Showing papers on "Mixing (process engineering) published in 1981"

Collection efficiency of cyclone separators

Abstract: Based on terLinden's (A. J. terLinden, “Investigations into Cyclone Dust Collectors,” IME Proc., 160, 233, 1949) experimental observations, a three-region model is proposed for the fluid flow in a cyclone. Within each region, turbulence is assumed to promote mixing of the suspended particles. Incorporation of this mixing concept into the three-region model allows an analytic expression for the collection efficiency of the cyclone to be developed. The theoretical result is compared with data obtained in the high temperature, high pressure exhaust from a pressurized fluidized bed combustor.

Apparatus to cool particulate matter for grinding

Abstract: In an insulated mixing and cooling chamber having a feed auger to deliver cooled particles to a grinder and an intromitter auger rotatable around the feed auger to mix the particles within the chamber, independent variable speed, reversible motors operate the intromitter and feed augers, whereby the relative rotation of the augers may be precisely adjusted even while the mixing apparatus and associated grinding apparatus are operating. Electronic and or pneumatic control of cryogenic liquid inflow, as well as electronic control of the auger drive motors, may be used to optimize cooling and mixing conditions.

Method and apparatus for continuous feeding, mixing and blending

Abstract: Apparatus and method for automatically and continuously feeding, blending and mixing particulate material. In a non-mixing mode, a primary material is gravity fed through a vertical flow tube disposed in a chamber. Material flows into the chamber until an equilibrium level is established within the chamber. The volume of material fed through the system is governed by the through-put of a take-off screw, which communicates with a port in the bottom of the chamber. In a mixing mode, secondary materials, such as additives, are metered into the chamber at a point above the equilibrium mixing level, which secondary materials are mixed with the primary material, thereby automatically proportioning the final product feed. The vertical flow tube can be rotatable about its longitudinal axis in either mode to enhance mixing and feeding.

Modular mixing apparatus including interchangeable fluid processing means

Abstract: A helically moving fluid body leaving an extruder screw and brought into contact with rotating shearing means, undergoes laminar displacement, is then guided through a stationary sleeve along undulating linear paths of travel of relatively short axial length, and thereafter undergoes further laminar displacement and discharges into a die. During movement of the fluid mixture along the undulating linear paths of travel subdivision and blending of substantially all of the material in the fluid body, which is not in a fluid state, takes place. Thereupon the blended mixture is advanced to a die member at a desired fluidity and temperature in response to die requirements. Heating of the barrel is significantly reduced and energy conservation of an appreciable nature is achieved. In carrying out mixing as noted above there is employed a modular mixing apparatus constructed with multiple processing means suitable for shearing, kneading, flow diverting, dispersing, blending and the like. The multiple processing means includes a basic component assembly with which other components may be employed interchangeably to deal with varying types of fluid or plastic bodies wherein solid material may be present.

Method for producing a cordierite body

Abstract: A method for producing a cordierite body having isotropic coefficient of thermal expansion comprises the steps of preparing a batch by mixing and kneading particles of fired talc, alumina supplying substance such as alumina and aluminum hydroxide, and silica supplying substance such as silica and kaoline, anisostatically forming the batch and drying and firing the obtained formed body.

Model for pulverized coal-fired reactors

Abstract: An axisymmetric, elliptic model has been developed for analysis of confined, turbulent, coal-laden diffusion flames. The scheme is Eulerian for gases and Lagrangian for particles. The approach emphasizes the turbulent fluid mechanics of the mixing-limited gas phase reaction processes. The two-equation (k−∈) turbulence model is used for closure. Particle drag and turbulent particle diffusion are also modeled. Gaseous combustion is modeled with a probability density function for the mixture fraction. Fluctuations in mixing of inlet streams and coal off-gas are considered. Coal pyrolysis and oxidation reaction processes are assumed to be slow with respect to the turbulent time scale. Particle and gas radiation are incorporated by a flux method. Predictions emphasize the importance of turbulent particle dispersion.

Solid electrolyte for use in oxygen concentration sensor

Abstract: A solid electrolyte for an oxygen concentration sensor is provided by mixing ZrO2 and about 7.5 to 8.5% by mol of a stabilizer such as Y2 O3, grinding the mixture to have a BET specific surface are of about 9 to 20 m2 /g, adding to the ground mixture a forming aid, forming the mixture into a predetermined configuration and firing the formed mixture at about 1420° to 1520° C. The electrolyte has a surface-average grain size of about 5 microns or less and a structure of a cubic phase alone at the surface thereof and even in a finely ground state.

Gas absorption in aerated mixing vessels with non-newtonian liquid

Abstract: Aerated mixing vessels are often used in chemical and biological industries. When the rate of gas absorption controls the rate of reactions, kLa is used as the design standard. It was previously reported by the present authors that the overall vessel condition varied from bubbling-controlling condition at relatively high gas rates to agitation-controlling condition at relatively high impeller speeds via intermediate condition. According to this two-region model, kLa for the airwater system in the aerated mixing vessel has been correlated well in a wide range of operational conditions. In this report, the two-region model is applied to Newtonian liquids with various physical properties and to non-Newtonian liquids, and reasonable dimensionless correlative equations are obtained.

Apparatus for manufacturing cellulosic fibrous material which can be pressed into molded parts

Abstract: An apparatus for manufacturing cellulosic fibrous material suitable for future compressing into a molded article which comprises a prepulverizing apparatus for cutting cellulosic material, a mixing chamber for mixing the prepulverized cellulosic material with a bonding material, a forming head for receiving the mixture from the mixing chamber and for dispensing the cellulosic fibrous material/binder mixture as a mat upon a moving carrier, a heating apparatus for heating the mat and a pressing apparatus for compacting and bonding the heated fibers in the mat.

Manufacture of bread crumb-like product

Abstract: Farinaceous product particles having properties comparable to those of bread crumbs are formed by continuously mixing the components with gaseous leavening in a plug flow mixer, extruding dough from the mixer; cutting the extruded dough into particles, heating the dough particles to surface dry the particles and stabilize the shape; and subsequently drying them to the desired moisture level. The dried particles are comminuted to the desired crumb size.

Turbine engine with combustor premix system

Abstract: A turbine engine having a combustor premix system for mixing fuel and air to provide increased efficiency by reducing temperature peaks in the combustor. The system includes a primary mixing chamber for mixing compressed air and atomized fuel and a secondary mixing chamber located between the primary mixing chamber and the combustor for mixing additional compressed air to the fuel-air mixture. The secondary mixing chamber comprises a plurality of tubes with air metering ports in the walls thereof and a control assembly to vary the air flow to the ports for off design engine operating conditions, and optimizes fuel-air mixtures for the combustor at all engine operating speeds improving fuel economy and exhaust pollution control. The primary mixing chamber is located adjacent to and between the compressor for the air and the combustor so that the fuel-air mixture flowing therethrough tends to cool the compressor and the chamber itself shields the compressor from radiant heat from the combustor.

Mixing method and apparatus utilizing pipe elbows

Abstract: A mixing apparatus and associated method comprising a system for supplying a first substance of liquid constitution and a system for supplying a second substance to an assembly of pipe elbows to effect mixing and transport of the substances along the assembly. The pipe elbows are right angle elbows connected one after the other in groups of three. Each group has an inlet and an outlet disposed in parallel planes and axially offset from one another. The pipe elbows in each group have center lines disposed in mutually perpendicular planes to cause the mixture to rotate as it travels along the pipe elbows.

Injector mixer apparatus

Abstract: An apparatus and process for uniformly mixing a relatively small amount of material with a relatively large amount of another material in particulate form by introducing the smaller amount of material via a pipe within another concentric pipe through which a high pressure gas is introduced which thereby provides a zone of turbulence into which a particulate material in larger amounts is introduced, the mixture of gas and materials being transported through a treatment chamber to produce a uniform mixture.

Solids mixing in a fluidized bed with horizontal tubes

Abstract: A model of solids mixing in a fluidized bed containing horizontal tubes is developed from new data on mixing of magnetic tracer in a 1.2 x 1.2 m square fluidized bed of 700-..mu..m particles of silica sand. In the model the dense phase consists of an upward moving drift phase and two downflowing phases, the one at the vessel wall parallel with the tubes moving faster than the other. Solids can exchange between the phases. Of the nine parameters appearing in the governing difference-differential equations four have dominant influence on the concentration histories: the velocities of the down-flowing phases, the solids exchange coefficient, and the volumetric fraction of the drift phase. The model interpretation of the mixing data at gas velocities less than 1 m/s revealed low circulation of solids and high solids exchange rate for the drift phase, both relevant for the heat and gas mass transfer rates in the bed. 26 refs.

Process for the production of a low density activated alumina formed product

Abstract: An improved process for the production of a low density formed product of an activated alumina having a large macro-pore volume and an excellent abrasion resistance, which comprises mixing the starting solid material selected from an alumina powder being able to be re-hydrated and a mixture of the alumina and other solid material with water, said starting solid material having an average particle size of 1 micron to 35 micron and a quarter deviation of particle distribution of not more than about 1.5, forming the mixture of a solid material and water into various shapes, re-hydrating the formed product by keeping it under wetted atmosphere or in water, and calcining the resulting re-hydrated product.

Mixing apparatus for cementitious materials

Abstract: An apparatus for mixing a cementitious material, such as those quick-setting cementitious materials utilizing a volatile liquid, has a solid frame as the top of a mixing chamber. An inlet end of the solid frame is pivotably mounted on a vehicle. An auger or mixing screw is mounted in the frame, the auger being removable from the frame due to the mounting of one bearing in a removable plate member and the provision of a releasable flexible coupling between this end of the auger shaft and the drive motor. A low pressure gas may be inserted into the housing of the other bearing to prevent seepage of liquid or fumes into that bearing. A removable elastomeric trough forms the bottom of the mixing chamber and contains a discharge opening. A substantially dry material is inserted into the mixing chamber through an inlet hopper and a liquid injection arrangement introduces a liquid into the mixing chamber. The liquid injection arrangement extends along a length of the auger and is spaced from the inlet hopper, so that the substantially dry material forms a plug to prevent the liquid or fumes from backing up the inlet hopper.

Inexpensive method of recovering condensable vapors with a liquified inert gas

Abstract: Method and apparatus for recovering, as liquid, condensable vapor contained in a gas stream by refrigerating the gas stream by injecting the liquified phase of an inert gas, such as nitrogen, mixing the combined gas stream and liquified inert has, and separating the condensed condensable vapor from the remaining gas stream and inert gas.

Local heating system using solar, geothermal and heat pump sources - has heating water storage and domestic hot water storage heated by coil heat exchangers supplied with heated fluid

Abstract: The local heating system is partic. applicable to groups of domestic dwellings and comprises: a reservoir (1) of hot water for heating usage which is circulated through a heating circuit (2,3) by a circulation pump (5) and a solar energy collector (10) supplying a circuit (8,9) with a heat exchanger (7) in the reservoir (1). A heat pump (16) supplies a circuit (14,15) with a heat exchanger (13) in the reservoir (1). A geothermal energy collector (17) supplies the input circuit (18,19) to the heat pump. Each circuit has a pump and control valves incorporated. The heating circuit (2,4) has a mixing valve (4) to mix some of the return water in the heater inlet when the temp. in the heating circuit exceeds a set value. A source of hot water for domestic hot water is also incorporated (30,31,32) and is driven off the solar, geothermal and heat pump heat sources.

Methods for storage of guayule plant material

Abstract: A method of storing guayule and guayule-like plant material prior to processing which comprises mixing the material in communited form with at least one essentially water-free organic liquid to form a slurry in which the material is protected from contact with oxygen and storing said slurry for at least about 24 hours is discosed. Preferably, the organic liquid is an alcohol, ether, ester, ketone, or hydrocarbon and optionally the slurry also contains an oxidation stabilizer.

Removal of solids from a wet oxidation reactor

Abstract: An apparatus for spontaneous wet oxidizing of waste water with the addn of O is composed of mixing area(A), heat exchanger(X), oxidation reactor(Y) and cooler(Z) The sludge which is mixed with O, is heated at X and is oxidized at Y The oxidized sludge and vapor phase reactants is cooled at Z and flowed out through F, while the solids which is accumulated at the buttom of Y is removed with water from J

Method and apparatus for mixing solids with liquids, in particular for gluing wood chips

Abstract: A system for mixing of wood chips or the like with glue which involves an intensive movement of the chips during the addition of the glue and a subsequent thorough mixing of the glue and the chips in a ring of material to be mixed, is characterized by steadily accelerating the chips out of an axial motion via a centrifugal and helical motion and by the addition of the glue during this acceleration, the acceleration to the velocity of the ring of material to be mixed taking place only following the addition of the liquid.

Combustion burner apparatus

Abstract: A burner device adapted for use in a particulate filter arranged in an exhaust system in a diesel engine for incinerating particles collected by the filter. The device includes a mixing chamber for mixing the fuel and the air, the chamber has nozzles for generating flows of the mixture directed to the combustion chamber. Means are provided for pre-heating the air introduced into the mixing chamber. A trapping vaporizer is provided for improving the vaporization of the fuel in the mixing chamber.

Extrusion apparatus for the production of foamed synthetic material

Abstract: In the production of foamed thermoplastic synthetic material, synthetic material is melted in a screw extruder and fluid propellant is injected into the molten sythetic material. The residence time of the molten mixture has a determining effect in regard to uniform distribution of the propellant and thus also in regard to the uniformity of the cell structure. In order to provide for homogeneous mixing of the propellant and uniform cooling of the molten mixture, without using an excessively long screw extruder, the screw extruder is provided, downstream of a melting region thereof and of an injection opening thereof through which propellant is introduced, with flow obstruction structure which is by-passed by static mixing structure disposed outside the screw extruder. The molten synthetic material is simultaneously mixed with the propellant and cooled in the static mixing structure.

Process for blending coal with water immiscible liquid

Abstract: A continuous process for blending coal with a water immiscible liquid produces a uniform, pumpable slurry. Pulverized raw feed coal and preferably a coal derived, water immiscible liquid are continuously fed to a blending zone (12 and 18) in which coal particles and liquid are intimately admixed and advanced in substantially plug flow to form a first slurry. The first slurry is withdrawn from the blending zone (12 and 18) and fed to a mixing zone (24) where it is mixed with a hot slurry to form the pumpable slurry. A portion of the pumpable slurry is continuously recycled to the blending zone (12 and 18) for mixing with the feed coal.

Apparatus for mixing and dispensing liquid resins

Abstract: An apparatus for mixing and dispensing liquid resins which comprises a mixing unit which is a stationary mixer and a dispersing unit which comprises a dispersing plate placed crossing the line of flow head of the stationary mixer and which has at least one perforation for allowing the materials to be mixed to pass therethrough, a first material supply tube having at least one perforation at the end thereof and which is stuck to the front surface of the dispersing plate for allowing a first material to pass therethrough and a second material supply tube which encloses the first material supply tube and conveys the second material. The structure is effective to cause a time-wise mixing function, because a delay or a time-wise deviation is given to the flow speed of a limited portion of the materials to be mixed, resultantly preventing such a defective mixing function as is caused by a potential discrepancy in commencement time of supply of all the materials to be mixed, from occurring.

Process for treating cat cracker bottoms sludge

Abstract: A process is disclosed for treating cat cracker bottoms sludge to remove the cat cracker bottoms hydrocarbons from the catalyst fines in the sludge to provide treated fines which are environmentally safe for landfill. The process involves mixing the sludge with a hydrocarbon diluent, separating the fines from the diluent-sludge mixture, then mixing the separated fines and remaining diluent with water and distilling off the remaining diluent to obtain the treated fines.

Preparation process of thermoplastic moulding masses

Abstract: 1. A process for the production of a moulding composition from 10 to 95 parts by weight of a linear saturated polyester, and 90 to 5 parts by weight of an elastomeric graft copolymer, with or without conventional additives, by mixing the components in the melt in a mixing apparatus having a plurality of feed zones and at least one devolatilizing zone arranged downstream of a mixing zone, wherein the graft copolymer having a water content of from 5 to 50% by weight, and the polyester melt are introduced into different zones of the mixing apparatus.

Fluid mixing technique

Abstract: One non-propelled fluid resident in a reservoir is sucked into the flow path of a further fluid in transit propelled by fluid pressure. This is achieved by means of inducing a spiral cyclone path flow pattern in the propelled fluid to create a converging vortex with a turbulent mixing zone into a linear output transit line. The pressure at the vortex zone is reduced significantly from atmospheric to thereby produce a strong suction propellant force bringing the stored fluid into the turbulence mixing zone. The stored fluid is introduced axially in line with the cyclone axis and linear output transit line which receives thoroughly mixed fluids in substantially constant proportions over significant changes in pressure of the propelled fluid. Thus, the mixer device is ideal for dispensing insectides with a garden hose, detergents into a dishwasher, chlorine into a swimming pool, etc. One embodiment therefore provides for a rotary fluid driven turbine with a rotary spray head as a medium for inducing the cyclone shaped spiral flow path with converging vortex and simultaneously spraying the mixed fluids.