Patents Assigned to Andritz Oy
  • Patent number: 10676395
    Abstract: An arrangement for burning lime mud into lime in a lime kiln. The lime mud flows counter-currently to flue gases from a feed end to a firing end and the fuel used is flue gas that is produced by gasifying a fuel in the presence of combustion air in a gasifier. The combustion air for gasification is preheated with heat generated in lime mud combustion. The arrangement is provided with a conduit between the lime kiln and the gasifier for leading air from the lime kiln into the gasifier as combustion air. At least a portion of the combustion air for gasification is preheated with heat generated in the lime mud combustion so that air is led into cooling of lime obtained in the combustion and further into the kiln, from or through the firing end of which air is taken into the gasification.
    Type: Grant
    Filed: May 9, 2017
    Date of Patent: June 9, 2020
    Assignee: Andritz Oy
    Inventor: Juhani Vehmaan-Kreula
  • Patent number: 10502410
    Abstract: An arrangement in a recovery boiler having a furnace for combusting waste liquor and a flue gas duct including vertical flue gas channels, at least some of which are provided with heat recovery units for recovering heat from flue gases. The first flue gas channel downstream of the furnace is provided with a reheater and one of the following heat recovery units: an economizer or a boiler bank. The reheater and the second heat recovery unit are located one after the other in the horizontal incoming direction of the flue gas, so that in a flue gas channel the flue gas flows in a vertical direction from above downwards and heats the reheater and the second heat recovery unit simultaneously. The heat recovery elements of the reheater and the second heat recovery unit may be positioned side by side in a direction that is crosswise with respect to the horizontal incoming direction of the flue gas.
    Type: Grant
    Filed: January 25, 2017
    Date of Patent: December 10, 2019
    Assignee: Andritz Oy
    Inventor: Jukka Röppänen
  • Patent number: 10443839
    Abstract: A method and a boiler for decreasing the amount of nitrogen oxides in flue gases of a boiler, which flue gases are generated in the combustion of fuels and air. The boiler has a water circulation system comprising superheaters and a furnace for combustion of fuel and for generating flue gases that contain nitrogen oxides, which flue gases mainly flow upwards in the furnace and further to the superheater zone and via other heat recovery surfaces of the boiler out of the boiler, and a nitrogen oxides reducing agent is introduced into the flue gases. The nitrogen oxides reducing agent is introduced into the flue gases prior to the superheater zone, after the temperature of the flue gases is decreased by at least one heat exchanger that is located upstream of the nose of the boiler and upstream of the introduction of the nitrogen oxides reducing agent.
    Type: Grant
    Filed: April 8, 2016
    Date of Patent: October 15, 2019
    Assignee: ANDRITZ OY
    Inventors: Pasi Miikkulainen, Lauri Pakarinen
  • Patent number: 10391428
    Abstract: A pressure filter for treating liquor suspensions of a cellulose pulp mill, the pressure filter including a container having tubular filtering elements suspended in a horizontal plate, through which elements filtrate flows and the interior of which communicates with a filtrate chamber located above. The filtering elements collect on their outer surface precipitate that is arranged to be periodically removed by making the filtrate in the filtrate chamber travel counter-currently through the filtration surface of the filtering elements. The filtering elements are cleaned by wash liquid passing from the filtrate chamber into the filtering elements and through their filtration surface. The interior of the filtering elements is provided with a flow distributor above the middle of a filtering element for distributing the flow from the filtrate chamber onto the filtration surface of the filtering element.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: August 27, 2019
    Assignee: Andritz Oy
    Inventors: Ilkka Holopainen, Jari Paykkonen
  • Patent number: 10329713
    Abstract: The present invention relates to a method of producing steam at a digester plant of a chemical pulp mill. Black liquor is discharged from the digester at a first temperature and pressure. The black liquor is treated in a flash tank for generating flashed black liquor and flash steam at a second temperature and a second pressure, which are lower than the first temperature and pressure. The flashed black liquor is taken for further treatment to the evaporation plant. The flash steam is led to an indirect heat exchange contact with clean liquid in the reboiler for boiling the liquid and for generating steam. The steam is led from the reboiler into a fan or compressor for increasing the steam pressure to a third pressure, which is higher than the second pressure and for adjusting the pressure of the steam in the flash tank. Steam at a third pressure is used for pretreating comminuted cellulosic fiber material, such as chips, prior to cooking.
    Type: Grant
    Filed: March 4, 2015
    Date of Patent: June 25, 2019
    Assignee: ANDRITZ OY
    Inventors: Johan Engstrom, Paivi Ketonen, Peter Koistinen
  • Patent number: 10240287
    Abstract: A method and system for heating a hydraulic digester, such as a single-vessel hydraulic digester, which has a top separator, a level of chips and a liquid phase above the level of chips. The method includes: a. entraining chips in liquor to produce a slurry having a first temperature, b. feeding the slurry of chips to the digester through the top separator, c. supplying direct steam to the liquid phase between the level of chips and the top separator to heat the slurry to a second temperature for the impregnation stage, wherein the steam is fed by using at least one steam injector having a plurality of steam discharge openings; and d. heating the slurry to a third temperature and cooking the chips in a cooking zone, and withdrawing the cooked pulp from the bottom of the digester.
    Type: Grant
    Filed: September 10, 2015
    Date of Patent: March 26, 2019
    Assignee: Andritz Oy
    Inventors: Auvo Kettunen, Pasi Heinämäki, Kari Peltonen, Hannu Råmark
  • Patent number: 10179972
    Abstract: A method of utilizing lignin-containing material separated from spent kraft pulping liquor including: acidifying the liquor to a pH not less than seven thereby precipitating solid particles, separating precipitated solid particles from the accompanying liquid, and subjecting the separated precipitated solid particles to a washing process in which: the separated precipitated solid particles are washed with an aqueous medium or aqueous media in one or more washing steps, in each one of the washing steps, the aqueous washing medium contains, in a dissolved form, significant amounts of one or more added sodium salts, and a combined concentration of the added sodium salts in the washing medium in each of the washing step exceeds three percent by weight; and utilizing as fuel in a lime kiln at least part of the washed lignin-containing material is utilized as fuel in a lime kiln of a pulp mill.
    Type: Grant
    Filed: May 26, 2015
    Date of Patent: January 15, 2019
    Assignee: ANDRITZ OY
    Inventor: Paterson McKeough
  • Patent number: 10160706
    Abstract: A method for purifying raw methanol containing sulfur compounds, wherein the method comprises the step of washing raw methanol with a non-polar organic solvent.
    Type: Grant
    Filed: October 13, 2014
    Date of Patent: December 25, 2018
    Assignee: ANDRITZ OY
    Inventors: Jan Warnqvist, Johan Olsson Släger, Anders Eliasson
  • Patent number: 10132495
    Abstract: A method and a system for monitoring the mass changes of a heat exchanger bank of a steam boiler. The heat exchanger bank is supported by hanger rods and support beams to the frame beams of the steam boiler. In the method, the web plates of the support beams are provided with strain gages for measuring the changes in the strain state generated in the support beams by the mass of the heat exchanger bank. The system includes strain gages fixed to the web plates of the support beams for measuring the changes in the strain state generated in the support beam by the mass of the heat exchanger bank, data logging means for logging the measurement data and a computer or a corresponding calculation unit for processing the measurement data.
    Type: Grant
    Filed: June 10, 2014
    Date of Patent: November 20, 2018
    Assignee: ANDRITZ OY
    Inventor: Ilkka Pollanen
  • Patent number: 10011949
    Abstract: A method used in connection with the recovery of pulping chemicals from spent pulping liquor produced by kraft-type pulping at very high sulphidity. In the method, spent pulping liquor is acidified to a relatively low pH which converts a most or all of the sulphide and hydrosulphide in the liquor to hydrogen sulfide. Sulphur containing gases released from the acidification of the spent pulping liquor, together with other sulphur gases collected at the pulp mill, are converted into an acid compound. This acid compound is employed as an acidification agent in the acidification of the spent pulping liquor. The amount of acid compound generated by the conversion of sulphur containing gases may be sufficient to provide most, if not all, of the acid needed for the acidification of the spent pulping liquor.
    Type: Grant
    Filed: February 3, 2014
    Date of Patent: July 3, 2018
    Assignee: Andritz OY
    Inventor: Paterson McKeough
  • Patent number: 9901853
    Abstract: A method and an apparatus for washing a solids-containing suspension by means of a suction drum washer comprising a drum provided with a filtration surface, a main vacuum source such as a drop leg and washing tubes connected to the frame of the suction drum washer. A washing liquid stream is introduced by a first washing tube is directed to contact the pulp layer on the surface of the drum in a point below 10 degrees after the surface of the suspension and a vacuum of at least 0.1 bar greater than the main vacuum source, i.e. intensified suction is applied by means of a separate vacuum source to filtering surface at the contacting point of the first liquid stream and the pulp layer or maximum of 10 degrees before the contacting point. The intensified suction may be utilized also for boosting end of filtration stage (II) and drying stage (IV). Filtrate from the drying stage (IV) can be used at the same washer as a washing liquid at the first or the second washing tube.
    Type: Grant
    Filed: December 14, 2012
    Date of Patent: February 27, 2018
    Assignee: Andritz Oy
    Inventors: Pasi Harkonen, Simo Karjalainen, Tuomo Lintunen, Erkki Savolainen
  • Patent number: 9719209
    Abstract: A method to be used in conjunction with a single-stage or multi-stage process for leaching ash originating from the recovery boiler of a pulp mill, particularly when the ash contains a significant amount of carbonate, wherein calcium compounds, such as calcium oxide (CaO) or calcium hydroxide (Ca(OH)2), are employed as additives in one or more leaching stages, a liquid fraction formed in the leaching process is utilized outside the main chemical recovery cycle, such as a substitute for purchased sodium hydroxide in the bleaching line of the pulp mill, and a solids fraction may be mixed with a black-liquor stream of the mill or subjected to further processing to separate calcium compounds for recycle.
    Type: Grant
    Filed: November 15, 2013
    Date of Patent: August 1, 2017
    Assignee: Andritz Oy
    Inventor: Paterson McKeough
  • Patent number: 9713811
    Abstract: A bottom grate for a crusher for chipping or comminuting material which includes: support ribs each substantially perpendicular to the rotational axis of the crusher; grate blades mounted to the support ribs and substantially parallel to the rotational axis, wherein the grate blades are releasably mounted to the support ribs and the grate blades each have a cutting edge proximate to a cutting or crushing rotor in the crusher; pulling members extending between two of the support members, wherein the pulling members are in tension and the tension in the pulling members binds the blades in the support members.
    Type: Grant
    Filed: May 4, 2012
    Date of Patent: July 25, 2017
    Assignee: Andritz Oy
    Inventors: Markku Kaljunen, Pekka Kokko
  • Publication number: 20170183818
    Abstract: A method and a liquor filter, in which liquor filter sealing medium is fed via a sealing medium channel (3) into an innermost sealing zone formed by an innermost sealing member (1), an outer seal (2) and the space between them at a causticizing plant of a chemical pulp mill. The sealing medium used is an alkaline sealing liquid and/or gas, which does not substantially dilute the liquor being filtered. Advantageously the sealing medium is filtrate from the liquor filter and/or gas taken from the interior of the liquor filter.
    Type: Application
    Filed: March 26, 2015
    Publication date: June 29, 2017
    Applicant: Andritz Oy
    Inventors: Tommi HAMMARBERG, Mika KOTTILA, Matti MANTSINEN, Simo SUUTARI
  • Patent number: 9643885
    Abstract: The present invention relates to a method and an arrangement for burning lime mud into lime in a lime kiln. The lime mud flows counter-currently to flue gases from a feed end to a firing end and the fuel used is flue gas that is produced by gasifying a fuel in the presence of combustion air in a gasifier. The combustion air for gasification is preheated with heat generated in lime mud combustion. The arrangement is provided with a conduit between the lime kiln and the gasifier for leading air from the lime kiln into the gasifier as combustion air. At least a portion of the combustion air for gasification is preheated with heat generated in the lime mud combustion so that air is led into cooling of lime obtained in the combustion and further into the kiln, from or through the firing end of which air is taken into the gasification.
    Type: Grant
    Filed: February 23, 2012
    Date of Patent: May 9, 2017
    Assignee: Andritz Oy
    Inventor: Juhani Vehmaan-Kreula
  • Patent number: 9636611
    Abstract: A method associated for treating a precoat on a rotating filtering surface of lime sludge filter including: accumulating a precoat of lime sludge on the filtering surface by rotating the filtering surface in a first direction through a lime sludge slurry; after accumulating the precoat, rotating the filtering surface in an opposite direction to the first direction; while rotating the filtering surface in the opposite direction, spraying a liquid onto the precoat on the filtering surface wherein the spraying is applied to the precoat above a scraper adjacent the filtering surface and the spraying removes at least a portion of the precoat from the filtering surface, and flowing the removed precoat over the scraper and into a basin.
    Type: Grant
    Filed: February 5, 2013
    Date of Patent: May 2, 2017
    Assignee: Andritz Oy
    Inventor: Pentti Luukkanen
  • Patent number: 9573140
    Abstract: A closing valve unit for a centrifugal cleaner arrangement including first and second connecting members configured to connect a cyclone to a centrifugal cleaner group, and a movable valve sandwiched between the first and second connecting members, the moveable valve including apertures commensurate with openings to feed and reject conduits of the cyclone and to openings to feed and reject conduits of the cyclone cleaner group, wherein the movable valve has a first position in which the apertures are aligned with the cyclone and cleaner group feed conduits and with the cyclone accept and cleaner group accept conduits, and a control element connected to the moveable valve and configured to move the moveable valve between the first position and the second positions.
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: February 21, 2017
    Assignee: Andritz Oy
    Inventors: Jarmo Immonen, Marita Jarvinen, Simo Suortti
  • Patent number: 9562323
    Abstract: A recovery boiler plant of a chemical pulp mill including: a boiler including a lower region with an outlet to discharge smelt; a dissolving tank proximate to the outlet and configured to receive smelt; a smelt spout coupled to the outlet and including a chute extending from the outlet to a position at or over an inlet to the dissolving tank; and a shielding room including walls, a ceiling and a floor, wherein one of the walls includes a wall of the boiler, and the shielding room encloses a volume adjacent the boiler and above the dissolving tank, wherein the enclosed volume includes and the smelt spout and a working area in front of the smelt spout.
    Type: Grant
    Filed: May 16, 2013
    Date of Patent: February 7, 2017
    Assignee: Andritz Oy
    Inventors: Ari Heinola, Veli Riikonen
  • Publication number: 20170016180
    Abstract: The present invention relates to a method of producing steam at a digester plant of a chemical pulp mill. Black liquor is discharged from the digester at a first temperature and pressure. The black liquor is treated in a flash tank for generating flashed black liquor and flash steam at a second temperature and a second pressure, which are lower than the first temperature and pressure. The flashed black liquor is taken for further treatment to the evaporation plant. The flash steam is led to an indirect heat exchange contact with clean liquid in the reboiler for boiling the liquid and for generating steam. The steam is led from the reboiler into a fan or compressor for increasing the steam pressure to a third pressure, which is higher than the second pressure and for adjusting the pressure of the steam in the flash tank. Steam at a third pressure is used for pretreating comminuted cellulosic fiber material, such as chips, prior to cooking.
    Type: Application
    Filed: March 4, 2015
    Publication date: January 19, 2017
    Applicant: ANDRITZ OY
    Inventors: Johan ENGSTROM, Paivi KETONEN, Peter KOISTINEN
  • Patent number: 9540767
    Abstract: A method for bleaching pulp is provided. In the method at least one tertiary amine compound is introduced into a process stage of bleaching. This process stage is a stage which comprises mixing pulp and a chlorine compound capable of bleaching.
    Type: Grant
    Filed: April 3, 2013
    Date of Patent: January 10, 2017
    Assignees: KEMIRA OYJ, ANDRITZ OY, UPM-KYMMENE CORPORATION, STORA ENSO OYJ, METSÄ FIBRE OY
    Inventors: Tapani Vuorinen, Anna-Stiina Jääskeläinen, Andreas Lindberg