Abstract: An apparatus for processing a continuous web having a first side and a second side includes a plurality of rollers are arranged for cooperative rotation. The plurality of rollers are positioned to define a corresponding plurality of nips. The continuous web is processed through at least two of the plurality of nips. At least a first roller of the plurality of rollers has at least one void formed in the cylindrical middle surface. First and second sealing panels engage first and second circular ends of each of the plurality of rollers and define a chamber. A first pressure source is fluidly coupled to the chamber to pressurize the chamber. A membrane is positioned adjacent the first side of the continuous web to separate the continuous web from direct communication with the chamber.

Abstract: The invention relates to a roll for a paper or board machine comprising axle journals on whose support the roll is arranged to revolve, end flanges with which the axle journals are connected, and a mantle which is connected with the end flanges. The mantle is provided with a number of openings extending through the mantle and/or recesses formed into the outer surface of the mantle, which openings and/or recesses form a regular pattern. Solid connecting portions in the outer surface of the mantle around said openings and/or recesses are opened to that, from each opening and/or recess, there is a connection, provided in the form of a groove or an additional recess extending into the outer surface of the mantle, with at least each of the openings and/or recesses adjacent to it.

Abstract: Suction box in a paper machine including a vacuum chamber, a deck or a number of substantially U-section holders open toward a wire and ribs arranged in the deck or the holders so that they can be loaded against the wire. At least in a running situation, the deck of the suction box is curved or the ribs are arranged to provide a curve run of the wire so that the wire tension of the curved run over the deck or ribs serves to lower a normal force which is produced by the vacuum present in the suction box and which is effective between the wire and the deck or ribs.

Abstract: Pressing section of paper machine including first and a second pressing stations, a common lower felt arranged to run through first and the second pressing stations, and an first upper felt and a second upper felt arranged to run through first and second pressing stations. Second pressing station includes shoe press roll located above a lower roll, and pressing plane of second pressing station is oriented essentially vertically or inclined at an angle &bgr;, which is a maximum of about 20° to vertical. The common lower felt is sufficiently dense to be essentially air impermeable even in its new state after moistening, and is sufficiently open to allow water through at pressures greater than about 5 bar. First and second upper felts are sufficiently open to allow air through in their moistened, uncompressed state, and pressing plane of first pressing station is oriented at an angle greater than angle &bgr;.

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 suction box comprises a fixed frame part (11) and a lid part (12) disposed in the frame part (11) to be movable. The moving lid part (12) moves relative to the fixed frame part (11) with the aid of gravity or with the aid of expansion members (15a, 15b, 15c) positioned in link points between said two parts (11, 12). On the moving lid part (12), sealings (13a, 13b, 13c) are fitted, wherewith the suction box is sealed against the inner face of a shell (14) of a suction roll. In the link points between the fixed frame part (11) and the moving lid part (12), locking means (20) are disposed, wherewith the moving lid part (12) can be locked relative to the fixed frame part (11) in a desired position.

Abstract: A system and method effectively threading the moist tail of a web through a pulp dryer. A tail threading belt in a closed loop passes the tail of the web through the dryer, and the most tail of the web is transferred from a support wire in the press section of a pulp machine to the tail threading belt. Transfer may be effected using a suction roll with a suction sector and a blower sector, or by using a suction chamber having a perforated escort belt which cooperates with it to engage the tail section on the wire and fully support it during transfer to the threading belt. The threading belt may be folded over to contain the tail web inside it while it passes through the dryer.

Abstract: In manufacturing a moving web, such as a tissue sheet, the web is transported at very high speeds, often in an unsupported manner, which can result in unstable operations regarding handling and winding of the web. This is particularly true in the region between the creeping blade and the reel for a lightweight, low modulus tissue sheet that is characteristic of a high-quality, soft tissue base sheet. To provide an improved means of controlling the tissue web during manufacture and to improve the manufacturing rate, an apparatus and method of stabilizing the moving web that incorporates a creeping blade foil, one or more aerodynamic sheet stabilizing foils, and a roll foil in a specific relationship to each other is disclosed. This method has been shown to improve the stability of a moving tissue web, allow for a higher rate of operation, and enable the production of softer tissue basesheets.

Abstract: A suction box in a paper machine including a vacuum chamber, a deck or a number of substantially U-section holders open toward a wire and ribs arranged in the deck or the holders so that they can be loaded against the wire. At least in a running situation, the deck of the suction box is curved or the ribs are arranged to provide a curve run of the wire so that the wire tension of the curved run over the deck or ribs serves to lower a normal force which is produced by the vacuum present in the suction box and which is effective between the wire and the deck or ribs. A method in a suction box in a paper machine, wherein a vacuum is formed in a vacuum chamber of the suction box and, during formation of the vacuum, the deck and/or the ribs is/are pressed against the wire.

Abstract: A method and arrangement for preventing rewetting of a web in a paper machine. In the method, a web supported by a wire is passed by at least two vacuum boxes/chambers after the last suction roll or equivalent in a web former such that, in the running direction of the web, by means of a first vacuum box/chamber and by means of a second vacuum box/chamber the transport of moisture from the wire back into the web is prevented. In the arrangement at least two vacuum boxes/chambers are arranged after the last suction roll or equivalent in a web former, and the web and wire are arranged to be dewatered by means of a first vacuum box/chamber and the transport of moisture from wire back into the web is prevented by means of a second vacuum box/chamber, the vacuum generated in first vacuum box/chamber being higher than the vacuum generated in the second vacuum box/chamber.

Abstract: Suction box in a paper machine including a vacuum chamber, a deck or a number of substantially U-section holders open toward a wire and ribs arranged in the deck or the holders so that they can be loaded against the wire. At least in a running situation, the deck of the suction box is curved or the ribs are arranged to provide a curve run of the wire so that the wire tension of the curved run over the deck or ribs serves to lower a normal force which is produced by the vacuum present in the suction box and which is effective between the wire and the deck or ribs.

Abstract: A device for conveying and guiding a lead-in strip in a paper machine which includes a conveyor formed of an air permeable material, the conveyor having a run with opposed faces on respective sides. The lead-in strip is conveyed on a first face on a first side of the run. The device also includes a foil rib located on a second side of the run of the conveyor. The foil rib includes a foil head for producing a vacuum effect on an outlet side of the foil head in the direction of movement of the run.

Abstract: A paper machine for manufacturing a structured soft paper web are described, which machine has a wet section, a press section, a drying section and a web-carrying clothing running around a suction device close to a smooth impermeable belt in the press section for the creation of a transfer point. In accordance with the invention, structuring means for structuring the web are arranged between the press section and the drying section.

Abstract: An apparatus and process for transporting at least a portion of a web of flexible material between first and second structures spaced from each other. The apparatus includes at least two pulleys located at spaced locations from each other, and an air-pervious endless belt movably mounted on the first and second pulleys. The belt has a run traveling from the first pulley, adjacent the first structure, to the second pulley, adjacent the second structure, and the belt is adapted and arranged to receive the at least a portion of the web from the first structure. An underpressure source is arranged to produce an underpressure adjacent to the run of the endless belt. A nose shoe is disposed beyond the second pulley and spaced from the second pulley, so as to define an opening between the nose shoe and the second pulley at a second position where the at least a portion of the web leaves the endless belt.

Abstract: A machine for producing a tissue web is provided, including a former having a forming region which includes at least one circulating, continuous dewatering wire having zonally variable wire permeability. Furthermore, a process for producing the tissue web in a tissue machine is provided. The process includes forming the tissue web in a forming region of a former, wherein the forming region includes at least one circulating, continuous dewatering wire having zonally variable wire permeability.

Abstract: A sealing construction for loading a seal against a suction roll in a paper machine includes a seal having a wear surface, side surfaces and a lower surface. The seal is fitted from its holder to the structure of a suction box which is inside the suction roll. The seal essentially covers the whole operating length of the suction roll, extending from its wear surface to the inner face of the mantle of the suction roll. The seal is moveable in the direction of the radius of the suction roll in the holder by a pressure effect that is applied directly onto the lower surface of the seal. Negative pressure or vacuum can be applied during operation to draw the seal into its holder to reduce seal wear.

Abstract: A web of tissue is formed in a crescent former, followed by an air press for water removal in the pressing section, passing onto a Yankee dryer. A headbox injects stock between upper and lower dryer fabrics brought together on a breast roll. The fabrics move over vacuum boxes, and the web is heated with steam and passed between an upper pressure box and a lower vacuum box forming an air press which dewaters the web. A sheet transfer pickup vacuum box holds the sheet to the upper fabric as the lower fabric diverges from the upper fabric. A pressure roller transfers the web onto a Yankee dryer. The fabrics are cleaned on vertical runs before returning to the breast roll. A second upper fabric or transfer fabric operating at a lower speed then the first can be used to form a rush transfer between the forming fabrics and the Yankee dryer which increases web bulk and absorbency. Instead of a second fabric, a vacuum pressure roll may perform the rush transfer between the lower forming fabric and the Yankee dryer.

Abstract: An apparatus for penetrating a sheet material web being carried on a fabric. The apparatus including a penetrating device and an air flow that separates a portion of the sheet material web from the fabric adjacent the penetrating device so as to bring the web into contact with the penetrating device. In one embodiment, a vacuum lifts a portion of the sheet material web into contact with a slitting member such that it continuously slits the sheet material web longitudinally along its length as the fabric carries the sheet material web beneath it. In an alternative embodiment, a pressurized air stream is directed to a bottom portion of the sheet material web so as to separate the web from the fabric.

Abstract: Suction device and process for at least one of conditioning and drainage of an endless felt. The device includes a housing having at least one vacuum chamber, and a plurality of suction slits located on a suction surface of the housing that is adapted to face the endless felt. The plurality of suction slits are oriented to extend at least one of in and obliquely to a travel direction of the endless felt. The process includes guiding the endless belt over a suction surface of a vacuum chamber, and suctioning a surface of the endless belt with a plurality of suction slits located in the suction surface of the vacuum chamber. The plurality of suction slits extend in a direction that is at least one of in and oblique to a belt travel direction.

Abstract: A method in a paper machine for transferring a paper web from a wet wire in a former section to a pick-up fabric or an equivalent transfer fabric of a press section, including the steps of forming a pick-up point on the wet wire and separating an edge strip from at least one edge of the web prior to the pick-up point by means of at least one cutting device. The method further includes separating the web from the wet wire and passing the web onto the pick-up fabric at the pick-up point. The method also includes applying a pressure difference to the at least one edge strip through the wet wire or the pick-up fabric at or after the pick-up point to cause the at least one edge strip to either follow the wet wire or become separated from the pick-up fabric after the pick-up point and to be placed in a broke system arranged beneath the paper machine.

Abstract: In the present invention, in a process in which a fiber suspension supplied in a flat layer manner is subjected to natural dehydration, pressure dehydration, or suction dehydration, while circulating a cylindrical suction cylinder, and thereby, dehydration slowly proceeds and a paper web is formed, and this paper web is moved to an endless felt by means of a suction couch roll to produce paper, a tapered suction roll sleeve 6, the outer peripheral surface of which is cylindrical and the inner peripheral surface of which has an inclination identical to that of the outer circumference of the tapered suction roll cell 5 is attached and detached, and thereby, it becomes easy to conduct the attachment and detachment of various types of wires wound on tapered suction roll sleeve 6.

Abstract: Suction roll for the formation or treatment of a material web that includes an outer suction roll jacket comprising a perforated rotating hollow cylinder, a non-perforated support body arranged to extend through the outer suction roll jacket and to support the outer suction roll jacket at at least one point of its axial extent, and sealing ribs arranged to extend radially between the support body and the suction roll jacket and axially over a full length of the suction roll jacket. In this manner, the support body is adapted to rotate at a same speed as the suction roll jacket. The support body can include an axially extending, through-going bore arranged concentrically with the outer suction roll surface. An axially extending, rotationally fixed yoke extends through the through-going bore, and the rotationally fixed yoke has two ends which are supported outside of the support body on a frame. At least one support element is arranged to support the support body on the yoke.

Abstract: The invention refers to a process for dewatering a pulp web, particularly a chemical pulp web, where dewatering takes place between twin wire belts or felts in an initial dewatering zone with a set area pressure and then in a second dewatering zone. It is mainly characterized by the area pressure in the initial dewatering zone being pre-set, and in the second dewatering zone it is adjustable, with the web being dewatered in both directions (upwards and downwards). The invention also refers to a device for implementing the process.

Abstract: The invention relates to a method for preventing rewetting of a web in a former. Water is removed from the web (W) by means of dewatering members. The web (W) is formed by forming members and forming rolls on support of a wire loop/loops. The wire loop/loops (10) is/are guided by alignment, guide and/or suction rolls (11, 12). The web (W) supported by a wire (10) is passed by at least two vacuum boxes/chambers (16, 17) after the last suction roll (11). At least two vacuum boxes/chambers (16, 17) are fitted after the last suction roll (11). The web (W) and the wire (10) are arranged to be dewatered by means of a first vacuum box/chamber (16). The transport of moisture from the wire (10) back into the web (W) is prevented by means of a second vacuum box/chamber (17), and a vacuum (P.sub.1) in the first vacuum box/chamber (16) is higher than a vacuum (P.sub.2) in the second vacuum box/chamber (17).

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: Suction device for use in a machine for producing a sheet and a method to vacuum a web section of a paper machine. The suction device includes a contact surface to place on the web section and a suction box. The suction box is designed to have a vacuum pressure applied to drain the web section. The suction device further includes a control device and a release mechanism or an adjustment mechanism for releasing the suction box from the web section while the vacuum pressure is applied or thereafter so that the web section is guided along the contact surface with less friction and without the web section detaching from the contact device. A method to suction a web section in a paper machine including arranging a contact surface a suction device on the web section and applying a vacuum pressure to the suction device to vacuum the web section.

Abstract: Paper fiber suspended in black liquor is washed in a rotating drum divided into a plurality of adjacent sectors. The fiber is formed into a mat on the drum, and the drum is rotated so the sectors progress through a first wash and a second wash of progressively cleaner wash fluid. Each sector has two distinct drainage systems. One drainage system drains the first wash water after it has passed through the mat, and is then blocked while that sector passes through the second wash. The cleaner second wash fluid is thus kept separate from the more contaminated first wash fluid, and is recirculated to be used in subsequent cycles as first wash fluid.

Abstract: A water jet edge trimming station for trimming the edges of coated paper during on-machine operation includes backsplash compensating features. The edge trimming station has a cutting station over which the web travels to be cut. The water jet travels along a water jet axis to a point of impingement at the cutting station to cut the web. The cutting station has an effluent receiving aperture at the point of impingement. A negative pressure mixing zone located below the aperture draws effluent by-products or backsplash associated with cutting of the web below the cutting surface of the web. The water jet axis is offset a first predetermined angle chosen relative to a normal axis passing at right angles through the point of impingement to reduce backsplash. The water axis jet is rotated about the normal axis by a second predetermined angle to direct the effluent by-products away from the water jet nozzle and the traveling web.

Abstract: A machine for manufacturing a continuous material web, in particular a paper or cardboard web, with at least one perforated cylinder sleeve and a suction roll exhibiting a manhole around which the material web is guided preferably with the aid of a transport band, whereby the interior of the suction roll can be put under a vacuum and is subdivided into at least two sections by a partition wall that is arranged essentially perpendicular to the rotation axis of the suction roll, wherein the partition wall is subdivided into sections and/or is manufactured of a flexible material and can thereby be inserted through the manhole and into the roll interior.

Abstract: A web support foil positioned adjacent to a Yankee dryer above a creping doctor. The foil supports the web as it leaves the dryer. Mounted to the top of the foil is an adjustable air deflector which is positioned tangent to the Yankee dryer. The air deflector blocks air moving along the web. A slotted opening draws air from a leading-edge pocket collecting fibers which are broken loose during the creping action. The web is held against the bottom side of the foil by one or more air jets which are directed over the bottom surface on the foil. The jets of air function as coanda air jets and prevent the web from sticking to the bottom surface of the foil while creating a Bernoulli effect which holds the web against the bottom of the foil.

Abstract: Uncreped throughdried cellulosic webs having improved smoothness and stretch are produced by transferring a newly formed web from the forming fabric to a slower moving, high fiber support transfer fabric, preferably using a fixed gap or kiss transfer in which the forming fabric and the transfer fabric converge and diverge at the leading edge of the transfer shoe. The web is then transferred to a throughdrying fabric and throughdried to final dryness, producing a web having an improved softness due to increased surface smoothness.

Abstract: A papermaking vacuum apparatus having a web-facing surface adapted to support a papermaking belt and comprising a head, a body and at least one vacuum slot disposed in the head and defining an aperture on the web-facing surface. The vacuum slot is in fluid communication with the web-facing surface and extends from the web-facing surface to the body which is in further fluid communication with a vacuum source. The web-facing surface has a textured clothing interposed between the web-facing surface of the vacuum apparatus and a backside of the papermaking belt. The textured clothing creates leakage between the backside of the papermaking belt and the web-facing surface of the vacuum apparatus and effectively eliminates the vacuum seal between these two surfaces.

Abstract: A method for improving the rush transfer of a web, such as a tissue web, is disclosed. The method provides for greater angles of convergence and divergence of the carrier fabric and the transfer fabric at the point of transfer by deflecting the carrier fabric toward the transfer fabric using a deflection element, such as a roll, positioned opposite the vacuum transfer head. The greater angles of convergence and divergence minimize the potential for undesirable macrofolds being formed in the web during transfer.

Abstract: A papermaking vacuum apparatus having a web-facing surface adapted to support a papermaking belt and comprising a head, a body and at least one vacuum slot disposed in the head and defining an aperture on the web-facing surface. The vacuum slot is in fluid communication with the web-facing surface and extends from the web-facing surface to the body which is in further fluid communication with a vacuum source. The web-facing surface comprises a textured area in the region of the web-facing surface juxtaposed with the aperture defined by the vacuum slot. This textured area creates a leakage of at least about 35 Marlatts at a pressure differential of 7 inches of Mercury. This leakage eliminates the vacuum seal between a smooth backside of the papermaking belt and the web-facing surface of the vacuum apparatus.

Abstract: A papermaking vacuum apparatus having a web-facing surface adapted to support a papermaking belt and comprising a head, a body and at least one vacuum slot disposed in the head and defining an aperture on the web-facing surface. The vacuum slot is in fluid communication with the web-facing surface and extends from the web-facing surface to the body which is in further fluid communication with a vacuum source. The vacuum apparatus has a flow management device facing said web-contacting surface of the papermaking belt and disposed such that the papermaking belt having the paper web thereupon travels between the flow management device and the web-facing surface of the head. The flow management device has an air flow resistance and controls the distribution of the air flow through the aperture on the web-facing surface such as to effectively increase in the machine direction the amount of vacuum pressure applied through the vacuum slot to the papermaking belt.

Abstract: A method for removing air from a suction roll/suction cylinder and a suction roll/suction cylinder including a roll mantle, end flanges connected to the roll mantle and axle journals for revolvingly supported the roll mantle. The mantle has numerous perforations, holes or equivalent openings passing therethrough. The suction roll/suction cylinder is connected to a suction duct that passes onto the interior of the roll/cylinder and transfers a vacuum force therein. Air is drawn or sucked through the perforations into the interior of the roll mantle so as to press a paper web toward an outer face of the roll mantle. The suction roll/suction cylinder has a system of suction pipes connected with the suction duct and including at least one suction pipe into which air is guided and/or sucked from the vicinity of the inner face of the roll mantle of the roll/cylinder.

Abstract: A method of applying a film of coating material to a web of pulp product on a machine and an apparatus for carrying out the method. The coating material is directed in a fluid against the surface of a web of pulp product in the form of a high volume low velocity atomized spray mist from high volume low pressure spray nozzles with an exiting air pressure from the spray nozzle of 1 to 10 psig, preferably 3 to 6 psig.

Abstract: A method and apparatus for transferring a web from a forming fabric in a forming section of a paper making machine to a transfer felt or fabric is disclosed including directing the web carrying forming fabric in a substantially longitudinal direction adjacent an underside of a transfer shoe in a transfer zone the said web being positioned between the forming fabric and the transfer shoe and the transfer shoe having a substantially planer lead-in surface and an arcuate exiting surface of a predetermined radius, the lead-in surface including an arcuate trailing edge having a predetermined radius less than that of the arcuate exiting surface with the trailing edge and the exiting surface being separated by a suction opening, directing the transfer felt in a substantially longitudinal direction adjacent the underside of the transfer shoe with the transfer felt being positioned between the web and the transfer shoe, the transfer felt entering the transfer zone at an angle with respect to the forming wire, creating

Abstract: A method for causing adherence of a web to a drying wire so as to prevent the effects of centrifugal forces and of other air-flow phenomena, which effects attempt to separate the web from the drying wire in dryer groups having a single-wire draw and arranged in a multi-cylinder dryer of a paper machine. The dryer groups include heated drying cylinders, a drying wire for pressing the web against outer cylinder faces of the drying cylinders, and guide cylinders or rolls on which the web runs on the outside face of the drying wire. The guide cylinders have perforations which pass through the cylinder mantle and open into an inside space in the interior of the guide cylinders which is subjected to a vacuum. The vacuum in the guide cylinders is transferred to the outside face through the perforations. The guide cylinders have shafts on which the guide cylinders are mounted revolving.

Abstract: The invention is directed to a press system of a paper machine for making tissue, including a crepe drying cylinder, a press roll with a smooth surface, an extended-shoe press unit, and a press roll fashioned as a suction roll or grooved roll. A first press gap is formed by the press roll with a smooth surface and the press roll designed as a suction roll or grooved roll. A water collection tub is coordinated with the suction roll or grooved roll. A second gap is formed between the press roll with the smooth surface and the extended-shoe press unit after which the felt leaves the periphery of the press roll with the smooth surface. Following thereafter, a third press gap is provided between the press roll with the smooth surface and the crepe drying cylinder. The felt does not pass through the third press gap.

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: Improved system for controlling the forming and dewatering of a web of paper by submerged drainage in which air does not penetrate the fiber/aqueous dispersion and the formed web. The dewatering is via altering the natural tension of the meniscus of the water to induce enhanced drainage of water from the aqueous dispersion of paper making fibers in the wetter end of the system and from the drier end of the fabric. Also, the improved horizontal system provides substantially equivalent side surfaces to the paper formed in such system.

Abstract: Improved apparatus for controlling the dewatering of a web (44, 44') in a Fourdrinier fabric (20, 21) by submerged drainage apparatus in which air does not penetrate through the fiber/aqueous dispersion nor the formed web (44, 44'). The dewatering is accomplished by altering the natural tension of the meniscus of the water to induce enhanced drainage of water from the aqueous dispersion of paper making fibers in the fabric (20, 21) and replacement air for the water draining from the formed web (44, 44') is provided from beneath the lower fabric (20) and, if an upper fabric (21) is employed, from above the upper fabric (21).

Abstract: A suction pipe assembly for dewatering a web in a papermaking machine includes a rotating pipe supporting suction cover and attached to a frame by a bearing sleeve. Support members extend form the bearing sleeve to the pipe without obstructing the flow of air through the pipe.

Abstract: A curved suction box apparatus is disclosed for guiding a web towards a nip of a nip press. The apparatus includes an initial shoe which is disposed upstream relative to the nip, the shoe defining a convex surface for guiding the web. A box is disposed downstream relative to the initial shoe for guiding the web from the initial shoe. The box is connected to a partial vacuum.

Abstract: A dryer section for a machine for drying a fibrous web and particularly a paper web. The dryer section comprises a row of dryer cylinders which alternate with reversal suction rolls along the path of the web. The dryer cylinders are separated into at least an upstream first dryer part and a downstream second dryer part in the path of the web through the dryer section. A continuous supporting belt travels along with the web alternately over each dryer cylinder and its associated suction roll in respective dryer groups in each of the upstream and downstream dryer parts. Every suction roll in the upstream first part has a stationary suction box in it. Every suction roll in the downstream second part does not have a suction box. All of the suction rolls have a perforated roll shell. The density of the perforations in the roll shell of the suction rolls in the first upstream part is at least twice as great as the density of the perforations in the roll shell of the suction rolls in the second downstream part.

Abstract: A saveall apparatus is disclosed for collecting water ejected from stock through a forming wire of a papermaking machine. The apparatus includes a box which is disposed closely adjacent to the forming wire. The box defines an enclosure which is connected to a source of partial vacuum so that water ejected from the stock is collected within the enclosure. A throat wall is rigidly secured to the box and has an upstream and a downstream end. The upstream end of the throat wall slidingly engages the forming wire. A moveable throat wall cooperates with the throat wall for defining therebetween a vacuum slot which is connected to the enclosure such that the water ejected from the stock is drawn by the partial vacuum through the vacuum slot into the enclosure. The throat wall is disposed in a first plane, and the moveable throat wall is disposed in a second plane such that when the moveable throat wall is moved relative to the throat wall, an angle defined between the planes remains constant.

Abstract: A gap former in a paper machine, comprising a lower wire loop (10) and an upper wire loop (20), which together define a substantially horizontal twin wire forming zone, which comprises the following web forming zones (a), (b) and (c): (a) In the area of the forming gap (G), a first suction zone (11a) placed inside the first forming roll (11), and immediately thereafter a second suction zone (11b) is placed in forming roll (11). The suction zones (11a, 11b) are placed in the first upper quarter of the first forming roll (11) at the side of the forming gap (G). The levels of negative pressure (P.sub.1, P.sub.2) in the suction zones are adjustable. (b) A forming shoe (12), which is provided with an open guide deck (26), the interior space in the shoe being divided into at least two subsequent suction chambers (12a, 12b, 12c), the levels of negative pressure (P.sub.a, P.sub.b, P.sub.c) effective in said suction chambers being arranged to be adjustable, preferably separately adjustable.

Abstract: A stationary drainage device for a papermaking machine is described including a drainage box which may have a plurality of vacuum chambers and a stationary curved cover formed by cover strips of ceramic material separated by drainage slots. The cover includes a central cover strip of greater width than the other cover strips on opposite sides thereof. A pressure roll presses the paper sheet and the porous conveyor transporting such sheet across the curved cover of the drainage device, against the curved upper surface of the central cover strip at a nip position spaced from the drainage slots and the other cover strips for greater dewatering efficiency. The stationary drainage device may be mounted at the output of the forming section as a stationary couch device or in the press section as a felt conveyor cleaning and dewatering device.

Abstract: A twin-wire former for the production of a web of paper from a fiber suspension. An upper endless loop of wire belt having a lower horizontal run and a lower endless loop wire belt having an upper horizontal run. Guide rolls support the wire belts to define a twin-wire zone. The upstream inlet wedge of the twin-wire zone is disposed at the outlet from a head box. The initial part of the path of the twin-wire zone has a gradual curvature convexly with respect to the lower wire belt, and in that initial portion are positioned guide tables, suction boxes and dewatering elements. This curved initial part is followed by a forming roll within the loop of the upper wire belt. The twin-wires wrap an arcuate sector of the lower region of the forming roll. A support roll follows the forming roll. The support roll is upraised sufficiently to wrap the twin-wires around the bottom of the forming roll and over an arcuate sector at the top of the support roll.