1990 Volume 23 Issue 5 Pages 537-542
In a “reverse-rectification system,” a volatile liquid (water) is injected into the evaporator placed at the bottom of a packed column. A less-volatile liquid (ethylene glycol) is injected into the head of the column. In the column, vapor and liquid are contacted in countercurrent flow (glycol downfiow, water-vapor upflow). Some heat is evolved by the vapor-liquid absorption, and is extracted through a heat exchanger incorporated in the column.
Three different structures of the system are modelled and compared, by using the Ponchon diagram.
A lab-scale reverse-rectification column with an integrated glycol preheater was constructed and operated under atmospheric pressure.
The measured performance criteria are: the temperature lift, which is the difference between the temperature of the upgraded heat flux extracted from the column and that of the heat flux supplied to the evaporator, and the heal efficiency, which is the ratio of these two heat fluxes.
The temperature lift and the heat efficiency were studied as functions of the flow rates of the liquids injected at the top and the bottom of the system.
