Abstract: A product stream of hot gas is formed at elevated pressure. A primary gas stream is passed at elevated pressure through a flow control valve in a primary gas stream inlet to a plasma generator. The plasma generator is operated so as to heat the primary gas stream. The heated primary gas stream passes into a gas mixing chamber. A secondary gas stream passes through a flow control valve into the gas mixing chamber. A product gas stream leaves the gas mixing chamber. The temperature of the product gas stream is sensed. One or both of the flow valves and/or the operating power of the plasma generator may be used or adjusted to control the temperature of the product gas stream.

Abstract: Apparatus is described for treating an effluent fluid stream from a semiconductor manufacturing process tool. The apparatus comprises a combustion chamber, means for heating the combustion chamber, and a nozzle for injecting the effluent stream into the combustion chamber. The apparatus is configured to enable a fuel and an oxidant to be selectively injected into the effluent stream as required to optimise the combustion conditions for a particular effluent stream. In one to embodiment, a lance projecting into the nozzle selectively injects an oxidant into the effluent stream, and a sleeve surrounding the nozzle selectively injects a fuel into the effluent stream.

Abstract: A seal assembly for the protection of a static seal device for use in a vacuum pump. The seal assembly comprising at least two components which are sealingly connected together, an o-ring seal, which is engaged between the two components to prevent transfer of fluid to and from the pump between these two components and a fluid channel. The fluid channel being in the plane of the o-ring and located between the o-ring seal and a process gas flow path. The fluid channel provides a path for a barrier gas to be routed when the apparatus is in use. The channel being connectable to an external source of barrier fluid and having an outlet in fluid communication with the pump swept volume.

Abstract: An article of titanium or a titanium-based alloy, or of zirconium or a zirconium-based alloy is case hardened by heat treatment for at least 12 hours at one or more temperatures in the range of 850° C. to 900° C. and at a pressure in the order of atmospheric pressure in an oxygen diffusion atmosphere. The oxygen diffusion atmosphere comprises a carrier gas such as argon which does not react chemically with the article the said temperature range and molecular oxygen. The concentration of oxygen as the oxygen diffusion atmosphere is in the range of 10 volumes per million to 400 volumes per million.

Abstract: In a pumping arrangement for a chamber, a regenerative pumping mechanism comprises a rotor and a stator having an annular channel within which rotor blades rotate to urge fluid along the channel. The channel has a stripper, a channel inlet positioned adjacent one end of the stripper and through which fluid from the chamber enters the channel, and a channel outlet positioned adjacent the other end of the stripper and through which pressurised fluid leaves the channel. The stator further comprises a fluid bypass in the form of a bore having an inlet and an outlet on either side of the stripper. A valve allows fluid entering the channel to selectively diverted through the bore to the channel outlet. This can allow the performance of the pump to be varied without changing the speed of rotation of the rotor, and thus allow the pressure in the chamber to be accurately controlled.

Abstract: A regenerative fluid pump (10) comprises a rotor having rotor blades for compressing fluid on two fluid flow paths, the first of which extends between a first pump inlet (12a) and a first pump outlet (14a), and a second of which extends between second pump inlet (12b) and a second pump outlet (14b). The pump comprises a stator comprising a plurality of concentric channels (16), each of which comprises: a pumping channel portion (18) along which said rotor blades move for compressing said fluid between an inlet and an outlet of the pumping channel; and a stripper channel portion (20) (shown in broken lines) which allows movement of said rotor blades from said outlet to said inlet of the pumping channel portion. Each concentric channel (16) comprises two pumping channel portions (18) and two stripper channel portions (20).

Abstract: A thermal conductivity type pressure gauge comprises a gauge head (2) being rotatably mountable in a vessel whose environmental pressure is to be measured and an elongate electrical filament (6) mounted in the gauge head, the gauge head (2) having an inlet where through the electrical filament is exposed to the environmental pressure within the vessel and the filament (6) having directional component lengths in two orthogonal axes, one of the orthogonal axes X—X being parallel to the axis of rotation of the gauge head (2).

Abstract: In a method of delivering high purity fluorine to a processing system, an on-site fluorine generator supplies high purity fluorine to a fixed storage tank, from which the high purity fluorine is supplied to the processing system. To provide a back up to the fluorine generator, high purity fluorine is also provided in a transportable gas storage vessel, for example, a multi-cylinder pack at a relatively low pressure, typically less than 35 psig. The transportable storage vessel is selectively connected to the fixed storage tank as required to enable the amount of fluorine within the storage tank to be maintained at a desired level.

Abstract: A hot object is quenched after heat treatment. A hot gas stream having at least 20% by volume of hydrogen is taken from for example a carburising chamber of a furnace. The gas is cooled by passage through a heat exchanger, and is compressed in a compressor. The compressor has an aftercooler (not shown) to remove heat of compression from the gas. The cooled, compressed gas flows through nozzles into a quenching chamber. The gas leaves the nozzles at a velocity of at least 50 m/s and impinges upon the hot metal object so as to effect its quenching.

Abstract: Apparatus for producing liquid or solid xenon comprises a duct 12 having an inlet 14 for receiving gaseous xenon and an outlet 16 for outputting gaseous xenon at a reduced temperature to a nozzle located in a vacuum chamber 60. A housing 18 extends about the duct and contains a halocarbon coolant in thermal contact with the duct, and a second duct 24 in thermal contact with the halocarbon coolant for conveying a flow of liquid nitrogen through the housing 18 to control the temperature of the halocarbon. In view of the difference in the pressure of the xenon gas output from the duct and the pressure in the chamber, the thus-cooled gas is caused to liquefy or solidify in the vicinity of the nozzle.

Abstract: Nitrogen is rejected from a pressurised feed gas stream comprising methane and nitrogen by cooling the feed gas stream in a main heat exchanger 10 and rectifying the cooled feed gas stream in a double rectification column 20 comprising a higher pressure rectification column 22, a lower pressure rectification column 24, and a condenser-reboiler 25 placing the higher pressure column 22 in heat exchange relationship with the lower pressure column 24. A pump 50 withdraws a methane product stream from the column 24. The methane product stream is pressurised by the pump 50 and is vaporised in the main heat exchanger 10. The pressurised feed gas stream is expanded with the performance of external work in an expansion turbine 6 upstream of the main heat exchanger 10.

Abstract: A vacuum pump system (10; 36; 46) for pumping gas from an enclosure (12) comprises: a vacuum pump unit (14) having a pump inlet (16) connectable with an outlet (18) of such an enclosure and a pump outlet (20) for exhausting gas; and a chamber (22; 50) selectively connectable with the pump inlet and the pump outlet, such that, in use, in a first state gas can be pumped from the chamber to the pump inlet by the vacuum pump unit and in a second state gas can be evacuated from the pump outlet to the chamber to reduce pressure at the pump outlet. A method of controlling the vacuum pump system (10; 36; 46) comprises a first step of pumping gas from the chamber to the pump inlet using the vacuum pump unit and a second step of allowing gas to be evacuated from the pump outlet to the chamber to reduce pressure at the pump outlet.

Abstract: A vacuum pumping system comprises a first gas supply for supplying a first gas, such as xenon, to a vacuum chamber. A pump receives the gas output from the chamber. A second gas supply supplies a purge gas, such as nitrogen or helium, for pumping with the first gas. A gas separator receives the pumped gases exhausted by the pump, and recovers the first gas and the purge gas from the stream. The recovered first gas is recirculated through the vacuum chamber, and the recovered second gas is recirculated through at least the pump.

Abstract: A freeze dryer comprising a chamber having a rectangular slot through which vials are inserted into the chamber, and a slot door for forming a seal with the chamber to close the slot. To enable the vials to be subsequently removed from the chamber, the slot door is raised. As the door is raised, it is rotated to expose the rear surface of the door for cleaning purposes.

Abstract: A method of working metal in which molten metal particles are ejected from, for example, a welding electrode or from a metal workpiece being cut or drilled. The ejected molten metal particles are caused to pass through a contact region in which they make contact with a cryogen, for example, liquid nitrogen or solid carbon dioxide. The contact renders the particles non-adherent to any adjacent surface to which the particles would otherwise adhere. Alternatively, the adjacent surface may be cooled by contact with a cryogen so as to render the particles non-adherent thereto.

Abstract: Nitrogen is rejected from a feed natural gas stream comprising methane and nitrogen so as to form a primary methane product. The mole fraction of nitrogen in the feed natural gas increases over a period of time. The feed natural gas stream is cooled in a main heat exchanger and is rectified in a double rectification column. A primary product methane stream and a secondary nitrogen-enriched product stream are withdrawn from the rectification column. The secondary nitrogen-enriched product stream has a mole fraction of methane at or above a chosen minimum value when the said mole fraction of nitrogen is at a minimum. When the said mole fraction of nitrogen rises to a value at which the mole fraction of methane in the secondary nitrogen-enriched product stream falls below the chosen minimum, a part of the feed gas is introduced through conduit into the secondary nitrogen-enriched product stream so as to restore its mole fraction of methane to the chosen minimum value or a value thereabove.

Abstract: A method of filling and sealing a gas capsule having (i) a hollow body portion and (ii) an elongate hollow neck portion having a free open distal end extending from the body portion is disclosed. The method is accomplished by applying a filling cap to the open end of the neck portion while evacuating the capsule and refilling with helium. Two crimping steps while pressure is maintained finishes the filling and sealing method.

Abstract: A method of assembling a scroll pump comprises the following steps carried out sequentially: the step of mounting a first bearing means (20) and drive shaft (14) for rotation relative to a housing (12): the step of fastening a first flange portion (48) of a bellows arrangement (34) relative to the housing (12); the step of fastening an orbiting scroll (26) to a second flange portion (56) of the bellows arrangement (34): and the step of fixing a second scroll (28) relative to the housing (12) for co-operation with the orbiting scroll (26). The second flange portion (56) is fastened to the orbiting scroll (26) with fasteners (60) which extend through a through-bore (61) in the orbiting scroll and engage with the second flange portion.

Abstract: A mechanical pump having an inlet and spaced therefrom an outlet for the passage of fluid therethrough and incorporating at least one flame arrester.

Abstract: A valve comprising a housing having an inlet and spaced therefrom an outlet, a passageway extending between the inlet and the outlet, and a mechanism located in the passageway for controlling the flow of a fluid between the inlet and the outlet, the mechanism including a valve assembly movable between a first open position spaced from a co-operating valve seat and a second closed position at which the valve assembly sealingly engages the valve seat, in which the valve assembly is biased towards the second closed position using a magnet-operated mechanism.