Simulation And Experiment On Castor Shelling Process

Castor has great development and application value,and the shelling effect of castor directly affects the quality of processed products.At present,the shelling rate of castors is low and the damage rate is high.The fundamental reason is that the shelling machine lacks the necessary theoretical guidance.The parameter design of key parts of shelling is related to the shelling process.Therefore,it is of great significance to study the shelling process of castors.In this paper,the physical and mechanical characteristics of castors were studied,the finite element method was used to analyze the fracture law of a single castor under compression test,the main parameters required for discrete element analysis were determined,the discrete element shelling process analysis model was established,the movement law of material groups during shelling process was studied,and a test rig for verification was designed.The main research contents are as follows:(1)The sphericity,water content and breaking force of typical castors were tested and analyzed.The triaxial size of castors of different varieties were measured and calculated sphericity.The top and middle direction compression tests of castors with different varieties and different water contents were carried out,the mechanical properties were analyzed,and the shelling stage was divided.(2)The rupture rule of a single castor under compression test was studied.Tongbi 11 was taked as the sample,the loading force at each breaking stage was measured by compression test,and the fracture law was analyzed by finite element method and verified by experiment.It provided a reference for the establishment of shelling model.(3)The key parameters for discrete element analysis of castors were determined.The friction coefficient,collision recovery coefficient and angle of repose of castors of varieties 1987 and Tongbi 11 were measured,and discrete element simulation test was conducted with angle of repose as the response value to obtain the optimal parameter combination.The angle of repose simulation test was conducted with this set of parameters,and the simulation results were compared with the measured values to determine the key parameters.(4)The group movement law of castors during shelling was studied by using the principle of rubbing and pressing shelling.The discrete element shelling analysis model was established by taking the Tongbi 11 as the sample.The simulation test was carried out with rotation speed,shelling clearance and filling amount as factors,and the influence of each factor on the maximum pressure,maximum speed,inner drum stress and shelling rate was analyzed by response surface method.According to a group of experiments,the shelling stage was divided,and the material distribution,movement and stress in each stage were analyzed.(5)The movement rule of castors population during shelling was verified.Based on the discrete element simulation shelling model,a castor shelling test bed was designed,and the results of material distribution and shelling rate tests in the simulation were compared.The rotation speed,shelling clearance and filling amount were taked as factors,shelling rate,damage rate and productivity were taked as indicators,the working parameters of the test bed were studied,and the optimal combination of shelling rate was compared with the simulation results.This study provides theoretical support for the design of castors shelling machine and its key components,provides reference for the development of high-efficiency and low-consumption castor shelling machine,and provides a new method for agricultural material shelling research.