Abstract: A gas treatment method and apparatus for use in connection with processes of etching semiconductor devices or of plasma enhanced chemical vapor deposition onto semiconductor materials. In accordance with the method and apparatus, the exhaust gases are introduced into first and second stages while heating the first and second stages. The stages can be contained within a heated cartridge. The first stage contains silicon or a silicon-rich alloy or a silicon-rich substance in a particulate form and a partial coating of copper or a copper rich substance in intimate contact with the silicon, the silicon-rich alloy or the silicon-rich substance. The second stage contains calcium oxide, a calcium oxide containing material, or a soda lime containing medium.

Abstract: This invention relates to gas treatment apparatus and methods and particularly, but not exclusively, to such apparatus and methods for use with exhaust products from semi-conductor manufacturing process.A reactor column 10 has an inlet 11 at the bottom and an outlet 12. Between the inlet and outlet it is divided into three sequential stages containing: silicon or silicon containing materials; lime or soda lime and copper oxide or copper oxide reagents.

Abstract: Frozen solid particles are obtained from liquids such as dairy produce, liquid egg, microbiological cultures and pharmaceuticals, by direct contact with liquid nitrogen in an enclosed insulated vessel which includes nozzles for injection of liquids into conduits with contact channels additionally cooled by countercurrent flow of liquid nitrogen in cooling channels. A separation auger removes partially frozen product from the liquid nitrogen and completes its freezing by contact with cold nitrogen gas.

Abstract: Apparatus for dispensing metered quantities of liquefied gas such as liquid includes a thermally-insulated reservoir having at its bottom an outlet passage leading to a dispensing orifice outside the thermal insulator. There is a single valve for controlling admission of the liquefied gas to the dispensing orifice. The passage is in heat conductive relationship with a block of heat conductive material in the liquefied gas so as to maintain the passage sufficiently cold to prevent substantial evaporation of liquefied gas within the part of the passage with the reservoir. The valve may be cam or solenoid actuated to dispense drop of liquefied gas of chosen volume.

Abstract: A shielding gas for use in electric arc welding is disclosed. The gas comprises a mixture of helium, argon, 1.75% to 2.25% carbon dioxide and 0.25% to 1.0% oxygen (by volume). Use of the gas enables slag-free welds which accept readily paint applied by an electrostatic deposition process.

Abstract: In the manufacture of moulds or mould cores, refractory sand, a resin binder and a catalyst are passed into a mixer to form a freeflowing mixture from which the moulds or mould cores are made. As the sand is fed into the mixer it is cooled by contact with an atmospheric gas in liquid or solid state or the cold vapour of such a gas so as to keep the temperature of the sand as it enters the mixer below that at which the resin cures. To enable the sand to be delivered below a chosen temperature from a quarry to a foundry where the sand is used, the sand after quarrying and drying is fluidized by air, an atmospheric gas in liquid or solid state being introduced into the fluidizing air so as to lower its temperature.

Abstract: A cutting apparatus for cutting a longitudinally extending member such as rail comprises a frame; means for clamping the frame to the member to be cut; and a cutting torch which is pivotally attached to the frame. A pivoted torch holder is provided having bearing means permitting axial displacement of the torch relative to the member to be cut. The precise axial distance of the tip of the torch relative to the member to be cut is determined throughout the making of the cut by means comprising a plate attached to the frame and defining a cam surface and a cam follower connected to the torch. The shape of the cam surface thus makes it possible for the path described by the tip of the torch to conform, if desired, to the profile of the member to be cut.

Abstract: A fluid-flow restricting apparatus for mixing fluids employs a body member housing elongate flow restrictors (typically capillary tubes) which restrict the flow of the fluid therethrough. Demountable fluid-tight seals are provided between the capillary tubes and passages in the body in which the tubes are housed. An inlet header is demountably attached to the body so as to distribute fluid to the capillary tubes. There is a common outlet passage communicating with the outlet ends of the capillary tubes. The inlet header may be fed with the fluids to be mixed from a pressure regulation system and has several inlets. Valves are operable to select which header inlets are placed in communication with the respective fluids to be mixed.

Abstract: An air separation process for obtaining high purity oxygen and nitrogen comprises the steps of cooling compressed air in a heat exchanger to remove its water content; removing carbon dioxide from the dried air in an adsorption unit; further cooling the dry CO.sub.2 -free air and passing the residue to a rectification column; regenerating the beds of the adsorption unit with waste nitrogen from the rectification column; and purging water from the heat exchanger with the effluent gas obtained from regeneration in the adsorption unit.

Abstract: In a gas separation process a pressurized gaseous mixture is passed through a first bed of adsorbent while a second bed is being regenerated by desorbing gas therefrom and venting or discharging such gas from the second bed. The adsorbent is of such a character that one component of the gaseous mixture is preferentially adsorbed. The non-adsorbed component or components are collected as product. After a chosen time flow of gas into the first bed and out of the second bed is stopped, and the two beds are placed in communication with one another through a flow restrictor means so as to reduce the pressure difference therebetween. The flow restriction means is effective to prevent fluidization of the beds. The intercommunication between the two beds is stopped before the pressure difference therebetween has been eliminated and the gas mixture is then passed through the second bed, while the first is regenerated. The pressure difference between the two beds is then reduced and the cycle of operations repeated.

Abstract: Moulds are made from refractory sand (or other particulate or granular material) obtained from that sand or material. In order to control the temperature of the sand used to form the new moulds, the sand is heat exchanged with a permanent gas in liquid or solid state, or the cold vapour thereof. The temperature of the sand is sensed. The heat exchange is controlled so as to keep the sensed temperature at or below a chosen maximum.

Abstract: In the manufacture of clay or refractory ware containing oxidizable material, stacks of the ware are passed through a tunnel kiln and a flow of air passed over the stacks. Fuel burners are operated to provide the necessary stages for firing the ware. These stages include an oxidation stage in which residual oxidizable material is oxidized. Gas containing more oxygen than air (i.e. commercially pure oxygen or oxygen-enriched air) is introduced into the region of the kiln where the oxidation takes place. The oxygen-rich gas is caused to penetrate at least one stack for the time being in the oxidation region so as to increase the concentration of oxygen throughout the individual items of ware within said stack. It is thus possible to oxidize all the residual oxidizable material. At least 50% of such oxidation is typically confined to a temperature range of 100.degree. C. The heat thereby released assists in the firing of the ware.

Abstract: A gas-operated motor adapted to be driven by gas evaporated from a reservoir of liquefied carbon dioxide or the like. In order to overcome the problems generally associated with such motors due to the cooling of the gas as it evaporates from the liquid state in the reservoir and expands in the working chamber(s) of the motor, a chamber holding a substance which undergoes a change of state to release heat to the gas in operation of the motor is included. More particularly this chamber is located to be in heat conductive relationship both with the working chamber(s) of the motor and with a tortuous passage through which gas is supplied to the working chamber(s) and wherein superheating of the gas prior to its introduction to the working chamber(s) takes place.

Abstract: In the manufacture of moulds or mould cores, refractory sand, a resin binder and a catalyst are passed into a mixer to form a free-flowing mixture from which the moulds or mould cores are made. As the sand is fed into the mixer it is cooled by contact with an atmospheric gas in liquid or solid state or the cold vapor of such a gas so as to keep the temperature of the sand as it enters the mixer below that at which the resin cures. To enable the sand to be delivered below a chosen temperature from a quarry to a foundry where the sand is used, the sand after quarrying and drying is fluidized by air, an atmospheric gas in liquid or solid state being introduced into the fluidizing air so as to lower its temperature.

Abstract: In order to decarburize ferrous metal without recourse to an exothermic generator, an inert gas (typically nitrogen), water and a liquid or vaporous compound of carbon, hydrogen and oxygen (typically methanol) are admitted to a working chamber of the heat treatment furnace in which the metal is situated. The decarburization is preferably performed at 700.degree. to 800.degree. C. The methanol and water react to form a non-oxidizing, decarburizing atmosphere at the decarburizing temperature. The metal may be oxidized at a temperature below 600.degree. C. in another chamber of the furnace, the atmosphere from the decarburizing chamber being passed into the oxidizing chamber.

Abstract: A portion of a component of a gas stream is condensed with the remaining non-condensed gas stream being passed to an adsorber. The remainder of the component in the non-condensed stream is adsorbed in the adsorber and in a later stage of the adsorber cycle, the adsorbed component is desorbed and supplied to the inlet of a condenser together with the gas stream to promote condensation of the component by providing an increased concentration of the component in the gas stream.

Abstract: In a process for thermally cracking waste sulphuric acid, a combustible material is mixed with such acid and the mixture is supplied to a burner to which a flow of atomizing air is also supplied. A flow of secondary air which is enriched to about 23-40% by volume of oxygen is injected into a flame generated by burning said waste sulphuric acid-combustible material mixture to thereby thermally crack such acid while reducing the production of by-product sulphur trioxide.

Abstract: An apparatus for removing gas from a liquid such as sewage comprises a siphon having a rising leg 2 arranged coaxially within a falling leg 3. Depending into the siphon from a closure member 4 is a skirt 5. A gas extraction pump 6 is in communication with the siphon by means of a tube 7 which extends through closure member 4 at a location outside the skirt 5. Any foam drawn through with gas in the liquid when the pump 6 is operated will have to pass through liquid since the vacuum is drawn from the pump 6 at a location outside the skirt 5.

Abstract: In a process for producing nitric acid, a mixture of oxygen, nitrogen, nitric oxide, nitrogen dioxide, and dinitrogen tetroxide is introduced into an absorption column into which cold oxygen (below 0.degree. C.) is introduced. H.sub.2 O is introduced into the upper reaches of the column and reacts with the nitrogen dioxide and dinitrogen tetroxide to form nitric acid. The low oxygen temperature helps to shift the equilibrium between nitric oxide and oxygen to dinitrogen tetroxide and in favor of reacting the latter with water to form nitric acid.

Abstract: A volume-cycled lung ventilator providing for both spontaneous breathing of a patient and intermittent mandatory ventilation, the invention provides two parallel inspiratory flow paths, one flow path including a demand valve for supplying gas to the patient during spontaneous breathing and the other flow path including a solenoid-operated inspiratory flow valve for providing intermittent mandatory breaths. The invention provides structure capable of adjusting the intervals between mandatory breaths, the volume of each such breath and the flow waveform of each such breath. An expiratory flow path including a fluid operated expiratory flow valve is further provided. A flow rate signal generator in the expiratory flow path acts to sense the rate of exhalation of the patient and is effective to inhibit the opening of the inspiratory flow valve unless the rate of exhalation is below a predetermined value.