摘要:
A method in the regulation of a pulp suspension flow through the headbox of a paper machine/board machine wherein an additional flow is introduced into the pulp suspension at different points across the width of the headbox. The concentration of the additional flow is regulated by a mixer unit which includes a displaceable distributor part such that when the mixing ratio is being regulated, the flow resistances of the component flows, of the additional flow, entering into the mixer unit are adjusted by displacing the distributor part of the mixer unit in a chamber of the mixer unit.
摘要:
The multi-cylinder dryer of a papermachine comprises a first tier of cylinders, wherein a web travels supported by a first dryer wire on the cylinders of the first tier of cylinders, as well as a second tier of cylinders, wherein the web travels supported by a second dryer wire on the cylinders of the second tier of cylinders. Upon passing around its wire guide roll, each dryer wire forms a loop having at least one section, along which the first or second wire, respectively, is free from the web and which in this wire traveling direction is immediately upstream of a point, at which the first or second wire is received on the first or second guide roll. Along a wire section between a cylinder and the guide roll, a nozzle inside the respective wire loop is used blowing air through the free section of dryer wire into a pocket between it and a cylinder of the opposite tier of cylinders for ventilating the pocket through a plenum zone formed between an air guiding surface located inside the respective wire loop downstream of the nozzle in the wire traveling direction, and the free section.
摘要:
The invention relates to a closed press section in a paper machine and comprises a compact combination of press rolls. Several of the rolls define press nips with each other, between which nips the web has a closed draw supported by the face of a fabric. The press section has a center roll in connection with which a press nip or press nips are provided. A closed loop of a transfer band is passed around the center roll. The web is transferred on an outer face of the transfer band after the last press nip in the compact combination of rolls as a closed and constantly supported draw onto a drying wire in a drying section following after the press section. The transfer band loop is made of a transfer band fabric that substantially does not receive water and does not rewet the web. The web-adhesion properties of the outer face of the transfer band fabric are chosen so that, after the last nip, the web follows the transfer band fabric, and so that the web can be transferred as a fully closed draw onto the drying wire. In connection with the loop of the transfer band fabric, means for conditioning of the band and/or safety devices are provided, by whose means an adequate operation of the transfer band fabric is maintained.
摘要:
The invention relates to a method and device for stabilizing a paper web in a group of cylinders in the dryer section of a paper machine. The group of cylinders are arranged in a row of drying cylinders and a corresponding row of leading rolls or equivalent placed as interlocked with the drying cylinders. The group of cylinders is provided with a single-wire draw so that the heated drying cylinders in the group are placed outside the loop of the drying wire and the leading rolls in the group are placed inside the loop of the drying wire. The stabilization device is arranged in the area between adjacent drying cylinders and the leading roll or equivalent placed as interlocked between the adjacent drying cylinders in the group of cylinders. Air is blow from the device and directed in the direction opposite to the running direction of the paper web. A nozzle opening of the stabilization device is shaped so that the air flow follows a substantially smooth face of the stabilization device while, at the same time, ejecting surrounding air along with it. In preferred embodiments, the smooth face is substantially parallel to the drying wire and the group of cylinders is formed as a compact geometry.
摘要:
A method for drum winding a web and a drum winder in which a roll that is being formed, i.e., onto which a web is being wound, is supported on winding drums. At least a part of the area that surrounds the roll being formed is subjected to a pressure lower than the pressure that prevails in a gap formed by the roll being formed and the winding drums, whereby a floating effect is produced on the roll being formed. The drum winder is preferably placed in a vacuum chamber.
摘要:
A method and apparatus for opening a nip in an extended-nip press in which a nip is formed by a pair of rolls. A loading shoe of the loading members of an extended-nip press roll in the nip is shifted to an open position and apart from the glide-belt mantle when the nip is opened. An inner end-flange part of the end flange is operatively coupled with bearing means of a glide-belt mantle and is rotated in a direction parallel to the face of a central axle of the extended-nip press roll, whereby the glide-belt mantle is removed from contact with a back-up roll since a central axis of the end-flange part is located at a distance from a central axis of the extended-nip press roll.
摘要:
The invention concerns an adjustable-crown roll having a stationary roll axle which is supported on the machine frame by means of articulated bearings, and a roll mantle which is arranged to revolve on the axle. Hydrostatic loading members or an equivalent pressure fluid chamber or series of chambers are arranged in the space between the axle and the roll mantle. By means of the loading members or equivalent, the profile of a nip formed with a counter-roll of the roll is regulated. A support bushing arranged concentrically with the roll mantle is attached to one end of the roll mantle and revolves along with the roll mantle. A bearing is installed on the support bushing. The bearing receives axial forces from the roll mantle and transfers the same to the machine frame through the non-revolving bearing block or housing of the bearing. The bearing is arranged, in the axial direction, outside the roll, whereby the roll is suitable for use as a hot roll.
摘要:
A method and device for the regulation of a pulp suspension flow in a multi-layer headbox and a multi-layer headbox for a paper machine/board machine. For the formation of different layers in the web, at least two pulp suspensions having different pulp concepts flow through the multi-layer headbox. The flow of a pulp suspension that forms one of the layers in the web is regulated by regulating the component flows that constitute this flow and regulating the concentration of the component flows independently from one another. In this manner, i.e., by regulating only this the particular layer, the total flow of the pulp suspension leaving the headbox is regulated.
摘要:
A method and apparatus for identifying a moving web in a paper making machine are disclosed. The method includes of the steps of illuminating the web with the light from a transmitter, reflecting the transmitted light off the web, receiving the reflected light with a light transducer to produce an electrical signal corresponding to the intensity of the received light, and identifying the moving web based on the received signal. The intensity of the transmitted light is adjusted so that the received light signal from the transducer is normalized with respect to an optimum value. The apparatus includes a light transmitter, a light receiver, and a control and identification circuit which identifies the web based on a signal from the light receiver, and which adjusts the intensity of the light transmitter to optimize the reception of the signal from the light receiver in order to minimize the effects of environmental interference.
摘要:
A suction roll for a paper machine in which a stationary suction shoe is arranged inside a revolving mantle loop and is connected to a source of negative pressure. The mantle loop is a substantially water-receiving and permeable fabric-sock loop that receives water and is, in a preferred embodiment, supported by means of guide members arranged inside the loop. The suction shoe is provided with a permeable guide deck against which the inner face of the fabric-sock loop glides.