The Research Of Stratification Mechanism Of Vibration Screen Based On Composite Motion Of Swing And Translation

Vibration screen is the most widely used screening facility in the industry,vibrated by its vibrating motor that causing the materials to flow through the screen and to be separated depending on its size. Practices show that the development and innovation of vibration screen come from the breakthrough of the screening mechanism. The screening process is divided in four details: looseness, stratification,touch, penetration. So, in this paper, the process of screening with the new vibrating mode was studied based on the discrete element method(DEM). The numerical simulation about the process of the new vibrating screen based on composite of swing and translation has been done to analyze the effects of different parameters on stratification and screening efficiency. The main works are as follows:1. We establish a three-dimensional model of vibration screen based on composite of swing and translation and use EDEM software to simulate the process of screening. Experiments are designed to research stratification mechanism.2. Stratification sedimentation coefficient is newly put forward. We use sedimentation difference as the characteristic quantities of the process of stratification under the new type of vibration. Find the relationships between stratification and screening parameters(vibration parameters, structure parameters and production process parameter), and establish the model between sedimentation difference and screening parameters based on stratification sedimentation coefficient.3. Optimization of screening parameters: In order to find the significance of screening parameters effecting stratification, design the orthogonal test of vibration parameters and structure parameters under the consideration of the interaction between vibration frequency and swinging frequency. In the end, obtain combination of the optimal parameters.4. Forecast of sedimentation difference: From the aspect of the relations between screening parameters and sedimentation difference, support vector regression(SVR) based on structural risk minimization is applied, by establishingSVR forecast model to forecast sedimentation difference. By selecting appropriate kernel function and parameters, the proposed approach is used for forecasting sedimentation difference, experimental results show that the above method obtained less error. It is able to express the nonlinear mapping relation between sedimentation difference and screening parameters. Using SVR to predict sedimentation difference is feasible. It will provide a new method to predict sedimentation difference.5. Analyze screening parameters’ influence on screening efficiency by comparing sedimentation difference with screening efficiency under different screening parameters to enrich stratification theory.