撞击流性质及其应用

Properties and Application of Impinging Streams

撞击流已被证明是强化相间热质传递最有效的方法之一 ;但不可能是一种万能的工具 ,因为它也有其本身的局限性。在回顾前人和本文作者一系列研究结果的基础上 ,综合评价了撞击流的基本特性 ,包括优点和缺点 ,诸如气固系统阻力不大、传递系数大、混合强烈、活性区停留时间很短以及难以安排多级系统等。简要介绍了撞击流工业应用现状和某些有希望成功的开发研究 ,包括本文作者所作的循环撞击流干燥过程和撞击流反应制“超细”

Impinging Streams (IS) has been proved to be one of the most effective methods enhancing heat and mass transfer between phases, and thus exhibits potential for application. IS can not be a universal tool, however, for it has some major disadvantages, too. It is important for proper application to understand its behaviors.Summarizing a number results worked by the author of the present paper and others, the essential properties of IS, advantages and disadvantages, such as medium resistance to gas solid suspension flow, high transfer coefficients, strong mixing, very short mean residence time in active region, and difficulty in arranging multistage process, etc., are evaluated.The status and some new developments of IS industrial application hopeful to be success are reviewed, including those worked by the author, e.g., drying of PVC in a circulative IS dryer and preparation of 'ultra fine' white carbon black in a submerged circulative IS reactor.