Direct contact heat transfer via injecting volatile liquid in a hot liquid pool: generation and motion of bubbles

TitleDirect contact heat transfer via injecting volatile liquid in a hot liquid pool: generation and motion of bubbles
Publication TypeJournal Article
Year of Publication2013
AuthorsKulkarni, AA, Ranade, VV
JournalChemical Engineering Science
Volume100
Pagination421-432
Date PublishedAUG
ISSN0009-2509
KeywordsBubble, Direct contact HT, Drobble, Drop, Evaporation, Slightly miscible liquids
Abstract

Direct contact heat transfer via injection of volatile liquid is an effective strategy for removing heat from a viscous liquid pool. The rapid evaporation effectively removes heat and the generated bubbles move quickly to the top surface. In this paper, we present an experimental and phenomenological analysis of the evaporation of a drop in a slightly miscible liquid. The phenomenon was visualized using a two-dimensional transparent experimental set-up with a single inlet at the bottom. The videos were used to estimate bubble dimensions, its rise velocity, distance from the detachment point, and fraction of vapor and the liquid phases in the evaporating drop. The initial drop size, temperature difference between the hot fluid and the low boiling solvent and the nucleation rate governed the rate of change of the drobble (combined entity of drop and bubble) diameter and its rise velocity. A phenomenological model describing transient behavior of drobble (motion and heat transfer) is developed. The transient variation in the interfacial areas for heat transfer and the projected area were found to have effect on the predictions. The model and results will also provide useful basis for extending the work towards better understanding of direct contact heat transfer in viscous systems like polymerization reactors. (C) 2013 Elsevier Ltd. All rights reserved.

DOI10.1016/j.ces.2013.02.057
Type of Journal (Indian or Foreign)Foreign
Impact Factor (IF)2.613
Divison category: 
Chemical Engineering & Process Development