Effect of liquid addition on heat transfer in gas-fluidized beds of large light particles
Effect of liquid addition on heat transfer in gas-fluidized beds of large light particles
复制标题
液体添加对大轻颗粒气体流化床传热的影响
DOI：
10.1243/095440803322611642
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
A. Yokogawa
中科院分区：
文献类型：
--
作者：
Y. Nagahashi;J. Grace;Y. Asako;N. Epstein;D. H. Lee;A. Yokogawa
在液体密度与颗粒密度相近的大颗粒气体流化床中加入液体，可使流化速度范围和流化强度大幅度增加。在本文中，它表明，这也导致强烈的床和浸没管之间的传热增强。在聚苯乙烯颗粒或玻璃珠的空气流化床中使用外径为25 mm的加热管进行实验，向其中加入少量水（通常相当于床体积的10%）。从传热实验的结果进行了解释的帮助下，使用位于管内的工业内窥镜的管表面的观察。强化传热的关键因素被确定为液-固聚集体的热传导、液相的对流、气相的对流和汽化。
Abstract When liquid is added to large-particle gas-fluidized beds where the liquid density is similar to the particle density, the liquid addition can cause a dramatic increase in the velocity range and intensity of fluidization. In this paper it is shown that this also leads to strong enhancement of the heat transfer between the bed and an immersed tube. Experiments were carried out using a heated tube of outer diameter 25 mm in air-fluidized beds of polystyrene particles or glass beads to which small quantities of water (typically equivalent to 10 per cent of the bed volume) were added. The results from the heat transfer experiments are explained with the aid of observations of the tube surface using an industrial endoscope located inside the tube. The key factors underlying the enhancement of heat transfer are identified to be heat conduction to liquid-solid aggregates, convection to the liquid phase, convection to the gas phase and vaporization.