Research And Experiment Investigation Of Tumbler Screen Type Residual Film–impurities Wind Separator Screen Hole-Clearing Device

The tumbler screen type residual film–impurities wind separator is the key equipment of the waste film resource utilization debris removal process.In this paper,the theoretical analysis and structural design of the screen hole-clearing device are based on the study of the material characteristics of the residual film-impurity mixture.In this paper,theoretical analysis and structural design of the sieve hole-clearing device are carried out based on the study of the material characteristics of the film-hybrid mixture.Using a combination of computer simulation and experimental verification,the structure and operating parameters of the screen hole-clearing device are optimized,and the key device operation form is determined.It provides theoretical support and technical reference for the design of various types of screen hole-clearing devices.The following work has been carried out in this paper.(1)Determination of the material properties of each component of the residual film-impurity mixture.The recovered and crushed residual film-impurity mixture was sorted and weighed,and the mass ratio of each component was determined as follows: 36.8% of the residual film,18.4% of straw,and 44.8% of soil.The basic physical properties,contact parameters between the components,and the suspension rate of the residual film-impurity mixture were determined.It can provide data support for the subsequent simulation.(2)Research on the design of a screen hole-clearing device.The screen hole-clearing device is designed for the problem of screen hole clogging during the working process of tumbler screen type residual film–impurities wind separator.It is explained that the screen hole blockage is essentially the balance of force of the residual film-impurity mixture at the screen hole.The three-dimensional model of the screen hole-clearing device was constructed based on the design of external means to disrupt the force equilibrium at the screen hole.The key structure was analyzed by finite element analysis software,and the structural strength of the whole device was determined to meet the requirements,and the prototype was manufactured on this basis.(3)Simulation study of screen hole-clearing and plugging device.Based on the working principle of the screen hole-clearing device,a mathematical model was constructed for theoretical analysis.It is determined that when the jet air velocity of the nozzle is greater than1.151 m/s,the jet air can break the force balance of the blockage at the screen hole.Through the simulation of the internal flow field of the screen hole-clearing device,when the centrifugal blower is installed diagonally and the pressure stabilization tube is added,and the fan wind speed is greater than 9.2 m/s,the nozzle jet airflow speed meets the requirements of clearing the plug.Test verification,the working conditions,and the screen hole-clearing device nozzle jet air velocity average value of 3.81 m/s,the minimum value of air velocity of1.22 m/s,all meet the requirements of clearing the plug.Only 8.28% of the screen holes were blocked,and the ratio of impurities in the residual film was 7.33%.The blockage ratio of screen holes and the ratio of impurities in the residual film are 16.27 and 4.64 percentage points lower respectively than before the installation of the screen hole-clearing device.(4)Optimization study of the structure and working parameters of the screen hole-clearing device.For the use of a screen hole-clearing device in the process of continuously increasing the fan wind speed,there are still some nozzle jet air velocity are small.Using the three-factor,three-level center combination test method,with the distance from the nozzle to the screen surface,fan wind speed,the number of airflow pipes as the test factors,the ratio of impurities in the residual film,the blockage ratio of screen holes as the evaluation index,the screen hole cleaning device structure,work parameters optimization test.When the distance from the nozzle to the screen surface is 102 mm,the fan wind speed is 24m/s and the number of air pipes is 4,the ratio of impurities in the residual film is 5.86% and the blockage ratio of screen holes is 5.41%.Compared with the rate before optimization,the rate of impurities in the residual film and the blockage ratio of screen holes was reduced by2.42 and 1.92 percentage points respectively.The rate of impurities in the residual film and the blockage ratio of screen holes was reduced by 7.06 and 18.19 percentage points,respectively,compared with the rate before the installation of the screen pore cleaning device.The rate of impurities in the residual film and the blockage ratio of screen holes remained unchanged during the continuous operation of the device,indicating that the optimized device has significantly improved the clearing effect and stable performance.