Method and device for loading a fibrous stock suspension

Abstract

The present invention relates to a method and a device for loading a fibrous stock suspension including a plurality of cellulose fibers with calcium carbonate. The method includes adding calcium hydroxide in liquid or dry form and/or calcium oxide into the fibrous stock suspension, adding carbon dioxide into the fibrous stock suspension, and precipitating calcium carbonate from calcium hydroxide through carbon dioxide in a pressurized vessel.

1 . A method for loading a fibrous stock suspension including a plurality of cellulose fibers with calcium carbonate, said method comprising the steps of: 
 adding at least one of calcium hydroxide in one of liquid and dry form and calcium oxide into the fibrous stock suspension;    adding carbon dioxide into the fibrous stock suspension; and    precipitating calcium carbonate from said calcium hydroxide through said carbon dioxide in a pressurized vessel.    
   
   
       2 . The method in accordance with  claim 1 , further comprising the step of supplying an aqueous fiber raw material with a consistency of between 1 and 20% fiber stock component into said pressure vessel.  
   
   
       3 . The method in accordance with  claim 2 , wherein said aqueous fiber raw material is an aqueous paper raw material.  
   
   
       4 . The method in accordance with  claim 2 , wherein said fiber stock component includes a low consistency fiber stock material at a content of between 1 and 6%.  
   
   
       5 . The method in accordance with  claim 2 , wherein said fiber stock component includes a medium consistency fiber stock material at a content of between 6 and 10%.  
   
   
       6 . The method in accordance with  claim 2 , wherein said fiber stock component includes a high consistency fiber stock material at a content of between 10 and 20%.  
   
   
       7 . The method in accordance with  claim 2 , wherein said aqueous fiber raw material is diluted to the fibrous stock suspension having a consistency of between 0.1 and 20%.  
   
   
       8 . The method in accordance with  claim 2 , wherein said aqueous fiber raw material is diluted to the fibrous stock suspension having a consistency of between 2 and 18%.  
   
   
       9 . The method in accordance with  claim 1 , wherein said pressure vessel is closed by a sluice after introducing at least one of an aqueous fiber stock material and a dilution water.  
   
   
       10 . The method in accordance with  claim 9 , wherein at least one of said calcium hydroxide and said calcium oxide is mixed into said aqueous fiber stock material within a range of between 0.1 and 60% of an existing solids content of a volume of a dry fiber stock.  
   
   
       11 . The method in accordance with  claim 10 , wherein the method is carried out at a pH value of between 6 and 11.  
   
   
       12 . The method in accordance with  claim 10 , wherein the method is carried out at a pH value of between 6.5 and 10.5.  
   
   
       13 . The method in accordance with  claim 10 , wherein said calcium hydroxide includes a reactivity in a range of between 0.0005 and 30 minutes.  
   
   
       14 . The method in accordance with  claim 10 , wherein said calcium hydroxide includes a reactivity in a range of between 0.05 and 10 minutes.  
   
   
       15 . The method in accordance with  claim 1 , wherein said calcium carbonate is precipitated by adding said carbon dioxide within a pressure range of between 0 and 15 bar.  
   
   
       16 . The method in accordance with  claim 1 , wherein said calcium carbonate is precipitated by adding said carbon dioxide within a pressure range of between 0 and 6 bar.  
   
   
       17 . The method in accordance with  claim 1 , wherein at least one of the fibrous stock suspension and said carbon dioxide is heated by one of process water, dilution water, and steam during dissolution in the fibrous stock suspension.  
   
   
       18 . The method in accordance with  claim 1 , wherein at least one of the fibrous stock suspension and said carbon dioxide is heated by one of a fiber loading process and introducing heat energy from outside.  
   
   
       19 . The method in accordance with  claim 1 , wherein at least one of the fibrous stock suspension and said carbon dioxide is heated by one of a steam energy and an electrical energy.  
   
   
       20 . The method in accordance with  claim 1 , wherein said carbon dioxide is added one of prior to, during, and after adding one of said carbon dioxide, said calcium hydroxide, and said calcium oxide.  
   
   
       21 . The method in accordance with  claim 1 , wherein said pressure vessel is opened by one of a valve and a sluice one of prior to and after a fiber loading reaction.  
   
   
       22 . The method in accordance with  claim 1 , further comprising precipitating a plurality of loaded fibers, wherein an energy expenditure for said precipitating said plurality of loaded fibers is between 0.3 and 8 kWh/t.  
   
   
       23 . The method in accordance with  claim 22  wherein no refiner is used for a refining of a fiber stock.  
   
   
       24 . The method in accordance with  claim 22 , further comprising the step of refining a fiber stock inside said pressure vessel during a precipitation process.  
   
   
       25 . The method in accordance with  claim 1 , further comprising precipitating a plurality of loaded fibers, wherein an energy expenditure for said precipitating said plurality of loaded fibers is between 0.5 and 4 kWh/t.  
   
   
       26 . The method in accordance with  claim 25 , wherein no refiner is used for a refining of a fiber stock.  
   
   
       27 . The method in accordance with  claim 1 , wherein a process temperature is between—15 and 120° C.  
   
   
       28 . The method in accordance with  claim 1 , wherein a process temperature is between 20 and 90° C.  
   
   
       29 . The method in accordance with  claim 27 , wherein a plurality of rhombohedral, scalenohedron, and spherical crystals are formed.  
   
   
       30 . The method in accordance with  claim 29 , wherein said plurality of crystals include dimensions of between 0.05 and 5 μm.  
   
   
       31 . The method in accordance with  claim 29 , wherein said plurality of crystals include dimensions of between 0.3 and 2.5 μm.  
   
   
       32 . The method in accordance with  claim 1 , further comprising mixing the fibrous stock suspension with at least one mixing element including at least one of a static and a moving mixing element.  
   
   
       33 . The method in accordance with  claim 32 , wherein said at least one mixing element includes a rotating mixing element.  
   
   
       34 . A device for loading a fibrous stock suspension including a plurality of cellulose fibers with calcium carbonate, said device comprising: 
 an infeed device for supplying a fiber raw material; and    a pressure vessel, the device configured for adding at least one of calcium hydroxide in one of liquid and dry form and calcium oxide into the fibrous stock suspension, adding carbon dioxide into the fibrous stock suspension, and precipitating calcium carbonate from said calcium hydroxide through said carbon dioxide in a pressurized vessel.    
   
   
       35 . The device in accordance with  claim 34 , wherein said pressure vessel includes one of a sluice and a valve configured for feeding through said fiber raw material for producing the fibrous stock suspension with a plurality of loaded fibers.  
   
   
       36 . The device in accordance with  claim 34 , wherein said pressure vessel includes a plurality of inlets for at least one of dilution water, press water, calcium oxide, calcium hydroxide, and carbon dioxide.  
   
   
       37 . The device in accordance with  claim 34 , wherein said pressure vessel includes a rotor for mixing the fibrous stock suspension.