Performance of a Multipass Honeycomb Adsorber Regenerated by a Direct Hot Water Heating

Abstract

A multi-pass honeycomb rotary adsorber has been proposed to achieve a low temperature heat driven desiccant cooling process. This multi-pass honeycomb rotary adsorber has a sandwich arrangement of honeycomb shaped adsorbent blocks and aluminum passages. In the regeneration step, hot water flows in the passages heating the honeycomb adsorbent. Simultaneously, outside air is co-currently supplied to the adsorbent layer to discharge the desorbed water vapor. On the other hand, adsorption heat caused in the adsorption step can be removed by cool air which is counter-currently passing through inside of the passages to keep the sufficient adsorption capacity/rate. The vaporization heat of water remaining in the passages also accelerates the cooling of the adsorbent rotor. Dehumidifying performance of the above mentioned adsorber has been investigated under various operating conditions, which are air velocity of each sector, temperature of hot water and so on. It was confirmed that the adsorber could be regenerated by direct hot water heating and removal of adsorption heat generated in the adsorption step achieved the semi-isothermal dehumidification. It was also found that lower temperature heat around 50∘C was still effective in regeneration of the adsorbent rotor although the same temperature air was needed to discharge the desorbed water vapor. At the moment, detailed investigations including the influence of heat transfer between honeycomb rotor and aluminum passage are being carried out to improve the dehumidifying performance.