Design And Experimental Study On Grain Crushing Device Of Yellow Storage Corn Based On Differential Roller

As a grain,economic and forage crop in China,the output of Maize in China in 2020 was 260.67 million tons.In order to ensure the healthy and stable development of China’s animal husbandry,the state launched the supply side reform of "changing grain to feed" and the guiding opinions on accelerating the mechanized development of animal husbandry,which provided policy guidance for solving the shortage of roughage in the rapid development of animal husbandry.In this context,how to convert corn into roughage has become a research hots pot.At present,cattle and sheep in China are mainly fed with refined feed in the feeding process,while the existing corn yellow storage mainly uses corn straw as raw material for fermentation,which belongs to the category of coarse feed feeding.The corn grain contains high crude protein,fat,sugar and other substances.The corn ear is chopped and the corn grain is broken for yellow storage.Compared with a single straw yellow storage,it can meet the needs of ruminants for refined feed,At the same time,it can also improve the intake of protein and fat.However,in the feeding process,we found that if the corn grain is not completely broken,its nutrients are difficult to absorb,and then directly excrete or form rumen.Therefore,it is the key to solve the above problems to carry out the research on the crushing technology of yellow stored corn grains.This thesis focuses on the research of differential roller yellow storage corn grain crushing device,and aims to improve the grain crushing rate.Combined with the current research status of corn grain crushing technology,a corn grain crushing method based on the combination of extrusion and rubbing based on differential action is proposed,and a serration differential roller corn grain crushing test-bed is designed.The roll shape structure of serration differential roller is determined through theoretical analysis and discrete element simulation test,Through finite element modal analysis and random vibration test,the natural frequency of differential roller and the vibration characteristics and vibration mechanism of serration differential roller corn grain crushing test-bed at different speeds are explored,and its vibration time-domain statistical characteristics and frequency distribution law are obtained,Combined with discrete element virtual simulation test and bench test,the crushing effect of serration differential roller corn grain crushing device is explored,in order to provide data reference and theoretical basis for improving the crushing effect of yellow stored corn grain and improving the transformation and absorption of nutrients in yellow stored feed.The main research contents of this thesis are as follows:(1)The moisture content and mechanical properties of corn grains were tested.The test sample of corn grain in yellow storage period is obtained,and the compression and shear tests in length direction,width direction and thickness direction are carried out on the sample to obtain the mechanical properties of corn grain,so as to provide relevant basic parameters for constructing the discrete element model of corn grain.(2)A serration differential roller corn grain crushing test-bed was developed.The test-bed is mainly composed of feeding device,chopping device and grain crushing device.The crushing mechanism and structural parameters of the core grain crushing device studied in this thesis are designed.It is determined that the diameter of serrated differential roller crushing roller is 250 mm,the front angle of crushing roller is 10 °,the blunt angle is55 °,the width of tooth top is 2mm Serrated differential roller corn grain crushing test-bed with grinding tooth height of 8mm and arrangement of front angle to front angle grinding teeth.(3)Based on the discrete element method,the grain crushing device of serrated differential roller is simulated,analyzed and tested by discrete element simulation software.The discrete element bonding model of corn grain is constructed,and its related bonding parameters are determined.The degree of corn grain fragmentation is indirectly analyzed from the fracture number of bonding bond in the discrete element bonding model of corn grain.The grain crushing device of the designed serration differential roller corn grain crushing test-bed is simulated,analyzed and tested,the influence law of key parameters on the operation effect is explored,and the best combination of working parameters is determined: the speed of crushing roller is 4588 r / min,the speed of lower crushing roller is 3823 r / min,and the gap between crushing rollers is 3mm,The broken rate of bond bond in the discrete element bonding model of yellow stored corn grain reached 95.16%.Based on the serration differential corn grain crushing test-bed,the verification test was carried out under the condition of the simulation results.The results showed that the average grain crushing rate of yellow storage corn was 91.1%;16.3% of the Yellow stored corn grains were completely broken;64.4% of the Yellow stored corn grains were in standard broken state;The grains of 12.1% yellow stored maize were basically broken;7.2% of the Yellow stored corn grains were not broken,and the relative error between simulation test and bench test was 4.06%.(4)Through random vibration test,the vibration characteristics and vibration mechanism of serration differential roller corn grain crushing test-bed under different speeds and working conditions are explored.The time-domain statistical characteristics and frequency-domain distribution law of its vibration are obtained,which provides a reference for improving its working reliability.