The Experimental Research On Discrete Element Analysis Parameters Of The Agaricus Bisporus Seeds And The Seed-metering Device Optimization

With the edible value and medicinal value of agaricus bisporus gradually being widely recognized,its market demand is also growing,so it also puts forward higher requirements for the cultivation and processing technology of agaricus bisporus.China’s current cultivation and processing of agaricus bisporus mainly relies on manpower,resulting in low work efficiency and high labor intensity,and the necessity of research on mechanized seeding equipment of agaricus bisporus is clarified.This paper summarizes the structural characteristics of a variety of seed-metering devices at home and abroad.Based on the characteristics of the cultivation of agaricus bisporus,the agronomic requirements of the sowing amount and the objective environmental conditions,the main research contents and directions are clarified.The material parameters and contact parameters of agaricus bisporus seed were determined and calibrated by actual test and simulation test.The seed-metering device test bench was manufatured and the paper established mathematical models through experiments.Based on the obtained mathematical model design and comprehensive experimentation,the optimal working parameters of seed uniformity were determined.The main research contents and conclusions of this thesis are as follows:(1)Determining and calibrating the material parameters and contact parameters of agaricus bisporus seed.Through actual experiments and simulation experiments,the material parameters of agaricus bisporus seed was measured and calibrated.The triaxial sizes of agaricus bisporus were 5.8mm,3.6mm and 3mm.The weight of 1000-grain was 58.23 g.The water content was 42.11%.The density was 1916kg/m3.The inter-species sliding friction coefficient is 0.4.The Poisson’s ratio was 0.305.The shear modulus is 5.07 Mpa.The inter-species collision recovery coefficient is 0.5,and the collision recovery coefficients of the seed-nylon and seed-Q235 were 0.36 and 0.45.The sliding friction coefficient of the seed-nylon and seed-Q235 both were 0.55.The rolling friction coefficient of the seed-nylon and seedQ235 iron both were 0.055.The three-dimensional six-ball model of the seed was established.The seed stack angle was determined to be 25.25° using Matlab image processing technology.(2)Optimizing the seed-metering device structure parameters.The 3D model of the seed-metering device was made by Solidworks.Based on the measured and calibrated parameters,the EDEM software was used to simulate the structural parameters of the seed-metering device.The data analysis of the test results showed that the uniformity of the spiral groove seed roller was better than that of the straight groove seed roller and the staggered groove seed roller.The uniformity of the spiral groove and the 45° spiral angle seed roller was optimal.The paper Introduced the role of the seed box and the brush and determined the three-dimensional size of the seed box.According to the test seeding effect,the bending angle of the seeding baffle is determined to be 45°,and the number is 4.(3)Determining optimal operating parameters.Based on the theoretical knowledge of motor frequency,speed,belt speed and sowing volume,the paper established the theoretical mathematical fitting equations of belt speed,speed and frequency by y=0.0306x-0.0244,y=1.626x-0.3689 and measured the per rotation displacement for different rotating speeds.The comprehensive seeding test with different speed and speed combinations was designed.The data showed that the uniformity of the seeding was optimal when the belt speed was 0.58 m/s and the speed was 60 r/min.