Abstract: A system for monitoring the state of a screen basket of a screen for treating a fibrous suspension includes a cable-free identification unit assigned to the screen basket and disposed in a housing of the screen. An external, in particular mobile, reading unit is provided for the non-contact reading of technical data relating to the screen basket from the identification unit and for producing a connection to a further external database containing data relating to the screen.

Abstract: The invention relates to a strainer for treating a fibrous material suspension suitable for producing a paper, cardboard, tissue, or other fibrous material web, having a plurality of strainer perforations, the smallest cross-sectional areas of which are approximately of the same size. The sorting effect and the throughput are to be improved such that the cross-sectional areas of the strainer perforations on the inflow side have varying size.

Abstract: A screen structure which is unusually effective at removing stickies from recyclable fiber but is tolerant of substantial swings in throughput which result in variations in the flow velocity through the screen-slot velocity. One example of the screen structure is created by forming a very large number of similarly shaped vanes then locking them into a ring structure to form a cylindrical screen basket but equivalent surface configurations can also be formed into sheet stock.

Abstract: A screen basket with replaceable profiled bars and method of making such screen basket are described herein. The screen basket includes profiled bars evenly spaced circumferentially to form a plurality of continuous slots that covers the whole basket length. The profiled bars are fixed in place by a backing structure, including support rings. In pulp and paper industry, this type of basket is mainly used for pulp screening and is commonly referred to as wedge wire basket. As opposed to conventional wedge wire baskets, in which the profiled bars are permanently joined to the rings, the present invention allows replacing the profiled bars when required and to fully re-use the main structural elements. This is achieved with an assembly that allows to insert the profiled bars, preferably consecutively sled into each aligned ring grooves in a vertical movement. The ring grooves are profiled such that there is sufficient clearance for sliding in the profiled bars.

Abstract: A screen basket with replaceable profiled bars is described herein. The screen basket includes profiled bars evenly spaced circumferentially to form a plurality of continuous slots that covers the whole basket length. The profiled bars are fixed in place by a backing structure, including support rings. The support rings are made of at least two sections.

Abstract: The invention relates to a strainer apparatus, such as a strainer basket, a strainer cylinder and the like, wherein slits or gaps are formed between strainer bars (6). The base of the strainer bars is received in receiving recesses (8) adapted to the dimensions of the base of the bars, in a support element (3). The support element can also be a reinforcing or strengthening element, and the strainer bars (6) are permanently fixed to the respective support element (3). At least one pocket (10, 11) that can be filled with a filler material is provided between each support element (3) and each associated strainer bar (6), at least on the edge region (7) of the respective receiving recess (8).

Abstract: A device including a hollow cylindrical body, first and second stationary coaxial annular screening screens disposed within the body, and a rotor within the body and positioned between the screens to conduct the slurry through the first screen and then through the second screen, the rotor being driven in rotation. The pulp slurry passes through a central entry pipe, radially outward and then upward along the inside of the rotor, further inward through a coarse screen cylinder, and then around the end of the rotor to pass between the outer surface of the rotor and the inner surface of a fine screen cylinder. The pulp slurry then finally passes outward through the fine screen cylinder. Coarse rejects, such as knots or other coarse material, are collected at the end of the coarse screening chamber and led away for further processing. Fine rejects are similarly collected at the end of the fine screening chamber, also to be led away separately for further processing.

Abstract: A screen cylinder comprising screen slots (3) and accept channels (8) for directing the portion penetrated the screen slots (3) to an accept side (9) of the screen cylinder (1) of the fiber pulp suspension fed into a feed side (10) of the screen cylinder (1). At least one feed side surface (4) is provided between the screen slots (3) and the accept channels (8) comprise at least one first surface (5) of the accept channel (8) and at least one second surface (6). At least a third of the total length of the accept channel (8) is arranged in a direction opposite to a feed flow direction (A) of the fiber pulp suspension in relation to a normal (19) of a tangent (18) of the screen cylinder (1), which is arranged to pass through the screen slot (3).

Abstract: A screening device for the wet screening of a paper fiber suspension comprising at least one screen plate having a plurality of screen openings, a support structure being detachably attachable to the screen plate, a rotor movable adjacent the screen plate and an outlet opening for a portion of the paper fiber suspension passing the screen openings The support structure of the device is characterized by an outer support ring and an inner support ring and at least one middle support element arranged radially between the inner and outer support rings to support the at least one screen plate. Elastic pre-stressing against the screen plate is generated, and as a result of the elastic pre-stressing, the screen plate exerts compressive forces on at least one radially intermediate support element and respectively exerts tensile forces both on the inner support ring and on the outer support ring.

Abstract: In a cylindrical sieve, a first frame 7 is provided with a first ring plate 7a arranged in a radial direction and a ring plate 7b extended inward in an axial direction X of the sieve from an inner end of the first ring plate 7a. The ring plate 7b has an inwardly warped end. A ring projection 2a is fit in a ring-shaped cavity K1 defined by a ring recess 10a and the first frame 7. The ring plate 7b presses the ring projection 2a outward in the radial direction to prevent the ring projection 2a from being slipped off the matching recess. Through holes 7c (counter bores) are formed in the first frame 7 along the axial direction X. Four of the through holes 7c are used to fasten the rods 6 and receive the Phillips head screws 6f seated therein, and the remaining through holes 7c receives Phillips head screws 20 (see FIG. 1) seated therein for reinforced linkage of the first frame 7 with the holder frame 11.

Abstract: Screening apparatus for screening pulp suspensions is disclosed comprising a screen basket dividing the interior of the housing into a central chamber and a single outer annular chamber. The suspension is supplied to one of the outer and central chambers, so that an accept fraction passes through the screen, while a reject fraction develops that is prevented from passing through the screen. Dilution is provided by supplying diluting liquid to dilute the reject fraction. The screen basket is divided into at least two separate tubular screen sections. The dilution is provided by at least one annular element axially interconnecting the two tubular screen sections and forming a tubular dilution liquid compartment extending at least substantially around the screen basket. The annular element forms a plurality of dilution liquid ejection passages between the dilution liquid compartment and one of the outer and central chambers.

Abstract: In a cylindrical sieve, a first frame 7 is provided with a first ring plate 7a arranged in a radial direction and a ring plate 7b extended inward in an axial direction X of the sieve from an inner end of the first ring plate 7a. The ring plate 7b has an inwardly warped end. A ring projection 2a is fit in a ring-shaped cavity K1 defined by a ring recess 10a and the first frame 7. The ring plate 7b presses the ring projection 2a outward in the radial direction to prevent the ring projection 2a from being slipped off the matching recess. Through holes 7c (counter bores) are formed in the first frame 7 along the axial direction X. Four of the through holes 7c are used to fasten the rods 6 and receive the Phillips head screws 6f seated therein, and the remaining through holes 7c receives Phillips head screws 20 (see FIG. 1) seated therein for reinforced linkage of the first frame 7 with the holder frame 11.

Abstract: The invention relates to a process for size classifying ammonium sulfate crystals using a screen, said process comprising feeding a feed suspension to the screen, said feed suspension comprising said ammonium sulfate crystals in an ammonium sulfate solution, size classifying the ammonium sulfate crystals, and keeping both sides of the screen immersed in liquid during said size classifying.

Abstract: A screen, for cleaning a fiber suspension, includes at least one separating unit containing a housing, a parabolic rotor, a screen basket, an accept chamber, and a reject outlet. The reject outlet is located in the vicinity of the maximum rotor diameter. The screen also includes one or several devices for interrupting the axial flow located in the vicinity of the maximum rotor diameter.

Abstract: A screen cylinder (125) used for screening cellulosic fibrous material pulp in the pulp and paper industry incorporates first (66) and second (67) downstream surfaces (16) having contoured slopes that form a funnel entrance of the grooves (13) at the screen cylinder slots (17). The contoured construction of the screen cylinder (125) effects greatly enhanced utility compared to conventional milled and discrete element screen cylinders, including substantially avoiding the Coanda effect.

Abstract: A method for separating polyester materials from contaminants is disclosed suitable for, for example, a polyester recycling system. The method is a dry separation method and includes rapidly spinning a mixture of polyester and contaminants within a cleaning chamber. During the spinning of the mixture, the contaminants can be degraded and pass through a screen at the chamber wall while the polyester materials are not substantially degraded and can remain in the cleaning chamber. Polyester fines can also remain in the cleaning chamber. A cleaning device suitable for use in the process is also disclosed. The device can include a screen of a hardened material that can help degrade the contaminants and a plurality of rotating blades that can spin the mixture within the device and can also help to degrade the contaminant materials.

Abstract: A screen apparatus includes a tank, a first cylidrical screen disposed inside the tank to form a first chamber, and a second cylidrical screen disposed outside the first cylindrical screen. The second cylindrical screen defines a second? chamber facing the first cylindrical screen and having upper and lower portions communicating with an inlet portion, and second? chamber. A connection member has a groove facing the second? chamber at an intermediate portion of the second cylindrical screen, and a passage communicating with the groove for discharging a paper stock. The paper stock flows to the second? chamber through the upper and lower portions. A part of the paper stock passing through the first and second cylindrical screens is discharged through first and second selection outlet portions, and a part of the paper stock not passing throught the first and second cylindrical screens is discharged through the passage.

Abstract: A the operation of pulp screening apparatus may be improved by employing a multi element foil having a leading foil section and a trailing foil section spaced from and trailing leading section so that adjacent surfaces of the sections one formed by a portion of a pressure side of the leading section and the other by the leading end of the trailing foil section define opposed walls of a passage for fluid directing fluid flow from the pressure side of the leading foil section to a cambered low pressure side of the trailing section. The angle of attack (?) of the complete multi element foil is set to be significantly less than the angle of attack (?) of the trailing foil section to increase the negative pressure pulse generated by the trailing section and thereby improve operation of the screening device.

Abstract: A the operation of pulp screening apparatus may be improved by employing a multi element foil having a leading foil section and a trailing foil section spaced from and trailing leading section so that adjacent surfaces of the sections one formed by a portion of a pressure side of the leading section and the other by the leading end of the trailing foil section define opposed walls of a passage for fluid directing fluid flow from the pressure side of the leading foil section to a cambered low pressure side of the trailing section. The angle of attack (&agr;) of the complete multi element foil is set to be significantly less than the angle of attack (&thgr;) of the trailing foil section to increase the negative pressure pulse generated by the trailing section and thereby improve operation of the screening device.

Abstract: Apparatus for the screening of fiber suspensions is disclosed including a housing, a reject outlet and an accept outlet, a screen located within the housing, a rotor including pulsation wings mounted therein, a reject chamber in the housing for collecting a reject portion of the fiber suspension, and an accept chamber for collecting the accept portion of the fiber suspension passing through the screen and supplying it to the accept outlet, each of the pulsation wings including an outside face and an inside face, a leading edge, a trailing edge, and upper and lower ends so that a predetermined pressure difference is created between the outside and inside faces of the pulsation wings in the direction of the lower edge thereof.

Abstract: Pressurized screen for screening a fibrous suspension that includes intake chamber having an intake to guide the fibrous suspension into the intake chamber, and at least one wire element with a plurality of wire openings. The at least one wire element passes at least a portion of the fibrous suspension in the intake chamber and rejects at least a portion of the fibrous suspension in the intake chamber. A centrifuge rotor with apertures is positioned in the intake chamber so that at least a part the fibrous suspension in the intake chamber travels radially inwardly through the apertures and into the at least one wire element. A heavy material outlet removes at least a part of the fibrous suspension not traveling through the apertures. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: A screening apparatus is used for screening acceptable and rejectable material from a pressurized fiber suspension. The screening apparatus includes a housing, a rotor, a screen basket and at least one sensor. The screen basket is positioned generally concentrically around the rotor, and includes at least one screen element. Each sensor is positioned in association with the screen basket. Each sensor is configured for sensing a wear parameter relating to a wear state of the screen element.

Abstract: A filter media for physically separating particles of an abrasive media having a given mean average particle size from a chemical-mechanical polishing (CMP) slurry. The abrasive media has a particle size distribution including particles larger than the mean average particle size. The filter media is provided as being formed of at least one sheet of a porous membrane having a first and second surface defining a thickness dimension of the membrane therebetween, and having a plurality of generally cylindrical capillary pores formed through the thickness dimension sized effective to capture the particles larger than the mean average particle size. In service, the slurry is supplied to the first side of the filter media, and is passed through the media to the second side thereof such that at least a portion of the particles of the abrasive media larger than the mean average particle size is retained on the first side of the filter media.

Abstract: The invention relates to an arrangement (5) for a filter (6) for plastic material in the form of granulates supplied to an injection nozzle (7), whereby accommodated internally in a casing (8) is a filter body (20) extending in the longitudinal sense of the casing. The filter body (20) consists of metal or some other hard material. Arranged essentially in the longitudinal extent (10) of the filter body (20) is a number of groove-shaped unevennesses (11, 12) in the form of peaks (11) and valleys (12) extending along the filter body on its envelope surface, which unevennesses are executed so as to extend internally within the casing (8) at a distance (S) from it. A gap (9) is formed between the peaks (11) and the casing (8).

Abstract: A screen apparatus of the invention is provided with a tank for receiving a papermaking material; a screen situated inside the tank for dividing the tank into a first chamber and a second chamber to separate a foreign substance from the papermaking material; a first supply passage for supplying the papermaking material into the tank; a second supply passage for supplying the papermaking material into the tank; a stirring member disposed between an inner wall of the tank and the screen to stir the papermaking material introduced in the first chamber; a screened papermaking material discharge passage communicating with the second chamber for discharging a screened papermaking material outside the tank; and a foreign substance discharge passage communicating with the first chamber for discharging a foreign substance outside the tank.

Abstract: Pressure screening apparatus for screening a suspension of paper fiber stock employs a rotor in which a single impulse or foil member is carried or positioned to move along a discrete portion of the screen surface. This arrangement improves efficiency of operation of the pressure screen by reducing the rotational effect of the rotor on the stock suspension being screened and by providing a less disturbed screening region through which the single foil operates. Embodiments are shown in which multiple single impulse elements sweep over discrete portions of a screen and in which a single foil is combined, in screening apparatus, with multiple foils in accordance with the increase in consistency of the stock as it passes through the screen.

Abstract: Pressure screening apparatus for screening a suspension of papermaking stock employing an enclosing housing and a cylindrical screen, with a drum type rotor, has the screen divided or formed with axially spaced annular screening zones and a corresponding number of annular reject collection areas, one for each screening zone. The collection areas are positioned so as to receive rejects from one of the screening zones only, while a rotor is formed with outlet openings that apply stock suspension to selected ones of the screening zones so that there is no mixing of rejects between screening zones, and each screening zone receives stock suspension for screening independently of the other screening zones.

Abstract: A vertical pulp treatment vessel having a top and bottom, such as a continuous or batch digester, has at least a first substantially annular screen assembly disposed within the vessel between the top and bottom. A first substantially annular header is associated with the first screen assembly and first and second withdrawal conduits extend outwardly from the header and are in fluid communication with it. A barrier, such as a radially extending plate, is disposed in the header between the withdrawal conduits, the withdrawal conduits being adjacent each other (typically spaced from each other between about 2-30.degree., e.g. between about 10-20.degree.). A small, compared to the prior art, platform is provided for allowing access to the withdrawal conduits, and automatically controlled valves or like structures in or associated with the conduits, the platform having an arcuate extent of less than 180.degree., typically less than about 110.degree. (e.g. about 90.degree. or less).

Abstract: A de-trashing unit has a rotor fabricated from steel blank. The rotor has two swept blades with blunt leading edges and relieved trailing edges. The rotor is driven to rotate over a trash screen with holes of between one-quarter and one-half inch in diameter. The blade is positioned with a clearance between the blade and the screen of between 0.005 and 0.010 inches. The relieved portions of the blades face the screen while the trailing edges of the blade are tapered between 18 and 30 degrees away from the screen surface. The blade taper creates a strong negative pressure pulse which keeps the screen clear. Holes drilled through the relieved portion of the blade allow circulation through the blade into the region of low pressure generated by the relieved portions passing over the screen. The circulation created by the holes creates microturbulence which keeps a water and paper fiber slurry fluidized.

Abstract: A pressure screen comprises an outer housing with a pulp inlet, and accepts and rejects outlets and an advantageous mount of a stationary screen drum (screen cylinder) in the housing. The screen drum is secured at an upper end flange with bolts to an intermediate ring and supported via the intermediate ring by the housing. A rotating rotor is disposed inside the screen drum. The bottom end of the screen drum is provided with at least one groove with at least one primarily flexible material ring disposed in the groove. Cooperating substantially conical surfaces are provided in the bottom of the screen drum and a bottom intermediate ring, in which the groove is formed.

Abstract: A screen cylinder is adapted to be used with a stirring unit for screening high consistency pulp to be received in the screen cylinder. The screen cylinder includes a plurality of parallel supporting plates, each of which is formed with a plurality of transversely and spacedly arranged mounting grooves. The mounting grooves on one of the supporting plates is aligned with the mounting grooves on an adjacent one of the supporting plates. Each of a plurality of parallel elongated bars has a longitudinal constricted mounting portion to be tightly gripped by the supporting plates in the mounting grooves. Each elongated bar further has a longitudinal head portion on one end of the constricted mounting portion and a pair of longitudinal ribs which extend respectively from opposite sides of the head portion adjacent to the constricted mounting portion. The head portion has a flat end face and an opposite pair of concave side faces which extend inwardly from the end face to a respective one of the longitudinal ribs.

Abstract: Separation and discharge of contaminants and defibration of undefibered waste paper can be effected in a single apparatus which has a generally cylindrical casing, a rotor concentrically arranged in the casing and a cylindrical main screen plate concentrically surrounding the rotor. Stock is separated by the main screen plate into that passing from inside through the main screen plate to outside and that not passing through it. The stock passing through the main screen plate is sent as accept stock to a next process. The stock not passing through the main screen plate is passed through a gap of a defibering section provided by defibration stator and rotor for defibration of undefibered waste paper and is further separated into the stock passing through an auxiliary screen plate and that not passing through it. The stock passing through the auxiliary screen plate is sent back through a circulation pathway in the rotor to inside of the main screen plate.

Abstract: In a method and pressure screen for screening fiber suspension, fiber suspension is passed through two successive screening stages (A, B) provided in the same pressure screen so that accept from the first screening stage (A) is passed to the second screening stage (B), and accept from the second screening stage (B) is removed from the pressure screen. Reject from the second screening stage (B) is returned to the supply side of the first screening stage (A) for rescreening. The pressure screen has a first screen cylinder (9) having an inlet space (V1) into which fiber suspension is introduced. A second screen cylinder (10) is provided at a distance from the first screen cylinder. Accept passed through the first screen cylinder (9) is passed into the inlet space (V5) of the second screen cylinder through a channel within the rotor (3) by pumping blades (5) attached to the rotor.

Abstract: A toner recovering device for an electrophotographic apparatus, which includes: a dust collector connected to a device for cleaning untransferred toner remaining on a photosensitive body; a toner recovering filter having an inlet port for introducing an air-toner mixture from the dust collector side and an exhaust port for filtering the air-toner mixture and discharging the air from which the toner has been removed; a filter mounting section for mounting the toner recovering filter; a joint mechanism having a joint and a hose member, one end of the hose member capable of being connected to the dust collector and other end thereof being joint, the joint being disposed at the inlet port, the joint mechanism being arranged in the filter mounting section in such a manner as to be opened and closed; a detector for sensing that the toner recovering filter has been mounted or not onto the filter mounting section; and a pulling member for coupling the inlet port of the toner recovering filter to the joint in synchron

Abstract: An injection molding compound pellet cleaner 10 removes broken pellets and eliminates excessive dust from molding compound pellets for preparation of the pellets for processing in an automatic molding machine. The pellet cleaner includes a vacuum chamber 22 and a perforated canister 50 for holding the pellets 80. A vacuum is generated within the chamber to clean dust from the pellets and to remove broken pellets.

Abstract: Screening cylinders for screening lignocellulose-containing fibrous material are disclosed. The cylinders are formed from longitudinal bars separated by gaps, and support rings extending around the circumference of the cylinders to support the bars, as well as longitudinal strips whose outer surfaces are a greater distance from the support rings than are the bars.

Abstract: A mesh screen comprising a pair of rings open at each end. A piece of mesh material is releasably clamped between the rings. The inner face of one cylindrical ring is provided with a circumferential groove and a circumferential flange projecting in the same direction as the mouth of the groove. The inner face of the other cylindrical ring is provided with a circumferential flange which is adapted to mate with the circumferential flange of the first cylindrical ring so that the mesh material may be interposed between the flanges, and the free edge of the circumferential flange of the other cylindrical ring is accommodated within the groove.

Abstract: An apparatus is provided for the removal of oversized contaminants from particulate material the is particularly suitable for the removal of contaminants from low density, high surface area particulate materials. The removal of contaminants is accomplished during the transfer of the particulate material from its storage or transport container to a receiving container. The apparatus comprises an assembly having a weir, a trap disposed adjacent said weir, a screen o for separating particulate material from oversized contaminants, a baffle, and an opening through which particulate material will flow freely. The weir has a weir trap flange extending laterally from a weir wall. The trap is configured to capture contaminants if the container to which the assembly is secured is maneuvered to initiate the flow of the particulate material from the container to the receiving container. When so maneuvered, the lowermost portion of the trap in the proximity of the flow of the particulate materials subtends the weir.

Abstract: The invention concerns a sorter with at least two screen baskets in a housing unit. The invention is characterized in that with screen basket diameters of at least 600 mm the at least two screen baskets are contained side by side, spaced, in an arrangement such that their longitudinal center axes extend parallel to each other and their end sides or end surfaces are contained each in identical planes extending perpendicularly to the longitudinal center axes of the screen baskets.

Abstract: An improved efficiency screen plate for screening pulp in a pressure screening apparatus is disclosed wherein various design parameters are established which increase screen performance, particularly in screening medium consistency pulp. The basket is formed of thin, sheet-like material formed without machining into an undulating pattern. Undulation frequencies, slot location, turbulence bar frequency, and turbulence bar height are established for increasing screen performance.

Abstract: A sifter-screening machine for loose material, especially flour, including an inlet for the material, downstream thereof a screen through which the material can be conveyed via an air stream, and downstream thereof an outlet for screened material. Disposed in the conveying route of the material, downstream of the screen, is a zone of reduced static pressure followed in the conveying direction by a conveying zone having an increasing cross-sectional configuration. The weight of the material just upstream of the outlet is at least nearly equal to the oppositely directed pressure of compressed air below an air-permeable element for supplying the material to the outlet.

Abstract: A power plant with a combustion chamber in which a fuel in burned in a fluidized bed of a particular material, comprises a storage container for the bed material which, upon a load reduction, is removed from the combustion chamber. The storage container is provided with a sieve or a grate which prevents slag lumps formed in the bed material from penetrating into a conduit for the return of the bed material to the combustion chamber. A tube projecting into the storage container forms the sieve.

Abstract: A debris catcher comprising a conical screen (filter) in a drill string which defines an annular accumulation space between the screen and the inner wall of the drill string is presented. The central portion of the screen is open to establish an unimpeded flow path. A centrifugal deflector, impeller or similar device above (upstream from) the screen establishes a helical flow pattern in the drilling mud whereby debris entrained in the mud is forced outwardly by centrifugal action. The debris is then caught in the annular accumulation space between the screen and the drill string wall when the mud flows through the screen. If the accumulator fills or the screen becomes clogged, mud will still flow through the center flow passage. The debris catcher of the present invention is preferably positioned within a drill string upstream of a mud powered turbine or other device in the mud stream, the operation of which may be jeopardized by debris in the mud stream.

Abstract: A separator for separating fibers from fines in a flow of gas includes an enclosed housing which includes a cylindrical upper section and a lower section. A screen basket is fixedly mounted in the housing, and this basket defines a screened cylindrical wall, a closed bottom, and an open top. The screen basket is positioned in the housing to define an annular chamber between the upper section of the housing and the screened cylindrical wall of the basket. A first duct is mounted to pass a first flow of gas, fibers and fines into an upper portion of the annular chamber, and is oriented tangentially to cause the first flow to swirl around the screened cylindrical wall. A second duct is mounted to remove gas and fines which have passed through the screened cylindrical wall, and a third duct is mounted to remove gas and fibers which have passed to the lower section of the housing from the lower section.

Abstract: Apparatus for separating relatively large particles from dust particles, comprising an enclosed separating station for separating the large particles from the dust particles. The large particle and dust particle mixture is pneumatically conveyed from a supply source to the separating station. The separated large particles and dust particles are conveyed from the separating station to respective depositories by respective pneumatic conveyors.

Abstract: A classifier for separating into particulate matter relatively coarse and fine particles. The classifier includes a casing, at least one cylindrical screen assembly mounted in the casing and extending substantially in the direction in which the particulate matter flows in the casing for forcing the fine particles to traverse the cylindrical screen assembly, and at least one air purge pipe disposed in the casing for blowing air against the screen assembly to remove particles off the screen assembly, the cylindrical screen assembly and the air purge pipe being relatively movable by a drive mechanism. The cylindrical screen assembly has an increased degree of mechanical strength and rigidity, and provides a wide effective area available for screening.

Abstract: A classifier for separating particulate matter into relatively coarse and fine particles. The classifier includes a casing, at least one cylindrical screen assembly mounted in the casing and extending substantially in the direction in which the particulate matter flows in the casing for forcing the fine particles to traverse the cylindrical screen assembly, and at least one air purge pipe disposed in the casing for blowing air against the screen assembly to remove particles off the latter screen assembly, the cylindrical screen assembly and the air purge pipe being relatively movable by a drive mechanism. The cylindrical screen assembly has an increased degree of mechanical strength and rigidity, and provides a wide effective area available for screening.

Abstract: A classifier for separating particulate matter into relatively coarse and fine particles. The classifier includes a casing, at least one cylindrical screen assembly mounted in the casing and extending substantially in the direction in which the particulate matter flows in the casing for forcing the fine particles to traverse the cylindrical screen assembly, and at least one air purge pipe disposed in the casing for blowing air against the screen assembly to remove particles off the screen assembly, the cylindrical screen assembly and the air purge pipe being relatively movable by a drive mechanism. The cylindrical screen assembly has an increased degree of mechanical strength and rigidity, and provides a wide effective area available for screening.

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: 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