Liquid side flow characteristics in a packed absorption column

Abstract

This thesis is primarily concerned with the study of techniques which enable flow conditions in complex geometrical arrangements to be measured and analysed. The liquid side in a packed absorption tower is chosen to illustrate the principles involved. The analysis of disturbance testing involves the evaluation of the moments of the resulting residence time distribution curves. It has in the past been found that this method often produces misleading results due to the magnification of experimental errors. An improved method of moment analysis is introduced in this work in an attempt to lessen this effect. It is also shown that much more useful information can be obtained by measuring the response to a disturbance at a number of selected positions in the bed rather than a single determination at the outlet from the column. Two mathematical models are chosen to describe the observed flow situation. The values of their characteristic parameters, as determined from the disturbance testing, are shown to exhibit a number of interesting features which enhance our knowledge of liquid side flow conditions. Finally, a technique is introduced to study flow behaviour from chemical reaction data. The experimental results obtained are shown to agree very closely with theoretically derived values.