Implications of the Emulsion Regime for Design and Operation

The difference in the behavior of the aerated mass between the emulsion and froth regimes is far less apparent than the difference between the froth and spray regime. 

Vapor recycle. Because of the large quantity of vapor that enters the downcomer and the difficulty of separation in the downcomer, vapor recycle is a major consideration in the emulsion regime (Sec. 6.2.8) and can lead to reduction of both capacity and efficiency, and to an increase in pressure cirop (17). 

Foaming. The emulsion flow regime is particularly sensitive to foaming (17,85). The presence of foaming impurities stabilizes the emulsion and therefore brings about a premature capacity limitation. 

Mass transfer. Tray efficiency increases with pressure in the froth regime (118,119), but decreeises with ino eased pressure in the emulsion regime (44,104,105). The efficiency decrease in the emulsion r ime is caused by the greater vapor recycle (44,104,105). In general, there is otherwise little difference between mass faransfer in the froth and emulsion regimes. 

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