The amine swingbed was in development for incorporation into Orion’s environmental control and life support system to remove metabolic carbon dioxide and humidity from the crew atmosphere. The compact, low-power swingbed uses space vacuum to regenerate itself. Direction was given by NASA to develop it for a payload experiment on ISS using the most recent engineering development laboratory unit. To minimize overboard humidity and crew cabin ullage losses, a method for removing humidity upstream of the amine swingbed had to be developed, along with a means to minimize overboard ullage losses when the swingbed cycled.

The amine swingbed removes carbon dioxide by flowing cabin air through a bed of amine sorbent beads.
To minimize humidity losses, a novel water save desiccant wheel was developed and built. Wet cabin air is passed over a rotating desiccant wheel upstream of the swingbed to remove humidity from incoming air. Downstream of the swingbed, dry air is heated and passed over the rotating desiccant wheel, and humidity is re-adsorbed into the process stream and sent back to the cabin. The single, regenerable desiccant wheel is in constant motion, adsorbing and desorbing humidity as it rotates through the continuously flowing process air.

To reduce swingbed ullage losses to space vacuum during the regeneration cycle, a slight modification was made to the swingbed valve manifold so that a percentage of the ullage air could be evacuated from the bed just prior to exposure to space vacuum.

This work was done by Matt Cates of TDA Research; Ed Hodgson of Hamilton Sundstrand; Lori (Shannon) Motes and Richard McMahon of MEI; Manuel Maurido, Charles Sager, and Bruce Conger of Jacobs Technology; and Adrian Ramos of GeoComrol Systems for Johnson Space Center. For further information, contact the JSC Technology Transfer Office at (281) 483-3809. MSC-25290-1