Numerical Simulation And Experimental Study Of Gas-solid Two-phase Flow In Tobacco Stem Two-stage Separation Device

In cigarettes,the amount of stem stick content will directly affect the appearance and quality of cigarettes and the smoking effect.For this reason,in the process of forming cigarette rolls,the cigarette making machine adopts a multi-stage wind stalk removal method to reduce the content of stalks in the shredded tobacco.At the same time,part of the finished tobacco is also removed during the process of removing stalks.The content of finished tobacco in the finished product accounts for about20%.Especially in the process of high-end cigarette rolling,the content of finished shredded tobacco in the stalk rejection is higher,which leads to an increase in the consumption of shredded tobacco in a single box of cigarettes.In order to effectively reduce the consumption of shredded tobacco,it is of great significance to develop a stand-alone in-situ separation device with low energy consumption,high recovery rate,and low stem content in the recovered shredded tobacco.Aiming at the above problems,this paper designs a new type of stem-stick secondary separation device,which is to remove the stem-stick from the cigarette maker to separate the stem-stick and the tobacco on-line.The separated tobacco is sent to the tobacco silo of the cigarette maker for use,and the stem-stick material enters.Centralized processing of the suction system.(1)The two-stage separation device used suspension separation and inertia separation to separate the cut tobacco from the stalk and stalk to achieve the purpose of recovering the cut tobacco.(2)Establish a two-stage separation chamber model,use CFD numerical simulation to simulate the separation chamber of the two-stage separation device,and analyze the gas flow field and pressure distribution cloud diagram of the two-stage separation chamber under different air supply speeds.(3)The gas-solid two-phase flow theory is studied,and the particle trajectory model is selected to numerically simulate the stem-stick secondary separation device,and the movement trajectory of tobacco particles and stem-stick particles in the variable cross-section annular channel and the collection efficiency of tobacco particles and stem-stick particles are obtained.(4)The prototype of the stem-stick secondary separation device was made,and the experimental research was carried out.The experimental data was collected and analyzed.It was concluded that the average relative error between the experimental data and the numerical simulation value of the collection efficiency of tobacco and stem-stick was very small,which verified the accuracy of the numerical simulation calculation results.Through the experimental research on the separation of the stalk rejections,it is obtained that the stalks secondary separation device achieves the purpose of efficiently recovering the tobacco shreds from the stalks when the primary air supply speed is 12m/s and the secondary air supply speed is 5m/s.Reduce the rate of silk in the stem.