With Washing Patents (Class 162/60)
  • Patent number: 7198695
    Abstract: The invention relates to a method for separating hemicelluloses from a biomass containing hemicelluloses. The method includes the steps of: a) extracting the hemicelluloses from the biomass containing hemicelluloses by treating them with a complex compound in an aqueous solution, and forming a soluble hemicellulose complex, and b) separating the complexed hemicelluloses from the biomass. The method is especially suitable for producing high-quality chemical conversion pulp from raw cellulose. The products produced with the method of the invention have a high degree of purity, and the method is extremely economical and causes few emissions. Hemicelluloses in a pure form can be obtained as by-products of the method.
    Type: Grant
    Filed: February 8, 2002
    Date of Patent: April 3, 2007
    Assignee: Rhodia Acetow GmbH
    Inventors: Gerhard Kettenbach, Armin Stein
  • Patent number: 7156952
    Abstract: The invention relates to a method and arrangement for alkaline oxygen delignification of cellulose pulp. By adding alkali in the final phase of the oxygen delignification one can ensure that an optimal predetermined end-pH is obtained. This provides advantages in the subsequent bleaching since the bleachability is substantially improved in the form of reduced need for bleaching chemicals.
    Type: Grant
    Filed: September 13, 2004
    Date of Patent: January 2, 2007
    Assignee: Kvaerner Pulping AB
    Inventor: Martin Ragnar
  • Patent number: 7081184
    Abstract: A process for making a pulp product that has a low COD is comprised of soaking and washing pulp in alkaline water for a sufficient time so that the COD after soaking and washing is less than or equal to 2.0 kg/1000 kg of dry pulp. The process includes repetitively soaking and washing an unbleached pulp in alkaline water that is never allowed to drop below pH 7.0. In this process, the pulp is soaked and washed for a total of at least 220 minutes at an elevated temperature to produce the pulp product that has a low COD.
    Type: Grant
    Filed: December 26, 2002
    Date of Patent: July 25, 2006
    Assignee: Weyerhaeuser Company
    Inventors: Brian Wester, Michael D. Vrbanac, Julie A. Reimer, Peter K. Lau, Brian E. Dennis, David W. Bickell
  • Patent number: 7077931
    Abstract: The method is for bleaching cellulose pulp in a bleach line that has at least two bleaching steps. The filtrate distribution is led up through the bleaching line counter-currently to the flow of cellulose pulp established in the bleaching line. A single joint main conduit is used for the bleaching steps. Wash filtrates obtained from the wash steps, used after or before the bleaching step, are led in conduits to branch locations on the train conduit that are positioned downstream of the branch location for drawing off of wash and/or dilution liquor for the wash step in question. All branch points in the joint main conduit are in fluid communication with one another along the main conduit.
    Type: Grant
    Filed: January 13, 2004
    Date of Patent: July 18, 2006
    Assignee: Kvaerner Pulping AB
    Inventors: Vidar Snekkenes, Lennart Gustavsson
  • Patent number: 7044307
    Abstract: A drum type paper stock refine screen is provided which is capable of efficiently filtering a refined paper stock to the outside of a laterally suspended rotary drum and efficiently discharging foreign matter to the outside of the drum while rotating the drum. The drum type paper stock refine screen includes a lower water infiltration zone formed by infiltrating a lower circular part on one end side of a laterally suspended rotary drum in a water tank, a non-water infiltration zone continuous with the lower water infiltration zone on the other end side of the rotary drum, and a paper stock injection port for injecting a paper stock in the lower water infiltration zone.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: May 16, 2006
    Assignee: Sakae Kohki Co., Ltd.
    Inventors: Eiichi Kamo, Nobuyuki Kamo
  • Patent number: 7018509
    Abstract: This invention relates to an improved process for manufacturing bleached thermomechanical aspen pulp having reduced yellow after treatment with aluminum based chemicals such as alum which are used in paper making processes. In this improved process the pulp is washed prior to, after or between the bleaching stages or a combination of the foregoing.
    Type: Grant
    Filed: August 31, 2002
    Date of Patent: March 28, 2006
    Assignee: International Paper Co.
    Inventors: Robin R. Kilgannon, Robert J. Kane, Eileen M. Joy, Anil K. Dewan
  • Patent number: 7018510
    Abstract: The present invention relates to an environment friendly, safe, and efficient four-step method of bio-bleaching Kraft pulp using bacterial strains of accession no. MTCC 5096, MTCC 5094, MTCC 5095, and MTCC 5098, a microbial consortium comprising a synergistic mixture of ligninolytic bacterial isolates of accession no. MTCC 5094, MTCC 5095, and MTCC 5098, bacterial strains of accession Nos. MTCC 5096, MTCC 5094, MTCC 5095, and MTCC 5098, and a process of preparing an inoculum of the bacterial isolate of accession no. MTCC 5096, further, a process for the preparation of a consortium comprising the ligninolytic bacterial isolates of accession nos. MTCC 5094, MTCC 5095, and MTCC 5098, in addition, a process for the preparation of pulp suspension for the bio-bleaching.
    Type: Grant
    Filed: March 21, 2003
    Date of Patent: March 28, 2006
    Assignee: Council of Scientific and Industrial Research
    Inventors: Rita Kumar, Anil Kumar
  • Patent number: 6986828
    Abstract: A process for producing microcrystalline cellulose. The process comprising the following steps: a) preparation of a pulp by repulping, b) pressing of the pulp obtained in a), c) decompaction of the pulp obtained in b), d) feeding of the pulp obtained in c) into a pre-heated reactor, e) cooking of the pulp at a temperature, a time and a pressure allowing to obtain a pulp having a desired degree of polymerization, f) cooling and partial controlled depressurization of the reactor by purging the reactor, followed by a water injection into the jacket and directly into the reactor, g) filtering the pulp obtained in f), h) bleaching of the pulp obtained in g), and i) drying the pulp obtained in h). The process allows the application of a controlled depressurization in step f), which in turn allows to keep the natural texture of the fibers and to obtain a cellulose having a low degree of polymerization.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: January 17, 2006
    Assignee: Kemestrie Inc.
    Inventors: Paul Jollez, Esteban Chornet, Sylvain Cloutier
  • Patent number: 6966970
    Abstract: The invention relates to a method for supplying washing liquid to a digester (1) for cellulose pulp and a subsequent diffuser washing device (2a, 2b). A high, disturbance-free production capacity can be obtained by using a common feed pump (P1) which, via a main feed line (10), supplies both the diffuser washing device and the digester with washing liquid in parallel. The first pump (P1) establishes a pressure on the washing liquid which is in the interval 2–6 bar, and is preferably 4 bar, while the second pressure level, which is established by the diffuser pump device (P2a, P2b), is in the interval 6–12 bar, but is at least 2 bar higher than the first pressure level, and the third pressure level, which is established by the digester pump (P3), is in the interval 12–25 bar The system becomes self-regulating in the event of any operational disturbances in the flow of washing liquid and, if the pumps are appropriate, a countercurrent flow of washing liquid through the system is essentially maintained.
    Type: Grant
    Filed: April 29, 2002
    Date of Patent: November 22, 2005
    Assignee: Kvaerner Pulping AB
    Inventors: Vidar Snekkenes, Lennart Gustavsson
  • Patent number: 6946072
    Abstract: A method for washing a fibre suspension with washing liquid, in which, in accordance with the invention, the fibre suspension is introduced into an annular treatment channel (24) that has an inlet end (72) and an outlet end (73) and is concentric with an axis of rotation (5) to form an inner annular layer (74), washing liquid simultaneously being introduced into the treatment channel form an outer layer (75), which surrounds the inner annular layer. The fibre suspension and washing liquid are caused to rotate in the treatment channel whilst moving from said inlet end to said outlet end, fibres in the fibre suspension being caused to move into the outer layer of washing liquid, under the influence of the centripetal force, so that an accept (29), the liquid phase of which completely or mostly consists of washing liquid, is discharged at the outlet end of the treatment channel.
    Type: Grant
    Filed: October 23, 2001
    Date of Patent: September 20, 2005
    Assignee: Kvaerner Pulping AB
    Inventors: Rolf Ekholm, Peter Wigarthsson
  • Patent number: 6896810
    Abstract: Systems and methods by which to subject cellulosic fibers to alkaline treatment are provided. The systems and methods of the invention include equipment, such as nanofiltration units and slurry concentrators, which result in a lowered overall consumption of alkaline solution during alkaline treatment. The systems and methods of the invention further allow the components of hemicaustic streams produced by such alkaline treatments to be utilized in higher value end uses.
    Type: Grant
    Filed: August 2, 2002
    Date of Patent: May 24, 2005
    Assignee: Rayonier Products and Financial Services Company
    Inventors: Omar F. Ali, John T. Cenicola, Jian Li, Jay D. Taylor
  • Patent number: 6868973
    Abstract: The present invention provides a drum type refining or washing apparatus in which the refining or washing efficiency of a pulp suspension or a food suspension is remarkably enhanced by the filtration function of a rotary drum and by the filtrate sucking force of a filtrate receptive cell.
    Type: Grant
    Filed: April 13, 2004
    Date of Patent: March 22, 2005
    Assignee: Sakae Kohki Co., Ltd.
    Inventors: Eiichi Kamo, Nobuyuki Kamo
  • Publication number: 20040244926
    Abstract: A method and system for determining trace oversize contaminant particles in a paper-making pulp employs a screen assembly having a screen housing with a screen mounted therein, and ports for introduction of aqueous pulp and rinsing and flushing fluids, and for withdrawal of screened aqueous pulp, the screen housing has no port designated for the sole purpose of removing accumulated contaminant particles from the screen housing; instead the port employed for introduction. of aqueous pulp and which may also be employed for introduction of rinsing fluid to the housing, is employed as the flushing port for removal of contaminant particles.
    Type: Application
    Filed: June 1, 2004
    Publication date: December 9, 2004
    Inventors: John David Hoffmann, James Allen Olson
  • Patent number: 6773546
    Abstract: Pulp, containing black liquor, is separated to produce pulp substantially free of black liquor. An organic solvent forms a layer within a vessel and adding a pulp containing black liquor will establish three layers. From the lower layer, pulp substantially free of black liquor is removed. From the upper layer, black liquor substantially free of pulp is removed, and the layer of organic solvent is retained in place within the vessel. The resulting separation, by dissimilar densities of the organic solvent and pulp containing black liquor produces black liquor devoid of additional dilution by water whereby pulp containing black liquor is separated to create pulp substantially free of black liquor and provides black liquor separated from the organic solvent.
    Type: Grant
    Filed: September 16, 2002
    Date of Patent: August 10, 2004
    Inventor: Gene E. Lightner
  • Publication number: 20040149404
    Abstract: The invention relates to a method of bleaching cellulose pulp in a bleach line having at least two bleaching steps D1, D2 of alkaline or acidic type, and a bleaching line for the method, in which the filtrate distribution is led up through the bleaching line in counter-current to the flow of cellulose pulp established in the bleaching line. Instead of a conventional filtrate distribution including filtrate tanks, a single joint main conduit 1 is used for the bleaching steps of the same type. Wash filtrate obtained from the wash steps of the same type used after or before the bleaching step, is led to a branch point A2, A4, A6 on the main conduit 1, that is positioned after the branch point for drawing off of wash and/or dilution liquor for the wash step in question A1, A3, A5, A7. All branch points in the joint main conduit are in open communication with each other in the main conduit, at least as seen in a direction from the last bleaching step.
    Type: Application
    Filed: January 13, 2004
    Publication date: August 5, 2004
    Inventors: Vidar Snekkenes, Lennart Gustavsson
  • Publication number: 20040134630
    Abstract: A method of adjusting a pulp washing process and measuring efficiency. The methods comprise modelling the maximum washing capacity of the washing process, selecting the variables of the washing process to be measured, measuring the variables of the washing process, and adjusting the washing process or determining the efficiency of the washing process by means of the modelling and the measurements.
    Type: Application
    Filed: December 8, 2003
    Publication date: July 15, 2004
    Inventors: Juri Lahtinen, Mikko Ulvinen
  • Publication number: 20040118529
    Abstract: The present invention aims firstly to provide a novel technique capable of preparing bleached pulp having high brightness from materials having low bleachability containing high levels of extractives and secondly to provide a technique capable of reducing the amount of bleaching agents used in processes for preparing bleached mechanical pulps.
    Type: Application
    Filed: December 9, 2003
    Publication date: June 24, 2004
    Inventors: Yasuyuki Kamijo, Isao Onodera, Keigo Watanabe, Takanori Miyanishi
  • Publication number: 20040108085
    Abstract: The invention relates to a method for separating hemicelluloses from a biomass containing hemicelluloses. Said method comprises the following steps: a) the hemicelluloses are extracted from the biomass containing hemicelluloses by means of treatment with a complex compound in an aqueous solution, forming a soluble hemicellulose complex, and b) the complexed hemicelluloses are separated from the biomass. The inventive method is especially suitable for producing high-quality chemical conversion pulp from raw cellulose. Not only does the inventive method enable the obtained products to have a high degree of purity, but it is also extremely economical and causes few emissions. The inventive method is also characterised in that polymer hemicelluloses in a pure form can be obtained as by-products.
    Type: Application
    Filed: January 16, 2004
    Publication date: June 10, 2004
    Inventors: Gerhard Kettenbach, Armin Steln
  • Patent number: 6746568
    Abstract: A method in bleaching of pulp is described, in which the pulp is subjected to a peroxide bleaching step, whereupon the pulp is washed and the washing liquid from the washing is separated from the pulp in the form of a filtrate. The method is characterised in that the filtrate is treated with an aluminium compound, such as aluminium sulphate or polyaluminium sulphate, for precipitation of interfering substances, such as oxygen-demanding organic material and metals, that the precipitated material is removed from the filtrate, that the aluminium content of the filtrate after precipitation of interfering substances is adjusted to at most 20 ppm, and that the filtrate is then recirculated to the peroxide bleaching step. By the method, a reduced consumption of hydrogen peroxide in the peroxide bleaching step is achieved.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: June 8, 2004
    Assignee: Kemira Kemi AB
    Inventors: Hans Terelius, Anette Olsson, Margareta Nilsson, Jessica Svensson, Christos Rampotas
  • Publication number: 20040099386
    Abstract: Separation of dissolved and colloidal high molecular weight organic by-products from liquors or filtrates in a cellulosic pulping process to improve the overall efficiency of the process.
    Type: Application
    Filed: November 20, 2003
    Publication date: May 27, 2004
    Inventor: Craig A. Bianchini
  • Patent number: 6736934
    Abstract: The present invention relates to a method of pretreating, by acidification and chelation, of pulp to be bleached with peroxide. Especially, the invention relates to intensifying, and at the same time simplifying the pretreatment required by peroxide bleaching. It is characteristic of the invention to introduce pulp into an acid tower (14, 112) where the pressure is 0 to 20 bar, preferably 1 to 10 bar, and the temperature 75 to 130° C. preferably 80 to 110° C., to treat the pulp in acid tower (14, 112) at a pH of 2 to 6, preferably 3 to 4, for 20 to 240 minutes, for decreasing the kappa number by 1-9, preferably 2-6 kappa units, to transfer the pulp from acid tower (14, 112) to a tower (24) of a second treatment stage, to treat the pulp with either a complexing agent at a pH of 4 to 9, preferably 5 to 6, or with an oxidizing chemical such as chlorine dioxide, Caro's acid, peracids or equivalent, and to wash and/or press the pulp.
    Type: Grant
    Filed: July 28, 1997
    Date of Patent: May 18, 2004
    Assignee: Andritz Oy
    Inventors: Kaj Henricson, Olavi Pikka
  • Patent number: 6733625
    Abstract: The present invention relates to a method of treating chemical pulp in order to optimize the consumption of bleaching chemicals and to improve the quality of the pulp. Especially the invention relates to a method according to which filtrate obtained from a suitable stage of the washing of brown stock preferably cooked by an alkaline cooking method is treated with an oxidizing chemical prior to the oxygen stage following the brown stock washing.
    Type: Grant
    Filed: May 15, 2001
    Date of Patent: May 11, 2004
    Assignee: Andritz Oy
    Inventors: Kaj Henricson, Eero Kontturi, Olavi Pikka, Janne Vehmaa
  • Publication number: 20040079498
    Abstract: This invention refers to a method for producing pulp in an alkaline digesting process comprising the following steps: charging lignocellulosic material to a digester system; pre-treating said lignocellulosic material with an impregnation liquor and subsequently with a hotter liquor containing black liquor, simultaneously displacing spent liquor; heating and cooking said lignocellulosic material to produce cooked lignocellulosic material and cooking liquor; displacing a portion of said cooking liquor at cooking temperature from said digester to a first section by supplying a washing liquid; further displacing a second portion of displaced liquor from said digester system to at least a second section by supplying further washing liquid until the temperature of said second portion of displaced liquor drops to a temperature of at least about the boiling point of said cooking liquor at atmospheric pressure, said second portion of displaced liquor having a dry solids content substantially lower than the initial dry
    Type: Application
    Filed: October 22, 2003
    Publication date: April 29, 2004
    Inventors: Hannu Haaslahti, Olavi Katajisto, Osmo Keitaaniemi, Mikael Svedman
  • Publication number: 20040074615
    Abstract: A process for producing microcrystalline cellulose comprised of the steps of contacting a paper grade pulp with an alkali hydrolysis agent, washing the hydrolyzed pulp and contacting the hydrolyzed pulp with an acid hydrolysis agent and washing the acid hydrolyzed product.
    Type: Application
    Filed: October 16, 2002
    Publication date: April 22, 2004
    Inventor: Xuan Truong Nguyen
  • Patent number: 6719878
    Abstract: A method for producing chemical pulp from cellulosic material by means of alkaline cooking, including cooking the material to pulp at cooking temperature in a digester, reducing the temperature at the end of the cook, substantially relieving the overpressure in the digester and then discharging the pulp from the digester by means of pumping. The method is characterized in that the pulp is cooled to essentially 85° C. to 70° C. before pumping cooked material as a fluid suspension from the digester, and that the temperature of the cooked material is maintained in the same temperature range and at a pH level being between 10 and 13, between the digester and a first delignification/bleaching stage, thus avoiding mechanical damage of cellulosic material.
    Type: Grant
    Filed: February 26, 2002
    Date of Patent: April 13, 2004
    Assignee: Metso Chemical Pulping Oy
    Inventor: Mikael Svedman
  • Publication number: 20040060673
    Abstract: An apparatus and process for solvent pulping of cellulose-containing biomass utilizes at least one steaming vessel, a plug screw feeder or compression screw device, at least one super-atmospheric impregnation vessel, a solvent delignification reactor capable of operating at a pressure of 350 psig or more, and a solvent containing line for introducing solvent-containing liquor at the plug screw feeder outlet or compression screw device outlet. The process and system can also include at least one series connected pressure diffuser and optionally a retention tube downstream of each pressure diffuser to provide sufficient retention time to substantially preclude re-deposition of lignin on the cellulose fibers of the biomass, a blow tank connected to the last of the pressure diffusers and retention tubes, and vessels for multistage alcohol washing.
    Type: Application
    Filed: December 9, 2003
    Publication date: April 1, 2004
    Applicant: ANDRITZ INC.
    Inventors: Joseph R. Phillips, Brian Greenwood, Bertil C. Stromberg, Thomas Pschorn
  • Publication number: 20040040678
    Abstract: A method for washing a fibre suspension with washing liquid, in which, in accordance with the invention, the fibre suspension is introduced into an annular treatment channel (24) that has an inlet end (72) and an outlet end (73) and is concentric with an axis of rotation (5) to form an inner annular layer (74), washing liquid simultaneously being introduced into the treatment channel to form an outer layer (75), which surrounds the inner annular layer. The fibre suspension and washing liquid are caused to rotate in the treatment channel whilst moving from said inlet end to said outlet end, fibres in the fibre suspension being caused to move into the outer layer of washing liquid, under the influence of the centripetal force, so that an accept (29), the liquid phase of which completely or mostly consists of washing liquid, is discharged at the outlet end of the treatment channel.
    Type: Application
    Filed: May 22, 2003
    Publication date: March 4, 2004
    Inventors: Rolf Ekholm, Peter Wigarthsson
  • Publication number: 20040040679
    Abstract: This invention relates to an improved process for manufacturing bleached thermomechanical aspen pulp having reduced yellow after treatment with aluminum based chemicals such as alum which are used in paper making processes. In this improved process the pulp is washed prior to, after or between the bleaching stages or a combination of the foregoing.
    Type: Application
    Filed: August 31, 2002
    Publication date: March 4, 2004
    Inventors: Robin R. Kilgannon, Robert J. Kane, Eileen M. Joy, Anil K. Dewan
  • Publication number: 20040020854
    Abstract: Systems and methods by which to subject cellulosic fibers to alkaline treatment are provided. The systems and methods of the invention include equipment, such as nanofiltration units and slurry concentrators, which result in a lowered overall consumption of alkaline solution during alkaline treatment. The systems and methods of the invention further allow the components of hemicaustic streams produced by such alkaline treatments to be utilized in higher value end uses.
    Type: Application
    Filed: August 2, 2002
    Publication date: February 5, 2004
    Applicant: Rayonier, Inc.
    Inventors: Omar F. Ali, John T. Cenicola, Jian Li, Jay D. Taylor
  • Publication number: 20030217822
    Abstract: A pressure diffuser is disclosed having a pressurized vessel having an inlet adapted to receive a slurry of cellulosic fibrous material and cooking liquor; an outer chamber having an assembly of screens, wherein the slurry flows through the outer chamber and a portion of the cooking liquor is extracted through the screens; a center chamber to receive cooking liquor extracted through the screens; an inner head capping the center chamber, wherein the inner head is impervious to gases escaping from the cooking liquor and collecting underneath the inner head, and a gas exhaust conduit extending from the inner head to an outlet external of the pressure diffuser, wherein the conduit has an inlet below the inner head.
    Type: Application
    Filed: January 31, 2003
    Publication date: November 27, 2003
    Inventors: John Weston, Jouni Korhonen, Pasi Heinamaki
  • Publication number: 20030213572
    Abstract: A pulp product that has a low COD is comprised of an unbleached pulp that is soaked and washed in alkaline water for a sufficient time so that the COD after soaking and washing is less than or equal to 3.0 kg/1000 kg of dry pulp. The pulp is produced by repetitively soaking and washing an unbleached pulp in alkaline water that is never allowed to drop below pH 7.0. The pulp is soaked and washed for a total of at least 400 minutes at an elevated temperature to produce the pulp product that has a low COD.
    Type: Application
    Filed: July 30, 2002
    Publication date: November 20, 2003
    Inventors: Michael D. Vrbanac, Brian Wester, Brian E. Dennis, Peter K. Lau, Julie A. Reimer, David W. Bickell
  • Publication number: 20030213570
    Abstract: A pulp product that has a low COD is comprised of an unbleached pulp that is soaked and washed in alkaline water for a sufficient time so that the COD after soaking and washing is less than or equal to 3.0 kg/1000 kg of dry pulp. The pulp is produced by repetitively soaking and washing an unbleached pulp in alkaline water that is never allowed to drop below pH 7.0. The pulp is soaked and washed for a total of at least 400 minutes at an elevated temperature to produce the pulp product that has a low COD.
    Type: Application
    Filed: July 30, 2002
    Publication date: November 20, 2003
    Inventors: Michael D. Vrbanac, Brian Wester, Brian E. Dennis, Peter K. Lau, Julie A. Reimer, David W. Bickell
  • Publication number: 20030213568
    Abstract: A process for making a pulp product that has a low COD is comprised of soaking and washing pulp in alkaline water for a sufficient time so that the COD after soaking and washing is less than or equal to 2.0 kg/1000 kg of dry pulp. The process includes repetitively soaking and washing an unbleached pulp in alkaline water that is never allowed to drop below pH 7.0. In this process, the pulp is soaked and washed for a total of at least 220 minutes at an elevated temperature to produce the pulp product that has a low COD.
    Type: Application
    Filed: December 26, 2002
    Publication date: November 20, 2003
    Inventors: Brian Wester, Michael D. Vrbanac, Julie A. Reimer, Peter K. Lau, Brian E. Dennis, David W. Bickell
  • Publication number: 20030213569
    Abstract: A pulp product that has a low COD is comprised of an unbleached pulp that is soaked and washed in alkaline water for a sufficient time so that the COD after soaking and washing is less than or equal to 2.0 kg/1000 kg of dry pulp. The pulp is produced by repetitively soaking and washing an unbleached pulp in alkaline water that is never allowed to drop below pH 7.0. The pulp is soaked and washed for a total of at least 220 minutes at an elevated temperature to produce the pulp product that has a low COD.
    Type: Application
    Filed: December 26, 2002
    Publication date: November 20, 2003
    Inventors: Brian Wester, Michael D. Vrbanac, Julie A. Reimer, Peter K. Lau, Brian E. Dennis, David W. Bickell
  • Publication number: 20030205343
    Abstract: A continuous pulp digester having an elongate horizontally aligned pressure vessel through which the wood chips and digesting fluid flow in a forward direction. In a first and second embodiments within the pressure vessel there is an inner container defining an elongate chamber or passageway having a square cross sectional configuration. In a third embodiment the digesting chamber is cylindrical. At locations along the digester, there are several pair of liquid flow inlets and liquid flow outlets which enable filtrate from a pulp washer and a digesting agent to be moved into and across the digesting chamber to flow out the flow outlets. These are recirculated in a net upstream flow pattern toward the outlet end of the digester, and discharged as black liquor at different locations in the digester.
    Type: Application
    Filed: April 18, 2003
    Publication date: November 6, 2003
    Inventor: Reijo K. Salminen
  • Patent number: 6620292
    Abstract: A multi-function process is described for the separation of cellulose fibers from the other constituents of lignocellulosic biomass such as found in trees, grasses, agricultural waste, and waste paper with application in the preparation of feedstocks for use in the manufacture of paper, plastics, ethanol, and other chemicals. This process minimizes waste disposal problems since it uses only steam, water, and oxygen at elevated temperature in the range of 180° C. to 240° C. for 1 to 10 minutes plus a small amount of chemical reagents to maintain pH in the range 8 to 13. An energy recuperation function is important to the economic viability of the process.
    Type: Grant
    Filed: February 20, 2002
    Date of Patent: September 16, 2003
    Assignee: Purevision Technology, Inc.
    Inventor: Richard C. Wingerson
  • Publication number: 20030168190
    Abstract: The invention relates to a process for the bleaching of an aqueous lignocellulosic pulp under acidic conditions in the bleaching plant of a pulp mill. The bleached pulp is used for the production of paper or pulp. The selectivity of the bleaching agent towards primary reactions with lignin is enhanced by the use of a carbon dioxide providing medium in the pulp.
    Type: Application
    Filed: March 26, 2003
    Publication date: September 11, 2003
    Inventors: Petri Juhana Jokinen, Jarmo Tapio Kahala, Hannu Sakari Sonni
  • Publication number: 20030131958
    Abstract: A treatment sequence includes ozonation under acidic conditions followed by an acidic wash for enhancing the wet strength of a cellulosic fibrous material. Preferably the ozone treatment and the acidic wash are followed by a second ozonation step under acidic conditions. The fibrous cellulosic material obtained by this treatment sequence has a breaking length of at least 100 m. The wet strength of the cellulosic fibrous material is increased without the use of additives, such as wet strength agents. This use of ozone is very simple and efficient, and leads to highly pure products. The use of ozone as the only treatment chemical in particular avoids the introduction of so-called “non-process elements” (NPE) into the treatment system, for instance metal oxides such as MgO, which are frequently used in the oxidative treatment of pulps.
    Type: Application
    Filed: November 27, 2002
    Publication date: July 17, 2003
    Inventor: Thomas Jaschinski
  • Publication number: 20030116289
    Abstract: The present invention comprises an improved method for refining cellulose that produces a highly refined cellulosic material. The method comprises soaking raw material in a mild NaOH using reduced temperatures and pressures, and refining the material with a plate refiner so that a waste water stream is reduced in volume and has a pH within a range of 8 to 9. The present invention also comprises a HRC gel having a lignin concentration of at least about one (1)% by weight, and a water retention capacity of about 25 to at least about 56 g H2O/g dry HRC.
    Type: Application
    Filed: November 25, 2002
    Publication date: June 26, 2003
    Applicant: Regents of the University of Minnesota
    Inventors: Brock Lundberg, Lin Gu, Rongsheng Roger Ruan, Ling Chen, Paul Bradley Addis, Jack Edgar Johnson
  • Patent number: 6558557
    Abstract: Process and decker for bringing together a first aqueous pulp suspension layer with at least one additional suspension layer. The process includes moving the first pulp suspension layer and the at least one additional suspension layer on moving layer supports, and guiding sides of the first pulp suspension layer and the at least one additional suspension layer that are adapted to contact each other on guiding surfaces that are one of stationary and limitedly moving. The guide surfaces include contoured surfaces arranged to run substantially parallel to the layer supports. The process further includes applying the at least one additional suspension layer onto the first pulp suspension layer at a wedge-shaped gap, and draining the first pulp suspension layer and the at least one additional suspension layer. The decker includes at least one rotating cylinder, and an endless wire guided around at least a portion of an outer circumference of the at least one rotating cylinder.
    Type: Grant
    Filed: February 16, 1999
    Date of Patent: May 6, 2003
    Assignee: Voith Sulzer Papiertechnik Patent GmbH
    Inventors: Axel Gommel, Josef Schneid, Rolf Wenske
  • Patent number: 6553593
    Abstract: The problems of non-uniform treatment of paper pulp that may be caused by differential flow velocities within a vessel, channeling, and/or disruption of the pulp flow, are substantially eliminated by providing a non-circular cross-section substantially atmospheric pressure vessel with at least one screen surface, and typically a liquid introducing device. The vessel, screen surface, and liquid introducing device are constructed and positioned with respect to each other so that during the treatment of a pulp slurry the slurry has substantially uniform width in a treatment zone, and there is substantially uniform resistance to the flow of slurry over the screen surface over any particular cross-section of the vessel in the treatment zone, and its consistency varies less than 6% in the treatment zone (e.g. between 8-14%).
    Type: Grant
    Filed: June 13, 2001
    Date of Patent: April 29, 2003
    Inventor: James R. Prough
  • Patent number: 6533896
    Abstract: A method for preparing pulp from lignin-containing cellulosic material is disclosed, including a step for acid cleaning of the lignocellulosic material, followed by alkaline delignification. The acidic step removes undesired components such as metal ions and side groups of polysaccharides, which may have adverse effects on the process especially when extensive recycling of liquors is employed within the plant.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: March 18, 2003
    Assignee: Metso Chemical Pulping Oy
    Inventors: Panu Tikka, Mikael Svedman, Thomas Fant
  • Patent number: 6514380
    Abstract: Chemical pulp is produced by cooking comminuted cellulosic fibrous material (e.g. wood chips) in a continuous digester or batch digesters or produce brown stock, and washing the brown stock in a brown stock washer to produce chemical pulp, oxygen delignifying the chemical pulp at medium consistency, and then screening the oxygen delignified pulp to produce an accept fraction and a shive-containing reject fraction. Drawbacks inherent in the prior art are overcome by directly transporting (i.e. without refining or accessory oxygen delignification) the shive-containing rejects fraction to the main fiber line before oxygen delignification (e.g. to just before a mixer for the oxygen delignification stage, to between the brown stock washer and mixer, to a coarse screen between the digester and the brown stock washer, and/or to a washer for the coarse rejects from the coarse screen).
    Type: Grant
    Filed: March 26, 1998
    Date of Patent: February 4, 2003
    Assignee: Andritz Oy
    Inventors: Antero Laine, Olavi Pikka
  • Publication number: 20030019593
    Abstract: Separation of dissolved and colloidal high molecular weight organic by-products from liquors or filtrates in a cellulosic pulping process to improve the overall efficiency of the process.
    Type: Application
    Filed: July 27, 2001
    Publication date: January 30, 2003
    Inventor: Craig A. Bianchini
  • Patent number: 6502434
    Abstract: A washer for washing a fiber suspension includes a porous surface traveling in a running direction and having a width in a direction transverse to the running direction. The porous surface is configured for carrying the fiber suspension thereon. A shower includes a pipe extending parallel to the width of the porous surface. The pipe has a sidewall with a longitudinally extending slot therein. The shower further includes a pair of lips connected to the pipe. The lips are positioned immediately adjacent to and on opposite sides of the slot, thereby defining a slot nozzle with a discharge gap. The lips are movable toward and away from each other to adjust the size of the discharge gap.
    Type: Grant
    Filed: October 16, 2000
    Date of Patent: January 7, 2003
    Assignee: Voith Sulzer Paper Technology North America, Inc.
    Inventor: Klaus Doelle
  • Publication number: 20030000661
    Abstract: Processes and systems for the treatment of wood chips prior to cooking remove substantially (e.g., at least about 30%) water-soluble compounds therein, especially those compounds which disassociate in water to form potassium and/or chloride ions and/or water-soluble metal compounds such as manganese, calcium and potassium. In preferred embodiments, wood chips entering the cooking system containing water-soluble compounds, such as those compounds which disassociate in water to form potassium and/or chloride ions and/or water-soluble metal compounds such as manganese, calcium and potassium, may be treated prior to cooking by being brought into contact with an aqueous treatment stream (e.g., water or steam condensate) at a temperature (e.g., between about 20° C. to about 120° C.) and for a time (e.g., between about 2 to 200 minutes) so as to reduce substantially (e.g., at least about 30%) such water-soluble compounds.
    Type: Application
    Filed: June 3, 2002
    Publication date: January 2, 2003
    Inventors: Kaj O. Henricson, Bertil C. Stromberg
  • Publication number: 20020148575
    Abstract: A multi-function process is described for the separation of cellulose fibers from the other constituents of lignocellulosic biomass such as found in trees, grasses, agricultural waste, and waste paper with application in the preparation of feedstocks for use in the manufacture of paper, plastics, ethanol, and other chemicals. This process minimizes waste disposal problems since it uses only steam, water, and oxygen at elevated temperature in the range of 180° C. to 240° C. for 1 to 10 minutes plus a small amount of chemical reagents to maintain pH in the range 8 to 13. An energy recuperation function is important to the economic viability of the process.
    Type: Application
    Filed: February 20, 2002
    Publication date: October 17, 2002
    Inventor: Richard C. Wingerson
  • Patent number: 6461473
    Abstract: A process for washing pulp including a dilution step, an extraction step and a subsequent displacement step. The process further includes the steps of: diluting the pulp; passing the diluted pulp to the extraction step; developing a first filtrate from the extraction step; passing the pulp from the extraction step to the displacement step; developing a second filtrate from the displacement step; segregating the first and second filtrates; providing the second filtrate to the dilution step; providing a determined minimum volume of the first filtrate needed for the dilution step; and eliminating the remaining volume of the first filtrate from further use in the washing of the pulp.
    Type: Grant
    Filed: September 23, 1998
    Date of Patent: October 8, 2002
    Assignees: Andritz Oy, GL&V Management Hungary Kft
    Inventors: Harri Qvintus, Pekka Tervola
  • Publication number: 20020139498
    Abstract: The present invention relates to a new method for producing microcrystalline cellulose using never-dried pulp as the cellulose source.
    Type: Application
    Filed: January 3, 2002
    Publication date: October 3, 2002
    Inventors: Jim Matheson, Jian Xin Guo, Sheila Murphy, Linnea Shaver
  • Publication number: 20020124977
    Abstract: The distributor device is for cellulose pulp of low and medium consistency and is used to form a uniform pulp web running from the distributor device in an apparatus treating the cellulose pulp. The distributor device has a cylindrical distributor housing arranged horizontally and transverse to the pulp web, and an inlet for the cellulose pulp at one end of the distributor housing and on the pulp web side. Pulp is fed with feed screws from the inlet and along the length of the distributor housing. The web is initially formed via the outlets defined along a generatrix in the jacket surface of the distributor housing. An optimum distribution of low-concentration pulp is obtained with the holes arranged along the generatrix in the jacket surface of the distributor housing. The holes have a defined hole diameter (D) and are arranged at a distance (X) from each other. The interaction with the feed screw makes it possible to keep the holes free from clogging.
    Type: Application
    Filed: November 6, 2001
    Publication date: September 12, 2002
    Applicant: Kvaerner Pulping AB;
    Inventors: Goran Brottgardh, Axel Lamas, Bo Clarstrom