Residence times in fluidized beds with secondary gas injection

被引：33

作者：

Christensen, D. ^{[1
]}

Nijenhuis, J. ^{[1
]}

Van Ornmen, J. R. ^{[1
]}

Coppens, M. -O. ^{[1
]}

机构：

[1] Delft Univ Technol, Fac Sci Appl, DelftChemTech, NL-2628 BL Delft, Netherlands

来源：

POWDER TECHNOLOGY | 2008年 / 180卷 / 03期

关键词：

secondary injection; fluidized bed; residence time distribution; fractal injector; experimental method;

D O I：

10.1016/j.powtec.2007.02.021

中图分类号：

TQ [化学工业];

学科分类号：

0817 ;

摘要：

Experiments were carried out to determine the effects of secondary gas injection on the gas residence time and macromixing characteristics in a bubbling fluidized bed. Primary gas is introduced via a bottom distributor plate, while secondary gas is introduced via a fractal injector submerged in the bed. Results indicate that the average residence time decreases only slightly. Calculated overall reactor Peclet numbers indicate that the gas experiences less back-mixing with secondary gas injection. The bubble size was observed to decrease by up to 70%, indicating improved gas-solid contact. Taking this improved contact and plug flow behavior into account, the conversion in a fluidized bed with secondary gas injection is expected to increase significantly, particularly for mass-transfer limited reactions. (c) 2007 Elsevier B.V. All rights reserved.

引用

页码：321 / 331

页数：11

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