Showing papers on "Mixing (process engineering) published in 1982"

Continuous production of metal alloy composites

Abstract: A process and apparatus for the continuous production of shaped aluminum alloy-particulate composites. The process comprises metering at a substantially constant ratio a particulate solid molten aluminum alloy containing at least 0.10% by weight of magnesium into a mixing station while continuously vigorously agitating to produce a homogeneous mixture, simultaneously discharging from the mixing station a homogeneous mixture of molten aluminum alloy and particulate solid, transferring the mixture to a forming station and shaping and solidifying the composite.

Coal-aqueous mixtures

Abstract: Coal-aqueous mixture having high solids content and excellent stability are provided by an improved process involving selective mixing and other conditions.

Plastics alloy compositions

Abstract: A plastics alloy for a bearing material comprising polyphenylene sulphide and polyether ether ketone. The alloy is formed by powder mixing, melt blending or solvent blending and applied to a metal backing either as a sheet, or in solution or in powder form. The alloy is heated and roll bonded to the backing.

Mobile concrete mixing apparatus

Abstract: A mobile concrete mixing apparatus comprising an aggregate storage bin and cement storage bin mounted on a mobile carrier in spaced relation, a water supply tank mounted on the carrier and in operable communication with a water discharge pipe disposed in the proximity of the cement storage bin, a conveyor apparatus movable beneath and between the aggregate storage bin and cement storage bin for moving materials therefrom for discharge into a mixing auger assembly, the aggregate storage bin containing premixed sand and rock materials for achieving a homogeneous moisture and temperature therebetween, the sand-rock mixture, cement mixture and water being mixed together prior to admission thereof into the mixing auger assembly, the auger assembly comprising a plurality of material moving stages and a plurality of mixing stages interposed therebetween to assure a homogeneous mixture for delivery from the mixing auger assembly, all of the operation of the concrete mixing apparatus being initiated by a single lever operation.

Chemical printing liquid method and system

Abstract: An improved method and system for properly supplying and mixing printing chemicals and liquid diluent and for supplying the resulting liquid is provided. The method and system feature the use of periodic or continuous monitoring of the ph and/or electrical conductivity level of the printing liquid in a mixing zone to regulate the flow of initial and make-up chemicals to the zone, so that the proper concentration of chemicals is maintained in the liquid. The liquid is at least periodically removed from the mixing zone and make-up diluent is at least periodically added to the mixing zone. The method can be successfully run on a batch, semi-continuous or continuous basis and the system employs an automatic electronic ph and/or electrical conductivity analyzer and signal generator to automatically control signal responsive pumps in the conduit line(s) from the chemical supply zone(s) to the mixing zone. Preferably, automatic liquid level regulating means are provided in the mixing zone, along with an annular drip tube, circulating pump, exit and return lines and the like. The system and method are simple, economical, durable and highly efficient for making up proper levels of printing liquids for offset printing and the like.

Jet mixing of fluids in tanks

Abstract: An experimental investigation was made of the mixing of liquids in a tank where the liquid jet was injected through a nozzle The mixing time was defined as the time required to reduce the concentration variation within 1% of the mixed mean value and was measured by an impulse response The circulation time was also obtained from the response curve It was found that in the circulation flow regime of mixing (Re>3 ×104) there exists an optimum nozzle depth for rapid mixing It ranges from the liquid surface level to three-quarters of the liquid depth when the liquid depth is equal to the tank diameter, and is the mid-depth of the liquid when the liquid depth is smaller than the tank diameter When the nozzle height is within one-fourth of the tank diameter, it is efficient for rapid mixing to tilt the nozzle upwards enough to prevent the formation of a wall jet, which induces circulations of small variance of circulation time

Fermentation process and apparatus

Abstract: A method for agitating and mixing a gas with a medium in a closed fermentation vessel comprising recirculating said medium through a venturi jet mixer whereby it is mixed with the gas under high shear conditions to form a mixture of gas saturated medium and a dispersion of small gas bubbles and projected the mixture in the fermentation vessel below the liquid surface level in a plume extending horizontally from the jet mixer, then rising vertically to the liquid surface.

Apparatus for the selective retorting of carbonaceous materials

Abstract: A staged retort is provided for the retorting of certain types of carbonaceous materials such as oil shale, coal or lignite, wherein the staged retort includes a number of separate retort chambers arranged in a modular configuration, with one retort chamber above the other, and mounted transversely within the staged retort. Each retort chamber is heated to a different temperature, and carbonaceous material is moved from a given retort chamber to a retort chamber having a higher temperature, whereby heavier fractions of liquid and/or gaseous hydrocarbons are formed as the carbonaceous materials undergo pyrolysis. Arrangements such as pressure regulating valves are provided to reduce mixing of the various fractions between the individual retort chambers to nearly zero, and conduits are provided to separately withdraw the hydrocarbon gases and/or liquids from each retort chamber. The carbonaceous material leaving the last retort where the final pyrolysis reactions occur, is routed to a combustion compartment wherein it is burned to produce heat used to heat the retort chambers. The staged retort also includes arrangements for heating a predetermined portion of the gases formed in the retort chambers, to mix the heated portion with a predetermined unheated portion to arrive at a controlled temperature, and then to inject this controlled temperature gas and/or any other substances into the retort chamber interiors to control the temperatures and/or the reaction therein so that each retort chamber can be maintained at the proper temperature and conditions chosen for pyrolysis therein.

Method and apparatus for producing a cellular food product

Abstract: A method and apparatus for producing a cellular chocolate product in which a supply of chocolate is heated to bring it to a molten state, a gas which is largely soluble in the chocolate is introduced into the molten chocolate under pressure, the molten chocolate is fed under pressure into a mixing device (19) having closely adjacent relatively movable parts, the mixing device is operated to disperse the gas uniformly, so that it is dissolved throughout the molten chocolate, the liquid chocolate is passed through a restricted orifice (24) to release the pressure suddenly to atmosphere, so that the dissolved gas forms gaseous bubbles in the chocolate and the liquid chocolate is solidified into a finally resulting chocolate product by cooling. The clearance between at least some of the closely adjacent relatively movable mixing parts of the mixing device is less than half the minimum transverse dimension of the orifice and preferably less than one quarter so that any pieces of re-cycled filler, such as biscuit, are thoroughly ground within the chocolate so that little or no blockage of the orifice occurs.

Energy efficient extruder screw

Abstract: Extruders are widely used to transform solid plastic materials into molten plastic materials. Because of the low thermal conductivity of plastic materials and the inefficient mixing of the plastic materials inside an extruder, the heat is not evenly distributed in the material being processed and some portion of the material emerges from the extruder with excessive heat. This invention discloses a new screw with a novel mixing section which promotes mixing of the hot, molten material with the cold, unmolten material inside the screw channel by its unique geometry, thereby improving the heat transfer from the hot, molten material to the cold, unmolten material and increasing the energy efficiency of the extruder.

Experimental studies of phase separation in reaction injection‐molded (RIM) polyurethanes

Abstract: Reaction injection molding or RIM is the high speed production of polymer parts directly from low viscosity reactants injected into a mold. In contrast to thermoplastic injection molding, where the part solidified upon cooling, in RIM the shape is set by fast (insitu) polymerization. The reaction leading to the formation of the polymer can be initiated by mixing or by heat transfer.1 For the mixing activated process two highly reactive monomers or pre-polymers, in stoichiometric ratios, are brought into intimate contact by impingement mixing. The thermally activated RIM materials, on the other hand, have to be initiated by an increase in monomer temperature.1

Conservation of momentum in a barrier oxidation ditch

Abstract: For use in an activated sludge process, dual-baffle aerators for both vertically mounted surface aerators and static mixer-aerators are disclosed. These devices substantially prevent back-mixing of freshly aerated liquor into aerator intakes and provide directional propulsion. By connecting two or more such devices to form a barrier across the channel of an oxidation ditch, homogeneous aeration is provided to the mixed liquor. Barriered pump/aerator assemblies utilizing directional mix jet aerators (eddy jet) are also described. These devices can also be combined with dual-baffle aerators to furnish both propulsion and a selected degree of homogeneous aeration in a barrier oxidation ditch. An adjustably apertured barriered pump assembly is additionally disclosed for providing a selected balance between homogeneous aeration and/or mixing and heterogeneous aeration and/or mixing. Gateways therein are opened sufficiently to conserve momentum in the translationally flowing liquor while preventing back-mixing of aerated liquor. Use of a draft-tube pump assembly in combination with a barrier is described for providing homogeneous aeration and/or mixing and without a barrier to provide heterogeneous aeration and/or mixing. In combination with a sufficiently extended draft tube, a water barrier is created that substantially prevents back-mixing.

Cationic bituminous emulsions

Abstract: Reaction products of polyamines with sulfonated oleic acid or sulfonated tall oil fatty acids are disclosed which give emulsions capable of producing cationic medium set mixing grade asphalt emulsions, as well as rapid set asphalt emulsions. Solventless asphalts as well as asphalts containing up to 15% by volume of a hydrocarbon oil can be used for emulsification.

Production of thermoplastic elastomer composition

Abstract: PURPOSE: To obtain an elastomer compsn. having good resistance to heat and weather, tensil characteristics, flexibility and resilience, by mixing a specified crosslinkable rubber, a decomposable plastic, a noncrosslinkable rubber and a mineral oil solftening agent together, and dynamically heat-treating the mixture. CONSTITUTION: A mixture consisting of 90W40pts.wt. peroxide-crosslinkable olefin copolymer rubber (A), 10W60pts.wt. peroxide-decomposable olefin plastic (the sum of components A and B being 100pts.wt.), 5W100pts.wt. peroxide-noncrosslinkable hydrocarbon rubber material (C) and 5W100pts.wt. mineral oil softening agent (D), is molten and kneaded in the presence of an org. peroxide. An example of said peroxide-crosslinkable olefin copolymer is an ethylene-propylene copolymer rubber. An example of said peroxide-decomposable olefin plastic is isotactic polypropylene. COPYRIGHT: (C)1982,JPO&Japio

Dilution analysis for unidirectional diffusers

Abstract: The paper discusses the mixing mechanics of submerged, multi-port diffusers used to discharge heated water from steam-electric power plants into shallow receiving waters. An analysis for co-flowing diffusers is presented. The analysis is compared with similar fluid flow situations and predicted dilutions are compared with available laboratory measurements. The behavior of a co-flowing diffuser is then contrasted with that of a tee diffuser. A semi-empirical theory is derived for the tee diffuser and is compared with available measurements.

Mixing of gaseous substances

Abstract: The apparatus comprises a distributor device having two inlets connectible to two sources for supplying the gases to be mixed and a plurality of outlets each of which is connected to a first end of a respective capillary tube. The distributor device is arranged to connect each capillary tube to one or other of the two supply sources so that mixtures of the two gases are formed in a mixing chamber into which the other ends of the capillary tubes open, the mixtures containing the two gases in proportions which differ according to a number of capillary tubes traversed by each gas. The apparatus includes control means for causing the sequential formation of mixtures containing different proportions of the two gases and the supply of these mixtures to an outlet from the apparatus.

Apparatus for dissolving soluble coffee

Abstract: Apparatus and method for making large volumes of hot coffee wherein soluble coffee (i.e. freeze-dried or other instant coffee) is mixed with a relatively small stream of cool or cold water and the resulting mixture is sucked into a relatively large stream of hot water by jet action. The dry soluble coffee in the form of powder, crystals or flakes is metered by an auger from the bottom of a hopper through a discharge nozzle and falls into a mixing bowl wherein the cool or cold water is flowing in the form of a vortex. The cool or cold water spirals down the sides of the bowl in the form of a water curtain which wets and sweeps the interior surface of the mixing chamber thereby preventing buildup of soluble coffee solids thereon and inside the mixing chamber. The resulting mixture is sucked or drawn by jet action from the bottom of the mixing bowl into a conduit in which a stream of hot water is flowing in sufficient velocity and volume to create suction in a connection between the bottom of the bowl and the hot water conduit. The suction prevents steam or hot moisture from rising in the mixing bowl and reaching the dry instant coffee in the hopper or discharge nozzle. An easily detachable and replaceable nozzle cap for the projecting end of the auger facilitates quick and easy access to the auger and discharge nozzle, not only for periodic routine cleaning when the apparatus is empty but also when the apparatus has sat idle for several days in a humid atmosphere with soluble coffee solids in the hopper and discharge nozzle.

Method of cooling product gases of incomplete combustion containing ash and char which pass through a viscous, sticky phase

Abstract: Hot gases containing ash and char which pass through an undesirable viscous, sticky phase on cooling through an intermediate temperature range, are cooled in a first cooling zone including a falling film of cooling liquid and a spray of cooling liquid followed by contact with a body of cooling liquid and subsequent mixing therewith.

Influence of drag reducing additives on the structure of turbulence in a mixing layer

Abstract: The structure of a free turbulent mixing layer in Newtonian and drag reducing fluids is discussed using results from visualization and LDA-techniques. Particular emphasis is placed on results for the turbulent shear stress and the time correlation function.

Automatic animal feeder

Abstract: An automatic animal feeder has a motor driven auger for supplying milk powder from a storage hopper to a mixing vessel. The mixing vessel has outlets for the continuous supply of liquid feed mixture to animal feeding locations. An electrical pump supplies water from a storage tank in the feeder to the mixing vessel. The auger and the pump are connected to an electrical control unit for delivering powder and water to the mixing vesel simultaneously in batches, the batches being automatically timed to provide a required powder to liquid ratio according to the setting of concentration selector switches on the front panel of the feeder. The batches of powder and water are supplied to the mixing vessel together in pairs when the liquid feed mixture is below a level determined by a sensor in the mixing vesel. Calibration of the powder supply is carried out by weighing a sample batch dispensed during a fixed calibration period and setting the measured weight on a calibration dial on the front panel. A heater is provided in the storage tank for heating the water prior to supplying it to the mixing vessel. If the temperature of the water is outside a predetermined range, the supply of both water and powder is disabled.

Process for recovery of high purity silicon

Abstract: A method of recovering silicon from an aqueous slurry containing finely divided silicon particles comprising mixing at least one flocculating agent with the slurry, allowing silicon flocs to form and physically separating the silicon flocs from the slurry for re-use of the silicon contained therein.

Process for producing fiber-reinforced metal composite material

Abstract: The invention provides a process for producing a fiber-reinforced metal composite material which involves mixing inorganic fibers with an aluminum alloy at a temperature at or above the melting point of the alloy. A composite material of improved physical properties is then produced by either of the two following alternative procedures. In a first procedure the composite is removed from the mold at a temperature that is not higher than the solid phase line of the alloy (i.e., the temperature at which a liquid phase appears in the alloy). The composite is then heated to a temperature above the solid phase line and the elevated temperature is held for a definite period of time (heat treat-ment). In a second procedure the composite is quenched to a temperature of 200°C or lower from a temperature above the solid phase line but below the melting temperature. This quenching is done quickly before allowing the composite to cool to a temperature that is not higher than the solid phase line.

Process for treating pressure-sensitive hot melt plastics produced in mixing units

Abstract: In a process for treating pressure-sensitive hot melt plastics produced in mixing units, subsequently extruded and provided with a protective layer, preferably hot-melt adhesives, to create a product which can be handled well and is suitable for further processing by melting in a special way and to reduce decisively the thermal loading in the production operation and the processing operation, a strand of any desired length is produced, sheathed with a film and, for processing, is melted together with the film.

High pressure impingement mixing apparatus

Abstract: Apparatus for high pressure impingement mixing includes a mixing chamber and aftermixer chamber located on opposite sides of, and perpendicular to, a transfer dispense chamber. Two or more reactive components are injected into the mixing chamber. The resultant mixture is directed across the transfer dispense chamber into the aftermixer chamber, and from the aftermixer chamber back into the transfer dispense chamber and around the crossing mixture to the outlet of the transfer dispense mixer for dispensing. Each chamber includes a plunger which is actuated sequentially to interrupt mixing and clean the respective chamber. The device provides effective and intimate mixing of the reactive components and dispenses a stable emulsion so that the device can be used in applications presently suitable only for low pressure mixing devices. It may also be used in existing high pressure applications but without the need for conventional aftermixer devices and gating systems disposed in the forming molds.

Device for diluting liquid sample

Abstract: The disclosed device for diluting liquid sample feeds both the liquid sample and a diluent solution to a mixing point through a first and a second roller pumps respectively, so that the concentration of the liquid sample in the resultant mixture is controlled by regulating the revolving speeds of the first and second roller pumps.

Apparatus for mixing and distributing solid particulate material

Abstract: An apparatus and method for mixing and distributing solid material in which the material is continuously introduced into a vessel and a pressurized gas is introduced into the lower portion of the vessel at a velocity sufficient to pass upwardly through the material in the vessel to promote mixing of the material. A plurality of outlets are disposed in an angularly spaced relation along the vessel for permitting the material to continuously discharge to a plurality of selected locations. The excess gas in the vessel is removed, cleaned and introduced back into the vessel.

Freeze blending of reactive liquids and solids

Abstract: Chemically reactive liquids such as catalyzed monomers and prepolymers are mixed with finely divided solids to form a homogeneous blend by chilling the liquid to a temperature below its solidification point, forming it into finely divided solidly frozen particulates, chilling the finely divided solids to a temperature below the solidification temperature of the reactive liquid and mixing the materials together without allowing the temperature to rise to the liquid solidification point. The admixture may then be formed into a permanent shape by warming to a temperature whereat the frozen liquid melts and the liquid is caused to react.

Process and gravity feed mixer for mixing bulk materials in a container

Abstract: The gravity feed mixing of bulk materials is effected by removing partial quantities of the material at each of a plurality of vertically disposed levels, and passing the removed material through a series of funnels arranged vertically so that the material is admixed with the material passing from a higher level and fed to a lower level.