Abstract: An improved process for the production of oxides from hydrocarbons by reaction with oxygen, air or a gas enriched in oxygen relative to air, preferably the latter, in the presence of a suitable catalyst. An alkane, e.g. propane, is converted to an alkene in a catalytic dehydrogenator. The product stream is introduced into an oxidation reactor. Product formed therein is recovered in a conventional quench tower. The pressure of the gaseous effluent from the quench tower is raised and it is introduced into an absorber/stripper unit to form a recycle stream containing unreacted alkane and alkene as well as a minor amount of oxygen, typically 1-2 percent by volume, and a waste stream comprising the remainder of the quench tower gaseous phase. The recycle stream enters a selective oxidation unit wherein oxygen is removed, and the product recycled to the dehydrogenator.

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 A stream of nitrogen is withdrawn from the top of the column 30 through an outlet 54, is warmed to about ambient temperature by passage through heat exchangers 34, 46 and 24, and is then heated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 and method for ultrasonically testing the internal neck-shoulder region of a large number of gas cylinders for radially oriented defects. The apparatus and method includes housing an ultrasonic transducer within a shoe in a predetermined orientation wherein the transducer is wedged at a wedge angle so that ultrasonic pulses travel directly through the shoulder region to the top and bottom of the internal neck-shoulder region and is also outwardly skewed within the shoe at a skew angle such that the radially oriented defects reflect the ultrasonic pulses and produce return echoes. An automated scanner moves the shoe and therefore, the transducer in a predetermined pattern such that the entire internal neck-shoulder region of the gas cylinder is scanned. The scanner is supported by a stand that allows the automated scanner to be rapidly set up on the gas cylinders being tested.

Abstract: The present invention provides a method for cleaning articles by removing surface particulate matter from the articles. In accordance with the present invention, the articles are immersed in a bath of liquid cryogen, chemically non-reactive with the articles to be cleaned. Prior to immersion it is necessary to insure that the articles have a sufficiently high temperature above that of the liquid cryogen and during immersion it is also necessary to insure that the articles are immersed at a sufficient rate to insure that the liquid cryogen undergoes film boiling before undergoing nucleate boiling at the surfaces of the articles. The articles are left immersed so that nucleate boiling of the liquid cryogen occurs at the surfaces of the articles. During the nucleate boiling, the surface particulate matter is carried from the articles and into the liquid cryogen bath. After the articles have reached thermal equilibrium with the liquid cryogen, the articles are removed from the bath.

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: The present invention relates to an apparatus for delivery of pure gaseous and liquid forms of cryogen. The apparatus includes a pressure vessel for receiving a liquid form of the cryogen. A liquid-vapor interface is maintained within the pressure vessel by a liquid level detector and a cut-off valve connected to the level detector to vent the gaseous form of the cryogen to the atmosphere when the liquid form falls below a predetermined level. A heated overflow tube projects into the pressure vessel and is positioned at the predetermined level of the liquid. When the liquid rises above the predetermined level, it flowws into the overflow tube and is heated to vapor to add to the gaseous form of the cryogen within the pressure vessel. An outlet conduit is provided for delivering the gas and liquid forms of the cryogen from the pressure vessel. The conduit has a moveable end section located within the pressure vessel.

Abstract: Cyanide present in aqueous streams, such as effluents from electroplating and gold mining operations is reduced or elliminated by contacting the cyanide-containing stream with oxygen and carbon dioxide in the presence of cupric ions. The oxygen may be provided by air or oxygen and the contacting is carried out at until the pH of the aqueous stream is reduced to a value in the range of about 6 to 8 and preferably 6.5 to 7.5. Cupric sulfate has been found to be particularly effective for the described reaction.

Abstract: An improved process is provided for the production of nitriles from hydrocarbons by reaction with an oxygen-containing gas comprising oxygen, air or a gas enriched in oxygen relative to air and ammonia in the presence of a suitable catalyst. In the process, a selective separator provides recycle of a substantial portion of the unreacted hydrocarbon as well as for a controlled amount of a gaseous flame suppressor in the system. The gaseous flame suppressor comprises a substantially unreactive hydrocarbon containing 1 to 5 carbon atoms, carbon dioxide and nitrogen when present in the feed to the ammoxidation reactor. The use of air or oxygen-enriched air in the feed to the ammoxidation reactor is particularly advantageous from an economic view in combination with a pressure swing adsorption unit as the selective separator. The process is characterized by high selectivity to the formation of the product.

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: The present invention provides an electron beam evaporation source designed so that the size of the impact area of the electron beam on an evaporant will remain essentially constant in any position of the impact area on the evaporant; and thus, the rate of evaporation will remain essentially constant. To this end, a quadrapole comprising a set of two pairs of electromagnets is used to deflect the electron beam. The quadrapoles provide a uniform magnetic deflection field to prevent distortion of the impact area. A pair of pole pieces, used in deflecting the electron beam through an arc of 270 degrees, are provided with a predetermined thickness and spacing to prevent lengthening of the impact area parallel to the pole pieces as the electron beam is deflected parallel to the pole pieces. The pole pieces, however, produce the formation of tail regions in the impact area when the impact area is positioned near the pole pieces.

Abstract: An improved process is provided for the production of oxides from alkanes by reaction with oxygen, air or a gas enriched in oxygen relative to an air in the presence of an oxidation catalyst. An alkane, e.g. propane, is converted to an alkene in a multistage dehydrogenator. The product stream is withdrawn from an intermediate reactor in the dehydrogenator, other than the first and the last reactor, and introduced into an oxidation reactor. The product formed in the oxidation reactor is recovered in a conventional quench tower. The gaseous effluent from the quench tower is treated in a pressure swing adsorption (PSA) unit to form a gaseous stream containing the unreacted alkane and alkene as well as a minor amount, i.e. less than about 2 percent by volume, of oxygen and nitrogen, if present in the feed to the oxidation reactor.

Abstract: An improved process is provided for the production of oxides from hydrocarbons by reaction with oxygen, air or a gas enriched in oxygen relative to air, preferably the latter in the presence of an oxidation catalyst. An alkane, e.g. propane, is converted to an alkene in a catalytic dehydrogenator. The product stream is introduced into an oxidation reactor. The product formed therein is recovered in a conventional quench tower. The gaseous effluent from the quench tower is treated in a separator to produce an adsorbed stream, an oxygen-enriched stream, a waste stream and, if desired, a hydrogen-enriched stream. The oxygen-enriched stream may be recycled to the oxidation reactor depending on the nitrogen content thereof. The adsorbed stream plus at least a portion of the hydrogen-enriched stream is introduced into a selective oxidation unit to remove the remaining oxygen and then recycled to the dehydrogenator. The remainder of the hydrogen-enriched stream, if any, may be taken as product or vented.

Abstract: The present invention provides a water cooled crucible adapted to be received in a crucible support element of an electron beam evaporation system. The crucible comprises a base wall and a sidewall upstanding from the base wall to form a rim and pocket located between the rim and the base wall for containing molten material to be evaporated. The support element has an inner surface surrounding the sidewall of the crucible to define an annular passage for circulating cooling water in a direction taken from the rim to the base wall of the crucible. The sidewall includes a thickened region positioned to conduct heat generated at the top surface of the molten material and having a thickness such that the outer surface contacts the inner surface of the support element. The thickened region has a plurality of circumferentially spaced, preferably spiral grooves defined at the outer surface of the thickened region.

Abstract: The present invention provides a cryogenic storage container having a pressure vessel surrounded by a vacuum vessel for maintaining a vacuum between the outer wall of the vacuum vessel and the pressure vessel. A pair of intermediate and sub-intermediate heat shields are disposed between the outer wall of the vacuum vessel and the pressure vessel for intercepting the heat that would otherwise be transferred from the vacuum vessel to the pressure vessel. The heat intercepted by the intermediate heat shield is absorbed by liquid nitrogen contained within a liquid nitrogen container. The heat intercepted by the sub-intermediate heat shield is preferably absorbed by liquid neon in a liquid neon storage tank. The liquid nitrogen and neon absorb heat by undergoing a phase change, from liquid to vapor. In order to prevent failure of the liquid nitrogen container, the nitrogen is vented to the atmosphere over a period of time.

Abstract: Highly purified gaseous hydrogen and liquid carbon dioxide are produced from a steam reformer/shift converter by passing the effluent from the latter through a multibed hydrogen PSA unit followed by an uncoupled carbon dioxide PSA unit. The carbon dioxide PSA unit produces a hydrogen-rich stream which is recycled to the feed to the steam reformer, a carbon dioxide-rich recycle stream which is recycled to the carbon dioxide PSA unit feed and a carbon dioxide-rich product stream which is introduced under pressure to a liquifier. A waste stream from the liquifier is recycled to the carbon dioxide PSA unit feed. A portion of the carbon dioxide-rich product stream is withdrawn from the compressor at a stage such that its pressure is higher than that of the carbon dioxide PSA unit and returned thereto as a cocurrent purge preceding bed regeneration to obtain product.

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 covering for a hydraulic ram of a freeze dryer. The freeze dryer of the present invention includes a pressure vessel having a sterile freeze drying chamber for receiving a stack of containers holding a sterile material to be freeze dried. A pressure plate located within the freeze drying chamber is adapted to be driven against the stack of containers for mechanically stoppering the containers. A hydraulic ram is connected to the pressure vessel and has an actuating arm projecting into the freeze drying chamber. The actuating arm is connected to the pressure plate and is extendible for driving the pressure plate against the containers and retractable for removal of the containers from the pressure vessel. The actuating arm has a non-sterile surface that could contaminate the freeze drying chamber and therefore, the sterile material could be freeze dried.

Abstract: An improved process is provided for the production of oxides from hydrocarbons by reaction with oxygen, air or a gas enriched in oxygen relative to air, preferably the latter, in the presence of an oxidation catalyst. An alkane, e.g. propane, is converted to an alkene in a dehydrogenator. The product stream is introduced into an oxidation reactor. The product formed therein is recovered in a quench tower. The gas phase from the quench tower is treated in a PSA unit to form a gaseous stream containing the unreacted alkane, alkene, a minor amount of oxygen, i.e. less than about 2 percent by volume, and nitrogen if present in the feed to the oxidation reactor. The gaseous stream, which may or may not contain hydrogen depending on the adsorbent on the PSA unit, is introduced into a selective oxidation unit to remove the remaining oxygen and then recycled to the dehydrogenator.

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.