Non-isobaric bubble columns with variable gas velocity

✍ Scribed by Wolf-Dieter Deckwer

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 815 KB
• Volume: 31
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(76)85076-2

✦ Synopsis

When designing bubble columns two major uncertainties are encountered, viz. the reliable estimation of parameter values and the application of the pertinent design model. This paper presents a design model which on the base of the dispersion model accounts for the opposite effects of gas shrinkage and expansion caused by absorption and reduced hydrostatic head, respectively. As the holdup of the phases can be assumed to be axially independent the gas velocity is variable. Therefore, the differential equations are non-linear and were solved by the method of Lee.

Computed profiles show that the gas concentration may run through a minimum. The calculations reveal that the neglect of a variable gas velocity may yield serious errors even at isobaric conditions. The influence of gas phase dispersion is marked in large diameter bubble columns. Worked examples are given for the case of a fast and slow reaction in the liquid phase which are compared with the predictions of a simpler model.