Abstract: A method and apparatus for delivering a cryogen in which a cryogen is stored and delivered in a cryogenic storage facility having three tanks. Each of the tanks is filled with the cryogen in a subcooled liquid state to wash contaminants down toward a bottom region thereof. Thereafter, a minor stream composed of superheated vapor is introduced into the bottom region of each tank to pressurize each tank. A major stream of the superheated vapor is then introduced into each tank to form scrubbed cryogenic vapor in the head space region thereof which is used in forming the product stream. Each tank is subsequently used to dispense the cryogen to a vaporizer to form the superheated vapor which is in turn divided into the major and subsidiary streams.

Abstract: The present invention provides a method for cleaning articles by removing surface particulate matter from the articles. In accordance with the present invention, the articles are immersed in a bath of liquid cryogen, chemically non-reactive with the articles to be cleaned. Prior to immersion it is necessary to insure that the articles have a sufficiently high temperature above that of the liquid cryogen and during immersion it is also necessary to insure that the articles are immersed at a sufficient rate to insure that the liquid cryogen undergoes film boiling before undergoing nucleate boiling at the surfaces of the articles. The articles are left immersed so that nucleate boiling of the liquid cryogen occurs at the surfaces of the articles. During the nucleate boiling, the surface particulate matter is carried from the articles and into the liquid cryogen bath. After the articles have reached thermal equilibrium with the liquid cryogen, the articles are removed from the bath.

Abstract: The present invention provides a cryogenic storage container having a pressure vessel surrounded by a vacuum vessel for maintaining a vacuum between the outer wall of the vacuum vessel and the pressure vessel. A pair of intermediate and sub-intermediate heat shields are disposed between the outer wall of the vacuum vessel and the pressure vessel for intercepting the heat that would otherwise be transferred from the vacuum vessel to the pressure vessel. The heat intercepted by the intermediate heat shield is absorbed by liquid nitrogen contained within a liquid nitrogen container. The heat intercepted by the sub-intermediate heat shield is preferably absorbed by liquid neon in a liquid neon storage tank. The liquid nitrogen and neon absorb heat by undergoing a phase change, from liquid to vapor. In order to prevent failure of the liquid nitrogen container, the nitrogen is vented to the atmosphere over a period of time.

Abstract: A method and apparatus is disclosed in the separation of a gaseous mixture by pressure swing adsorption utilizing two beds of adsorptive material which are operated out of phase in the cycle thereby providing a more-or-less continuous flow of product. Each adsorbent bed contains a heat exchange chamber holding a volatile liquid. The liquid gives up vapor in the bed undergoing adsorption and condenses in the bed undergoing desorption. Heat is thereby transferred between the beds, thus improving the efficiency of each stage by retaining heat which would otherwise be lost.

Abstract: Apparatus for removing small particles from a substrate comprising a source of fluid carbon dioxide, a first means for expanding a portion of the fluid carbon dioxide into a first mixture containing gaseous carbon dioxide and fine droplets of liquid carbon dioxide, coalescing means for converting the first mixture into a second mixture containing gaseous carbon dioxide and larger liquid droplets of carbon dioxide, second expansion means for converting said second mixture into a third mixture containing solid particles of carbon dioxide and gaseous carbon dioxide, and means for directing said third mixture toward the substrate. Also disclosed are methods for removing fine particles from substrates utilizing the subject apparatus.

Abstract: There is disclosed a one-step process for purifying an inert gas achieved by contacting the inert gas including minute quantities of an impurity selected from the group consisting of CO, CO.sub.2, O.sub.2, H.sub.2, H.sub.2 O and mixtures thereof with a particulate material comprised of nickel in an amount of at least about 5% by weight as elemental nickel distributed over an effective area of surface, typically from about 100 to 200 m.sup.2 /g, thereby forming an inert gas having less than 1 ppm and preferably less than 0.1 ppm of any such impurity.

Abstract: An inert gas stream containing parts per million levels of impurities such as O.sub.2, CO, CO.sub.2, H.sub.2, H.sub.2 O, is purified by passing the same sequentially through a first bed and second bed of material. In the first bed, carbon monoxide and hydrogen are both reacted with oxygen to form CO.sub.2 and H.sub.2 O. The latter is retained in this first bed while the reaction products and the inert gas stream are supplied to a second of material which is comprised of a getter. In this bed, oxygen reacts with the getter material and carbon dioxide is adsorbed therein so that the inert gas stream leaving the second bed is substantially free of such impurities. The first and second beds of material operate at temperatures up to about 38.degree. and these materials may be regenerated by heating the same to approximately 200.degree. C. and purging such beds with a purge gas flow.

Abstract: Method and apparatus for separating gases having different partial pressures at a given temperature includes introducing a multi-component gas mixture into a chamber, reducing the temperature therein to solidify and liquefy all components. At least one component remains liquid which is evaporated, thereby separating such component from the solidified components which may then be liquefied and recovered. The process is especially useful in recovering radioactive krypton and xenon from the off gas streams of nuclear processes such as nuclear fuel reprocessing.