Adsorbent fractionators with electronic sequence timer cycle control and

Abstract

A method and apparatus are provided for adsorbing one or more first gases from a mixture thereof with a second gas to reduce the concentration of first gas in the mixture to below a permissible maximum concentration by passing the mixture in contact with and from one end to another end of one of two beds of a sorbent having a preferential affinity for the first gas, adsorbing first gas thereon to form a gaseous effluent having a concentration thereof below the maximum, while passing a purge flow of gaseous effluent through the other of the two beds of sorbent to desorb first gas adsorbed thereon, regenerating the other bed for another cycle of adsorption; periodically interchanging the beds so that, alternately, one bed is on regeneration and the other on the adsorption portions of the cycle; timing the cycling in fixed timing intervals determined electronically by a combination of digital integrated circuitry including controlling cycling time at a period not shorter than the regeneration time; and switching the sorbent beds at the end of such cycling time. The system is particularly applicable to the drying of gases.