Bedplates having graduated openings for pulp processing units

Abstract

A bedplate for a pulp processing unit includes a plate having an upper axial surface, a lower axial surface, and plurality of openings extending through the plate from the upper axial surface to the lower axial surface. Each of the plurality of openings has a shape, a size, and an angle. The shape is the cross-sectional shape, the size is equal to the largest cross-sectional dimension, and the angle is an angle formed between a centerline of each of the plurality of openings and an axial line parallel to a center axis of the bedplate. The shape, the size, the orientation of the shape, the angle, or combinations thereof of the plurality of openings varies depending on a location of the opening on the bedplate. A pulp processing unit comprising the bedplate is also disclosed.

What is claimed is: 
     
         1 . A bedplate for a pulp processing unit, the bedplate comprising:
 a plate having an upper axial surface, a lower axial surface, and plurality of openings extending through the plate from the upper axial surface to the lower axial surface, wherein:
 each of the plurality of openings has a shape, a size, and an angle; 
 the shape is a cross-sectional shape of each of the plurality of openings in a plane perpendicular to a center axis of the bedplate; 
 the size is equal to a largest cross-sectional dimension of each of the plurality of openings; 
 the angle is an angle formed between a centerline of each of the plurality of openings and an axial line parallel to a center axis of the bedplate; and 
 the shape, the size, an orientation of the shape, the angle, or combinations thereof of the plurality of openings varies depending on a location of each of the plurality of openings on the bedplate. 
   
     
     
         2 . The bedplate of  claim 1 , wherein the size of each of the plurality of openings varies relative to a location of each of the plurality of openings on the flat plate. 
     
     
         3 . The bedplate of  claim 2 , wherein the size of each of the plurality of openings varies relative to a radial position of each of the plurality of openings from a center of the bedplate. 
     
     
         4 . The bedplate of  claim 3 , wherein the size of each of the plurality of openings decreases with increasing radial distance from each of the plurality of opening to the center of the bedplate. 
     
     
         5 . The bedplate of  claim 3 , wherein the plurality of openings comprises a first opening disposed at a first radial distance from the center of the flat plate and a second opening disposed at a second radial distance from the center of the flat plate, wherein:
 the first radial distance is greater than the second radial distance; and   the first opening has a first size that is less than a second size of the second opening.   
     
     
         6 . The bedplate of  claim 2 , further comprising a plurality of wear strips extending outward from the upper axial surface of the bedplate, wherein the size of each of the plurality of openings varies relative to an angular position of each of the plurality of openings with respect to the wear strips. 
     
     
         7 . The bedplate of  claim 6 , wherein the plurality of openings comprises a first opening and a second opening, wherein:
 the first opening and the second opening are at a same radial distance from the center of the bedplate;   the first opening has a first angular position relative to a reference wear strip and the second opening has a second angular position relative to the reference wear strip different from the first angular position; and   the first opening has a size that is different from a size of the second opening.   
     
     
         8 . The bedplate of  claim 2 , wherein the size of each of the plurality of openings varies relative to a proximity of each of the plurality of openings to a high pressure side of one of the plurality of wear strips. 
     
     
         9 . The bedplate of  claim 8 , wherein:
 each of the plurality of wear strips comprises the high pressure side and a low pressure side; and   at each radial distance from the center of the bedplate, the size of each of the plurality of openings increases with increasing angular distance from the high pressure side of each wear strip to the low pressure side of each adjacent wear strip.   
     
     
         10 . The bedplate of  claim 8 , wherein:
 each of the plurality of wear strips comprises the high pressure side and a low pressure side;   the bedplate comprises a first opening proximate the high pressure side of one of the plurality of wear strips and a second opening spaced farther from the high pressure side compared to the first opening; and   the first opening has a size that is less than a size of the second opening.   
     
     
         11 . The bedplate of  claim 2 , wherein the size of each of the plurality of openings varies depending on a radial position with respect to a center of the bedplate and an angular position with respect to the wear strips of each of the plurality of openings. 
     
     
         12 . The bedplate of  claim 1 , further comprising a plurality of wear strip openings, wherein each of the plurality of wear strip openings extends axially through one of the plurality of wear strips and the bedplate. 
     
     
         13 . The bedplate of  claim 1 , wherein the shape of each of the plurality of openings varies depending on a radial position, an angular position, or both of each of the plurality of openings on the bedplate. 
     
     
         14 . The bedplate of  claim 1 , wherein the orientation of the shape of each of the plurality of openings varies depending on a radial position, an angular position, or both of each of the plurality of openings on the bedplate. 
     
     
         15 . The bedplate of  claim 1 , wherein the angle of each of the plurality of openings varies depending on a radial position, an angular position, or both of each of the plurality of openings on the bedplate. 
     
     
         16 . The bedplate of  claim 15 , wherein the angle of each of the plurality of openings is from 0 degrees to 45 degrees. 
     
     
         17 . The bedplate of  claim 15 , further comprising a plurality of wear strips extending outward from the upper axial surface of the bedplate, wherein the angle of each of the plurality of openings varies relative to an angular position of each of the plurality of openings with respect to the wear strips. 
     
     
         18 . The bedplate of  claim 1 , wherein the plurality of openings each have a contour at the interface of the opening with the upper axial surface, the lower axial surface, or both, wherein a shape of the contour at the interface varies depending on a radial position, and angular position, or both of each of the plurality of openings on the bedplate. 
     
     
         19 . The bedplate of  claim 18 , wherein the contour at the interface is a chamfer, and a size, shape, or both of the chamfer changes depending on the radial position, the angular position, or both of each of the plurality of openings on the bedplate. 
     
     
         20 . A pulp processing unit for processing fibrous materials, the pulp processing unit comprising the bedplate of  claim 1 , wherein:
 the pulp processing unit further comprises a vessel and a rotor; and   the bedplate is arranged with the upper axial surface facing towards the rotor.