JP2006508258A - System for separating material carried in a fluid from a fluid carrying particulate matter with the material - Google Patents

Abstract

A system for screening fluid-borne material from a fluid that carries particulate matter along with the material, e.g. for screening usable fibers in papermaking or tissue making white water that also contains waste material such as fines and ash. The system employs a flexible and pliable screen to which the fluid is applied. The screen is supported in a suspended manner from a frame. The fluid is directed onto an inside surface defined by the screen, and the location at which the fluid strikes the screen is varied so as to result in bending and flexing of the screen due to the flexibility and pliability of the screen material. In this manner, the configuration of the screen drainage passages is continuously altered, to provide a self-cleaning action that prevents the screen passages from plugging or blinding over. In one form, the screen is generally frustoconical, and the fluid is applied to the inside surface of the screen in a manner which results in rotation of the screen. The material retained on the screen is directed toward a discharge opening defined by the lower end of the frustoconical screen, and the waste water including the particulate matter passes through the screen and is collected in a waste water collection tank. In another form, the screen is suspended from a frame to form a trough configuration having an open discharge end. The frame is movable in either an axial direction or a transverse direction, to cause movement of the screen and to obtain the desired flexing and bending of the screen to self-clean the screen drainage passages.

Description

  The present invention relates to a method for making products such as paper or tissue from pulp or other fiber-containing materials, and more particularly, recovers usable fibers contained in water produced by such methods. And recirculating methods.

  This application is a continuation-in-part of US patent application Ser. No. 10 / 194,785 filed Jul. 12, 2002.

  In the manufacture of products such as paper or tissue, fiber materials such as wood pulp are used, and the fiber materials are processed in a known manner to produce the desired final product. In the paper or tissue manufacturing process, pulp is poured from a head box onto a screen or paper cloth, water is squeezed from the pulp in a known manner to form paper or tissue, and the paper or tissue is dried And formed into a roll. The water squeezed from the pulp is commonly known as white water and generally contains small particles of fines and ash material that pass through the fabric along with the water. Furthermore, white water necessarily contains a certain amount of usable fiber that passes through or around the papermaking cloth, and the fibers contained in the whitewater are wasted when the whitewater is discarded. This is a recognized problem in the tissue industry and has resulted in the development of a system that recirculates white water back to the pulp supply system to recycle usable fiber. However, such a system also recycles fines and ash material. This can be tolerated in a papermaking process where fines and ash material can be incorporated into the paper. However, the presence of such materials is very disadvantageous in the tissue manufacturing process in that small particles of material interfere with drainage. Thus, a simple recirculation system is not preferred in the tissue manufacturing process, as undesirable fines and ash are simply recirculated through the process. Certain screen systems using stationary screens have been developed to separate usable fibers from fines and ash. Typically, the fibers retained on the screen are manipulated intermittently off the screen and recycled through the pulp supply system. Since such systems inevitably use screens with small openings, there is a significant tendency to clog or “blind over” the screen openings due to the accumulation of material in the openings. Thus, many of the known systems are not functioning properly for this reason, or require much maintenance to protect the screen opening from clogging.

  The object of the present invention is to make paper available to be recycled to the system without recycling undesirable and unusable materials such as fines and ash commonly found in papermaking white water. It is to provide an effective system for recovering usable fibers from white water in the system. Other objects of the present invention include slight modifications to existing papermaking circulation systems, and further allow for the recovery of usable fibers from white water and recycle usable fibers for their use, etc. Is to provide. A further object of the present invention is that little maintenance is required to allow the system to be implemented and operated at a relatively low cost to justify the recovery and recirculation of usable fibers from white water. And providing a system that is relatively simple in parts, configuration and operation. It is a further object of the present invention to replace an ineffective existing collection system with a collection system that provides a clean supply of material to the forming fabric in order to allow more effective operation of the system.

  In accordance with the present invention, a fiber recovery system for a tissue or papermaking process uses a filter or screen, and the white water from the process is filtered or screened at a location downstream of a whitewater recovery container that forms part of the papermaking system. Poured over. The screen is sized so that undesired or unusable white water components such as fines and ash can pass through the screen while retaining usable fibers on the screen. After water containing undesirable or unusable materials is sent to the wastewater treatment facility in a conventional manner, clean water can be re-supplied to the system. The screen into which white water is poured is formed of a flexible and soft screen material, which may be the same type of material commonly used as a fabric in tissue or papermaking systems. The screen is supported in a relatively loose and flexible way, for example by suspending the screen from the frame. The screen is subject to movement as white water is poured over the screen, causing the screen material to flex to provide a self-cleaning action of the screen that prevents clogging and clogging of the screen opening. The present invention contemplates several different devices for supporting the screen and providing motion to the screen and for pouring white water over the screen. In all types, white water is poured into the inner area delimited by the screen, and usable fibers are collected on the inner surface of the screen. The screen is configured to guide the usable fibers to an open discharge area where the usable fibers are discharged from the screen. The usable fibers are then returned to the system and incorporated into the fiber material supplied to the head box for subsequent application to tissue or paper cloth.

Various other features, objects and advantages of the present invention will be made apparent from the following description, taken in conjunction with the drawings. The drawings show the best mode presently contemplated for carrying out the invention.
1-3 are generally designated 30 and illustrate a first embodiment of a fiber recovery system according to the present invention, which is particularly suitable for use in a tissue manufacturing process. In general, the fiber recovery system 30 comprises a screen 32 suspended from a frame 34, which is combined with a white water supply system 38 operable to pour white water from the papermaking system onto the surface of the screen 32 to provide a discharge opening. 36 is configured to partition. The fiber recovery system 30 also includes a fiber recovery container or tank 40 that is disposed below the discharge opening 36 of the screen 32 and opens upward, and a drainage recovery container or tank 42 that opens upward.

  The screen 32 is formed of a flexible and soft screen material and has a truncated cone shape. The material of the screen 32 may be the same as that used as a cloth in the tissue manufacturing process. Typically, the material of screen 32 is a screen material such as model number M-Weave, Duraform, Z-76 available from Albany International, Appleton, Wire Division, Appleton, Wisconsin, With 84 / in (MD), 78 / in (CD) strand count, 730 CFM permeability, and caliper of about 0.4 mm (0.016 inch) A tissue manufacturing screen material with a shed. It is understood that this type of screen material represents various types of screen material that can be used depending on the size of the fiber being recovered and various other operating parameters. For example, the strand size, number, and texture of the screen material may vary from the illustrated embodiment. The operation of the flexible and flexible screen 32 will be described below.

  The upper end of the screen 32 is fixed to the frame 34 so that the screen 32 is suspended from the frame 34. The frame 34 includes a generally circular outer peripheral frame member 44, and the upper end of the screen 32 is connected to the outer peripheral frame member 44. Frame 34 further includes a series of radial spokes 46 extending between outer frame member 44 and hub 48. The mounting member 50 comprises a rotatable shaft 54 that is secured to any satisfactory upper support member 52 and to which a hub 48 is connected. Thus, the frame 34 and the screen 32 are rotatable about a major axis of rotation defined by the major axis of the screen 32 that coincides with the major axis of the shaft 54.

  The screen 32 is configured such that the sides of the screen 32 are positioned at an angle of approximately 30 degrees from the vertical to define an angle that includes approximately 60 degrees. Typically, the screen 32 defines an upper diameter of approximately 122 cm (approximately 48 inches) and is connected to the outer frame member 44, and the discharge opening 36 has a diameter of approximately 18 cm (approximately 7 inches). The height of the screen 32 is approximately 104 cm (approximately 41 inches). These dimensions are believed to provide sufficient throughput to accommodate the amount of white water produced in most tissue manufacturing operations. These dimensions and angles are provided to illustrate one embodiment of screen 32 and frame 34 that has been found to provide satisfactory results, and other dimensions and angles have been found to work satisfactorily. It is understood that For example, the screen 32 may be enlarged to accommodate a large amount of white water produced by a larger amount of tissue manufacturing operations.

  White water supply system 38 is operable to pour white water onto the inner surface of screen 32 from the papermaking process. As shown in FIGS. 1-3, the white water supply system 38 is in the form of a series of upwardly extending conduits 58 that are centered on a major axis that coincides with the major axis of the screen 32. Each conduit 58 includes a series of openings 60 spaced along its length and is closed at the top. Typically, each conduit 58 has an inner diameter of about 7.6 cm (3.0 inches), although it will be appreciated that any other satisfactory conduit size may be used. Conduit 58 extends through bracket 62, which acts to keep each conduit 58 in position with respect to each other. The opening 60 of each conduit 58 is arranged linearly. The rows of openings 60 in each conduit 58 are arranged radially so that the rows of openings 60 in adjacent conduits 58 are oriented in a direction perpendicular to the opposing direction. As shown in FIG. 2, each row of the openings 60 is arranged in a direction parallel to the radius of the screen 32 and in a direction shifted laterally from the radius of the screen 32. Thus, each row of apertures 60 acts to pour white water onto the inner surface of the screen 32 in the direction generally indicated by the arrow 64 (FIG. 2), and the white water impinging on the inner surface of the screen 32 Apply both radial and tangential forces to the. Typically, each opening 60 is circular and has a diameter of approximately 1 cm (approximately 0.375 inches), although any other shape and cross-sectional size may be used.

  The conduit 58 extends through the bottom wall 68 defined by the fiber recovery tank 40 and extends through the bottom wall 70 defined by the white water recovery tank 42. An opening is formed in the tank bottom walls 68 and 70 to provide a passage for the conduit 58 through the tank bottom walls 68 and 70 and a suitable fluid tight seal is provided between the conduit 58 and the tank bottom walls 68, 70. Provided. Also, to avoid the difficulties and maintenance associated with sealing between conduit 58 and walls 68, 70, conduit 58 is routed laterally outward between discharge opening 36 and fiber recovery tank 40. Also good.

  In operation, the fiber recovery system 30 operates to recover usable fiber from papermaking white water supplied through the conduit 58 as follows. White water is poured toward the inner surface of the screen 32 by being discharged through the opening 60 of the conduit 58. Each row of openings 60 forms a series of straight white water shower streams that are poured into the inner surface of the screen 32 in the form indicated generally at 72. The tangential component of the force with which each shower of white water hits the inner surface of the screen 32 acts on the screen 32 to rotate about the major axis of the screen 32 by the rotation of the shaft 54 with respect to the mounting member 50. The rotational speed of the screen 32 depends on the magnitude of the force applied by each white water shower and is proportional to the white water pressure in the conduit 58 and the white water shower flow angle. Typically, it is satisfactory by maintaining a low pressure (eg, about 34 kPa (5 psi)) in conduit 58 that acts to apply a force to screen 32 that rotates screen 32 at a rate of approximately 40 revolutions per minute. It has been found that operation can be obtained.

  The openings in the screen 32 are sized to hold usable fibers on the inner surface of the screen 32 and allow water and waste materials contained in white water such as fines and ash to pass through the openings in the screen 32. It is. The drainage flows to the outside through the screen 32 and falls into the drainage recovery tank 42 by gravity. The drainage may also go down the outer surface of the screen 32. A sheet is provided at the lower end of the screen 32 to pour white water outward into the waste water collection tank 42 as needed. Thereafter, the waste water is sent to the waste water treatment system through the waste water outlet 74 of the waste water collection tank 42, where the solids are removed and clean water can be recycled through the papermaking process.

  Usable fibers contained in the white water are held on the inner surface of the screen 32 and descend on the inner surface of the screen 32 toward the discharge opening 36 by gravity. The layer of usable fiber collected on the inner surface of the screen 32 is typically indicated at 76. As the usable fiber layer 76 descends on the inner surface of the screen 32, the centrifugal force due to the rotation of the screen 32 causes additional water to pass through the opening in the screen 32 as the usable fiber travels toward the discharge opening 36. And act to release waste material. In this way, the usable fiber that is discharged through the discharge opening 36 has a majority of the drainage that is removed from it, and is relatively dense. Usable fibers collected in the fiber collection tank 40 are sent through a fiber discharge port 78 of the collection tank 40 to a pump that recirculates usable fibers in the papermaking process. Also, the fiber recovery system 30 may be installed above the chest level and gravity flow may be used instead of pumping to recirculate the available fibers.

  White water may be poured onto the screen 32 in various other ways, examples are shown in FIGS. As shown in FIG. 4, two supply conduits 58 may be used to pour white water onto the screen 32 instead of the four conduits 58 shown in FIGS. In this case, the opening 60 in the conduit 58 is arranged to be offset with respect to the center of the screen 32 and the radius of the screen in order to pour the shower onto the screen 32 with a tangential force that imparts rotation to the screen 32. FIG. 5 shows another embodiment in which white water is supplied through a single conduit 80 having an elbow tube 82 that applies a tangential force to the screen 32 to impart rotation to the screen 32. To add, provide a radial shift in the shower.

  1-5 illustrate particular embodiments of the present invention, it will be understood that variations of this version are possible and are contemplated within the scope of the present invention. For example, but not limited to, it is contemplated that the rotation of the screen 32 may be performed by the use of a motor to ensure that the screen 32 rotates at a desired speed. In such a variant, the white water shower is poured into the screen, preferably in a radial manner, so that the tangential component of the force applied by the shower is removed. Further, although the screen 32 is shown as having a frustoconical shape with a flat side, it is also contemplated that the side of the screen 32 may have a convex or concave shape, as desired. Is done. It is understood that white water may also be poured onto the inner surface of the screen at any location and in any manner, and the illustrated embodiments are merely representative of various ways in which white water can be poured. Is done. Although the drawing shows the use of four showers to pour white water onto the screen, it will be understood that any preferred number and size of showers may be used.

  The flexibility of the screen 32 allows the screen 32 to deform from its normal shape during operations such as white water being poured into the screen 32. As shown in FIG. 3, the four showers poured into the screen 32 act to bend the part of the screen into which the white water shower is poured, generally protruding in the middle of the outwardly deformed area. A bow-shaped side region is formed. This flexibility and softness of the screen material provides a “self-cleaning” action of the screen, in which the individual strands of the screen occur at the clogging of the screen openings and the “clogging” of the screen. Bend and bend to prevent material accumulation at the corners of the screen opening. Accordingly, the fiber recovery system 30 requires little maintenance and provides a very effective and effective system for recovering usable fibers and separating unsuitable materials.

  FIGS. 6-8 show an alternative embodiment of the fiber recovery system generally similar to the fiber recovery system 30 previously shown and described, and generally indicated at 30 '. Similar reference numerals are used where it is possible to increase clarity.

  In the fiber recovery system 30 ', the screen 32 is suspended from the frame 34 and has the same general structure as described above. In the fiber recovery system 30 ', the white water supply system, generally indicated by the reference numeral 38', has white water in that each conduit 58 'has a lower portion located below the bracket 62 and an upper portion that bends outward relative to the lower portion. Slightly different from the supply system 38. The upper part 83 of the conduit 58 ′ extends in an upward direction and is arranged substantially parallel to the side of the screen 32 so that the flow of white water discharged from the opening 60 is poured in a direction substantially perpendicular to the screen 32. Is done. This arrangement of the conduit upper portion 83 serves to provide a more effective and direct application of white water to the inner surface of the screen 32. Also, white water may be poured onto the inner surface of the screen 32 in a non-vertical direction so that when it hits the surface of the screen 32, the flow of white water includes a force component parallel to the surface of the screen 32. When white water is poured onto the surface of the screen 32 to include a force component that is parallel to the plane of the screen 32, ie, non-vertical, the force component of the white water in the parallel direction is forced to drain the material of the screen 32. , Generally tends to deform from a square or rectangular shape to a diamond shape. This deformation of the discharge pipe of the screen 32 further serves to provide a self-cleaning action of the screen 32 by preventing material accumulation in the corner area of the discharge pipe.

Referring to FIG. 7, each conduit top 83 has two rows of openings 60. One of the rows of openings 60 is arranged to pour a row of white water stream S ₁ directed outward in a radial direction relative to the center of the screen 32. Each conduit top 83 further comprises an additional row of openings 60, the additional rows of openings 60 being bent with respect to the radially facing row of openings 60. The second row of apertures is arranged to emit a series of flow S _2. Each flow S ₂ is arranged at an angle of approximately 45 degrees with respect to the flow S ₁ and strikes the inner surface of the screen 32 to apply a force having both radial and tangential components to the inner surface of the screen 32. Therefore, the flow S ₂ is due to the presence of components of tangential forces, acting to provide rotation to the screen 32. Further, the discharge of two individual streams from each conduit top 83 acts to pour white water into a significant portion of the inner surface of the screen 32 to maximize the surface area of the screen 32 into which white water is poured. To do.

  As shown in FIGS. 6 and 8, the lower portion 85 is fixed to the bottom of the screen 32 by the discharge opening 36. The lower part 85 is fixed to the screen 32 through a skirt 87. The lower portion 85 serves to increase the overall surface area of the screen and delivers usable fiber material inward to the outlet 89 at its lower end surrounding the conduit 58 '. The lower portion 85 may include a series of flaps 91 separated by a slit 93 at the outlet 89. The usable fiber is discharged into the fiber recovery tank 38 through the slit 93. During operation, the fibers are collected on the inner surface of the lower portion 85, and the skirt 87 directs the wastewater outwardly across the fiber collection tank 40 wall to prevent the wastewater from falling into the fiber collection tank 40. Act on.

  FIG. 9 shows an alternative white water supply system 38 ″, which includes a bent upper conduit portion 83, as shown in FIGS. In this embodiment, the white water supply system 38 ″ includes a single supply conduit 95 that extends upwardly in the lower region of the screen 32, and the supply conduit 95 supplies white water to a connecting tube 97 secured to the upper end of the conduit 95. Next, the bent upper conduit 83 is connected to the connecting tube 97 and receives white water from the connecting tube 97 for application of white water through the opening 60 to the inner surface of the screen 32 in the manner described above. In an embodiment, a single tube is required to supply white water to the recovery system, as opposed to the multiple tubes shown in the previous embodiment, which can be used from the funnel 85. To further provide additional control for fiber discharge, the funnel 85 may be formed such that its discharge 89 substantially coincides with the outer surface of the conduit 95.

  9A shows a complete cross-sectional view of the white water supply system 38 ″ shown in FIG. 9 and also shows an alternative system for supporting the screen 32. In the embodiment shown in FIG. 9A, the vertical support in the form of a mast 99 is shown in FIG. 1 and 6, it is arranged inside the screen 32 to rotatably support the screen 32 from below rather than from above, and the mast 99 is supported from the connecting tube 97 by the screen 32. Define a lower end that is mounted so as to face upwardly to the surface defined by the connecting tube 97. The hub 101 is rotatably mounted on the upper end of the mast 99, and the frame 34 is provided by spokes or by any In other satisfactory ways, it is interconnected with the hub 101. With this construction, the fiber recovery system of the present invention generally includes an external support. A self-supporting system that does not need to be manufactured off-site and then easily installed on-site by forming appropriate piping connections with the white water, drainage, and fiber recovery piping of the tissue or papermaking equipment Enable.

  10, 11, 12A, and 12B are generally indicated at 84 and illustrate an alternative fiber recovery system in accordance with the present invention. In this embodiment, the screen 86 is suspended from a frame 88 having an open discharge end 90. White water supply conduit 92 pours paper white water onto screen 86. The fiber collection tank 94 is disposed below the discharge end 90 of the screen 86, and the white water collection tank 96 is disposed below the remaining portion of the screen 86 in the longitudinal direction.

  The frame 88 is generally rectangular in plan and includes a pair of end frame members 98 and a pair of side frame members 100. The screen 86 is made of the same type of material as the screen 32. The screen 86 has a channel or trough shape that defines a closed end 102 and a pair of inclined side walls 104 that converge at the trough bottom 106. The screen 86 is disposed so that the trough bottom 106 is inclined downward in the direction toward the discharge end 90.

  The white water supply conduit 92 defines an outlet 108, and the outlet 108 pours white water in the direction of the arrow indicated by reference numeral 110 on the inner surface of the screen 86. The outlet 108 of the conduit 92 is positioned toward the discharge end of the screen 86, and the pressure of white water in the conduit 92 is at the side wall 104 of the screen 86 where the white water is proximate to the closed end 102 as it is discharged from the outlet 108. It hits the inner surface of the screen 86 and deviates on the closed end 102 and the bottom 106.

  Frame 88 is supported in such a way that frame 88 and screen 86 are movable. In the illustrated embodiment, the frame 88 is supported in a suspension type manner using the cable 112 and ring 114, and then the cable 112 and ring 114 are connected to a suitable upper support 116. As shown in FIGS. 12A and 12B, the frame 88 and the screen 86 are adapted to move in the long axis in an axially back-and-forth manner when white water is poured through the conduit 92 onto the inner surface of the screen 86. Is done.

  During operation, tissue or white paper water is poured through the outlet 108 of the conduit 92 and onto the inner surface of the screen 86 as shown in FIG. The opening of the screen 86 is formed to hold the usable material contained in the white water on the inner surface of the screen 86. Waste water containing unusable materials such as fine powder and ash passes through the screen 86 and is collected in the waste water collection tank 96. As white water is continuously poured onto the inner surface of the screen 86, the screen 86 moves back and forth on an axis intermittently or continuously. Movement of the screen 86 back and forth is performed in any satisfactory manner, preferably in an automated manner by actuation of an intermittently driven motor such as a cam-type actuator or the like. To accomplish this, the frame 96 is pushed backward in the position shown in FIG. 12A and then forwards at its own weight, including the weight of the frame 88, the screen 86, and the material held on the screen 86. Can swing. This movement of the screen 86 accomplishes a number of functions. First, the usable fibers collected in the trough of the screen 86 on the screen bottom 106 and in the lower region of the side wall 104 are ejected when the screen 86 is swung forward as shown in FIG. 12B. Proceed forward toward opening 90. This allows the end portion of the recovered fiber indicated by reference numeral 118 to pass through the discharge opening 90 to supply the fiber recovery tank 94. Furthermore, such movement of the screen 86 bends and deflects the screen material, providing the self-cleaning action described above. The movement of the screen also changes the location where the white water strikes the inner surface of the screen 86 and causes the screen material to bend and deflect locally again to self-clean the screen.

  As usable fiber travels toward the discharge opening 90, water and waste material that is contained in white water and is unfavorable or unusable is continuously separated from the fiber and discharged into the waste water recovery tank 96. The Also, wastewater is sent to a wastewater treatment facility to remove unwanted material and for recirculation to the purified water system. Usable fibers collected in the fiber collection tank 94 are recirculated back to the system through an outlet 120 coupled to the fiber collection tank 94.

  FIG. 13 shows a single conduit 92 arranged to pour white water onto the side wall 104 of the screen 86. As shown in FIG. 14, a pair of conduits 92 ′ are arranged side by side, and even if the straight openings formed in the conduit 92 ′ are spaced apart so as to pour a shower of white water on the side wall 104 of the screen 86. Good things are considered. FIG. 15 illustrates the use of four white water supply conduits 92 ′ to pour a white water shower onto the side wall 104 of the screen 86.

FIG. 16 shows an apparatus similar to FIG. 10 but incorporating a pair of bottom framing members 102 that facilitate forming the recovered fiber material in the region of the bottom of the screen 86.
As shown in FIG. 17, it is also considered that the screen 86 may move to both sides in order to have the same operation as described above. This is also accomplished by applying a lateral force to the frame 88 continuously or intermittently to impart movement to the screen 86. Such movement of the screen 86 acts to rotate the collected fibers at the bottom of the trough defined by the screen 86 to form a fiber roll or log 122. The downward slope of the screen bottom 106 acts to advance the fiber roll or log 122 toward the outlet 90 as the screen 86 moves to both sides.

  FIG. 18 illustrates another alternative embodiment in which the side wall 104 of the screen 86 having an extension 124 is formed. The side wall extensions 124 alternately extend and contract, and the screen side walls 104 alternately lengthen and shorten. In this way, the frame 88 twists around its long axis, while changing the location where the white water strikes the screen 86, deflecting the screen 86 to self-clean and bringing the fiber roll or log 122 to the screen outlet 90. The screen 86 is moved to advance.

  FIG. 19 shows a configuration in which the fiber discharge conduit 126 is disposed at the outlet 90 of the screen 86. In order to stop using the fiber recovery tank 94 and return the usable fibers directly into the papermaking process, the usable fibers traveling towards the outlet 90 are sent directly into the inlet of the fiber outlet conduit 126.

  FIG. 20 illustrates the use of a rigid frame member 126 that is positioned at the outlet 90 of the screen 86. This arrangement acts to form a fiber collection pocket at the bottom end of the screen 86 adjacent to the outlet 90 so as to form a dam from which the collected fiber material is discharged.

  FIG. 21 shows a white water supply conduit 92 having an outlet 108, and the white water stream is discharged through the outlet 108 for application to the inner surface of the screen 86. It is also envisioned that the position at which white water strikes the screen 86 can be changed by changing the position of the flow rather than changing the position of the screen. In this regard, a flow deflector 130 having fins 132 disposed in the white water flow path may be attached to the conduit 92 as shown in FIG. The fins 132 are configured to move in response to white water impingement on the fins 132 such that the white water stream moves so as to be poured toward the screen 86. FIGS. 24A and 24B show a flexible nozzle 134 attached to the end of the conduit 92. The nozzle 134 is formed of a flexible material such as rubber and moves up and down in response to the discharge of white water through the outlet of the nozzle 134 to change the position where the white water impinges on the inner surface of the screen 86. Works.

  FIG. 25 shows a white water supply conduit such as 58 or 92 'having spaced openings 60 to provide a white water shower on the inner surface of the screen such as 32 or 86. The opening 60 is shown as being circular. In order to provide a different shower shape for pouring white water onto the screen, the opening may be a straight transverse groove 136 as shown in FIG. 26 or a V-shaped groove 138 as shown in FIG.

  It will be appreciated that further variations or modifications are possible with respect to the systems and details shown in FIGS. For example, without limitation, the specific shape and configuration of the screen can be varied from the illustrated embodiment. The frame 88 can take any desired shape and can be supported in any satisfactory manner. White water may be poured into the screen using various shown white water supply configurations, or any other configuration desired. Although the screen has been shown and described as being movable in either the axial and lateral directions, it will be understood that a combination of axial and lateral movement may be used. Furthermore, it is understood that the present invention may be used to sort particles carried by any type of fluid and is not limited to use in tissue or papermaking white water sorting applications.

  FIG. 28 shows a typical tissue or papermaking system that incorporates the fiber recovery system of the present invention, indicated at 30 and 84. As shown, the fiber collection systems 30 and 84 are located downstream of the felt pits 152 that collect the white water discharged through the wire pits 150 and the cloth 154. The recovered fiber material is fed to a machine chest 158 through an appropriate feed pipe 160 that feeds the feed for final delivery to the tissue or paper machine head box 162. On the other hand, the recovered fiber is supplied. In order to recover all the usable fibers contained in white water and to wipe out the system of small particle materials such as fines and ash, any number of fiber recovery systems, such as 30, 84, are the size of a tissue or papermaking system. And that it may be used according to the amount of white water produced in the system.

FIGS. 29-33 show exemplary embodiments of materials used to construct the screens 32 and 86. As described above, the screen material may be a tissue manufacturing screen material with five sheds, but it is understood that any other screen material configuration may be used. Screen material includes axial strands S _A and transverse strands S _T woven together in a known manner, the axial strands S _A and transverse strands S _T, generally extending along the thickness of the screen material rectangular Cooperate to partition the drainage opening or pipe C; The screen material is selected so that the dimensions of the tube C are such that the fines and ash material contained in the white water pass through the tube C and the usable fibers contained in the white water can be retained as a fiber layer 7 on the inner surface of the screen material. Is done. As shown in FIGS. 31 and 33, the fiber layer 76 is formed on the inner surface of the screen material, and the region of the fiber layer 76 covering each tube C partially extends into the tube C. The outward formation of the fiber layer 76 in the tube C acts to fix the fiber layer 76 on the screen material. The area of screen material is subjected to outward pressure, such as when the area of screen material passes through the area where the white water shower is located, and the pressure of the white water that is poured separates the individual fibers of the fiber layer 76. In addition, the fiber layer 76 acts as a support for the fiber layer on the screen material that can descend on the screen material toward the screen discharge area. At the same time, the outward pressure applied to the screen material acts to deflect or deform the screen material outward to increase the degree of curvature of the screen material, as described above. Such outward deflection or deformation of the screen material causes the above-described screen deflection action which causes deformation in the shape of the discharge tube C. This results in a self-cleaning action of the screen material, and changes in the shape of the discharge pipe C prevent the accumulation of fines and ash material at the corners of the discharge pipe C. 32 and 33 show this effect. As shown in FIG. 32, fines and particles of ash material P may be applied to the screen, such as between areas where white water showers are poured inside the screen material when the screen material is flat or slightly curved. There is a tendency to be trapped between strands of material. When a white water shower is poured into the screen material, the screen material is deflected outward so that the curvature of the screen material is increased while the inner surface of the screen material and the fiber layer 76 are subjected to the pressure of the poured shower. Such outward deflection of the screen material alters the surface of the strands, and the surface of the strands discharges so as to loosen any particles P that may be trapped in the discharge tube C between adjacent strands. Tube C is partitioned. As shown in FIGS. 32 and 33, the strands of screen material are usually separated by a spacing indicated by A. As the screen material bends, the inner strand moves slightly with the spacing indicated by the symbol A- and the outer strand moves slightly at the spacing indicated by the symbol A +. Such strand movement removes particles from the corners of the discharge tube C and the removed particles are subjected to white water shower pressure, or pressure applied by the shower against the fibers incorporated in the fiber layer 76. And pushing the removed particles outward for discharge from the discharge tube C, either together or separately. This action prevents clogging of the discharge tube C, and thus particles such as code P accumulate between the strands to remove the downtime and excess equipment required to clean the screen equipment required in the prior art. To prevent it.

  After the screen material has moved beyond the outward deflection position, such as caused by the application of a white water shower on the inner surface of the screen, the screen with the fiber layer 76 applied to the inner surface is flat or almost curved. It is thought that it is a shape that has not been done. The fiber layer 76 tends to retain a greater curvature due to the bonding of the fibers when the fiber layer is formed, and thus the flattening of the screen material acts to remove the fiber layer 76 from the screen material. To do. Thus, when the screen material is located between the shower application areas, the fiber layer 76 can move by gravity against the inner surface of the screen material toward the discharge area of the screen.

  If necessary, the screen may sometimes be backflushed, such as by adding air or water to its outer surface, to clean the screen as needed.

  Various alternatives and embodiments are considered to be within the scope of the claims which detail and expressly claim the subject matter of the invention.

The partial cross section side elevation which shows one Embodiment of the fiber collection | recovery system which concerns on this invention. FIG. 2 is a partial cross-sectional view taken along line 2-2 in FIG. 1 showing a stationary screen. FIG. 3 shows the operation of the system and the rotational movement of the screen, similar to FIG. FIG. 4 is a view similar to FIG. 3, showing an alternative device for pouring white water onto the screen. FIG. 4 is a view similar to FIG. 3, showing an alternative device for pouring white water onto the screen. FIG. 2 shows an alternative embodiment of the fiber recovery system of the present invention, similar to FIG. Sectional drawing along line 7-7 in FIG. FIG. 8 is a partial side elevational view of the lower end of the screen associated with line 8-8 in FIG. 6 and incorporated into the fiber recovery system shown in FIG. The expanded partial sectional view which shows the alternative white water supply apparatus for the fiber collection | recovery system shown by FIG. FIG. 10 shows another alternative embodiment of the fiber recovery system of the present invention incorporating a white water supply device as shown in FIG. 9 and is similar to FIG. The isometric view which shows other embodiment of the fiber collection | recovery system based on this invention. Sectional drawing along the 11-11 line of FIG. FIG. 12 is a view similar to FIG. 11, showing the screen undergoing movement for cleaning the screen and for discharging the collected fibers from the discharge area of the screen. FIG. 12 is a view similar to FIG. 11, showing the screen undergoing movement for cleaning the screen and for discharging the collected fibers from the discharge area of the screen. Sectional drawing which shows one Embodiment for pouring white water on a screen, and followed the 13-13 line of FIG. FIG. 14 is a view similar to FIG. 13, showing an alternative embodiment for pouring white water over the screen and imparting motion to the screen. FIG. 14 is a view similar to FIG. 13, showing an alternative embodiment for pouring white water over the screen and imparting motion to the screen. FIG. 14 is a view similar to FIG. 13, showing an alternative embodiment for pouring white water over the screen and imparting motion to the screen. FIG. 14 is a view similar to FIG. 13, showing an alternative embodiment for pouring white water over the screen and imparting motion to the screen. FIG. 14 is a view similar to FIG. 13, showing an alternative embodiment for pouring white water over the screen and imparting motion to the screen. FIG. 12 is a partial side elevational view showing different ejectors for the screen configured as shown in FIG. 11. FIG. 12 is a partial side elevational view showing different ejectors for the screen configured as shown in FIG. 11. FIG. 11 shows the discharge area of a supply conduit for pouring white water onto the screen in the embodiment as shown in FIG. 10. FIG. 22 shows a flow deflector at the discharge of the supply conduit, similar to FIG. FIG. 23 is a sectional view taken along line 23-23 in FIG. 22; FIG. 22 is a view similar to FIG. 21 showing an alternative device at the discharge of the supply conduit for changing the path of white water as it is poured into the screen. FIG. 22 is a view similar to FIG. 21 showing an alternative device at the discharge of the supply conduit for changing the path of white water as it is poured into the screen. FIG. 4 shows different opening shapes for a supply conduit used to pour white water onto a screen. FIG. 4 shows different opening shapes for a supply conduit used to pour white water onto a screen. FIG. 4 shows different opening shapes for a supply conduit used to pour white water onto a screen. 1 is a schematic diagram of a papermaking process incorporating a fiber recovery system of the present invention. 1 is a front view of a screen material used to form a screen that is incorporated into the fiber recovery system of the present invention. FIG. FIG. 30 is a cross-sectional view of the screen material shown in FIG. 29. FIG. 31 is a view similar to FIG. 30 showing a deformed or bow-shaped screen material, such as occurs when white water is poured over the screen during operation. FIG. 31 is an enlarged cross-sectional view of a portion of the screen material as shown in FIG. FIG. 32 is an enlarged cross-sectional view of a portion of the screen material as shown in FIG.

Claims (28)

A system for separating material carried in a fluid from a fluid carrying particulate matter with the material,
A screen device comprising a support and a screen suspended from the support, said screen having a flexibility formed by a series of interwoven strands defining an interior and an outlet and defining a drainage passage Composed of various screen materials,
A fluid supply device configured to pour the fluid outwardly from the interior of the screen onto the inner surface of the screen, the fluid impinging on the inner surface of the screen at one or more impact positions, and A screen is configured to deflect outward at the one or more impact locations, the drainage passage holding the material on an inner surface defined by the screen and the particulate matter passing through the drainage passage. To be large enough to allow
Means interconnected with the support to impart movement to the screen, wherein the movement of the screen occurs when the fluid is poured outwardly onto the inner surface of the screen by the fluid supply device. Changing one or more collision positions;
The outward deflection of the screen as the screen moves past the one or more impingement positions allows the drainage channel to be shaped to remove any particulate matter disposed within the drainage channel. The pressure applied by the fluid supply device at the one or more impingement locations is such that particulate matter passes through the drainage passage to prevent accumulation of particulate matter in the drainage passage. Acting to push particulate matter disposed within the drainage passage. The said support comprises a frame device, said frame device being interconnected with an upper end defined by said screen, said screen defining a lower region located below said unsupported frame device. The system described in. The system of claim 2, wherein the screen defines a conical shape having an upper end connected to the frame device and a lower end defining the outlet. 4. The system of claim 3, wherein the means for imparting movement to the screen comprises means for rotating the frame device about a vertical axis of rotation that coincides with a major axis defined by the screen. The fluid supply device comprises a conduit device disposed in an interior defined by the screen, the conduit device comprising a series of openings, and the fluid is poured through the series of openings onto the inner surface of the screen. Item 5. The system according to Item 4. The system of claim 5, wherein the opening in the conduit device is configured and arranged to exert a force on the inner surface of the screen that tends to impart rotation to the screen about an axis of rotation of the frame device. The system of claim 2, wherein the frame device and the screen are configured to define an upper opening trough having an open end that defines a screen outlet, with the screen suspended from the frame. 8. The system of claim 7, wherein the means for imparting movement to the screen comprises means for changing the position at which the fluid is poured onto the screen. The fluid supply device comprises a conduit having an end, the fluid being drained through the end, the conduit being adapted to change the flow of fluid and the position where the fluid strikes the screen. The system of claim 8, further comprising a discharge member interconnected with the section. 8. The system of claim 7, wherein the means for imparting movement to the screen comprises means for moving a frame device to impart movement to the screen as the fluid is poured over the surface of the screen. . The means for imparting movement to the screen is capable of moving the screen in a direction transverse to the long axis defined by the trough, and the material can be rotated within the trough by lateral movement of the screen. The system according to claim 10. The frame device and the screen define a lower surface where the trough is bent downward, and the lower surface is directed toward the outlet to facilitate the material being directed toward the outlet as the screen moves. The system of claim 11, configured to be guided. The system of claim 11, wherein the screen is movable in an axial direction along a major axis defined by the trough. The frame device and the screen define a lower surface with the trough bent downward, and the lower surface is the outlet to facilitate the useable fibers being directed toward the outlet as the screen moves. The system of claim 13, wherein the system is configured to be directed toward A method for separating a material carried in a fluid from a fluid carrying particulate matter with the material, comprising:
Pouring the fluid onto the surface of a flexible screen, the screen defining a drainage passage sized to hold the material on the surface of the screen, wherein the drainage passage is the fluid A support configured to allow fluid and particulate matter contained therein to pass through the screen, the screen being configured to provide an outward deflection of the screen where the fluid is poured over the surface of the screen. Supported by the device,
Causing the movement of the screen when fluid is poured onto the surface of the screen so as to change the position at which the fluid is poured onto the surface of the screen, in combination with the outward deflection of the screen The movement of the screen can change the shape of the drainage passage of the screen in order to remove particulate matter contained in the drainage passage, and the pressure applied to the surface of the screen by the fluid is within the screen passage. A method comprising: pressing particulate matter in the drainage passage so that the particulate matter passes through the drainage passage to prevent accumulation of particulate matter. The method of claim 15, further comprising the step of recovering the material from a discharge area defined by the screen. The method of claim 16, wherein causing the movement of the flexible screen is performed by changing a position at which the papermaking fluid is poured onto a surface of the screen. The step of changing the position at which the fluid is poured onto the surface of the screen is performed by draining the fluid through a flexible drain member interconnected with a rigid conduit, the flexible drain member being The method of claim 17, wherein an outlet is defined and the outlet is movable in response to discharge of fluid passing through the outlet. The method of claim 16, wherein the step of causing movement of the flexible screen is performed by imparting movement to the screen via a frame device on which the screen is suspended. The screen is configured to define a conical shape having an open lower end that defines the discharge area of the screen, and the frame device is disposed at an upper end defined by the screen to allow the fluid to flow over the surface of the screen. 20. The method of claim 19, wherein the step of pouring is performed by pouring the fluid outwardly from a location within an interior defined by the screen toward an inner surface defined by the screen. 21. The method of claim 20, wherein imparting movement to the screen is performed by rotating the frame device as the fluid is poured onto the inner surface of the screen. The method of claim 21, wherein imparting rotation to the screen is performed by pouring the fluid tangentially to the inner surface of the screen. The screen is suspended from the frame device, the screen and the frame device are configured such that the screen defines a trough shape having an open end that defines the discharge area of the screen, and the fluid is placed on the surface of the screen. 20. The method of claim 19, wherein the step of pouring is performed by pouring fluid into a lateral region defined by the trough shape of the screen. 24. The method of claim 23, wherein the step of imparting movement to the screen is performed by moving the frame device transversely to a long axis defined by a trough of the screen. Defining the lower wall where the trough of the screen bends downwards and positioning the screen so that the lower wall is directed to the open end of the screen to guide and assist the material into the discharge area of the screen. The method of claim 24, further comprising: 24. The method of claim 23, wherein imparting movement to the screen is performed by moving the frame device in an axial direction relative to a major axis defined by the trough of the screen. The trough of the screen defines a lower wall bent downward, and the screen is arranged such that the lower wall is directed to the open end of the screen to facilitate directing material to the discharge area of the screen. 27. The method of claim 26, further comprising a step. A fiber recovery system used to recover usable fibers contained in a papermaking fluid,
Flexible screen means defining an opening and a discharge area, the opening being sized to prevent the passage of usable fibers;
Fluid supply means for pouring fluid onto the surface of the flexible screen means, the flexibility of the screen means preventing the accumulation of fine particles contained in the fluid within the openings of the screen means. The screen means acts to hold usable fibers on the surface of the screen means;
Means for directing the usable fibers on the surface of the screen means towards the discharge area of the screen means in order to be able to release the usable fibers from the screen means for recirculation in the papermaking process And a fiber recovery system.

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