Moisture adsorption performance investigation on double layer multi-stage desiccant packed bed under different conditions

The development of new solid desiccant beds and further research on dehumidification performance are essential for enriching the structure forms of desiccant bed and promoting energy saving. A solid dehumidifier called double layer multi-stage desiccant bed (DL-MS-DB) is proposed in this research. The bed is mainly composed of two dehumidification units and five-stage dehumidification modules. The effect of different inlet air conditions, and material layer thickness on moisture adsorption performance of DL-MS-DB was investigated experimentally. Results reveal that moisture adsorption performance of DL-MS-DB is more sensitive to the inlet air humidity than the temperature. Higher inlet air velocity would lead to a reduction in transient dehumidification capacity. Material layer thickness has a significant impact on the dehumidification performance. Maximum dehumidification rate of DL-MS-DB could reach 5.22 kg/h. The temperature rise of desiccants under different conditions ranges from 15.8 °C to 24.4 °C. Under similar conditions, the dehumidification capacity of the DL-MS-DB is 23.8 % and 6.5 % higher than that of the double-stage dehumidification box and three-stage adsorption packed bed, respectively. Compared to conventional desiccant wheel and multilayer fixed-bed, the dehumidification capacity of DL-MS-DB increases by 63.5 % and 20.2 %, respectively in an initial period. DL-MS-DB could reveal superior dehumidification performance.