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Ist hydrodynamische Modellierung tragfähig für die Auslegung von Schwerkraftabscheidern ohne Einbauten?
Author(s) -
Blaß Eckhart,
Löbmann Arthur,
Meon Walter,
Rommel Wolfgang
Publication year - 1989
Publication title -
chemie ingenieur technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.365
H-Index - 36
eISSN - 1522-2640
pISSN - 0009-286X
DOI - 10.1002/cite.330610807
Subject(s) - coalescence (physics) , liquid phase , dispersion (optics) , mechanics , materials science , physics , thermodynamics , optics , astrobiology
Is hydrodynamic modelling a sound approach for the design of gravity settlers without coalescing aids? Liquid/liquid dispersions occur in many chemical operations. Normally they have to be broken down again. This is accomplished by the flowing together of the droplets (coalescence) to a coherent phase. In practice simple gravity settlers without any coalescing aids are used for this purpose. In such settlers the dispersion is separated by the density difference between the phases, while a dense dispersion layer forms at the interface between the dispersion and the clear mother phase. The present paper deals with the modelling of such gravity settlers. First, the models describing the coalescence process of single drops are reviewed and analyzed. A physical notion of the coalescence process is derived thereform. Afterwards the models for the droplet coalescence in dense dispersions taken from the literature are presented and discussed. In conclusion the chances and limitations of the present settler models are indicated by quantitative comparison of selected models. A computer program specially developed for this purpose is presented.