Development of a dynamic-physical process model for sieving

开发筛分动态物理过程模型

• 批准号: 238373056
• 负责人: Professor Dr.-Ing. Harald Kruggel-Emden
• 金额: --
• 依托单位: Fachgebiet Mechanische Verfahrenstechnik und Aufbereitung (MVTA)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/238373056?language=en
• 关键词: Development; dynamic; physical; process; model

In mechanical process engineering and materials preparation technology, it is frequently required to separate disperse solid systems according to their particle sizes and shapes. This is necessary within combined processes because bulk materials often consist of particles of different, highly non-spherical form and broad size distribution but, defined narrow particle size distributions are needed for subsequent process steps. On this background, sieving is a technically simple but well-suited, separation process which can be performed discontinuously and continuously. Despite its established nature, the design, optimization and scaling of screening processes is not trivial since the process, plus its subprocesses and its dynamics, is still not satisfactorily understood. Although, good development takes place, there is still a lack of physically based process models.In order to design or optimize screening processes, particle-based simulation methods, such as the Discrete Element Method (DEM), are applied, which allows the modelling of the process step screening in detail after an appropriate validation. Likewise, phenomenological models are suitable for the optimization of apparatus-specific and operational parameters. Therein, simple models, which are used in stationary process simulation packages, only consider the integral outcome of the separation operation. Other models include the interactions between stratification and particle passage through the screen. Usually, the empirically determined, material-, operating-, and apparatus-specific parameters for phenomenological models were determined experimentally, whereas direct derivations of parameters for dynamic models for the process step screening were rarely carried out by DEM applications. Particularly, this applies to investigations of systems with real particles of complex shape under the influence of wetness.While during the first two funding periods of the proposed project, discontinuous and continuous sieving in realistic systems with dry and moist particles was investigated, wet screening will be focussed in the third phase. By means of DEM simulations, which were validated by experimental investigations within the SPP 1679 and will be validated for the new system properties, discontinuous and continuous screening processes are performed time resolved with different mechanical excitation for polydisperse systems of real particle shapes with the effect of wetness under changing operational conditions. Dynamic phenomenological models, which are extended by the observed relationships and predictive properties, are used to represent the numerical results. Simplified DEM simulations are applied to obtain the required parameters for the new, runtime efficient models which can be used in dynamic, combined bulk solids process simulations.

在机械加工工程和材料制备技术中，经常需要根据分散固体体系的粒径和形状对其进行分离。这在组合工艺中是必要的，因为散装材料通常由不同的、高度非球形且尺寸分布广泛的颗粒组成，但是后续工艺步骤需要确定的窄粒度分布。在此背景下，筛分是一种技术简单但非常适合的分离过程，可以间歇和连续进行。尽管其性质已确定，但筛选过程的设计、优化和扩展并非微不足道，因为该过程及其子过程及其动态仍未得到令人满意的理解。尽管取得了良好的发展，但仍然缺乏基于物理的过程模型。为了设计或优化筛选过程，应用了基于粒子的模拟方法，例如离散元法（DEM），它允许在适当的验证后对过程步骤筛选进行详细建模。同样，唯象模型适用于设备特定参数和操作参数的优化。其中，用于固定过程模拟包的简单模型仅考虑分离操作的整体结果。其他模型包括分层和粒子通过屏幕之间的相互作用。通常，现象学模型的经验确定的、材料、操作和设备特定的参数是通过实验确定的，而用于工艺步骤筛选的动态模型的参数的直接推导很少通过 DEM 应用程序进行。特别是，这适用于在湿度影响下对具有复杂形状的真实颗粒的系统进行研究。虽然在拟议项目的前两个资助期间，研究了具有干燥和潮湿颗粒的实际系统中的不连续和连续筛分，但湿筛分将集中在第三阶段。通过 DEM 模拟（已通过 SPP 1679 内的实验研究进行验证，并将验证新的系统特性），通过不同的机械激励对真实颗粒形状的多分散系统进行时间解析的不连续和连续筛选过程，并在变化的操作条件下考虑湿度的影响。动态现象学模型通过观察到的关系和预测特性进行了扩展，用于表示数值结果。应用简化的 DEM 模拟来获取新的、运行时高效的模型所需的参数，该模型可用于动态、组合散装固体过程模拟。