Abstract: A centrifugal classifier is disclosed which has a higher throughput than existing classifiers. The classifier has a substantially cylindrical upright housing with an approximately tangential sifting-air inlet in which are arranged at a radial distance from, and centrally of, the casing of the housing, a vane-ring and, at a radial distance inwardly therefrom, a sifting rotor with a lamination-ring forming radial passages, an inlet for the granular material to be classified opening, at the top, into the classifying area located between the vane-ring and sifting rotor, and an outlet for the sifting air, charged with fine material, being located adjacent the rotor, the diameter of the outlet corresponding approximately to the inside diameter of the rotor, and the sifting-air inlet and the vane-ring extending over approximately the same axial length as the rotor, characterized in that the two end-faces of the sifting rotor are each located adjacent a fine-material/sifting-air outlet.

Abstract: Apparatus for supporting screen (12) in a screening machine (10) that will permit long-life of the screen even when subjected to heat and vibration. The screen or wire cloth edge is folded over (30) and fastened or joined (42, 44, 46), with a metal rod (32) inserted down through the foldover space (34). Spring clips (40) or other adjustable tensioning devices attach the steel rod (32) to the screening machine frame (50), thus placing the screen (12) in tension.

Abstract: A special form of fluid cyclone in which the velocity energy in the exit fluid is converted into exit pressure thus permitting the device to discharge to atmospheric pressure or a higher pressure while a vacuum may exit in the central core of the vortex. The result is achieved by use of a curved passage at the exit which starts as a coaxial space and gradually expands and turns outward to become a circular space between two disks. The removal of reject material to atmospheric pressure with a vacuum at the core may be achieved by limiting the restriction in cross-section of the bottom core such that the pressure is atmospheric and allow it to leave through a space between the end of the cone and a blunt shaped surface.

Abstract: A process is disclosed which removes gangue minerals from phosphate rock by forming an aqueous slurry of phosphate rock and its impurities, then using a low boiling, nonpolar, water insoluble, bridging hydrocarbon to selectively agglomerate the phosphates.

Abstract: A method is disclosed for the production of metallurgical grade coal and low ash coal by the combination of froth flotation and selective agglomeration.

Abstract: Method and apparatus 10 permits material immersed in a body of fluid to move under the influence of gravity across inclined surfaces 14 and 24 having an angle of incline below the horizontal approximately equivalent to that of the repose angles .alpha. and .beta. of the fluid-immersed material. Such materials are moved under the influence of gravity rather than fluid forces to winnowing channels 25 comprising closed regions of finite length through which an upwelling flow of fluid at relatively high velocity passes into the fluid body in which the material is immersed. Undesired materials pass upward, borne on the upwelling flow through the fluid body while desired materials 36 move through winnowing channels 25 counter to the upwelling flow, passing along surface 251 at the repose angle .beta. of such material within the region of relatively high fluid velocity in accord with the material's fluid settling characteristics.

Abstract: A classifier using a swirling air current has two or more scatter plates turning about a common axis at different speeds and designed for causing outward motion of feed towards baffle rings placed round and turning with the scatter plates.

Abstract: A grain cleaner having a plurality of cleaning sections radiating outwardly from a grain inlet. Each cleaning section has upper and lower downwardly sloped screens over which grain flows by gravity to sift out fine foreign material. Upper and lower foreign material chambers underlie respective screens, and external bypass ducts bypass foreign material from each upper chamber to an associated lower chamber of each cleaning section. Each lower foreign material receiving chamber communicates with a centrally located foreign material discharge outlet at the bottom of the cleaner.

Abstract: An apparatus is provided for classifying and separating larger or more dense particles from fine particulate material entrained in a stream of air. The apparatus has a helically-shaped air chamber with a truncated frusto-conically shaped circumferential periphery. A series of extraction ports are disposed at spaced intervals along the truncated apex of the periphery. An adjustable blade means disposed at each extraction port segregates the outer fraction of particles from the air stream and diverts it into an extraction chamber surrounding the extraction port. The extraction chamber is pressurized to prevent the outflow of air from the helically-shaped air chamber through the extraction port and to remove the extracted particles to a collection point for further processing.

Abstract: Apparatus for screening a suspension of liquid, paper making fibers and undesirable rejects to remove a substantial portion of the rejects therefrom comprise a cylindrical screening member provided with circumferentially extending screening slots in the range of from greater than 0.008 inch to approximately 0.030 inch in width, and bars projecting from the inlet face of the screen and cooperating with rotating foils for creating a field of high intensity, fine scale turbulence adjacent the inlet face of the screen. The paper making fibers and other particles of elongated thin shapes can pass through the screening slots, but relatively chunky reject particles, which would pass through the larger openings of conventional paper making screens, are rejected without fractionation of the paper making stock or appreciable variation in the consistencies of the feed, accepts and reject flows.

Abstract: In a device for separating a liquid, as a cutting oil, from a mixture of metal chips and larger pieces of metal, such as bar ends and scrap, there is provided structure for preliminarily separating larger pieces of metal from the entire mass prior to the separation of the oil from the chips by a centrifuge. The structure includes a chute for feeding the mixture to be separated into the centrifuge, and a strong stream of air is caused to flow through the chute into the centrifuge. An opening is provided in the bottom of the chute intermediate its ends such that bar ends and other large pieces of metal which may be included in said mixture will drop through the opening, while air being drawn by the centrifuge into the chute through the opening will entrain the metal chips to prevent their dropping out of the opening and carry them onward through the chute into the centrifuge.

Abstract: The process of concentrating tin oxide minerals of fine particle size from material containing the same comprising the steps of forming an aqueous slurry of said material and subjecting said slurry to high intensity wet magnetic separation at a field strength and for a time sufficient to form a concentrate containing a major proportion of the tin oxide minerals originally present in the slurry.

Abstract: A plurality of truss-like supports are secured, as by welding, and in spaced relationship, to the underside of a screen cloth. The supported screen cloth is then removably secured in position in a vibrating frame to form therewith a vibrating screen. Each truss-like support includes a support rod formed of wire rod of predetermined diameter disposed with a major portion thereof spaced from and substantially parallel to the plane of the screen cloth, and with end portions thereof merging into the plane of the end pieces of selected wire rods forming the screen cloth and being welded thereto. A spacer wire, formed from wire rod of a diameter less than that of the support rod and to an approximate sinusoidal configuration, is disposed so that the upper tips, formed by the sine configuration, are welded to the bottom surface of the screen cloth and so that the lower such tips are welded to the upper surface of the support rod.

Abstract: A screw-type fine material classifier or washer having externally mounted support bearings with the ends of the screw extending through the end walls of the tank and waterproof seals. The bearings and seals being adjustable so that the screw may be moved both vertically and horizontally to adjust the clearance between the screw and the belly pan of the washer.

Abstract: Washing tank for separating particles differing the specific gravity by means of a liquid separatory medium using the float-and-sink method. The washing tank is provided with at least one collecting tray for removing the settled particles, which collecting tray can be reciprocated along the bottom of the washing tank and in the first extreme position is about centrally on the bottom of the washing tank, where it can collect settling particles, and in the second extreme positions rests on the edge of the washing tank, so tilted that settled particles contained in it can slide into a discharge device positioned next to the washing tank. Preferably, the washing tank is provided with two alternating collecting trays hingingly attached to arms fixed on a horizontal shaft swinging to and fro between two extreme positions.

Abstract: A centrifugal separator of the type commonly used in the papermaking industry is modified to discharge both the accept and reject flows from the smaller end of a frusto-conical chamber. The reject flow takes place through a peripheral opening and the accept flow through an axial opening. The method is also applicable to the separation of other fluid mixtures.

Abstract: An apparatus for separating particulate or lump material by size having a passage for the material, downwardly defined by a plurality of rotationally drivable discs which are arranged in several rows. The discs in one row mesh with clearance between the discs in the nearest adjacent rows on either side, such that together the discs form a screen extending along the passage from an inlet for the material to be screened to an outlet for lumps of the material which are too large to fall through the screen. The principle axes of the disc rows are oriented in the flow direction of the material through the passage and locate the discs in a flat-sided trough-like configuration. The discs are adapted to be driven in such a direction that they impart to the material on the screen a transverse arching movement upwards and towards both sides of the passage, while the material simultaneously moves towards said outlet.

Abstract: A cylindrical helically coiled compression spring made of a length of wire or rod having a circular cross section, the spring having interior windings providing the main spring action and end winding portions at least one of which is arranged to be supported against a spring disc, and the wire rod being formed to have a diameter which is greater in the region of the at least one end winding portion than in the region of the interior windings.

Abstract: A new heavy liquid parting medium comprising an emulsion of water and a substantially water immiscible heavy parting liquid for use in beneficiating ores by gravity separations such as sink-float processes. The specific gravity of the emulsion parting medium can be adjusted by proportioning the relative amounts of water and the substantially water immiscible heavy liquid. As-mined coal is beneficiated using a water-trichlorofluoromethane emulsion as the parting medium in a sink-float separation process.

Abstract: A chip screening system has a primary screening station for dividing an incoming flow of chips into a first acceptable fraction and a second fraction having acceptable chips and also both oversized and overthick chips. The second fraction is directed to a second screening station where the incoming flow will again be fractionated into an acceptable flow being screened primarily according to thickness and a second fraction being composed of oversized and overthick chips. The second fraction is then directed to a size reducing station.