禽蛋壳膜回收分选装置参数优化

目的：有效利用废弃蛋壳和蛋壳膜。方法：对废弃蛋壳进行分离和分选，利用Fluent和EDEM耦合仿真研究了分选筒上、下出口直径等结构参数对流场特性、颗粒轨迹的影响，分析了流场特性和壳膜的捕捉率，优化了分选筒的气流出口尺寸。以筒顶角度、吸风机负压、送料口风速和固体负荷率作为试验因素，蛋膜和蛋壳的回收率作为评价指标，进行分选蛋壳膜试验，并进行优化设计。结果：减少分选筒上、下出口直径会增大筒内压降损失和近壁切向速度，当上出口直径为0.4D(D为直筒段直径)、下出口直径为0.5D时，蛋壳和蛋膜的捕捉率最高。筒顶角度为45°，固体负荷率为1 000 g/s，送料口速度为4.64 m/s，吸风机负压为336.61 Pa，此时蛋膜回收率为92.94%，蛋壳回收率为97.90%。结论：上出口负压与进料口风速主要影响分选筒内部流场分布，固体负荷率会使物料之间产生不同的相互作用。在优化后的工艺组合下，该分选设备具有良好的分选效果。

Optimization on parameters of collecting and sorting device for discarded poultry eggshells and eggshell membranes

Objective:To efficiently exploited the discarded eggshells and eggshell membranes. Methods: The discarded eggshells was separated and collected. Used Fluent and EDEM coupling simulation to study the flow field characteristic and particles trajectory, which affected by structure parameters such as upper outlet diameter and lower outlet diameter of the collecting barrel. By analyzing flow field characteristic and capture rate of eggshells as well as eggshell membranes, the size of collecting barrel was optimized. The top angle, the vacuum of suction machine, the feeding inlet air velocity, the solid load of feeding inlet were used as the test factors. The recovery rates of eggshells and eggshell membranes were used as the two evaluation indexes. The experiments of collecting eggshells and eggshell membranes were performed and optimized. Results: The simulation showed that an appropriate decrease of the diameter of the upper and lower outlets will lead to more loss pressure drop in the cylinder, and increase the tangential velocity in the cylinder. When the upper outlet diameter was 0.4D (D is the diameter of the cylinder) and the lower outlet diameter was 0.5D, the capture rate of eggshells and eggshell membranes was the highest. The test results showed when the cyclone top angle was 45°, the solid load rate was 1 000 g/s, the feeding inlet air velocity was 4.64 m/s, the vacuum of suction machine was 336.61 Pa, the eggshell membranes recovery rate was 92.94%, and the eggshells recovery rate was 97.90%. Conclusion: The vacuum of suction machine and the feeding inlet air velocity mainly affect the flow field in the collecting barrel, and the solid load will cause different interactions between materials. After the experiment and simulation analysis of the factors that affect the collecting effects, the optimal level combination of factors is obtained. With the combination of these factors, the recovery rates of eggshell and eggshell membrane are higher, and the collecting device has a good effect.