Dynamics of spray granulation in continuously operated horizontal fluidised beds

本研究项目旨在详细研究连续操作的多级流化床造粒过程中产生的复杂过程动力学。由于存在不同的处理室、在每个处理室中存在具有不同功能的区域、在设计不同室和具有不同分类特性的区域之间的内部耦合时的高度灵活性、由于干燥而导致的颗粒和流体相之间的耦合、外部坐标的位置变化和分类特征，以及表征产品特性的多个内部坐标。因此，该项目遵循多尺度方法，将实验工作与不同的建模方法和过程动力学的非线性分析相结合。此外，该小组应用离散颗粒模型（discrete particle modeling，简称DPM）来描述不同腔室之间以及腔室内不同功能区之间的颗粒传输动力学，并特别强调分类特性。另一个重点是对具有外部产品分类和再循环的过程的外围进行建模。Tsotsas小组开发了用于描述不同过程配置和不同操作条件下颗粒特性随时间演变的总体平衡和传热传质模型，包括模型的参数化。此外，该小组还提供了颗粒特性的详细表征（粒度分布、X射线显微层析成像、扫描电子显微镜、机械稳定性）Kienle小组致力于发展系统和参数识别的新方法，以及连续介质非线性动力学行为的系统理论分析。多室流化床造粒分析提供了对基本过程的进一步了解。在与其他小组的合作，结果将用于评价，完善和发展人口平衡建模方法的歧视。自动调整控制器将被开发，以加快耗时的实验。这些将与预测和检测可能的开环不稳定性的适当方法相结合，并在工厂实施。

This research project aims at a detailed investigation of the complex process dynamics arising in continuously operated multi-stage fluidized bed granulation. This process has prototypic character for the dynamic simulation of coupled particle processes, due to the presence of different process chambers, the presence of zones with different functionality in each process chamber, the high flexibility in designing the internal coupling between different chambers and zones with different classification characteristics, the coupling between particle and fluid phase due to drying, varying positions and classification characteristics of external recycles, and multiple internal coordinates to characterize product properties. Consequently, the project follows a multi scale approach, which combines experimental work with different modeling methods and a nonlinear analysis of process dynamics.Experiments for the multi-chamber fluidized bed granulator will be done by the Heinrich group. Further, this group applies discrete particle modeling (DPM) to describe the dynamics of particle transport between different chambers and different functional zones within the chambers, with special emphasis on classification characteristics. Another focus is on the modeling of the periphery for processes with external product classification and recycle.The Tsotsas group develops population balance and heat and mass transfer models for the description of the temporal evolution of particle properties for different process configurations and different operating conditions, including parameterization of the models. Moreover, this group provides detailed characterization of particle properties (particle size distribution, X-ray micro tomography, scanning electron microscopy, mechanical stability) as well as novel particle tracking velocimetry experiments for investigation of particle transport at weirs.The Kienle group is concerned with the development of new methods for system and parameter identification and system theoretical analysis of the nonlinear dynamic behavior of continuous multi-chamber fluidized bed granulation. The analysis provides further insight into the underlying processes. In cooperation with the other groups, results will be used for an evaluation, refinement and discrimination of the developed population balance modeling approaches. Auto tuning controllers will be developed to speed up the time consuming experiments. These will be combined with suitable methods for prediction and detection of possible open loop instabilities and implemented at the plant.