Froth-emulsion transition

Froth-Emulsion Froth-emulsion transition occurs [Hofliuis and Zuiderweg, I. Cherrt. E. Symp. Ser. 56, p. 2, 2/1 (1979)] when the aerated mass begins to obey the Francis weir formula. Using this criterion, the latest version of this transition correlation is... 

Flow regime. Since the trays are unlikely to operate in the spray regime (Sec. 6.4.2), it is best to first examine the froth-emulsion transition. This check requires using the Hofhuis correlation for clear liquid height (Sec. 6.3.5). 

Comment All the actual flow parameters exceed the flow parameters at the froth-to-emulsion transition. Therefore, all these checks indicate emulsion regime operation. 

The transition from the spray regime to mixed froth-emulsion flow is described by FP > 3.0/ /z ... 

Effect of fractional hole area. Low fractional hole areas increase the tendency of trays to operate in the spray regime (92,106), In terms of Fig. 6.29, lower fractional hole areas tend to shift the spray-froth boundary to the right. No effect of fractional hole area was observed (17,85) on the transition from the froth to the emulsion regime. 

While the classical hydraulic model provides a reasonable approximation for the froth and emulsion regimes, different mechanisms determine the hydraulics and mass transfer in the spray regime. The transition from froth to spray is gradual, and so is the change in the hydraulic and mass transfer behavior (110,111,113,114). 

---