Property Function to Compute the Dustiness of Powders

分散固体的粉尘性可以理解为一种性质，当在气体环境中处理时，其行为类似于气溶胶，释放出给定数量和大小分布的相应颗粒分数。一般来说，这种粉尘的释放是不可取的，因为它可能导致材料损失，并且通常与相关人员的暴露有关，或者代表环境污染的风险。因此，粉尘是一种产品属性，它可能沿着工艺路径发生变化，例如通过所涉及的固体的粉碎、团聚、分类或混合。作为该项目的一部分，将确定描述在动态过程中集成的时变粉尘的属性函数，该函数是粒度分布、颗粒形状和特定处理过程中颗粒相互作用的函数。为此目的，将在非常明确的边界条件下使用实验室设备进行实验，例如在静止空气中自由落体，在旋转鼓中移动，分散，压力波动方法或气流分散，并建立基于物理的模型。通过引入所谓的分馏释放等级，这些模型将得到改进。结合对相关应变函数（设备性能）和刚度函数（材料性能）随时间变化的描述，该方法将有助于更好地预测粉尘的瞬态过程。将与项目伙伴合作，评估已发现的属性功能在实际应用中的适用性。

The dustiness of a disperse solid can be understood as a property, which when handled in a gaseous environment, behaves similar to an aerosol, releasing the respective particle fraction of given quantity and size distribution. In general, this release of dust is undesirable because it might result in material loss and often is associated with an exposure of personnel involved or represents a risk of environmental pollution.The dustiness is therefore a product property, which might change along the process path, for example through comminution, agglomeration, classification or mixing of solids involved. Property functions which describe time variable dustiness integrated in dynamic processes as a function of the distribution of particle size, particle shape, and particle interaction during a certain handling, are to be determined as part of this project.For this purpose, experiments with laboratory equipment such as free fall in still air, moving in a rotating drum, dispersion, pressure surges method or airflow dispersion will be performed at very well defined boundary conditions and physically based models will be established. These models will be improved through the introduction of the so called Fractionated grade of release. Together with the description of time-dependent changes of the related strain-functions (apparatus properties) and rigidity-functions (material properties) this approach will help to better predict transient processes of dustiness. The discovered property functions will be evaluated for their suitability in practice in cooperation with project partners with respect to application.