Basic Mechanisms of Noncondensable Gas Cryotrapping
This report has yet to be scanned by Contrails staff
Report Number: AEDC TDR 63-147
Corporate Author(s): General Technology Corporation
Date of Publication: 1963-07
Pages: 58
Contract: AF 40(600)-941
DoD Project: 6950
DoD Task: 695001
Identifier: AD0410735
Abstract:
Systematic measurements are reported on the rate at which argon and nitrogen are trapped by water as it condenses under vacuum onto a 77 K surface. For condensation rates between 10 to the 15th power and 10 to the 18th power molecules per sq. cm -sec. and noncondensable partial pressures between 0.000001 and 0.1 torr, trapping rates are proportional to condensation rate and a concen tration of adsorbed gas. The latter are described by Langmuir isotherms with characteristic pres sures for saturation of 0.0025 torr and 0.0035 torr for nitrogen and argon respectively. Inde pendent adsorption measurements show that quantity of gas adsorbed is proportional to mass of con densate (approximately 600 sq. meters per gram) and depends on pressure identically with the trap ping. Apparent trapping due to adsorption on surface area generated during condensation is only about 7% of actual trapping. All the results are consistent with a mixed phase for the con densate of which approximately 10% is the 12A gas hydrate.
Provenance: IIT
Corporate Author(s): General Technology Corporation
Date of Publication: 1963-07
Pages: 58
Contract: AF 40(600)-941
DoD Project: 6950
DoD Task: 695001
Identifier: AD0410735
Abstract:
Systematic measurements are reported on the rate at which argon and nitrogen are trapped by water as it condenses under vacuum onto a 77 K surface. For condensation rates between 10 to the 15th power and 10 to the 18th power molecules per sq. cm -sec. and noncondensable partial pressures between 0.000001 and 0.1 torr, trapping rates are proportional to condensation rate and a concen tration of adsorbed gas. The latter are described by Langmuir isotherms with characteristic pres sures for saturation of 0.0025 torr and 0.0035 torr for nitrogen and argon respectively. Inde pendent adsorption measurements show that quantity of gas adsorbed is proportional to mass of con densate (approximately 600 sq. meters per gram) and depends on pressure identically with the trap ping. Apparent trapping due to adsorption on surface area generated during condensation is only about 7% of actual trapping. All the results are consistent with a mixed phase for the con densate of which approximately 10% is the 12A gas hydrate.
Provenance: IIT