Design Simulation And Experiment Of Stripping Apparatus With Air Suction For Buckwheat

Buckwheat has high nutritional value and medicinal value.It is planted in a large area in my country and has a strong market demand.It is an important part of the world’s rain fed crops.On a buckwheat plant,when the grains at the bottom of the plant are mature,the grains in the middle of the plant may be immature,and there are still buckwheat flowers on the top of the plant,and the whole plant’s grains show different mature states;when the buckwheat grains are fully mature,the external environment is slightly If there is disturbance,the kernels will fall off.The special maturation process of buckwheat makes mechanized harvesting of buckwheat difficult,and the existing grain combine harvesting equipment harvests buckwheat,the harvest effect is not good.In order to solve the problem that the existing grain combine harvesting equipment is difficult to adapt to the harvest characteristics of buckwheat,a stripping apparatus with air suction for buckwheat was developed.A combination of theoretical analysis,parameter calibration,Fluent-EDEM coupling simulation and bench test.Feeding velocity,inlet air-flow pressure and cylinder speed were selected as impact factors,harvest rate and splash loss rate were taken as evaluation indexes for experimental study.This paper include mainly several research content as followings:(1)Calibration of interspecific contact parameters of buckwheat grain model.The discrete element model parameters that have a significant impact on the simulated stacking angle are screened out,and a regression model is established.Taking the actual stacking angle as the target,the optimal value is obtained,that is,the static friction coefficient of buckwheat-buckwheat is 0.24,and the rolling friction coefficient of buckwheatbuckwheat is 0.05.The buckwheat-steel recovery coefficient is 0.44.The simulation verification test is carried out under the calibrated parameters.The relative error of the simulated accumulation angle and the actual accumulation angle is 0.91%,which shows no obvious difference,which indicates that the simulated parameters of the calibrated discrete element model of buckwheat are accurate and reliable.The design of the device provides a basis.The study can provide reference for the related design of the stripping apparatus with air suction for buckwheat.(2)The design of the stripping apparatus for buckwheat.The design plan of the stripping device was determined.It was introduced that the working process of the stripping apparatus with air suction for buckwheat.The process of buckwheat feeding and threshing was analyzed.The structure and parameters of the key working parts of the stripping device was designed.(3)Motion simulation of buckwheat grains.The data coupling method of Fluent-EDEM software was used to study the movement characteristics of the buckwheat grain flow in the stripping apparatus.(4)Bench test of the stripping apparatus with air suction for buckwheat.Using a three-factor three-level center combination test method,a quadratic regression model with the feeding speed,inlet air-flow pressure,and drum speed as the test factors,and the buckwheat harvest rate and splash loss rate as the evaluation indexes for experimental study was established.The best combination of parameters was cylinder speed of 500 r·min-1,inlet air-flow pressure of 80 Pa,feeding velocity of 0.5m·s-1.Harvest rate was 86.37 % while splash loss rate was9.23% under this optimal parameter combination.