Research On The Chaotic Vibrating Screen Of Moist Raw Coal Particles Based On Two Degrees Of Freedom

Vibrating screen is a kind of screening equipment to remove impurities and classify particles with different shapes and sizes by vibrating screen surface,which is widely used in various industrial fields.Aiming at the screening problem of wet granular materials,the existing vibrating screen generally has some problems,such as low screening efficiency,poor screening effect,lacking of enough power for particle flow and so on.In order to solve the above problems,this paper designs a new type of two degree of freedom chaotic vibration screen,and applies the chaotic vibration mechanism to the design of wet raw coal particle screening equipment,which provides a new idea to solve the problems of slow flow of wet particles and material blocking the screen hole,and has important practical significance and research value for the establishment of chaotic vibration screening theory.The main research work of this paper is as follows:1.Based on the chaotic vibration generation mechanism and mechanical design criteria,a new type of two-degree-of-freedom chaotic vibrating screen motion mechanism is proposed and the main structure design is completed.A new type of vibrating screen that can complete complex spatial motion on the screen surface is realized,and with the help of three-dimensional modeling.The software has established a three-dimensional structure model of the chaotic vibrating screen.2.The displacement,velocity and acceleration of the screen surface of the mechanism are modeled and analyzed by analytical method,and the rationality of the mechanism is verified by motion simulation experiment based on virtual prototype technology.The motion trajectory and motion characteristics of the screening mechanism are obtained,which lays a theoretical foundation for the design and research of chaotic vibrating screen.3.In order to study the movement theory and law of materials in the screening process,according to the dynamic and static analysis method,the stress analysis of single particle materials on the screen surface is carried out,and the limit condition of single particle materials moving on the screen surface under the limit stress condition is obtained.Then,based on EDEM and Recurdyn software,the screening process of wet raw coal particles on the screen surface of two degree of freedom chaotic vibrating screen is co simulated and analyzed,and the screening behavior and motion law of wet material particles on the chaotic vibrating screen are obtained,which provides a theoretical basis for the follow-up research.4.Taking the screening efficiency as the evaluation index of the screening performance of the vibrating screen,the orthogonal experimental design is carried out for the simulation calculation scheme of the virtual prototype model,and the influence degree of different parameters on the screening performance is analyzed.Then,using the orthogonal experimental results as the sample data,an appropriate BP-GA neural network model is built to realize the prediction of the screening performance and the optimization of the process parameters,so as to find the optimal screening performance The screening efficiency of the screen achieves the optimal parameter combination,which provides a reference for the structural design and parameter selection of the vibrating screen prototype.