Patents by Inventor Olavi Pikka

Olavi Pikka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8815053
    Abstract: A method of treating and utilizing liquid flows at a chemical pulp mill including stages for: a) chemical pulp is produced in an alkaline cooking process, b) the brown stock generated in the cooking is treated, said treatment comprising washing of the stock and preferably oxygen delignification and subsequent washing of the stock, c) a bleaching process for the brown stock, the bleaching sequence comprising at least one stage using chlorine dioxide and additionally at least one oxidizing bleaching stage and having at least two washing stages for treating the stock with liquids and for producing filtrates, and d) filtrates from stage c) are purified at an effluent treatment plant of the chemical pulp mill, which comprises at least biological treatment, for obtaining purified effluent. The method further includes a stage e), where the purified effluent with a color of 200 mg/l (Pt color) or more and a COD value of over 150 mg/l is used as pulp treatment liquid in stage c).
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: August 26, 2014
    Assignee: Adritz Oy
    Inventors: Janne Vehmaa, Olavi Pikka, Pekka Tervola
  • Patent number: 8632655
    Abstract: A method in connection with washing of pulp at a chemical pulp mill including at least an alkaline cooking process utilizing cooking liquor for producing pulp, brown stock treatment with essentially closed liquid cycles, in which the last washing device is a washing device based on pressing of pulp, a press or a washing press, a pulp bleaching plant using ECF-bleaching, wherein chloride-containing effluents are formed, a chemical recovery plant and effluent purification. The liquid flows generated at a chemical pulp mill are efficiently circulated without disturbing the main process and minimizing the emissions from the mill. Purified effluent in the amount of at least 1 m3/adt pulp is introduced into the dilution after the press or washing press, whereby the effluent is passed from the dilution into the first process stage of the bleaching.
    Type: Grant
    Filed: June 12, 2008
    Date of Patent: January 21, 2014
    Assignee: Andritz Oy
    Inventors: Janne Vehmaa, Olavi Pikka, Pekka Tervola
  • Patent number: 8632657
    Abstract: A method for treating liquid flows at a chemical pulp mill including at least an alkaline cooking process for producing pulp, treatment of brown stock generated in the cooking, a bleaching plant using ECF-bleaching, in which chloride-containing effluents are formed, an effluent purification plant for treating bleaching plant effluents and other effluents generated at the mill. At least a portion of the effluents is returned after the purification to the pulp production line as source of process water. More than one treatment line is arranged at the effluent purification plant for the mill effluents and effluents with different chemical compositions are purified in separate treatment lines so that the quality and amount of purified water from each treatment line is suitable for use in a stage or stages of the production process, whereto purified effluent is returned.
    Type: Grant
    Filed: June 12, 2008
    Date of Patent: January 21, 2014
    Assignee: Andritz Oy
    Inventors: Janne Vehmaa, Olavi Pikka, Pekka Tervola
  • Patent number: 8632656
    Abstract: A method for treating liquid flows at a chemical pulp mill including at least an alkaline cooking process for producing pulp, brown stock treatment with essentially closed liquid cycles, a pulp bleaching plant using ECF-bleaching, a chemical recovery plant comprising a chemical recovery boiler, and effluent purification. Chloride-containing bleaching plant effluents are led to the effluent purification, where they are treated in order to decrease the organic matter content thereof. At least 20% of the purified effluent is returned to a pulp mill process and purified effluent is used in a last washing stage included in brown stock treatment. In the brown stock treatment the liquid flow is passed counter-currently to evaporation, wherefrom it is led for treatment to a recovery boiler process, wherein a separation process for chlorides is arranged for controlling the chloride level of the liquor cycle.
    Type: Grant
    Filed: June 13, 2008
    Date of Patent: January 21, 2014
    Assignee: Andritz Oy
    Inventors: Janne Vehmaa, Olavi Pikka, Pekka Tervola
  • Publication number: 20120279669
    Abstract: A method of treating and utilizing liquid flows at a chemical pulp mill including stages for: a) chemical pulp is produced in an alkaline cooking process, b) the brown stock generated in the cooking is treated, said treatment comprising washing of the stock and preferably oxygen delignification and subsequent washing of the stock, c) a bleaching process for the brown stock, the bleaching sequence comprising at least one stage using chlorine dioxide and additionally at least one oxidizing bleaching stage and having at least two washing stages for treating the stock with liquids and for producing filtrates, and d) filtrates from stage c) are purified at an effluent treatment plant of the chemical pulp mill, which comprises at least biological treatment, for obtaining purified effluent. The method further includes a stage e), where the purified effluent with a color of 200 mg/l (Pt color) or more and a COD value of over 150 mg/l is used as pulp treatment liquid in stage c).
    Type: Application
    Filed: November 22, 2010
    Publication date: November 8, 2012
    Applicant: ANDRITZ OY
    Inventors: Janne Vehmaa, Olavi Pikka, Pekka Tervola
  • Patent number: 8277608
    Abstract: A method of treating pulp in connection with the bleaching of chemical pulp, said method including treating of the pulp in at least an ozone, chlorine dioxide or alkali phase and thereafter washing of the pulp in a washing device having an E10 value of at least 3, whereby washing liquid is introduced into the washing device countercurrently in relation to the pulp and filtrate is discharged from the washing device. At first the pulp is washed in the washing device so that the washing liquid is filtrate obtained from the washing device itself and the amount of thus circulated washing liquid is 1.5 - 3.5 t/adt pulp, whereafter the pulp is washed with liquid introduced from outside the washing device, the amount of said liquid being such that the dilution factor in the latter wash is less than 1 t/adt and that the total amount of washing liquid used in the washing device is such that the dilution factor is more than 0 t/adt.
    Type: Grant
    Filed: June 17, 2004
    Date of Patent: October 2, 2012
    Assignee: Andritz Oy
    Inventors: Kaj Henricson, Olavi Pikka, Pekka Tervola
  • Patent number: 8052839
    Abstract: An apparatus for treating pulp including: at least one liquid-permeable surface rotating around a shaft, onto which surface a pulp layer is formed; a feeder to feed pulp to the apparatus for treatment on the liquid-permeable surface; an internal barrier defining a first pulp treatment section and a second pulp treatment section; the first treatment section receiving from the feeder a first type of pulp and the second treatment section receiving from the feeder a second type of pulp, wherein the first type of pulp is supplied to the feeder from a first pulp treatment stage in a pulping system and the second type of pulp is supplied to the feeder from a second pulp treatment stage in the pulping system, and a pulp discharge to discharge treated pulp from the apparatus, wherein the pulp discharge discharges the first type of pulp after treatment separately from discharging the second type of pulp after treatment, and a filtrate discharge to discharge filtrate flowing through the liquid-permeable from the apparat
    Type: Grant
    Filed: September 7, 2005
    Date of Patent: November 8, 2011
    Assignee: Andritz Oy
    Inventors: Olavi Pikka, Pekka Tervola, Hannu Rönkönharju
  • Publication number: 20100243184
    Abstract: A method for treating liquid flows at a chemical pulp mill including at least an alkaline cooking process for producing pulp, brown stock treatment with essentially closed liquid cycles, a pulp bleaching plant using ECF-bleaching, a chemical recovery plant comprising a chemical recovery boiler, and effluent purification. Chloride-containing bleaching plant effluents are led to the effluent purification, where they are treated in order to decrease the organic matter content thereof. At least 20% of the purified effluent is returned to a pulp mill process and purified effluent is used in a last washing stage included in brown stock treatment. In the brown stock treatment the liquid flow is passed counter-currently to evaporation, wherefrom it is led for treatment to a recovery boiler process, wherein a separation process for chlorides is arranged for controlling the chloride level of the liquor cycle.
    Type: Application
    Filed: June 13, 2008
    Publication date: September 30, 2010
    Applicant: ANDRITZ OY
    Inventors: Janne Vehmaa, Olavi Pikka, Pekka Tervola
  • Publication number: 20100243183
    Abstract: A method in connection with washing of pulp at a chemical pulp mill including at least an alkaline cooking process utilizing cooking liquor for producing pulp, brown stock treatment with essentially closed liquid cycles, in which the last washing device is a washing device based on pressing of pulp, a press or a washing press, a pulp bleaching plant using ECF-bleaching, wherein chloride-containing effluents are formed, a chemical recovery plant and effluent purification. The liquid flows generated at a chemical pulp mill are efficiently circulated without disturbing the main process and minimizing the emissions from the mill. Purified effluent in the amount of at least 1 m3/adt pulp is introduced into the dilution after the press or washing press, whereby the effluent is passed from the dilution into the first process stage of the bleaching.
    Type: Application
    Filed: June 12, 2008
    Publication date: September 30, 2010
    Applicant: ANDRITZ OY
    Inventors: Janne Vehmaa, Olavi Pikka, Pekka Tervola
  • Publication number: 20100224334
    Abstract: A method for treating liquid flows at a chemical pulp mill including at least an alkaline cooking process for producing pulp, treatment of brown stock generated in the cooking, a bleaching plant using ECF-bleaching, in which chloride-containing effluents are formed, an effluent purification plant for treating bleaching plant effluents and other effluents generated at the mill. At least a portion of the effluents is returned after the purification to the pulp production line as source of process water. More than one treatment line is arranged at the effluent purification plant for the mill effluents and effluents with different chemical compositions are purified in separate treatment lines so that the quality and amount of purified water from each treatment line is suitable for use in a stage or stages of the production process, whereto purified effluent is returned.
    Type: Application
    Filed: June 12, 2008
    Publication date: September 9, 2010
    Applicant: ANDRITZ OY
    Inventors: Janne Vehmaa, Olavi Pikka, Pekka Tervola
  • Publication number: 20080196848
    Abstract: An apparatus for treating pulp including: at least one liquid-permeable surface rotating around a shaft, onto which surface a pulp layer is formed; a feeder to feed pulp to the apparatus for treatment on the liquid-permeable surface; an internal barrier defining a first pulp treatment section and a second pulp treatment section; the first treatment section receiving from the feeder a first type of pulp and the second treatment section receiving from the feeder a second type of pulp, wherein the first type of pulp is supplied to the feeder from a first pulp treatment stage in a pulping system and the second type of pulp is supplied to the feeder from a second pulp treatment stage in the pulping system, and a pulp discharge to discharge treated pulp from the apparatus, wherein the pulp discharge discharges the first type of pulp after treatment separately from discharging the second type of pulp after treatment, and a filtrate discharge to discharge filtrate flowing through the liquid-permeable from the apparat
    Type: Application
    Filed: September 7, 2005
    Publication date: August 21, 2008
    Applicant: ANDRITZ OY
    Inventors: Olavi Pikka, Pekka Tervola, Hannu Ronkonharju
  • Publication number: 20070295462
    Abstract: A method of treating pulp in connection with the bleaching of chemical pulp, said method including treating of the pulp in at least an ozone, chlorine dioxide or alkali phase and thereafter washing of the pulp in a washing device having an E10 value of at least 3, whereby washing liquid is introduced into the washing device countercurrently in relation to the pulp and filtrate is discharged from the washing device. At first the pulp is washed in the washing device so that the washing liquid is filtrate obtained from the washing device itself and the amount of thus circulated washing liquid is 1.5-3.5 t/adt pulp, whereafter the pulp is washed with liquid introduced from outside the washing device, the amount of said liquid being such that the dilution factor in the latter wash is less than 1 t/adt and that the total amount of washing liquid used in the washing device is such that the dilution factor is more than 0 t/adt.
    Type: Application
    Filed: June 17, 2004
    Publication date: December 27, 2007
    Applicant: ANDRITZ OY
    Inventors: Kaj Henricson, Olavi Pikka, Pekka Tervola
  • Patent number: 7229527
    Abstract: The present invention relates to the thickening of pulp suspensions. A low consistency pulp suspension is fed to a pre-thickener (10) through an inlet conduit (18). A layer of thickened pulp, formed on a filter surface (22), is pushed along the filter surface by a cleaning member to the discharge end of the pre-thickener and is discharged through the outlet (20). The cleaning member comprises a rotating shaft (30), on which shaft at least one screw thread (32) is fixed so as to leave a free space between the shaft and the screw thread. Essentially non-thickened pulp is allowed to flow through the apparatus via this space.
    Type: Grant
    Filed: October 22, 2003
    Date of Patent: June 12, 2007
    Assignee: Andritz-Ahlstrom Oy
    Inventors: Antero Laine, Risto Ljokkoi, Olavi Pikka, Sami Siik, Harri Qvintus
  • Publication number: 20060201642
    Abstract: A single pulp bleaching stage comprises an acid treatment, A, a neutralization treatment, n, and a chlorine dioxide treatment, D0. The AnD0 bleaching stage may optionally include washing between treatments, either between each treatment or only some treatments, represented by A-n-D0 which indicates there is washing between the acid (A) and the neutralization (n) treatments and the neutralization (n) and the chlorine dioxide (D) treatments, or An-D0 which indicates there is washing only between the neutralization (n) and the chlorine dioxide (D) treatments. The AnD0 stage can be followed by washing and further bleaching stages. Preferably, the (AnD0) stage is followed by an extraction stage Eop with caustic in the presence of oxygen and a peroxide.
    Type: Application
    Filed: January 26, 2006
    Publication date: September 14, 2006
    Applicant: ANDRITZ INC.
    Inventors: Nam Shin, Pamela O'Leary, Olavi Pikka
  • Patent number: 6767432
    Abstract: The present invention relates to the thickening of pulp suspensions. A low consistency pulp suspension is fed to a pre-thickener (10) through an inlet conduit (18). A layer of thickened pulp, formed on a filter surface (22), is pushed along the filter surface by a cleaning member to the discharge end of the pre-thickener and is discharged through the outlet (20). The cleaning member comprises a rotating shaft (30) on which shaft at least one screw thread (32) is fixed so as to leave a free space between the shaft and the screw thread. Essentially non-thickened pulp is allowed to flow through the apparatus via this space.
    Type: Grant
    Filed: March 21, 2001
    Date of Patent: July 27, 2004
    Assignee: Andritz Oy
    Inventors: Antero Laine, Risto Ljokkoi, Olavi Pikka, Sami Siik, Harri Qvintus
  • 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: 20040084160
    Abstract: The present invention relates to the thickening of pulp suspensions. A low consistency pulp suspension is fed to a pre-thickener (10) through an inlet conduit (18). A layer of thickened pulp, formed on a filter surface (22), is pushed along the filter surface by a cleaning member to the discharge end of the pre-thickener and is discharged through the outlet (20). The cleaning member comprises a rotating shaft (30), on which shaft at least one screw thread (32) is fixed so as to leave a free space between the shaft and the screw thread. Essentially non-thickened pulp is allowed to flow through the apparatus via this space.
    Type: Application
    Filed: October 22, 2003
    Publication date: May 6, 2004
    Applicant: ANDRITZ OY
    Inventors: Antero Laine, Risto Ljokkoi, Olavi Pikka, Sami Silk, Harri Qvintus
  • Patent number: 6582601
    Abstract: A method and apparatus for separating soap from liquor in a filtrate tank are particularly well suited for treating soap-containing filtrates from digester houses, bleach plants, and washer rooms in the chemical pulp processing industry. A device is disposed in the filtrate tank for generating a horizontal draw between the soap collecting devices and the soap.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: June 24, 2003
    Assignee: Andritz Oy
    Inventors: Pasi Heinämäki, Hannu Rönkönharju, Janne Vehmaa, Olavi Pikka
  • 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