the whitening effect of brown rice.However,the movement state of brown rice in the whitening chamber,the magnitude of the force and the situation of the airflow field in the whitening room are not clear,and it is difficult to accurately measure it.In this paper,the horizontal iron roller wind mill is taken as an example.The particle simulation software EDEM is used to simulate the movement of brown rice particles in the whitening chamber.The fluid dynamics software Fluent is used to simulate the airflow field in the whitening chamber.Using the EDEM-Fluent coupling simulates the jet milling process.The main research contents and conclusions are as follows:(1)The EMEM software was used to simulate the brown rice milling process.The movement state and force of the brown rice granules in the whitening room were analyzed.On the basis of this,the numerical simulations were carried out by setting the rotational speed of the different sets of rollers,spindles and other components,and the spacing between the rice screen and the roller.The influence of rotation speed and spacing on the whitening pressure of brown rice was analyzed.According to the analysis of the simulation results data,the following conclusions were drawn: when the rotation speed is lower than 1540r/min The faster the rotation speed,the smaller the whitening pressure of the brown rice is.When the rotation speed is higher than 1540r/min,the whitening pressure of the brown rice increases with the increase of the rotation speed;the whitening pressure of the brown rice is related to the rice sieve and The roller pitch is increased and decreased,and the fitting formula is given.(2)The EDEM and Fluent coupling were used to simulate the spray milling process.The simulation results were compared with the simulation results under the condition of no air blowing.It was found that under the condition of air blowing,the distribution of brown rice in the whitening room was more uniform and the force was more uniform;On the basis of this,by changing the speed of the blasting speed,the uniformity of the brown rice in the whitening room was compared under different blast conditions.It was found that when the blasting speed was 15m/s,the stress of the brown rice was the most uniform,and the blasting speed was The next 10m/s.(3)A brown rice model closer to the actual brown rice structure was established,that is,the double layer structure of the surface particles wrapped in the inner layer particles,and the adhesion between the different particles was set.The brown rice particle model was simulated by EDEM coupled Fluent to simulate the surface breakage of brown rice during the whitening process,and the variation of the number of bonded particles with time was obtained.This method provides a reference for the simulation of the process of peeling and shelling.