Method and device for loading fibers in a fiber stock suspension with a filler

Abstract

A method and a device for loading of fibers that are contained in a fibrous suspension, with a filler by way of a chemical precipitation reaction. A fibrous suspension is supplied to a pump disperger where it is treated by shear forces in order to break down larger fiber agglomerates into smaller ones, and/or into individual fibers. At the same time the pump disperger serves as a reactor for the chemical precipitation reaction.

What is claimed is:  
     
         1 . A method for loading a plurality of fibers contained in a fiber stock suspension with a filler by a chemical precipitation reaction, comprising the steps of: 
 feeding the fiber stock suspension into a pump disperger;    treating the fiber stock suspension in said pump disperger by shear forces to break down at least one larger fiber agglomerate in the fiber stock suspension into at least one of a plurality of smaller fiber agglomerates and a plurality of individual fibers; and    reacting the fiber stock suspension in said pump disperger during the chemical precipitation reaction.    
     
     
         2 . The method of  claim 1 , wherein said pump disperger includes a reaction channel, and a flow speed of the fiber stock suspension is reduced in said reaction channel.  
     
     
         3 . The method of  claim 1 , wherein the fiber stock suspension has a radial direction in said pump disperger, said pump disperger includes both a central radial inner area and an outside, said radial direction originates from said central radial inner area to said outside.  
     
     
         4 . The method of  claim 3 , further including a concentration gradient in the fiber stock suspension, said concentration gradient originating from said central radial inner area, said concentration gradient being between approximately 50% and 0.1%.  
     
     
         5 . The method of  claim 4 , wherein said concentration gradient is between approximately 35% and 2%.  
     
     
         6 . The method of  claim 4 , wherein said concentration gradient is between approximately 35% and 4%.  
     
     
         7 . The method of  claim 1 , wherein said pump disperger includes a radial outer area, the fiber stock suspension is diluted with water in said radial outer area.  
     
     
         8 . The method of  claim 1 , wherein said pump disperger includes a reaction channel, said reaction channel is at least partially defined by a plurality of structured surfaces.  
     
     
         9 . The method of  claim 8 , wherein said plurality of structured surfaces are formed by at least one of a plurality of toothed fillings and a plurality of knife fillings.  
     
     
         10 . The method of  claim 1 , wherein said pump disperger includes both a reaction channel, an outside and at least one of a first plate, a second plate, a first structured surface and a second structured surface, said reaction channel is formed at one of between a first plate and a second plate and between a first structured surface and a second structured surface, said first plate is positioned opposite said second plate, said first plate rotates relative said second plate, said first structured surface is positioned opposite said second structured surface, said first structured surface rotates relative said second structured surface, the fibrous suspension in said reaction channel is transported essentially in a radial direction toward said outside of said pump disperger.  
     
     
         11 . The method of  claim 1 , further including both a throughput time for the fibrous suspension flowing through said pump disperger and a corresponding reaction time, both said throughput time and said reaction time are between approximately 0.01 min. and 1 min.  
     
     
         12 . The method of  claim 1 , further including both a throughput time for the fibrous suspension flowing through said pump disperger and a corresponding reaction time, both said throughput time and said reaction time are between approximately 0.1 sec. and 10 sec.  
     
     
         13 . The method of  claim 1 , wherein said pump disperger includes a plurality of plates, at least one said plate has a diameter of between approximately 0.5 m and 2 m.  
     
     
         14 . The method of  claim 1 , wherein said pump disperger includes a plurality of plates, each said plate is positioned opposite another said plate, each said plate rotates relative another said plate, at least one said plate has a radial outer relative speed of between approximately 20 m/sec. and 100 m/sec.  
     
     
         15 . The method of  claim 14 , wherein said radial outer relative speed is between approximately 40 m/sec and 60 m/sec.  
     
     
         16 . The method of  claim 1 , wherein said pump disperger includes a plurality of plates, each said plate is positioned opposite another said plate, each said plate rotates relative another said plate, at least one said plate has a distance from another said plate of between approximately 0.5 mm and 100 mm.  
     
     
         17 . The method of  claim 16 , wherein said distance is between approximately 25 mm and 50 mm.  
     
     
         18 . The method of  claim 1 , wherein the fiber stock suspension is compressed by a formation of a plug of the fiber stock suspension, said plug of the fiber stock suspension is fed to said pump disperger, said pump disperger dissolves said plug.  
     
     
         19 . The method of  claim 1 , wherein the filler is a precipitated calcium carbonate.  
     
     
         20 . The method of  claim 1 , wherein at least one of a calcium oxide and a calcium hydroxide is added to the fiber stock suspension, the fiber stock suspension is compressed by a formation of a plug of the fiber stock suspension, said plug of the fiber stock suspension is fed to said pump disperger, said pump disperger dissolves said plug, said plug has a disperger side end area, said pump disperger has both an infeed side and a central radial inner area, a carbon dioxide is added in at least one of said disperger side end area, said infeed side and said central radial inner area, said pump disperger is utilized as said reactor to transform at least one of said calcium oxide, said calcium hydroxide, and said carbon dioxide into a plurality of reaction products, said plurality of reaction products include a calcium carbonate and water, said pump disperger includes a reaction channel, the fiber stock suspension in said reaction channel includes a reduced flow speed.  
     
     
         21 . The method of  claim 1 , wherein said reacting step occurs at a consistency of between approximately 25% and 35%.  
     
     
         22 . The method of  claim 1 , wherein said reacting step occurs at a consistency of between approximately 30% and 35%.  
     
     
         23 . The method of  claim 1 , wherein the fiber stock suspension is compressed by a formation of a plug of the fiber stock suspension, said plug of the fiber stock suspension is fed to said pump disperger, said pump disperger includes a rotating swirl cross, said rotating swirl cross dissolves said plug.  
     
     
         24 . The method of  claim 1 , wherein said pump disperger includes a reaction channel, the fiber stock suspension in said reaction channel includes both a flow speed and a through-flow time, both a reduction of said flow speed and a selection of said through-flow time occur to provide an at least essentially completed said chemical precipitation reaction at an end of a flow of the fiber stock suspension through said reaction channel.  
     
     
         25 . The method of  claim 1 , further including the step of mixing at least one of a calcium oxide and a calcium hydroxide to the fiber stock suspension in a mixing vessel prior to one of said feeding step and a compressing the fiber stock suspension into a plug.  
     
     
         26 . The method of  claim 25 , further including the step of supplying the fiber stock suspension and at least one of said calcium oxide and said calcium hydroxide to said mixing vessel.  
     
     
         27 . The method of  claim 25 , wherein said mixing step includes a dwell time in said mixing vessel, said dwell time is between approximately 0.5 minutes and 4 hours.  
     
     
         28 . The method of  claim 25 , wherein said mixing step includes a dwell time in said mixing vessel, said dwell time is between approximately 3 minutes and 1 hour.  
     
     
         29 . The method of  claim 1 , wherein one of the fiber stock suspension is produced by dissolving at least one of a pulp and waste paper with additives in a pulper, and the fiber stock suspension is supplied to a loading process as a non-dried fiber material.  
     
     
         30 . The method of  claim 29 , wherein in said non-dried fiber material is from an additional pulp plant.  
     
     
         31 . The method of  claim 1 , further including the step of thickening the fiber stock suspension to within a range of consistency of approximately 50% by dewatering the fiber stock suspension before one of said feeding step and a compressing of the fiber stock suspension into a plug.  
     
     
         32 . The method of  claim 1 , further including the step of adjusting a pH value of the fiber stock suspension through an addition of a carbon dioxide.  
     
     
         33 . The method of  claim 32 , wherein said pump disperger includes a discharge area, said carbon dioxide is added in said discharge area.  
     
     
         34 . The method of  claim 1 , wherein at least one of a calcium oxide and a calcium hydroxide is added to the fiber stock suspension and combined with a carbon dioxide to produce a plurality of reaction products during the chemical precipitation reaction, said plurality of reaction products include calcium carbonate and water, the fiber stock suspension includes a pH value, said pH value is at least one of adjusted and controlled.  
     
     
         35 . The method of  claim 34 , wherein said pH value is both measured at an end of the chemical precipitation reaction and compared with a desired value, a deviation between said pH value and said desired value is one of reduced and eliminated through at least one of manipulating an addition of said calcium hydroxide, manipulating an addition of said carbon dioxide and manipulating a stock throughput, said chemical precipitation reaction is considered started at a pH-value of between approximately 10 and 13, said chemical precipitation reaction is considered complete when said pH-value reaches approximately 7.5.  
     
     
         36 . A device for loading a plurality of fibers contained in a fiber stock suspension with a filler by a chemical precipitation reaction, comprising: 
 a pump disperger, the fiber stock suspension being supplied to said pump disperger, the fiber stock suspension being treated in said pump disperger by shear forces to break down at least one larger fiber agglomerate in the fiber stock suspension into at least one of a plurality of smaller fiber agglomerates and a plurality of individual fibers, said pump disperger serving as a reactor for the chemical precipitation reaction.    
     
     
         37 . The device of  claim 36 , wherein said pump disperger includes a reaction channel, and a flow speed of the fiber stock suspension is reduced in said reaction channel.  
     
     
         38 . The device of  claim 36 , wherein the fiber stock suspension has a radial direction in said pump disperger, said pump disperger includes both a central radial inner area and an outside, said radial direction originates from said central radial inner area to said outside.  
     
     
         39 . The device of  claim 38 , further including a concentration gradient in the fiber stock suspension, said concentration gradient originating from said central radial inner area, said concentration gradient being between approximately 50% and 0.1%.  
     
     
         40 . The device of  claim 39 , wherein said concentration gradient is between approximately 35% and 2%.  
     
     
         41 . The device of  claim 39 , wherein said concentration gradient is between approximately 35% and 4%.  
     
     
         42 . The device of  claim 36 , wherein said pump disperger includes a radial outer area, the fiber stock suspension is diluted with water in said radial outer area.  
     
     
         43 . The device of  claim 36 , wherein said pump disperger includes a reaction channel, said reaction channel is at least partially defined by a plurality of structured surfaces.  
     
     
         44 . The device of  claim 43 , wherein said plurality of structured surfaces are formed by at least one of a plurality of toothed fillings and a plurality of knife fillings.  
     
     
         45 . The device of  claim 36 , wherein said pump disperger includes both a reaction channel, an outside and at least one of a first plate, a second plate, a first structured surface and a second structured surface, said reaction channel is formed at one of between a first plate and a second plate and between a first structured surface and a second structured surface, said first plate is positioned opposite said second plate, said first plate rotates relative said second plate, said first structured surface is positioned opposite said second structured surface, said first structured surface rotates relative said second structured surface, the fibrous suspension in said reaction channel is transported in an essentially radial direction toward said outside of said pump disperger.  
     
     
         46 . The device of  claim 36 , further including both a throughput time for the fibrous suspension flowing through said pump disperger and a corresponding reaction time, both said throughput time and said reaction time are between approximately 0.01 min. and 1 min.  
     
     
         47 . The device of  claim 36 , further including both a throughput time for the fibrous suspension flowing through said pump disperger and a corresponding reaction time, both said throughput time and said reaction time are between approximately 0.1 sec. and 10 sec.  
     
     
         48 . The device of  claim 36 , wherein said pump disperger includes a plurality of plates, at least one said plate has a diameter of between approximately 0.5 m and 2 m.  
     
     
         49 . The device of  claim 36 , wherein said pump disperger includes a plurality of plates, each said plate is positioned opposite another said plate, each said plate rotates relative another said plate, each said plate has a radial outer relative speed of between approximately 20 m/sec. and 100 m/sec.  
     
     
         50 . The device of  claim 49 , wherein said radial outer relative speed is between approximately 40 m/sec and 60 m/sec.  
     
     
         51 . The device of  claim 36 , wherein said pump disperger includes a plurality of plates, each said plate is positioned opposite another said plate, each said plate rotates relative another said plate, each said plate has a distance from another said plate of between approximately 0.5 mm and 100 mm.  
     
     
         52 . The device of  claim 51 , wherein said distance is between approximately 25 mm and 50 mm.  
     
     
         53 . The device of  claim 36 , further including a plug screw being installed prior to said pump disperger, said plug screw both compressing the fibrous suspension and forming a plug of the fibrous suspension.  
     
     
         54 . The device of  claim 53 , further including both an infeed screw and an essentially cylindrical channel, said infeed screw being located in cylindrical channel, said infeed screw preceding said plug screw.  
     
     
         55 . The device of  claim 54 , wherein said cylindrical channel includes a connection for admitting a mixture that includes at least one of the fibrous suspension, water, a calcium oxide and a calcium hydroxide.  
     
     
         56 . The device of  claim 53 , further including both a cone-shaped channel having a cross-section which tapers in a direction of material flow and a third channel connected to said cone-shaped channel, said third channel connected to said pump disperger, said plug screw rotating in said cone-shaped channel, said plug being formed in said third channel.  
     
     
         57 . The device of  claim 56 , wherein said third channel includes a feed screw.  
     
     
         58 . The device of  claim 57 , further including both an infeed screw and an essentially cylindrical channel, said infeed screw being located in cylindrical channel, said infeed screw preceding said plug screw, at least one of said cylindrical channel, said cone-shaped channel and said third channel being pressurized.  
     
     
         59 . The device of  claim 58 , wherein one of a) said infeed screw, said plug screw and said feed screw are mounted on a common drive shaft and b) each of said infeed screw, said plug screw and said feed screw can be at least partially driven separately.  
     
     
         60 . The device of  claim 58 , wherein said pump disperger is utilized as said reactor to transform at least one of said calcium oxide, said calcium hydroxide, and said carbon dioxide into a plurality of reaction products, said plurality of reaction products include a calcium carbonate and water.  
     
     
         61 . The device of  claim 36 , wherein said pump disperger includes a plurality of plates, each said plate is positioned opposite another said plate, each said plate rotates relative another said plate, at least one said plate has a radial outer relative speed which is adjustable.  
     
     
         62 . The device of  claim 36 , wherein said pump disperger includes a plurality of plates, at least one said plate has an absolute speed which is adjustable.  
     
     
         63 . The device of  claim 36 , further including both a swirl cross and a plug screw, said pump disperger includes at least one of a plate facing said plug screw and a structured surface facing said plug screw, said swirl cross being provided in a center of at least one of said plate and said structured surface, the fiber stock suspension including a plug, said swirl cross serves to loosen said plug and accordingly enlarge a plurality of surfaces of the fiber stock.  
     
     
         64 . The device of  claim 36 , further including a carbon dioxide connection, the fiber stock suspension including a plug, said carbon dioxide connection being positioned in an area where said plug is loosened so that carbon dioxide can be added in said area.  
     
     
         65 . The device of  claim 36 , wherein said pump disperger includes a plurality of structured surfaces, said plurality of structured surfaces creates a plurality of shear forces, at least one said shear force opposite another said shear force.  
     
     
         66 . The device of  claim 36 , wherein said pump disperger includes both an outlet and at least one of a plurality of plates and a plurality of structured surfaces, said outlet located essentially tangential to one of at least one said plate and at least one said structured surface, said outlet for a loaded fibrous suspension.  
     
     
         67 . The device of  claim 36 , further including a carbon dioxide supply line, said pump disperger having an outlet, said carbon dioxide supply line being connected in an area of said outlet.  
     
     
         68 . The device of  claim 36 , wherein said pump disperger includes both an inlet and at least one of a plurality of plates and a plurality of structured surfaces, said inlet located essentially tangential to one of at least one said plate and at least one said structured surface, said inlet for diluting a loaded stock with at least one of water and a calcium hydroxide to a ratio less than 6%.  
     
     
         69 . The device of  claim 68 , further including an upstream stock thickening unit providing said at least one of water and a calcium hydroxide.  
     
     
         70 . The device of  claim 68 , wherein said ratio is between approximately 4% and 6%.  
     
     
         71 . The device of  claim 68 , wherein said pump disperger includes a heating device influencing a reaction temperature.