Mass Transfer and Flow in Rotary Gas-Liquid Contactors (Industry-University Cooperative Project)

研究综述：在填充床旋转装置中可以实现更高的传质速率，其中液体由于重力而获得的加速度是重力的数倍。在许多领域都有潜在的商业应用。本研究的目的是为气液接触旋转装置的放大、操作和设计提供合理的依据。为了实现这一目标，首先研究了易表征固体表面的转子内液膜的形状、结构、速度分布和稳定性。然后，采用穿透模型或对流扩散模型，推导出适用于传质系数的表达式，包括固体表面随机分布的统计模型。这为扩大规模提供了合理的基础。旋转填充床中的液含率和质构是用改进的电导法测量的，从而提供了关于这些设备中液膜流动特性的额外信息。科学新颖性。这项研究有两个新的特点，(1)系统地使用在已知几何形状的设备中产生的健全的基本知识来生成设备的设计程序，否则很难表征设备的特性；(2)发展了一种改进的电导法来测量旋转设备中的液体上升和织构。这样的测量通常是困难的。实际影响和技术影响。这项工作将为该装置的设计提供坚实的基础，从而增加该装置的潜在商业应用。预计该装置将在高纯度特种化学品中得到应用，而这些化学品在传统设备中往往不容易生产。另一个潜在的应用是聚合中的单体剥离。此外，展望未来，有必要开发在失重或零重力环境下外层空间气液接触的设备。拟议的研究将有助于实现上述许多可能性。

Research Summary: Higher mass transfer rates can be achieved in packed bed rotary devices where the liquid attains an acceleration many times that due to gravity. There are potential commercial applications in many fields. The objective of the proposed research is to provide a rational basis for the scaleup, operation and design of rotary devices for gas-liquid contacting. To accomplish this goal, the shape, structure, velocity profile and stability of liquid films in rotors of readily characterizable solid surfaces is first examined. The penetration model or the convection-diffusion model is then adapted to develop suitable expressions for the mass transfer coefficients, including a statistical model for random distribution of solid surfaces. This provides a rational basis for scaleup. Liquid holdup and texture in the rotating packed beds is measured by a modified electrical conductivity method thereby providing additional information on the characteristics of liquid film flow in these devices. Scientific Novelty. The research has two novel features, (1) systematic use of sound fundamental knowledge generated in equipment of known geometry to generate design procedures for equipment which are otherwise difficult to characterize, (2) development of a modified electric conductivity method for measurement of liquid-up and texture in rotating equipment. Such measurements are normally difficult. Practical and Technical Impact. The work will provide a firm basis for design and thereby increase potential commercial applications of this device. It is expected that the device would find application in high purity specialty chemicals which cannot be often readily produced in traditional equipment. Another potential application is in monomer stripping in polymerizations. Moreover, as one looks into the future, there is a need to develop equipment for gas-liquid contacting in outer space under reduced or zero gravity environment. The proposed research will facilitate the realization of many of the above possibilities.