The adsorption dryer is through the "pressure change" (pressure change adsorption principle) to achieve the drying effect. Because the ability of the air to hold water vapor is inversely proportional to the pressure, the dry part of the air (called regas), pressure expansion to atmospheric pressure, the expansion air more dry, and then let it through the unconnected air regeneration desiccant layer (which has absorbed enough water drying tower), the dry water in the desiccant, take it out of the dryer to achieve the purpose of dewetting.