基于可控运动激励与耦合颤振的球磨机破碎能转化强化研究

Aim to solve the big challenge in the powder making via ball grinding, such as low efficient, large power consumption and dim physical crumble mechanism as gain distribute, a new approach is proposed that based on the theory of gain's flow statue and controllable promotion of the medium multi-motion to increase the energy exchange from the grinding medium to material. The innovation of this proposal is described briefly that a high activity zone of cooperation between medium and gains can be found. There effect of the random motion of powder's gain and friction between pellets and medium to the wall of mill is benefit to adjust their distribution and force slipping along cascading layer and then enhance the affection of self-grinding of pellets. On the way, the energy of pellets is increased and the effect of transform the energy from medium and pellets into crumble energy improved yet. This project focus on studying the mechanism, force field and control method of medium-grain layer and its operation system under the mill multi-motion according to the principle of fracture mechanics, coupling relation of movement and vibration and advancing a new evaluation method via lab experiment and DEM date simulation. While we got the key of crush energy conversion between grain layers in high activity pellets zone, the objectives mentioned above can be achieved through the inspection state of the medium-pellets movement and the control method of multi-motion and cooperation with coupling vibration to the ball mill. Finally a reliable experimental ball mill would be designed which can inspect the grinding status via image processing and medium motion with special inspection balls which equally matched with medium and include gyro , acceleration pick-up sensor.

针对球磨机粉体制备中效率低、能耗大，不同运动驱动下颗粒粒度分布及其粉碎机理不清等科学问题，提出基于颗粒流态理论的可控运动激励与耦合颤振新方法以强化磨机破碎能转化。其原理与创新是：通过多运动激励耦合颤振控制，构造出磨介与粉体颗粒的高能粉碎场。利用粉体颗粒的随机性运动和壁面摩擦效应调节磨介-颗粒分布和梯度力场状况，增强颗粒层的摩擦剪切自研磨效应。根据粒度分布状况调整运动激励和耦合方式（含参数），提高冲击碰撞与自研磨作用频度与力度，促进磨介与颗粒群的粉碎场个体能量，强化颤振冲击能量和颗粒层自研磨能量转化为破碎能。项目将应用断裂力学、运动耦合与振动理论，通过图像处理与等效检测球等手段，结合试验与仿真方法，研究可控运动激励下的磨介-颗粒层流作用力场；研究具有理想粉碎效果的颗粒层能量转化特征与区域分布特征，获得优化粉碎效果下的磨介-颗粒的运动控制方法，完成实时监测颗粒流态粒度分布与运动状态的试验磨机.

为了解决球磨机制备过程中的能量有效转化难题，提出一种球磨机运动耦合激励的球磨机粉体制备新方法。研究与分析了不同作用力场下粉体颗粒破碎模型与统计模型，通过设计并实现球磨机多运动耦合激励，提升球磨机回转破碎过程中磨介-筒体内作用于粉体颗粒的有效冲击与剪切破碎的发生概率，达到低能耗下实现粉体破碎的高品质颗粒形状与颗粒粒度。主要研究有：. 研究了球磨机微观破碎冲击力场作用模型，分析了磨介作用于粉体颗粒的破碎层及其范围；采用离散元仿真分析介质冲击能量特征，构建了基于料层单次冲击破碎质量的选择函数和破碎函数；基于粉磨总体平衡模型，揭示了特定粉体材料的最佳介质碰撞能量范围及破碎率，为磨介运动控制提供了理论基础。研究分析了多运动激励下颤振球磨机离散介质群动力学模型，发现了离散介质群的流型以及其运动的数学关系，讨论了碰撞能与球磨机内颗粒破碎率的数学关系。通过仿真与对比实验，研究了衬板边数对碰撞能级分布和磨矿效果的影响，强化颤振冲击能量和颗粒层自研磨能量转化为破碎能，提出了具有良好研磨效果的角螺旋衬板及其相关运动控制参数。研究并设计了新型球磨机试验平台，采用PID控制器实现磨机多运动激励，以粉体颗粒粒度为监测与控制目标，基于颗粒层能量转化特征与区域分布特征理论研究成果，整定了PID的控制参数，获得球磨机运动耦合控制的规则。利用微惯性测量技术研究并设计了与介质球形状与质量相当，内含三轴加速度计、陀螺仪、磁强计等测量单元的检测球，突破了定量追踪磨介运动状态数据的技术瓶颈；利用数字图像处理技术对球磨机内部粉体粒度进行实时检测与分析，获得平均粒径与颗粒分布；建立了合适的健康指数并用于判断轴承健康状态的异常阈值，截取出轴承从早期故障发生到失效这一性能退化阶段的数据用于剩余寿命的预测分析，解决了多运动颤振激励对球磨机轴承寿命及其故障防范等问题。最终实现了多运动激励耦合颤振的高效球磨粉体制备方法。