Abstract: Apparatus and method for use in making non-woven fabrics by wet-laying an aqueous dispersion. The apparatus and method screens, separates and remover fiber defects and foreign matter above a prescribed size from other dispersion fibers. The apparatus includes a housing having an inlet and several outlets, an accelerator within the housing for creating relative movement between the dispersion fluid and fibers to axially align at least some of the fibers in the direction of dispersion flow to disperse those fibers in the dispersion and a separator within the housing for separating bundles and lumps above a prescribed size from other dispersion fibers. The housing discharges the bundles and lumps above the prescribed size from the process at one outlet, and passes the other dispersion fibers through to another outlet for use in the wet-laying process.

Abstract: An improved arc-welding flux recovery device which is compact, contamination-free, and can be economically maintained.

Abstract: A device for cleaning and recovering paper pulp includes a tank divided into inner and outer chambers by a fixed cylindrical sieve. The inner chamber also contains a rotating drum with blades that draw acceptable pulp from the outer chamber through the sieve to the inner chamber for discharge and moves rejected material through a helical path in the outer chamber toward another discharge point. The end of the helical path is blocked to form a dead space where the rejected material is concentrated and then periodically discharged.

Abstract: This specification discloses a greatly simplified method and system for recovering coal from a particulate coal bearing slurry (1) in which an appropriate hydrophobic liquid or emulsion of hydrophobic liquid in water (2) is introduced into the inlet of a centrifugal turbulent flow slurry pump (3) simultaneously with the introduction of said coal bearing slurry to said pump inlet, said hydrophobic liquid being introduced in a quantity sufficient to achieve substantially intimate contact between said hydrophobic liquid and coal particles in said slurry whereby the coal may be separated from the slurry by discharging the slurry from the pump directly over a simple static screen or other suitable separating device (4) whereupon the separated coal matter (5) may be collected for subsequent use.

Abstract: A sorting apparatus for sorting elastic balls for cleaning the inner surfaces of heat transfer tubes of a heat exchanger.

Abstract: An apparatus for dehydrating synthetic resin pellets comprising a plurality of interconnected truncated conically shaped dehydrating screens disposed vertically with their smaller diameters being uppermost, whereat wet pellets are forcibly directed so that moisture on the surface thereof will be removed by the screens. Blower means are provided for providing upward flowing air to move the wet pellets through the interconnected screens.

Abstract: A dredging apparatus is afforded having the improvements of a wedge-shaped dredge foot housing both a fluid opening and a filter member, the intake opening being located on the underside of the dredge foot and the filter member being located above the fluid intake opening so as to be placed between the intake and the suction conduit, the taper of the wedge foot being toward its forward edge and its underside being substantially planar. Also afforded is providing the lower end of the dredge housing with a forwardly directed lever means comprising a lever member capable of being reciprocally moved in order to effect the levering of large objects, thus enabling the location of the intake opening below such objects.

Abstract: Vacuum pneumatic conveying apparatus and method are utilized to transfer food products, such as fish, from a boat to a processing factory directly or via a tender vessel. Fish products such as salmon, are withdrawn from a fishing boat through an intake nozzle of a pneumatic vacuum system and entrained in an air flow, upwardly through inlet or receiving conduits of a vacuum, pneumatic, conveying system, and on through a product separator of an in line assembly of an upper product separator and a lower liquid separator. Salmon continue on flying out of the product separator and commence their downwardly momentum and gravity induced travel through discharge conduits, encompassing essentially non flowing air maintained under continuing vacuum.

Abstract: This invention provides means to screen long, slender objects from a flowing fluid, and more particularly provides means to clear jammed objects therefrom. The screening means comprises a set of opposed, aligned, undulating surfaces, preferably formed as corrugated plates, located within a conduit, that can be moved apart to permit the removal of trapped debris. The plates are so mounted as to be transversely movable relative to the conduit, and are each movable relative to the adjacent plates so as to permit increasing the separation between adjacent plates when the plates are moved to outside of the conduit. The liquid screening means of this invention can usefully be included in a suction type dredging device, between the inlet nozzle and the pump.

Abstract: A portable, dry-placer mining apparatus is provided with a vacuum chamber which defines a contained region of lower-than-atmospheric pressure which establishes the mode or means for drawing material into the chamber. The material is then ejected therefrom at a rate determined by the differential pressures established internal and external to the vacuum chamber. To prevent material impaction from interferring with the vacuum controlled output flow of material, any tendency of the material toward impaction is disrupted by an air stream flowing therethrough in response to the lowered pressure within the vacuum chamber. The material is output to a vacuum controlled separator device which is vibrated to separate denser from less-dense materials. A vacuum responsive frequency control is incorporated in the vacuum responsive vibratory drive of the separator device. The entire device is easily manually transportable and may be fitted to a conventional backpack frame.

Abstract: This invention provides dredging means having means to screen long slender particles wherein the long dimension extends in the direction of flow through a fluid-flow conduit. The screening means comprises a pair of opposing corrugated surfaces, the folds or corrugations on the opposing surfaces being substantially parallel, and separated by a distance, and having a wave length, determined by the size particle to be screened. Preferably, the corrugated surfaces are formed as a plurality of corrugated plates inserted within and extending along the direction of fluid-flow in a conduit. The axis of curvature of the corrugations or folds extend perpendicular to the flow of the stream.

Abstract: Debris is separated from pneumatically conveyed textile fiber tufts moving through a conduit by diverting a flow of air and debris from the conduit and returning the flow of air to the conduit so as to restore the volume of air flowing through the conduit.

Abstract: A device for fiber fractionation to analyze for coarse particles or chips in which fractionation takes place by washing a sample of the fiber material on a horizontally disposed slotted plate submerged in water, a central bundle-type nozzle which extends from above into the water above the slotted plate, the jets of which are directed downwardly, preferably angularly, against the slotted plate, and means for collecting the material passing through the slotted plate.

Abstract: A separator for separating coarse particles from cellulose pulp suspensions and the like comprises a first separation chamber provided with an inlet for incoming mixture, a first outlet for the light fraction, and an outlet for an intermediate fraction enriched in coarse particles. A second separation chamber is provided with a second inlet, a second outlet for a light return fraction, and an outlet for separated heavy fraction, the outlet for intermediate fraction being connected to the second inlet leading from a first zone in the first separation chamber. Said zone has a higher pressure than a second zone connected to the second outlet, the second zone being located in the first separation chamber or connected to the latter, the first and second separation chambers thus communicating to form a circuit.

Abstract: The method is intended for separating a flow of pulp containing impurities of coarse particles, partly light and partly heavy particles, by means of a main sieve or the like, into at least one pulp flow and one coarse reject flow. The coarse reject flow is separated by a hydrocyclone separator of a known type into a pulp flow, a light reject flow and a heavy reject flow. Advantageously, the light reject flow is separated by a bow sieve into a flow enriched in light particles and a flow enriched in fibers and which may be returned to the main sieve.

Abstract: A paper machine screening apparatus generally includes a centrifugal pump member mounted for rotation about the axis of a tubular screen plate. A delivery passageway extends concentrically about the pump impeller for receiving pumped stock flow and includes an annular axially extending passage formed between a ribbed hub surface of the pump and the screen. Flow through the screen is passed from the screening apparatus to headboxes. Downstream of the annular passage is an end cavity for receiving particles unable to pass through the screen holes which are washed into the end cavity by the axial flow through the annular passage. The ribbings on the hub surface serve to agitate the stock flow to raise pressure forces tending to force flow out through the screen holes.

Abstract: Defectively made absorbent articles (e.g., disposable diapers) are shredded for reclamation, and their fluff fillers, mixed with undesired scraps, are fed downwardly towards a forwardly moving horizontal stretch of a conveyor screen. Fluff fibres are forced into a collecting chamber under said screen stretch by maintaining a subatmospheric pressure therein to generate a downward air flow through the screen. Above the stretch are a succession of separating chambers. Under the screen stretch, near the front of each such chamber, is an air outlet from which air is blown upward to lift material off of the screen. Near the front of each chamber, above the screen, is a paddle wheel rotor that propels lifted material rearwardly in the chamber, thus maintaining agitated circulation of material in each separating chamber. When one separating chamber is overloaded, excess material is carried on the screen into the next forward one.

Abstract: A duct increasing in cross-sectional area is provided with a screen means on its upper wall. An adjustable baffle is hingedly fixed to the lower wall of the duct at the inlet. Air-borne material carried in an air stream introduced at the inlet is separated from the stream by projection against the screen. The adjustable baffle directs the air-borne material onto the screen.

Abstract: An in-line apparatus for separating oversize particles from a pressurized fluid slurry which comprises:a rigid, hollow body member capable of withstanding the pressure of the fluid slurry, the body member having a valved slurry inlet port and a slurry outlet port, each port adapted to mate with slurry conduit means;a washer access port opposite from and in axial alignment with the slurry outlet port;a hollow, open-ended screen assembly fixedly mounted within the body member between and in axial alignment with the slurry outlet port and the washer access port;a valved oversize particle discharge port at the lowermost end of the body member adapted to mate with oversize particle conduit means; andretractable backwasher means externally mounted on the body member in axial alignment with the washer access port and the screen assembly, where the backwasher means comprises a fluid discharging spray head adapted to pass axially through the interior of the screen assembly, whereby a pressurized backwashing fluid is d

Abstract: A method and an apparatus for transporting items such as chopped nuclear fuel pins from a receiving station to a discharge station. The apparatus contains a liquid for transporting the items in an inlet duct which extends downwardly from the receiving station to a region where it is joined to an outlet duct which extends upwardly to the discharge station.The region is connected to a source capable of applying a pressure pulse to the liquid so as to displace the liquid upwardly in at least the outlet duct and thereby transport the items through the apparatus.At least two apparatus may be connected together in series relationship to provide a plant for the transport of the items through the plant.

Abstract: A separator system for separating grinding bodies and ground material in an agitator mill wherein stationary and moveable or oscillating separator members in a grinding chamber define a variable gap which narrows when a moveable separator member moves against the flow of ground material.

Abstract: A cyclone separator for separating heavy particles and dust particles from fibre material. The separator includes a cyclone housing (2), an inlet tube (9) that opens substantially tangentially into the housing (2), an overflow pipe (6) for the removal of cleaned light-weight fibre material, and an underflow outlet (4) for discharging heavy particles and dust particles. To improve dust removal, a sieve member 7, 8 is arranged inside housing (2) substantially co-axial with the housing axis and into which inlet tube (9) opens tangentially. Additionally, pin-studded or spike-studded strips are mounted on an inside face of the cyclone housing or of the sieve member to preliminarily open up the fibre material. A coaxial sieve member having flat bars with vertical upper portions and inwardly-curved lower portions that bound a co-axial lower sieve opening is also provided.

Abstract: A filter system and method for extracting entrained lint particles from an effluent air stream prior to discharge into the atmosphere. The system and method are intended for use in combination with a cyclonic separator of the type having a vertical settling chamber for separating relatively dense fiber product from airborne lint entrained in a product stream. The filter system includes a housing forming an air stream inlet, a lint discharge outlet and a clean air outlet. A rotatable screen is interposed between the air stream inlet and the clean air outlet whereby the entrained lint is accumulated on the screen as the effluent air stream flows through the screen for discharge into the atmosphere. The accumulated lint deposit is presented to the lint discharge outlet as the screen turns. A first fan blower is coupled to the separator for inducing an upwardly moving inner vortex for entraining the airborne lint, and coupled to the filter inlet for discharging the entrained lint onto the rotatable screen.

Abstract: Apparatus for separating snakeskins and fines from pellets in a collection of polymeric material wherein a first nozzle impinges the collection of polymeric material in a stream of air on a moving screen having a mesh size such that the screen will allow the air and fines to pass but will retain the pellets and snakeskins, the air stream carrying the fines through the screen into a closed compartment. A second nozzle is positioned to allow air from the closed compartment to move upwardly through the screen at a different location from the first nozzle to lift and remove snakeskins from the screen.

Abstract: The outlet of a pneumatic conveyor delivers a mixture of tobacco leaves and sand to the upper end of an arcuate duct which is located below a rotating air withdrawing wheel. That wall of the duct which faces the outlet of the pneumatic conveyor has holes for the passage of sand particles whereas the leaves descend in the duct and are evacuated by a cell wheel. The air withdrawing wheel draws air from the outlet of the pneumatic conveyor as well as from a suction chamber which is adjacent to the perforated wall of the duct and serves to collect the particles of sand. The rate at which the air flows from the suction chamber and/or the speed at which air flows from the outlet of the pneumatic conveyor is adjustable by pivotable flaps.

Abstract: An improvement in the screen circumscribing or partially circumscribing the rim of an agitation tank is disclosed. A screen substantially impermeable to the charcoal is provided which is inclined inwardly at an angle between about 35.degree. and 55.degree. from vertical. The metal-bearing charcoal adhering to the screen is readily washed from the screen by the rolling motion of the mixture in the tank.

Abstract: A glass bead separating apparatus and method are disclosed, for use with a slurry blast cabinet. The system is capable of continuous operation, so that glass beads which are broken and undersized can be separated out of the slurry along with debris from the blasting operation, on a continuous basis while blasting takes place, and the slurry can be continuously returned to the blasting cabinet in the purified condition. Used slurry is withdrawn from a hopper at the bottom of the blasting cabinet, pumped up to the top of the separator apparatus and delivered through a nozzle over an inclined screen sized to pass everything but reuseable, whole glass beads. The reuseable beads are collected in a bin, while the remainder passes down onto another, much finer screen which retains nearly everything but the liquid slurry medium, which is preferably water. The relatively clean water drops into a holding tank at the bottom of the separator apparatus, with an overflow weir provided to maintain a preselected water level.

Abstract: An apparatus for removing dust from a fiber sample for subsequent analysis is disclosed. A first upper cylindrical chamber containing a fiber sample has a tangential air jet and a radial air jet installed to swirl and tumble the fiber sample in a cyclonic fashion, thus liberating the dust from the sample when either a positive or a negative pressure is applied through the air jets. The liberated dust particles are then screened out through a 100 mesh screen filter and exhausted through a funnel. The device can be equipped with a second stage chamber containing a plurality of step-stage filters and a third stage plurality of microfilters to selectively screen the dust particles. A blow bottle containing an aqueous medium to absorb even the finest dust particles or gas can also be added as a fourth stage.

Abstract: An apparatus for the separation of solids and liquids from a suspension has a hollow drum rotatably mounted about a horizontal axis. The drum wall is a screen made of a plurality of wires, preferably wedge-sectioned wires; spaced apart in a parallel arrangement and lying axially along the drum. Inlet means direct the suspension against the inner surface of the wall at an angle less than right angles, and preferably substantially tangentially to the inner surface, in a direction opposing the rotation of the drum. The separated solids remain within the drum and are extracted therefrom by suitable means.

Abstract: In removing impurities, such as printing inks, binders, fiber fragments and pigments, from a fibrous suspension of waste paper containing water, the fibrous suspension is directed downwardly over an inclined sieve for removing the impurities through the sieve. In its length direction between its upper and lower ends, the sieve is divided into a number of individual sections. A triangularly shaped groove-like trough is located between the lower end of one section and the upper end of the next downwardly adjacent section. The trough extends transversely of the length of the sieve and is shaped to provide a swirling movement to the suspension flowing into the trough. At the outlet from the trough a flow-stemming device is provided for affording the uniform level of the suspension as it flows over the next section of the sieve.

Abstract: In the opening and cleaning of fibrous materials apparatus is provided which includes a plurality of rotatable beaters within a housing, curved under grids beneath each rotatable beater, baffle plates above and between the beaters, a perforated screen positioned above and adjacent the beaters and a suction hood positioned over and embracing the whole upper surface of the perforated screen. The screen is inclined to the horizontal and the apparatus includes a suction duct extending across the lowermost edge for withdrawing air from an inlet slot along the opposite edge to create an air stream flowing over the whole surface of the screen such that dust and unusable fibres passing through the screen are carried away to a waste extraction duct.

Abstract: Apparatus and method for removing dust and trash from tufts of opened cotton fiber stock includes entrance and exit ducts for airborne transport of the tufts to and from a housing having passages for the tufts therethrough, a screen disposed therein, a pair of counterrotating rollers with projecting pins for regulating passage of the tufts to the screen, a suction trough for causing high velocity impingements of the tufts against the screen for shaking cotton dust from the tufts and through the screen thereby forming a mat of tufts on the screen and passing air at a high velocity through the screen for removing cotton dust from the mat, and a moving paddle wheel for removal of the tufts from the screen disruptively of the mat and propelling the tufts in a tumbling floccular state farther through the passages toward the exit duct. The housing contains a plenum with a porous impact and filtration panel for receiving tufts from the entrance duct against the panel and directing the tufts toward the screen.

Abstract: A mobile vehicle having self-contained apparatus for classifying, cleaning and reconstituting granular or pelletized materials, such as catalysts used in chemical plants, without polluting the surroundings, is adapted to travel from plant to plant over conventional highways and quickly placed in operating condition to remove contaminated granular materials from their beds or towers in chemical plants even when hot and process the materials to remove dust and undersized particles, to classify the granules into batches of different sizes for reuse and to filter out pollutants to protect the surrounding atmosphere.

Abstract: Sifting equipment for fine-grained bulk material, particularly flour, provided with a transit chamber inserted in the transmission line of the bulk material and containing a sieve, exposed to the action of a blower, is improved by having the transit chamber (9) mounted vertically as regards its lengthwise axis.

Abstract: A method and apparatus for classifying solids and transporting a solids-laden fluid containing large particle size solids which will tend to plug a tubular transport means and small particle size solids which will pass through the transport means without plugging, including passing the solids-laden fluid through a screening means and removing therefrom large particle size solids having a maximum dimension greater the internal diameter of the fluid transport means while passing through the screening means the solids-laden fluid containing small particle size solids having a maximum dimension smaller than the internal diameter of the fluid transport means and thereafter passing the solids-laden fluid containing the small particle size solids through the fluid transport means.

Abstract: The device for wet classification of a mixture of solid components with rect to size, according to the invention, has two circular chutes "2" and "2a" situated tangently next to each other at the same level and equipped with one common feeding nozzle "3". In the outer walls of the chutes "2" and "2a" in the region of their contact there is a distributing hole "5" in which, opposite the inlet of the feeding nozzle "3", there is the dividing wedge "6". The device has separate sieve planes "1" and "1a" fastened to the inner edges of the bottoms of the circular chutes "2" and "2a". A vibratory unit "7" is located on the central vertical axis of each sieve plane.

Abstract: A frame structure having a pre-dewatering unit fixedly mounted thereon and a final-dewatering and inspection table unit movably mounted thereon. The pre-dewatering unit includes a vertically extending receiving compartment through which the mixture of water and vegetables passes upwardly from bottom to top and a pre-dewatering chute adapted to receive the mixture flowing over the top of the receiving chamber. The pre-dewatering chute includes an upper chamber and a lower chamber separated by a screen member. The screen member is positioned at an angle to the horizontal so that the solid material in the mixture will pass over the top surface of the screen member and a substantial portion of the liquid material will pass through the screen member into the lower chamber. The final-dewatering and inspection table unit includes a final-dewatering section and an inspection table section, both of which are vibrated by a suitable vibratory means.

Abstract: Small batches of grain for household use are vacuum cleaned in a portable apparatus which can receive vacuum power from the hose of a household vacuum cleaner. Grain requiring cleaning is introduced into the device through a transparent top door and gravitates into a hopper within the apparatus having a restricted grain outlet. When suction is applied through the housing of the apparatus which is vented to atmosphere, air and uncleaned grain are propelled continuously on a circuitous path until the desired clean state of the grain can be observed through the transparent door, at which time another door of the device is opened to permit clean grain to pass into a holding chamber. A waste chamber is also provided in the apparatus and is separated by a screen from the main treatment chamber.

Abstract: An apparatus is disclosed for separating polyethylene film from paper fibre. The polyethylene film contaminated with paper fibres is subjected to treatment that converts the paper fibres into substantially uniform balls which are separated by gravity by being entrained in a stream of air with the polyethylene film pieces and impacted against a plurality of impact surfaces and the relatively light polyethylene film being separated from the relatively heavier damp paper fibres by means of a plurality of baffle separators relying upon gravity separation of the heavier components. Provision is made to remove the damp paper fibre balls and recover the polyethylene film from the apparatus.

Abstract: A fractionating apparatus for separating fine fibers from coarse fibers in water containing a certain amount of air. A spray nozzle is arranged in a vessel and directed towards a screening cloth incorporated as a part of the vessel walls and which, on its discharge side, is arranged for free runoff of the fine particles and the part of the liquid passing through the seal means to its discharge side, while coarse particles and the other part of the liquid is bounced off the inner side of the screening cloth and collected in the vessel to a predetermined liquid level maintained by allowing the liquid to depart through an outlet. A desired pressure difference is maintained across the sieve means. The vessel is closed with the exception of the places where the sieve means are situated and where the outlet is arranged.

Abstract: In a timbering operation wherein the felled trees are fed into a chipper for conversion to chips at the timbering site the chips are fed into a trailer-mounted rotary cylindrical screen which separates the chips from dirt and fine bark particles. Preferably the chips entering the cylindrical screen are blown into engagement with an impact plate to aid in disloading particles of dirt and bark from the chips. The chipper may be mounted on the same trailer or may be a separate trailer-mounted unit.

Abstract: Recovery of paper fiber for reuse from waste paper materials containing plastic sheet and film is facilitated by the combination of a pulper in which the waste paper materials are pulped in a pulper equipped with a junk remover connected with the bottom of the pulper tub by a chute and provided with a recycling circuit by which the plastic and other lightweight trash picked up by the conveyor buckets in the junk remover is removed from the pulping system, passed through a detrasher for removing bulky objects, then passed through a deflaking station, and then returned to the pulper tub for further defibering. This continuous withdrawal of liquid from the junk remover and its return to the tub act to maintain the hydrostatic head in the tub at a higher effective level than in the junk remover tower and thereby to promote transfer of the plastic and other lightweight trash to the junk remover for removal by the recycling circuit.

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: An apparatus and a method of cleaning and polishing capsules in which the capsules are blown against one side of an electrically charged screen to clean dust therefrom by their impacting on the screen. Air is drawn through the screen from the other side of the screen to draw off the dust through the screen. The capsules drop down from the screen and are delivered to a rotating inclined drum having a lining of napped fabric wherein the capsules are tumbled for residual cleaning and polishing.

Abstract: Toner particles which are removed from a photoconductive drum are trapped by a moving filter at a toner collection station and on movement of the filter to a toner discharge station, the toner is discharged into a toner reservoir. The filter may be of such a size that only the toner particles which enhance image development will be trapped thereon while the smaller toner particles will pass therethrough.

Abstract: Apparatus for separating or classifying the contents of a flowing slurry comprising a descending flow surface having a low profile and associated therewith a relatively low head box, the latter of which is distinguished by a relatively restricted cross sectional area adjacent its top. The flow surface is characterized by screen sections successive of which differ in orientation and profile whereby to produce a compact structure having a high capacity for separation of liquid from a flowing slurry. The design of the head box is such to enable a fast and effective delivery of slurry in spite of the low head provided.

Abstract: This disclosure relates to apparatus for cleaning natural fibers of their contaminants by passing the same through a pair of rotary drum sieves each having a porous peripheral surface subject to a vacuum whereby natural fibers adhere to the porous peripheral surfaces and contaminants are drawn therethrough, the drum sieves being disposed with portions of their peripheral surfaces defining a throat through which the fibers pass, and means contiguous the throat for cutting off the vacuum effect of the first drum sieve whereby the fibers are transferred from the first drum peripheral surface to that of the second drum.

Abstract: An enclosed particular dry product is conveyed through a conduit by a gaseous fluid formed by a vacuum blower. Metered hoppers feed the product into the conduit. A cyclone removes the product from the fluid and conveys the same to a separating screen. The desired size product is recovered and passed through a flexible sock to minimize breakage and loaded into a vessel. The undesired size is fluid conveyed to a recovery receptacle.

Abstract: A no-discharge concrete reclamation system that eliminates all waste products and associated pollution. In addition to separating and washing sand and aggregate as provided in conventional systems, the invention provides for holding the water-cement slurry in suspension while continuously circulating same with a transfer pump to a point near the batching plant. On demand, slurry for batching from the circulating stream is provided to the mixers. Preferably, clarified wash water is held separately and used to provide mixer wash water, and/or make-up water for the slurry.

Abstract: Hollow microspheres having thin and very uniform wall thickness are useful as containers for the deuterium and tritium gas mixture used as a fuel in laser fusion targets. Hollow microspheres are commercially available; however, in commercial lots only a very small number meet the rigid requirements for use in laser fusion targets. Those meeting these requirements may be separated from the unsuitable ones by subjecting the commercial lot to size and density separations and then by subjecting those hollow microspheres thus separated to an external pressurization at which those which are aspherical or which have nonuniform walls are broken and separating the sound hollow microspheres from the broken ones.