The Absorber System

The rich solution leaves the leveling chamber and passes through the liquid heat exchanger to the pump tube. By adding heat (by means of gas or electricity) the temperature of the solution rises. This temperature increase causes ammonia and some water vapour to be driven out of the solution, forming vapor bubbles, which push columns of liquid up the pump tube. This liquid, now a weak ammonia solution, falls downward through the generator and flows through the external shell of the liquid heat exchanger and enters the top of the absorber coil at a reduced temperature.

The ammonia / water vapor passes through the rectifier whose reduced temperature causes any water vapour to liquefy and join the weak solution in the generator. The rich ammonia vapor enters the condenser and is changed to hot liquid ammonia. The liquid ammonia enters the tubular coil of the low and high temperature evaporators and wets the internal surface of the tubes. As the hydrogen passes over the wetted tube surface, the liquid ammonia evaporates into the hydrogen. During this process heat is extracted from the evaporator and therefore from the inside of the refrigerator.

The weight of the hydrogen and ammonia mixture is heavier than that of pure hydrogen. Consequently, it falls through the gas heat exchanger into the top of the leveling chamber. From this point it enters the bottom of the absorber coil. As the mixture travels up through the absorber it contacts the weak solution entering the top of the absorber from the generator. As the weak solution drops through the absorber it absorbs the ammonia from the ammonia / hydrogen mixture. The relatively pure hydrogen passes through the hydrogen circuit to the evaporator and now the rich solution falls to the bottom of the leveling chamber where the cycle starts again.