working principle for adsorption air dryers:
    the adsorption type compressed air dryer works by taking advantage of the porous characteristic to the desiccant . the moisture in the air absorbed by the desiccant through its capillary action and then the absorbed water is removed through desorption and temperature-raise by the residual heat generated during the adsorption process. In general , the dryer is in two cylinders and they continuously and alternatively work under program-control .When one cylinder absorbs moisture, the another one is regenerated through desorption of the desiccant.