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

abstractcts - 0355417 g。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，以及在不同种类的粉末加工设备中应用应力测量标准的放大。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体中的力（应力），并捕获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，从而实现相等大小的应力。在垂直轴混合造粒机中湿制粒的初步工作（参见Tardos等人，2003b）已经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个尺度上产生相似性质的产品。这是第一次测量具有粘性的流动粉末对内部自由运动物体的作用力。所提出的研究的主要目标是表明这种测量方法一般适用于许多不同的粉末流系统，并将其应用于最常见和最困难的应用，如混合器、不同种类的造粒机、流化床和含有湿粉和干粉的旋转鼓。工业伙伴参与这项研究是至关重要的，因为一方面，它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，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，联合项目负责人是一位非常知名的粉末技术专家（他本人曾是一名大学教授），他将为学生提供建议，指导研究，并在工业现场和会议上传播所获得的知识。提出的研究旨在大幅提高对粉末科学和技术领域的理解，由于潜在现象的极端复杂性和实验难度，精确的测量和基本知识发展缓慢。然而，该领域具有重大的工业意义，特别是在不同设备中扩大粉末流动过程的规模，目前需要花费大量的时间和资金。所提出的测量方法，如果成功地开发和推广，将为工业提供一个真正的、实用的工具，甚至可以对几何上不同的设备进行放大。这将是第一次，这样的工具将普遍提供给工业从业者。它将使粉末工艺从不同类型的设备转移，确保恒定的产品属性，保持内部应力在散装粉末恒定。更广泛的影响该研究将具有非常广泛的学术和产业影响，因为它的双重位置作为一个产学研类型的研究项目。这两个小组将在各自的社区使用和传播信息，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这些成果。研究生和本科生将在一个相对不为人知且资金不足的工程分支接受培训，该分支的进展缓慢，受过训练的从业人员相对较少。此外，少量资金被要求支持在学院运行至少十年的高中-大学交流计划（SPICE）框架内定期进入学院的高中生（三年级和四年级）。这个项目将使这些学生在这个相对陌生的领域尝试自己的手。最后，由于CCNY符合少数族裔机构的资格。参与研究各个方面的50-60%的学生将是代表性不足的少数民族，他们将在各个层面积极参与项目。

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.