Patents Examined by Steve Alvo
  • Patent number: 7112256
    Abstract: A method for the continuous cooking of chemical pulp with the aim of achieving improved heat economy in a digester system having a vessel (1) for impregnation and a vessel (2) for cooking the impregnated cellulose chips. A part of the black liquor (14) withdrawn from the digester (2) is added at the beginning of a transfer system (4) to increase the temperature of the chips mixture in the transfer system (4). A fraction of the transport fluid (10) from the transfer system (4) that is continuously withdrawn from the impregnated chips fed into the top of the digester is returned to the impregnation vessel (1) at essentially the maintained transfer temperature.
    Type: Grant
    Filed: January 22, 2003
    Date of Patent: September 26, 2006
    Assignee: Kvaerner Pulping AB
    Inventors: Vidar Snekkenes, Lennart Gustavsson
  • Patent number: 7070677
    Abstract: The present invention relates to a method of and apparatus for treating pulp with filler. The method and apparatus according to the invention are especially well suitable for treating pulp with filler, the mixing of which to the pulp requires simultaneous treatment of the pulp with gas. The treatment of cellulose pulp suspension of the paper making industry and calcium hydroxide with carbon dioxide is presented as one preferred embodiment of the invention.
    Type: Grant
    Filed: November 14, 2001
    Date of Patent: July 4, 2006
    Assignee: Andritz OY
    Inventor: Kaj Henricson
  • Patent number: 7052578
    Abstract: Wood pulp is bleached using hydrogen peroxide as the oxidative bleaching agent in the presence of magnesium hydroxide or magnesium oxide. The bleaching process is carried out in the presence of magnesium hydroxide as the predominant, and preferably essential, source of alkali. The process optionally includes transition metal chelants, such as DTPA or EDTA in the bleaching slurry. The process eliminates the need for added caustic and silicate in such systems and can be carried out at or near neutral pH of 5.0 to 8.5.
    Type: Grant
    Filed: January 26, 2001
    Date of Patent: May 30, 2006
    Assignee: Martin Marietta Magnesia Specialties, Inc.
    Inventors: Mark T. Wajer, Aileen R. Gibson, Joseph Genco, Donna Johnson, Burton Branch
  • Patent number: 7001484
    Abstract: A process for peroxide bleaching of mechanical or high yield pulp, the process comprising adding to a pulp slurry at least one stabilizer for stabilizing low valency states of transition metal ions in the slurry; subsequently adding caustic soda to said slurry simultaneously with or subsequent to adding said at least one stabilizer; adding hydrogen peroxide to the slurry at a preselected point; and subjecting the slurry to preselected conditions to complete the bleaching process.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: February 21, 2006
    Assignee: University of New Brunswick
    Inventors: Yonghao Ni, Zhiqing Li
  • Patent number: 6969443
    Abstract: A process for making absorbent sheet material from recycle furnish includes treatment with a synergistic debonder composition. The debonder is capable of reducing tensile strength by 40 percent or more by way of a quaternary ammonium surfactant component and a nonionic surfactant component.
    Type: Grant
    Filed: December 7, 1999
    Date of Patent: November 29, 2005
    Assignee: Fort James Corporation
    Inventor: Bruce J. Kokko
  • Patent number: 6958108
    Abstract: The present invention relates to a modified fiber product and a method of producing same. According to the method, the cellulosic raw material is formed into a fiber suspension, into which components modifying the properties of the fibers are added, subsequent to which the fibrous material is dried in connection with, for example, web forming. According to the invention, alkyl derivative of cellulose is mixed into the fiber suspension in alkaline conditions, the derivative being at least partly dissolved in water, and the derivative is allowed to be sorbed into the fibrous material prior to drying such that the sorbed cellulose derivative can not be washed off with water. The strength properties or the water retention of paper and paperboard products can be improved by using the invention.
    Type: Grant
    Filed: April 30, 1999
    Date of Patent: October 25, 2005
    Assignee: M-real Oyj
    Inventor: Tapani Vuorinen
  • Patent number: 6958110
    Abstract: Apparatus for the production of cellulose paper pulps from vegetative masses, comprising: a tower for sterilizing the mass to form a culture medium; a first screw for mixing the sterilized mass with an inoculum and handling the same in a sterile environment; a first conditioning and reaction chamber for mixing and handling the inoculated mass in a sterile environment and controlled atmosphere of CO2 and O2, with controlled temperature and pH; a hydraulic pulper for the elementarization of the mass and its soaking up with suspensions of enzyme mixes; a hammer mill for the elementarization of vegetative material, to break up knots of stems and to pulverize leaves, detach bast from wood; a rotating tumbler having reels and counter reels for separating various fractions; a rotor compactor to reduce the volume of the vegetable mass and to remove air contained in the same; a second screw for mixing the compacted vegetetative mass with extracts containing enzymes and with water for handling in a sterile environment;
    Type: Grant
    Filed: January 23, 2002
    Date of Patent: October 25, 2005
    Assignees: Consiglio Nazionale Delle Ricerche, Universita' Degli Studi Della Tuscia
    Inventors: Giovanni Giovannozzi Sermanni, Pier Luigi Cappelletto, Ruggero Baldo, Antonio Porri, Alessandro D'Annibale, Claudio Perani
  • Patent number: 6958109
    Abstract: A method and apparatus for treating pulp being fed into a blow tank or a storage tank. A preferred embodiment is that the pulp is discharged from a batch digester (10) and fed either to the upper or lower part of a blow tank (20), depending on the consistency of the pulp being discharged from the digester.
    Type: Grant
    Filed: February 2, 2000
    Date of Patent: October 25, 2005
    Assignee: Sulzer Pumpen AG
    Inventors: Martti Heikkila, Kari Kovasin, Karl-Erik Róberg, Olavi Toukonummi
  • Patent number: 6946056
    Abstract: Method for enabling the paper pulp production process to be controlled in such a way that the hexenuronic acid content in the pulp can be minimized and the color reversion of the pulp and/or the pulp products thereby minimized. The method is based on measurements of the optical properties of a fiber containing substance or process stream in the wavelength region 232±5 nm and another wavelength interval. A significant value for the current hexenuronic acid content is formed by correcting the intensity in the spectrum around 232 nm by the corresponding optical quantity at the other wavelength interval. The content of the hexenuronic acid content that is determined by the analysis is then used for controlling conditions in the process stage.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: September 20, 2005
    Assignee: Kvaerner Pulping AB
    Inventor: Martin Ragnar
  • Patent number: 6942754
    Abstract: Xylooligosaccharide is produced from a lignocellulose pulp by enzyme-treating a lignocellulose pulp with hemicellulase, filtering the resultant reaction mixture to separate a liquid fraction from the enzyme-treated pulp, subjecting the separated liquid fraction to a permeation treatment through a separation membrane to separate a non-permeated fraction containing xylooligosaccharide-lignin complex with an increased concentration from a permeated fraction, collecting the non-permeated fraction, and separating and recovering xylooligosaccharide from the collected non-permeated fraction.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: September 13, 2005
    Assignee: Oji Paper Co., Ltd.
    Inventors: Yoshiya Izumi, Jun Sugiura, Hitoshi Kagawa, Naoya Azumi
  • Patent number: 6939439
    Abstract: Methods for producing chemical pulp from lignocellulose-containing material in processes for kraft pulp production are disclosed including charging the lignocellulose-containing material to a digester, initially treating the lignocellulose-containing material with an impregnation liquor, and then treating the impregnated lignocellulose-containing material with hot liquor and displacing calcium-containing spent liquor from the digester during that treatment, heating and cooking the heated lignocellulose-containing material to produce cooked lignocellulose-containing material and cooking liquor and displacing the cooking liquor from the digester using at least a portion of the displaced calcium-containing spent liquor.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: September 6, 2005
    Assignee: Metso Chemical Pulping Oy
    Inventors: Asko Paakki, Päivi Uusitalo, Mikael Svedman
  • Patent number: 6923887
    Abstract: Disclosed is a method for pulp bleaching. The method comprises the steps of providing a pulp sample for bleaching, the pulp sample stemming from a pulp producing process, providing a bleaching liquor comprising water and an organic component as solvent components constituting a bleaching medium, dissolved within are at least a bleaching agent, and a basic agent; and subjecting the pulp sample to the bleaching liquor for a predefined amount of time at predefined bleaching conditions. A preferred bleaching agent is hydrogen peroxide. The organic component amounts to at least 5% in weight of the bleaching medium.
    Type: Grant
    Filed: February 21, 2003
    Date of Patent: August 2, 2005
    Assignee: Alberta Research Council Inc.
    Inventor: George Pan
  • Patent number: 6913672
    Abstract: Chemical species (e.g., metaborate, carbonate, hydroxide and sulfide) in a boron-containing alkaline wood pulping liquor sample are determined quantitatively by (i) subjecting a first aliquot portion of the sample to a primary acid titration analysis to derive multiple equivalence points at different respective pH values; (ii) subjecting a second aliquot portion of the sample to an analysis to determine the quantitative presence of boron or sulfide ions therein, and then (iii) determining the quantitative presence in the sample of at least one of the chemical species. Wood pulping parameters may thus be determined on the basis of the quantitative presence of the chemical species to assist in process and/or quality control of the wood pulping operation.
    Type: Grant
    Filed: September 11, 2003
    Date of Patent: July 5, 2005
    Assignee: U.S. Borax Inc.
    Inventor: Wu-hwa Wesley Hsu
  • Patent number: 6899790
    Abstract: A process for producing high bulk cellulosic fiber exhibiting a durable elevated curl index includes: (a) concurrently heat treating and convolving cellulosic fiber pulp at elevated temperature and pressure at high consistency under conditions selected so as to preclude substantial fibrillation and attendant paper strength and fiber bonding development; and (b) recovering the pulp wherein the length weighted curl index of the treated fiber is at least about 20% higher than the length weighted curl index of the fiber prior to the heat treatment and convolving thereof. The curl imparted to the fiber persists upon treatment for 30 minutes in a laboratory disintegrator at 3000 rpm at 1% consistency at a temperature of 125° F. Moreover, the curl may be imparted to the fiber in a disk refiner at very short residence times, on the order of several seconds or less. In general, the process is carried out in the presence of saturated steam at a pressure of from about 5 to about 150 psig.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: May 31, 2005
    Assignee: Georgia-Pacific Corporation
    Inventor: Jeffrey A. Lee
  • Patent number: 6899791
    Abstract: A method and apparatus for pretreating or conditioning lignocellulose fiber containing feed material in preparation for conversion to pulp. Wood chips are pretreated under conditions of elevated temperature, pressure and humidity and subsequently compressed to cause destructuring of the fibers of the feed material. The pretreated wood chips are then converted to pulp using such methods as the ground wood pulping process or chemical digestion process.
    Type: Grant
    Filed: August 8, 1997
    Date of Patent: May 31, 2005
    Assignee: Andritz Inc.
    Inventor: Marc J. Sabourin
  • Patent number: 6884320
    Abstract: A method for producing and testing a fiber bed, includes a housing, a main inlet passage and a main outlet passage, a cavity in the housing in fluid connection with the inlet and outlet passages, a body rotatably arranged in the cavity, the body being arranged with a through-going passage having first and a second opening, a screen arranged in the through-going passage, and elements for measuring properties of the fiber bed. The method includes positioning the body so that the first opening is connected to the main inlet and the second opening is connected to the main outlet, creating a first passage, leading a fiber suspension through the first passage in order to produce a fiber bed on the screen, measuring the properties of the bed, rotating the body such that the second opening is connected to the main inlet and the first opening is connected to the main outlet and creating a flow through the first passage for removing the fiber bed from the screen through the outlet.
    Type: Grant
    Filed: March 25, 2002
    Date of Patent: April 26, 2005
    Assignee: Fibertracker AB
    Inventors: Hakan Karlsson, Per-Ivar Fransson
  • Patent number: 6881297
    Abstract: A device and process for aerating dispersions, particularly for flotation of pulp suspensions, in a de-inking process where the pulp suspension containing dirt particles is sprayed into a tank together with air. The air is injected at a minimum of two successive points and mixed with the suspension.
    Type: Grant
    Filed: March 12, 2003
    Date of Patent: April 19, 2005
    Assignee: Andritz AG
    Inventors: Bernhard Scherzinger, Helmuth Gabl
  • Patent number: 6881298
    Abstract: For a process and an apparatus for loading fibers contained in a pulp suspension with calcium carbonate, a calcium oxide and/or a medium containing calcium hydroxide is fed to the pulp suspension, and the so treated pulp suspension is further charged in several reactors with pure carbon dioxide or a medium containing carbon dioxide. The reactors can be connected in series and/or in parallel.
    Type: Grant
    Filed: February 19, 2003
    Date of Patent: April 19, 2005
    Assignee: Voith Paper Patent GmbH
    Inventors: Jörg Rheims, Klaus Doelle, Oliver Heise, Werner Witek
  • Patent number: 6866749
    Abstract: The invention concerns a method for bleaching different types of paper pulp in two steps at atmospheric pressure and at a temperature not higher than 100 DEG C. The first step consists in contacting the unbleached paste with a mixture of paracetic acid and performic acid. The second step consists in treating the bleached pulp derived from the first step, with a solution of soda and hydrogen peroxide. The resulting pulps exhibit a high index of whiteness and a degree of polymerisation close to unbleached pulps. The method is environmentally safe and non-polluting.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: March 15, 2005
    Assignee: Compagnie Industrielle de la Matiere Vegetale
    Inventors: Michel Delmas, Gérard Avignon
  • Patent number: 6841036
    Abstract: A system and process for the oxygen delignification of pulp consisting of a lignocellulose-containing material that has a mean concentration of 8-18% pulp consistency. The oxygen delignification takes place in a first stage with a short dwell time of about 3-6 minutes, at a low temperature of about 85° C. and under a low pressure of approximately 0-4 bar. A concluding stage has a longer dwell time of about 50-90 minutes, at a higher temperature of approximately 100° C. and under a higher pressure of about 8-10 bar.
    Type: Grant
    Filed: April 11, 2002
    Date of Patent: January 11, 2005
    Assignee: Kvaerner Pulping AB
    Inventors: Hakan Dahllof, Martin Ragnar