Correlation between conductivity and liquid hold-up for a multi-segment industrial foam probe for fermentation

被引:5
作者
Varley, J
Boyd, JWR
Gallagher, S
Brown, AK
Dodd, PW
机构
[1] Univ London Imperial Coll Sci Technol & Med, Dept Chem Engn & Technol, London SW7 2AZ, England
[2] Avecia, Billingham, Cleveland, England
[3] Charis Technol, Maidstone, Kent, England
关键词
conductivity; foam probe; fermentation; liquid hold-up;
D O I
10.1016/j.bej.2004.02.008
中图分类号
Q81 [生物工程学(生物技术)]; Q93 [微生物学];
学科分类号
071005 ; 0836 ; 090102 ; 100705 ;
摘要
In this paper we describe the use of a multi-segment conductivity probe for measuring conductivity as a function of height and time in a foam phase. Relationships between the conductivity ratio (ratio of conductivity in a foam to conductivity in the bulk liquid) and the liquid hold-up in the foam have been described previously by a number of researchers. If conductivity measurements from the multi-segment probe could be interpreted in terms of liquid hold-up in the foam this would provide valuable information about the physical nature of foam in, for example, a fermentation process, in which foams are known to have a number of adverse effects. Conductivity ratios have been determined for two multi-segment probes (one measures over a rectangular section of foam central to a cylindrical vessel, whilst the other measures over a disk like slice of foam). Liquid hold-up was measured using a specially designed column, which allows selected sections of foam (corresponding to segments on the foam probe) to be collected and weighed for determination of liquid content. A range of solutions and process parameters were used to generate foams with a range of structures and liquid hold-ups. At low values of liquid hold-up (<0.04), the conductivity ratios could be predicted well by Lemlich's equation, which assumes that all the liquid is in the Plateau borders irrespective of process conditions (although there was a concentration dependence for the two BSA concentrations considered). At higher values of liquid hold-up, data were generally better predicted by an equation, which is an interpolation between Lemlich's equation (valid in the dry limit) and Maxwell's equation (valid for higher liquid hold-ups). These results should be useful in allowing prediction of dynamic changes in liquid hold-up as a function of foam height from conductivity ratios determined using a multi-segment conductivity probe similar to the fermenter probe described here, in fermentation processes. (C) 2004 Elsevier B.V. All rights reserved.
引用
收藏
页码:199 / 210
页数:12
相关论文
共 11 条
[1]   ELECTRICAL-CONDUCTIVITY AND THE DISTRIBUTION OF LIQUID IN POLYHEDRAL FOAM [J].
AGNIHOTRI, AK ;
LEMLICH, R .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 1981, 84 (01) :42-46
[2]   An improved method for controlling foams produced within bioreactors [J].
Brown, AK ;
Isbell, C ;
Gallagher, S ;
Dodd, PW ;
Varley, J .
FOOD AND BIOPRODUCTS PROCESSING, 2001, 79 (C2) :114-121
[3]  
CHANG KS, 1979, J COLLOID INTERF SCI, V73, P224
[4]   THE ELECTRICAL CONDUCTIVITY OF FOAM [J].
CLARK, NO .
TRANSACTIONS OF THE FARADAY SOCIETY, 1948, 44 (1-2) :13-15
[5]  
DAYTE AK, 1983, INT J MULTIPHASE FLO, V9, P627
[7]   SEMITHEORETICAL EQUATION TO RELATE CONDUCTIVITY TO VOLUMETRIC FOAM DENSITY [J].
LEMLICH, R .
INDUSTRIAL & ENGINEERING CHEMISTRY PROCESS DESIGN AND DEVELOPMENT, 1985, 24 (03) :686-687
[8]   DIRECT AND ELECTRICAL-CONDUCTIVITY MEASUREMENTS OF THE LIQUID CONTENTS IN STEADY-STATE FOAMS [J].
MALYSA, K ;
KHRISTOV, K .
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 1994, 87 (02) :125-132
[9]   The conductivity of a foam [J].
Phelan, R ;
Weaire, D ;
Peters, EAJF ;
Verbist, G .
JOURNAL OF PHYSICS-CONDENSED MATTER, 1996, 8 (34) :L475-L482
[10]   Time evolution of aqueous foams: drainage and coarsening [J].
Saint-Jalmes, A ;
Langevin, D .
JOURNAL OF PHYSICS-CONDENSED MATTER, 2002, 14 (40) :9397-9412