Patent ID: 7279026
Filing Date: 2007-10-09
Classification: B01D

Abstract:
1. A heat of compression gas drying apparatus having a dryer inlet for receiving compressed moisture laden air, and a dryer outlet for delivering compressed dry air, the apparatus comprising: a first desiccant-containing tower having a first exhaust valve arrangement; a second desiccant-containing tower having a second exhaust valve arrangement; an aftercooler, separator and drain system; conduit structure for interconnecting the first and second towers with the aftercooler, separator and drain system, and enabling passage of the moisture laden air from the dryer inlet to be processed by the first and second towers and the aftercooler, separator and drain system for delivering cooled dry air to the dryer outlet; a control arrangement connected to the conduit structure for controlling the flow of air through the first and second towers and the aftercooler, separator and drain system, the control arrangement including a purge isolation valve; and a heater interconnected to the first and second towers by the conduit structure and selectively energized by the control arrangement to receive a portion of dry air from one of the towers in response to periodic actuation of the exhaust valve arrangement so as to periodically deliver heated dried air to the other of the towers with its exhaust valve arrangement closed, the control arrangement allowing de-energization of the heater and bypassing of the cooled dry air outside the de-energized heater through the conduit structure for periodically delivering cooled dried air to the other of the towers, whereby closing of the exhaust valve arrangement permits building of a predetermined pressure on the conduit structure, the heater and the other of the towers and momentary holding of the pressure in the other of the towers, for a predetermined interval after which the exhaust valve arrangement of the other of the towers is pulsed open to purge the dried air in the other of the towers to atmosphere.