GAS RECIRCULATION RATE THROUGH IMPELLER CAVITIES AND SURFACE AERATION IN SPARGED AGITATED VESSELS

被引：29

作者：

NIENOW, AW

CHAPMAN, CM

MIDDLETON, JC

机构：

[1] Department of Chemical and Biochemical Engineering, University College London, London, WC1E 7JE, Torrington Place

[2] ICI Corporate Research Laboratories, The Heath, Runcorn

来源：

CHEMICAL ENGINEERING JOURNAL AND THE BIOCHEMICAL ENGINEERING JOURNAL | 1979年 / 17卷 / 02期

关键词：

D O I：

10.1016/0300-9467(79)85004-2

中图分类号：

TQ [化学工业];

学科分类号：

0817 ;

摘要：

A novel method for determining gas recirculation rates through impeller cavities in sparged agitated vessels is described. It is based on the withdrawal, particularly from the cavities themselves, of gas samples forsubsequent analysis. Oxygen is used as the tracer gas and nitrogen for sparging. The method can also be used for determining surface aeration rates. The method gives values for the external distribution coefficient α (=QR/QS) of between 0 and 1. These values agree well with those calculated from power measurements at high impeller speeds N > NR. However, the method also suggests that recirculation occurs at N < NR but in this region the method is not entirely valid. The measurements of surface aeration clearly show that attempts to relate the effect of surface aeration without sparging to the sparged condition are unsatisfactory. © 1979.

引用

页码：111 / 118

页数：8