Authors

Abstract

During the vibration crushing of wheat bran, an impact-blocking effect occurred between the grinding media and wheat bran powder. Experimental results showed that the impact depth exhibited quadratic relationship with respect to particle size, while the acceleration and damping coefficients followed the order: fine powder > coarse powder > uncrushed bran > micro powder. Increasing the diameter of the grinding media enhanced the impact depth by 81.10% for uncrushed bran and by 40.41% for coarse powder, but reduced acceleration by 45.35% and 29.56%, respectively. Damping coefficients positively correlated with grinding media diameter but negatively with cylinder diameter. Material layer thickness demonstrated threshold-dependent bidirectional regulation, peaking at 40 mm, with maximum damping difference rates of 20.40% for uncrushed bran and 17.67% for coarse powder. Drop height linearly influenced the impact depth, while showing cubic relationships with both acceleration and damping. Both parameters were minimized at 500 mm. Sensitivity analysis identified grinding media diameter as the primary factor affecting damping coefficients, revealing the sensitivity hierarchy: grinding media diameter > drop height > material layer thickness > cylinder diameter. This study provided a theoretical foundation and experimental support for optimizing the vibration superfine crushing efficiency of wheat bran.

Abstract in Chinese

在振动粉碎过程中，磨介与小麦麸皮粉体之间存在冲击阻滞效应。实验结果表明，冲击深度在振动粉碎小麦麸皮时，磨介与粉体间存在冲击阻滞效应。实验表明，冲击深度与粉体粒度呈二次非线性关系，加速度、阻尼系数大小顺序为：细粉＞粗粉＞未粉碎麸皮＞微粉。增加磨介直径可使未粉碎麸皮和粗粉的冲击深度分别增加81.10% 和40.41%，加速度降低45.35% 和29.56%。阻尼系数与磨介直径正相关，与圆筒直径负相关。料层厚度对各参数有双向调控作用，临界厚度为40mm。下落高度与冲击深度线性相关，与加速度、阻尼呈三次非线性关系，500mm时二者取极小值。灵敏度分析显示，磨介直径是影响阻尼系数的主因，灵敏度顺序为：磨介直径＞落差高度＞料层厚度＞筒体直径。该研究为优化小麦麸皮振动超微粉碎效能提供依据。