摘要:
Process of forming a headbox for a machine, which includes arranging a plurality of headbox channels into rows and columns, positioning a lamella between adjacent rows, fixing an end of the lamella at a fixing point, and arranging lamellar supports downstream of, relative to a headbox flow direction, the fixing point.
摘要:
Headbox for a machine and process for forming the same. The headbox includes a plurality of channels arranged in rows that extend across a width of the machine and in columns substantially perpendicular to the rows, at least one lamella positioned between adjacent rows, a fixing point for the at least one lamella, and lamellar supports positioned after the fixing point, relative to a headbox flow. This includes arranging a plurality of headbox channels into rows and columns, positioning a lamella between adjacent rows, fixing an end of the lamella at a fixing point, and arranging lamellar supports downstream of, relative to a headbox flow direction, the fixing point.
摘要:
Sheet formation system and method for reducing wavy edges in a fourdrinier machine. The system includes a headbox having a nozzle bring adapted to produce a pulp suspension jet across a width of the machine, at least one rotating screen positioned to receive the pulp suspension jet, and at least two deckle plates adjacent to the screen. The deckle plates may be adjustably positionable such that a distance between the deckle plates and a centerline of the screen is adjustable in a machine direction over a substantial portion of a length of the side shields. The method includes directing a pulp suspension jet onto the rotating shield between the deckle plates to form a web sheet, moving the web sheet in a machine direction, and adjusting a distance between the deckle plates as the web sheet is moved in the machine direction. The method also includes positioning the mechanical deckle plates having a flat surface being adapted to face the pulp suspension in the pulp suspension application area to form edges of the sheet being formed and bending the flat surface of the mechanical deckle plates as the formed sheet travels in a machine direction.
摘要:
Headbox that includes a turbulence generator including a plurality of essentially parallel rows of pipes and a jet including of an upper lip and a lower lip arranged to form a jet space and a jet outlet slit. A plurality of lamellae are arranged to subdivide the jet space, and the plurality of lamellae include end sections and lamella sections. The end sections are mounted between the plurality of essentially parallel rows of pipes, and at least some of the lamella sections are arranged to converge over a bend point in a direction of the jet outlet slit and, thereby, are angled toward a longitudinal axis of the turbulence generator.
摘要:
A sheet-forming system includes a separating wedge with a separating wedge protrusion in a range of 0.05 to 3.0 of the largest single gap width of at least two nozzle chambers. The separating wedge includes two separating wedge areas, each having one separating wedge angle, an upstream separating wedge starting area and a downstream separating wedge ending area. The two separating wedge angles assume different angles. The separating wedge starting angle of the upstream separating wedge initial area assumes a greater angle than the separating wedge ending angle of the downstream separating wedge end area. At least one separating wedge surface is a nonplanar transitional area between the two separating wedge areas. The fibrous material suspension free jet formed from at least two fibrous material suspension streams has a free jet length of 100 to 500 mm. The forming roll has a diameter of 1,200 to 2,500 mm.
摘要:
A headbox includes a feed device for feeding at least one fiber suspension, a perforated distribution pipe plate arranged immediately downstream thereof and having a plurality of channels arranged in lines and columns and an intermediate channel arranged downstream thereof extending over the width of the headbox and having a plurality of apparatuses for dosing a fluid in partial fluid streams to the at least one fiber suspension in an adjustable/controlled manner. The apparatuses are spaced apart from each other in the width direction of the headbox and the individual apparatuses include a plurality of dosing channels having respective dosing channel openings on the outlet side and a dosing channel length, arriving at different levels and being connected to a common supply channel. The headbox further includes a downstream turbulence generator having a plurality of flow channels arranged in lines and columns and a headbox nozzle which is directly contiguous to the turbulence generator and which has a nozzle gap. At least some sections of the channels of the perforated distribution pipe plate have a diffuser and the perforated distribution pipe plate has a length which is ≧0.5·√{square root over (partition)} area the partition area being the surface of the downstream perforated distribution pipe plate divided by the total number of the channels of the perforated distribution pipe plate.
摘要:
The invention relates to a sheet-forming system for a machine for producing a multilayer fibrous material web, comprising a multilayer headbox having a headbox nozzle, which has at least two nozzle chambers that are separated from one another by at least one separating wedge, and further comprising a gap former, which is connected directly downstream of the multilayer headbox and has two continuous revolving screens, the first screen of which runs over a circumferential area of a forming roll and the second screen of which runs over a circumferential area of a breast roll and then runs onto the first screen in the area of the forming roll to form a wedge-shaped material inlet gap. The sheet-forming system according to the invention is characterized in that the separating wedge has a separating wedge protrusion in a range of 0.05 to 3.0 of the largest single gap width of the at least two nozzle chambers; the separating wedge comprises two separating wedge areas, each having one separating wedge angle, an upstream separating wedge starting area and a downstream separating wedge ending area; the two separating wedge angles of the two separating wedge areas assume different angle values, wherein the separating wedge starting angle of the upstream separating wedge initial area assumes a greater angle value than the separating wedge ending angle of the downstream separating wedge end area, and at least one separating wedge surface of the separating wedge is provided as a nonplanar transitional area between the two separating wedge areas of the separating wedge; the fibrous material suspension free jet formed from at least two fibrous material suspension streams has a free jet length in the range of 100 to 500 mm, and the forming roll has a diameter in the range of 1,200 to 2,500 mm.
摘要:
The invention relates to a headbox which comprises a feed device feeding the at least one fiber suspension, a perforated distribution pipe plate arranged immediately downstream thereof and having a plurality of channels arranged in lines and columns, an intermediate channel arranged downstream thereof, extending over the width of the headbox and having a plurality of means for dosing a fluid in partial fluid streams to the at least one fiber suspension in a preferably adjustable/controlled manner, the means being spaced apart from each other in the width direction of the headbox and the individual means comprising a plurality of dosing channels having respective dosing channel openings and an opening center line, arriving at different levels and being connected to a common supply channel. The headbox further comprises a downstream turbulence generator having a plurality of flow channels arranged in lines and columns and a headbox nozzle which is directly contiguous to the turbulence generator and which has a nozzle gap. The headbox according to the invention has a system pressure loss which is substantially composed of a first pressure loss between the feed device and the intermediate channel and a second pressure loss in the turbulence generator, the second pressure loss and the first pressure loss being in a ratio ranging from 8:1 to 1:1, preferably from 4:1 to 1:1, particularly from 2:1 to 1:1.
摘要:
The invention relates to a dual-layer material ramp for a machine for producing a dual-layered fibrous web, in particular a dual-layered paper or cardboard web, from two fibrous suspensions, comprising a material ramp nozzle with two nozzle spaces extending along the width and separated from one another on the inside by a separating wedge, said nozzle spaces guiding a respective fibrous suspension during operation of the dual-layer material ramp as fibrous suspension streams and coming together, each of said nozzle spaces comprising an upstream feed device, a downstream outlet gap with a gap width, said gap extending along the width and an outer wall on the outside, wherein the separating wedge comprises two separating wedge surfaces that are contacted by the respective fibrous suspension stream during operation of the dual-layer material ramp. The dual-layer material ramp according to the invention is characterized in that the separating wedge comprises two separating wedge areas, each having a separating wedge angle, an upstream separating wedge starting area and a downstream separating wedge end area, that the two separating wedge angles of the two separating wedge areas assume different angular values, wherein the separating wedge starting angle of the upstream separating wedge starting area assumes a greater angular value than the separating wedge end angle of the downstream separating wedge end area, and that a non-planar transition area is provided between at least one separating wedge surface of the separating wedge between the two separating wedge areas of the separating wedge.
摘要:
A headbox for a machine for producing a fibrous material web, in particular a paper or cardboard web, includes: a central assembly preferably forming the carrier elements of a turbulence generator, said assembly having a table leaf on the bottom side; and a headbox nozzle adjoining directly downstream in the machine running direction and extending in the machine transverse direction, said nozzle comprising at least one lower and one upper continuous nozzle wall extending over the machine width. The lower nozzle wall of the headbox nozzle of the headbox includes a lower lip plate, in particular a lower lip carrier plate, which is connected, in particular welded, to the table leaf of the central assembly by means of ribs extending in the machine running direction and spaced apart in the machine transverse direction. The ribs are designed in an elastic or pliable manner in the machine transverse direction.