基于CFD-DEM耦合的卷烟机流化床气流参数与烟丝梗签适配数学模型研究OA

[Background]Airflow parameters in cigarette production are commonly adjusted based on operator experience when the specifications,structures,or mixing ratios of cut tobacco and stems change,resulting in low adjustment efficiency and unstable cigarette quality.[Methods]The physical parameters of cut tobacco and stems from three representative product specifications were measured experimentally.A CFD-DEM-coupled gas-solid simulation model of the fluidized-bed tobacco-feeding system and suction chamber was established.Orthogonal experiments were conducted to determine the relationships between the cut tobacco-stem mixing ratio,physical structure,and pressures in four throttle-valve-controlled regions.Multiple nonlinear regression was combined with genetic algorithm optimization to derive the mathematical model.Model accuracy was evaluated through simulations and machine trials.[Results]The test data showed that(1)the model quantitatively predicted the four throttle-valve pressures using four inputs:the cut tobacco-stem mixing ratio,cut tobacco density,stem equivalent diameter,and cut tobacco equivalent diameter.All models had goodness-of-fit values greater than 0.95 and mean absolute errors below 3%.(2)In machine trials,after the parameters were adjusted according to model predictions,the cut tobacco content in the separated stems remained at 1.8%～2.5%,tobacco loss from the cigarette ends was≤8.5 mg/cigarette,and the standard deviation of cigarette weight was≤20 mg.Adjustment efficiency increased by 80%compared with experience-based adjustment.(3)The mixing ratio was the dominant factor affecting the primary separation pressure and the negative pressure above the fluidized bed.Cut tobacco density had the greatest effect on distribution-box pressure,whereas stem size significantly affected the negative pressure in the suction chamber.[Conclusion]The model accurately matches the mixing characteristics of cut tobacco and stems to the airflow parameters of the tobacco-feeding and rod-forming machine.It can rapidly guide pressure adjustments in the fluidized bed and suction chamber,reduce commissioning time during product changeovers,and improve cigarette-quality stability.