Design And Study Of Polyurethane Rubber Sieve For Maize Mixture

Corn has become a major crop in China,because of its high yield,planting area is wide,the demand for corn combine harvesters increased.because the corn harvester works by snapping the form of picking Corn Cob,greatly improves the work efficiency and harvest period,and grain harvester directly collected corn also reduced the follow-up work long,in recent years the corn harvester has been widespread concern.The sieve plate of vibrating screen is an important part of the cleaning device.Different forms and materials of sieves both affect the screening performance of the cleaning device.The sieve plate is one of the key part of corn harvester,which directly affects the performance of the cleaning effect.Exploring new plate materials in the cleaning device in application,analysis of dispersion of particles on different sieves,researching the influence of the working parameters of the polyurethane rubber sieves on the screening performance,provide theory basic research not only for the polyurethane rubber sieve,but also provide reference for the subsequent optimization research.This article summarized the development status of the vibration sieve at home and abroad,analyzes the current development and application of the cleaning device,found that there have been no reports of polyurethane rubber sieve plate used in agricultural mixture cleaning device.Based on the measurement of physical parameters of polyurethane and particles,this artilce explores the changing rule of particle number of polyurethane rubber sieve plate and metal sieve plate in the cleaning device.The method of physical parameter measurement,numerical simulation and experimental system test is used to explore the change of particle number on polyurethane rubber sieve plate and the comparison with the dispersion of metal sieve plate.The effects of fan frequency,crank speed and mass of maize mixture feed on the cleaning performance of the cleaning device were discussed by orthogonal rotation test,the main research work was as follows:(1)Through the experiment to obtain the physical parameters of polyurethane and particles,and measure the physical characteristics of the maize mixture.The particle model of maize,corncob and corn stalk was obtained through EDEM,and shell model was built in Pro/E,and spherical particles were densely arranged and filled in EDEM.(2)Through CFD-DEM coupling simulation method,the simulation experiment is carried out,and the particles number of polyurethane rubber sieve plate is compared with that of metal sieve plate.The results show that the sieve surface of polyurethane rubber sieve is better dispersed.(3)The evaluation criteria for the quantitative dispersion of particles in the longitudinal zoning of two dimensional sieves were defined,and the movement trend and distribution of the particles of the sieve surface were obtained.The dispersivity of polyurethane rubber screen is 0.064,which is greater than that of metal sieve 0.049.(4)In order to verify the particles motion on the polyurethane rubber sieves,and the mass distribution of the particles in and out of the polyurethane rubber sieves.which is particles in polyurethane rubber sieve inside and outside the mass distribution.through the experimental system test,the practicability of the polyurethane rubber sieves was evaluated on the basis of the cleaning rate of maize and the loss rate of maize.The final results show that the cleaning rate of maize and the loss rate of maize of the simulation test of CFD-DEM polyurethane rubber sieves are 95.4% and 1.82%.The results of the simulation test and the experimental system results are almost identical.(5)In order to get the optimal parameters of polyurethane rubber sieve,selected loss rate of maize and cleaning rate of maize as the test target.Designated chooses the gas speed of Inlet of polyurethane rubber sieve,crank speed and mass of maize mixture fed as factor,using two orthogonal rotation combination design experiment to analysis the test data by Design-expert 8.0.6.When the polyurethane rubber sieve is fed to 5.50kg/s,the working parameters of the polyurethane rubber sieve are 13.29m/s of inlet gas speed and 273r/min of crank speed.