Abstract: The invention relates to a roll press including at least three rolls forming several press nips for the treatment of a web of material. One press roll comprises a very flexible roll shell which is rotatable around a fixed support and is mounted on the support by at least one support element which has a concave support surface for defining a wide press nip with a cylindrical backing roll. The backing roll forms an additional press nip with at least one not sag-controlled roll. To obtain as uniform as possible a press nip between the backing roll and at least one additional roll which is without sag control, the circumference of the roll shell of the backing roll decreases axially towards its ends, i.e., that roll may be crowned.
June 19, 1997
Date of Patent:
August 4, 1998
Voith Sulzer Papiermaschinen GmbH
Rainer Bentele, Christian Schiel, Wolf Gunter Stotz
Abstract: A multi-ply paper web forming apparatus utilizes first and second forming wires which travel in a co-running path for a portion of their length and which form a throat into which an aqueous slurry of paper pulp fibers is introduced. The slurry is dewatered between the co-running first and second forming wires upwardly and downwardly to quickly produce a substantially formed, but still moist, top ply web which is carried on the second forming wire onto a base ply web which has previously been formed on the wire of a single wire former. The first surface of the top ply web is brought into ply bonding engagement with the surface of the base ply web to produce a composite multi-ply web which has superior overall ply bond, retention and dryness before leaving the web forming section of a papermaking machine.
Abstract: In a pulping apparatus including a pulper with a rotor near the bottom therein, the pulper has a sluice outlet at the bottom for acceptable pulp suspension. Above the rotor at a corner of the pulper is a second outlet for suspension and dirt. A conduit leads from the second outlet to a horizontally oriented withdrawal apparatus chamber having a suspension agitating rotor at the end of the chamber opposite the entrance for pulp thereinto. A tangential outlet from the withdrawal apparatus chamber lead to a rotary, perforated sorting drum which permits exit of acceptable suspension and which has a rejected suspension and dirt outlet. A valve in the inlet to the withdrawal apparatus chamber is periodically and cyclically opened to permit periodic replacement of the suspension in the withdrawal apparatus chamber, and the suspension which has been agitated in the withdrawal apparatus chamber then moves to the sorting drum.
August 27, 1986
Date of Patent:
April 4, 1989
J. M. Voith GmbH
Theodor Bahr, Helmut Thumm, Walter Musselmann
Abstract: A method and apparatus for decomposing waste paper in a storage tank (tower) under the effect of chemicals with a high stock concentration (high-consistency stock method), including the rotation of the paper pulp together with dilution and a vigorous extensive disintegration of the waste paper or rags by a slushing rotor in the lowest part of the storage tank (tower).
Abstract: A plurality of stages of parallel twisted plates extend in a slurry passage adjacent to a slice outlet of a head box in the direction of papermaking slurry flow therethrough and are spaced apart from each other by a predetermined distance. The twisted plates directly cause the slurry flowing through the head box to swirl. Adjacent vortex flows of the slurry interfere with each other, resulting in the violent agitation of the slurry.
Abstract: An apparatus having a liquid-permeable belt for receiving cellulose pulp, a liquid supply device for discharging treatment liquid on the cellulose pulp, and a container extending across the entire width of the belt for collecting treatment liquid penetrating the belt. The container is adapted to maintain a treatment liquid level at such a distance from the belt so that the formation of foam from treatment liquid is reduced. The container includes a liquid outlet for discharging the treatment liquid and a vapour outlet for discharging vapours and gases from the bottom of the container. The vapour outlet communicates with a passageway within the container, which passageway is formed as a pipe or is partially defined by a container wall. A deflector can be provided on the container for operatively deflecting treatment liquid away from the passageway.
Abstract: Fiberizer efficiency is improved by providing an inline control valve at the fiberizer feed inlet which automatically provides the fiberizer with make-up air proportional to the pressure differential between the fiberizer outlet and inlet. The make-up air tends to distribute the feed material more evenly within the feed inlet and provides a constant fiber/air ratio within the fiberizer.
Abstract: A pintle unit and method of closing a seam in a papermakers felt which provides a tight closure along the full length of the seam. The seam is closed with a pintle unit made up of a plurality of pintle elements which are tapered and pulled into the seam to interact in a wedging fashion. The pintle elements are tapered for a length at least as long as the width of the seam so that when wedged in the seam a pintle unit of substantially uniform size across the full width of the felt is provided.
Abstract: A method and apparatus for removing stringy contaminants from a pulp in a wastepaper recovery system having a pulping vat with an elongate helically shaped rod in the vat with means for causing a relative rotation between the stock and the helical rod so that long slender contaminants will be captured and climb the rod. In one form, multiple helices are employed and the rods may be driven in rotation, or the stock caused to rotate about the helix by other means.
Abstract: Method and apparatus in the headbox of a paper machine and in its approach pipe system. In the headbox, pulp suspension is fed through the approach pipe system and a pressure screen arrangement, if any, to a distributing header part, from which the pulp suspension flow is conducted through a turbulence generator section and further to a lip section. A pulp suspension jet is discharged from a lip aperture of the lip section onto a forming wire or into a throat defined by a pair of forming wires. At least part of the approach pipe system, the distribution header part, and the turbulence generator section are arranged to have two or several substantially parallel pulp suspension flow passages. The different passages operate substantially simultaneously in parallel, when the headbox has been set to operate in a higher flow rate range.
Abstract: The invention concerns a dewatering band press. The wires (2) in the press are wider than the rolls (1), and in view of sealing the edge of the pulp web (3), two rails (4) are placed outside the ends of the rolls, the wires running between the said rails, and a sealing beam (5) is placed between the rails and the wires. The solution is durable and reliable, because it has no readily worn abrading parts.
Abstract: A coating press apparatus is disclosed for coating a first and second side of a pressed web formed in a forming section of a papermaking machine. The apparatus includes a first press roll which defines a smooth imperforate first surface. The first surface cooperates with the first side of the web. A first backing roll cooperates with the first press roll for defining therebetween a first nip for the passage therethrough of the web. A first felt supports the web during passage through the first nip and a first short-dwell coater applies a coating directly to the surface of the first press roll upstream relative to the first nip such that a smooth and even first layer of the coating substance is applied to the first side of the web during passage of the web through the first nip.
Abstract: A closed press section of a paper machine for removing water from the paper web passing therethrough. A compact press roll combination is provided with several press nips being formed in association with various rolls, and between which the web runs supported by roll surfaces without substantially long free draws. The press section comprises a first nip formed by two press suction rolls, through which two felts pass, the first felt functioning as a pick-up felt and moving the web from a pick-up point through the first press nip, and the second felt moving the web from the first nip to the second press nip of the press section. The second press nip is formed at a lower circumference of a smooth-surfaced, large diameter center roll, through which the second felt runs.
Abstract: Fastening of a profile bar to adjustment spindles at a discharge opening of a head box of a paper machine. A series of fastening holes or recesses are made into one edge of the profile bar and provided with chamferings. In the end of the adjustment spindles situated next to the discharge opening, a recess is provided with a series of screws being fitted in one side thereof. These screws are provided with ends coresponding to the chamferings in the fastening holes of the profile bar. A second set of screws coaxial with the first set of screws are provided in an outer wall of the recess, with inner ends of the second set of screws being provided with parts corresponding to the outer chamferings of the fastening holes in the profile bar.
Abstract: An extended nip press has a looped belt mounted over a shoe having a concave surface which presses the belt against a mating surface on a roll to provide an extended nip. The shoe has a support which is movable in a skewing sense relative to the longitudinal axis of the roll. Lateral movement of the belt is monitored. When it has moved beyond predetermined limits in either direction, the shoe is skewed to alter the frictional forces on the belt as it passes over the shoe's surface. This controls the position of the belt and keeps it centered in the nip.
Abstract: A two-wire paper forming apparatus wherein the co-running forming wires converge over a forming roll and diverge over a couch roll downstream of the forming roll. A curved forming zone begins where the forming wires converge over the forming roll to receive a stock stream, and extends to before the couch roll whereby the forming roll in conjuction with a pair of convexly curved dewatering shoes disposed against the forming wires between the forming roll and the couch roll form the web while providing improved retention and formation.
Abstract: A method for producing mechanical pulps which are useful for producing coated light weight paper, magazine paper and the like, is disclosed, which includes preheating lignocellulose-containing material in the presence of impregnation chemicals, refining the preheated lignocellulose-containing material utiilizing a pair of counter-rotating refining discs under pressure, bleaching the thus produced partially refined lignocellulose-containing material, and refining the bleached material in a second refining step utilizing a pair of refining discs, one of which is stationary and the other which is rotating under pressure.
May 28, 1987
Date of Patent:
December 6, 1988
Sunds Defibrator Aktiebolag
Michael Jackson, Knut O. Danielsson, Bo G. S. Falk
Abstract: Skimming blades in papermaking machines have a dewatering surface 4 adjoining the supporting surface 3 supporting the wire 1. To sustain the desired microturbulence of the fiber suspension 2 on the wire 1, the dewatering surface 4 is provided with troughs 7. The troughs 7 have a wavy shape, in which the wave crests 5 have a smaller radius r than the wave valleys 6.
Abstract: The instant invention is directed to a method for deinking cellulosic fibrous material impregnated with ink wherein a mixture of said material and water is stirred in the presence of a deinking agent, the improvement wherein the deinking agent is a hydrolyzed copolymer of dimethyldiallyl ammonium chloride and acrylamide.