Patents Assigned to Valmet Fibertech AB
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Patent number: 6464826Abstract: Method is disclosed for treating wood chips including a heater for preheating the wood chips in the presence of steam, a beater to mechanically process the wood chips into wood fibers, a cyclone for separating the wood fibers from steam and volatile organic substances produced in the beater, a blower line for transporting the wood fibers, steam and volatile organic substances from the beater to the inlet of the cyclone, a drying conduit connected to the lower outlet of the cyclone for carrying wood fibers therefrom, a sluice valve associated with the lower outlet of the cyclone for controlling the removal of the wood fibers from the cyclone, and a processing conduit connected to the upper outlet of the cyclone for the steam and the volatile organic substances whereby the volatile organic substances separated in the cyclone can be separated and heat associated with the steam separated in the cyclone can be recovered.Type: GrantFiled: February 18, 2000Date of Patent: October 15, 2002Assignee: Valmet Fibertech ABInventors: Christer Säfström, Carl-Johan Söderberg, Göran Lundgren
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Patent number: 6461505Abstract: Apparatus is disclosed for dewatering aqueous suspensions including a pair of rotatable rolls forming a nip therebetween, so that the aqueous suspension can pass downwardly through the nip and be dewatered by removing a filtrate from the suspension, and the dewatered suspension can pass downwardly from the nip, at least one of the rolls being liquid permeable, and at least one screen adjacent to the roll and disposed below the nip, the screen is separated from the roll by a predetermined distance and extends along its length, the predetermined distance being a sufficient distance so that a film of filtrate on the roll passes between the roll and upper end of the screen on one side of the screen and the dewatered suspension passes on the other side of the screen so that the filtrate is prevented from contacting the dewatered suspension below the nip.Type: GrantFiled: May 4, 2001Date of Patent: October 8, 2002Assignee: Valmet Fibertech ABInventors: Magnus Danielsson, Jörgen T Lundberg
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Patent number: 6454687Abstract: Apparatus for attachment to a press roll is disclosed, the apparatus including an edge ring extending around the edge of the press roll, the edge ring including a number of edge ring sectors dividing the edge ring diametrically and the edge ring sectors including a radial outer portion and a radial inner portion, the radial outer portion including a hook-shaped portion to form a cap joint with the edge of the press roll.Type: GrantFiled: December 30, 1999Date of Patent: September 24, 2002Assignee: Valmet Fibertech ABInventor: Stefan Mattsson
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Patent number: 6450764Abstract: Apparatus is disclosed for pumping a pulp suspension including a housing and an impeller including a central hub, a wheel disk surrounding the central hub, and pump blades extending radially from the central hub along the wheel disk, which includes at least one opening for discharge of an entrained gas from the pump suspension, a vacuum pump at the rear face of the impeller, and vacuum pump blades mounted for rotation within the vacuum pump housing, which includes an outer wall which is eccentrically disposed with respect to the vacuum pump blade, and a rear wall which includes a suction port for receiving the entrained gas, and with the vacuum pump housing mounted adjacent to the central hub to provide a gap therebetween, so that vacuum pump housing is axially adjustable so that the gap can be altered by axial adjustment of the vacuum pump housing.Type: GrantFiled: December 15, 2000Date of Patent: September 17, 2002Assignee: Valmet Fibertech ABInventors: Peter Danielsson, Kjell Forslund
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Patent number: 6432274Abstract: Apparatus is disclosed for handling a web including a pair of juxtaposed press rolls providing a nip therebetween, a coarse shredder trough disposed above the nip to receive the web from the nip, and a doctor arrangement for transferring the web from the outer surfaces of the press roll including a doctor support extending longitudinally of the pair of press rolls and a plurality of doctor blades attached to the doctor supports and extending in abutment with the outer surfaces of the press rolls, the doctor arrangement being supported by the coarse shredder trough whereby the doctor blades form a rigid structure for the plurality of doctor blades.Type: GrantFiled: March 23, 2001Date of Patent: August 13, 2002Assignee: Valmet Fibertech ABInventor: Leif Ödmark
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Patent number: 6393688Abstract: Methods and apparatus are disclosed for de-wiring bales tied by metal wires. The method includes moving the bales along a conveyor, stopping movement of the bales and clamping opposite sides of the bales between a pair of clamping units moving perpendicularly to the direction of the conveyor to clamp the opposite sides of the bales therebetween, cutting the metal wires on one side of the bales by means of a cutting tool forming part of one of the clamping units, seizing the metal wires on the other side of the bales and winding up the seized metal wires by means of a gripping and winding tool forming part of the other clamping unit, and discharging the wound-up metal wires from the gripping and winding tool.Type: GrantFiled: June 26, 2000Date of Patent: May 28, 2002Assignee: Valmet Fibertech ABInventor: Per-Olof Axner
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Patent number: 6361650Abstract: Processes are disclosed for processing low consistency newsprint pulp including refining the pulp in a first refiner to a consistency of greater than 2%, screening the processed pulp with a slotted screen basket with a slot width of from 0.05 to 0.15 mm, with the withdrawal of the primary reject portion being greater than 50%, withdrawing the accept portion for further processing, dewatering the reject portion to provide a high consistency pulp, refining the high consistency pulp in a second refiner, screening the processed high width consistency pulp with a slotted screen basket having a slot of less than 0.15 mm, and combining the two accept portions for the further processing steps.Type: GrantFiled: August 21, 2001Date of Patent: March 26, 2002Assignee: Valmet Fibertech ABInventors: Ove Danielsson, Bo Falk, Ulf Karlsson, Kenneth Kjellström
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Patent number: 6357144Abstract: Method for drying wood raw material (10) by means of hot gases (20) supplied to the drying process, in which VOC, apart from water, evaporate from the wood raw material into the gases. The drying process is divided and carried out in at least two sub-steps (I, II), from which process gas (22, 33) is removed separately, and the drying process is thus controlled that VOC evaporate during one of the sub-steps, and the VOC are concentrated to this sub-step. The temperature of the gas containing VOC is increased to a temperature exceeding 180° C. before VOC are oxidized catalytically at said elevated temperature, in order to reduce the discharge of VOC from the drying process.Type: GrantFiled: February 8, 2000Date of Patent: March 19, 2002Assignee: Valmet Fibertech ABInventors: Lars Nilsson, Stefan Backa, Ulf Persson
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Patent number: 6279201Abstract: Apparatus is disclosed for separating particles disposed in a carrier gas being delivered from a distributor to a moving web including a roller, a supply conduit for supplying the particles dispersed in the carrier gas substantially tangentially to the roller at a first speed, the roller rotating at a second speed which is substantially greater than the first speed whereby the particles are separated from the carrier gas, the roller including a discharge opening for discharging the particles toward the moving web and a return line for recycling the carrier gas. A method for separating particles dispersed in a carrier gas is also disclosed.Type: GrantFiled: September 19, 2000Date of Patent: August 28, 2001Assignee: Valmet Fibertech ABInventors: Stellan Jonasson, Heikki Salo, Lars-Erik Johansson
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Patent number: 6276622Abstract: Refining disks are disclosed including a plurality of ribs generally extending outwardly towards the outer end of the disk across its surface, the plurality of ribs having a uniform width and being curved with the shape of an involute arc with circular evolutes. Disk refiners including such refining disks are also disclosed.Type: GrantFiled: March 13, 2000Date of Patent: August 21, 2001Assignee: Valmet Fibertech ABInventor: Lars Obitz
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Patent number: 6257413Abstract: Screen panels are disclosed which are adapted to form a portion of a screening cylinder for screening fibrous material. The screen panels are unitary and made of wear-resistant material including a plurality of axially extending grooves on the outer surface of the screen panel, a plurality of slit-shaped screening orifices disposed at the bottom of the axial grooves, at least one support ring extending circumferentially across the surface of the screen panel and integral therewith, and a flange is formed at the sides of the screen panel so that the screen panels can be assembled together without the use of welding.Type: GrantFiled: April 27, 2000Date of Patent: July 10, 2001Assignee: Valmet Fibertech ABInventor: Mika Tolvanen
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Patent number: 6241102Abstract: Apparatus is disclosed for screening fiber suspensions including a housing, an annular screen disposed within the housing, a rotor disposed within the annular screen for rotating relative to the annular screen, pulsation wings disposed between the outer surface of the rotor and the annular screen for relative rotation with the rotor, an inlet for the fiber suspension to feed the fiber suspension to one end of the screening zone, an accept outlet for a portion of the fiber suspension which passes through the annular screen, a reject outlet for a portion of the fiber suspension which does not pass through the annular screen, and a dilution liquid nozzle for supplying a dilution liquid to the screening zone between the rotor and the annular screen, the dilution liquid nozzle disposed proximate to the reject outlet and directing the dilution liquid into the screening zone along the outer surface of the rotor.Type: GrantFiled: June 16, 2000Date of Patent: June 5, 2001Assignee: Valmet Fibertech ABInventors: Erkki Lindberg, Tauno Laakso
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Patent number: 6221265Abstract: Methods for the concentration of a dilute material such as a fiber suspension are disclosed including enclosing the dilute material between a first straining belt and a second straining belt both moving through endless paths, and in which the width of the first straining belt is greater than the width of the second straining belt, and the method includes causing the longitudinal edges of the first straining belt to overlap the longitudinal edges of the second straining belt in an initial concentration stage, unfolding the longitudinal edges of the first straining belt and then further compressing the concentrated layer produced against the first straining belt in a further concentration stage. Apparatus for carrying out this method is also disclosed.Type: GrantFiled: June 28, 2000Date of Patent: April 24, 2001Assignee: Valmet Fibertech ABInventor: Ebbe Hodén