Abstract: There is disclosed an improvement in the production of microfibers or fibrils of synthetic thermoplastic polymeric materials by flash-spinning solutions, emulsions or suspensions of the synthetic polymers in solvents, under the action of a high-speed jet of gaseous or vaporous fluid having an angular direction with respect to the solution, emulsion or suspension being flash-spun. The improvement consists in causing the fluid jet to expand through a nozzle (or duct) of the convergent-divergent type and in extruding the polymer solution, emulsion or dispersion under flash conditions at an angle towards the fluid jet in expansion in the divergent portion of the nozzle.

Abstract: Polymeric fibrids and paper-like structures produced therefrom are disclosed. These fibrids are produced by preparing an aqueous solution of a film forming polymer, injecting the solution into a liquid precipitating medium miscible with water but in which the polymer is insoluble, and providing sufficient shear to directly and rapidly precipitate the polymer to fibrid morphology. The fibrids, which are desirably first treated to render them more hydrophobic, may be formed into a web and dried utilizing conventional paper-making techniques to obtain the paper-like structures of the invention.

Abstract: There is provided a hard alloyed powder comprising:B--from 3 to 20% by weight,Al--less than 3% by weight,Si--less than 5% by weight,O--less than 2.5% by weight,at least one metal selected from the group consisting of Cr, Mo, W, Ti, V, Nb, Ta, Hf, Zr, Co and Ni, in the following amounts: Cr from 5 to 35% by weight, Mo from 1 to 35% by weight, W from 0.5 to 30% by weight and each of Ti, V, Nb, Ta, Hf, Zr, Co and Ni--less than 15% by weight, andthe balance being at least 10% by weight of Fe.A method for the production of said alloy powder is also provided and comprises atomizing molten alloy with water or inert gas in a specific manner.

Abstract: A non-woven cellulose ester fibrous filter sheet material comprising cellulose ester staple fibers and cellulose ester fibrets which exhibits improved filtration properties and the method of its preparation.

Abstract: Urea prills are obtained by contacting molten urea droplets with a co-current gas stream in a prill tower and cooling and collecting the prills thus formed in a fluidized bed having a second gas stream flowing countercurrent to the prills.

Abstract: A granulate consisting of smooth irregularly shaped granules is produced by preparing a molten bath of nickel and/or cobalt containing amounts of carbon and silicon which are correlated so that:8.03 C-4.42 C.sup.2 +7.23 Si>3.6pouring the molten alloy at a temperature 50.degree.-100.degree. C. above its liquidus temperature onto the surface of a pool of water which is agitated and maintained at 30.degree.-60.degree. C.

Abstract: A powdered metal filter composition and processes for producing the same by water atomization in which the composition exhibits an apparent density, compressibility and particle shape as a function of the composition chemistry and in particular the silicon, carbon and manganese content as well as the angle of intersection of the atomizing water jets; the composition providing an optimization of filtration efficiency, pressure drop across the filter pack, resistance to pressure deformation of the composition particles and the useful life of both the filter pack and the composition and the process producing such a composition with well-known apparatus and optimum yields of useful, particle-size fractions.

Abstract: Apparatus and method for cooling and collecting prills at the bottom of a prill tower including a fluidized prill bed and a rake rotatable therethrough.

Abstract: An apparatus for converting molten elemental sulphur into solid pellets is described. Droplets of molten sulphur are passed through a liquid cooling medium, preferably water, the medium being maintained at a temperature range wherein annealing of the sulphur will occur. The pellets thereby obtained are hard surfaced, resistant to crushing and have low water retention in storage. In one embodiment semi-molten droplets are flattened during passage through the cooling medium by engaging deflection plates so that less flowable and more economically storable pellets are obtained.

Abstract: Molten aluminous oxide abrasive, particularly molten mixtures of alumina and zirconia, are rapidly cooled and solidified by pouring into an agitated molten metal bath, having a boiling point above the temperature of said molten abrasive, such as molten tin, while being protected from oxidation. The solidified abrasive particles float to the top of the metal bath, are removed and separated from adhering metal, as by centrifuging, and crushed to abrasive grit-sized particles.

Abstract: A method and apparatus for producing metal powder in which a reducing liquid is introduced into the bottom of a substantially closed granulation chamber, and a reducing gaseous atmosphere is produced above the reducing liquid. A stream of molten metal is introduced into the top of the granulation chamber and is acted upon by one or more jets of a pressurized atomizing agent which atomizes the molten metal stream. Metal particles are cooled at least partly in the reducing gaseous atmosphere and are collected in the reducing liquid in the bottom of the chamber, from which they can be withdrawn.

Abstract: Aggregates having the amphora shape are produced by a process comprising dropping droplets of a slurry capable of being chemically gelled or solidified into a container containing a middle liquid phase capable of chemically gelling or solidifying the slurry, an upper liquid phase above the middle liquid phase and a lower liquid phase below the middle liquid phase, the components of the slurry exhibiting substantially no solubility in the upper and lower phases.

Abstract: Method of making lead shot by allowing droplets of molten lead to fall into a liquid quench bath and be thereby solidified. The droplets fall through a heating zone, particularly a flame of burning gas, into the quench bath. The apparatus to be used to practice the method preferably includes a container for molten lead comprising a generally V-shaped channel member having apertures in its base to permit molten lead to pass therethrough and exit as droplets.

Abstract: Method of making structural members from pliant, porous, solvent-free prepreg sheet comprising fusible resin microfibers and heat-resistant reinforcing fibers, which microfibers provide a lofty, clinging surface quality and fuse under heat and pressure to provide an essentially void-free matrix for the reinforcing fibers. Pieces of the novel prepreg sheet are conveniently molded under heat and pressure to provide laminated structural members.

Abstract: A method for making metal powder by atomizing molten metal is improved by causing the solidifying metal droplets to be subjected to a whirling flow of a powdery coolant such as a different powder, e.g. quartz sand or powder separated from the extracted flow of powder just made and cooled additionally. The whirling flow is sustained by blowing an inert gas in up direction into the powder collection chamber.

Abstract: Micron size polymer particles with narrow particle size distribution are prepared by dissolving the polymer in a suitable liquid solvent, impinging an atomized spray of the dissolved polymer on a moving film of a liquid in which the polymer is insoluble and then recovering the polymer particles from the resultant mixture of liquids.

Abstract: An apparatus for melt-spraying thermally sensitive material of low viscosity comprises a heatable multi-screw extruder having intermeshing, self-cleaning screws of specified clearance between the screws and between the screws and the extruder housing, a heatable pump for delivering molten material from the extruder to a heatable atomizer and a spray tank in which the atomizer is located for cooling and solidifying the melt-sprayed material.

Abstract: Fibrids are prepared by introducing a solution of a polymer into a liquid precipitation medium while exposing it to shearing forces. A poly(amide-imide) resin solution is admixed with a solvent which is miscible with the resin solvent but which is a non-solvent for the resin itself.

Abstract: Porous cellulose beads are prepared by distributing droplets of a solvent mixture containing a cellulose derivative into a precipitating solution to form porous beads which are then washed and hydrolyzed to form porous cellulose beads. The porous cellulose beads, which may be cross-linked, if desired, by suitable treatment, are useful carriers to which enzymes can be immobilized. The beads may also be used for the separation of enzymes, proteins, nucleic acids and the like, or to remove metal ions from dilute mining solutions.

Abstract: Sulphur pellets are produced by spraying molten sulphur from a vortex nozzle in the form of a downwardly diverging conical sheet or jet. The sulphur impacts on the surface of cooling water in a tank. The diverging nature of the jet and the resulting turbulent swirling action promotes the formation of pellets. Control of the size, surface texture, porosity and density of the pellets can be obtained for a vortex nozzle of any particular design by varying the supply pressure or pressure drop across the nozzle and the distance between the nozzle and the water surface.

Abstract: An apparatus is set forth wherein powder is produced by melting metal in a melting furnace where it is then poured into a tundish which directs the molten metal onto a spinning disc means. The tundish is located at the center of a nozzle plate which contains a plurality of annular nozzle means for directing a coolant flow downwardly around the spinning disc means at different radial positions. Controls are provided for controlling atmosphere in said apparatus. Further, controls are provided to control the speed of the disc means and the mass flow of the cooling fluid through each of the nozzle means.

Abstract: This invention comprises an improvement in a method for preparing ammonium nitrate prills wherein molten ammonium nitrate is prilled in a prill tower in the presence of cooling gas containing a predetermined amount of ammonia to retard thermal dissociation of the ammonium nitrate, thereby to decrease formation of extremely small aerosol particles of ammonium nitrate; the improvement comprises: (a) withdrawing cooling gas from an upper portion of the prill tower; (b) cooling and dehumidifying the withdrawn gas; and (c) recycling the cooled and dehumidified gas to a lower portion of the prill tower.

Abstract: In apparatus for treating and separating products in granular form, a container is provided with fluidization and vibration means, the grains and the pulverulent solid are subjected to the fluidization treatment only in a vertical portion of the bed, the circulation currents arising therefrom are utilized for separating, within the container itself, the treated product in granular form from the pulverulent solid, and the vibrations are utilized for discharging the treated products to the outside.

Abstract: A process of making glass beads which comprises the steps of forming a fluid medium comprising an aqueous liquid having glass-forming material therein at least most of which is dissolved in the aqueous liquid, forming drops of such fluid medium, and converting the drops to glass beads by causing the drops to travel in separated condition first through a firing zone at glass-forming temperature to cause evaporation of liquid and formation of glass from the glass-forming material, and then through a cooling zone to cause the glass to solidify.

Abstract: Porous cellulose beads are prepared by distributing droplets of a solvent mixture containing a cellulose derivative into an aqueous solution to form porous beads which are then washed and hydrolyzed to form porous cellulose beads. The porous cellulose beads, which may be cross-linked, if desired, by suitable treatment, are useful carriers to which enzymes can be immobilized.

Abstract: Polymeric fibers are produced from a polymer-solvent solution without mechanical agitation means by supplying a polymer solution in a solvent to a radial-symmetrical mixing chamber and causing a rotary flow therein which subjects the polymer to shearing forces while, at the same time, adjusting the temperature of the polymer-solvent mix to just below the precipitation temperature of the polymer. Under these conditions a polymeric fiber precipitates which, after separation from the solvent, is useful in the preparation of paper and textile products.

Abstract: A process for forming an atomized stream of a sprayable substance in a conversion zone, which may be a drying zone or a congealing zone, and forming discrete particles of said stream in said zone. The present invention comprises intercepting the stream of atomized droplets with a fluent binder capable of agglomerating fines in the stream faclitating their collection.The invention is particularly described with reference to the spray drying of pigment particles.

Abstract: Disclosed herein is apparatus (1) for suspending hot sticky pellets discharged from a pelletizer into a swirling bath of liquid, (2) for transportation of the resulting slurry to a liquid and pellet separator in a manner which avoids agglomeration of the pellets, and (3) for recycling the liquid through the foregoing steps.

Abstract: A process for prilling molten materials, e.g. molten sulphur and molten fertilizer materials, in which molten droplets are prilled down a prilling tower into a countercurrent gas stream which carries drops of a volatilizable material which volatilizes on contact with the molten material and removes heat from the molten material so as to form solid skinned droplets. The solid-skinned droplets are collected, e.g. from a fluidized bed in the base of the prilling tower.

Abstract: Scavenger aerosol sprayed into first aerosol containing solute dissolved in olvent picks up solvent leaving behind solute as micro particles. Scavenger aerosol consists of a liquid which sequesters the solvent of the first aerosol from its solute by exhibiting a greater chemical affinity for the solvent than for the solute therein.

Abstract: A method of prilling material in a prilling tower having the usual means for discharging molten material at the upper end thereof in droplet form to fall freely downwardly therein whereby the droplets cool and solidify in spherical or spheroidal form. A manifold extends about the interior of the upper portion of the tower and directs a continuous spray of water against the interior wall of the tower to provide a falling film of water along such wall substantially entirely about the interior circumference of the prilling chamber to cool the chamber and thus hasten solidification of the material and also prevent deposit of the material on the tower wall.

Abstract: A process is described for the isolation, in a solid state, of polyimides particularly those prepared by interaction of a polyisocyanate and a polycarboxylic anhydride in an organic solvent. A solution of the polyimide is passed into water preferably in the form of droplets or as extruded thin strands. The droplets or strands can be chopped, ground or otherwise comminuted after solidification. The process is particularly applicable to the isolation of solvent-soluble polyimides prepared by reaction of benzophenone tetracarboxylic dianhydride with a mixture of methylenebis(phenyl isocyanate) and toluene diisocyanate.

Abstract: A process for the manufacture of fibrids of thermoplastics materials by extruding molten thermoplastics through dies and breaking up the extrudate into fibers by means of a liquid medium causing shear stresses within a small volume, to which end the extrudate is passed to a zone of high energy dissipation so that it is completely divided up into fibers of the desired size in a single pass.

Abstract: Solid waste material is disposed of and a portion thereof converted into valuable refractory prills by use of a reactor having a substantially vertical pyrolysis chamber, a refuse charging inlet and a combustible gas outlet in the upper region thereof and a molten refractory material outlet in the lower region thereof. The molten refractory material withdrawn from the chamber is prilled to form ceramic beads. Gas-feed means charges an oxygen-rich gas into the chamber under pressure at a plurality of vertically spaced points along the length thereof so as to produce combustion of the waste organic components and generate heat. The charge is controlled to maintain a plurality of different temperature zones along the length of the chamber so as to effect incomplete combustion of the waste organic component and form a combustible gas and an organic-free molten refractory material.

Abstract: A process and apparatus for the manufacture of fibers from fusible materials and particularly materials of low viscosity. The melt and gaseous flow medium is passed through a Laval-nozzle at a supersonic speed. The nozzle and speed are so selected as to cause an abrupt temperature drop in the flow medium within the nozzle which causes the melt to solidify into fibers.

Abstract: When prilling molten materials into a tower containing dust particles suspended or carried in a counter-current gas stream, the amount of dust picked up by the droplets of molten material as they pass down the tower can be reduced by the addition of up to 10% by weight of very fine particles having a primary particle size of less than 1 micrometer to the dust in the tower.

Abstract: Polymer fibers are made from a solution of polymer in solvent by subjecting the solution to shear forces in a confining space by introducing a gas stream into the space in a manner to create a rotary gas flow therein and to cool the solution to a temperature at which polymer precipitates from the solution in the form of fibers.

Abstract: Liquid slag passes from an overflow in a pressure vessel into an underlying collecting vessel where the liquid slag is transformed into solid granular material by quenching in a liquid coolant. A desired coolant level is maintained within the collecting vessel by control valves under a pressure above atmospheric pressure. Two slide valves in the bottom of the collecting vessel are opened to discharge the granular material after accumulating to a predetermined measured level which is below the liquid coolant in the collecting vessel. A discharge vessel, beneath the collecting vessel, receives the discharged granular material. The discharge vessel is filled with a liquid coolant under either atmospheric pressure or under the same elevated pressure as the pressure within the collecting vessel.

Abstract: A method for making granules from sprayed molten material falling through a tower in which a substantial amount of the rising cooling gas stream is withdrawn from the tower at a level below the top of the tower and is discharged to atmosphere. Only the remaining gas stream requires treatment to remove dust and other pollutants, resulting in a considerably lower energy consumption at the same environmental pollution compared with other processes and installations known.

Abstract: A prilled ammonium nitrate containing 2 to 5 percent by weight water obtained by prilling an aqueous solution of 93 to 98 percent by weight ammonium nitrate is dried by: lowering the drying temperature of the ammonium nitrate to a temperature less than the III--IV crystalline transition temperature of ammonium nitrate at least once when the water content of the prilled ammonium nitrate is 0.3 to 1.5 percent by weight in the drying step; further drying at a temperature higher than the III--IV transition temperature; and adding an anti-caking agent to the dried prilled ammonium nitrate. The dried, prilled ammonium nitrate obtained is useful as an ammonium nitrate fuel oil explosive.

Abstract: A method for producing a nonwoven fabric-like material by a melt blowing technique. Conventional melt blowing equipment is used to form a gas stream containing melt blown microfibers comprising generally discontinuous thermoplastic polymeric microfibers having an average fiber diameter of up to about 10 microns. A liquid, such as water, is sprayed into the gas stream to rapidly cool the fibers and the gas, thereby allowing the production of high quality product at production rates significantly higher than in conventional melt blowing technology. In the final integrated fibrous mat formed on the forming surface, the microfibers are held together by gross mechanical entanglement with each other.

Abstract: Apparatus is described for producing microspherical particles. Also described is a method for operating said apparatus. A droplet generator dispenses uniform spherical droplets into a gelling column which is sealed at both ends to prevent entry of air thereinto. A gelling liquid and a gelling gas are provided in the column, and a further gas, which is of a density lower than that of the gelling gas, is introduced to the region above the gelling gas. At the interface between the gelling gas and the further gas, the gases are withdrawn from the gelling column.

Abstract: Solid waste material is disposed of and a portion thereof converted into valuable refractory material within a reactor having a substantially vertical pyrolysis chamber, a refuse charging inlet and a combustible gas outlet in the upper region thereof and a molten refractory material outlet in the lower region thereof. Gas-feed means charges an oxygen-rich gas into the chamber under pressure at a plurality of vertically spaced points along the length thereof so as to produce combustion of the waste organic components and generate heat. The charge is controlled to maintain a plurality of different temperature zones along the length of the chamber so as to effect incomplete combustion of the waste organic component and form a combustible gas and an organic-free molten refractory material.

Abstract: Sintered micro-powder of tetrafluoroethylene polymer having an average particle size of 100 microns or less, a sphere factor of 1.2 or less, a specific gravity of 2.20 or less, and a weight loss on heating of 0.5 percent or less. The process for the preparation thereof comprising atomizing an aqueous dispersion containing 5 to 80 percent by weight of tetrafluoroethylene polymer particles having 0.05 to 0.5 micron average particle size into a gas at a temperature above the melting point of the tetrafluoroethylene polymer and recovering the sintered micro-powder.

Abstract: The invention relates to the prilling of molten materials, notably ammonium nitrate and/or urea, through prilling bores which have an epoxy resin internal surface. This surface enables a greater through-put to be obtained with ammonium nitrate and/or urea when compared to bare metal bores.

Abstract: Molten materials, notably molten fertilizers, are prilled into a tower up which flows a gas stream carrying or suspending dust particles some or all of which have been treated with a silicone. The silicone treatment reduces the amount of dust which is picked up by the molten material.

Abstract: Production of a homogeneous mixture of plastics materials in powder form by subjecting a molten inhomogeneous mixture of two or more plastics to a maximum shear velocity of from 10.sup.4 to 10.sup.8 sec.sup.-.sup.1 for from 10.sup..sup.-2 to 10.sup..sup.-6 seconds; the pulverulent mixtures obtained are used in rotary sintering and injection molding.

Abstract: Process for producing microspheres comprises immersing a lower portion of a generally vertical, sol-gel feed tube having a lower microsphere formation needle in an alcohol drying column, feeding sol-gel at a predetermined rate into the upper end of the feed tube, and vibrating the feed tube in a generally horizontal direction at a predetermined amplitude and frequency to produce microspheres from the formation needle of a uniform and predetermined size. An electromagnetic transducer drive for vibrating the feed tube is used in one illustrative embodiment of apparatus for practicing the invention, and an electric motor offset drive is used in another illustrative embodiment of such apparatus. A feed tube having multiple microsphere formation needles at its lower end can be used for producing microspheres in quantity.

Abstract: Urea is prilled by spraying urea droplets downwardly into a solidification zone where it is contacted with a substantially inert gas. Prills are directed into a collector by diverting their flow by directing a gas through a perforated, inverted cone or pyramid located at the bottom of and in communication with said zone.

Abstract: an improved process for the granulation or coating of hygroscopic or nonhygroscopic materials where melt is sprayed onto cascading granules of common or uncommon substrate in an enclosed vessel such as a rotary drum preferably with lifting flights which provide maximum mixing of the granules and the atmosphere enclosed in the unit and where heat given off by solidification of the melt is absorbed by evaporation of water which is atomized as an extremely fine mist into areas of the vessel which are not subtended by falling granules. Evaporation is effected without impingement of the mist on the granules or vessel internals. Air for evaporation is pulled through the vessel concurrent with the flow of granules and its moisture content is regulated below the critical humidity of the granules throughout the vessel.