Roller crusher and method for arrangement thereof
A roller crusher having two generally parallel rollers arranged to rotate in opposite directions, towards each other, and separated by a gap, where each roller has two ends. The roller crusher includes a flange attached to at least one of the ends of one of the rollers and a movement blocking arrangement structured and arranged to limit the gap between the rollers to a minimum gap of at least 45 mm. The roller crusher further includes at least one scraper positioned at an end of the roller with a flange. The scraper is positioned such that a minimum roller surface distance between each scraping surface of the at least one scraper and the outer surface of the roller is at least 70% of the minimum gap. A method for arrangement of a roller crusher is also provided.
1. A roller crusher having two parallel rollers arranged to rotate in opposite directions, towards each other, and separated by a gap that is adjustable by movement of the two rollers toward and away from each other, each roller having two ends, the roller crusher comprising:
a flange attached to at least one of the ends of one of the rollers,
the flange extending in a radial direction of the roller,
the flange having a height (H) above an outer surface of the roller, and
a movement blocking arrangement structured and arranged to limit the gap between the rollers to a minimum gap of at least 45 mm,
wherein the roller crusher further comprises at least one scraper positioned at an end of the roller with the flange, and wherein the scraper is positioned such that a minimum roller surface distance between each scraping surface of the at least one scraper and the outer surface of the roller is within the range of 70% to 100% of the minimum gap, such that, when the roller crusher is in operation, the at least one scraper is allowed to partially wear down and thereby reduce in size at a magnitude being up to 30% of the minimum gap, thereby extending an individual wear life the at least one scraper.
2. The roller crusher as claimed in claim 1 , wherein the at least one scraper is positioned such that a minimum flange distance between each scraping surface of the at least one scraper and an inner surface of the flange is 1-25 mm.
3. The roller crusher as claimed in claim 1 , wherein the movement blocking arrangement is structured and arranged to limit the gap between the rollers to a minimum gap of at least 50 mm.
4. The roller crusher as claimed in claim 1 , wherein the at least one scraper is arranged at a lower part of the roller crusher.
5. The roller crusher as claimed in claim 4 , wherein the at least one scraper is arranged such that a scraping surface of the at least one scraper at least partly faces downwards for allowing removed material to leave from the roller and scraping surface by gravitational force.
6. The roller crusher as claimed in claim 1 , wherein the at least one scraper has a fastening position located at a distance from the outer surface of the roller, wherein the at least one scraper is arranged such that a position of a scraping surface of the at least one scraper is located at, or consecutive to, a radial axis which extends from a rotational axis of the roller and through the fastening position.
7. The roller crusher as claimed in claim 1 , wherein the roller crusher comprises at least two scrapers arranged consecutive to each other at the end of the roller with a flange for at least partially removing material accumulated on the flange and/or on the outer surface at the end of the roller.
8. The roller crusher as claimed in claim 7 , wherein the at least two consecutive scrapers have different minimum roller surface distances and/or wherein the at least two scrapers are each arranged such that a minimum flange distance between each scraping surface of the scraper and an inner surface of the flange is different for each scraper of the two or more scrapers.
9. The roller crusher as claimed in claim 7 , wherein the at least two consecutive scrapers are arranged such that their respective minimum roller surface distances decreases seen from a front scraper to consecutive scraper(s) and/or such that their respective minimum flange distances decreases seen from a front scraper to consecutive scraper(s).
10. The roller crusher as claimed in claim 1 , wherein a scraping surface of the at least one scraper is arranged such that a distance between the outer surface of the roller and the scraping surface decreases towards the flange.
11. The roller crusher as claimed in claim 1 , wherein the roller crusher further comprises at least one holding fixture for the at least one scraper, which at least one holding fixture connects to a frame of the roller crusher at respective fastening positions of, or at a common fastening position of, the at least one scraper.
12. The roller crusher as claimed in claim 11 , wherein the at least one holding fixture comprises at least one bracket and at least one wedge element, which wedge element is structured and arranged to attach the at least one scraper to the at least one bracket such that an angular position of the at least one scraper is shifted in relation to an angular position of the at least one bracket in a rotational plane of the roller.
13. The roller crusher as claimed in claim 1 , wherein the roller crusher further comprises a flexible retaining arrangement arranged to intercouple at least one of the at least one scraper with a frame of the roller.
14. The roller crusher as claimed in claim 1 , wherein each of the at least one scraper comprises a scraping element which comprises a wear-resistant material and which scraping element presents a scraping surface.
15. The roller crusher as claimed in claim 1 , wherein the roller crusher further comprises a remote material removal device configured to output a material removing beam towards a target area, wherein the remote material removal device and the at least one scraper are arranged consecutive to each other at an end of the roller with a flange for at least partially removing material accumulated on the flange and/or on the outer surface at the end of the roller.
16. The roller crusher as claimed in claim 15 , wherein a target area of the remote material removal device is located in front of the at least one scraper.
17. A method for arrangement of a roller crusher, which roller crusher has two parallel rollers arranged to rotate in opposite directions, towards each other, and separated by a gap that is adjustable by movement of the two rollers toward and away from each other, each roller having two ends, the roller crusher comprising:
a flange attached to at least one of the ends of one of the rollers,
the flange extending in a radial direction of the roller,
the flange having a height (H) above an outer surface of the roller, and
a movement blocking arrangement structured and arranged to limit the gap between the rollers to a predetermined minimum gap, wherein the method comprises:
positioning at least one scraper at an end of the roller with the flange such that a minimum roller surface distance between each scraper surface of the at least one scraper and the outer surface of the roller is within the range of 70% to 100% of the minimum gap, such that, when the roller crusher is in operation, the at least one scraper is allowed to partially wear down and thereby reduce in size at a magnitude being up to 30% of the minimum gap, thereby extending an individual wear life the at least one scraper.
18. The method as claimed in claim 17 , comprising positioning the scraper such that a minimum flange distance between each scraping surface of the at least one scraper and an inner surface of the flange is 1-25 mm.
19. The method as claimed in claim 17 , wherein the movement blocking arrangement is structured and arranged to limit the gap between the rollers to a minimum gap of at least 45 mm.