ALMiG Dessicant Air Dryers
The ALMiG AWDB Series of heat regenerative desiccant dryers is designed to guarantee ISO 8573.1 Class 2 (-40°F/-40°C) dew point performance. This series is designed for performance and can achieve the design dew point while operating continuously at maximum rated flow (100% duty cycle) at CAGI ADF 200 inlet standards of 100°F inlet temperature and 100% relative humidity at 100 psig. To improve air system efficiency, the AWDB series makes use of a dedicated axial blower to regenerate the off-line desiccant tower rather than a percentage of dehydrated purge air. Overall, blower purge type regenerative dryers achieve economical and reliable operation to dry compressed air below freezing.
The general operation of desiccant dryers involves adsorbing the water vapor present in the compressed air onto the surface of the desiccant. This will continue until equilibrium is reached between the partial pressure of the water vapor in the air and that on the surface of the desiccant. The compressed air is continuously processed by way of using two identical towers, each containing a desiccant bed. One tower is “on-stream” meaning that it is performing the act of drying. The other tower is “off-stream” meaning it is being dried out and prepared to be on-stream. These towers alternate between being on-stream and off-stream so that the wet compressed air is always brought into contact with a dry desiccant. This alternating mechanism is controlled by a solid-state controller on a fixed time basis (standard) or a demand basis (optional). This allows for a continuous supply of dry air down stream of the system.