GOALI: Measurement of Stresses in Bulk, Flowing Powders and Application to Scale-Up of Powder Processes

GOALI：散装、流动粉末中应力的测量及其在粉末工艺放大中的应用

• 批准号: 0355417
• 负责人: Gabriel Tardos
• 金额: --
• 依托单位: CUNY City College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-15 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0355417&HistoricalAwards=false
• 关键词: GOALI; Measurement; Stresses; Bulk; Flowing

AbstractCTS-0355417G. Tardos, CUNY City CollegeThe proposal addresses the key issue of force-and stress-measurements in dry or wet (cohesive) moving (flowing) powders in several unit operations and the application of stress-measurement criteria to scale-up in different kinds of powder processing equipment. We propose to use the method of calibrated test particles of known yield strength to interrogate forces (stresses) in the bulk of the moving powder and to capture the point where the stresses on the particle equals its yield strength and starts to deform. Scale-up to larger size machines of the same or different geometry is then achieved by adjusting the operating conditions in the larger machine so as to achieve stresses of equal magnitude. Preliminary work on wet granulation in a vertical-axis mixer-granulator (see also Tardos et al., 2003b) has clearly shown the feasibility of such an approach and has demonstrated that using this kind of scale-up rule yields product of similar properties at both scales. This was the first time that forces in a cohesive, flowing powder were measured on freely moving objects inside the bulk. The main goal of the proposed research is to show that this kind of measurement is general to many different powder-flow systems and to apply it to the most common and most difficult applications such as mixers, granulators of different kinds, fluidized beds and rotating drums containing both wet and dry powders. The involvement of the industrial partner in this research is crucial since it will allow, on one hand, use of existing modern instrumentation and large-size industrial equipment during the project, and on the other hand, direct use of the knowledge gained in several industrial processes specifically in pharmaceutical applications. In addition, the co-PI is a very well known Powder Technologist (a former university professor himself) that will contribute greatly to advising students, directing the research and disseminating the knowledge gained at the industrial site and at conferences. Intellectual Merit The proposed research is aimed at substantially improving understanding in an area of Powder Science and Technology where precise measurements and basic knowledge were slow to develop due to the extreme complexity of underlying phenomena and the difficulty in experimentation. The area is however of great industrial relevance especially scale-up of powder-flow processes in different equipment where large amounts of time and funds are presently spent. The proposed measuring method, if successfully developed and generalized, will give industry a real, practical tool to undertake scale-up even of equipment that is geometrically dissimilar. This will be the first time that such a tool will be generally available to industrial practitioners. It will enable the transfer of powder processes from different types of equipment assuring constant product attributes by keeping internal stresses in the bulk powder constant. Broader Impact The research will have very broad academic and industrial impact due to its dual location as an industry-academy type research project. Both groups will use and disseminate information in their respective communities by actually applying the obtained results and by presenting them widely at conferences, seminars and symposia. The graduate and undergraduate students will be trained in a relatively unknown and mostly under-funded branch of engineering where progress has been slow and relatively few trained practitioners exist. In addition, small amount of funds are requested to support high school students (juniors and seniors) who attend the college routinely in the framework of a high-school-university exchanges program (SPICE) that is in operation at the college for at least ten years. This project will enable these students to try their hand in this relatively unknown field. Finally, since CCNY qualifies as a minority institution. 50-60% of students involved in all aspects of the research will be underrepresented minorities and they will actively participate in the project at all levels.

摘要CTS-0355417G。城市大学塔尔多斯学院该提案解决了几个单元操作中干或湿(粘性)移动(流动)粉末的力和应力测量的关键问题，以及应力测量标准在不同类型粉末加工设备中的放大应用。我们建议使用已知屈服强度的校准测试颗粒的方法来询问移动粉末中的大部分力(应力)，并捕捉颗粒上的应力等于其屈服强度并开始变形的点。然后，通过调整较大机器中的操作条件来实现相同或不同几何形状的较大尺寸机器的放大，以获得相同大小的应力。关于垂直轴混合机-造粒机中湿法制粒的初步工作(另见Tardos等人，2003b)清楚地表明了这种方法的可行性，并证明了使用这种放大规则在两种尺度下都能产生性质相似的产品。这是第一次测量粘性、流动的粉末中的力对散体内自由移动的物体的作用力。这项研究的主要目的是表明这种测量方法对许多不同的粉末流动系统是通用的，并将其应用于最常见和最困难的应用，如混合器、不同类型的造粒机、包括湿粉和干粉的沸腾床和旋转转鼓。工业伙伴参与这项研究是至关重要的，因为这一方面将允许在项目期间使用现有的现代仪器和大型工业设备，另一方面将直接使用在几个工业过程中获得的知识，特别是在制药应用中。此外，合作者是一位非常知名的粉末技术学家(他本人也是一名大学教授)，他将为指导学生、指导研究和传播在工业现场和会议上获得的知识做出巨大贡献。智力价值拟议的研究旨在大幅提高对粉末科学和技术领域的理解，在该领域，由于潜在现象的极端复杂性和实验的困难，精确的测量和基础知识发展缓慢。然而，这一领域具有很大的工业意义，特别是扩大不同设备中的粉末流动过程，目前正在花费大量的时间和资金。拟议的测量方法如果成功开发和推广，将为工业提供一个真正实用的工具，即使是几何上不同的设备也可以进行放大。这将是工业从业者第一次普遍使用这种工具。它将允许从不同类型的设备转移粉末工艺，通过保持散装粉末中的内应力恒定来确保产品属性的恒定。更广泛的影响由于其作为产学院式研究项目的双重定位，该研究将具有非常广泛的学术和产业影响。这两个小组将通过实际应用所取得的成果并在会议、研讨会和专题讨论会上广泛介绍，在各自的社区使用和传播信息。研究生和本科生将在一个相对不知名、大多资金不足的工程学分支接受培训，那里的进展缓慢，训练有素的从业者相对较少。此外，还要求提供少量资金，以支持在该学院实施了至少十年的高中-大学交流计划(SPICE)框架内定期进入该学院学习的高中生(三年级和四年级)。这个项目将使这些学生能够尝试进入这个相对陌生的领域。最后，由于CCNY有资格成为一家少数族裔机构。参与研究各个方面的学生中，50%-60%将是代表性不足的少数族裔，他们将积极参与各个级别的项目。