Press roll for washing and/or dewatering pulp, and a method for manufacturing or repairing such a press roll
View Patent ↗Press rolls for washing or dewatering pulp are disclosed including a core, a mantle section attached around the core, at least one perforated roll plate extending around the circumference of the press roll, and including a plurality of mounting openings disposed between the end edges of the perforated roll plate and distributed around the entire circumference of the press roll, and a plurality of fixing pins corresponding to the mounting openings, each being anchored to the mantle section and surrounded by the corresponding plurality of mounting openings whereby movement of the perforated roll plate relative to the mantle section in a circumferential direction of the press roll is prevented.
1. A press roll for washing or dewatering pulp comprising an axially-extending core, a mantle section attached around said axially-extending core, a plurality of adjacent perforated roll plates disposed around said mantle section and contracted thereonto, each of said plurality of perforated roll plates extending around the entire circumference of said press roll so that each of said plurality of perforated roll plates includes a pair of circumferentially-extending edges and a pair of end edges that have been joined by welding, each of said plurality of perforated roll plates comprising a plurality of mounting openings disposed between said pair of end edges and distributed around the entire circumference of said press roll, and a plurality of fixing pins corresponding to said plurality of mounting openings, each of said plurality of fixing pins being anchored to said mantle section and being surrounded by said corresponding plurality of mounting openings, whereby movement of each of said plurality of perforated roll plates relative to said mantle section in a welded circumferential direction of said press roll is prevented.
2. The press roll of claim 1 , wherein said plurality of mounting openings are centrally disposed between said pair of circumferentially-extending edges of each of said plurality of perforated roll plates.
3. The press roll of claim 2 , wherein said plurality of mounting openings are disposed along the longitudinally-extending center line of each of said plurality of perforated roll plates.
4. The press roll of claim 1 , wherein said plurality of mounting openings are evenly distributed around said entire circumference of said press roll, whereby the distance between each adjacent one of said plurality of mounting openings is substantially the same.
5. The press roll of claim 1 , wherein said plurality of mounting openings comprises at least three mounting openings.
6. The press roll of claim 1 , wherein said mantle section includes a plurality of attachment holes corresponding to said plurality of mounting openings, each of said plurality of fixing pins including a fixing portion for anchoring in said corresponding plurality of attachment holes.
7. The press roll of claim 6 , wherein said fixing portion comprises threads.
8. The press roll of claim 6 , including a plurality of support ribs for attaching said mantle section to said axially-extending core, said plurality of support ribs extending substantially radially from said axially-extending core and distributed around the circumference of said axially-extending core, each of said plurality of mounting openings and its corresponding plurality of attachment holes being in radially alignment with one of said plurality of support ribs.
9. The press roll of claim 1 , wherein each of said plurality of mounting openings includes an inner surface having a size whereby a gap is provided between said inner surface of said plurality of mounting openings and said corresponding plurality of fixing pins.
10. A roll press for washing or dewatering pulp comprising a pair of press rolls defining a nip therebetween whereby pulp can be pressed in said nip, at least one of said pair of press rolls comprising the press roll of claim 1 .
11. A method for providing a press roll for washing or dewatering pulp, said press roll comprising an axially-extending core, and a mantle section attached around said axially-extending core, said method comprising contracting at least one perforated roll plate by cooling to said mantle section so that it extends around the entire circumference of said press roll, whereby said at least one perforated roll plate includes a pair of circumferentially-extending edges and a pair of end edges that have been joined by welding, drilling a plurality of mounting openings between said pair of end edges and distributed around the entire circumference of said press roll, inserting a plurality of fixing pins into each of said plurality of mounting openings, and anchoring each of said plurality of fixing pins in said mantle section, whereby said plurality of fixing pins are surrounded by said corresponding plurality of mounting openings, and movement of said at least one perforated roll plate relative to said mantle section in said circumferential direction of said press roll is prevented.
12. The method of claim 11 , wherein said attaching of said at least one perforated roll plate comprises providing said at least one perforated roll plate around said mantle section and contracting said at least one perforated roll plate thereabout.
13. The method of claim 11 , wherein said drilling of said plurality of mounting openings comprises drilling at positions centrally between said pair of circumferentially-extending edges of said at least one perforated roll plate.
14. The method of claim 13 , wherein said drilling of said plurality of mounting openings comprises drilling at positions along the longitudinal center line of said at least one perforated roll plate.
15. The method of claim 11 , wherein said drilling of said plurality of mounting openings comprises evenly distributing said plurality of mounting openings around the entire circumference of said press roll, whereby the distance between each adjacent one of said plurality of mounting openings is substantially the same.
16. The method of claim 11 , wherein said plurality of mounting openings comprises at least three mounting openings, and wherein said anchoring of each of said plurality of fixing pins comprises inserting said plurality of fixing pins into said at least three mounting openings thereby anchoring said plurality of fixing pins in said mantle section.
17. The method of claim 11 , including drilling a plurality of attachment holes corresponding to each of said plurality of mounting openings in said mantle section following said drilling of said plurality of mounting openings, and wherein each of said plurality of fixing pins includes a fixing portion, and including anchoring said fixing portion of each of said plurality of fixing pins in each of said plurality of attachment holes.
18. The method of claim 17 , wherein said fixing portion in each of said plurality of fixing pins comprises at least one threaded portion.
19. The method of claim 17 , including providing a plurality of support ribs for attaching said mantle section to said axially-extending core, and mounting said plurality of support ribs substantially radially from said axially-extending core and distributed around the circumference of said axially-extending core, each of said plurality of mounting openings and its corresponding attachment hole being in radial alignment with one of said plurality of support ribs.
20. The method of claim 11 , wherein each of said plurality of mounting openings includes an inner surface, and including drilling each of said plurality of mounting openings so as to provide a gap between said plurality of fixing pins and said inner surface of said plurality of mounting openings.