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Wire-Mesh-Based Sorber for Removing Contaminants From Air

A paper discusses an experimental regenerable sorber for removing CO2 and trace components — principally, volatile organic compounds, halocarbons, and NH3 — from spacecraft cabin air. This regenerable sorber is a prototype of what is intended to be a lightweight alternative to activated-carbon and zeolite- pellet sorbent beds now in use. The regenerable sorber consists mainly of an assembly of commercially available meshes that have been coated with a specially formulated washcoat containing zeolites. The zeolites act as the sorbents while the meshes support the zeolite-containing washcoat in a configuration that affords highly effective surface area for exposing the sorbents to flowing air. The meshes also define flow paths characterized by short channel lengths to prevent excessive buildup of flow boundary layers. Flow boundary layer resistance is undesired because it can impede mass and heat transfer. The total weight and volume comparison versus the atmosphere revitalization equipment used onboard the International Space Station for CO2 and trace-component removal will depend upon the design details of the final embodiment. However, the integrated mesh-based CO2 and trace-contaminant removal system is expected to provide overall weight and volume savings by eliminating most of the trace-contaminant control equipment presently used in parallel processing schemes traditionally used for spacecraft. The mesh-based sorbent media enables integrating the two processes within a compact package. For the purpose of regeneration, the sorber can be heated by passing electric currents through the metallic meshes combined with exposure to space vacuum. The minimal thermal mass of the meshes offers the potential for reduced regeneration- power requirements and cycle time required for regeneration compared to regenerable sorption processes now in use.

This work was done by Jay Perry of Marshall Space Flight Center, and Subir Roychoudhury and Dennis Walsh of Precision Combustion, Inc.

In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to: Precision Combustion, Inc. 410 Sackett Point Road North Haven, CT 06473-3106 Phone No.: (203) 287-3700 Fax No.: (203) 287-3710 Refer to MFS-32308-1, volume and number of this NASA Tech Briefs issue, and the page number.