Method and apparatus for gas cooling

Abstract

A low energy consumption apparatus and method for treating a gas in which a main gas stream is cooled and heat is transferred by convection to a liquid and a secondary gas stream across a heat transfer surface. Liquid bearing the heat evaporates into the secondary stream. A total gas stream is subjected to initial cooling along a moisture impervious surface of a heat exchange element to cause dry or sensible cooling. A secondary gas stream is diverted from the total discharge from the dry cooling stage and is directed counterflow to the total stream at the opposite surface of the heat exchange element which is an absorbent surface to cause heating and humidification of the secondary stream. The remaining cooled stream which is the primary stream is subjected to sorbent treatment to heat and dehumidify the same by flowing it through an absorbent media. The primary gas flow is then subjected to a final heat exchange treatment stage similar to the initial heat exchange treatment. Condensate may be removed from the saturated or near-saturated secondary flow. The primary flow may also be subjected to intermediate cooling treatment. A portion of the initial and final dry cooling stages preferably include an adiabatic cooling zone. The secondary flow from the initial heat exchanger may be subdivided into two streams. One secondary sub-stream is dehumidified in the sorbtion device by an auxiliary heater and is used for regeneration of the absorbent media.