Magnetic resonance imaging of gas dynamics in the free board of fixed beds and bubbling fluidized beds

被引：5

作者：

Boyce, C. M. ^{[1
,2
]}

Rice, N. P. ^{[1
]}

Davidson, J. F. ^{[1
]}

Sederman, A. J. ^{[1
]}

Dennis, J. S. ^{[1
]}

Holland, D. J. ^{[1
,3
]}

机构：

[1] Univ Cambridge, Dept Chem Engn & Biotechnol, New Museums Site,Pembroke St, Cambridge CB2 3RA, England

[2] Princeton Univ, Dept Chem & Biol Engn, Princeton, NJ 08544 USA

[3] Univ Canterbury, Dept Chem & Proc Engn, Canterbury, New Zealand

来源：

CHEMICAL ENGINEERING SCIENCE | 2016年 / 147卷

关键词：

Fluidized beds; Freeboard; Magnetic resonance imaging; Flow measurement; ERUPTION PATTERNS; FREEBOARD; FLOW; CLASSIFICATION; BEHAVIOR;

D O I：

10.1016/j.ces.2016.03.005

中图分类号：

TQ [化学工业];

学科分类号：

0817 ;

摘要：

Magnetic resonance imaging (MRI) was used to measure directly gas velocity and gas velocity distribution in the freeboard region of a fluidized bed (52 mm dia.) under bubbling fluidisation and just below minimum fluidisation. The bed consisted of poppy seed particles 1.1 mm in diameter and was fluidized using SF6 gas at 7.5 barg for MRI purposes. In the system, bubbles approximately 20 mm in diameter rose through the centre of the bed. In the case of bubbling fluidisation, time-averaged velocity maps at different vertical positions in the freeboard showed downward moving gas in the centre of the bed and upward moving gas near the walls for this particular bed. However, below minimum fluidisation conditions, the profiles of gas velocity in the freeboard were flat, with respect to the radial dimension, with minor and random spatial variance, indicating that the profiles observed during bubbling arose from bubble breakthrough. The reasons for these observed patterns of flow are discussed. (C) 2016 Elsevier Ltd. All rights reserved.

引用

页码：13 / 20

页数：8

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