Abstract: A fluid filter comprising a housing defining a fluid inlet and a fluid outlet, a filter element defining an upstream surface communicating with the fluid inlet and a downstream cylindrical surface communicating with the fluid outlet, the filter element comprising a stack of filter disks defining a hollow volume interiorly thereof and a longitudinal axis, and backflushing means for removing filtered out sediment from the filter element comprising an axially displaceable backflushing nozzle assembly disposed within the hollow volume comprising a rotating head coupled to the fluid inlet and having fluid outlet means, arranged to provide a generally radially directed pressurized jet and rotational motion of the rotating head.

Abstract: A self-cleaning pressure filter system including a housing having an unfiltered liquid inlet and a filtered liquid outlet, a filter element of substantially constant cross section having an interior communicating with the unfiltered liquid inlet and an exterior communicating with the filtered liquid outlet for filtering solids from the liquid and wherein filtered out solids are left in the interior of the filter element. A cleaning unit is moved axially along the interior of the filter element and carries at least one radially expansible, substantially annular cleaning member movable in an axial path along the interior face of the filter element for removing solids accumulated thereon. In an least one embodiment of the invention, the radially expansible cleaning member is a split ring circumferentially exhaustible by a spring member. In at least one embodiment of the invention, axial reciprocation of the cleaning member is achieved without need to reverse a rotating member.

Abstract: A screw type dewatering machine according to the present invention includes inner and outer sleeves (1, 2), an annular space chamber (3) defined therebetween, a coil-like screw (4) rotatably disposed in the annular space chamber (3), and drain screens (5, 12) disposed on the inner sleeve (1) and/or the outer sleeve (2), and is characterized in that a support ring (16) is attached to the outer periphery of one end of the coil-like screw (4) and is rotatably supported by the outer sleeve (2).

Abstract: A filter element and a system for cleaning the filter element, including a plurality of layers of fibers arranged in substantially uniform orientation over at least a portion of their active length, along which portion at least, each of the fibers is disposed in close proximity to its adjacent fibers, and a body member constituting a backing surface for the fibers. The system further includes nozzle means for applying at least one fluid jet against the fibers; and means for applying a relative movement between the fiber layers and the fluid jet.

Abstract: A compact sludge dehydrating apparatus having a replaceable upper part, with a lower part, a replaceable upper part having a sludge inlet, a plurality of columns for detachably mounting the upper part to the lower part with a space, a first sludge dehydrator for performing a first dehydration of the sludge waste and being provided in the upper part, a second sludge dehydrator for performing a second dehydration of the sludge waste and being mounted on the lower part. This second dehydrator communicates with the first dehydrator through a pipe. The first and the second cases are interconnected. A plurality of drains is provided to drain the waste waters extruded from the sludge waste as a result of sludge dehydration to a water collection tank of the lower part. The apparatus provides, for the upper part being replaceable for different kinds of the wastes to be treated, which reduces the moisture content of the resulting sludge waste.

Abstract: A sorter with a symmetric screen which is arranged concentrically in an essentially symmetric housing, and in the interior of which there is contained a concentric rotor drum that features on its periphery sorting elements sweeping across the screen, circulating at least parts of the suspension being sorted around the walls of the drum. The sorting elements are of a design such that they will generate a vortex flow of the suspension in the housing. The housing features at its periphery at least one removal duct for heavy contaminants and, in one of its end walls, a central lightweight dirt drain. The housing end wall that features the lightweight dirt drain has, in the direction away from the screen and the rotor drum, from radially outside to radially inside, a diameter that tapers in conic fashion by maximally 11 mm per each 3 mm of axial housing length, and minimally by 2 mm per each 3 mm of axial housing length.

Abstract: A sewage water installation has a discharge basin in which is arranged a screening unit linked to a back-and-forth movable cleaning carriage. The discharge basin (20) is subdivided by a partition (24) and by the screening unit (30) into a storage chamber (25') and an outflow chamber (25"). The storage chamber (25') is linked to an inflow pipe (26) and to an outflow pipe (27) and the outflow chamber (25") is linked to an outflow pipe (28). In order to increase the storage volume and to reduce the throughflow speed, a retaining element (40) is arranged on the back-side of the screening unit (30), as seen in the direction of flow, inclined so as to form an angle therewith.

Abstract: A novel apparatus for isolating solids, slurries or wetcakes from fluids is disclosed. Said apparatus comprises an extruder having a dynamic seal and a barrel comprising a slip joint and a floating auger which allows for solid recovery under pressure in the absence of substantial solvent volatilization.

Abstract: A screw type dewatering machine according to the present invention includes inner and outer sleeves (1, 2), an annular space chamber (3) defined therebetween, a coil-like screw (4) rotatably disposed in the annular space chamber (3), and drain screens (5, 12) disposed on the inner sleeve (1) and/or the outer sleeve (2), and is characterized in thata support ring (16) is attached to the outer periphery of one end of the coil-like screw (4) and is rotatably supported by the outer sleeve (2).

Abstract: A device for separating a mixture comprised of at least a continuous phase I and at least a disperse phase II, one of the phases being a light phase and the other being a heavy phase, comprising canalization means for canalizing a current of the mixture and suited for communicating thereto a helical motion along a central shaft (A) and filtration means, the motion leading to a differentiated radial displacement of the light phase and of the heavy phase under the action of the centrifugal force, during which the continuous phase I flows at least partly through said filtration means. The canalization means and filtration means are arranged to define a helical passage which decreases according to a direction of flow of the mixture through the device.

Abstract: A filter insert for containers, such as tea pots, where a specific dwelling time is required for the filter pulp in the liquid held in the container, the insert consisting of a circular cylindrical filter unit, extending downwards from the top of the container at to least below the surface of the liquid in the container when being filled, and where at least one plunger shaft with a plunger sliding in a plunger guide extends axially through the upper part of the insert.

Abstract: An improved strainer device has a screen which receives a solid/mixture from a feed container for separation. To insure that an uneven flow of the mixture over the screen does not occur due to, for example, a non-level mounting, inlet rushing or turbulence, a weir structure is provided which raises the water mixture level above the screen by a predetermined height.

Abstract: A processing wall is made part of a boundary of a continuous re-entrant lumen, another part of which is a return section. A free, wall conditioning shuttle circulates around this lumen, clearing accumulated material from the processing wall and returning through the return section to circulate again. While the shuttle is in the return section it blocks flow through the return section and while the shuttle is circulating through the processing wall a blocking structure blocks flow through the return section.

Abstract: A self-cleaning gravity screen for removing particulate material from a liquid stream. The screen slopes, and beneath it a rotary wand sweeps against its lower side to keep the screen perforations open and assist movement of retained solids along the screen. The wand is driven by a rotary water wheel.

Abstract: Apparatus for scraping debris from a trash rack occupying a position in a owing stream has a driven, upper turning drum and a pair of chains trained about the drum and carrying scraper blades which engage and carry debris on the upstream side of the rack upwardly for disposal. Each chain is composed of a plurality of links joined at their ends by pivot connections which limit the pivotal movement of the links from positions of linear prolongation in such manner as to avoid the necessity of a lower turning drum. By supporting the chain from an upper drum only, the lower parts of the chain are movable freely in directions away from and toward the rack, as well as vertically.

Abstract: A device for cleaning large quantities of water (3) of rakings at overflow edges (2), especially from rain water reservoirs, rivers, etc., with a stationary separation area (10), which is formed as a section of a cylinder jacket (7) with an axis (8) parallel to the overflow edge, through which the quantity of water flows is provided. A takeover device (11), which is driven about an axis (8) of the cylinder jacket (7), is assigned to the separation area (10) for removing the rakings separated at the separation area (10).

Abstract: An apparatus and a method are provided for separating a feed fluid into a filtrate and a concentrate. A filtrate chamber is divided into several separate filtrate subchambers, each of which is connected to a different portion of a partially permeable wall or membrane to receive that part of the filtrate passing therethrough. A relative motion is induced between the feed fluid and the wall or membrane by a rotating part, thus preventing clogging of the membrane. Sensors are provided in the filtrate subchambers, permitting information about a dynamic separation process to be obtained.

Abstract: A self-cleaning stationary basket strainer has a housing with an inlet adjacent the top and an outlet adjacent the bottom, with a stationary strainer basket contained therein spaced from the wall of the housing. A flush discharge opening and a backwash discharge opening and provided in the closed bottom of the housing. A hollow backwash conduit is provided adjacent the inner surface of the strainer basket, adapted to move about the inner periphery thereof, and has a passage in the wall thereof communicating with a chamber in the conduit. A discharge section on the hollow backwash conduit communicates with the backwash discharge opening in the housing, the backwash discharge opening sealable when not in use. A scraper blade and extension member are provided on the hollow backwash conduit forming a channel which communicates with the passage. A rotatable brush may also be used which moves about the inner periphery of the strainer basket and brushes the inner surface of the strainer basket.

Abstract: A filter including one or more regenerative plates which can be moved along the surfaces of filter grids to simultaneously create turbulence and physically dislodge a filter media cake within the filter by use of an externally extending driver rod, so as to regenerate the filter media.

Abstract: A water intake comprises a common frame and assembled thereto and-forming therewith an integral self-contained unit a pump adapted to be immersed and a trash rake and an associated grid on the suction side of the pump and/or a filter on the discharge side of the pump.

Abstract: A disk-type filter comprising a housing having an inlet connectable to an upstream pipe and an outlet connectable to a downstream pipe, and a stack of filter units disposed within said housing for separating solid particles from a fluid flowing between filter units in said stack of filter units from an upstream side of said stack of filter units to a downstream side thereof, characterized in that said stack of filter units includes a plurality of co-operating filter units defining a plurality of paired co-operating filter surfaces, including first and second surfaces each defining a plurality of fingers, said fingers defined by said first surface being arranged in registration with said fingers defined by said second surface, the exteriors of said fingers defined by said first and second surfaces communicating with either one of an upstream side and a downstream side and the interiors of said fingers defined by said first and second surfaces communicating with the other one of said upstream side or downstream

Abstract: A solid-liquid separator comprising a number of stationary rings arranged with spaces left therebetween, a number of floating rings each disposed movably in the spaces between the stationary rings and a screw conveyor provided in the inner space of the stationary and floating rings. The screw conveyor is driven in rotation to convey sludge water introduced into the space, and while being conveyed, only a water portion thereof is discharged to the exterior through the minute gaps between the floating and stationary rings. The motion of the floating ring prevents clogging of the solid portion in the minute gaps.

Abstract: A method and filter arrangement for filtering particle-contaminated liquid which is caused to spill onto the upper side of a filter 2. Spray pipes 4, equipped with nozzles 5, are rotatably mounted beneath the filter, and spray flushing liquid against the underside of the filter. A drainage channel 7, mounted above the filter surface, catches and directs some of the particle carrying liquid to the outlet 3. The drainage channel has an extended portion which forms a channel inlet and also functions as a splash guard.

Abstract: A screen basket with greater structural integrity and fatigue resistance is mounted within a screening apparatus with substantially no axial compressive loading. The screen basket has end portions attached to a pair of support members with screen basket position engagement elements or fasteners to place the screen basket in a condition with no substantial axial compressive load. The screen basket, supported in this way, remains stationary when exposed to high hydrodynamic torsional forces and reduces the magnitude of deflections and bending stresses placed on the screen basket. The screen basket is preferably mounted in axial tension or with an axial neutral load.

Abstract: A filter medium is provide in a tubular structure configured in the form of a closed loop. Filter maintenance structures mounted on a continuous string lying within the lumen of the tubular structure are continually driven over the surface of a filter medium to maintain an optimum condition of the filter surface. This string with attached filter maintenance structures is driven around the loop of the tubular structure by hydraulic forces generated by the fluid introduced into the apparatus for filtering.

Abstract: A processing wall is made part of a boundary of a continuous reentrant lumen, and wall conditioning runners circulate around this lumen to dislodge accumulated material from the processing wall and thereby continually restore the wall to the condition required for efficient operation.

Abstract: The invention pertains to a device to separate solid materials from a stream of liquid, particularly from cooling water. In the case of the known devices, difficulties occur in cleaning the filter from fibrous contaminants generally or starting with a certain size. The subject device draws off fibrous as well as coarse grained contaminants equally well.A preferably funnel shaped filter 3 with a suction device 4 running at an angle to the surface line 6 of the funnel filter 3 is arranged in a pipe shaped housing. The inclination creates a force component 19 which transports the coarse grained contaminants to the tip of the filter where they are drawn off by the suction opening 8 of the suction rotor 7. The fibrous contaminants are drawn off by the suction device 4.

Abstract: An agitator suction filter for the filtration of fluids containing solids, is provided with a housing with an inlet opening, a bottom cover, a filter plate lying over the bottom cover, with an agitator arranged to rotate over the filter plate, this agitator being provided with an hydraulic lifting and lowering device and with extraction elements which carry or transport the filter cake to an outlet opening, and with an outlet opening and an outlet line which is provided with a shut-off device. Around the agitator shaft is arranged a drive bush which is connected at the external periphery via a drive element to the drive motor and at the internal periphery fixed against rotation to the agitator shaft, with the drive bush being led through a sealing unit and the agitator shaft mounted by the drive bush and movable axially via the lifting and lowering device.

Abstract: A self-cleaning filter including a filter housing having at least a raw-liquid inlet and a clean-liquid outlet, a filter medium interposed between the raw-liquid inlet and the clean-liquid outlet At least one nozzle is located in proximity to the filter medium and is connectable to at least two different sources of pressure, one of which pressures is higher than the pressure prevailing in the filter, the other one being lower than the pressure prevailing in the filter There is also provided an arrangement to produce a relative movement between the filter medium and the at least one nozzle to the effect of having a substantial part of the surface area of the filter medium covered by the nozzle.

Abstract: A manure separating apparatus includes a trough with angularly bottom surfaces that converge downwardly to a discharge opening. A drain screen is located above the bottom trough surfaces and includes somewhat similarly angled downward converging infeed and discharge surfaces. The infeed section of the drain screen is approximately twice as long and at a smaller angle to the horizontal than the discharge screen section. A manure/liquid slurry may be introduced at a top infeed end of the screen and moved downwardly along the infeed section of the screen by a paddle conveyor. Separation of solids occurs primarily along the infeed screen section. The slurry is then moved angularly upwardly along the discharge section of the screen for final dewatering. The discharge section is spaced above the trough bottom to avoid liquids on the trough bottom below to facilitate dewatering of the solids before discharge.

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: A cleanable filter system including a housing defining an inlet for fluid to be filtered and an outlet for filtered fluid, a stack of filter disks disposed within the housing and defining an upstream surface communicating with the inlet and a downstream surface communicating with the outlet and filter disk cleaning apparatus including a plurality of nozzles coupled to a source of backflushing fluid and providing a high pressure stream of fluid impinging on the downstream surface, and apparatus for providing both linear and rotational motion of the plurality of nozzles relative to the downstream surface thereby to result in systematic scanning of generally all of the filter disks.

Abstract: A continuous, low shear solids dissolution system involving a water supply system (100), polymer metering system (120), mixture feed tank (152), mixture pump (154), mixture conduit (172), undissolved polymer dispersal element (188), solution sieve assembly (210), and holding tank (250). The polymer-water mixture (156) is pumped through mixture conduit (172). Undissolved particles of polymer encounter dispersal elements (188) and the particles are more uniformly dispersed. Any particles which are carried undissolved out of the mixture conduit (172) are forced through sieve (214) to further disperse the polymer in the water. The undissolved polymer is completely dissolved by low shear agitation in a holding tank (250).

Abstract: A filtration system for use in a settling tank includes a star shaped filter having equally spaced radial panels with the filter septums forming the downwardly extending sidewalls of each panel or compartment. The framework of the filter allows radial removal of the filter septums for cleaning and maintenance. A unique pressurized wet seal seals the filter to a clean liquid vacuum delivery duct and can also seal the system pump in the settling tank to the vacuum duct.

Abstract: One has aimed at providing a simple, reliable and efficient purification device for the mechanical purification of sewage. At this end, the sewage purification device (1) comprises substantially a strainer pipe (2), which may be designed to be coupled to a sewage pipe (P1), and which is perforated in that portion thereof which, in the position of use, constitutes the bottom portion. The strainer pipe (2) is assigned a water collecting pipe (4) underlying the former in the position of use, extending parallely thereto and, preferably, being sealingly connected thereto, said water collecting pipe (4) being adapted to receive mechanically purified sewage from the strainer pipe (2). The water collecting pipe (4) is open or, respectively, provided with holes, perforations or slots in the portion thereof being opposite to the strainer pipe (2).

Abstract: An apparatus for screening pulp comprises a vessel, a cylindrical screen within the vessel, a rotor moving in the vicinity of the screen at a predetermined speed, an inlet for the unscreened pulp, an outlet for the screened pulp in the vessel. The rotor is non-cylindrical, for instance, elliptical, triangular, and in general, is multi-cam. The rotor has a contour surface which is achieved by attaching bars of the contoured shape to the surface of the rotor, for instance by welding. According to one embodiment, the contour surface of the rotor is discontinuous. The bars form a plurality of spaced protrusions instead of a single protrusion along the entire axial length of the rotor.

Abstract: A self-cleaning filter having an enclosed screen assembly, a rotatable mounted cleaning system located within the enclosed screen assembly, and a propulsion system which causes the cleaning system to rotate is disclosed. The cleaning system and the propulsion system use a frame with a fluid delivery system that is connectable to a pressurized fluid source. Fluid is delivered to propulsion apertures which generate propulsion fluid streams to provide the propulsion for the frame. Fluid also is delivered to a plurality of cleaning apertures which generate cleaning fluid streams that strike apertures in an outer cylindrical surface as the frame rotates. The cleaning fluid streams prevent clogging of the apertures in the outer cylindrical surface ensuring the filters function.

Abstract: A scraper filter system, which comprises a screw-formed spiral impeller within a cylindrical filter element, and a scraper in the groove formed along the spiral end of the impeller for engagement with the internal surface of the filter element for scrapingly removing solid components deposited on the surface of the filter element.The scraper is comprised of a plurality of separate arcuate segments each being urged radially in the external direction by a resilient member, and also includes a securing element for preventing movement of each segment in the groove with respect to the spiral edge of the spiral impeller.

Abstract: A continuous, low shear solids dissolution system involving a water supply system (100), polymer metering system (120), mixture feed tank (152), mixture pump (154), mixture transport conduit (172), undissolved polymer dispersal element (188), solution sieve assembly (210), and holding tank (250). The polymer-water mixture (156) is pumped through mixture transport conduit (172). Undissolved particles of polymer encounter dispersal elements (188) and the particles are more uniformly dispersed. Any particles which are carried undissolved out of the mixture transport conduit (172) are forced through sieve (214) to further disperse the polymer in the water. The undissolved polymer is completely dissolved by low shear agitation in a holding tank (250).

Abstract: An apparatus conveys screenings collected on a bar screen partially immersed in a sewage flow and inclined in the flow direction, and in certain cases on an adjoining apron screen. A rake device conducts the screenings to a discharge position at the upper edge of the bar screen or the apron screen. The screenings are conveyed simultaneously along at least two conveying paths and thus given screenings are transferred along mutually adjoining conveying paths. The rake device includes at least two rake members spaced at intervals in the conveying direction and connected together by a common drive that causes simultaneous translatory movements in the same direction of both rake members.

Abstract: The self-cleaning filter particularly for high-viscosity pasty fluids has a fixed body having a substantially cylindrical elongated chamber in which a filtration drum is supported and defines a central region, at one end of which there is an inlet for the fluid to be filtered, and an outer annular region, at the other end of which there is a duct for the removal of the filtered fluid; a shaft is axially supported and rotationally actuated in the chamber and has a helical crest the profile whereof is suitable for grazing the inner surface of the drum to remove therefrom the impurities which are present and is suitable for pushing the fluid toward an impurity discharge duct arranged at the other end of the chamber, the constant cleaning of the drum being suitable for keeping constant the pressure drop on the filter.

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 drum filter for thickening lime sludge in which the lime sludge is thickened on a filter layer (precoat) formed by the lime sludge on the filter periphery. The filter is provided with high pressure liquid nozzles continuously reciprocating in the longitudinal direction of the drum in such a way that, during each rotation of the drum, part of the filtering layer is continuously detached and drops into a vat containing the lime sludge.

Abstract: An apparatus for screening pulp comprises a vessel, a cylindrical screen within the vessel, a cylindrical rotor moving in the vicinity of the screen at a predetermined speed, an inlet for the unscreened pulp, an outlet for the screened pulp in the vessel. The rotor has a contour surface which is achieved by means of a plurality of protrusions of contoured shape on the surface of the rotor, for instance by welding. The protrusions are spaced and are arranged along the entire axial length of the rotor.

Abstract: An espresso machine is proposed which comprises an espresso-making filter (10) capable of being filled with coffee powder and having a sieve (11, 12) with openings (13) of defined cross-sections for retaining the coffee powder when espresso is being made. Means are provided for varying the cross-sections of the openings (13). These means are preferably configured as needles (21) divided along their lengths into at least two portions of different cross-sections so that the openings (13) formed in the sieve (11, 12) can be closed to a greater or lesser extent depending on the penetration depth of the needles (21).

Abstract: A process for the recovery of coal particles having a maximum dimension of less than 2 mm from coal tailings including the steps of forming a slurry (101) of tailings having a pulp density of from 10 to 30% by weight; feeding the slurry into a hydrocyclone (103) to produce an underflow second stream which contains the tailing particles over a predetermined size and some of the gangue particles smaller than that size and an overflow stream containing the coal particles smaller than the predetermined size and the balance of the gangue particles, the hydrocyclone (103) being operated such that the underflow stream has a pulp density of from 40% to 60% by weight; adjusting the pulp density of the second stream, if required, to from 20 to 50% by weight; passing the repulped second stream over a rapped or vibrated sieve screen deck (105) having a wedge wire sieve screen with a radius of less than 2 m, an arc angle of from 45.degree. to 60.degree.

Abstract: A machine for intercepting solid constitutents in a liquid stream, such as sewage, has a frame which carries a downwardly sloping screen positionable in and across the stream so that the liquid flows through but the outer side of the upwardly and forwardly sloping screen intercepts solid constituents. The screen has a stationary grate with parallel grate bars extending from the lower to the upper end of the screen, and a mobile grate with parallel grate bars which alternate with the grate bars of the stationary grate. The mobile grate is repeatedly movable forwardly of the stationary grate to lift off the stationary grate bars those solid constitutents which were intercepted by the two sets of grate bars, and the mobile grate is then moved upwardly to raise the lifted solid constituents along the outer side of the stationary grate prior to redepositing the lifted constituents on the stationary grate.

Abstract: A backflushable filter including a housing having an inlet coupled to an upstream fluid inlet and an outlet coupled to a downstream fluid outlet, a filter assembly including a plurality of cylindrical filters, defining an upstream surface communicating with the inlet and a downstream surface communicating with an axial hollow volume therein, the axial hollow volume communicating with the outlet, a backflushing assembly comprising a backflushing nozzle disposed in each axial hollow volume for backflushing engagement with each of the cylindrical filters at its downstream surface, and a backflush drain communicating with the upstream surface.

Abstract: Improved bar screen raking systems are provided with telescopical boom members, forming the rake arm controlling displacement up and down, in combination with a hydraulic piston rod cylinder, controlling displacement in and out. In one embodiment the raking system includes a telescopical rake arm boom comprising a boom member supporting a bearing slide and ball carrier, a cam follower and track arrangement in fixed spaced apart parallel disposition on opposing sides along the length of said boom, a boom side member connected to said bearing and cam arrangements for carrying a rake, a hydraulic piston driven cable device fixedly supported by said boom and parallel to said bearing slide and cam follower arrangements for controlling boom displacement up and down and a hydraulic piston rod cylinder device for controlling boom displacement in and out.

Abstract: A cylindrical screening basket for sorting and classifying fiber suspensions includes a wall which has an inner wall surface facing the fiber suspension and is provided with screen openings which lead into grooves arranged at the inner wall surface. The grooves extend essentially parallel to each other and transversely to the flow direction of the fiber suspension and are arched to define a downstream flank and an upstream flank, with the downstream flank having a sharper curvature than the upstream flank.