Abstract: A headbox of a paper or board machine having an inlet, a distributor for feeding stock suspension to be distributed over the machine width into the inlet. A turbulence generator downstream of the distributor has a hydraulic diameter of less than 17 mm in the downstream end region. The hydraulic diameter is the diameter of individual channels through the turbulence generator. The turbulence generator has channels or plates that define several channels, each in accordance with the desired hydraulic diameter. Dimensions of the hydraulic diameter are disclosed. The turbulence generator has lands at the downstream end. The land area ratio is disclosed. A nozzle or the like downstream of the turbulence generator introduces the stock suspension over the machine width to a wire or wires of the next section.

Abstract: A dilution control device interconnects a tapered header with a turbulence generator in a paper-making machine. The turbulence generator includes a substantially planar inlet surface and a plurality of fluid passages, with each fluid passage having an inlet at the inlet surface. The tapered header includes a header plate with a plurality of outlets therein, with each outlet being associated with at least one inlet of the turbulence generator. A dilution module block is positioned between and interconnects the header plate with the inlet surface of the turbulence generator. The dilution module block includes a plurality of through holes and a plurality of feed channels. Each through hole interconnects an outlet of the tapered header with at least one inlet of the turbulence generator. Each feed channel is in fluid communication with at least one through hole and is configured for transporting dilution water to a corresponding through hole.

Abstract: Head box for manufacturing a fibrous pulp web. The head box may include a pulp suspension inlet feed device that is sectioned across a width of the head box that feeds a pulp suspension in a feed direction, at least one device having a plurality of entrance ports that produces microturbulences, and an intermediate channel extending across the width of the head box and positioned in front of the at least one device. A plurality of partition units being positionably adjustable into the intermediate channel and being arranged parallel to the feed direction.

Abstract: A three layer headbox for producing a multilayer fiber web. The headbox has top and bottom walls inclined toward each other toward the outlet of the headbox. Top and a bottom separating blades in the headbox, the top blade defining a first chamber toward the top wall, the bottom blade being below defining a second chamber between the blades and also defining a third chamber between the bottom blade and the bottom wall. A respective pulp inlet to each of the three chambers. One of the top and bottom blades being hingedly supported at its upstream end to be adjustable in position for affecting the speed of pulp suspension in respective layers in the chambers affected by the orientation of the blade. The pulp suspension layers passing through a headbox are delivered to a paper machine forming section wire and the three streams from the headbox are combined directly before or upon impingement on the wire.

Abstract: A headbox is provided which provides an improved uniformity in the velocity profile of the stock solution across the slice opening. As a result, improved fiber alignment is provided across the width of the entire slice opening and mis-alignment of the fibers towards the outer edges of the slice opening is avoided. The headbox includes an improved nozzle design with pondsides that are not parallel to one another but which are angled inwardly as they extend from the tube bank to the slice opening. Further, several columns of outer tubes of the tube bank may also be angled inwardly as they extend from the header to the nozzle section. The center tubes would be disposed in a parallel relationship to one another. A sealing arrangement is provided between the roof of the nozzle section and the pondside which permits the incorporation of a double knuckle for extending and retracting the roof to adjust the L/b ratio.

Abstract: An arrangement for feeding stock to a headbox in a papermaking machine which comprises at least one stock header with an inlet for receiving stock into the header and a plurality of stock header outlets permitting stock to leave the header. For each stock header outlet there is a stock conduit downstream of the stock header outlet permitting stock to pass from the stock header outlet, through the conduit to the inlet of the headbox. The arrangement includes a dilution header for feeding a diluent such as water to a plurality of stock conduits. The dilution header has an inlet for receiving a diluent not the dilution header and a plurality of outlets permitting the diluent to leave the dilution header. For each dilution header outlet, there is a diluent conduit permitting the passage of a diluent from the dilution header into a stock conduit.

Abstract: A headbox for suspension having an inlet, an outlet and a suspension guide within the headbox. The headbox provides three layers of suspension. A first transverse suspension supply distributor extending laterally across the headbox for supplying the middle layer of suspension. A second transverse distributor extending across the lateral width of the headbox, of a generally horseshoe shape for partially enclosing the first distributor and the legs of the U of the second distributor providing suspension for the outer two layers of the three layers. The suspension supply to each distributor is either from the same lateral side or from opposite lateral sides of the headbox. Each distributor tapers narrower in cross section from the suspension supply at one side toward the opposite lateral side. The guide in the headbox is at each of the three layers.

Abstract: A headbox employs flow control valves which modulate the flow of stock through each tube of a tube bank, to give greater control over the cross machine direction flow of stock to the forming section of a papermaking machine. In one approach the flow through the tubes making up the tube bank is controlled by rotating cylindrical valve members which extend into portions of the tubes making up the tube bank. The valve members have channels which align with the tubes when the valve is fully opened. Rotation of the control member obstructs the tubes in the column until the desired level of flow from that column of tubes is obtained. In a second approach, pinch valves are created by constructing part of the tube from an elastic material and using air pressure, a cam or a twisting action to reduce the flow through the elastic section thus creating an adjustable valve. A third method employs guillotine valves which selectively block the flow of stock through a column of tubes.

Abstract: A headbox for passing fiber suspension from a headbox entrance to a headbox outlet. A microturbulence insert with a plurality of flow channels inside the headbox. The channels are defined by channel forming elements having upstream ends. The headbox has an antechamber upstream of the turbulence insert. Respective individually adjustable additional feeds for feeding at least one second liquid into the antechamber upstream of the upstream ends of the channel forming elements of the turbulence insert. The feeds are preferably directed counter to the direction of the main flow of suspension into the channels of the turbulence insert. Vanes direct the main flow of suspension through the antechamber to the channels creating a respective sectioned flow to each channel. The additional liquid feeds are positioned to feed their additional liquid into the respective sectional flows after the main flow of suspension has already been diverted to a sectional flow.

Abstract: In the headbox of a papermaking machine;the backplate has a diverging passage for each tube and opens out into the corresponding channel via its largest section; andthe partitions are of length shorter than the length of the chamber between the backplate and the turbulence generator.The invention is useful for paper-making machines in which dilution is controlled upstream.

Abstract: Apparatus for influencing a cross-sectional profile of a headbox having an inner chamber and process for determining a width and position for the sections of the headbox. The apparatus includes a device for distributing fluid that extends across a machine width, at least one connection opening extending across the machine width between the fluid distribution device and the inner chamber of the headbox, and a plurality of elements being one of continuously and discretely adjustably positionable within the fluid distributing device to section the fluid distributing device across the machine width. The process includes measuring a profile of a selected characteristic of the pulp suspension in the headbox that is dependent on its position; forming intersecting points of the profile of the characteristic with a uniform sectioning of the size of the characteristic under consideration; and determining the position and width of the sections.

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 wet end of a paper-making machine, including a headbox with a chamber and a discharge nozzle. A turbulence generator is connected with the headbox and includes a plurality of fluid passages disposed substantially parallel to each other. Each fluid passage is in fluid communication with the headbox chamber and has an inlet. All of the inlets conjunctively define a fluid inlet area. A fiber stock delivery device includes at least one outlet, with all of the outlets conjunctively defining a fluid discharge area. Each outlet is configured to discharge the fiber stock in a direction substantially parallel to the fluid passages in the turbulence generator. The fluid discharge area of the fiber stock delivery device is smaller than the fluid inlet area of the turbulence generator. A hydraulic increaser interconnects the fluid discharge area of the fiber stock delivery device with the fluid inlet area of the turbulence generator.

Abstract: In a foam laid process for producing a non-woven web of fibrous material (such as of synthetic or cellulose fibers) substantially fiber free foam is introduced at various locations in or adjacent to a headbox to get improved results. By introducing pure foam into the foam-fiber mixture near (e.g. just before) where the foam-fiber mixture is introduced into the headbox a more uniform basis weight profile of the non-woven web produced may be provided (e.g. a basis weight variation of about 0.5% or less). By introducing another stream of substantially fiber free foam into the headbox at a surface remote from the foraminous element, to flow along the surface (typically parallel to the flow of the foam fiber mixture), it is possible to minimize shear of fibers in the headbox so that the fibers do not become unidirectional, in the direction of movement of the foraminous element, and keep the surface clean. The surface is typically a roof surface of an inclined headbox.

Abstract: Dosing feeder for the breast box of a papermaking machine. The metering device of this invention serves for the addition or the removal of fluids into or from the breast box of a papermaking machine and includes a chamber for the reception of fluids, with the chamber including a number of metering openings that are connected with the suspension-carrying parts of the breast box via throttling devices, whereby the fluid can be added or removed locally.

Abstract: For distributing stock evenly across the face of a tube bank in a papermaking machine, the stock supply header has an increasing change in cross-sectional area per unit width traveling from the inlet end to the recirculation end of the header. The header top wall converges toward the bottom wall, while the rear wall converges toward the front wall. The change in cross-sectional area down the header from the inlet end to the recirculation end is thus closely matched to an ideally parabolic shape.

Abstract: The present invention provides an apparatus for wet manufacturing a fiber reinforced thermoplastic resin sheet, having a manifold capable of uniformly distributing the solid concentrations without being affected by inertia force caused by the difference in shape between solids. The invention further provides an apparatus for wet manufacturing a fiber reinforced resin sheet having a buffer inlet or reservoir headbox capable of permitting inhibition of variations of the unit weight distribution under the effect of the dynamic pressure of the raw material dispersing liquid and the resultant fluctuations.

Abstract: A headbox has a tube bank of tubes arranged in machine direction rows. The tubes extend from an outlet wall of a header to the inlet of a nozzle. The upper and lower walls of the nozzle converge toward the nozzle outlet, and planes extending from the walls (nozzle roof and apron) converge to define an imaginary centerline extending in the cross-machine direction. The rows of tubes lie along radially extending planes defined with respect to the centerline. The injection ends of the tubes define a cylindrical surface extending between the nozzle walls. Stock from each tube is directed radially toward the centerline along flow paths of equal length. Trailing vanes may be positioned between the rows of tubes so that each flow experiences almost identical flow boundary conditions as it moves towards the nozzle outlet, hence contributing to more uniform fiber orientation in the resultant paper web.

Abstract: Methods and apparatus to enhance paper and board forming qualities with insert tubes and/or a diffuser block in the paper forming machine headbox component which generates vorticity in the machine direction (MD) which is superimposed on the streamwise flow to generate a swirling or helical flow through the tubes of the diffuser block. Tubes of the diffuser block are designed such that the direction of the swirl or fluid rotation of the paper fiber stock may be controlled and the direction thereof is controlled in such a way to provide effective mixing, coalescence and merging of the jets of fluid emanating from the tubes into the converging section, i.e., nozzle chamber of the headbox. Also disclosed is the effective mixing of the jets generating cross-machine direction (CD) shear between the rows of jets that form at the outlet of the tubes inside the nozzle chamber of the headbox to align paper fibers in the cross-machine direction, thus increasing CD strength of the manufactured sheet.

Abstract: An arrangement for feeding stock to a headbox in a papermaking machine which comprises at least one stock header with an inlet for receiving stock into the header and a plurality of stock header outlets permitting stock to leave the header. For each stock header outlet there is a stock conduit downstream of the stock header outlet permitting stock to pass from the stock header outlet, through the conduit to the inlet of the headbox. The arrangement includes a dilution header for feeding a diluent such as water to a plurality of stock conduits. The dilution header has an inlet for receiving a diluent into the dilution header and a plurality of outlets permitting the diluent to leave the dilution header. For each dilution header outlet, there is a diluent conduit permitting the passage of a diluent from the dilution header into a stock conduit.

Abstract: A multi-layer headbox for the production of a multi-layer web of paper has, for instance, three flow planes (I, II, III), each having a pulp feed device (1.1, 1.2, 1.3). In each flow plane a turbulence generator (3) is provided which opens into a nozzle (4). In it there are two plates (5.1, 5.2) which keep two neighboring streams of slurry separate from each other up to the region of the exit slot (8). Each plate is developed as a flexurally soft plate of plastic, the downstream end of which is metal and has a thickness S of at most 0.3 mm. The plastic and metal have a different in coefficients of thermal expansion of <10.sup.-7 1/K.

Abstract: A headbox of a paper machine which is provided with a dilution profiling system which uses a feedback-connected regulation system to control the cross-direction basis weight profile of the paper web produced by the paper machine. The dilution profiling system includes a feed header for a dilution liquid or for a stock suspension of a consistency lower than the consistency in the headbox, feed ducts fill idly coupled to the dilution header and regulation valves associated with the feed ducts for the dilution liquid, whereby the dilution liquid is passed to an area between a front wall of the inlet header of the headbox and a slice duct of the headbox. In the dilution profiling system, edge feed arrangements are integrated in both lateral areas of the headbox.

Abstract: A graphite composite trailing element for a headbox of a paper making machine is described. A protective layer is provided at or around pondside edges of a trailing element. The protective layer reinforces the pondside edges of the element to protect the edges from damage. The protective layer can also provide a protective sheath around the edges of the element to help prevent stock from being absorbed between the composites making up the elements. With reinforced edges and a protective sheath, the bonded composite sheets of the element are less susceptible to separation and delamination thereby resulting in an improved graphite composite trailing element. The protective layer can be made from any number of woven fiber glass mesh materials and is embedded in an epoxy base. The protective layer is compatible with the bonding and curing requirements of the composite sheets making up the trailing element.

Abstract: A method and apparatus for combining a dilution flow with a stock flow passed out of an inlet header in a paper/board machine including dilution flow ducts through which the dilution flow is passed to selected locations across the width of the headbox of the paper/board machine in order to regulate the basis weight of the paper/board web. The dilution flow ducts are constructed so that they becomes narrower toward a final, downstream end. Branch ducts are placed in the area of the narrowing portion of each flow duct, and the dilution flow is passed out of the branch ducts into the system of pipes wherein the dilution flow is combined with the stock flow passed out of the inlet header.

Abstract: A nozzle of a multilayer headbox wherein the headbox includes a nozzle for distributing the stock suspension on a wire. The nozzle is subdivided by at least one machine-wide fin, the fin forming with the nozzle at least two machine-wide nozzle ducts. At least the mean value of the clearance of at least one nozzle duct diminishes steadily in the flow direction, the percentage decrease of the clearance in the fluidically essential area of the nozzle being at least twice as large as in the starting area of the nozzle.

Abstract: Breast box for a papermaking machine. The breast box includes devices in order to add, across the width thereof, localized and dosed material dilution liquids, and located within the breast box is a guiding device having a plurality of channels located immediately downstream of the supply and distribution apparatus, with the guiding device including a multiplicity of inserts in which the channels are located and on whose outer surfaces hollow chambers are formed, wherein the hollow chambers can be filled with the material dilution liquid, the latter then flowing from these hollow chambers into open recesses in the distribution device, with the recesses being directed upstream to the suspension stream existing in the distribution apparatus during the operation thereof.

Abstract: Methods and apparatus to enhance paper and board forming qualities with insert tubes and/or a diffuser block in the paper forming machine headbox component which generates vorticity in the machine direction (MD) which is superimposed on the streamwise flow to generate a swirling or helical flow through the tubes of the diffuser block. Tubes of the diffuser block are designed such that the direction of the swirl or fluid rotation of the paper fiber stock may be controlled and the direction thereof is controlled in such a way to provide effective mixing, coalescence and merging of the jets of fluid emanating from the tubes into the converging section, i.e., nozzle chamber of the headbox. Also disclosed is the effective mixing of the jets generating cross-machine direction (CD) shear between the rows of jets that form at the outlet of the tubes inside the nozzle chamber of the headbox to align paper fibers in the cross-machine direction, thus increasing CD strength of the manufactured sheet.

Abstract: Process for damping pressure pulsations and apparatus for performing the process. The process of this invention serves for the damping of pressure pulsations in a fluid, particularly a fiber suspension, flowing in a closed system wherein the pressure pulsations to be damped are measured at a measuring site and compensated at a correction site, with a throttle position being located between the measuring and the correction sites, with the damping of the imparted pressure impulses occurring at the correction site, which pressure impulses are opposite to the measured pressure pulsations, with the time periods thereof being about the same as those of the measured pressure pulsations. Several apparatuses for performing the process are also set forth.

Abstract: A stock feed system for a multi-layer headbox in which a stock concept is passed into each inlet header in the multi-layer headbox. The stock concepts are produced out of the same fresh stock by adding chemicals and fillers to divided portions of that fresh stock. To this end, the system includes a single fresh-stock container, and stock lines into which the fillers, additives and equivalent are added in compliance with the requirements of each concept. The stock feed system also includes at least one fiber distributor for transferring long fibers out of the stock that is destined to form the surface layer of the paper into the stock that is destined to form a layer placed in the interior of the paper, preferably the middle layer.

Abstract: The invention concerns a headbox of a paper machine wherein an inlet region is provided along the entire width of the machine for introducing the pulp suspension, a discharge region is provided for distributing the pulp suspension along the width of at least one screen, and channels are provided between the inlet region and discharge region in which turbulence is produced in the pulp suspension (turbulence region). According to the invention, the turbulence region is formed with the aid of a number of channels, the cross-section of which, perpendicularly to the plane of flow, has an elongated form and may be variable.

Abstract: A headbox for a papermaking machine with an outlet slot that distributes pulp suspension over the, working width of the papermaking machine. For controlling operating parameters of throughput, pulp density and fiber quality of the suspension over the width of the machine, the headbox has a plurality of individual sections across the width of the machine. Each section has respective channels therethrough for passing pulp suspension. At least one connection at each section is to a controllable supply of pulp suspension where the operating parameters of that supply are controllable. Only separate operating parameter controlled streams pass through the sections of the headbox. Operating parameter control devices may deliver adjusted streams to a mixer upstream of the headbox channels. The mixer may also have individual sections across the width of the machine.

Abstract: Process for modifying an existing breast box for a paper or cartonmaking machine as well as an intermediate portion for carrying out the process. During the fabrication of a breast box for a paper or cartonmaking machine an intermediate portion is interposed between a supply apparatus and a downstream guiding device, with the material suspension flowing through this intermediate portion wherein, via supply lines, located on the intermediate portion, a liquid is added which differs from that of the suspension stream. Particularly, in this manner, already existing breast boxes can be converted, to water dilution technology, with this invention setting forth special embodiments of differing intermediate portions that can be utilized therefor.

Abstract: The present invention involves a headbox and manifold system for producing a multi-ply paper which includes a plurality of mixing systems for generation of stock suspension flows of differing concentrations and a distribution manifold for providing a different stock suspension for each of the plies. For at least one of the plies, two conduits or manifolds are used to carry stock suspensions of differing concentrations thereby permitting the adjustment of the concentration of the stock suspension used to form that ply. Each manifold is fixed to the support structure of the paper making machine and runs transverse to the machine direction. Each of the manifolds is in fluid communication with the movable headbox by means of flexible lines of equal length. After discharge from the flexible lines the stock suspensions are routed through turbulence generators before being discharged from the headbox through a slice nozzle to form a multi-ply paper web.

Abstract: A method and device in the regulation of a headbox. The headbox includes a pulp inlet header, after the pulp inlet header, seen in the pulp flow direction, a distributor manifold whose pipes are opened into an intermediate chamber. The headbox comprises an attenuation chamber placed in connection with the intermediate chamber and, after the intermediate chamber, a turbulence generator having tubes which are opened, at their outlet end, into a discharge duct and, at their inlet end, into the intermediate chamber. In the method, into different positions along the width of the headbox, a pulp suspension flow is introduced, the concentration of this flow is adjustable by combining two component flows. In the method, in the regulation of the concentration of the flow passed into the pulp suspension, two component flows are combined by into the pulp suspension flow introducing an additional flow. The mixing ratio of the combined flow is regulated by adjusting the additional component flow.

Abstract: A device for the sectional supply of pulp suspension to a headbox of a papermaking machine includes a plurality of main inlet lines from a pulp suspension distributor which are distributed over the width of the machine. A throttle is provided in at least one main inlet line. Downstream of the throttle, in at least one of the main lines, a subsidiary line for conveying a subsidiary stream of liquid, such as a pulp suspension or water, is connected to the main inlet line and disposed at an angle to the main inlet line. This angle between the main pulp stream and the subsidiary stream is chosen so that a small change in the rate of flow of the subsidiary stream will cause a large change in the rate of flow of the total stream (main pulp stream+subsidiary stream) directed in the same direction or in the opposite direction of the stream.

Abstract: A method and device in the regulation of the headbox of a paper machine/board machine, in which additional flows are introduced into the pulp suspension at different points across the width of the headbox. The concentration of the additional flows is different than the average concentration of the pulp suspension. The additional flows are introduced through additional-flow pipes to the vicinity of inlet openings of turbulence tubes of a turbulence generator. The grammage profile of the web in the direction of width of the web is regulated in the headbox by adjusting the distance of the end of the additional-flow pipe/pipes from the turbulence generator, whereby the amount of the additional flow entering into the additional-flow pipes and, at the same time, the amount of the pulp suspension flow are regulated.

Abstract: A multilayer headbox for the introduction of at least two fiber suspension streams to the forming section of a paper manufacturing machine includes a nozzle chamber further defined by two stream guide walls which end at an outlet gap and by two side walls. At least one lamella is provided in the nozzle chamber, this lamella keeping at least two fiber suspension streams separated from each other through the region of the outlet gap. The lamella includes a body, preferably made of plastic, and a tip made of a hard material. The tip is either a strip or a coating having a sharp tip-edge integrated into the body of the lamella.

Abstract: A method and apparatus for reducing turbulence in a pulp flow stream flowing through a paper making machine headbox includes providing lamellae disposed in a portion of the headbox. A lamella end portion is modified which provides for the flushing of a dead space formed in the wake of the lamella. The modified lamella end portion produces small flow channels which divide the pulp stream flowing past the lamella into a plurality of substreams and guides the substreams into the region of the dead space.

Abstract: Breast box for a papermaking machine. A breast box for a papermaking machine includes at least one distribution device for a material suspension extending over the width of the papermaking machine, at least one adjacent intermediate chamber located downstream of the distribution device, at least one guiding device for the suspension located adjacently downstream of the intermediate chamber, a nozzle chamber, having a wide aperture, located adjacently downstream of the guiding device, with the guiding device, the intermediate chamber and the distribution device being releasably connected with each other, and the intermediate chamber and the distribution device being pivotally journalled about a common fixed pivot axis, with the common pivot axis extending horizontally and laterally to the longitudinal direction of the papermaking machine, with the common pivot axis also extending through at least one pillow block fixedly connected with the seat or the foundation of the papermaking machine.

Abstract: A headbox of a paper/board machine including a set of valves, each of which is arranged to distribute a flow to a different point in the direction of width of the headbox. Each valve is capable of regulating both the flow quantity of the flow departing from the valve and the consistency of the flow departing from the valve. Further, each valve includes an input line for the stock flow and an input line for a diluting flow, which is preferably a diluting-water line, and the flows are combined in the valve. The combined flow is passed into the headbox into connection with the stock flow present in the headbox coming from a stock inlet header to be mixed therewith. The headbox includes a turbulence generator arranged after and connected to the stock inlet header in the flow direction. The turbulence generator includes turbulence tubes which open into a slice duct, preferably a slice cone, from which the stock is passed onto a forming wire.

Abstract: The invention concerns a method of controlling the relative flow speed of the layers in a multi-layer headbox with laminae mounted torque-free between upper and lower lips which are stationary when in operation. The invention is characterized in that a difference in speed is produced between the individual layers by causing the static pressure to change differently in the different layers.

Abstract: A multilayer headbox of a paper machine for producing a paper web with several layers having different properties, and an appropriate method therefor. In at least one first layer there is adjusted alone the fiber orientation cross profile and in at least one second layer there is adjusted alone the basis weight cross profile.

Abstract: A headbox of a machine for producing a fiber web from a pulp suspension which travels in a flow direction through the headbox has a first chamber into which a pulp suspension is introduced, a second chamber provided downstream of the first chamber, and at least two walls provided in a region between the first and second chambers so that the pulp suspension flows between the two walls. Each of the two walls has a non-planar, contoured surface to generate turbulence in the pulp suspension flowing between the two walls. The headbox also includes means for longitudinally shifting at least one of the two walls with respect to the other wall to control the turbulence generated in the pulp suspension.

Abstract: A nozzle of a multilayer headbox wherein the headbox includes a nozzle for distributing the stock suspension on a wire. The nozzle is subdivided by at least one machine-wide fin, the fin forming with the nozzle at least two machine-wide nozzle ducts. At least the mean value of the clearance of at least one nozzle duct diminishes steadily in the flow direction, the percentage decrease of the clearance in the fluidically essential area of the nozzle being at least twice as large as in the starting area of the nozzle. The fin has downstream end area of decreasing thickness immediately preceded by an area of increasing thickness.

Abstract: A multi-layer headbox including at least two inlet headers for stock through which separate stocks are passed into a system of distributor pipes and further through a turbulence generator into a slice cone narrowing in the stock flow direction. Flaps are placed in the slice cone and one end of the flaps is attached to the turbulence generator. The flaps have at least two flap faces between which a step is formed. The step is arranged on the flap in an area in which the flap, and the flow duct, is curved and its the function is to dissipate any secondary vortices that might form on the curved flap face.

Abstract: A headbox for a paper machine is characterized by having: at least one machine-wide channel region which defines a main direction of flow; a region for the production of turbulence; a plurality of feed lines distributed over the machine width and discharging into the headbox channel region; an adjusting device in each feed line for controlling the quantity of flow; an angle .alpha. between the main direction of flow and the feed line; and the angle .alpha. being selected in such a manner that, regardless of the amount fed by the feed line, the total volumetric flow in the region directly downstream of the feed line remaining constant.

Abstract: A method and device in the regulation of a headbox. The headbox includes a pulp inlet header, after the pulp inlet header, seen in the pulp flow direction, a distributor manifold whose pipes are opened into an intermediate chamber. The headbox comprises an attenuation chamber placed in connection with the intermediate chamber and, after the intermediate chamber, a turbulence generator having tubes which are opened, at their outlet end, into a discharge duct and, at their inlet end, into the intermediate chamber. In the method, into different positions along the width of the headbox, a pulp suspension flow is introduced, the concentration of this flow is adjustable by combining two component flows. In the method, in the regulation of the concentration of the flow passed into the pulp suspension, two component flows are combined by into the pulp suspension flow introducing an additional flow. The mixing ratio of the combined flow is regulated by adjusting the additional component flow.

Abstract: A three-layer headbox has two rigid separator vanes (11; 12) mounted in the headbox slice chamber (10) to form two outer stock flow channels (39; 41) and an intermediary one (40). The upstream end of each vane (11; 12) is securely fixed in cantilever fashion and its downstream end (15; 16) is unattached and free and provided with a vane extension (17; 18). Also the downstream end (20; 22) of the extension (17; 18) is unattached and free and is located just downstream of the slice opening (14). The vane extension (17; 18) is thinner than the vane (11; 12), so that a step (23, 24) is formed on each side of the vane (11; 12) and extension (17; 18) assembly. To improve the layer formation, each vane (11; 12) and each vane extension (17; 18) has a portion located in a converging downstream portion (13) of the slice chamber (10), and the vane portions and the extension portions are of substantially equal length.

Abstract: This invention relates to headboxes which are used in papermaking machines. The inventive structure employs the use of a plurality of venturis located between the headbox chamber and the slice. Each venturi is located adjacent to a pulp conduit spaced transversely across the headbox chamber.

Abstract: A turbulence insert of a headbox of a papermaking machine is provided that includes a bundle of channels for guiding the suspension of materials from a first region to a second region. The channel bundle is comprised inpart of edge channels that have no adjacent channel on at least one longitudinal side, and is also comprised in part of central channels that have at least one adjacent channel on each longitudinal side. Also, at least two adjacent edge channels are provided that are joined with each other at least one part of their length.