Abstract: The device for removing flowers from a fruit tree by pulling off from their branch is formed by a rod, a gripping and a puller. The gripper can be a handle. The puller is mounted at the end of the handle for pulling off flowers. The puller can be formed of at least one roller provided with fibers in the form of bristles, each roller being mounted articulated, freely rotating at the end of the rod, so that the transverse displacement of the rod into contact with the branch induces a rotation of each roller.

Abstract: A screened sliding drawer assembly comprises an upper plate comprising a central aperture and at least two side apertures disposed on the sides of the central aperture. The screened sliding drawer assembly further comprises at least two removable lids disposed above the at least two side apertures. The screened sliding drawer assembly further comprises a lower plate comprising a second central aperture. The screened sliding drawer assembly further comprises a glide drawer, disposed between the upper plate and the lower plate, comprising at least one screen. The screened sliding drawer assembly further comprises an output channel disposed below the lower plate.

Abstract: The invention relates to an air jet sieve device having a housing, at least one sieve for insertion in the housing, a sieve deck and chamber located below the sieve, a slotted nozzle beneath the sieve deck, a drive for the slotted nozzle, an air inlet to the slotted nozzle, an air outlet through the housing and out of the chamber located beneath the sieve deck, and a control unit to control operation of the device. The invention also relates to a method that permits not only detection of the sieving progress during a sieving process but also provides a criterion to permit establishing the sieving time. This is achieved by equipping the sieving machine with a measuring sensor through which the particles in the air outlet flow are detected triboelectrically and which are correlated with the sieving progress to permit establishing the sieving time.

Abstract: An apparatus and process are provided for the removal (by washing) of residue from a screen during a screening process.

Abstract: A vibratory separator including a housing having a drilling material inlet and at least one basket, at least one screen assembly configured to be disposed in the at least one basket, an actuator connected to the at least one basket, wherein the actuator provides vibratory motion to the at least one basket, a sump configured to receive drilling material that passes through the at least one screen assembly, and at least one spray nozzle for cleaning the vibratory separator is disclosed. A method for cleaning a vibratory separator including providing instructions to a programmable logic controller to activate at least one spray nozzle disposed on the vibratory separator is also disclosed.

Abstract: An apparatus and process are provided for the removal (by washing) of residue from a screen during a screening process.

Abstract: A grain processor comprises a conveyor, air-suction means, and air-blowing means. The conveyor has a surface defining a conveying course on which grains are disposed, and the surface has holes smaller than the grains. The air above the surface is sucked downward through the holes by the air-suction means. The air-blowing means blows air upward through the holes at a predetermined position in the conveying course so as to apply blowing-up force onto the conveyed grains on the surface reaching the predetermined position.

Abstract: An apparatus for separating fibers from reject material produced in the manufacture of recycled pulp. The apparatus comprises a rotating reject cylinder provided with openings, to one end of which the reject material is fed and from the other end of which it is discharged, water nozzles for feeding water to the reject material in the cylinder to separate fibers from it, a collecting basin for recovering water and the fibers separated with it, and discharge channels connected with the collecting basin, and means for discharging fibrous water and light and heavy particles from the collecting basin. The collecting basin is formed of two basin structures at least partly within each other and connected with each other.

Abstract: A steam distributor that uses a porous metal plate to replace the conventional screen plate of a steam shower for distributing steam to a moving web such as the web of a paper making machine. Steam showers using a steam distributor with this porous metal plate can deliver extremely uniform steam to the surface of a paper web. Profiling steam showers constructed by using an array of the steam distributors are able to deliver the best profiling results for various paper products. The porous metal plate can be considered as an equivalent of a screen plate with thousands of micro-orifices arranged tightly in both the machine direction and the CD direction.

Abstract: The invention relates to method and device for cleaning grain, whereby a mixed product from cleaning is run through a light grain separator.

Abstract: Self contained filter backpurge systems useful for totally enclosed processing mills and for clean in place (CIP) processing material processing mills.

Abstract: A jigger for the processing of minerals such as coal, consisting of two traveling troughs, the upper trough being equipped with a sieve and closed from below by a continuous flexible membrane, the lower trough interrelating with the diaphragm of the upper trough, acting as a piston and giving water vertical pulsation. The troughs are linked to each other via double-arm levers, hinged in the supports. The double-arm levers together with the troughs form a system of hinged parallelograms, providing uniform distribution of pulsations along the whole capacity of the upper trough that produces conditions for the intensification of the jigging process. Besides this intensification, decreasing of energy-consumption and simplicity of design having been achieved. A laboratory sample was made and its testing showed good technological results and confirmed the reliability of a unit simple in manufacturing, operating and maintenance.

Abstract: The invention relates to a method and an arrangement for cleaning the screening device (2) of a screen (1). The screen (1) comprises at least said screening device (2) which has openings for the separation of particles of different sizes into fine material and coarse material, an actuator means for moving the screening device, a first conveying means (4) for guiding the material to be screened to the screening device (2) of the screen and a second conveying (8) means for moving the fine material that has passed through the screening device (2) and means (9) for guiding the separated coarse material away from the screen (1). For cleaning the screening device (2) a material is blown with the pressure medium at least at intervals through the screening device (2) in the opposite direction regarding fine material passing through, the particle size of which material being at least mainly smaller than the size of the openings of the screening device (2).

Abstract: An arrangement and a rotor for screening of pulp is disclosed that is suitable for the screening of chemical and mechanical pulps, i.e. fiber suspensions of the wood processing industry. A feature of the arrangement and rotor is that inside the rotor (16) there is arranged at least one dilution liquid chamber (24′, 24″, 24′″) restricted by a surface of the rotor (16), which surface is provided with means for connecting said at least one chamber (24′, 24″, 24′″) with the screening space defined between the rotor and the screen drum in such a way that dilution liquid from said at least one chamber (24′, 24″, 24′″) is brought into the screening space at a distance of at least 20 mm from the inner surface of the screen drum (14).

Abstract: An air classifier with enhanced air flow which maybe used for the simultaneous recovery of two or more distinct grades of foundry quality sand from a single sand stream. The air classifier exhibits improved performance by drawing into the classification chamber, through the use of suction, incoming air through a honeycomb followed by a screen section having two or more screens. The honeycomb removes swirl in the air and the screens slow down the fast moving air more than the slow moving air. After passing through the screens, the velocity profile of the air in the chamber is flat across the inlet flow path and, as a result, improved classification performance is achieved. Classification performance may be further enhanced through the use of a vibrating screen feeder for spreading the incoming particle stream before entrainment in the air flow within the classifier and through upward flowing air in one or more product receiver sections.

Abstract: A compact dedusting apparatus is mounted on the machine utilizing particulate material requiring contaminant cleansing to provide an economical and effective decontamination of particulate material immediately before utilization of the material. The dedusting apparatus includes a downwardly sloped infeed chute having an opening at the bottom thereof. A metering device in the form of a rotatable finned hub blocks the opening to constantly meter the flow of particulate material through the dedusting apparatus. The metering device is formed with flexible blades oriented at a slight angle to the slope of the infeed chute to provide a constant flow of material through the opening. A flow of air is directed through a wash deck positioned below the infeed chute to cleanse the particulate material. The air flow is directed along multiple paths including a path defining an air knife associated with the wash deck to facilitate the cleansing of the material.

Abstract: The invention relates to a method and an arrangement for cleaning the screening device (2) of a screen (1). The screen (1) comprises at least said screening device (2) which has openings for the separation of particles of different sizes into fine material and coarse material, an actuator means for moving the screening device, a first conveying means (4) for guiding the material to be screened to the screening device (2) of the screen and a second conveying (8) means for moving the fine material that has passed through the screening device (2) and means (9) for guiding the separated coarse material away from the screen (1). For cleaning the screening device (2) a material is blown with the pressure medium at least at intervals through the screening device (2) in the opposite direction regarding fine material passing through, the particle size of which material being at least mainly smaller than the size of the openings of the screening device (2).

Abstract: A separator includes a continuous inclined screening belt that passes over an upper roller and a lower roller to screen debris from municipal wastewater. The debris is then conveyed to a debris discharge outlet. A puddle of debris-laden wastewater forms a hydrostatic pressure head on the upper surface of the screening belt to assist in forcing the wastewater through the screening belt. Wastewater that passes through apertures in the screening belt is deflected by a deflector plate that shields the return path of the screening belt. The screened wastewater is then directed to the wastewater outlet. In a preferred embodiment, a belt-cleaning brush is disposed along the return path and brushes clinging debris from the screening belt toward the debris discharge outlet. Additionally, the screening belt rides on and is supported by a perforated backing plate as it travels from the lower roller to the upper roller.

Abstract: A particle size classifier in which feed material composed of product and overs moves downwardly through a separator unit by the action of negative pressures created by a first air blower associated with the collection of product and a second air blower associated with the collection of overs. As the feed material moves downwardly, the product and the overs are separated with the product passing from within a screen unit to outside the screen unit and the screen unit preventing passage of the overs. Blowback air, applied to the screen unit from the outside cleans the cylindrical screen unit to permit continued passage of product through the screen unit.

Abstract: The invention provides an apparatus for screening a fibrous slurry including a rotatable drum whose circumferential wall includes a screen. The screen has spaced openings with longitudinal axes or elongations which are large relative to the transverse axes or gaps defined by the openings. The openings are disposed with their longitudinal axes extending circumferentially of the rotatable drum. The drum has at least one open end. A slurry delivery conveyor terminates adjacent to the drum for delivery of slurry within the drum.

Abstract: A vibratory separator having a resiliently mounted housing with a vibratory drive. A screen extends across the housing and a cover is positionable over the screen. The screen includes a discharge port therethrough aligned with a discharge passage for removing material from the top of the screen from the system. Another discharge passage cooperates with a manifold plate extending across the separator beneath the screen. An access port is provided through the cover and arranged to receive a discharge plug which can selectively close the discharge hole through the screen. In operation, separating or dewatering is first accomplished, the energy level of the vibration is reduced and a vacuum is drawn above the screen. Bleed air is allowed into the separator below the screen with a restricted flow so that a vacuum can be drawn. Once the material has dried, the vibrational energy can be increased and the plug removed from the hole through the screen. The process material may then be discharged from the unit.

Abstract: A method and a device for the separation of semiconductor material has the separation procedure carried out on screens coated with ice made of ultrapure water, optionally mixed with particles of semiconductor material. During the separation, the screens are sprayed with ultrapure water and the screen holes are cut free.

Abstract: Improved methods of screening particulate matter are disclosed. For example, aqueous mineral slurries containing at least 10 weight percent of finely divided mineral solids are mechanically size separated using vibratory screening and a self propelled recirculative rotating spray bar, prior to, and subsequent to various processing steps. The employment of the spray bar improves the screening process by preventing blinding of the screen, as well as increasing throughput. As a result this invention reduces screen residues and/or increases production rates significantly.

Abstract: A deck support framework system, being sectioned or modular, having one or more flooded support tubes 30A/30B. Flooded support tube 30A/30B is oriented essentially horizontal and attached at sides of a deck framework, aligned with fluid passage hole small 34A or threaded input hole 102 in the sides of a deck framework, allowing for the spraying of fluids through flooded support tube 30A/30B which has fluid exit holes 34B. Additionally or alternately a structural support for a vibrating screen or similar device, having one or more flooded support tubes 30A/30B, and having attached end members having fluid passage holes small 34A or threaded input hole 102, and having flat planar sides uttermost, or nearly so, with attached end members located at the open end portions of flooded support tube 30A/30B enabling the mounting of such a flooded structural support to vibrating screen side walls 50. Fastener holes are positioned as needed for both structural and fluid supply considerations in mating components.

Abstract: A gumbo separator has a continuous, inclined, moving screen belt which rides on and is supported by a perforated backing plate. The desirable portion of drilling fluids fed to the gumbo separator passes through the screen belt and backing plate and may be further processed to remove drill cuttings. The gumbo, containing gummy hydrated clays, are conveyed off the screen belt to the reserve pit. The gumbo separator provides a self cleaning screen belt, using a counter-rotating belt cleaning brush. A spray bar back-washes the screen belt with high pressure drilling mud to remove any gumbo lodged in the screen belt openings.

Abstract: A drum separator for separating brine shrimp eggs from a slurry containing an agglomeration of adult brine shrimp, brine shrimp eggs and debris includes a fluid source to maintain a slurry. The fluid source may be an internal spray jet disposed to spray against the slurry inside the drum for breaking up the agglomeration of adult brine shrimp, brine shrimp eggs and debris so that the brine shrimp eggs may pass through openings formed in the drum. An external spray jet is disposed to spray against the exterior surface of the drum for cleaning the adult brine shrimp and debris out of the openings in the drum. The internal spray jet is preferably an elongated pipe having a plurality of openings and is disposed inside the rotating drum. The external spray jet is preferably an elongated pipe with a plurality of openings and is disposed along the exterior of the rotating drum.

Abstract: The present invention is directed to an electrolytically produced screening material for the removal of fibers from suspensions during the production of pulp and paper. The screening material is a thin, smooth metal foil having perforations on the order of 10-80 .mu.m. And an open area of 5% to 40%.

Abstract: The invention provides a separator for removing small particulates from an air stream, the separator includes pneumatic separator with a relatively small filter element built inside the separator to remove particulates from the air stream down to as small as one micron. The pneumatic separator relies on a vortex effect and sudden changes in direction of the air flow to strip out most of the particulates, and because the very small particulates have insufficient mass to be dislodged from the air in this way, these particulates remain in the air stream and are carried to the filter element where they build up on the element. The build up is interrupted by the incoming air which flows aggressively around the element and strips parts of the build-up off the element. This ongoing random process can be supplemented if necessary by back flushing. Both the separated particulates and those stripped off the filter element accumulate in the separator for subsequent removal.

Abstract: A screening chamber for filtering paper coatings is cleaned with the use of a plurality of water sprays. The water sprays are provided by nozzles located on spray bars positioned transversely across the width of the screening chamber. The nozzles are oriented to direct selected spray patterns tangentially against the screens, and against the interior surfaces of the screening chambers, to remove particulates, debris and other contaminates which collect on the screen during the filtering process.

Abstract: An apparatus for classifying particles by size comprising: a source of direct potential having first and second terminals, a sieve electrode connected to the first terminal, a solid electrode connected to the second terminal. Particles are fed to a transfer point located between the sieve electrode and the solid electrode such that the particles disperse and oscillate between the sieve electrode and the solid electrode whereby smaller particles pass through the sieve electrode. The new equipment has five adjustable operating parameters, screen angle, spacing between electrodes, field strength, powder input rate and electrode taper. The taper between electrodes is usually small, 0.3 to 0.4 of a degree with the larger opening at the top. The taper is used when the input powder is fine and the particle size differential is skewed either towards the high or low side. The purpose of the taper is to reduce the possibility of arcing at the input as well as to control dispersion of the particles.

Abstract: A vibratory screen apparatus (10) for the separation of solids has a cleaning system to clean the screen bed (15) of adhering solids, such as matted fibrous materials. A water discharge assembly (52) includes a water dispensing tubular member (60) in which elongate slots (76, 78) are provided to discharge pressurized water in a continuous stream or curtain across the entire width of the screen bed (15). The water dispensing tubular member (60) is mounted on a movable slide (54) for back and forth movement along the length of the screen bed (15) by a sprocket chain (72). An endless belt conveyor (104) has an upper run (108) on which the solid materials are deposited enclosed within a tubular conduit (114) for protection of the solid materials being transported by the conveyer (104).

Abstract: The production capacity of a conventional high pressure feeder having a pocketed rotor with a slotted screen at the low pressure outlet port is significantly increased by constructing the screen so that its arcuate bars have a width much less than normal, and thus a much greater open area of the screen is provided. Structural integrity is maintained by providing a reinforcing bar extending transverse to the arcuate screen bars, typically attached at the convex mid-point area. The screen is formed from a cast metal body, and the width of the arcuate screen bars is typically between about 0.14-0.20 inches.

Abstract: A screen apparatus for paper making capable of substantially fully recovering fibers from a paper feedstock which has been subject to a pulper and discharging a residue while dehydrating it. A paper feedstock is subject to two-stage maceration and two-stage screening through first and second screen chambers each provided therein with a screen and macerating blade combination. The screens are each cleaned by the macerating blades, so that fiber pieces contained in the paper feedstock are substantially fully recovered with high efficiency and a residue is discharged while being substantially free of fiber pieces and substantially dehydrated.

Abstract: A strainer device is disclosed for continuously separating liquids from a solid/liquid mixture, the strainer including a screen receiving said solid/liquid mixture and a container under reduced pressure disposed under the screen to collect the strained liquid. High pressure fluid is used to roll the solids off the screen to insure that the solids do not plug the screen. If recycled water is used, a spring-loaded nozzle is also provided which may be purged. The device may also be used for thickening a solid liquid mixture. Preferably an angled or conical screen is used.

Abstract: This invention relates to a screen separator for separating metal adsorbent particles from a pulp and includes a screen separator for separating metal adsorbent particles from a pulp including an open topped and closed bottom cylindrical screen for axially vertical location, in use, in a tank containing pulp with the open top of the screen at or adjacent the full pulp surface level in the tank, an impeller which is located in the screen with its axis of rotation vertical, drive means, and a drive shaft connecting the drive means to the impeller with the impeller being adapted to drive pulp in the screen upwardly to a level above the surface level of the full pulp level in the tank when the impeller is rotated in the screen. The invention further extends to a method of separating the particles from the pulp by means of the separator and to a metal recover process which employs the separation method.

Abstract: An apparatus and method for treating fiber suspension is especially applicable for pulp screening in the wood processing industry, particularly for the separation of light particles from fiber suspensions. The apparatus comprises an outer casing with conduits for inlet pulp, accepts, heavier rejects and lighter rejects; a filter cylinder and a rotor, the surface of which is provided with at least one protrusion; and an opening for guiding the light rejects through the surface of the rotor.

Abstract: A method and apparatus for treating a fiber suspension to thicken or screen it. The suspension is fed to the gap between a filter surface and a counter member, and accepts flow through openings in the filter surface. Rejects continue along the filter surface to a rejects outlet. Relative movement, preferably relative rotation, is effected between the filter surface and counter member. The suspension at the filter surface is coarser and/or of higher solids concentration than the accepts. This coarser suspension is subjected to a force component by a protrusion on the counter member surface that tends to move it away from the filter surface, in a guided manner (between the protrusion and a guide plate). A second protrusion in the form of a backwardly inclined plate forces fresh suspension toward the filter surface to take the place of the suspension just moved away from the surface.

Abstract: A backwash strainer including a body, a strainer element having an inlet side contained in the body, and a space defined between the body and the strainer element. The body includes an inlet to the strainer element and an outlet from the annular space. A nozzle for directing cleaning fluid against the inlet side of the strainer element for dislodging particulate matter from the inlet side of the strainer element mounts to the body. A backwash arm for collecting the cleaning fluid and dislodging particulate matter mounts to the body. The backwash arm is positioned adjacent to and is in close proximity to the inlet side of the strainer element and the nozzle. The backwash arm has an axially extending slot defined by two spaced members having ends positioned adjacent to the nozzle. The backwash arm and the nozzle together may be moveable about a central axis relative to the strainer element.

Abstract: A device for fractionating pulp suspensions has a series of vertical filter sheets attached to a horizontal shaft. Suspension is sprayed against the sheets to effect a separation of coarse and fine solids. Cleansing liquid is also sprayed against the sheets to keep the filter holes open and the fabric sheets are movable with respect to the sprays.

Abstract: A separator for continuously separating comparatively small particles of light bulk density such as, for example, expanded polystyrene x-beads from unexpanded polystyrene beads produced by an expansion process, preferably including a vibrating screen of a mesh size for passing smaller particles, but not larger particles, and a pulsed pressure differential across said screen for drawing smaller particles through the screen and for clearing the screen.

Abstract: The invention relates to a method for controlling pressurized screening devices in which fiber pulp is fed to the pressurized screening device and is divided into the accepted portion of the fiber pulp passing through perforations of a cylindrical screenplate and the rejected portion which is removed from the screenplate, the perforated screenplate being treated by a device movable relative thereto and rotatable around the center axis of the screenplate, the fiber pulp being fed parallel with the center axis of the screenplate to baffle blade assembly comprising at least two baffle blades and also being rotatable around the center axis, wherein the speed of rotation of the baffle blade assembly and/or the radial dimension of the baffle blades are adjustable to control the screening. The invention additionally relates to pressurized screening devices for implementing the method.

Abstract: A soil rinsing apparatus includes a rinsing and sieving element with two successive sieve regions for rinsing and sieving the soil. Water is supplied in order to reduce the soil to slime and to separate harmful substances from the soil. In order to reduce the water consumption and to improve the soil processing quality fresh water is supplied to the first sieve section and water leaving the first sieve section is collected and fed to the second sieve section which precedes the first sieve section.

Abstract: The pressurized screening device designed for screening fiber pulps, especially paper pulp is provided with a screenplate with perforations, cleaning members being in connection with and moving relative to the screenplate, devices for generating the relative motion between the screenplate and the cleaning members, piping firstly for introducing fiber pulp into the pressurized screening device, secondly for conducting the accepted fiber pulp into the next process stage and thirdly for discharging rejected pulp from the pressurized screening device preferably to be returned into the pressurized screening device, and guiding devices for shifting the flow direction of unscreened fiber pulp to a direction substantially perpendicular to the screenplate. The guiding devices include a combination of several compartments for guiding the flow of fiber pulp which are comprised of side walls, a back wall and baffle blades.

Abstract: A method for keeping a screen surface or a filter surface clean, wherein a pressure fluid is introduced from a conduit to a secondary side of a screen/filter drum, which fluid flows, during an underpressurized stage caused by blades of a rotor rotating on a primary side of the screen/filter drum, through the screen/filter drum from the secondary side to the primary side thereby rinsing the openings of the drum and making them clear.

Abstract: An apparatus for separating different phases of dry material, such as plant fibers, from each other includes a rotating hollow body on an inclined axis with an inner perforated wall, an outer perforated wall, and partitions at spaced intervals within the body to define compartments. The compartments are connected by central openings in the partitions, and each compartment is provided with longitudinally extending baffles. The outer perforated wall is divided into longitudinal sections by a gap. The material is fed into an upper input end and the different phases are separated as it moves within the downwardly inclined body toward an outlet end. The separated phases are carried away by conveyors.

Abstract: In carbon-in-pulp (CIP) and carbon-in-leach (CIL) processes, especially those utilizing pure oxygen instead of normal air to increase the overall efficiency of the cyanide leaching-adsorption process in the recovery of gold and/or silver from ores, the screen within each tank which surrounds the slurry outlet is kept clean. The cleaning action is accomplished by linearly reciprocating the screen first slowly in one direction, and then quickly in another (to cause back flushing); or by rotating a cleaning rotor on the inside of a cylindrical screen. The cleaning rotor may be connected to the same shaft as an agitator disposed above a draft tube within the tank. The screen surface is tapered in its direction of movement, and during movement has a tendency to transport and concentrate the carbon (charcoal) particles at the far end of the slow stroke, and the concentrated particles can be withdrawn and recirculated to other tanks in the system.

Abstract: In screening apparatus for paper making stock comprising a cylindrical screening member dividing the interior of a pressure housing into a supply chamber and an accepts chamber, and also comprising a rotor mounted for rotation in the supply chamber and including a plurality of vanes mounted thereon in angularly spaced relation with each other and in relatively closely spaced relation with the screening member, each of the vanes is of generally airfoil shape and is oriented with its leading edge closest to the screening member and with the surface portion thereof trailing the leading edge diverging from the screening member to create a positive pressure force along the leading edge followed by a negative pressure force between the trailing portion and the screening member.

Abstract: A mixture of two sets of similarly sized particles having different terminal velocities in a separation liquid is separated. This is done by removing either the smaller particle portion of the set having the greater terminal velocity, or the larger particle portion of the set having the lesser terminal velocity, or both, for example, by sieving. The resulting mixture is introduced into a tube in which the separation liquid is flowing upwardly. This eliminates intermixing of the fines of one set with the larger particles of the other set. The flow of liquid in the tube can be arranged to provide laminar flow separated by two regions of turbulent flow to improve separation of particles. Anion and cation exchange resin particles can be separated in this manner, regenerated and returned to service.

Abstract: A sorting apparatus for sorting fiber suspensions heavily laden with rubbish and other contaminants, which sorter has two successive sorting units each having a ring-shaped strainer space, which are likewise successive, and an accepts space with a rotationally symmetric strainer between the accepts space and strainer space. The first sorting unit is pressurized above atmospheric pressure; diluting water is fed to the second unit strainer space; and a rotating plate is mounted between the first and second sorting units to control the flow between the strainer spaces.

Abstract: An improvement for centrifugal sifter units having an elongated sifting chamber having a central axis, a coaxial screen surface therein and a series of paddles mounted on a shaft driven for rotation about the central axis for urging siftable material through the screen surface to separate fines from overs, comprises a series of nozzles mounted on the shaft for rotation therewith. The nozzles are oriented to direct gas streams at the screen surface whereby agglutinating fines are dislodged from each other and are directed through the screen surface. A source of compressed gas is operatively connected to the nozzles. The gas streams may be ionized to further improve throughput.