Accession Number : AD0439850

Title :   THE CRYOSORPTION PUMPING OF HYDROGEN AT 20 K,

Corporate Author : UNION CARBIDE CORP TONAWANDA N Y LINDE DIV

Personal Author(s) : Hemstreet,R. A. ; Robb,Q. G. ; Pitlor,J. R. ; Potts,L. D. ; Ruttenbur,D. M.

Report Date : MAY 1964

Pagination or Media Count : 101

Abstract : An experimental and theoretical study of the pumping of hydrogen by adsorbents cooled at 20 K is presented. The study covers the pressure range of 10 to the minus 9 to 10 to the minus 5 torr. The adsorbents studied were charcoal, Molecular Sieves 4A, 5A, 10X, 13X, and several special Molecular Sieves containing aluminum flake. Molecular Sieve 5A was selected as the preferred adsorbent for hydrogen cryosorption pumping. Incorporation of aluminum flake into the Molecular Sieve increased its thermal conductivity and reduced its optical emissivity. Techniques were developed for bonding Molecular Sieves to metal surfaces to form cryosorption panels. A hydrogen adsorption coefficient of 0.16 was measured for a Molecular Sieve 5A surface bonded to aluminum. This coefficient corresponds to an unbaffled pumping speed of 6600 liters/sec sq ft of adsorbent. The adsorption coefficient was relatively insensitive to the volume of adsorbed hydrogen as long as the volume was less than 1.5 cc (STP)/gm of adsorbent. Small volumes of condensable gases (nitrogen) on the adsorbent surface caused a marked decrease in the hydrogen adsorption coefficient. (Author)

Descriptors :   (*CRYOPUMPING, HYDROGEN), ADSORPTION, CHARCOAL, BONDING, ALUMINUM, COSTS, ECONOMICS, DENSITY, MONTE CARLO METHOD

Distribution Statement : APPROVED FOR PUBLIC RELEASE