Abstract: A process for preparing isocyanates in the gas phase, in which the mixing of the reactants and thus the reaction conditions are significantly improved by means of hydrodynamic measures such as increasing the turbulence of the feed stream in the central nozzle. As a consequence, the necessary residence time in the reactor and thus the length of the reactor are reduced and the formation of polymeric by-products which lead to caking in the reactor and a shortening of the operating period of the reactors is avoided.

Abstract: The present invention relates to a method for producing highly pure, granular silicon with a narrow particle-size distribution by decomposing silanes or halosilanes in a fluidised bed and epitaxially growing silicon on silicon seed particles, which method is characterised in that the gas containing silicon is supplied to the reaction chamber in an upward flow and the contents of the fluidised bed are separated in a continuous or discontinuous manner, whereby a particle stream from the fluidised bed is supplied to a separator mounted outside the fluidised bed, particles of the desired size are separated and undersized particles are returned to the fluidised bed. The invention also relates to a device and the use thereof for carrying out said method.

Abstract: A cyclone separator (14) for use in a suction apparatus (4) of a hand-held power tool (2) includes a dirty air inlet (12), a suction ventilator (38) for aspirating, through a suction opening (8) which is connected with the dirty air inlet (12), abrasion particle-carrying suction air, a pure air outlet for letting out purified air, a vortex chamber (16) arranged between the dirty air inlet (12) and the pure air outlet, with the dirty air inlet (12) opening substantially tangentially into the vortex chamber (16) for generating a swirling stream in a direction toward the pure air extraction element (24), a collection chamber (36), and particle outlet having at least two particle outlet openings and connecting the vortex chamber with a collection chamber (36), with the dirty air inlet opening into the vortex chamber between the two particle outlet openings.

Abstract: A device for electrically heating a vertically erect chamber comprising several heating zones arranged vertically one above the other. The components of the device, with the exception of the insulating components, are made from graphite materials. Each zone (Z) comprises a number of supports (1), arranged in an essentially even distribution around the chamber for heating, which simultaneously serve as electrical supplies for the heater, and the heater for each zone (Z) is fixed at one end and longitudinally displaceable at the other end.

Abstract: The invention relates to a device for electrically heating a vertically erect chamber, for example, a reactor, to high temperatures (?1000° C.) and/or with high power (30 to 1000 kW per zone), comprising several heating zones arranged vertically one above the other. The components of the de- vice, with the exception of the insulating components, are made from graphite materials. The aim of the invention is to embody and develop the device such that the largest possible degree of stability and functional capability for the whole device is achieved with low constructional complexity. The device should in particular be capable of heating very tall chambers.

Abstract: A cyclone separator (14) for use in a suction apparatus (4) of a hand-held power tool (2) includes a dirty air inlet (12), a suction ventilator (38) for aspirating, through a suction opening (8) which is connected with the dirty air inlet (12), abrasion particle-carrying suction air, a pure air outlet for letting out purified air, a vortex chamber (16) arranged between the dirty air inlet (12) and the pure air outlet, with the dirty air inlet (12) opening substantially tangentially into the vortex chamber (16) for generating a swirling stream in a direction toward the pure air extraction element (24), a collection chamber (36), and particle outlet having at least two particle outlet openings and connecting the vortex chamber with a collection chamber (36), with the dirty air inlet opening into the vortex chamber between the two particle outlet openings.

Abstract: A process for preparing isocyanates in the gas phase, in which the mixing of the reactants and thus the reaction conditions are significantly improved by means of hydrodynamic measures such as increasing the turbulence of the feed stream in the central nozzle. As a consequence, the necessary residence time in the reactor and thus the length of the reactor are reduced and the formation of polymeric by-products which lead to caking in the reactor and a shortening of the operating period of the reactors is avoided.

Abstract: The invention relates to a method for producing hyper-pure, granular silicon by decomposing a gas containing silicon in a reactor consisting of a silicon carbide-based, carbon-fiber reinforced material; to a corresponding reactor; and to the use of said reactor for producing silicon.

Abstract: Isocyanates are produced in the gas phase in a manner such that temperature fluctuations over time and temperature distribution asymmetry are prevented. In this improved process, performance of the reaction in tubular reactors is accomplished by flow-related measures such as homogenization and centering of the educt streams. The formation of polymeric secondary products, which result in baked-on deposits in the reactor and a reduction in reactor service life, is consequently prevented.

Abstract: The present invention provides a process for quenching a gaseous reaction mixture during the phosgenation of diamines in the gas phase to produce diisocyanates. The gaseous reaction mixture contains at least a diisocyanate, phosgene and hydrogen chloride. The quenching liquid is injected into the gas mixture continuously flowing out of a cylindrical reaction zone into the downstream cylindrical quenching zone with the aid of at least two spray nozzles which are arranged at the entrance to the quenching zone at equal distances along the circumference of the quenching zone.

Abstract: The present invention relates to a method for producing highly pure, granular silicon with a narrow particle-size distribution by decomposing silanes or halosilanes in a fluidised bed and epitaxially growing silicon on silicon seed particles, which method is characterised in that the gas containing silicon is supplied to the reaction chamber in an upward flow and the contents of the fluidised bed are separated in a continuous or discontinuous manner, whereby a particle stream from the fluidised bed is supplied to a separator mounted outside the fluidised bed, particles of the desired size are separated and undersized particles are returned to the fluidised bed. The invention also relates to a device and the use thereof for carrying out said method.

Abstract: The present invention provides a process for quenching a gaseous reaction mixture during the phosgenation of diamines in the gas phase to produce diisocyanates. The gaseous reaction mixture contains at least a diisocyanate, phosgene and hydrogen chloride. The quenching liquid is injected into the gas mixture continuously flowing out of a cylindrical reaction zone into the downstream cylindrical quenching zone with the aid of at least two spray nozzles which are arranged at the entrance to the quenching zone at equal distances along the circumference of the quenching zone.

Abstract: The invention relates to a method for producing hyper-pure, granular silicon by decomposing a gas containing silicon in a reactor consisting of a silicon carbide-based, carbon-fiber reinforced material; to a corresponding reactor; and to the use of said reactor for producing silicon.

Abstract: A method for producing bisphenol A in prill form is disclosed. Molten bisphenol is top-fed into a prilling tower via a plate containing a plurality of nozzles. A gas coolant guided through a circuit is led into said tower in a counter flow direction. The prills are cooled to about room temperature, collected at the bottom of the tower and removed. Also disclosed is the device for carrying out the inventive method and the prills thus produced.

Abstract: Isocyanates are produced in the gas phase in a manner such that temperature fluctuations over time and temperature distribution asymmetry are prevented. In this improved process, performance of the reaction in tubular reactors is accomplished by flow-related measures such as homogenization and centering of the educt streams. The formation of polymeric secondary products, which result in baked-on deposits in the reactor and a reduction in reactor service life, is consequently prevented.

Abstract: The present invention relates to a process for the continuous discharge of pre-classified polymer particles, particularly rubber particles, from a gas phase polymerization reactor, comprising the steps of classifying the polymer in a classifier, discharging the particles with a sufficient size and conveying the undersized particles back into the gas phase polymerization reactor.

Abstract: The present invention relates to a process for the continuous discharge of pre-classified polymer particles, particularly rubber particles, from a gas phase polymerization reactor, comprising the steps of classifying the polymer in a classifier, discharging the particles with a sufficient size and conveying the undersized particles back into the gas phase polymerization reactor.

Abstract: The invention relates to a pump for discharging hot corrosive liquids, in particular molten salts, consisting of a pump pipe (1), a discharge pipe (2) dipping into the liquid and at least two valves (3, 4), whereby the liquid is discharged periodically by pressurisation.

Abstract: The process for producing crystallisation products with an average particle diameter of <1 .mu.m is based on the atomisation of a solution and the simultaneous evaporation of the solvent. The atomised solution A crystallises in a gas atmosphere, in which it is simultaneously contacted with a cloud of drops 4 of a surfactant-containing liquid B, thus forming an aerosol mixture A, B which is then deposited in the form of a colloidal crystal suspension in which the surfactant-containing liquid B forms the continuous phase. The cloud of drops 4 of the surfactant-containing liquid can also be produced by atomisation.

Abstract: The invention relates to an electrochemical half-cell (1) with a gas diffusion electrode (7) as cathode or anode wherein the gas chamber (6) is divided in particular into two or more gas pockets (6a, 6b, 6c) arranged one above another, the electrode chamber (2) of the half-cell (1) being divided into compartments (2a, 2b, 2c) which for the passage of the electrolyte (23), are connected to one another in cascade fashion via chutes (17), (18), (19).