Research On Bionic Design For Key Components Of Hammer Mill

Hammer mill is widely used in feed processing industry because of its strong applicability to raw materials,single structure and convenient operation.During its operation,the material is thrown into the inner wall of the sieve after being broken by the hammer.Limited by the annular structure sieve,the crushed material is easy to produce a “material-air circulation layer”on the inner wall of the sieve.Many factors,such as the impact of hammer on the crushing effect of materials and the circulation layer produced by the restriction of the annular structure of the sieve,jointly cause the serious over-grinding of the crusher and the low discharge rate,which leads to the problems of low crushing efficiency and high crushing energy consumption.Therefore,based on the similarity of “ function + structure ”,this paper learns from nature and explores the design method of bionic hammer and bionic sieve based on the characteristics of beaver door tooth and pigeon feather wing.In order to improve crushing efficiency and reduce energy consumption.The main contents of this paper are as follows :1.Reverse reconstruction of Bionic model.Based on the similarity analysis of “function+ structure”,the beaver incisor and pigeon wing were selected as biological models.The point cloud data of the beaver skull was obtained by industrial CT scanning equipment and the point cloud data of the pigeon wing was obtained by handheld three-dimensional scanning equipment.Then the point cloud data was preprocessed by reverse engineering software Geomagic Studio,and the three-dimensional model of the beaver skull and the pigeon wing was reconstructed.The modeling error was calculated,which laid the foundation for the follow-up bionic design.2.A new bionic hammer design method based on the structural characteristics of beaver door teeth is proposed.Through the determination,extraction and characterization of the characteristic structure of the beaver door tooth,the bionic coupling unit of the model is used for the design of the hammer tooth surface.Based on the simulation calculation of the“hammer-material ” fracture,the fracture time and fracture stress of the material are used as the bionic efficiency evaluation indexes.The parameter optimization method of the Bionic Hammer based on the response surface proxy model is constructed to seek the best Bionic parameter set.3.A new design method of bionic sieve based on the geometric characteristics of pigeon wings is proposed.The characteristic structure of pigeon feather wing was determined,extracted and characterized.The model bionic coupling unit is used for the structure design of the screen.Based on the simulation calculation of the flow field in the crushing chamber with the bionic screen,the pressure difference of the crushing chamber is used as the Bionic Efficiency Evaluation Index.The optimization method of the bionic sieve parameters based on the response surface proxy model is constructed to seek the best bionic parameters.4.The experimental platform of the crusher was built.The working performance of the designed bionic hammer and ordinary hammer,bionic sieve and ordinary sieve were compared and analyzed to verify the effectiveness of the bionic design method.