Fluids Inspired Granular Processing: Novel methods of mixing and separation

受流体启发的颗粒加工：混合和分离的新方法

• 批准号: 0933358
• 负责人: Joseph McCarthy
• 金额: $ 30万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0933358&HistoricalAwards=false
• 关键词: Fluids; Inspired; Granular; Processing; Novel

0933358 McCarthy Despite recent advances, particle processing still lags significantly behind its counterpart of fluid processing. The unifying theme of this proposal is the adaption of concepts from fluid processing in order to develop novel techniques for particle applications. Specifically, we target the mixing of dissimilar materials in surface flows of cohesionless (free flowing) materials as well as novel particle separation techniques. The underlying hypothesis of the first focus area of this work is that by exploiting flow perturbations a technique with a long history in fluid processing we can develop, for the first time, a general method for limiting particle segregation in free flowing systems, perhaps the most common and well studied of granular flows. The key to this approach lies in recognizing that it takes a finite time for material to segregate and that there is always a preferred direction that particles tend to segregate. In order to exploit these two facts, one needs to perturb the flow at a high frequency and in such a way that the surface layer is inverted. Particle separations techniques are typically quite low tech and often are energy intensive (e.g., sieving) or environmentally unfriendly (e.g., froth floatation) or both. The underlying hypothesis of the second focus area of this work is that we can develop rate based separations techniques based on granular temperature driven segregation and non-equipartition of (granular) energy. Specifically, we aim to build an analog of a granular chromatograph using a shaking table that imparts a gradient in vibration energy and hence, a gradient in granular temperature. Additionally, we plan to explore granular ratchets in analogy to Brownian ratchets from microfluidic studies because non equipartition of energy will yield the equivalent of the species dependent diffusion coefficient necessary for ratcheting to function for separations. These fluids inspired particle separations devices should not only overcome several of the shortcomings of traditional particle separations techniques, but also will help to validate kinetic theory based models in a very practical context. The chief intellectual merit of this work will be evidenced through advancing knowledge and understanding across fields of engineering and physics via: 1. Expanding our preliminary mixing results past the proof of concept stage and into a general methodology for limiting both single (density or size) and mixed mode segregation in a variety of surface dominated flows, including developing a set of validating experimental and simulation results that demonstrate the utility of flow perturbations for limiting segregation. 2. Establishing design heuristics for segregation free operation of a variety of particle processing devices. 3. A series of experiments that can be used as a test bed for variations on kinetic theory expressions. 4. Two novel particle separation devices: a granular chromatograph and a granular ratchet apparatus The primary broader impacts will be related to the economic impact on the wide variety of industries that deal with particle processing for whom mixing/segregation and particle separation have dramatic product/revenue implications. Additional broader impacts of the work lie in integrating teaching and research. This teaching/research integration will take two forms: training of two graduate students and several undergraduate researchers (with emphasis on under represented groups), and the development of a novel handson K-12 teacher training/partnership program focused on building interest in science in disadvantaged youths. Coupling a particle technology researchers natural propensity for hands-on instruction with a desire to have a positive impact on the the disadvantaged youth in the local community, the PI is proposing to form a partnership with the Academy Charter School (http://www.theacademysystem.com). This 8-12 grade school is the only charter school in the US exclusively focused on educating court ejudicated youth. Hands-on or inquiry based science education has been shown to not only improve student attitudes toward science, but also to foster higher overall achievement as well as a more flat response as a function of demographic background. The proposed partnership will comprise workshop like sessions between the PI and instructors in the Academy Charter School aimed at developing and/or adapting inquiry based educational modules suitable for science/engineering education in this unique learning environment highly competitive nature of the proposals submitted to the Program and the panel recommendation, the Program Director recommends that this proposal be awarded.

0933358麦卡锡尽管最近进步，但粒子加工仍然显着落后于其流体加工的对应物。 该提案的统一主题是从流体加工中适应概念，以开发用于粒子应用的新技术。具体而言，我们针对无内聚力（自由流动）材料的表面流以及新颖的粒子分离技术的混合。这项工作的第一个焦点领域的基本假设是，通过利用流动扰动，一种具有悠久流体处理历史的技术，我们可以首次开发一种限制自由流动系统中粒子隔离的一般方法，这可能是最常见的和精心研究的细菌流量。这种方法的关键在于认识到材料隔离需要有限的时间，并且总是有一个首选的方向粒子倾向于隔离。为了利用这两个事实，需要以高频和表面层倒置的方式扰动流量。粒子分离技术通常是非常低的技术，通常是能量密集型（例如，筛分）或环境不友好的（例如，泡沫浮动）或两者兼而有之。这项工作的第二个重点区域的基本假设是，我们可以根据颗粒温度驱动的分离和（粒状）能量的非估算方法开发基于速率的分离技术。具体而言，我们旨在使用摇动桌子来构建颗粒色谱的类似物，该表在振动能量中赋予梯度，因此，在颗粒温度下梯度。此外，我们计划与微流体研究类似于布朗棘轮的颗粒状棘轮，因为不可偶联的能量将产生相当于棘轮依赖的物种依赖的扩散系数，以使分离功能起作用。这些流体启发的粒子分离设备不仅应克服传统粒子分离技术的几个缺点，而且还将有助于在非常实用的背景下验证基于动力学理论的模型。这项工作的主要智力优点将通过以下方式通过：1。扩大概念验证阶段的验证验证验证阶段，并限制单个（密度或大小）和混合模式隔离的一般方法，在各种表面上占主导地位的流动中，将有效的实验性验证的限制验证验证的限制性验证。 2。建立设计启发式方法，用于各种粒子加工设备的无隔离操作。 3。一系列实验，可以用作测试床，以进行动力学理论表达式的变化。 4。两个新型的粒子分离装置：颗粒色谱和颗粒状棘轮设备。主要的广泛影响将与对涉及粒子处理的各种行业的经济影响有关，这些行业与粒子处理具有巨大的含义/收入的影响。这项工作的其他更广泛的影响在于整合教学和研究。这种教学/研究整合将采取两种形式：对两名研究生和几位本科研究人员进行培训（重点是代表群体），以及开发一项新颖的Handson K-12教师培训/伙伴计划，重点是在弱势青年中建立科学兴趣。 PI耦合了粒子技术研究人员的自然倾向，以对当地社区中处境不利的年轻人产生积极影响，PI提议与学院宪章学校（http://www.theacademysystem.com）建立合作伙伴关系。 这所8-12小学是美国唯一专注于教育法院驾驶青年的特许学校。已经证明，基于动手或询问的科学教育不仅可以提高学生对科学的态度，而且还可以促进更高的整体成就，以及作为人口统计背景的函数的更平坦的反应。拟议的合作伙伴关系将包括PI和学院特许学校的讲师之间的课程，旨在在这个独特的学习环境中开发和/或适用于基于询问的教育模块，适用于科学/工程教育，高度竞争性的竞争性质，提交给该计划的建议和小组建议，该计划主任建议该计划授予该建议。