Patents by Inventor Monica Bokstrom
Monica Bokstrom 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).
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Patent number: 7294227Abstract: A system for treating pulp comprises a dewatering device (2) for dewatering the pulp to a fiber concentration of at least 20%, a closed pulp-shredding vessel (16) for shredding the dewatered pulp, and an outlet pipe (22) from the pulp-shredding vessel. A transport screw (18) is arranged in the outlet pipe for transporting the shredded pulp from the pulp-shredding vessel through the outlet pipe through a reactor vessel (6) for bleaching the shredded pulp through reaction with ozone gas. The outlet pipe (22) is designed with a heightened roof portion (27), so that an upper gas space (29) free from pulp is formed in the outlet pipe between the roof portion and the transport screw. A flow-restraining member in the form of a partition wall (31) is arranged in the upper gas space in the outlet pipe for restraining the gas flow through the gas space, whereby the pumping action of the transport screw in the outlet pipe is decreased.Type: GrantFiled: December 4, 2002Date of Patent: November 13, 2007Assignee: Metso Paper, Inc.Inventors: Monica Bokström, Per Åström
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Patent number: 6989078Abstract: Methods and systems for the treatment of pulp are provided. The methods include dewatering pulp to a fiber concentration of at least 20%, shredding the dewatered pulp in a closed pulp shredding vessel, transporting the shredded pulp without compression continuously out of the pulp shredding vessel through an outlet pipe which is kept completely filled with passing pulp, directly transporting the shredded pulp to a reaction vessel through a gas-tight conduit gas sealed from the surroundings and communicating with the outlet pipe and the reaction vessel, bleaching the shredded pulp in the reaction vessel with ozone gas, and regulating the gas pressure in the pulp shredding vessel and in the reaction vessel so that ozone gas is prevented from leaking upstream through the outlet pipe.Type: GrantFiled: May 24, 2000Date of Patent: January 24, 2006Assignee: Valmet Fibertech ABInventors: Monica Bokström, Per Åström
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Publication number: 20050121158Abstract: A system for treating pulp comprises a dewatering device (2) for dewatering the pulp to a fiber concentration of at least 20%, a closed pulp-shredding vessel (16) for shredding the dewatered pulp, and an outlet pipe (22) from the pulp-shredding vessel. A transport screw (18) is arranged in the outlet pipe for transporting the shredded pulp from the pulp-shredding vessel through the outlet pipe through a reactor vessel (6) for bleaching the shredded pulp through reaction with ozone gas. The outlet pipe (22) is designed with a heightened roof portion (27), so that an upper gas space (29) free from pulp is formed in the outlet pipe between the roof portion and the transport screw. A flow-restraining member in the form of a partition wall (31) is arranged in the upper gas space in the outlet pipe for restraining the gas flow through the gas space, whereby the pumping action of the transport screw in the outlet pipe is decreased.Type: ApplicationFiled: December 4, 2002Publication date: June 9, 2005Inventors: Monica Bokström, Per Astrom
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Patent number: 6458242Abstract: Processes are disclosed for bleaching pulp with ozone in an environmentally friendly bleaching plant. The processes include removing a first filtrate from the pulp, bleaching the treated pulp with ozone, washing the bleached pulp with a washing liquid to provide a washed bleached pulp and a second filtrate including oxalic acid, recycling the second filtrate to the pulp prior to the bleaching step, and transferring the first filtrate to the bleached pulp.Type: GrantFiled: March 8, 2001Date of Patent: October 1, 2002Assignee: Valmet Fibertech AktiebolagInventor: Monica Bokström
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Patent number: 6454900Abstract: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.Type: GrantFiled: June 21, 2001Date of Patent: September 24, 2002Assignee: Sunds Defibrator Industries ABInventors: Monica Bokström, Pia Mellander, Solveig Nordén
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Publication number: 20010052400Abstract: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.Type: ApplicationFiled: January 12, 2001Publication date: December 20, 2001Inventors: Monica Bokstrom, Pia Mellander, Solveig Norden
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Publication number: 20010050152Abstract: Methods for oxygen delignification of chemical pulps are disclosed including contacting the chemical pulp with oxygen first in an upstream reactor vessel and then in a downstream reactor vessel. The upstream reactor vessel is maintained at pressures of greater than about 3 bar, and the downstream reactor vessel is maintained at temperatures of between about 90 and 120° C. and corresponding predetermined pressures. Heating of the partially delignified chemical pulp between the upstream and downstream reactors is accomplished by contacting the partially delignified chemical pulp with low pressure steam.Type: ApplicationFiled: February 12, 2001Publication date: December 13, 2001Inventors: Kjell Forslund, Rune Larsson, Matts Sundin, Monica Bokstrom
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Patent number: 6319357Abstract: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.Type: GrantFiled: January 12, 2001Date of Patent: November 20, 2001Assignee: Valmet Fibertech AktiebolagInventors: Monica Bokström, Pia Mellander, Solveig Nordén
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Publication number: 20010035272Abstract: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.Type: ApplicationFiled: June 21, 2001Publication date: November 1, 2001Inventors: Monica Bokstrom, Pia Mellander, Solveig Norden
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Patent number: 6238517Abstract: Methods of controlling oxygen delignification processes are disclosed including providing chemicals for a first oxygen delignification step, conducting the first oxygen delignification step with the chemicals, conducting a second oxygen delignification step at a predetermined temperature to produce a delignified pulp, measuring the final kappa number of the delignified pulp subsequent to the second oxygen delignification step, adjusting the chemicals provided for the first oxygen delignification step based upon the difference between the actual kappa number reduction and the desired kappa number reduction for the pulp, and adjusting the predetermined temperature based on the chemicals provided to the first oxygen delignification step in order to provide the delignified pulp at a final pH of from about 10.5 to about 11.5.Type: GrantFiled: May 25, 1999Date of Patent: May 29, 2001Assignee: Valmet Fibertech AktiebolagInventors: Monica Bokström, Jan-Eric Häggqvist
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Patent number: 6221206Abstract: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.Type: GrantFiled: September 11, 1997Date of Patent: April 24, 2001Assignee: Valmet Fibertech AktiebolagInventors: Monica Bokström, Pia Mellander, Solveig Nordén
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Patent number: 6221207Abstract: Methods for oxygen delignification of chemical pulps are disclosed including contacting the chemical pulp with oxygen first in an upstream reactor vessel and then in a downstream reactor vessel. The upstream reactor vessel is maintained at pressures of greater than about 3 bar, and the downstream reactor vessel is maintained at temperatures of between about 90 and 120° C. and corresponding predetermined pressures. Heating of the partially delignified chemical pulp between the upstream and downstream reactors is accomplished by contacting the partially delignified chemical pulp with low pressure steam.Type: GrantFiled: September 22, 1998Date of Patent: April 24, 2001Assignee: Valmet Fibertech AktiebolagInventors: Kjell Forslund, Rune Larsson, Matts Sundin, Monica Bokström
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Patent number: 5997689Abstract: A method of bleaching secondary fibers. A secondary fiber pulp is first slushed and then transferred at a consistency of 20-40% to a disperser. In the disperser, the secondary fiber pulp is mechanically treated and mixed so that ink particles in the secondary fiber pulp are dispersed throughout the secondary fiber pulp. While the secondary fiber pulp is being treated and mixed in the disperser, oxygen is delivered to the disperser so as to distribute the oxygen within the secondary fiber pulp.Type: GrantFiled: July 3, 1997Date of Patent: December 7, 1999Assignee: AGA AktienbolagInventor: Monica Bokstrom
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Patent number: 5582352Abstract: A method of producing chemimechanical pulp, comprises the steps of grinding wood in a grinding mill housed in a grinding chamber, maintaining the chamber at an overpressure, spraying water onto the wood, and supplying oxygen and/or hydrogen peroxide via the spray water to the grinding chamber.Type: GrantFiled: March 7, 1995Date of Patent: December 10, 1996Assignee: AGA AktiebolagInventor: Monica Bokstrom
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Patent number: 5429717Abstract: Method in the washing of alkaline, cellulosic pulp, for example sulphate pulp, CTMP and CMP pulp, the washing being effected in at least one stage. By an addition of carbon dioxide, there will be realized greatly reduced washing losses of, primarily, inorganic ions, as well as improved washing-out of substances which give rise to chemical oxygen demand (COD).Type: GrantFiled: July 29, 1993Date of Patent: July 4, 1995Assignee: AGA AktiebolagInventors: Monica Bokstrom, Raimo Rasimus