Abstract: A control system for use with an adsorber unit, of particular use in controlling multi-unit adsorber systems, comprises means for detecting in exhaust from the adsorber, gas or vapour to be adsorbed in the parts per million range, and means for switching the adsorber units from which the exhaust issues from an adsorbtive to a regenerative mode when said gas or vapour is detected in the exhaust in an amount in excess of a predetermined level.

Abstract: An improved vessel design is provided for contact of gas or vapour with particulate solid material, for example for adsorption systems such as air drying and solvent recovery systems, in which a plurality of trays for containing the particulate material are supported by a pillar structure within the shell of the vessel, the shell serving merely as an envelope which does not provide support for the trays thereby enabling a considerable reduction in material costs for the shell and greater design flexibility for the site where the vessel is to be installed. The pillar preferably forms a manifold for conveying gas or vapour streams to or from each of the trays and deflecting baffles for the gas or vapour streams are also provided. A sparge pipe may also extend along the duct to introduce steam or other purge gas for regeneration of an adsorbent in situ.