Multiple Feed and Multiple Discharge Refiner

Abstract

A refiner for refining lignocellulose containing fiber material has two substantially oppositely positioned refining elements (6, 6a, 6b, 9) with refining surfaces (8, 8a, 8b, 11, 11a, 11b) with blade bars (25, 27) and grooves (26, 28). Opposed refining surfaces face each other forming a refining chamber (15, 15a, 15b) which receives fiber material to be refined. The refiner has two feed channels (19a, 19b) for feeding into the refiner at least one fiber material fraction (FM1, FM2) to be refined, and two refining zones (21a, 21b) with at least one different refining surface characteristic between the refining zones (21a, 21b). Each refining zone (21a, 21b) is intended to refine one fiber material fraction (FM1, FM2) of the at least one fiber material fraction (FM1, FM2). There is at least one discharge channel (23, 23a, 23b) for discharging out of the refiner at least one flow of refined material.

I claim: 
     
         1 . A refiner for refining lignocellulose-containing fiber material, the refiner comprising:
 at least two substantially oppositely positioned refining elements each of said refining elements comprising at least one refining surface with blade bars and blade grooves, the refining surfaces of two substantially oppositely positioned refining elements facing toward each other and forming between them a refining chamber arranged to receive fiber material to be refined;   at least two feed channels for feeding into the refiner at least one fiber material fraction to be refined;   at least two refining zones with at least one different refining surface characteristic between the refining zones, each refining zone arranged to refine one fiber material fraction of the at least one fiber material fraction; and   a discharge channel respective each of said refining zones for discharging fiber material fractions refined at the refining zones out of the refiner as separate flows.   
     
     
         2 . The refiner of  claim 1  wherein the refiner further comprises:
 a first feed channel in the refiner connected to a source of a first fiber material fraction for feeding into the refiner; 
 a second feed channel in the refiner connected to a source of a second fiber material fraction for feeding into the refiner; and 
 a first refining zone in the refining chamber connected to the source of first fiber material fraction so as to refine the first fiber material fraction, and a second refining zone in refining chamber connected to the source of second fiber material fraction so as to refine the second fiber material fraction. 
 
     
     
         3 . The refiner of  claim 2  further comprising a stationary refining element and a rotatable refining element within the stationary refining element and substantially opposite to the stationary refining element such that the refining chamber is formed between opposing refining surfaces of the refining elements, and wherein the refiner, the refining elements and the refining chamber have an axial direction defined by an axis of rotation of the rotatable refining element and in the axial direction along the refining chamber are at a first end of the refining chamber and in the refining chamber a first refining zone extending toward a second end of the refining chamber for refining a first fiber material fraction from the source of first fiber material fraction and at the second end of the refining chamber a second refining zone extending toward the first end of the refining chamber for refining a second fiber material fraction from the source of second fiber material fraction, the second refining zone having at least one different refining surface characteristic relative to the first refining zone. 
     
     
         4 . The refiner of  claim 3  wherein the first feed channel is arranged to feed the first fiber material fraction into the first refining zone through the first end of the refining chamber, the second feed channel is arranged to feed the second fiber material fraction into the second refining zone through the second end of the refining chamber, and wherein the stationary refining element comprises at each refining zone at least one opening allowing the first fiber material and second fiber material refined at the respective refining zone arranged to discharge out of the refining chamber through the respective at least one opening. 
     
     
         5 . The refiner of  claim 4  wherein the first feed channel is arranged to feed the first fiber material fraction into a first inner volume of the rotatable refining element through a first end of the rotatable refining element;
 wherein the second feed channel is arranged to feed the second fiber material fraction into a second inner volume of the rotatable refining element through a second end of the rotatable refining element; 
 wherein the rotatable refining element comprises at each refining zone at least one opening allowing the fiber material fraction to be refined at the respective refining zone to be fed into the refining chamber at the respective refining zone through the respective at least one opening; and 
 wherein the stationary refining element comprises at each refining zone at least one opening allowing the fiber material fraction refined at the respective refining zone to discharge out of the refining chamber at the respective refining zone through the respective at least one opening. 
 
     
     
         6 . The refiner of  claim 2  wherein the refiner comprises a first stationary refining element and second stationary refining element with a rotatable refining element between the first stationary refining element and the second stationary refining element, the rotatable refining element having a first refining surface substantially opposite to a first refining surface of the first stationary refining element such a first refining chamber and a first refining zone is formed between the opposing first refining surface of the first stationary refining element and the refining surface of the rotatable refining element, and the second stationary refining element having a second refining surface such that a second refining chamber and a second refining zone is formed between the opposing second refining surface of the second stationary refining element and a second refining surface of the rotatable refining element, wherein at least one refining surface characteristic at the second refining zone is different from at least one refining surface characteristic at the first refining zone;
 wherein the refiner, the refining elements and the refining chambers have an axial direction defined by the rotation of the rotatable refining element, and in the axial direction a first end and a second end opposite to the first end; 
 wherein the first feed channel is arranged to feed the first fiber material fraction into the first refining chamber through at least one end of the first refining chamber; and 
 wherein the second feed channel is arranged to feed the second fiber material fraction into the second refining chamber through at least one end of the second refining chamber. 
 
     
     
         7 . The refiner of  claim 2  wherein the refiner is a conical refiner with conical refining elements having a first end of smaller diameter and a second end of larger diameter. 
     
     
         8 . The refiner of  claim 2  wherein the refiner comprises:
 a first stationary disc refining element and a rotatable disc refining element next to the first stationary disc refining element and substantially opposite to the first stationary disc refining element such that a first refining chamber forming a first refining zone is formed between the opposing refining surfaces of the first stationary disc refining element and the rotatable disc refining element; 
 a second stationary disc refining element next to the rotatable disc refining element on the opposite side of the rotatable disc refining element relative to the first stationary disc refining element, the second stationary disc refining element being substantially opposite to the rotatable disc refining element such that a second refining chamber forming a second refining zone is formed between the opposing refining surfaces of the rotatable disc refining element and the second stationary disc refining element; 
 wherein at least one refining surface characteristic at the second refining zone is different from the respective at least one refining surface characteristic at the first refining zone; and 
 wherein the first feed channel is arranged to feed the first fiber material fraction into the first refining chamber and the second feed channel is arranged to feed the second fiber material fraction into the second refining chamber. 
 
     
     
         9 . The refiner of  claim 6  wherein the respective discharge channel comprises a first discharge channel for discharging out of the refiner the first fiber material fraction refined at the first refining zone; and
 a second discharge channel for discharging out of the refiner the second fiber material fraction refined at the second refining zone. 
 
     
     
         10 . The refiner of  claim 9  wherein the refining surface characteristic is at least one of the following: a blade bar width, a blade groove width, a blade bar angle, a blade bar height, a blade groove depth, a shape of an opening and a size of an opening. 
     
     
         11 . A method for refining lignocellulose-containing fiber material with a refiner comprising at least two substantially oppositely positioned refining elements comprising the steps of:
 feeding into the refiner at least two flows of at least one fiber material fraction to be refined;   subjecting the at least two flows of the at least one fiber material fraction to different refining effects in the refiner to create a first refined fiber material fraction flow and a second refined fiber material fraction flow; and   discharging the first refined fiber material fraction flow and the second refined fiber material fraction flow out of the refiner as separate flows.   
     
     
         12 . The method of  claim 11  further comprising the step of forming the first refined fiber material fraction flow and the second refined fiber material fraction flow in a refining chamber between a stationary refining element and a rotatable refining element within the stationary refining element and substantially opposite to the stationary refining element;
 wherein the step of subjecting the at least two flows of the at least one fiber material fraction to different refining effects in the refiner to create the first refined fiber material fraction flow and the second refined fiber material fraction flow further comprises: sending a first fiber material fraction to a first refining zone of the refining chamber at a first end in a radial direction defined by the rotation of the rotatable refining element and refining said first refined fiber material fraction with a first refining surface, and sending a second fiber material fraction to a second refining zone of the refining chamber at a second and opposite end in the radial direction and refining said second refined fiber material fraction with a second refining surface which is different from the first refining surface; 
 wherein the step of discharging the first refined fiber material fraction flow is by discharging out of the refining chamber at the first refining zone through at least one opening arranged in the stationary refining element at the first refining zone and wherein the step of discharging the second refined fiber material fraction flow is by discharging out of the refining chamber at the second refining zone through at least one opening arranged in the stationary refining element at the second refining zone 
 
     
     
         13 . The method of  claim 12  wherein the first fiber material fraction to be refined is fed into an inner volume of the rotatable refining element through a first end of the rotatable refining element adjacent the first refining zone and into the refining chamber at the first refining zone through at least one opening arranged in the rotatable refining element at the first refining zone; and
 the second fiber material fraction to be refined is fed into an inner volume of the rotatable refining element through a second end of the rotatable refining element adjacent to the second refining zone and into the refining chamber at the second refining zone through at least one second opening arranged in the rotatable refining element at the second refining zone. 
 
     
     
         14 . A method as claimed in  claim 12  wherein the second fiber material fraction is qualitatively different from the first fiber material fraction.