Abstract: In the temperature-gradient type multistage condenser, a first cooling step is carried out at an outer cooling cylinder storing a freezing mixture. The outer cooling cylinder has an opening at the upper portion thereof and is constructed of double walls having a predetermined space between the walls, a second cooling step is carried out at a vertical pipe disposed substantially coaxially in the outer cooling cylinder, and a third cooling step is carried out at an inner cooling cylinder through which the vertical pipe passes. The cooling capacity is gradually increased as cooling proceeds from the first cooling step, and becomes substantially highest at the third cooling step wherein solvent vapor becomes thin.

Abstract: The liquid cooled trap for effectively and efficiently collecting condensable vapor in a chemical vapor reaction system includes two stages. The first stage includes an entrance area to the trap that is purposely designed to be large in space and a very poor heat exchanger in order to avoid condensation and resulting solid deposits that could clog the entrance port to the trap. The second stage comprises a better heat exchanger to spread the condensation and deposits efficiently over a larger surface area and a longer flow path. The second stage is a very efficient heat exchanger to clean up and remove whatever small amount of the condensable vapor remains after the first stage of the trap. The second stage includes cooling coil tubes and cooling cones or fins to increase the overall efficiency of the trap be increasing the interior surfaces upon which the flowing condensable vapor can condense, while not significantly reducing the flow conductance of the trap.

Abstract: A low lying fog simulator including a liquid carbon dioxide source and a cooler to be used with a smoke generating machine. The liquid carbon dioxide is forced through an expansion valve to provide a cold carbon dioxide gas pocket through which the smoke passes prior to being dispersed into the ambient. When dispersed into the ambient the cold smoke/carbon dioxide mixture falls toward a level near the earth's surface simulating a low lying fog.

Abstract: Installation and method to regenerate cold traps loaded with the hydride and oxide of a metal, such as sodium, in its liquid state. A forced circulation of the orginal liquid metal of a tank (11) is created at a temperature sufficient to dissolve the solid deposits. The hydrogen and tritium ions are filtered and end up at a storage tank (42) where they are fixed, whereas the oxygen ions recombine so as to form a new oxide deposit in another trap (23) cooled to a temperature enabling only the oxide to be deposited. An application is for fast neutron nuclear reactors and fusion reactors.

Abstract: A method and system for mechanically removing mercury from natural gas are provided. A mercury trap is positioned at substantially the coldest point in the system before a main heat exhanger. The trap includes a bend in the natural gas flow path, baffles, a demister and/or a perforated cylinder for changing the direction of the flow path and causing mercury to be deposited therein.

Abstract: A drip trap for separating a liquid from a gas includes a casing, an inlet duct near the top end of the casing for introducing a liquid-containing gas into the casing, a downspout on the inner end of the casing beneath the bottom end of the downspout for discharging liquid from the casing, and a four-way two port valve for connecting either the inlet duct to a gas line for receiving liquid-containing gas, or the outlet duct to a drain for discharging liquid from the casing. The liquid-containing gas is fed into the casing until the liquid rises above the bottom of the downspout to compress gas in the top end of the casing. The valve is rotated to close the inlet duct and open the outlet duct to the drain, whereby liquid is discharged from the casing. The trapped gas provides the driving pressure for discharging the liquid and positive prevention of continuous venting of manifold gas vapors through the trap to atmosphere.

Abstract: A cold trap for collecting components of an aerosol stream comprises an elongated vessel provided with an aerosol stream inlet and an aerosol stream outlet, a cooling jacket for subjecting a substantial portion of the walls of the vessel to temperatures below 0.degree. C. and a baffle assembly that includes a plurality of spaced baffle plates which cooperate to present a tortuous path to the flow of the aerosol stream as it moves through the vessel.

Abstract: A fume hood with an air actuated valve system for directing a mixture of room and external air in front of a horizontal sash when such sash is open, and behind this sash when it is closed.

Abstract: A laboratory fume hood that has a lower baffle, intermediate baffle, and upper baffle spaced from each other and from a floor of the fume hood for directing fumes upwardly to an exhaust opening. The baffle system provides an inverted funnel configuration with the hood wall for improved gas sweeping action adjacent the hood floor.

Abstract: Cryopumping speed of nitrogen, helium, hydrogen and neon can be increased by omitting the chevron baffle in a conventional cryopump and preventing incident radiation of about 300.degree. K. from striking surfaces used to cryosorb helium, hydrogen and neon. An apparatus is disclosed utilizing three pumping surfaces created from open ended opposed nested cylinders. A radiation absorbent coating is placed on one of the surfaces to shield the helium, hydrogen and neon pumping surface. Refrigeration can be provided by a two-stage closed cycle cryogenic refrigerator.

Abstract: A multiple stage cryogenic vacuum pump is disclosed for transferring matter or species between a gas and a vacuum chamber. The vacuum chamber has an orifice through which the matter or species moves and through which some of the gas leaks into the chamber. The chamber also has an interior surface which is spaced from the path of movement of the matter or species and encircles such path, and an internal divider extending to a position adjacent the interior surface and dividing the chamber into a first region adjacent the orifice and a second region downstream from the first region, with the interior surface extending in both regions. The surface is cooled by a single refrigerating device to below the condensation temperature of the gas, to produce a pressure below atmospheric in the first region and a lower pressure in the second region. The divider contains an aperture through which the matter or species travels and may itself be cooled to precool gas contacting it.

Abstract: A ball valve for use in a vacuum pumping system has the passage through the valve element provided with a series of metal plates disposed for contact by gas passing through the valve when open. A refrigerant conduit entering the passage through the neck of the valve element by which it is turned between open and closed positions includes a U-shaped portion within the passage with which the plates are in thermal contact and the conduit then exits through the neck. The valve casing has sealed clean-out ports through which the passage is accessible when the valve is closed thus permitting the thus established cold trap to be serviced without losing vacuum in the chamber being exhausted, the valve monitored, and the passage rough-pumped.

Abstract: The invention relates to a regeneration-type cryopump which has an annular reservoir for liquid nitrogen situated above an annular reservoir for liquid helium and incorporates, sliding in the central opening in the said reservoir, a valve member which is mounted on a rod. When the valve member is in one position, the cryopump is in normal operation, whereas when the valve member is in another position and rests against a seating, regeneration may take place.Such a pump may be used for generating very high vacua.