Abstract: An anesthetic vaporizer 1 for use particularly with anesthetic agents having a low boiling point comprises an inlet 2 for carrier gas an an outlet 4 for carrier gas and gaseous anesthetic agents. A first passage 6 extends between the inlet 2 and the outlet 4. A flow restrictor 8 is located within the passage 6. A second passage 10 extends between the first passage 6 at a location upstream of the flow restrictor 8 and a regulator 14. The regulator 14 controls the pressure of gaseous anesthetic agent when flowing through a third passage 26 extending from a vaporizing chamber 12 containing anesthetic agent to the first passage 6 at a location downstream of the flow restrictor 8. A flow control valve 28 is located in the third passage 26.

Abstract: The present invention provides a sealing arrangement for effecting a seal with a rotatable shaft having with respect to its longitudinal axis a generally cylindrical shape but with a portion thereof of conical shape, which comprises a shaft seal positioned so that its sealing lip engages the shaft and so that any liquid escaping from a first (liquid) side of the seal to a second (air) side of the seal enters an annular cavity formed on one side by the conical portion of the shaft whose cross-sectional diameter decreases in a direction away from the sealing lip on the second side.

Abstract: A membrane gas separation apparatus, typically for separating air, includes a gas separation cell containing an array of membranes in the form of hollow fibres. The cell has a first gas port and a second gas port. Flow of gas to and from the ports is controlled by a four-port, two-position valve. In one position, the valve admits incoming air to the first port and allows product nitrogen to flow out of the second port. In the other position the roles of the ports are reversed and hence the direction of flow of the gas is reversed. During prolonged operation, there is a tendency for contaminants to affect disproportionately the feed gas inlet of the membrane fibres. By periodically changing the position of the valve, different ends of the membrane fibres are presented to the feed gas, and thus the operating life of the membranes is lengthened.

Abstract: A compressed air stream is separated in a double rectification column having a higher pressure stage and a lower pressure stage. The lower pressure stage contains a low pressure drop liquid-vapor contact means having a pressure drop of less than about 400.0 Pa per theoretical stage, for example a structured packing, to effect mass transfer between ascending vapor and descending liquid. A product gaseous oxygen stream is withdrawn from the lower pressure stage through an outlet thereof and is warmed to about ambient temperature in a heat exchanger in countercurrent flow relationship with the compressed air stream which is thereby cooled. Refrigeration for the process is created by expansion of part of the incoming air.

Abstract: A gas treatment or separation apparatus includes a vessel (2) containing a bed (18) of particulate material. Within the bed (18) there is located a plurality of distensible hollow members (30) each capable of being placed in communication with a source of fluid under pressure. The members (30) restrain movement of the particulate material.

Abstract: A process for separation of a gas mixture containing three components, e.g. a mixture comprising hydrogen, carbon monoxide and carbon dioxide produced by steam reforming a hydrocarbon, by pressure swing adsorption is disclosed.

Abstract: In order to provide `ultra high purity` nitrogen having diminished concentrations of light and heavy impurities in comparison with nitrogen produced by conventional cryogenic air separation, the nitrogen product from a conventional cryogenic air separation column is introduced into the bottom of a liquid-vapor contract column 2 fitted with a condenser 8 to provide reflux. A liquid nitrogen stream having a reduced concentration of heavy impurities is withdrawn from the column 2 through an outlet 22 situated at a level a few trays below the top tray in the column 2. The liquid nitrogen is then subjected to two stages of flash separation. In the first stage the liquid is passed through valve 24 into a phase separator 26. In the second stage, the resulting liquid from the first stage, having a reduced concentration of light impurities, is passed through valve 32 into a phase separator 34. Liquid nitrogen product is withdrawn from the phase separator 34 through outlet 38.

Abstract: A liquid-gas contact device comprising a liquid-gas contact tray comprising a multiplicity of the elongate apertures in the tray for the passage of gas from below to above the tray, each aperture having a gas deflector associated therewith in being so disposed as to impart to the gas a component of velocity in the general direction of liquid flow, and at least several liquid flow in impedance members arranged so as to control the liquid velocity on the liquid-bearing surface to prevent it from reaching so great a magnitude that the residence time of liquid on the tray is insufficient for adequate gas-liquid contact to take place. Preferably the tray comprises a sheet of expanded metal.

Abstract: Compressed air is purified in apparatus 4 and passed through heat exchanger 6 in which it is reduced in temperature ready for rectification in a double column comprising a higher pressure rectification column 10 and a lower pressure rectification column 12 which are linked by a condenser-reboiler 14. The air is separated in the column 10 into oxygen-rich and nitrogen fractions. The oxygen-rich fraction is separated in the lower pressure column 12 into an oxygen and a lower pressure nitrogen product. Liquid nitrogen from the higher pressure column 10 is used as reflux in the lower pressure column 12, and a gaseous nitrogen stream is withdrawn from the column 10 as higher pressure nitrogen product. In order to compensate for the resulting loss of reflux in the column 12, a part of the lower pressure nitrogen product stream is compressed in compressor 38, cooled by passage through heat exchanger 6, and condensed in condenser 40. The resulting condensate provides additional reflux in the column 12.

Abstract: A method and apparatus for recovering work from a nitrogen stream, wherein the nitrogen is preheated via heat exchange with hot fluid from a chemical process, which process utilizes the oxygen product of the air separation. Preferably at least a part of the expanded nitrogen is utilized to preheat at least one fluid reactant of the chemical process. The chemical process may be gasification or direct reduction of iron oxide, as well as the conversion of natural gas into synthesis gas.

Abstract: A pump forms a pressurized stream of waste water, supplying it to a ring main which feeds the liquid to a plurality of conduits depending therefrom. Each conduit has a venturi whose throat has an inlet for gaseous oxygen formed therein. The throat of each venturi has a plurality of apertures through which gas is introduced from a chamber surrounding the throat. Each conduit ends in one or more nozzles immersed in a volume of liqud. Each venturi restricts the flow of water therethrough and creates turbulence so that a turbulent flow of liquid containing oxygen bubbles is emitted from the associated nozzle at relatively high velocity such that turbulence assisting the dissolution of oxyen is created in the volume of liquid.

Abstract: A mechanical pump having a pumping chamber within which is positioned a pair of intermeshing rotors, preferably of the claw type, with each rotor mounted for rotation on respective shafts and the first rotor being associated with an inlet to the pumping chamber and the second rotor being associated with an outlet from the pumping chamber, wherein the second rotor has a cavity in its surface immediately adjacent the outlet.

Abstract: Air is separated into oxygen and nitrogen in rectification columns 28 and 30. A stream of nitrogen is withdrawn from the top of the column 30 through an outlet 54, is warmed to about ambient temperature by passage through heat exchangers 34, 46 and 24, and is then heated at a pressure in the range 2 to 7 atmospheres absolute by heat exchange in heat exchanger 56 with a hot stream of fluid initially at a temperature of less than 600.degree. C. without said fluid undergoing a change of phase. The resulting hot nitrogen is then expanded in turbine 58 with the performance of external work, e.g. the generation of electricity.

Abstract: The present invention provides an apparatus having a high vacuum environment and a plurality of components located within the high vacuum environment so as to be exposed to high vacuum. At least one of the plurality of components is formed from a plastic material comprising liquid crystal polymer to prevent outgassing of the plastics material in the high vacuum environment.

Abstract: An improved boiler for liquefied gases comprises at least one heat transfer surface having means for creating a falling film of liquefied gas from its upper to lower end and means to heat the surface above the temperature at which the liquefied gas boils at the prevailing pressure. The subject apparatus is particularly suited for reboiling liquid nitrogen or liquid oxygen.

Abstract: In a membrane apparatus for separating a gas mixture, permeate gas is withdrawn from the vessel housing the membranes along passages whose extent along the flow path of the nonpermeate gas is only a fraction of the extent of such flow path. Thus, the gas mixture to be separated may be passed along the insides of a multiplicity of hollow fibres 8 whose walls are of a suitable membrane and cells 18 for the withdrawal of the permeate gas are defined by partitions 16 extending transversely to the fibres 8. Alternatively, an open-pored foamed plastics may be used instead of the partitions 16, or the gas may pass outside the fibres which are arranged transversely to the general direction of gas flow through the vessel, the permeate gas being withdrawn along the inside of each hollow fibre.

Abstract: A vacuum pump comprising a pumping chamber having an inlet and an outlet through which gas from an enclosure connectible to the inlet can be pumped, in which means are provided to allow the selective introduction through the chamber of a flow of recirculating purge gas to effect pumping of the chamber, the means preferably being such that the recirculating purge gas is produced in a gas circuit including the inlet and the outlet and also including a filter.

Abstract: The present invention provides a coldhead drive unit for a cryogenic refrigerator including a casing having an inlet for supplying a fluid into the casing at a working pressure and a valve positioned within the casing for controlling the supply of the fluid to and from the cold head. The valve comprises a valve plate and a valve head positioned against the valve plate and having a surface distal to the valve plate against which the working pressure acts. An effective pressure of less pressure than the working pressure acts at the interface between the valve head and the valve plate so that an axial force is exerted upon the distal surface of the valve head, driving the valve head against the valve plate. Additionally, a motor is included having a drive shaft for rotating the valve head against the valve plate.

Abstract: An improved process and apparatus for separating air to form oxygen and nitrogen in at least one cryogenic distillation column is disclosed. Nitrogen vapor taken from the colunm is warmed in countercurrent flow to incoming air in a heat exchanger wherein compressed air is being cooled for separation. A portion of the warm nitrogen is compressed, cooled in the heat exchanger and passed through an expansion turbine. The expanded nitrogen is passed through a reboiler associated with the column and further cooled in the heat exchange means. Part of the resulting liquid nitrogen is used to provide reflux for the column and the remainder is taken as product. Preferably, at least a portion of the compressed air stream is expanded in a turbine, passed through the reboiler associated with the column to provide reboil therefor, liquified by heat exchange and introduced to the distillation column through a throttling valve.

Abstract: A method and apparatus for the separation of air by pressure swing adsorption utilizing two beds of adsorbent material which are operated out of phase, thereby providing a more or less continuous flow of product oxygen with reduced argon content. A first adsorbent bed comprises a carbon molecular sieve which adsorbs oxygen more rapidly then nitrogen. The adsorbed oxygen is desorbed from the first bed and flows to a second bed, comprising a zeolite molecular sieve that adsorbs nitrogen preferentially to oxygen, thereby producing product oxygen as the non-adsorbed gas. Alternatively, the second bed comprises a carbon molecular sieve, and the adsorbed oxygen is desorbed as the oxygen product gas.