Abstract: Silicon thin films of superior resistivity useful for, e.g., semiconductor elements in solar cells, are formed by coating and drying silicon vaporized in the presence of hydrogen alone or hydrogen and an inert gas, followed by contacting the thus produced silicon particles with solvent to form a silicon colloid. Preferably, the silicon colloid is produced by a process which comprises vaporizing silicon in an atmosphere consisting essentially of hydrogen and up to 10 mol of an inert gas per mol of hydrogen; condensing silicon vaporized in the first step to form fine silicon particles; bringing the silicon particles into contact with a solvent to cover the silicon particles with solvent, and collecting the solvent covered silicon particles to obtain the silicon colloid.

Abstract: A micromechanical structure is etched on a component that has been introduced into a container having a plurality of inlet and discharge openings. The liquid etchant is displaced downwardly through a liquid discharge at the underside of the container by admitting water through the liquid inlet at the upper side, whereby no turbulence occurs in the liquid flow. The water employed as a rinsing agent is displaced by a liquid having a lower density such as, for example, ethanol or acetone. Finally, a liquefied gas, for example liquid carbon dioxide, is admitted via the liquid, this gas is evaporated by heating the container above the critical temperature, the pressure in the inside of the container is reduced to the ambient air pressure by opening a gas discharge, and the component is removed from the container through a sluice or lock.

Abstract: In accordance with the invention, phosphorous vapor is provided by in situ conversion of red phosphorous to white phosphorous and permitting the flow of vapor from said white phosphorous. The conversion is effected in a low pressure cell having a high temperature region for evaporating red phosphorous and a low temperature region for condensing the resulting vapor into white phosphorous. At room temperature equilibrium, the vapor pressure is dominated by the white phosphorous.

Abstract: An anhydrous ammonia gas sampler and concentration system (10) and method is disclosed that facilitates the collection and evaporation of large volumes of anhydrous ammonia in a safe, clean environment. The ammonia is collected and frozen in two containers (12, 14) connected in series and immersed in a liquid nitrogen bath (42). The frozen ammonia is evaporated through a very slow evaporation process after the containers are removed from the liquid nitrogen bath. The resultant contaminant concentrate provides the means by which a more accurate calculation of the percentage of contaminants in an ammonia sample may be made.

Abstract: A sublimation apparatus and process for separating solids and high boiling liquids are disclosed wherein a temperature gradient is imposed along the length of the vertically oriented, evacuated tube-shaped vessel or container and means for collecting and/or monitoring fractions of sublimate along the length of the sublimer vessel are provided.

Abstract: The invention provides a method of producing ultra-fine particles and an apparatus therefor. A particle carrier is moved in a chamber which is decompresed and charged with inert gas. An evaporable material is heated so as to deposit evaporated ultra-fine particles onto a part of the moving particle carrier. The deposited ultra-fine particles are collected from the part of the moving particle carrier while evaporated ultra-fine particles deposit onto another part of the moving particle carrier.

Abstract: A method of treatment of a high-level radioactive waste comprising heating the radioactive waste at a high temperature of about 500.degree. to 3000.degree. C. to vaporize part of the elements contained in the radioactive waste, and cooling the resultant vapor to separately collect the elements. In one embodiment, the heating step is replaced by a reduction-heating step wherein heating is carried out in the presence of a reducing agent, e.g. hydrogen. In another embodiment, the heating step may be followed by the reduction-heating step.

Abstract: Disclosed is a process for preparing crystals of anhydrous sodium sulfide, the process being characterized in that the process comprises the steps of heating crystals of polyhydrate of sodium sulfide under a pressure of about 500 torr or less at a temperature varying not more than .+-.about 10.degree. C. from the phase transition point between polyhydrate crystals and monohydrate crystals of sodium sulfide for about 2 hours or longer and further heating the monohydrate under atmospheric or reduced pressure at about 90.degree. to about 200.degree. C. for about 2 hours or longer.

Abstract: Process for the fine purification of fission molybdenum, dissolved in ionic form together with ions of the fission products of I, Sn, Ce, Ru and Zr in aqueous mineral acid solution, in which the fission molybdenum is fixed by a metal oxide in a sorption step and is then released in a desorption step, comprising: (a) passing the aqueous solution over an amphoteric oxide to sorb the ions of Mo, I, Ce, Ru, Sn and Zr, (b) drying the resulting charged oxide and thereafter heating the dried oxide to a temperature of about 1200.degree. C. to about 1300.degree. C. to sublimate the Mo, and at the same time passing a carrier stream containing water vapor and oxygen over the charged oxide to take up the Mo, and (c) desublimating Mo out of the carrier gas stream by cooling to a temperature below 600.degree. C., and followed by further cooling to room temperature, dissolving the resulting Mo residue in an aqueous solution of a strong alkali to form a molybdate solution.

Abstract: A process for obtaining essentially cone-shaped aluminum chloride granules free of fines from a gas current containing aluminum chloride, comprising contacting said gas current with a surface whose temperature is below about 70.degree. C. to deposit the aluminum chloride thereon in the form of cone-shaped granules and then heating said surface for a time and at a temperature sufficient to detach said granules from said surface; and the essentially cone-shaped product of such process.

Abstract: The process and the device according to the invention relate to the introduction, at a stable, known flow rate, of sublimable tetrachloride into a column for continuous extractive distillation under pressure of the chlorides. The sublimable tetrachloride is dissolved in a hot dissolver in a liquid solvent such as KAlCl.sub.4, and is then recirculated by pump at a stable, known flow rate into an evaporator connected to the column. The solution is then heated in an evaporator in order to sublime the majority of the product which it contains, the sublimed vapors thus passing into the column at a stable, known flow rate. The process according to the invention is adapted, in particular, to a plant for the production of ArCl.sub.4 of nulear purity and of HfCl.sub.4.

Abstract: Substrates such as semiconductor wafers are treated with a gas by advancing the substrate along a path, preferably a circular path through the gas while maintaining a face of the substrate transverse, preferably oblique, to the path so taht the gas contacts be exposed from the face of the substrate. Preferably, a plurality of substrates are treated simultaneously, and the substrates serve as vanes to impel the gas into rotational motion, thereby pumping the gas through the process chamber. Preferably, the substrates are carried on susceptors having generally planar faces, the susceptors also serving as vanes impelling the gas into rotational motion. The gas may be a depositing gas for forming epitaxial layers on the faces of the substrates, or an etching gas.

Abstract: Substrates such as semiconductor wafers are treated with a gas by advancing the substrate along a path, preferably a circular path through the gas while maintaining a face of the substrate transverse, preferably oblique, to the path so that the gas contacts be exposed from the face of the substrate. Preferably, a plurality of substrates are treated simultaneously, and the substrates serve as vanes to impel the gas into rotational motion, thereby pumping the gas through the process chamber. Preferably, the substrates are carried on susceptors having generally planar faces, the susceptors also serving as vanes impelling the gas into rotational motion. The gas may be a depositing gas for forming epitaxial layers on the faces of the substrates, or an etching gas.

Abstract: A sublimation apparatus comprising an inner vessel placed within an outer vessel leaving an interspace between them. Inlets and outlets for a gas to be treated are connected to the inner vessel. Plurality of parallel-connected heat exchange channels are provided around the inner vessel, which heat exchange channels are connected to a bottom header and to a top header. A heat exchanger is placed in the top header. The apparatus further has a first reservoir for a first heat exchange medium. A closable connecting duct connects the bottom header and the first reservoir, and another connecting duct connects a vapor space of the first reservoir and the top header. A second reservoir for a second heat exchange medium different from the first heat exchange medium is connected by a closable connecting duct to the interspace between the inner and outer vessels. A closable connecting duct connects a vapor space of the second reservoir with the top portion of the interspace.

Abstract: Liquid white phosphorus is distilled from red phosphorus in vacuo at 480.degree.-490.degree. C. The vapor is transferred in a conduit maintained at 250.degree. C. and condensed into liquid white phosphorus at room temperature. The liquid white phosphorus is then filtered to eliminate any condensed red phosphorus. The clear, colorless phosphorus produced may be utilized as a source of P.sub.4 species for chemical vapor deposition, sputtering, vacuum deposition, and molecular beam deposition of phosphorus, polyphosphide, and other phosphorus compound films for semiconductor and other applications including insulation and passivation.

Abstract: In a method of periodically heating a product separator of a plant for producing anhydride or maleic anhydride, a PA or MA product is deposited on cooling surfaces of the product separator. To melt the product, the cooling surfaces are indirectly heated by means of a heated liquid, which is circulated through the product separator. The liquid heat transfer medium is indirectly heated with steam in a heater for the heat transfer medium. At least during the time of the largest steam demand, most of that steam is taken from a steam accumulator, which is charged with steam supplied from the plant for producing PA or MA. The charging of the steam accumulator is effected to at least a substantial degree during the time in which the heater for the heat transfer medium is out of operation or is operated under a low load.

Abstract: Aluminum chloride gases and other gases from a processing system are directed to a cold trap including a blower connected thereto. The blower directs the gases, except for the aluminum chloride, out of the cold trap. The aluminum chloride is solidified in the trap. Means including a heater are provided to convert the solid aluminum chloride to a vapor and selectively empty the aluminum chloride out of the cold trap into another trap associated with means for chemically treating the aluminum chloride. The cold trap is then cooled and ready to receive additional aluminum chloride from the processing system.

Abstract: The present invention relates to the production of high-purity substances and, more specifically, to a process for a fine purification of sulphur hexafluoride from impurities.The process for a fine purification of sulphur hexafluoride comprises purification of sulphur hexafluoride by crystallization at a speed of displacement of the interphase boundary of from 1 to 50 mm/hr at a temperature of from 222.3 to 217.degree. K.; the liquid-phase concentrate formed during crystallization is subjected to sublimation purification under a pressure of from 210 to 1.3-0.13 KPa.The high-purity sulphur hexafluoride is useful in the high-voltage energetics as an insulation and arc-exctinguishing medium, as well as in electronics, laser engineering, metallurgy and medicine.

Abstract: A method and apparatus for making an antimony trioxide powder having a specific particle size distribution from crude antimony trioxide which contains a small amount of impurities having a higher vaporization temperature by passing the crude antimony trioxide through a plasma arc tail gas reaction zone, vaporizing in a chamber communicating with the reaction zone the antimony trioxide at a temperature that liquifies the impurities, exiting the gases from the chamber through one port, draining the liquified impurities from the chamber through the port, contacting the exiting materials with a quench gas, mechanically clearing the exit port of solidified impurities and separating the antimony trioxide powder from the other exiting materials.

Abstract: A device for producing solid aluminum chloride from gas containing gaseous aluminum chloride by means of a fluidized bed condenser. Between the inlet pipe for carrier gas and an outlet pipe for residual or waste gas there is a distributor plate with openings in the form of nozzles, at least one cooling facility, a feeding facility for the supply of gas containing gaseous aluminum chloride and a facility for drawing off the solid aluminum chloride. The outlet pipe for waste or residual gas is connected to the inlet pipe for carrier gas via a separator which separates out fine particulate aluminum chloride, which is then fed back to the bed to act as nuclei.

Abstract: Uranium hexafluoride having a high U-235 content is driven out of a transportation container by heating in a correspondingly heated container using a halogenated hydrogen free organic liquid as the heating medium. There is also provided an apparatus for carrying out the process comprising a container having a reflux condenser and an insert for holding the transportation container closed at the bottom by condensate outlet.

Abstract: This invention relates to an improved process for the separation and isolation of coffee aroma constituents from roasted coffee, combining the aroma constituents with an edible substance and subsequently incorporating the aromatized substance in a food product.The process involves improving the condensation of vapors generated from the distillation of coffee oil by condensing the distilled aroma constituents onto a sleeve cooled by and snugly surrounding a container filled with coolant. The sleeve is removed and the aroma constituents condensed thereon are then preferably combined with an edible substance by manipulating the condensed constituents quickly and efficiently thus minimizing aroma loss and degradation caused by undesirable prolonged contact with air.

Abstract: Submicron-sized oxide particles are produced in a process in which coarse particles are fed into a vaporizing zone of a plasma burner, where they sublimate and finer particles are produced in a cooling zone.

Abstract: This invention relates to an improvement in an apparatus for ammonia feed in copying equipment with a cold trap, for freezing out ammonia and water from air extracted from the immediate vicinity of a developing chamber, in particular from pre-chambers, together with a rectifying column for releasing ammonia from the frozen-out ammonia-water mixture and recycling the gaseous ammonia into the developing chamber, the improvement comprising heat exchanger means,With two heat-conducting channels adjacent each other through which the extracted air flows counter-currently, a cold source inSaid heat exchanger means, said source being at a transition position between said channels and surrounded thereby, heat source meansAdapted to heat said heat exchanger means, outlet means on said heat exchanger means, means connecting said outlet means on said heat exchanger means to said rectifying column, and means connecting said rectifying column to said developing chamber.

Abstract: A method of producing epitaxial semiconductor monocrystal materials of silicon carbide with the silicon carbide crystals being grown by crystallizing sublimed silicon carbide vapors.

Abstract: A method and apparatus is disclosed for freezing and subliming uranium hexafluoride (UF.sub.6) as part of a gaeous diffusion plant from which a quantity of the UF.sub.6 inventory is intermittently withdrawn and frozen to solidify it. A plurality of upright heat pipes holds a coolant and is arranged in a two compartment vessel, the lower compartment is exposed to UF.sub.6, the higher one serves for condensing the evaporated coolant by means of cooling water. In one embodiment, each pipe has a quantity of coolant such as freon, hermetically sealed therein. In the other embodiment, each pipe is sealed only at the lower end while the upper end communicates with a common vapor or cooling chamber which contains a water cooled condenser. The cooling water has a sufficiently low temperature to condense the evaporated coolant. The liquid coolant flows gravitationally downward to the lower end portion of the pipe. UF.sub.6 gas is flowed into the tank where it contacts the finned outside surface of the heat pipes.

Abstract: A gas mixer is disclosed which is used for mixing different gases in order to obtain a solid by sublimation or chemical reaction. The mixing is carried out in a mixing chamber having a uniform, substantially circular, cross section and a length depending on the particular application. Build up of the solid is prevented by injecting the gases to be mixed into the mixing chamber so that the combined flow in the duct, at its inception, is characterized by an axial flow of one gas surrounded by a spiralling flow of another gas. Thus, the gases to be mixed will first meet in the vicinity of the center of the duct at what may be termed a shear layer and the shear layer will progressively spread outwardly to the mixer surfaces downstream of the point of injection of the gases into the mixing chamber. The bulk of the solid formation in the duct is in the vicinity of the center of the duct which prevents the formation of solid on or near the mixer surfaces where it would tend to adhere or deposit and cause build ups.

Abstract: The method of preparing sulphuric acid comprises distilling sulphur trioxide with subsequent sublimation condensation by cooling with a coolant having a temperature of from -5.degree. to -15.degree. C. The obtained sulphur trioxide is then treated with sulphuric acid having a concentration in the range of 95 to 96 per cent. The thus prepared sulphuric acid contains impurities in the range of 10.sup.-7 - 10.sup.-8 per cent by weight of cations, and 5.times.10.sup.-5 per cent by weight of anions, SO.sub.3 " in particular.

Abstract: This invention relates to an improved process for the separation and isolation of coffee aroma constituents from roasted coffee, combining the aroma constituents with an edible substance and subsequently incorporating the aromatized substance in a food product.The process involves improving the condensation of vapors generated from the distillation of coffee oil by condensing the distilled aroma constituents onto a sleeve cooled by and snugly surrounding a container filled with coolant. The sleeve is removed and the aroma constituents condensed thereon are then preferably combined with an edible substance by manipulating the condensed constituents quickly and efficiently thus minimizing aroma loss and degradation caused by undesirable prolonged contact with air.

Abstract: An apparatus for precipitating and separating a material in a solid form from a gaseous mixture. The substance which is settling in solid form can be very simply prevented from accumulating near the inlet by providing at least one channel with at least one controllable bypass.

Abstract: Apparatus for separating a sublimation product from a gas which contains this product in the form of vapor, comprising an elongate substantially horizontal casing having a gas inlet near one end and a gas outlet near the other end so that gas flows longitudinally through the casing; heat exchange means cooperating with the exterior of the wall of the casing for cooling said wall below the sublimation temperature during the subliming process, means for assuring that an open channel for gas flow is maintained during the subliming process, said means comprising at least one permanently heated, elongate, rod-shaped element fitted eccentrically in the casing, said element extending in the same direction as the casing and being placed in the upper part of the casing, said heating element being manufactured of a material having good heat-conducting properties and projecting into the casing through a wall portion over part of the length of the heating element so that heat can be supplied thereto from outside the casi

Abstract: An apparatus for recovering higher melting organic materials which is an upright column containing a gas inlet at a lower portion thereof and a gas outlet at the upper portion thereof. The apparatus has a wall disposed in the flow of the gas between the gas inlet and the gas outlet which wall is perforated to allow gas to flow therethrough. Cooling means are provided on the side of the wall away from the gas inlet to cool components of a gas flowing therethrough.

Abstract: A finned tube heat exchanger for isolating sublimates, especially phthalic anhydride, in which the finned tubes arranged in parallel alongside one another and above one another and connected by headers and tube bends permit flow through them successively in the first, then the third, then the second and then the fourth row, and that the transverse fins are arranged in rows staggered laterally in opposite directions by an amount corresponding to from half the spacing to the whole spacing between adjacent fin edges.

Abstract: A longitudinal epitaxial growth device for making a mixed crystal of III.sub.b -V.sub.b group intermetallic compound semiconductor in which a means for inverting the reaction gas flow is disposed between the gallium source and the substrate, the height of the device is reduced, and the length of the gas mixing band is made sufficiently long.

Abstract: A method and a device for vapor growing crystals. The crystals are grown in an evacuated ampoule from a liquified sample source material, such that the source material is separated from the growing crystal by one or more capillaries or the like which provide the only pathway between the sample source and the growing crystal. There is a temperature gradient between the sample source and the growing crystal such that the growing crystal is at a lower temperature than the sample source.

Abstract: Apparatus for separating a product of sublimation from a gas, in which this product is condensed in solid form on the cooling surface of a bank of parallel tubes of unequal length, so arranged that near the vapor inlet, where the solid deposits are first settling on the tubes, the distance between the tubes present there, is greater than in locations inside the apparatus farther from the inlet.

Abstract: Crude hydroquinone containing impurities is purified in a sublimation purification apparatus where the crude hydroquinone is introduced into a stirred and fluidized bed, a carrier gas which is inert to the hydroquinone is passed therethrough, and the temperature therein is kept at about 110.degree.-170.degree.C whereby crude hydroquinone is sublimed, and thereafter a mixed gas consisting of the sublimed vapor and the carrier gas is introduced into a condenser at a temperature at about 25.degree.-90.degree.C whereby the hydroquinone only is fractionally solidified. After the sublimation purification, hydroquinone of high purity can be collected.