Abstract:
Eine Misch- und Dosiervorrichtung zum Mischen und Dosieren von flüssigen Chemikalien umfasst eine Kreislaufpumpe (2) mit einem Saugstutzen und einem Druckstutzen, eine Rohrschlange (12), deren Volumeninhalt so bemessen ist, dass die in die Vorrichtung eindosierten Chemikalien eine für die chemische Umsetzung ausreichende Verweilzeit haben, ein Staurohr (18), das den aus der Rohrschlange (12) austretenden Kreislaufstrom unter Bildung einer Staustelle von dem Auslass der Rohrschlage zu einer Dosierleitung (40) führt, die zwischen dem Staurohr (18) und dem Saugstutzen der Kreislaufpumpe (2) angeordnet ist und wenigsten zwei Dosierventile (50, 52) umfasst, sowie ein Fallrohr (28), das mit dem Staurohr (18) verbunden ist und einen Vakuumfiansch (36) zum Anschluss der Misch- und Dosiervorrichtung an eine Vakuumvorrichtung aufweist.
Abstract:
A tubular reactor for use in polymerisation reactions is described, having a design pressure P R of 40-65 barg, at least a portion of which is oriented vertically and at least part of which vertical portion is surrounded by a concentric jacket for the passage of cooling fluid, wherein the design pressure in barg of the jacket P J is less than 0.0018.P R 225 . Another aspect of the invention concerns a tubular reactor for use in polymerisation reactions having a design pressure P R of 40-65 barg, at least a portion of which is oriented vertically and at least part of which vertical portion is surrounded by a concentric jacket for the passage of cooling fluid, wherein the actual thickness of the reactor wall is either no more than 2mm greater and/or no more than 10% greater than the minimum wall thickness required to withstand the design pressure P R as calculated according to the ASME Boiler and Pressure Vessel code.
Abstract:
Systems and processes for rapidly depressurizing a reactor system are disclosed. The systems and processes are particularly useful in the high pressure polymerization of ethylene.
Abstract:
The invention relates to a method and apparatus for safely producing hydrogen peroxide by injecting dispersed minute bubbles of hydrogen and oxygen into a rapidly flowing liquid medium. The minute bubbles are surrounded by the liquid medium of sufficient volume for preventing an explosive reaction between the hydrogen and oxygen. The liquid medium is formed of an acidic aqueous solution and a Group VIII metal catalyst. Hydrogen is sparged into the flowing medium for dissolution of the hydrogen in the medium. Oxygen bubbles are reacted with the dissolved hydrogen for producing hydrogen peroxide. Preferably, the liquid medium has a velocity of at least 10 feet per second for providing a bubbly flow regime in the reactor. The invention allows the direct combination of oxygen and hydrogen while preventing propagation of an explosive condition within the reactor. The method and apparatus provide for the safe production of hydrogen peroxide with low manufacturing costs.
Abstract:
A mixing and metering device for mixing and metering liquid chemicals comprises a circulation pump having a suction port and a pressure port, a pipe coil, the contents volume of which is dimensioned such that the chemicals metered into the device have a residence time sufficient for the chemical reaction, a choke tube which guides the circulation stream exiting from the pipe coil, with formation of a choke point, from the outlet of the pipe coil to a metering conduit which is arranged between the choke tube and the suction port of the circulation pump and at least two metering valves, and also a falling tube which is connected to the choke tube and has a vacuum flange of the mixing and metering device to a vacuum device.
Abstract:
Systems and methods for heating, reacting, and/or treating a stream containing oxidizable matter. Recycle reactor is used alone or in conjunction with plug-flow reactor. Density differences in the recycle reactor facilitate flow within the recycle reactor without substantial external heat exchange.
Abstract:
In forming an electrophoretic gel, various defects can be induced by the shrinkage that generally accompanies polymerization. These defects can include pulling away from a vessel wall or voids or bubbles forming within the gel itself. Prior to polymerization, a monomer can be compressed to a density at least equal to that of the expected density of the final gel, which then is substantially free of such shrinkage defects. The disclosed method is readily generalizable to other situations to produce polymers substantially free of defects due to shrinkage.
Abstract:
An apparatus used in the pretreatment of wood chips in a process for converting biomass to a liquid hydrocarbonaceous fuel. The apparatus functions to break down the wood chips to a size distribution that can be readily handled in a slurry form. Low maintenance operation is obtained by hydrolyzing the chips in a pressure vessel having no moving parts.
Abstract:
A gas flow control system in which several constituent gases are mixed and the mixture delivered through controlled injectors to a processing zone. Mass flow controllers control the injector flows with one of the controllers being a master and the other being slaved to provide a selected percentage of the flow through the master controller. The gas mix is regulated by a mass flow controller on one of the constituents and a flow meter on the other, the flow meter producing an error signal which is used to readjust the total flow through the injectors by control of the master injector flow controller.
Abstract:
A device for treating urea solutions coming from synthesis reactors and containing in addition to the formed urea also free ammonia, water and unreacted ammonium carbamate having two steps wherein in the first step, a substantial amount of ammonia is distilled while ammonium carbamate is only partially decomposed, and in the second step, the bulk of carbamate is decomposed and the residual ammonia is distilled.