Study On Dynamic Cleaning Technology Of Granular Agricultural Products

Cleaning process is an important part of agricultural products processing,and its effect directly affects the processing quality of agricultural products.This session mainly to remove the surface of agricultural products,sediment,pesticide residues,eggs and other impurities,for the subsequent processing or direct consumption of clean and quality products.In view of the current granular agricultural products washing machine has the disadvantages of incomplete cleaning,large amount of water consumption and large damage to the substrate of the cleaned material.This paper presents the idea of dynamic cleaning,to ensure the efficiency of cleaning,to make cleaning of agricultural products cleaner.The dynamic cleaning machine designed and studied in this paper adopts the scheme of vibration conveying and low pressure continuous water jet cleaning.The method of FLUENT_EDEM coupling was used to simulate the granular agricultural products cleaning process and optimize the relevant parameters.The main work and achievements of this paper are as follows:(1)The kinematic equation of the vibration conveying mechanism was analyzed,and the motion equation of the vibration groove was established.The movement of agricultural products particles in the vibrating trough was analyzed,and the mathematical model of single particle rotation and movement was established.Analyzing the influence of relevant parameters on the particle rotation angle,the vibration frequency had the greatest influence on the angular displacement of the particles.Selecting proper angular velocity can increase the degree of particle rolling.(2)The structure parameters of water jet nozzle was studied,and the flow field characteristics of the nozzle was studied by numerical simulation of nozzle outflow field through FLUENT software.Analysis of water jet nozzle in the incident angle,target distance,pressure and flow and other factors change,the corresponding flow field characteristics.It was initially determined that when the cleaning target distance of thisnozzle was 200 ~ 300 mm and the incident angle of water jet was 60 °,the jet velocity and pressure on the wall surface were the highest,and the jet cleaning effect was the best.(3)The numerical simulation of the cleaning flow field was done,the simulation results show that the cleaning flow field pressure in the longitudinal dislocation layout was more uniform and the number of nozzles used is relatively less.The vibration transport model of cleaning equipment and the grain and dust particle model of agricultural products were established based on EDEM.(4)On the premise of the determination of the amplitude,the form of the nozzle and the distance of the cleaning target,the orthogonal simulation test of four factors and three levels was designed by using the cleaning rate as the objective function.The influence of the vibration frequency and initial angle,the inlet pressure and the direction angle of the nozzle on the cleaning rate were discussed.The simulation results show that the inlet pressure and the direction angle had the greatest influence on the washing rate,while the vibration frequency and initial angle of the vibratory slot have little influence on the washing rate,and there is the best nozzle orientation and vibration frequency.The optimal horizontal combination of this test was that the vibration frequency of the vibrating groove was 3 Hz,the vibration direction angle was 36°,the inlet pressure was 0.7MPa and the angle of water jet was 60°.In this paper,the particle vibration cleaning technology of agricultural products was studied.Firstly,the movement of particles in cleaning was analyzed by theoretical deduction.The numerical simulation of the cleaning flow field was carried out,and then the cleaning process was simulated by the multiphase flow coupling method.Finally,the design and experimental verification of the test rig were carried out.The simulation results were consistent with those of the bench test.The research results could be used to design and optimize the related equipment.