Regime transition in bubble columns: experimental and predictions

• Published in: Experimental thermal and fluid science Vol. 28; no. 5; pp. 423 - 430
• Main Authors: Thorat, B.N., Joshi, J.B.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.04.2004; Elsevier Science
• Subjects: Applied sciences; Bubble column; Chemical engineering; Exact sciences and technology; Heterogeneous regime; Homogeneous regime; Linear stability; Reactors; Sparger design; Transition; Transition; Linear stability; Sparger design; Heterogeneous regime; Homogeneous regime; Bubble column; Design; Gas liquid; Gas holdup; Flow regime; Theoretical study; Experimental study; Reactor
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2003.06.002

The present paper examines the effects of sparger design and dispersion height on the regime transition. Experiments were performed in a 0.385 m i.d. bubble column. Twenty-two designs of sieve plate spargers were employed. Free area was varied in the range of 0.136–5.0% and the hole diameter was varied in the range of 0.8–50 mm. The height to diameter ratio was varied in the range of 1–8. The effect of coalescing nature of the liquid phase was also investigated. In order to reduce the coalescing behavior as compared to air–water system, aqueous solution of 0.2 M NaCl formed the liquid phase. For enhancing the coalescing behavior, the liquid phase was 1% (w/w) solution of carboxy methyl cellulose. A mathematical model has been developed for the prediction of critical gas hold-up on the basis of linear stability analysis. A comparison has been presented between the model prediction and the experimental observations.