GOALI: A Multiscale Modeling Framework for Predicting Granule Property Evolution in Mixer Granulators

该项目的目标是开发以基础为基础的多尺度建模工具，帮助理解和调整造粒过程，这是制造洗涤剂、消费品、药品、农用化学品和特种材料新产品和交付形式的重要一步。本文的工作重点是建立一个有效的、耦合的离散元方法(DEM)/粒子数平衡(PB)计算模型，用于预测双轴浆式造粒机中颗粒尺寸和含液量的演变。本项目的具体目标是：1.开发一个能够预测喷雾区内粒子速度场和停留时间的DEM模型。驻留时间预测将根据相同系统的高速视频驻留时间分布和正电子发射粒子跟踪(PEPT)数据进行验证。开发多维种群平衡模型来预测颗粒大小和液体含量的演变，并用实验室尺度的多维颗粒分布测量来验证该模型；3.将DEM和PB模型连接到一个串联的多尺度框架中，并使用组合模型来预测实验室规模造粒机和宝洁造粒中试工厂的性能。这里提出的工作主要针对种子颗粒的分层生长。这项工作是开发包括微粉成核、致密、结合和破碎在内的完全通用的多尺度模型的更大努力的一部分。智力优势：这项提议是开发用于设计造粒过程的多尺度模型并用实验室和中试尺度的多维分布数据验证该模型的第一次认真尝试。这是颗粒处理中一类具有挑战性的问题，因为在致密颗粒流和颗粒生长过程之间存在非常强的双向耦合。这项研究的科学原创性和意义包括：-在理解宏观尺度现象的DEM模型预测对颗粒假定的力学性质的敏感性方面特别注意；-首次将喷雾区的正确物理纳入人口平衡的分层动力学表达式；-使用双向串联集成的多尺度框架对DEM和PB模型集成进行开创性研究；和-独特和实质性的实验验证和设计模型的应用于中试规模运行。广泛的影响：多尺度建模方法将推广到所有湿法制粒系统。这些模型将极大地改变这些流程的设计方式。目前，大多数造粒工艺都是通过反复试验来设计的，这会造成材料的大量损失，更不用说时间、潜在利润和产品效果了。为工程师提供工具，使他们能够更准确地设计和控制造粒操作，将对所有制造消费品和食品、药品和农用化学品的行业产生影响。拟议目标的成功完成将使湿法制粒从一门艺术变成一门可预测和可量化的科学。该项目将在多个层面上产生重大的教育影响：K-12演示的学习材料(由普渡大学社区服务计划工程项目的本科生开发)，核心本科课程，以及行业短期课程。这些教育工具以及简化的建模工具将通过www.pharmahub.org上独特的网络空间社区与国际社会共享。该项目还为研究生提供了出色的培训，包括行业实习。

The goal of the project is to develop fundamentally-based, multiscale modeling tools that will aid in the understanding and scaling of granulation processes, an important step in the manufacture of new products and delivery forms in detergents, consumer goods, pharmaceuticals, agricultural chemicals and specialty materials. The proposed work focuses on developing a validated and coupled discrete element method (DEM) / population balance (PB) computational model for predicting the evolution of granule size and liquid content in a dual axis paddle granulator. Specific objectives of this project are to:1. Develop a DEM model that can give predictions of particle velocity fields and residence times in the spray zone. The residence time predictions will be validated against high speed video residence time distributions and Positron Emission Particle Tracking (PEPT) data for an identical system.2. Develop a multidimensional population balance model to predict the evolution of granule size and liquid content, and validate this model with laboratory scale measurements of multidimensional granule distributions;3. Link the DEM and PB models in a serially integrated multiscale framework and use the combined model to predict performance in a lab scale granulator and the Procter and Gamble granulation pilot plant. The work proposed here primarily targets layered growth of seed granules. This work is part of a larger effort to develop a fully generalized multiscale model including nucleation, densification, coalescence, and breakage of fine powders.Intellectual Merit:This proposal is the first serious attempt to develop a multiscale model for design of granulation processes and validate the model with multidimensional distribution data at laboratory and pilot scales. This is a challenging class of problems in particulate processing because there is very strong two way coupling between the dense particulate flows and the granule growth processes.The scientific originality and significance of the research includes:-Special care in understanding the sensitivity of the DEM model predictions of macroscale phenomena to assumed mechanical properties of the granules;-Incorporating for the first time the correct physics of the spray zone into layering kinetic expressions for the population balance;-A pioneering study of DEM and PB model integration using a two way serially integrated multiscale framework; and-Unique and substantial experimental validation and application of the design models to pilot scale operation.Broader Impact:The multiscale modeling approach will be generalizable to all wet granulation systems. The models will dramatically transform the way these processes are designed. Currently, most granulation processes are designed by trial and error resulting in significant loss of materials, not to mention time, potential profits, and product effectiveness. Giving engineers the tools that allow them to more accurately design and control granulation operations will have impact over all industries that manufacture consumer and food products, pharmaceuticals, and agricultural chemicals. Successful completion of the proposed objectives will move wet granulation from an art, to a predictable and quantifiable science. This project will have a substantial educational impact at many levels: learning materials for K-12 demonstrations (developed by undergraduates in the Engineering Projects In Community Service program at Purdue), core undergraduate curricula, and industry short courses. These educational tools, as well simplified modeling tools, will be shared with the international community through the unique cyberspace community on www.pharmahub.org. The project also provides excellent training for a graduate student including an industry internship.