Timothy A. Nalette

Development Status of Regenerable Solid Amine CO 2 Control Systems

The development history of solid amine/water desorbed (SAWD) CO2 control systems is reviewed. The design of the preprototype SAWD I CO2 system on the basis of a three-man metabolic load at the 3.8 mm Hg ambient CO2 level, and the functions of the CO2 removal, CO2 storage/delivery, controller, and life test laboratory support packages are described. The development of a full-scale multiple canister SAWD II preprototype system, which is capable of conducting the CO2 removal/concentration function in a closed-loop atmosphere revitalization system during zero-gravity operation, is examined. The operation of the SAWD II system, including the absorption and desorption cycles, is analyzed. A reduction in the thermal mass of the canister and the systems energy transfer technique result in efficient energy use. The polyether foam, nylon felt, nickel foam, spring retained, and metal bellows bed tests performed to determine the design of the zero-gravity canister are studied; metal bellows are selected for the canisters configuration.

Development of a Regenerate Humidity and CO 2 Control System for an Advanced EMU

A five hour regenerable, nonventing Humidity and CO/sub 2/ Control Subsystem (HCCS) technology demonstration unit is being developed for potential use in an Advanced Extravehicular Mobility Unit (AEMU) for Space Station application. The HCCS incorporates a weak base anion exchange resin packed in a metal foam matrix heat exchanger. This system simultaneously removes CO/sub 2/ and water vapor with the resulting exothermic heat of reaction rejected to the heat exchanger. The system has no moving parts resulting in a highly reliable, simple configuration. Regeneration may be accomplished via internal heating and vacuum.

Development of an Advanced Solid Amine Humidity and CO 2 Control System for Potential Space Station Extravehicular Activity Application

A system for removing metabolic carbon dioxide and water vapor from breathing air within a space suit during NASA Space Station EVA is discussed. The solid amine compound used is packed within a water-cooled metal foam matrix heat-exchanger to remove the exothermic heat of chemical reaction. Details of the design of a canister for humidity and carbon dioxide control and performance of the system are presented.

Development of a Regenerable Metal Oxide Sheet Matrix CO2 Removal System

NASA-Johnson has guided the development of a nonventing Metal Oxide Regenerable EMU CO2 Removal Subsystem (MORES) which employs a catalyzed, Ag-based metal oxide to achieve CO2 removal during EVA, while requiring no supplemental cooling. Regeneration is then easily obtained by means of cabin air, in a simple hot-air process. The MORES technology has been demonstrated in the case of a full size EMU contaminant control cartridge employing a conventional packed bed, as well as an improved sheet matrix configuration.