As a first step in the study of dumping or weeping, a theoretical model for the mechanism of bubble formation has been set up. Equations have been derived for pressures involved in a single orifice bubbling system and for radial expansion of a spherical bubble. The theory has known limitations; nevertheless a fair agreement with the experiments has been found over a certain range in the 'dumping region'. A simplified model for behaviour of a sieve tray, based on the single orifice theory, has been suggested. A simplified criterion for dumping in a single orifice or a sieve tray is described. It is shown that the mean pressure in the gas chamber under a plate and the liquid pressure behind a bubble rising above a plate has considerable effects in the dumping studies. A fair qualitative analysis of the behaviour of a system for predicting different degrees in dumping rate has been made possible using the present theory. Experiments have been carried out for measuring bubble frequency, pressure fluctuations in gas chamber and dumping rates. High speed cine photographs have been taken both from a three dimensional apparatus and from a two dimensional apparatus, the latter mainly for distinct observations of the dumping phenomenon.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:623074 |
| Date | January 1968 |
| Creators | Kupferberg, Arie |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/15940 |
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