Roller mill with a scraper

Abstract

A roller mill (1) including a housing (2) having a milling-material inlet (3), at least one milling-material outlet (4), and at least two cambered rollers (5, 5′) which are each arranged in the housing (2) so as to be rotatable about a roller axis (6). At least one roller (5) is assigned a scraper (7). The scraper (7) has a blade (8) for scraping milling material from a roller surface (9) with a scraper edge (10) which extends over an entire length (L) of the blade (8), and comprises a holder (11) with a receiving region (12). The holder is arranged in the housing (2) so as to be tiltable about an axis (13) parallel to the roller axis. An elastic bearing (14) is arranged between the blade (8) and the receiving region (12).

Claims

1. A roller mill (1) comprising: a housing (2) having a milling-material inlet (3), at least one milling-material outlet (4), and at least two cambered rollers (5, 5′) which are each arranged in the housing (2) so as to be rotatable about a roller axis (6), wherein at least one roller (5) is assigned a scraper (7), and the scraper (7): has a blade (8) for scraping milling material from a roller surface (9) with a scraper edge (10) which extends over an entire length (L) of the blade (8), and comprises a holder (11) with a receiving region (12), the holder is arranged in the housing (2) so as to be tiltable about an axis (13) parallel to the roller axis, an elastic bearing (14) is arranged between the blade (8) and the receiving region (12), and wherein the receiving region (12) has the form of a groove (15), and the elastic bearing (14) is arranged at least between a groove wall (16) and the blade (8); wherein the blade (8) is arranged in such a way that the scraper edge (10) is parallel to the roller axis (6) when the blade (8) does not contact the roller surface.

2. The roller mill (1) as claimed in claim 1, wherein the elastic bearing (14) is arranged between the blade (8) and both groove walls (16, 16′).

3. The roller mill (1) as claimed in claim 1, wherein the blade (8) abuts on a groove bottom (17).

4. The roller mill (1) as claimed in claim 1, wherein the blade (8) and the elastic bearing (14) are held in a clamping profile (18) which is arranged in the receiving region (12).

5. The roller mill as claimed in claim 1, wherein the blade (8) has a ratio between a length (L) and width (B) of 1.6:1 to 300:1.

6. The roller mill (1) as claimed in claim 1, wherein the blade (8) has a ratio between the height (H) and the free height (FH) of more than 1:1 to 6:1.

7. The roller mill (1) as claimed in claim 1, wherein the blade (8) is arranged at an angle (a) of between 200 and 75° to the roller surface (9).

8. The roller mill (1) as claimed in claim 1, wherein the elastic bearing (14) is formed as an elastomer strip with a Shore 00 hardness of between 15 and 100.

9. The roller mill (1) as claimed in claim 1, wherein the holder is provided with a counterweight (19) by means of which the blade (8) can be tilted about the axis (13) and can be pressed against the roller surface (9).

10. The roller mill (1) as claimed in claim 1, wherein the scraper (7) is in operative connection with a lift-off device by means of which the blade (8) can be tilted about the axis (13) and can be moved away from the roller surface (9).

11. The roller mill (1) as claimed in claim 1, wherein the blade (8) is received over its entire length (L) in the receiving region (12).

12. The roller mill (1) as claimed in claim 1, wherein the blade (8) is arranged at an angle (a) of between 30° and 60° to the roller surface (9).

13. The roller mill (1) as claimed in claim 1, wherein the elastic bearing (14) is formed as an elastomer strip with a Shore 00 hardness of between 30 and 90.

14. The roller mill (1) as claimed in claim 1, wherein the blade (8) is arranged at an angle (a) of between 30° and 50° to the roller surface (9).

15. The roller mill (1) as claimed in claim 1, wherein the elastic bearing (14) is formed as an elastomer strip with a Shore 00 hardness of between 40 and 80.

Description

(1) The invention will be better described below on the basis of preferred exemplary embodiments in conjunction with the figures, in which:

(2) FIG. 1 shows a schematic sectional view of the roller mill according to the invention;

(3) FIG. 2 shows a schematic sectional view of the scraper according to a first preferred embodiment of the invention; and

(4) FIG. 3 shows a schematic sectional view of the scraper according to a second preferred embodiment of the invention.

(5) FIG. 1 schematically shows a roller mill 1 according to the present invention. The roller mill 1 comprises a housing 2 having a milling-material inlet, indicated by the arrow 3, and a milling-material outlet 4, also indicated by the arrow 4. In the housing 2 there are arranged two cambered rollers 5 and 5′ which are each mounted so as to be rotatable about a roller axis 6 or 6′ and can be driven in opposite directions by means of a drive (not illustrated). The direction of rotation of the rollers 5 and 5′ is indicated by a respective arrow.

(6) Directly downstream of a milling gap 20, each roller 5 or 5′ is assigned a scraper 7 or 7′. The scraper 7 of the roller 5 is shown separately in two possible variants in FIGS. 2 and 3.

(7) The scraper 7 of FIGS. 2 and 3 comprises a blade 8 which is formed from a flat metal profile having a length L, a width B and a height H. The longitudinal direction of the blade 8 is indicated by the vector L.

(8) In FIGS. 2 and 3, the blade 8 contacts a roller surface by way of a scraper edge 10 which is of pointed configuration. The blade 8 is arranged so as to be inclined at an angle α between a plane TE, which is tangential to the roller surface 9 at the contact point of the blade 8, and the blade 8.

(9) In the embodiment of FIGS. 2 and 3, the scraper 7 has a holder 11 which is arranged so as to be tiltable about an axis 13. The axis 13 runs parallel to the roller axis 6 or 6′ and remains parallel to the roller axis 6 or 6′ even when the roller axis is displaced, for example during a skewing of the rollers.

(10) In the embodiment of FIG. 2, the holder 11 comprises a receiving region 12 which is provided as a groove 15 having two groove walls 16 and 16′ which run parallel to one another and having a groove bottom 17 running perpendicularly thereto, which extend in the longitudinal direction L of the blade 8 (and thus of the holder 11). The blade 8 is arranged in the groove 15 and contacts the groove bottom 17 by the end directed away from the scraper edge. An elastomer strip 14 is arranged on both sides of the blade 8 between the respective groove wall 16 or 16′ and the blade 8, with the result that the blade 8 enjoys a certain freedom of movement in the groove 15 and in particular can be bent by a bending moment parallel to the height of the blade 8 and can adapt to the camber of the roller 5.

(11) FH denotes the free height of the blade 8 that corresponds to the height of the blade 8 that is not arranged between the elastomer strips 14.

(12) In order that the blade 8 can be pressed against the roller surface 9, the holder 11, as already explained above, is arranged so as to be tiltable about the axis 13. Moreover, the holder comprises a counterweight 19 which, by lever effect, causes the holder 11 to be tilted and the blade 8 to be pressed against the roller surface 9.

(13) The scraper 7 illustrated in FIG. 3 corresponds in terms of design substantially to the scraper 7 of FIG. 2 with the difference that the blade 8 and the elastomer strips 14 are arranged in a clamping profile 18, wherein the clamping profile 18 is plugged into the receiving region 12 of the holder 11.

(14) The clamping profile 18 takes the form of a plastics profile and has two profile walls 160 and 160′ which run parallel to one another and a profile bottom 170 running perpendicularly thereto, which correspond in their function to the groove walls 16 or 16′ and the groove bottom 17.

(15) The clamping profile 18 simplifies the placement of the blade 8 with the elastomer strips 14 into the receiving region 12.