On the gas expansion and gas hold-up in vertical slugging columns - A simulation study

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Mayor, TS (Author) Other; Pinto, AMFR (Author) FEUP; Campos, JBLM (Author) FEUP

Journal

Title: Chemical Engineering and Processing - Process Intensification

Vol. 47

Pages: 799-815

ISSN: 0255-2701

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 6 Citations

ISI Web of Science

Scopus - 6 Citations

Scientific classification

FOS: Engineering and technology > Environmental engineering

CORDIS: Technological sciences ; Physical sciences

Other information

Authenticus ID: P-003-ZJP

DOI: 10.1016/j.cep.2007.01.031

Abstract (EN): A study on the gas phase expansion and gas hold-up occurring in free bubbling vertical slug flow is reported. A slug flow simulator (SFS) supported by air-water experimental data was used for this purpose. The study was accomplished by implementing in the simulator the gas phase expansion along the column. Effects over bubble lengths and bubble velocities were considered. The flow in 6.5 and 20 m long columns with internal diameter of 0.032 m was simulated. Expansion of gas phase along the column is shown to slightly decrease the occurrence of bubble coalescence. Liquid free surface oscillations (due to bubble burst events and continuous inlet of liquid and gas in the column) were found to affect the expansion of the gas phase, especially for high gas flow rates. The gas phase expansion for different outlet column configurations was studied. The use of a high and large cross sectional tank (to dampen free surface oscillations) is shown not to assure a permanent expansion rate of the gas phase. Simulations with and without gas expansion along the column were compared for the computation of average flow parameters. Approximate approaches (with constant UG, corrected for the mid-column pressure) were found suitable for the prediction of the average slug length and gas hold-up. Those approaches are, however, inadequate for the computation of the average bubble length and velocity along the vertical coordinate of the column.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 17