基于DEM仿真与试验验证的双轴螺旋输送机结构优化分析

Structure optimization and analysis of twin-shaft screw conveyor based on DEM simulations and experimental validation

针对螺旋输送机的输送效率问题,对双轴螺旋输送机输送颗粒物料的过程进行离散元法数值计算,并与单轴螺旋输送机输送物料的试验和模拟结果进行对比。在试验验证了仿真模型和参数正确的基础上,对双轴螺旋输送机的轴距和螺距2个参数与质量流速率(■)间的定量关系进行二元二次多项式拟合,得到拟合优度R^2=0.964 6的回归方程。研究结果表明:1)双轴的相对转动方向对■没有影响;2)螺距和轴距对■均有明显影响。■随着轴距的增大显著增大,大螺距时会在达到极值后趋于稳定或略有下降;■随着螺距的增大先增大至峰值后下降;3)双轴的螺距和轴距对颗粒运动影响显著。两轴中间位置颗粒的最小轴向平动速度与轴距呈现近似线性的递减关系,且螺距越大,其减小趋势越明显。

In this study,the process of transporting granular materials by double-shaft screw conveyor was simulated with discrete element method and compared the results of experiments and simulations of single-shaft screw conveyor.Based on the accuracy validation of numerical model and parameters with experiments,the quantitive relationship between shaft distance,screw pitch and mass flow rate (M) was fitted with a binary quadratic polynomial function of the fit goodness of R2=0.964 6.The results showed that:1)Rotating directions of two shafts did not affect the M was evidently influenced by shaft distance and screw pitch M increased with the increasing of shaft distance obviously,and it decreased after reaching the maximum value under the larger pitch M increased with the increasing of pitch and decreased after the maximum value.3)The behavior of the particles was influenced by the shaft distance and screw pitch.Tnd the minimum velocities of particles at the central position of the double-shaft decreased linearly as the shaft distance increased,and the decrease tendency was more obvious with larger screw pitch.