Conical inlet transition zone for mechanical refiners

Abstract

Conical inlet refiner elements for a mechanical refiner include: a conical stator element disposed between a feedstock inlet to the mechanical refiner and primary refining plates of the mechanical refiner; and a conical rotor element disposed between the feedstock inlet to the mechanical refiner and the primary refining plates, the conical rotor element configured to form an initial refining gap with the conical stator element. The conical stator element and the conical rotor element are configured to cause a radial change greater than zero but less than 90 degrees in a direction of an axial feedstock flow path through the initial refining gap at a feedstock inlet to a primary refining gap formed between the primary refining plates, where the primary refining gap formed between the primary refining plates lies in a plane that is approximately perpendicular to the axial feedstock flow path.

What is claimed is: 
     
         1 . Conical inlet refiner elements for a mechanical refiner, the conical inlet refiner elements comprising:
 a conical stator element disposed between a feedstock inlet to the mechanical refiner and primary refining plates of the mechanical refiner; and   a conical rotor element disposed between the feedstock inlet to the mechanical refiner and the primary refining plates, the conical rotor element configured to form an initial refining gap with the conical stator element,   wherein the conical stator element and the conical rotor element are configured to cause a radial change greater than zero but less than 90 degrees in a direction of an axial feedstock flow path through the initial refining gap at a feedstock inlet to a primary refining gap formed between the primary refining plates, and   wherein the primary refining gap formed between the primary refining plates lies in a plane that is approximately perpendicular to the axial feedstock flow path.   
     
     
         2 . The conical inlet refiner elements of  claim 1 , wherein the conical stator element and the conical rotor element are configured to cause the radial change in the direction of the axial feedstock flow path in a range of 10 degrees to 20 degrees. 
     
     
         3 . The conical inlet refiner elements of  claim 1 , wherein the conical stator element and the conical rotor element are configured to cause an approximately 15 degree radial change in the direction of the axial feedstock flow path. 
     
     
         4 . The conical inlet refiner elements of  claim 1 , wherein the conical rotor element comprises a set of rotor segments, each rotor segment comprising a series of bars and grooves defining a refining area. 
     
     
         5 . The conical inlet refiner elements of  claim 4 , wherein the series of bars and grooves of each rotor segment are formed at an angle in a range of 45 degrees to 60 degrees with respect to the axial feedstock flow path. 
     
     
         6 . The conical inlet refiner elements of  claim 4 , wherein the conical rotor element further comprises a conical rotor ring configured to mount the set of rotor segments to a rotor of the mechanical refiner at a predetermined angle in a radial direction with respect to an axial direction of the mechanical refiner. 
     
     
         7 . The conical inlet refiner elements of  claim 6 , wherein the predetermined angle is approximately 15 degrees. 
     
     
         8 . The conical inlet refiner elements of  claim 1 , wherein the conical stator element comprises a set of stator segments, each stator segment comprising a series of bars and grooves defining a refining area. 
     
     
         9 . The conical inlet refiner elements of  claim 8 , wherein the series of bars and grooves of each stator segment are formed at an angle in a range of 45 degrees to 60 degrees with respect to the axial feedstock flow path. 
     
     
         10 . The conical inlet refiner elements of  claim 8 , wherein the conical stator element further comprises a conical stator ring configured to mount the set of stator segments to a stator of the mechanical refiner at a predetermined angle in a radial direction with respect to an axial direction of the mechanical refiner. 
     
     
         11 . The conical inlet refiner elements of  claim 10 , wherein the predetermined angle is approximately 15 degrees. 
     
     
         12 . A mechanical refiner, comprising:
 conical inlet refiner elements including:
 a conical stator element disposed between a feedstock inlet to the mechanical refiner and primary refining plates of the mechanical refiner; and 
 a conical rotor element disposed between the feedstock inlet to the mechanical refiner and the primary refining plates, the conical rotor element configured to form an initial refining gap with the conical stator element, 
 wherein the conical stator element and the conical rotor element are configured to cause a radial change greater than zero but less than 90 degrees in a direction of an axial feedstock flow path through the initial refining gap at a feedstock inlet to a primary refining gap formed between the primary refining plates, 
 wherein the primary refining gap formed between the primary refining plates lies in a plane that is approximately perpendicular to the axial feedstock flow path. 
   
     
     
         13 . The mechanical refiner of  claim 12 , wherein the conical stator element and the conical rotor element are configured to cause the radial change in the direction of the axial feedstock flow path in a range of 10 degrees to 20 degrees. 
     
     
         14 . The mechanical refiner of  claim 12 , wherein the conical stator element and the conical rotor element are configured to cause an approximately 15 degree radial change in the direction of the axial feedstock flow path. 
     
     
         15 . The mechanical refiner of  claim 12 , wherein the conical rotor element comprises a set of rotor segments, each rotor segment comprising a series of bars and grooves defining a refining area, wherein the series of bars and grooves of each rotor segment are set at an angle in a range of 45 degrees to 60 degrees with respect to the axial feedstock flow path. 
     
     
         16 . The mechanical refiner of  claim 15 , wherein the conical rotor element further comprises a conical rotor ring configured to mount the set of rotor segments to a rotor of the mechanical refiner at a predetermined angle in a radial direction with respect to an axial direction of the mechanical refiner. 
     
     
         17 . The mechanical refiner of  claim 12 , wherein the conical stator element comprises a set of stator segments, each stator segment comprising a series of bars and grooves defining a refining area, wherein the series of bars and grooves of each stator segment are set at an angle in a range of 45 degrees to 60 degrees with respect to the axial feedstock flow path. 
     
     
         18 . The mechanical refiner of  claim 17 , wherein the conical stator element further comprises a conical stator ring configured to mount the set of stator segments to a stator of the mechanical refiner at an angle of approximately 15 degrees in a radial direction with respect to an axial direction of the mechanical refiner. 
     
     
         19 . A method for providing a conical inlet transition zone for a mechanical refiner, the method comprising:
 installing a conical stator element on a stator of the mechanical refiner between a feedstock inlet to the mechanical refiner and primary refining plates of the mechanical refiner; and   installing a conical rotor element on a rotor of the mechanical refiner between the feedstock inlet to the mechanical refiner and the primary refining plates, the conical rotor element configured to form an initial refining gap with the conical stator element,   wherein the conical stator element and the conical rotor element are configured to cause a radial change greater than zero but less than 90 degrees in a direction of an axial feedstock flow path through the initial refining gap of the conical inlet transition zone at a feedstock inlet to a primary refining gap formed between the primary refining plates,
 wherein the primary refining gap formed between the primary refining plates lies in a plane that is approximately perpendicular to the axial feedstock flow path. 
   
     
     
         20 . The method of  claim 19 , wherein the conical rotor element comprises a set of rotor segments mounted to the rotor at a predetermined angle in a radial direction with respect to an axial direction of the mechanical refiner, and
 wherein the conical stator element comprises a set of stator segments mounted to the stator at a predetermined angle in a radial direction with respect to an axial direction of the mechanical refiner,   wherein the predetermined angle is an angle in a range of 10 degrees to 20 degrees in a radial direction with respect to an axial direction of the mechanical refiner.