Abstract: A method and apparatus are provided for adsorbing water vapor or other first gas from a mixture thereof with a second gas to reduce the water vapor or first gas concentration in the mixture to below a permissible maximum concentration, in which the advance of the leading edge of the adsorption front in a sorbent bed is detected by sensing the advance of the temperature front that precedes the adsorption front, and this advance is detected by sensing the temperature of the sorbent bed sufficiently far from the end of the bed to prevent the temperature front from leaving the bed, using a temperature sampling probe, when the temperature front reaches this point, the adsorption front is still a distance away, since it follows the temperature front, and the absorption cycle is discontinued, and the bed regenerated; the regeneration cycle can similarly be controlled independently, to be terminated when regeneration is complete, as detected by advance of the temperature front in the opposite direction.

Abstract: An electromagnetic detector device embodying a linear voltage differential transformer. A pair of coils of the differential transformer serve as pick-up coils connected in a detector circuit which is phase sensitive and capable of discriminating between signals representing a target metallic material, such as carbon steel particles trapped in a filter element, and signals induced by other metallic material, as well as stray signals including electrical noise. Input signals representing a target metallic material are fed to an operational amplifier circuit including a first non-inverting amplifier and a second inverting amplifier which produce a non-inverted signal and an inverted signal which are fed to an analog switch. The switch is operated as a chopper by a driver signal having a predetermined phase and the same frequency relative to the signal driving an input coil to the transformer. The phase of the driver signal is adjustable to provide phase discrimination.

Abstract: A sensing and indicator system for monitoring multiple electric heating elements connected in three-phase balanced Y circuits in heat reactivatable adsorbent gas fractionators. The system senses a failure induced imbalance, pinpoints the location of the group with the failure and causes a failure indicating alarm to function. The system operates by a sensing circuit including a discharge bulb sensing the failure induced imbalance and causing a conduction of current through the system resulting in the activation of an alarm and the illumination of the gas discharge bulb indicating which of multiple sets of heating elements has failed.

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