Development Status of an EVA-sized Cycling Amine Bed System for Spacesuit Carbon Dioxide and Humidity Removal 2007-01-3272

Under a NASA sponsored technology development activity, Hamilton Sundstrand has designed, fabricated, tested and delivered a prototype solid amine-based carbon dioxide (CO₂) and water (H₂O) vapor removal system sized for Extravehicular Activity (EVA) operation. The prototype system employs two alternating and thermally-linked solid amine sorbent beds to continuously remove CO₂ and H₂O vapor from a closed environment. While one sorbent bed is exposed to the vent loop to remove CO₂ and water vapor, the other bed is exposed to a regeneration circuit, defined as either vacuum or an inert sweep gas stream. A linear spool valve, coupled directly to the amine canister assembly, is utilized to simultaneously divert the vent loop flow and regeneration circuit flow between the two sorbent beds. A variable cycle time concept was evaluated to self-optimize system operation according to the simulated metabolic challenge to investigate the performance for an anticipated metabolic load profile of a typical EVA mission. Concurrent H₂O vapor removal performance was also evaluated over a range of anticipated humidity conditions. This paper describes the current state of development for an EVA-sized cycling amine bed system and presents the results of laboratory testing of the prototype system.