Numerical Simulation Study And Structural Design Of Gas-Solid Two-Phase Flow In A Secondary Separation Device

In 2013,the Tobacco Monopoly Bureau issued the “Opinions of the National Tobacco Monopoly Administration on Promoting Lean Management of Enterprises”,which puts forward the requirements of “lean management,control and efficiency enhancement”.However,in the production of cigarettes,in order to ensure the quality of the coiling process reaches the level of process requirements,the original volume The mixture of the stems separated from the unit usually contains more than 20% of the finished shredded tobacco.This part of the shredded tobacco is directly sent to the decontamination room by the de-stalking system,thereby causing waste of tobacco.In order to solve the problem of high silk content in the stalk,domestic and foreign scholars have carried out a lot of research.Although the silk content of the stalk of the coiling unit is reduced to some extent,there are still some defects and deficiencies,such as improved crimping.The overall performance of the unit has certain impact,high transformation cost,inconvenient installation and maintenance,large installation size affecting the installation layout,excessive tobacco cutting rate due to excessive wind selection path,and loss of tobacco moisture.In view of the shortcomings of the above research,this paper comprehensively uses vacuum separation technology,centrifugal separation technology and other separation methods to design an external type of stem secondary separation device,which has simple structure,convenient maintenance and maintenance,and no additional power source.Does not change the appearance of the original coiling unit.The specific research contents of this paper are as follows:(1)Analyze the working mechanism of the original ZJ17 coiling unit to separate the shredded tobacco,find out the cause of the high silk content in the stem,and propose an improved scheme.Three-dimensional modeling of important components of the stemsplitting secondary separation device was carried out by Solidworks software,including vacuum suspension chamber,centrifugal separation chamber,and trap collector.(2)Using ANSYS Workbench to simulate the airflow in the cavity of the suspension cavity without adding tobacco particles,and analyze the position of the elastic mechanism,the loose elastic mechanism,the number of the wind block,and the lower end of the rectangular cavity.The effect of changes in the width and the height of the upper end to the height of the rectangular cavity on the airflow in the vacuum suspension chamber.(3)By studying the gas-solid two-phase flow theory and combining the actual situation of the project.Using FLUENT software to analyze continuous gas flow,EDEM software analyzes discrete particle flow,taking full account of the collision between tobacco,stem and wall,and using CFD-EDEM coupling method to consider the relationship between discrete particle phase and continuous gas phase flow.interaction.The orthogonal test of 3 factors and 3 levels was designed to analyze the primary and secondary factors affecting the separation of tobacco in the suspension cavity,and a set of optimal data was obtained to optimize the structure of the suspended cavity.(4)Simulate the movement of tobacco particles in the suspension cavity under the optimal structure,analyze the movement state of the tobacco stem sign,and calculate the silk content in the stem.The test sample was installed to test the efficiency of separating the shredded tobacco from the secondary separation device of the stem,and the simulation results and test results were compared to determine whether the winding quality of the crimping machine was affected after the installation of the secondary sequestration device.After installing the secondary separation device of the stem design designed in this paper,the average stalk of the ZJ17 coiling unit was reduced to 1.80%,and the silk content of the average stem was 2.79%.The average deviation between the simulation result and the experimental result was 23.03%.The results show that:(1)the simulation results are basically consistent with the experimental results;(2)The effect of separating the tobacco from the secondary separation device designed in this paper is significant.