Horizontal re-pulping apparatus for cellulose fibres

Abstract

A pulping apparatus includes a hollow mixing cylinder selected to retain a volume of pulping fluid and cellulose fibres therein. The mixing cylinder is journaled for rotation about a central axis oriented at approximately +20° from horizontal. In a preferred construction, the mixing cylinder is divided internally into at least two discrete mixing chambers configured to facilitate outward flow of defibred pulp from an infeed end of the cylinder to and outwardly from the outlet end. The mixing chamber adjacent the inlet end is delineated by an end cover which closes the inlet end, and by a first divider positioned across the cylinder interior. The next adjacent mixing chamber is delineated longitudinally by the distal-most divider of the end mixing chamber, and by a second further downstream divider spaced longitudinally therefrom. The dividers include at least one through-opening therethrough. The through-openings regulate the flow of pulp and fluid along the mixing cylinder, while maintaining minimum cellulose/fluid levels in each mixing chamber. The through-openings may be positioned in alignment with, or in an asymmetrical arrangement relative to the cylinder axis so as to move eccentrically relative thereto as the mixing cylinder rotates.

1 . A pulping apparatus for the hydration of recycled cellulose fibres comprising:
 a hollow mixing cylinder having a cylinder wall which extends radially about a central axis oriented at approximately ±10° from horizontal, the cylinder being mounted for rotation about the axis and extending longitudinally therealong from a proximal inlet end to a distal outlet end, and including   an end cover partially closing said inlet end, the end cover including an inlet opening spaced inwardly from said cylinder wall towards said axis;   a first divider extending laterally across an interior of said cylinder, the first divider being distally spaced from said end cover to define a first mixing chamber therebetween, a first flow passage formed through said first divider, the first flow passage having a first diameter;   a second divider extending laterally across an interior of the cylinder, the second divider being distally spaced from the first divider plate to define a second mixing chamber therebetween, a second flow passage formed through said second divider;   a hopper assembly for conveying said cellulose fibres into said cylinder through said inlet opening;   a drive assembly selectively actuable to rotate said cylinder about said axis.   
     
     
         2 . The apparatus as claimed in  claim 1  wherein each of the first flow passage and the second flow passage comprises a generally circular opening positioned in substantial alignment with the axis;
 the second flow passage having a diameter selected greater than the first diameter. 
 
     
     
         3 . The apparatus as claimed in  claim 1  wherein the first flow passage is asymmetrically positioned relative to said axis, whereby rotation of the cylinder moves at least part of the first flow passage eccentrically relative to the axis;
 the second flow passage being asymmetrically positioned relative to said axis, whereby rotation of the cylinder moves a part of the second flow passage eccentrically relative to the axis, and wherein the part of the second flow passage moved eccentrically has a greater area than the part of the first flow passage moved eccentrically; 
 
     
     
         4 . The apparatus of  claim 1  further including a fluid supply, for supplying a hydrating fluid into the interior of the cylinder;
 the first fluid flow passage permitting variable fluid flow therethrough and maintaining a first fluid level in the first mixing chamber as the cylinder is rotated, 
 the second fluid flow passage permitting variable fluid flow therethrough and maintaining a second fluid level in the second mixing chamber as the cylinder is rotated, the second fluid level being less than the first fluid level. 
 
     
     
         5 . The apparatus as claimed in  claim 3 , wherein the first and second dividers each comprise metal plates, the first fluid flow passage comprises a first circular opening having a diameter selected at between about 0.3 and 0.7 metres and having a centre offset a first radial distance from the axis, and the second fluid flow passage comprises a second circular opening having a diameter selected at between about 0.5 and 1.2 metres and having a centre offset a second radial distance from the axis, greater than the first distance. 
     
     
         6 . The apparatus as claimed in  claim 3 , further including a cap plate partially closing the outlet end, the cap plate spaced distally from the second divider and defining a third mixing chamber therebetween, an outlet flow passage formed through said cap plate, the outlet flow passage being asymmetrically positioned relative to the axis, whereby rotation of the cylinder moves a part of the outlet flow passage eccentrically relative to the axis, and where the part of the outlet flow passage moved eccentrically has a greater area than the part of the second flow passage moved eccentrically. 
     
     
         7 . The apparatus as claimed in  claim 1 , wherein said cellulose fibres comprise recycled cardboard and paper fibre. hopper assembly includes a feed auger operable to convey said recycled cardboard and paper fibres in a substantially continuous supply. 
     
     
         8 . The apparatus as claimed in  claim 3 , wherein said cellulose fibres comprise recycled and cardboard. 
     
     
         9 . The apparatus as claimed in  claim 1 , wherein said drive assembly includes a low horsepower electric motor having a horsepower selected less than about 50 bhp. 
     
     
         10 . The apparatus as claimed in  claim 9 , wherein each of the second mixing chamber and the third mixing chambers have a substantially smooth solid sidewall. 
     
     
         11 . The apparatus as claimed in  claim 8 , further including at least one vane member disposed in said first mixing chamber, the at least one cutting blade member configured to physically engage said cellulose and fibers and break-up said recycled paper and cardboard as the cylinder rotates about the axis. 
     
     
         12 . A pulping apparatus for cellulose fibres comprising:
 a hollow mixing cylinder having a cylinder wall which extends radially about a central axis oriented at approximately ±10° from horizontal, the cylinder being journaled for rotation about the axis and extending longitudinally therealong from a proximal inlet end to a distal outlet end;   an end cover partially closing said inlet end and including an inlet opening;   an infeed hopper assembly for conveying said cellulose fibres into said cylinder through said inlet opening;   a fluid supply for supplying a pulping fluid into said cylinder for admixture with said cellulose fibres;   a first divider plate disposed in said cylinder, the first divider plate being longitudinally spaced from said end cover to define a first mixing chamber therebetween, a first flow passage formed through said first divider plate, the first flow passage configured to maintain a first minimum fluid level in the first mixing chamber as said cylinder is rotated about said axis;   a second divider plate disposed in said cylinder, the second divider plate being remote from said end cover and longitudinally spaced from said first divider plate to define a second mixing chamber therebetween, a second flow passage formed through said second divider plate, the second flow passage configured to maintain a second minimum fluid level in the second mixing chamber as said cylinder is rotated about said axis, the second fluid level being less than the first fluid level;   a drive assembly selectively actuable to rotate said cylinder about said axis.   
     
     
         13 . The apparatus as claimed in  claim 12 , wherein the first fluid flow passage comprises a first circular opening having a diameter selected at between about 0.3 and 0.7 metres;
 the second fluid flow passage comprises a second circular opening having a diameter selected at between about 0.5 and 1.2 metres.   
     
     
         14 . The apparatus as claimed in  claim 12  wherein each of the first and second flow passages having a centre which is offset from the axis to permit a variable fluid flow therethrough as the cylinder is rotated. 
     
     
         15 . The apparatus as claimed in  claim 14  wherein the centre of the second fluid flow passage is offset from the axis by a greater distance than that of the centre of the first fluid flow passage. 
     
     
         16 . The apparatus as claimed in  claim 13 , wherein the cylinder further includes a cap plate longitudinally spaced from the second divider plate and defining a third mixing chamber therebetween, an outlet flow opening formed through said cap plate;
 the outlet flow opening positioned to provide a fluid flow therethrough and maintain a third minimum fluid level in the third mixing chamber as the cylinder is rotated, the third fluid level being less than the second fluid level.   
     
     
         17 . The apparatus as claimed in  claim 12 , wherein said infeed hopper assembly includes a feed auger operable to convey recycled cardboard and paper waste into said cylinder as said cellulose fibres in a substantially continuous supply. 
     
     
         18 . The apparatus as claimed in  claim 13 , wherein said drive assembly includes a low horsepower electric motor having a horsepower selected at between about 20 and 35 bhp. 
     
     
         19 . The apparatus as claimed in  claim 18 , wherein said drive assembly further includes a chain drive for engagement with said mixing cylinder. 
     
     
         20 . A pulping apparatus for the hydration of recycled paper and cardboard fibres comprising:
 a hollow mixing cylinder having a generally solid cylinder wall which extends radially about a central axis oriented at approximately ±3° from horizontal, the cylinder being mounted for rotation about the axis and extending longitudinally therealong from a proximal inlet end to a distal outlet end and including;   an end cover partially closing said inlet end, the end cover including an inlet opening;   
       a first divider disposed in said cylinder, the first divider being distally spaced from said end cover and generally sealing with said cylinder wall to define a first mixing chamber therebetween, a first flow passage formed through said first divider, the first flow passage having a first diameter;
 a second divider being disposed in the cylinder, the second divider being distally spaced from the first divider and sealing with said cylinder wall to define a second mixing chamber therebetween, a second flow passage formed through said second divider; 
 an end cover distally spaced from the second divider and defining a third mixing chamber therebetween, an outlet flow opening formed through said end cover, the outlet flow opening having a third diameter selected greater than the second diameter; 
 an infeed hopper assembly for conveying a slurry of said recycled paper and cardboard fibres and a fluid into said cylinder through said inlet opening; 
 a drive assembly selectively actuable to rotate said cylinder about said axis. 
 
     
     
         21 . The apparatus as claimed in  claim 20  wherein each of the first flow passage and the second flow passage comprise a generally circular opening positioned in general co-axial alignment;
 the first flow passage maintaining a first fluid level in the first mixing chamber; 
 the second flow passage maintaining a second fluid level in the second mixing chamber less than the first fluid level. 
 
     
     
         22 . The apparatus as claimed in  claim 20  wherein the first flow passage is non-aligned with said axis, whereby rotation of the cylinder moves the first flow passage eccentrically relative to the axis;
 the second flow passage having a second diameter selected greater than the first diameter and being non-aligned with said axis, whereby rotation of the cylinder moves the second flow passage eccentrically relative to the axis; and 
 the outlet opening is non-aligned with said axis, whereby rotation of the cylinder moves the outlet flow opening eccentrically relative to the axis. 
 
     
     
         23 . The apparatus as claimed in  claim 21 , wherein said infeed hopper assembly includes a feed auger operable to convey said slurry into said first mixing chamber in a substantially continuous supply. 
     
     
         24 . The apparatus as claimed in  claim 22 , wherein the first fluid flow passage comprises a first circular opening having a diameter selected at between about 0.3 and 0.7 metres and having a centre offset a first radial distance from the axis; and
 the second fluid flow passage comprises a second circular opening having a diameter selected at between about 0.5 and 1.2 metres and having a centre offset a second radial distance from the axis, greater than the first distance.   
     
     
         25 . The apparatus as claimed in  claim 21 , wherein each of the second mixing chamber and the third mixing chambers have a substantially smooth solid sidewall. 
     
     
         26 . The apparatus as claimed in  claim 21 , further including at least one vane member disposed in said first mixing chamber, the at least one vane member configured for breaking-up said recycled paper and cardboard as the cylinder rotates about the axis. 
     
     
         27 . The apparatus as claimed in  claim 21 , wherein said drive assembly includes a low horsepower electric motor having a horsepower selected less than about 50 bhp.