Patents by Inventor Ake Backlund
Ake Backlund 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: 6113742Abstract: The present invention relates to a digester for continuous cooking under raised pressure and temperature of fibre material in a vertical digester (1), where input of fibre material and cooking liquid takes place at the top of the digester, withdrawal of spent cooking liquor is carried out from at least one digester screening arrangement (1D) between the top and the bottom of the digester, and fibre material is fed out from the bottom (1C) of the digester, wherein the digester (1) is fitted with an additional digester screening arrangement (2) above the lowest screening arrangement (1B) of the digester so that the temperature in all the participatory cooking zones in the digester can be kept at essentially the same temperature level.Type: GrantFiled: July 21, 1997Date of Patent: September 5, 2000Assignee: Kvaerner Pulping ABInventors: Ake Backlund, Johanna Svanberg
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Patent number: 5827401Abstract: A screen system for a digester for continuous cooking under raised pressure and temperature of fiber material in a vertical vessel, where input of fiber material and cooking liquid takes place at the top of the digester, withdrawal of spent cooking liquor is carried out from at least one digester screening arrangement (1D) between the top and the bottom of the digester, and fiber material is fed out from the bottom (1C) of the digester, wherein at least one of said screening arrangements (1, 2) has at least one screen element (2A) of which the main configuration is circular and which is assembled by means of welding, and which is fitted into the digester shell by means of welding.Type: GrantFiled: January 16, 1997Date of Patent: October 27, 1998Assignee: Kvaerner Pulping Technologies ABInventors: Ake Backlund, Kenneth Bellstrom, Finn Oulie, Johanna Svanberg, Soren Soderqvist
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Patent number: 5766413Abstract: The present invention relates to a digester for continuous cooking under raised pressure and temperature of fibre material in a vertical digester (1), where input of fibre material and cooking liquid takes place at the top of the digester, withdrawal of spent cooking liquor is carried out from at least one digester screening arrangement (1D) between the top and the bottom of the digester, and fibre material is fed out from the bottom (1C) of the digester, wherein the digester (1) is fitted with an additional digester screening arrangement (2) located at less than about 1.5 meters above the lowest screening arrangement (1B) of the digester so that the temperature in all the participatory cooking zones in the digester can be kept at essentially the same temperature level.Type: GrantFiled: August 13, 1996Date of Patent: June 16, 1998Assignee: Kvaerner Pulping ABInventors: Ake Backlund, Johanna Svanberg
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Patent number: 5628872Abstract: The process for producing hydrogen peroxide, used in the bleaching of pulp, uses the hydrogen generated wholly or partly by the gasification or partial combustion of cellulose spent liquors used in digesting cellulose material to produce the hydrogen peroxide.Type: GrantFiled: April 10, 1995Date of Patent: May 13, 1997Assignee: Kanyr ABInventors: Ake Backlund, Lars Stigsson, Ove Wallergard
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Patent number: 5591303Abstract: In a pulp digester for continuous cooking under raised pressure and temperature of fiber material in a vertical digester (1), input of fiber material and cooking liquid takes place at the top of the digester, withdrawal of spent cooking liquor is carried out from at least one digester screening arrangement (1D) between the top and the bottom of the digester, and fiber material is fed out from the bottom (1C) of the digester, and at least one screening arrangement (2) in the lower half of the digester, wherein at least one of said screening arrangements (1, 2) has at least one screen element (2A) of which the main configuration is of angular shape, preferably rectangular, most preferred square, having a screen face (3A) of which the total area is less than 1 m.sup.Type: GrantFiled: March 22, 1995Date of Patent: January 7, 1997Assignee: Kvaerner Pulping Technologies ABInventors: Finn Oulie, Ake Backlund, Johanna Svanberg
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Patent number: 5567280Abstract: A screen system for a digester for continuous cooking under raised pressure and temperature of fibre material in a vertical vessel, where input of fibre material and cooking liquid takes place at the top of the digester, withdrawal of spent cooking liquor is carried out from at least one digester screening arrangement (1D) between the top and the bottom of the digester, and fibre material is fed out from the bottom (1C) of the digester, wherein at least one of said screening arrangements (1, 2) has at least one screen element (2A) of which the main configuration is circular and which is assembled by means of welding, and which is fitted into the digester shell by means of welding.Type: GrantFiled: March 31, 1995Date of Patent: October 22, 1996Assignee: Kvaerner Pulping AktiebolagInventors: Ake Backlund, Kenneth Bellstrom, Finn Oulie, Johanna Svanberg, Soren Soderqvist
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Patent number: 5529661Abstract: A process for the continuous digestion of cellulosic fiber material, comprising impregnation with impregnating liquid consisting of at least one fresh digesting liquor, in a closed impregnating system and subsequent digestion with digesting liquid in a closed digester system, said impregnating liquid being supplied through a supply system, together with steamed fibre material, to an inlet end of the impregnating system, liquid being withdrawn from the impregnating system at a point (46) located at a predetermined distance from said inlet end.Type: GrantFiled: March 13, 1995Date of Patent: June 25, 1996Assignee: Kvaerner Pulping Technologies ABInventor: Ake Backlund
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Patent number: 5470437Abstract: In a pulp digester for continuous cooking under raised pressure and temperature of fiber material in a vertical digester (1), input of fiber material and cooking liquid takes place at the top of the digester, withdrawal of spent cooking liquor is carried out from at least one digester screening arrangement (1D) between the top and the bottom of the digester, and fiber material is fed out from the bottom (1C) of the digester, and at least one screening arrangement (2) in the lower half of the digester, wherein at least one of said screening arrangements (1, 2) has at least one screen element (2A) of which the main configuration is of angular shape, preferably rectangular, most preferred square, having a screen face (3A) of which the total area is less than 1 m.sup.Type: GrantFiled: July 16, 1993Date of Patent: November 28, 1995Assignee: Kvaerner Pulping Technologies ABInventors: Finn Oulie, Ake Backlund, Johanna Svanberg
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Patent number: 5415734Abstract: A process is disclosed for bleaching pulp without chlorine containing chemicals and for greatly reducing total washing filtrate discharge, comprising the steps of: 1) sending pulp that has been subjected to continuous digestion, oxygen-delignification and then washing, through a washing press; 2) treating, with agitation, the delignified washed pulp with sulfuric acid and a chelating agent; 3) washing the pulp in a washing apparatus; 4) bleaching with hydrogen peroxide in a reaction vessel; 5) washing the hydrogen peroxide bleached pulp; 6) adding sulfuric acid and ozone with mixing of the pulp; 7) reacting the pulp with ozone in a reaction vessel; and 8) washing the ozone reacted pulp, wherein the majority of liquid filtrate from the bleaching process that is waste not to be recycled is drawn off from the washing apparatus of step 3, the washings in step 3 and 5 have at least 85% efficiency, filtrate from washing step 5 is recirculated to the washing apparatus of step 3, and filtrate from the washing apparatType: GrantFiled: May 11, 1993Date of Patent: May 16, 1995Assignee: Kvaerner Pulping Technologies ABInventors: Ake Backlund, Stig Andtbacka, Bjorn Dillner
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Patent number: 5217575Abstract: A process for oxygen bleaching fibrous cellulose pulp is described in which the pulp passes a first delignification zone with a predetermined low temperature and a second delignification zone with a predetermined high temperature which is higher than that in the first delignification zone. The pulp is fed through a first vertical reactor containing said first delignification zone with low temperature, and thereafter through a second vertical reactor containing said second delignification zone with high temperature. The temperature in the first delignification zone is either maintained at the temperature that the pulp entering for bleaching has acquired during a previous treatment before the oxygen bleaching, or as required is adjusted by the controlled supply of steam to a mixer disposed in the pipe before the first reactor. The temperature in the second delignification zone is adjusted by the controlled supply of steam to a mixer disposed in the pipe between the two reactors.Type: GrantFiled: March 24, 1992Date of Patent: June 8, 1993Assignee: Kamyr ABInventor: Ake Backlund
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Patent number: 5192396Abstract: A process for the continuous digestion of cellulosic fiber material is described wherein the material is impregnated with liquid in a closed system comprising a concurrent flow zone and a countercurrent flow zone, the liquid in the concurrent flow zone including black liquor and possibly white liquor and the liquid in the countercurrent flow zone including white liquor. Liquid is withdrawn from the impregnation system at a point located between the concurrent flow zone and the countercurrent flow zone. Besides white liquor a predetermined amount of black liquor is added to the countercurrent flow zone in order to obtain a high liquid to wood ratio in the inlet of the digester.Type: GrantFiled: September 24, 1991Date of Patent: March 9, 1993Assignee: Kamyr ABInventor: Ake Backlund
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Patent number: 5080755Abstract: A process for the continuous digestion of cellulosic fiber material is described wherein the material is impregnated with liquid in a closed system comprising a concurrent flow zone and a countercurrent flow zone, the liquid in the concurrent flow zone including black liquor and possibly white liquor and the liquid in the countercurrent flow zone including white liquor. Liquid is withdrawn from the impregnation system at a point located between the concurrent flow zone and the countercurrent flow zone. Besides white liquor a predetermined amount of black liquor is added to the countercurrent flow zone in order to obtain a high liquid to wood ratio in the inlet of the digester.Type: GrantFiled: October 12, 1989Date of Patent: January 14, 1992Assignee: Kamyr ABInventor: Ake Backlund
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Patent number: 4968385Abstract: A method of preparing a pulp for digestion in a continuous process from a fiber-containing cellulose material is described.Type: GrantFiled: May 25, 1989Date of Patent: November 6, 1990Assignee: Kamyr ABInventors: Julio Amador, Eurico de Faria Amaro, Hans T. Haukerud, Ake Backlund
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Patent number: 4922989Abstract: Resin is removed from mechanical pulps, such as TMP, CTMP, and the like, in a quick and simple manner. Mechanical pulp at a consistency of about 7-20 percent (preferably 8-15 percent) is subjected to high turbulence. The high turbulence may be effected by fluidizing the pulp, as in a centrifugal fluidizing pump, or otherwise by subjecting it to high turbulence as in a mixer, screen, or disc mill refiner. By subjecting the pulp to high turbulence treatment for a time period of about 0.2-10 seconds, resin removal is greatly enhanced, and in subsequent dewatering of the pulp a pressate is formed which has a higher concentration of resin in the pressate than in pressates produced by conventional processes. After dewatering the pulp is preferably diluted (again to about 7-20 percent consistency), and the turbulence and dewatering steps are repeated. Chemicals to improve deresination can be added to the pulp while it is subjected to high turbulence.Type: GrantFiled: October 15, 1985Date of Patent: May 8, 1990Assignee: Kamyr ABInventors: Ake Backlund, Olof Ferritsius, Goran Tistad
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Patent number: 4596631Abstract: The latency of mechanical pulp is removed in a quick and simple manner. After refining of comminuted cellulosic material to produce mechanical pulp, the pulp is diluted (if necessary) to a consistency of between about 8-25%, and the pulp is then merely pumped to a further treatment stage. Pumping is effected utilizing a centrifugal pump which fluidizes the pulp, the fluidization imparting sufficient energy to the pulp to remove the latent properties. The pulp may be pumped to a storage stage prior to passage to a screening stage, and can be pumped in a direct (non-return) path from the pump to the screening stage. If desired or necessary, a portion of the pumped pulp can be recirculated and pumped again to ensure that sufficient energy is imparted thereto to effect latency removal.Type: GrantFiled: May 8, 1984Date of Patent: June 24, 1986Assignee: Kamyr, Inc.Inventors: J. Robert Prough, Louis O. Torregrossa, Ake Backlund
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Patent number: 4419184Abstract: A method of treating medium consistency paper pulp or the like with a treament gas, such as oxygen, is provided to achieve uniform treatment results. The treatment gas is added to the pulp in finely distributed small bubbles, and the density of the suspension is measured at at least one moment, or the average density is measured during at least one time period. The temperature and the pressure of the suspension corresponding to the density measurements are determined, and the rest gas content of the substance is calculated at the actual moments or time periods based upon the measurements in the preceding steps. The gas consumption is then calculated as the difference between the quantity of gas added, and the residual gas quantity, or between two residual gas quantities. The gas addition step is controlled based upon the calculated consumption to obtain substantially uniform treatment results.Type: GrantFiled: July 20, 1981Date of Patent: December 6, 1983Assignee: Kamyr ABInventor: Ake Backlund