Abstract: A vertical shaft furnace for melting scrap metal, particularly copper scrap, uses one or more burners operated superstoichiometrically in order to provide excess oxygen to react with a waste gas stream passing up through the copper scrap thereby reducing the amount of carbon dioxide and visual contaminants in the waste gas stream.

Abstract: A vacuum pump comprising a pump chamber having an inlet and an outlet and through which gas from an enclosure connectable to the inlet can be pumped to a pump exhaust. At least one rotor, adapted for high velocity rotation, is provided within the chamber and mounted on a shaft extending from the chamber and to a pump gearbox substantially isolated from the chamber by means of a shaft seal associated with the shaft. The shaft seal is of a close tolerance but non-contact design. During use of the pump, gas pressure in the vicinity of the shaft seals and arising from the changeable gas pressures associated with operation of the pump rotor is buffered.

Abstract: Liquid in which oxygen-containing gas is to be dissolved is pumped through a main and distributed into faster-moving subsidiary streams. Each subsidiary stream passes through a turbulence-inducing means and air or oxygen is introduced into the turbulent region of alternate streams. The relative proportions of air to oxygen introduction are varied so as economically and efficiently to oxygenate the liquid. The gas-containing liquid passes through nozzles back into the volume of the liquid at sufficient velocity to cause further turbulence, making gas bubbles shear into smaller bubbles and also agitating the body of liquid.

Abstract: In cooler used for coating a product such as food with a uniform layer of a liquid coating material, the mass of the product is measured either in the cooling chamber or just before it is introduced into the cooling chamber; the mass of a liquid cryogen which will suffice, when introduced into the cooling chamber and into contact with the product, to reduce the temperature of the mass of product to a first predetermined temperature below the melting point temperature of the coating material is calculated; the introduction of the calculated mass of liquid cryogen into the cooling chamber is controlled and the product is thereby cooled to the first predetermined temperature prior to application of a predetermined mass of coating material onto the cooled product to provide a coating thereon.

Abstract: Air is separated in a main rectification column comprising a higher pressure column, a lower pressure column and a condenser-reboiler replacing the higher pressure column in heat exchange relationship with the lower pressure column. A first liquid oxygen fraction concentrated in krypton and xenon is formed at the bottom of the lower pressure column and is withdrawn through outlet. Argon-oxygen separation takes place in the column and a vaporous argon-oxygen stream depleted of krypton and xenon is taken from the outlet as it is subjected to further rectification in a column, a second liquid oxygen fraction containing argon impurity being obtained. A stream of the second liquid oxygen fraction is withdrawn from the column through the outlet and is purified in the column so as to obtain a purified oxygen product.

Abstract: A screw pump provided with a first shaft and spaced therefrom and parallel thereto a second shaft mounted in a pump body. A first rotor is mounted on the first shaft and a second rotor mounted on the second shaft. Each of the first and second rotors having formed on an outer surface thereof one or more one helical vanes or threads intermeshing together so that rotary movement of the shafts will cause a fluid to be pumped. A first bearing arrangement is associated with the first shaft and a second bearing arrangement is associated with the second shaft. A bearing carrier is provided for each bearing arrangement and mounted within the pump body so as to be independent from each other.

Abstract: A spirit chilling apparatus comprising a drink chilling tube (4) concentric within an insulated container (6) filled with a constant boiling cryogen (8), such as acetone and solid carbon dioxide or similar azeotropic mixture. The innertube (4) is held in relatively poor thermal contact with the vessel (6) containing the liquid so that over a period of time it will adopt the temperature of the liquid (8) but when a measure of spirit is poured through it the specific heat of the tube (4) will be sufficient to result in a net temperature of −5° C. for both the spirit and the tube (4), the heat flow from the surrounding vessel (6) being insufficient to materially affect this. If the tube (4) is left in place it will again cool to the previous temperature so that a further measure of spirit can be cooled.

Abstract: A vacuum pumping system for use with a process chamber. The pumping system has a first vacuum pump whose inlet is adapted for communication via a first line with a chamber outlet and a second vacuum pump whose inlet is adapted for communication via a second line with a first pump outlet. A third line containing a throttle valve is linked to the first and to the second lines in parallel to the first vacuum pump to enable variable amounts of gas to flow through the throttle valve from the second line to the first line depending on the position of the throttle valve.

Abstract: A vacuum pump incorporating a screw mechanism section and comprising two externally threaded rotors mounted on respective shafts in a pump body. The externally threaded rotors are adapted for counter-rotation in a first chamber within the pump body with intermeshing of the rotor threads in order to pump gas from a pump inlet by action of the rotors. The root diameter of each rotor increases and the thread diameter of each rotor decreases in a direction from pump inlet and in which the gas is pumped. The two externally threaded rotors are positioned in the pump body by means of shaft bearings located inside cavities in the rotors. The cavities are sealed at the ends closest to the pump inlet.

Abstract: There is provided an air separation apparatus comprising, in fluid flow communication, a compressor having at least two stages in senes, a first outlet from a stage upstream of the final stage, an air purifier in fluid flow communication with the outlet and producing purified air in two parallel flow paths. One of the flow paths is in fluid flow communication, through a heat exchanger, to a rectification column that produces a purified nitrogen product. The second flow path in fluid flow communication with an inlet of the compressor downstream of the chosen stage and provides a purified air product via the compressor through a second outlet thereof also downstream of the chosen stage.

Abstract: Air is separated by rectification. The air is compressed in a main air compressor to a first pressure. Without further compression a first flow of the compressed air is cooled in a main heat exchanger to a temperature suitable for its separation by rectification. The first flow is introduced into the higher pressure column of a double rectification column comprising, in addition to the higher pressure column, a lower pressure column, in which a bottom oxygen fraction containing from about 50 to about 96 mole percent of oxygen is formed. A condenser-reboiler places the higher pressure column in heat exchange relationship with the lower pressure rectification column. A second flow of the compressed air is expanded with the performance of external work in an expansion turbine without further compression of the second flow upstream of the expansion. The expanded second flow is introduced into the lower pressure rectification column. An impure oxygen product is taken from the said bottom fraction.

Abstract: A cryogenic rotary pump for pressurizing a flow of a cryogenic liquid and for dividing the flow into a first lower pressure and a second higher pressure stream has a series of pumping chambers. A single rotary drive shaft carries a rotary inducer located in the chamber, a first impeller in the chamber, and a second impeller in the chamber. A liquid receiving chamber is located intermediate the pumping chambers. A first outlet from the pump for the first lower pressure stream is contiguous to the chamber and a second outlet is provided for the second higher pressure stream. The pump may serve to pressurize a flow of unboiled liquid oxygen from a sump of a lower pressure column of a double column also having a higher pressure column.

Abstract: An air separation plant has a product nitrogen compressor arranged to be driven by a steam turbine adapted to be operated in a cycle in which steam is able to be raised in a steam generator by heat exchange of water with hot gaseous exhaust from a gas turbine.

Abstract: A probe for analyzing furnace waste gas comprising a water-cooled outer tube containing an inner tube which is not water-cooled and which has a filter at its end. One end of the outer tube is sealed.

Abstract: Air is separated in a double rectification column comprising a higher pressure rectification column, a lower pressure rectification column, and a first condenser-reboiler, of which the condensing passages communicate with an upper region of the higher pressure rectification column, and the reboiling passage communicate with a lower region of the lower pressure rectification column. A second condenser-reboiler is operated so as to reboil a liquid fraction obtained in the higher pressure rectification column. A stream of the air to be separated is partially or totally condensed by indirect heat exchange with a stream of nitrogen condensed in the first condenser-reboiler. At least part of the stream of condensed nitrogen is taken as product downstream of its heat exchange with the second stream of compressed air.

Abstract: A vacuum pump comprising at least a molecular drag section and a turbo-molecular section, a rotor common to both sections and a stator common to both sections. The turbo-molecular section is positioned wholly within an envelope defined by the molecular drag section.

Abstract: Methods and apparatus for filling containers with a gas or gas mixture under pressure are disclosed. The apparatus comprises a fixed volume vessel for containing the gas at a pressure P.sub.1, a line extending from the fixed volume vessel to a buffer volume vessel which has a capacity greater than the volume of the container to be filled, a pressure controller for controlling the pressure of the gas in the line so that the gas reaches the buffer volume vessel at a pressure P.sub.2 which is less than P.sub.1, a further line extending from the buffer volume vessel to at least one filling nozzle, and a valve located in the further line for controlling the flow of gas from the buffer volume vessel to the gas capsule to be filled.

Abstract: A compound vacuum pump incorporating a screw mechanism section. The screw mechanism section comprising two externally threaded rotors mounted on respective shafts in a pump body. The rotors are adapted for counter-rotation in a first chamber within the pump body with intermeshing of the rotor threads to pump gas by action of the rotors. The root diameter of each rotor increases and the thread diameter of each rotor decreases in a direction taken from pump inlet and in which the gas is pumped. The pump additionally incorporates a roots mechanism section comprising two roots-type profile rotors also mounted on the respective shafts and adapted for counter-rotation in a second chamber within the pump body situated at an inlet end of the pump.

Abstract: The present invention provides an apparatus for cooling and/or gassifying a liquid 12 stored in a container 10 having an outlet 10b. The apparatus comprises an adsorbent 14 for receiving and adsorbing under pressure a quantity of gas and a three position cap 16. In a first position, said cap 16 simply acts to seal the contents within the container whilst in a second position it acts to cause release of adsorbed gas from adsorbent 14 which then passes through the beverage 12 thereby gassifying and/or cooling said beverage. A third position of the cap 16 allows for its removal from container 10 such that the beverage may be dispensed. The container may be provided with a thermochromatic coating to indicate when the liquid is at a predetermined temperature.

Abstract: A turbo-molecular vacuum pump comprising alternate first and second stages. The first stage comprises a plurality of blades arranged in an annular envelope with the blades depending radially from a disc and being angled about radial lines out of the plane of the disc. The second stage comprises a plurality of coaxial, concentric frusto-conical members arrayed in a plane parallel to that of the annular envelope such that at least some of the blades and at least some of the frusto-conical members are axially aligned and are adapted to remain so during rotation of one stage relative to the other.