Abstract: The invention concerns the short circulation of a paper or board machine and in particular a simplified process arrangement for the short circulation, which arrangement comprises a metering system (20) for the stock (M) or stocks, pumps (110, 130, 170), a headbox (150), and a wire part (160) as well as a pipe system interconnecting the devices, with means of regulation, and in which arrangement a high-consistency stock (3) is fed into the headbox (150), and the white water (4) recovered from the wire part (160) is fed by means of a diluting pump (170) into the headbox (150) so that diluting of the stock suspension is carried out in the headbox.

Abstract: Apparatus and process for guiding portions of backwater produced or stored at different levels of a machine. The apparatus includes an upper backwater chamber arranged to receive first backwater, a lower backwater chamber arranged below the upper backwater chamber and to receive at least a portion of the first backwater from the upper backwater chamber. A plurality of hydraulic lines are arranged to couple the upper backwater chamber to the lower backwater chamber, and inlet openings of the plurality of hydraulic lines are arranged inside the upper backwater chamber and are arranged at different geodetic heights relative to one another. The process includes collecting first backwater in an upper backwater chamber, and guiding the first backwater from the upper backwater chamber to a lower backwater chamber through inlet openings to a plurality of hydraulic lines. The inlet openings are arranged at different geodetic heights relative to one another.

Abstract: The invention relates to a method and a device for degassing of suspension, specifically fiber stock suspension. The method according to the invention is characterized in that separated excess suspension is discharged sideways through an overflow having an overflow edge that is located in the tank outside wall and is positioned parallel to the tank axis. The device according to the invention is characterized in that the overflow includes at least one overflow having an overflow edge that is located in the tank outside wall and is positioned parallel to the tank axis and that at least one overflow system, for the purpose of discharging the separated excess suspension, is located following the overflow.

Abstract: An arrangement for handling white water from a paper machine comprises a white water channel having an inlet end for receiving white water from a paper machine and an opposite outlet end defining a main outlet through which the white water is discharged into a container. A channel bottom slopes downward and an additional outlet is provided between the main outlet and the inlet end, the bottom having a first bottom portion that leads away from the inlet end up to the additional outlet and a second bottom portion that leads away from the additional outlet toward the main outlet. The first and second bottom portions are so arranged in relation to each other that each of the bottom portions slopes downward in the flow direction at an angle of inclination that exceeds a critical angle of inclination that avoids sedimentation on the bottom.

Abstract: Backwater cycle of and process for circulating water in a paper machine having a wet zone. The backwater cycle includes at least one application device arranged to apply a composition containing at least one of pigment and filler onto a fiber web in the wet zone, a first backwater cycle that supplies a stock inlet with backwater removed from the production process upstream, relative to a web travel direction, of the at least one application device, and a second backwater cycle that accepts a remainder of the backwater. The process includes extracting backwater from the fiber web, and feeding backwater, which is not charged with the at least one of pigments and fillers, to a stock inlet.

Abstract: Process and device for the mixing of suspensions with possibly different natures and/or compositions in the stable section of a paper machine. In the process, a suspension, particularly of the backwater of the paper machine, is piped in a mixing tube with the main flow direction in the longitudinal direction of the tube, and additional suspensions, with possibly different solid content, are injected. In the device, a mixing device and piping carry the suspension in the stable section of a paper or cardboard machine and blend suspensions with a higher solid content into a first suspension with little or no solid content. The mixing device and piping include a tube, at least one inlet for the first suspension, a plurality of feeds for the higher solid content suspensions to be admixed, and one outlet for the blended suspension, with a new solid content, arranged downstream from a bend in the tube.

Abstract: In a method and an associated apparatus for discharging the whitewater from inside the loop of a continuous dewatering wire of a former, specifically a twin wire former in a paper machine the accumulating whitewater is collected by a collection tank, which is located within the loop; the collected whitewater is separated from the air, still inside the loop, by suctioning off of the area above the collection tank and the whitewater is removed from the collection tank through at least one channel that is connected to the collection tank and is located below the collection tank's water level.

Abstract: Apparatus is disclosed for handling a web including a pair of juxtaposed press rolls providing a nip therebetween, a coarse shredder trough disposed above the nip to receive the web from the nip, and a doctor arrangement for transferring the web from the outer surfaces of the press roll including a doctor support extending longitudinally of the pair of press rolls and a plurality of doctor blades attached to the doctor supports and extending in abutment with the outer surfaces of the press rolls, the doctor arrangement being supported by the coarse shredder trough whereby the doctor blades form a rigid structure for the plurality of doctor blades.

Abstract: A system for removing bleed-through contaminants from OCC fiber pulp includes a plurality of primary flotation cells, with each primary flotation cell having an inlet, an accept outlet and a reject outlet. The inlet and the accept outlets of the plurality of primary flotation cells are coupled together in a series configuration. The reject outlets are coupled together in parallel. A secondary flotation cell has an inlet, at least one accept outlet and a reject outlet. The secondary flotation cell inlet is fluidly coupled with the reject outlet of the primary flotation cells. A water clarifier has an inlet, a clarified water outlet and a sludge outlet. The inlet is connected with the reject outlet of the secondary flotation cell.

Abstract: A method and apparatus in which fibrous waste is processed under initial over-pressure conditions is disclosed. Once the fibrous waste has been loaded into an autoclave, a compressor pressurizes the chamber, following which caustic swelling and debonding solution is injected into the chamber. In a further embodiment, a caustic solution is introduced into the fiber slurry output from an initial separation stage, following which negative pressure is maintained for a period of time chosen to enhance the desired debonding. In yet another embodiment of the present invention, de-inking solution is introduced into an initial fibrous waste processing stage which operates at super- or sub-atmospheric pressure.

Abstract: An improved process for the separation of cellulosic fiber from difficult to process coated and inked paper products is disclosed and claimed. This process readily separates the paper pulp fraction substantially free of contaminants from such waste paper products as single and two side polymeric coated board having wet strength resin, single and two side polymeric coated board having no wet strength resin, single and two-sided glossy printer trimmings, ultraviolet (UV) cured ink coated stocks, and mixtures thereof. Preferred embodiments include a process in an inclined pressure vessel equipped with agitating and rotating means operative to reflux the waste material with respect to the inclined axis of the vessel in the presence of steam and chemical aids for a sufficient period of time so as to bring about repulping and separation of the paper fiber fraction and formation of a contaminant-collecting polymer phase.

Abstract: An apparatus for degassing an aqueous suspension containing pulp fibres, the apparatus comprising an elongated horizontal reservoir and a bypass manifold extending into the reservoir. The bypass manifold is placed inside the reservoir such that it it positioned substantially within the aqueous suspension at the bottom of the reservoir, the manifold thus decreasing the flow cross-sectional area of the aqueous suspension at the inlet end of the bypass manifold (2) in the reservoir.

Abstract: Apparatus and process for producing foam formed fibrous web in which the furnish is made up by mixing a thin water slurry of fibers at a consistency in the range of from about 0.5 to about 7 weight percent fibers with sufficient aqueous foam containing a surfactant and having an air content in the range of from about 55 to about 80 percent by volume to form a foamed fiber furnish containing from about 0.1 to about 3 weight percent fibers which is supplied directly to the forming felt or wire of a twin wire papermaking machine, adding makeup surfactant and discarding excess aqueous foam from the process as required to maintain the desired volume of foamed liquid therein.

Abstract: The invention relates to a method of recovering energy in a forming section of a papermaking or boardmaking machine, wherein stock from a headbox is fed into a forming zone of a forming section, said forming zone including at least one looped forming fabric curving along a convex surface of a support member, and water is drained from the stock through said at least one forming fabric in the forming zone to form a paper or board web, the water passing through said at least one fabric being thrown out from the forming zone and possessing kinetic energy, characterized by placing a movable component in the water thrown out from the forming zone, so as to cause the water to move the component, and thereby recovering part of the kinetic energy. The invention also relates to an arrangement in a papermaking or boardmaking machine.

Abstract: The invention concerns the short circulation of a paper or board machine and in particular a simplified process arrangement for the short circulation, which arrangement comprises a metering system (20) for the stock (M) or stocks, pumps (110, 130, 170), a headbox (150), and a wire part (160) as well as a pipe system interconnecting the devices, with means of regulation, and in which arrangement a high-consistency stock (3) is fed into the headbox (150), and the white water (4) recovered from the wire part (160) is fed by means of a diluting pump (170) into the headbox (150) so that diluting of the stock suspension is carried out in the headbox.

Abstract: An arrangement for handling white water from a paper machine comprises a white water channel having an inlet end for receiving white water from a paper machine and an opposite outlet end defining a main outlet through which the white water is discharged into a container. A channel bottom slopes downward and an additional outlet is provided between the main outlet and the inlet end, the bottom having a first bottom portion that leads away from the inlet end up to the additional outlet and a second bottom portion that leads away from the additional outlet toward the main outlet. The first and second bottom portions are so arranged in relation to each other that each of the bottom portions slopes downward in the flow direction at an angle of inclination that exceeds a critical angle of inclination that avoids sedimentation on the bottom.

Abstract: A sample collecting device takes samples from the white water drained from the web through the wire in the wire part, at a number of points in the cross direction of the web. An analyzer analyses the samples and forms a retention profile for controlling the paper machine. The device for measurement and regulation of the retention profile comprises means for measurement of the retention profile across the web width from different points of width of the web. The headbox comprises ducts passing to different points of width of the headbox to pass a flow of liquid containing a retention agent in the headbox into connection with the stock flow to regulate the retention profile across the web width. The ducts have valves which are regulated on the basis of the retention profile data for regulating the retention agent into duct flow.

Abstract: Apparatus for transferring at least a portion of a running web from a first section of a web making machine to a second section of the web making machine includes at least two pulleys, in which at least one is a driven pulley, a suction box coupled to a vacuum source, an air-pervious endless conveyor belt tensioned over the at least two pulleys to form a conveying run and a return run, and a device for creating a negative pressure at an inner surface of the conveying run. The at least one driven pulley is adapted to drive the endless conveyor belt over the at least two pulleys while the negative pressure propagates through the conveying run. The endless conveyor belt includes an upstream and a downstream end and the endless conveyor belt is pivotable around a pivot axis located in a region of the upstream end. The endless conveyor belt is pivotable to move the portion of the running web between the rope section and the portion is adapted to receive a full width of the running web.

Abstract: A shoe press roll for dewatering a fibrous web in machines for at least one of producing and processing a fibrous web is provided, including a flexible roll jacket having a profiled surface for water absorption. At least one press element is provided, having a concave pressing surface, arranged against a cylindrical mating roll to form a concavely bent press nip for pressing said flexible roll jacket. A continuous dewatering belt is positioned at least between said shoe press roll and the fibrous web for absorbing pressed-out water, being guided off of said roll jacket after the press nip. A water collection device is arranged for collecting and removing water spinoff from said roll jacket said water collection device being positioned between said shoe press roll and said dewatering belt, and as close as possible behind the press nip, relative to a belt travel direction.

Abstract: The invention relates to a method of recovering energy in a forming section of a papermaking or boardmaking machine, wherein stock from a headbox is fed into a forming zone of a forming section, said forming zone including at least one looped forming fabric curving along a convex surface of a support member, and water is drained from the stock through said at least one forming fabric in the forming zone to form a paper or board web, the water passing through said at least one fabric being thrown out from the forming zone and possessing kinetic energy, characterized by placing a movable component in the water thrown out from the forming zone, so as to cause the water to move the component, and thereby recovering part of the kinetic energy. The invention also relates to an arrangement in a papermaking or boardmaking machine.

Abstract: Mixing and recirculation cycling system and method, for use in the stable section of a paper or cardboard machine. The system includes a dilution water-regulated headbox, a backwater tank having a backwater inlet and at least one stock suspension inlet adapted to provide for the mixing of stock suspensions with the backwater. Also provided is a mixing tank operatively connected to the backwater tank, at least one backwater inlet operatively connected between the backwater tank and the headbox, and a pressure-increasing device operatively connected between the mixing tank and the backwater tank.

Abstract: Water draining device for a paper machine or the like, in particular for a felted press of such a paper machine, including a receiving tank extending at least essentially over the machine width. The receiving tank includes a first chamber that receives arriving water and is under ambient pressure, and a second chamber that is connected to the first chamber and is under vacuum, into which the water collecting in the first chamber is aspirated and from which the water is eventually drained. A water receiving device of improved efficiency is also provided by forming a water receiving device by at least one suction channel projecting into the wedge-shaped area between the upper press roll and the dewatering belt, and extending transverse to the pulp web, which suction channel is connected to a source of reduced pressure.

Abstract: A process arrangement for the short circulation in a paper or board machine including stock chests for component stocks, metering pumps for component stocks, cleaning devices, pumps, a headbox and a wire section as well as a system of pipes connecting these elements, together with regulation devices. After the metering pumps, the component stock flows are passed into a closed mixing volume in which the component stocks are mixed and diluted with a first dilution water flow. From this closed mixing volume, the stock is passed in a closed space by a first feed pump of the main line of the process through a screen and a centrifugal cleaner to the suction side of a second feed pump of the main line, where a second dilution water flow is passed to the stock. The second feed pump feeds the stock through a machine screen to the inlet header in the headbox.

Abstract: A paper machine and web control system for the same to be activated on web rupture, which paper machine has a double-felted press nip and a treatment unit for increasing the dry solids content of the web downstream of the press nip, the web being transferred from the press nip to the treatment unit in an open draw. The web control system has a water-application device arranged at the open draw to discharge jets of water against the upper press felt on rupture of the web so as to prevent an upstream end of the web continuing with the upper press felt, a felt-deflection device situated downstream of the press nip to bring the press felts into contact with each other downstream of the press nip on rupture of the web so as to sandwich the web between the felts, and a suction device in the loop of the lower press felt at a position between the press nip and the felt-deflection device to temporarily attach the web to the lower press felt by suction.

Abstract: A nonwoven web of fibrous material is made by the foam process using a manifold of a particular construction. The manifold has a casing with first and second opposite ends including an inlet for a foam-fiber-surfactant slurry at the first end, and optionally a valved outlet at the second end. A center section of the manifold casing has a (e.g. rectangular) cross-section that becomes smaller moving from an inlet toward the outlet. First and second substantially closed side walls, a porous front wall having an effective length, and a back wall opposite the front wall, are provided for the center section, the walls planar or curved. Any suitable structures are provided for introducing a second (e.g. substantially fiber-free, or a fiber-foam slurry) foam into the center section through the back wall.

Abstract: A single plant for making corrugated sheets out of recycled paper and a method for making the same. The plant includes a recycling pulper a board machine and a corrugator.

Abstract: The invention refers to a process for regulating a screw press, particularly for dewatering a pulp suspension. It is mainly characterized by the speed being varied as a function of the torque.

Abstract: Process for cleaning or maintaining the cleanliness of a low-consistency branch of a stock density-regulated headbox system including a constant part of a paper or cardboard machine having at least one high-consistency branch and one low-consistency branch, possibly sectioned. The final concentration output by the headbox onto a wire or between two wires is determined by a mixing ratio of high-concentration and low-concentration suspension flows. The process includes supplying the low-consistency branch with an increased content of solid particles. Headbox system including a constant part of a paper or cardboard machine, having a stock density regulation that is sectioned across the machine width by variably mixing a high-consistency suspension and a low-consistency suspension, with a high-consistency branch and a low-consistency branch. The headbox system includes at least one supply to the low-consistency branch for introducing solid particle contents into the suspension flow.

Abstract: Method for regulating the surface level and the consistency in a stock chest for metering of a component stock. Stock is fed as an outward flow out of the bottom portion of a storage tower by a first pump into the stock chest. Into this outward flow, a first dilution water flow is passed in order to regulate the consistency of the stock fed into the stock chest to a—desired level. The stock is fed as a metering flow from the stock chest by a second pump into the short circulation of the paper or board machine. The surface level in the stock chest is maintained constant by an overflow passed from the stock chest (20) into a pumping tank. From the pumping tank, stock is fed as a return flow by a third pump into the bottom portion of the storage tower. A second dilution water flow is passed into this return flow to thereby regulate the consistency in the bottom portion of the storage tower to a desired level.

Abstract: Process and device for the mixing of suspensions with possibly different natures and/or compositions in the stable section of a paper machine. In the process, a suspension, particularly of the backwater of the paper machine, is piped in a mixing tube with the main flow direction in the longitudinal direction of the tube, and additional suspensions, with possibly different solid content, are injected. In the device, a mixing device and piping carry the suspension in the stable section of a paper or cardboard machine and blend suspensions with a higher solid content into a first suspension with little or no solid content. The mixing device and piping include a tube, at least one inlet for the first suspension, a plurality of feeds for the higher solid content suspensions to be admixed, and one outlet for the blended suspension, with a new solid content, arranged downstream from a bend in the tube.

Abstract: A headbox for a paper machine and a process for controlling consistency of the slurry. The headbox includes a turbulence insert having an inlet end and a distributing pipe having a connecting area. The distributing pipe may extend across a width of the paper machine for feeding a slurry flow through the connecting area and into the turbulence insert. The headbox may also include a nozzle having an outlet gap and a plurality of feed lines supplying control flows. The plurality of feed lines may be coupled to the connecting area at an angle .alpha. between approximately 5.degree. and 170.degree. with respect to a directional component of the slurry flow directed toward the turbulence insert, the plurality of feed lines may be positioned in a vicinity of the inlet end.

Abstract: A method for producing surface-treated paper, in particular of fine paper, and a dry end of a paper machine that makes use of the method. A paper web that has been dewatered by pressing is dried in the forward dryer section, in which drying energy is applied to the paper web over the entire length of the forward dryer section asymmetrically in the z-direction from the side of the bottom face of the web. This step is carried out by a number of successive groups with single-wire draw that are open downward. In this manner, shrinkage of the web both in the machine direction and in the cross direction is reduced or at least partially prevented, which shrinkage tends to take place when the dry solids content becomes higher. Paper broke is removed from underneath the drying groups that are open downward substantially by the force of gravity onto the broke conveyor placed underneath.

Abstract: An improved double acting deaeration vessel is most desirably used in the pulp and paper industry. The deaeration vessel removes gas from a fiber suspension without requiring fine adjustment of the final consistency of the suspension fed to the deaeration vessel. In the same gas volume where the fiber suspension is treated in the deaeration vessel a second partition wall forming a second weir is provided, and the vessel jacket is provided with one or more inlets for a second fluid medium to be introduced into the vessel, with an outlet for the substantially gas free second fluid medium. A common outlet is provided in the common gas volume for gas separated from both the fiber suspension in the second fluid medium, as well as an outlet for the fraction of the second fluid medium separated by the weir.

Abstract: An apparatus for improving retention of filler in papermaking systems includes a split stream feed to either the head box or fan pump of a papermaking system. The split stream divides the pulp flow into two streams, one stream having a retention aid and filler added thereto. The retention aid and filler-containing stream is then added back to the other stream upstream of the fan pump or head box. Treating only a portion of the overall pulp flow with the filler/retention aid lowers retention aid consumption, improves paper product appearance and maintains or increases filler retention during papermaking.

Abstract: A paper-making machine includes a wet end associated with a wet fiber web, a headbox having an outlet gap, and a forming fabric positioned adjacent to the outlet gap and moving in a direction of web travel. An air/water separator is positioned in association with the forming fabric and downstream from the headbox relative to the direction of web travel. The air/water separator is configured for receiving liquid from the fiber web. A blower having a housing and an impeller is fluidly connected with the air/water separator. The impeller is rotatably carried by and within the housing and has a rotating hub with a periphery. The impeller also has a plurality of vanes attached to and extending from the hub and substantially equally spaced around the periphery. The vanes are formed of a non-metallic, composite material and have a coating of a layer of hydrophobic material substantially covering the composite material.

Abstract: A wet part of a paper making machine includes a distributor to which a main stream of a stock suspension is fed and which has a number of connections. The connections are connected by means of split stream lines to a machine-wide flow box which has a machine-wide slice nozzle (headbox). The split stream lines are connected (directly or indirectly) to the flow box. The slice nozzle is connected to at least one continuous web-forming screen. At least one collection trough is connected to the screen, as well as, optionally, to a backwater tank to accept the backwater trapped by the collection trough. Dilution water lines are provided to introduce backwater into the split stream lines to adjust the stock density of the split streams. The dilution water lines are connected directly to the collection trough.

Abstract: A combination blowbox/saveall system (20) and method for use in conjunction with a pick-up roll (22) of a papermachine (18) around which a carrier fabric (26) and running web (28) are moved in concert utilizes a blowbox section (40) for directing air from a source generally away from the surface of the carrier fabric opposite the web to reduce the likelihood of separation of the web from the carrier fabric and a saveall section (60) joined to the blowbox section in a single device. During operation of the system, at least a portion of the air which is directed away from the carrier fabric by the blowbox section for the purpose of preventing separation of the web and fabric downstream of the pick-up roll is used to dislodge water droplets (72) and other contaminants from the surface of the pick-up roll, and these droplets and contaminants are collected within the saveall section for disposal.

Abstract: A method of papermaking having zero liquid discharge. A cellulosic pulp composed of recycled materials is initially cleaned to remove contaminants and foreign material, and the clean pulp is then washed to remove dissolved solids and pulping chemicals, and the washed pulp is then utilized in the papermaking process. The contaminants are separated from the liquid residue resulting from the pulp cleaning operation, preferably by floatation clarification, and the effluent from the clarification is evaporated to produce steam or water vapor along with an evaporated residue. The evaporated residue is combined with the suspended solids that were removed from the liquid residue and the combined residue is then subjected to a mechanical dewatering operation to reduce the water content so that the dewatered material can then be either landfilled or incinerated. The condensate from the evaporation can be combined with fresh makeup water and used in the papermaking process.

Abstract: In a method of recovering fibers from white water using a filter including a vat and a rotating filter surface (such as a disc filter), auxiliary pulp is supplied to the area of the vat where the cleaned and rotating filter surface meets the pulp surface in the vat. The consistency difference in the filter vat is adjusted by controlling the auxiliary pulp flow, or by adding cloudy filtrate to the auxiliary pulp prior to the filter vat. The auxiliary pulp is preferably supplied to the filter by using directing nozzles or other supply structures, and essentially evenly over the entire radial width of the filter surface.

Abstract: Method of producing a foam-formed fibre or paper web, whereby a foamed fibre dispersion is formed by dispersing natural and/or synthetic fibres in a foamable liquid comprising water and a tenside in a dispersion vessel (111) and by conveying the foamed fibre dispersion to a wire (118) on a paper machine. The foamed liquid which is removed through the wire (118) is conveyed to a closed foam tank (128) in which a draining of the liquid to the bottom of the tank occurs, whilst the lighter foam is collected in the top of the foam tank. Liquid from the bottom of the foam tank is led to the dispersion vessel (111) via a first pipeline (129), whilst foam passes to the dispersion vessel via a second pipeline (130) in the top of the foam tank where the fibres are added and dispersed in the foamable liquid.

Abstract: A wire part of a machine for the production of continuous fibrous material webs, especially a papermaking machine, includes two continuous wire belts which together form a twin-wire zone. At least one supporting element having a supporting surface is disposed in the region of the twin-wire zone. At least a part of the supporting surface provides a supporting region which supports a first wire belt on its inner surface and a second wire belt on its outer surface. At least one formation box is provided and is disposed in the supporting region. The formation box is designed in such a way that, in the region of the inner surface of the second wire belt in the formation box, pressure values can be adjusted from a reduced pressure to an excess pressure acting on the inner surface of the second wire belt. The formation box extends in the direction of movement of the wire part over at least a part of the supporting region.

Abstract: A paper machine forming section with two wire forming units. One of the two forming units is a twin wire web forming unit having a headbox, two wire loops arranged in sandwich-like manner and a drainage element for each of the wire loops. The first web-forming unit has a first section including a curved suction drainage element or roll in the first lower wire loop; a second section with opposing drainage ledges, wherein the drainage ledges are stationary on the upper side and the drainage ledges are developed resiliently pressable on the bottom side; the drainage ledges of the upper and lower sides are arranged staggered with respect to each other in the direction of travel of the wire, and at least the ledges of the upper side are developed with suction; a third section which has at least one suction wire separating element on one side. The second web-forming unit is a hybrid former with a single wire.

Abstract: To regulate the basis weight cross section of the fiber suspension dispensed by the outlet of a headbox of a paper making machine onto the screen or screens of the following forming section, the headbox is sectioned across the width of the machine with individual first sections of fiber suspension across the width. The fiber suspension on the screen(s) in the following forming section is drained and the drained filtrate is collected in second sections respectively generally corresponding to the first sections of the headbox. The removed sectioned filtrate is recycled to the respective sections of the headbox and is mixed with the suspension normally entering the headbox to regulate and make more uniform the basis weight cross section of the fiber suspension.

Abstract: The invention relates to a process and an apparatus for recycling backwater in a papermaking machine. According to the invention backwater draining through a forming fabric is collected into several collecting means (51, 52, 53, 54) and pumped by separate pumps (20) in at least two and preferably numerous separate flows (81 to 85) directly as substantially air free separate flows to the fibre process (12, 30, 40) of the short circulation in order to implement a fast, air free and split recycling of backwater from said forming fabric to said fibre process.

Abstract: White water from a paper machine is treated in an improved fiber recovery process, i.e., the "save-all" process. Prior to the mixing of sweetener stock into the white water the sweetener stock is fractionated (undiluted) into fine and coarse fiber fractions, of which only the coarse fraction is fed as sweetener stock into the white water. The inlet line for the sweetener stock is provided with a fractionation apparatus for removing the fine fraction from the sweetener stock. Treatment apparatus may also be utilized to separate the white water into fine and coarse fractions before passing the fine fraction to a mixer for mixing with the sweetener stock coarse fraction.

Abstract: A papermaking water system utilizing vacuum pump sealing water and having a zero sealing water discharge. A group of water seal vacuum pumps are used in a papermaking machine to generate subatmospheric pressure in suction equipment and thereby extract water from a wet paper web. During operation of the vacuum pumps, the sealing water is heated and the heated water is discharged to a cooling tower to cool the water which is then recirculated to the vacuum pumps. Steam from a generating plant is supplied to the dryer drums in the dryer section of the papermaking machine, and the steam condensate is combined with the heated sealing water flowing to the cooling tower. By using steam condensate as makeup water, no ionic buildup will occur in the closed system, and high quality water is withdrawn from the closed system and may be used in other sections of the papermaking machine, so that there is no discharge of sealing water to the sewer system.

Abstract: White water from a paper machine is treated in an improved fiber recovery process, i.e., the "save-all" process. Prior to the mixing of sweetener stock into the white water the sweetener stock is fractionated (undiluted) into fine and coarse fiber fractions, of which only the coarse fraction is fed as sweetener stock into the white water. The inlet line for the sweetener stock is provided with a fractionation apparatus for removing the fine fraction from the sweetener stock. Treatment apparatus may also be utilized to separate the white water into fine and coarse fractions before passing the fine fraction to a mixer for mixing with the sweetener stock coarse fraction.

Abstract: A method for recycling waste plastic material, from polymeric film or hydropulper waste, including plastic and cellulosic fiber or organic contaminants. The method includes the steps of introducing the waste plastic material into a size reduction unit, and reducing the size of the waste plastic material to particles having a maximum dimension ranging between about 1 inch and about 8 inches; mechanically hammering and rubbing the plastic material for separating a portion of the cellulosic fiber from the plastic; separating another portion of the cellulosic fiber from the plastic by flotation with agitation; further reducing the particle size of the plastic to a maximum dimension of about 1/2 inch; dewatering the plastic; drying the plastic to a moisture content of less than about 10 weight percent; and rolling the plastic into pellets.

Abstract: Method of feeding separate streams of (1) an aqueous dispersion of pulp and (2) white water from a paper making process into a wedge-shaped space between horizontal travelling upper and lower converging wire meshes, applying a siphon means to the upper wire mesh in said zone to form a web of solid fibrous material between the meshes separating the upper wire mesh from the web to leave it supported on the lower wire mesh as the meshes leave the wedge-spaced zone; washing all solids from the wire meshes into a receiving vessel, recycling the contents of the receiving vessel to the paper making process, and recycling the liquid from the white water to the paper making process; and apparatus to perform the above method.

Abstract: Apparatus for pulping a web of broke advancing downwardly thereto comprises an open tub having at least one generally vertical side wall wherein at least one pulping rotor is mounted for rotation on a substantially horizontal axis. A screw of an axial length substantially greater than the maximum axial dimension of each rotor is mounted concentrically on each rotor and extends horizontally therefrom into the interior of the tub to engage a web of broke entering the tub from above and thereby to draw the web into engagement with the associated rotor.