| The residual mulching film in the field is mixed and bonded with the soil,which increases the difficulty of the residual film recovery.Mulch residue in the field will cause pollution to the environment In,in order to recover the residual film.there are a variety of residual film recovery machines designed by domestic designers or overseas designers.Among them,the commonly used residual film picking up mechanism has elastic teeth type,telescopic rod teeth type,rake teeth type and wheel teeth type,but there are picking up in the process,containing high impurity rate,membrane soil separation difficulties.In order to improve the separation efficiency of membrane soil and lay a foundation for the recovery and reuse of residual membrane,in this paper,a new belt type membrane soil separation device is designed.the following is the main research work:（1）Through literature review and field research and by using the mechanical design,data analysis,finite element simulation and other relevant knowledge,a belt type membrane soil separation device has been designed.it is mainly composed of membrane lifting shovel,membrane soil transmission unit and membrane soil separation unit,etc.The film lifting shovel shovels the film and soil mixture,and the film and soil mixture is transported back and up through the film and soil transmission unit.The soil is crushed by the soil crushing unit,and the soil and residual film are separated by the film and soil separation unit.（2）We measure the physical properties of the mulch for separating the residual film from the soil,The average breaking force and elongation of the new mulching film with thickness of 0.008mm are 1.64N and196.95%respectively.The average breaking force and average elongation of the mulching film with a thickness of 0.008mm and a mulching time of three months are 1.12N and 111.77%.The average breaking force and average elongation of 0.01mm mulching film for three months are 1.44N and 54.59%respectively.Combined with the test data,Theoretical analysis is made on the belt membrane and soil separation device,so as to prepare for the design of the membrane soil separation component and the bench test.（3）The main parts and components of the belt type membrane soil separation device are simulated and analyzed to determine the structure and key dimensions of the main parts and components of the belt type membrane soil separation device.Using ANSYS software to carry out mechanical simulation analysis on the lifting shovel.it is concluded that the maximum deformation produced by membrane shovel is 0.91mm,the maximum strain is 2.50×10-4 and maximum stress is 49.24Mpa,carry out mechanical simulation analysis on the hanging block.Apply the ultimate pressure to the hanging film block,it is concluded that the maximum deformation of hanging film block is 1.57mm,the maximum strain is 5.24×10-4 and maximum stress is 97.22Mpa.The soil removal rate and film retention rate are set as evaluation indexes,and the response surface test is carried out on the membrane soil separation parts.The parameters are rounded according to the optimized value for the test,and when the spacing of the film nails is 90 mm,the cone Angle is 35°,and the speed ratio is 0.80,the value of soil removal rate is 96.55%.The parameters are rounded according to the optimized value for the test,it is concluded that when the length of the film nail is150mm,the transverse spacing is 75mm and the longitudinal spacing is 56mm,the value of the film retention rate is 96.67%.（4）A bench test is carried out on the belt type membrane soil separation device for improving the performance of the device.Taking the residual membrane recovery as the evaluation index,the response surface test has been carried out on the belt membrane soil separation device.The experimental results show that the order of the factors affecting the residual film recovery is as follows:the first speed ratio（the ratio of the speed of the first conveyor belt to the speed of the second conveyor belt）,the first speed ratio and the second speed ratio（the ratio of the speed of the second conveyor belt to the speed of the third conveyor belt）.when the velocity of the first conveyor belt is 0.83m/s,the first speed ratio is 1.18,and the second speed ratio is 0.81,the residual film recovery rate is 95.56%. |
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