Abstract: An apparatus for driving levitation coils of a magnetic bearing provided with a DC power source and a motor drive device powered by the power source. A DC motor is driven by the motor drive and the output from the motor is linked to a switching amplifier. The output from the amplifier is linked to the levitation coils of the magnetic bearing. A feedback control is provided from the magnetic bearing to the amplifier to position a rotor associated with the levitation coils in response to the amplifier output. The DC power source also directly powers the switching amplifier.

Abstract: A stream of compressed air is purified in a unit by removal of carbon dioxide and water vapour. The air is cooled by passage through a heat exchanger to a temperature suitable for its rectification. The air is separated in a higher pressure rectifier into oxygen-enriched liquid and nitrogen vapour. A stream of the oxygen-enriched liquid is reduced in pressure and introduced into a phase separator provided with a reboiler with the result that further separation takes place and a liquid further enriched in oxygen and an intermediate vapour are formed. A stream of the further-enriched liquid is separated into oxygen and nitrogen in a lower pressure rectifier. A stream of the intermediate vapour is condensed in a condenser and is introduced into the lower pressure rectifier.

Abstract: An anaesthetic vaporizer for supplying an anaesthetic to a patient and having an inlet for receiving carrier gas and an outlet for delivering carrier gas laden with the anaesthetic to the patient. The vaporizer includes a pump having an expandable body, preferably of a metal, and which expands to draw in the liquid anaesthetic from a reservoir through a valving mechanism and which collapses to meter a precise amount of that liquid anaesthetic into a chamber where it is vaporized for introduction into the carrier gas as it passes between the inlet and the outlet.

Abstract: A method is provided for treating sewage by introducing carbon dioxide and oxygen therein so that the carbon dioxide reduces the pH of the sewage to about pH5.0 or below and reduces the activity of bacteria therein such that the oxygen can oxygenate the sewage rather than be consumed by the bacteria. Generation of malodorous compounds is significantly reduced or prevented until the carbon dioxide is sufficiently dispersed so that the pH rises above about 5.0.

Abstract: A process of depositing thin film coatings by evaporation in which a plasma is formed in an evacuated chamber and a source of material to be evaporated is provided which is evaporated to produce evaporated material. A substrate to be coated is located within the chamber and the evaporated material is caused to pass through the plasma and be to be deposited on the substrate. The plasma is generated by a helicon wave.

Abstract: A vacuum pump of the scroll type having first and second scroll components each having a scroll structure defined thereon. The scroll components are arranged in the pump such that the respective scroll structures inter-engage with the first scroll component being held stationary and the second scroll component orbiting the first scroll component to trap a volume of gas and urge the volume from one end of the respective scroll structures to the other end. The first and second scroll components define inter-engaging scroll structures having an initial multi-start portion including at least two pump inlets and a subsequent single-start portion including a pump outlet.

Abstract: In a pressure swing adsorption plant for the production of oxygen enriched gas a pressure vessel contains a first bed of molecular sieve adsorbent located adjacent an outlet 4 of the vessel which has an optimum operating efficiency at approximately ambient temperature and a second bed 10 of molecular sieve adsorbent which has an optimum efficiency below that of ambient operating temperature located adjacent the inlet 2.

Abstract: A pressure swing adsorption apparatus (10) is provided with actuator air via a reservoir (40) which draws its supply either from one or more of the process vessels (12) after it has been dried thereby or directly from the system compressor (32). Controls are provided to ensure actuator air is preferentially drawn from the dried source and for ensuring instrument air is available even on start up of the apparatus.

Abstract: A container (2) for a liquid anaesthetic agent for supplying the agent to an anaesthetic vaporiser comprises a reservoir for the liquid agent, a valve (6) which, when closed, prevents the flow of the liquid agent from the reservoir, a tubular outlet (10) through which the liquid can leave the reservoir when the valve is open. An O-ring (20) at the free end of the conduit provides a sealing surface for forming a seal with a corresponding sealing surface provided at an inlet to a vaporiser to which the anaesthetic agent is to be supplied. A flange (22) engages a guide on the vaporiser, to retain the container in contact with the vaporiser.

Abstract: A non-intrusive device for attachment to a pipe or vessel through which a fluid flows for monitoring the accumulation of deposits on the interior surface of the pipe or vessel. The device comprises a tubular member having an internal cross-sectional configuration substantially matching that of the pipe or vessel. Additionally, the tubular member is made of an electrically insulating material and having associated therewith three spaced electrodes for monitoring the change of dielectric constant within the pipe or vessel.

Abstract: Method and apparatus for performing a metallurgical process in which a carbonaceous material is converted to a reducing gas and a metal is melted in a main reactor, particulate coal is partially oxidized in a secondary reactor to form a particulate char and a calorific gas under conditions which minimize the formation of carbon monoxide, and at least part of the char and some of the calorific gas are introduced into the main reactor.

Abstract: A hybrid vacuum pump comprising a turbomolecular stage positioned at the inlet end of the pump and comprising a stator formed from an array of stationary blades and a rotor formed from a further array of blades arranged for rotation at high speed between the stator blades. A molecular drag stage is positioned at the outlet (high pressure) end of the pump and comprises at least two discs arranged for rotation within a stator with a minimal clearance between the circumferential edge of the discs and the stator. A flow passageway linking the turbomolecular stage with annular channels is defined between the stator and opposing faces of the discs and projections extending from the stator are provided for deflecting gas being pumped from the annular channels during rotation of the discs.

Abstract: A clamp for securing adjacent lengths of pipe. The clamp incorporates a seal designed to incorporate a temperature or pressure probe. The clamp is circular and has upstanding end portions and a threaded rod member passing through apertures in the upstanding end portions to secure flange ends of the adjacent lengths of pipe together. The rod member has an opening through which the temperature or pressure probe passes so that temperature pressure can be measured within the adjacent lengths of pipe. Furthermore, seal components held by a support member can be provided to seal the support member to adjacent lengths of pipe. The temperature or pressure probe passes radially through such support member.

Abstract: A first flow of air is compressed in a first air compressor associated with a gas turbine and is purified in an adsorptive purification unit which separates water vapour and carbon dioxide from the air. The purified first flow of air is further compressed to a pressure at least 5 bar higher than that at which it is purified in a second air compressor whose outlet pressure is independent of fluctuations in the power output of the gas turbine, is cooled in a main heat exchanger, is passed through an expansion valve, and is introduced into a higher pressure rectification column. A second flow of air is compressed in a third air compressor which is independent of the gas turbine. The compressed second flow of air is purified in an adsorptive purification unit by the separation of water vapour and carbon dioxide therefrom. The purified second flow of air is cooled in the main heat exchanger and is introduced into the higher pressure rectification column.

Abstract: A pressure vessel 1 forming part of a PSA plant contains a molecular sieve adsorbent. A plurality of thermocouples are located within the molecular sieve adsorbent such that one junction 8 of each thermocouple is positioned adjacent the feed gas inlet 2 of the vessel 1 while the second junction 10 of each thermocouple is positioned adjacent the product gas outlet 4 of the vessel.

Abstract: A method for effecting the initiation of a molecular process or reaction in a substance, which comprises bringing the substance into contact with a surface of a cold cathode device and applying an electric potential across the cold cathode device to cause electrons to be emitted from the surface thereof with an energy level sufficient to effect the initiation.

Abstract: An anesthetic vaporizer is disclosed having an inlet for receiving carrier gas and an outlet for delivering carrier gas with an anesthetic agent to a patient. The vaporizer has a passage that extends between the inlet and the outlet, a vaporizing chamber and a passageway extending from the vaporizing chamber to the outlet. A means such as a differential pressure transducer monitors the differences in pressure between the carrier gas in the passage and the anesthetic agent in the passageway to control the flow of the anesthetic agent through the passageway.

Abstract: An apparatus comprising a liquid-vapor contact column housing an array of vertically spaced liquid-vapor contact trays and an arrangement of downcomers that conduct liquid from tray-to-tray down the array. In a vapor space between the trays there are liquid-vapor disengagement devices having vapor passages therethrough and defining surfaces for the flow thereacross of any liquid disengaged from vapor ascending the column. Each of the devices is typically provided by a sheet of expanded metal and has an outlet edge in liquid flow communication with the next lower tray via the downcomer.

Abstract: Apparatus (10) includes means (14) for exciting at least the fundamental radial circumferential mode of vibration (f.sub.1) and the first harmonic (f.sub.2) thereof, detection means (22) for detecting the vibration and analyzing means (12) for determining the internal pressure by reference to f.sub.1 and f.sub.2.

Abstract: Cooled and purified air is introduced into a higher pressure rectification column and separated into oxygen-enriched liquid and nitrogen vapor. A stream of the oxygen-enriched liquid is flashed through a pressure reducing valve to form a mixture of liquid further enriched in oxygen and vapor depleted of oxygen. The liquid is reboiled by reboiler. A stream of the further enriched liquid is reboiled in condenser and is introduced into a lower pressure rectification column for separation into oxygen and nitrogen products. Reflux for the columns and is formed by condensing in condenser nitrogen vapor separated in the higher pressure rectification column. A reboiler provides an upward flow of vapor through the column. The condenser and reboiler take the form of a single heat exchanger. The reboiler is located in a phase separator, the reboiler is located in a rectification column containing liquid-vapor contact devices above the level at which fluid issuing from the valve is introduced.