Arrangement for ensuring uniform pressure distribution for a hydraulic roller press

Description

FIELD OF THE INVENTION

[0001] The invention relates to a roller press for grinding of specific materials such as cement raw materials, cement clinker and similar materials.BACKGROUND OF THE INVENTION

[0002] In cement and mineral industries, hydraulic roller press HRP is used to comminute the bigger solid particles into smaller particles by feeding the material input through the gap between the two parallel rollers which are rotating in opposite directions. The material is not only crushed by the two roller surfaces but also by the particles which are needing to be crushed, the method called interparticle crushing. ELD (Even Load Distributor) is an additional feature added to the HRP for utilizing the entire width of the roller for effective crushing of the material.

[0003] In the state of the art design of HRP, the ratio between roller diameter to roller width is very important because of a significant edge effect, i.e., the crushing effect is reduced at the edge of the rollers. This is due to the fact that the material escapes over the edges of the rollers thereby reducing the crushing pressure on the material towards the gap at the edges of the rollers. To solve this problem Even Load Distributor ELD is being used in HRP but following problems are observed Flat spring used in the existing prior art is not providing prestress and thereby the material escapes through the cheek plates. High deflection leads to failure of spring Curved spring has lesser fatigue life span

[0004] EP 2950931 A1 discloses a roller press for grinding of particulate material such as cement raw materials, cement clinker and similar materials, which roller press comprises two oppositely rotating rollers forming between them a roller gap and a co-rotating annular disc, which in concentric manner is attached to an end surface of one of the rollers by means of a number of resilient attachment elements and being movable in the direction of the roller axis, where the outer diameter of said annular disc is greater than the diameter of said one of the rollers, hence the annular disc in the area of the roller gap extends toward the other roller, thus covering at least part of the roller gap. The roller press is peculiar in that the inner diameter of the annular disc is smaller than the diameter of the roller, to which it is attached, thus overlapping the end surface of said roller, and that the resilient attachment elements are evenly distributed over the circumference of the annular disc and provided with spaces or openings there between. It is hereby obtained that the annular disc does not get stuck by material to be grinded or destructive forces damaging construction parts are not accumulated. This is due to the fact that material in the roller press according to the invention is allowed to escape from the area between the annular disc and the roller to which it is attached.

[0005] EP 2167234 A1 discloses a roller press for grinding particulate material such as cement raw materials, cement clinker and similar materials, the roller press having two oppositely rotating rollers with one roller being movably supported relative to the other roller and with the rollers forming between them a roller gap. A co-rotating annular disc is attached to one of the rollers, which subject to actuation by a number of springs, is movable in the direction of the roller axis and which, in the area around the roller gap extends over the end surface of the other roller. The annular disc is divided into a number of ring sectors over its circumference, each individually biased by springs towards the end surface of the other roller. Hence, it is possible to maintain the grinding bed thickness at the ends of the rollers, thereby attaining a uniform pressure distribution across the rollers, as well as uniform grinding efficiency and uniform wear on the rollers.

[0006] DE 4037816 A1 discloses a process related to rollers used in metal rolling operations esp. in rolling presses or mills. Existing methods of preventing metal from leaving the sides of the roller gap utilize side checks which form an integral part of a material feed chute. Angular changes in roller axis position leads to jamming of metal between the cheeks and the roller and eventually machine shutdown. An improved sealing method for the roller gap uses an annular ring seal which is mounted at the side of one roller and has freedom of movement in the roller axis direction. The ring covers both the roller gap and part of the edge of the opposing roller. The arrangement is used to seal the sides of the gap between rotating rollers, esp. in rolling mills, does not require frequent exchange due to wear and prevents machine shut down due to jamming,OBJECT OF THE INVENTION

[0007] It is an object of the present invention to overcome or at least alleviate one or more of the above problems of the prior art and / or provide the consumer with a useful or commercial choice.

[0008] It is an object of the present invention to provide a roller press for grinding of specific materials such as cement raw materials, cement clinker and similar materials.

[0009] It is another object of the present invention to provide an even load distributor assembly ELD.

[0010] It is a further object of the present invention to provide an alternative to the prior art.SUMMARY OF THE INVENTION

[0011] In a first aspect, the invention relates to a roller press for grinding of specific materials such as cement raw materials, cement clinker and similar materials, said roller press comprising two parallelly arranged rollers, a fixed roller and a movable roller, said rollers configured to rotate in opposite direction towards each other and separated by a gap, said fixed roller comprising an even load distributor assembly ELD, said ELD assembly comprising an outer ring and an inner ring, said inner ring being fixed on said fixed roller by a fastening means such as a screw, said inner ring and said outer ring being connected by means of one or more bank of spring plates, said bank of spring plates being fixed at an angle Θ varying from 0 degrees to 60 degrees, said angle θ being an angle measured between a center line of said spring plate and a line which connects a roller center point and center point of said spring plate, said outer ring comprising deflection sensing rings.

[0012] By the features of the present invention even load distribution for crushing is achieved by using the co-rotating rings at both ends of the fixed roller, which are preferably mounted to the fixed roller by means of spring plate and one more fixed ring, which holds all the spring plates on it. The inner ring is preferably fixed on the fixed roller on each side of the fixed roller and the pre-stressing on the ELD ring is achieved by offset in planar surfaces allowing the springs to be deflected back when it is in operation ensuring material is not flowing through.

[0013] The prestress may be achieved by making the flat spring plates deflect in such a way that the spring action due to the material virtue will push and retain the feed material.

[0014] The resilient element may comprise multiple spring plates, preferably made of steel. It's a bank of spring plates added to reduce the deflection of the annular disc. The main advantage is that the number of bank of spring plates can be added during commissioning time or during the time of increase in production to decrease the deflection of the overall annular disc and increase the life of the spring plates. The stiffness is varied by varying the number of spring plates.

[0015] The resilient element bank of spring plates are not connected radially on the roller end surface. They are preferably tilted at an angle to the radial direction of the rollers. The advantage is to utilize the resiliency of the increased length of the spring plate in reducing the bending stress due to reducing the distance of action of force to the mounting location.

[0016] The deflection sensing ring may comprise an inner support ring and an outer support ring, the inner support ring being mounted on the outer ring by a fastening mechanism. The outer support ring is preferably being mounted on the inner support ring by a fastening mechanism.

[0017] The inner support ring may be mounted on the outer ring by a screw with a pin hole and nut and / or by a welded joint. The outer support ring may be mounted on the inner support ring by a screw with pin hole and nut and / or by a welded joint.

[0018] The inner ring is preferably assembled with the outer ring in such a way that it has a differential distance between planer surfaces of the outer ring and the inner ring.

[0019] The differential distance has an influence on the pre-load exerted on the fixed roller. The preload caused by this differential distance will ensure that the roller press resists the axial forces created due to the grinding of the material in addition to the stiffness created by the bank of springs. This will also ensure that there is always material retained equal to the amount of axial force that it creates.

[0020] A plurality of spring plates, preferably ranging from 1 to 10, is arranged in the bank of spring plates so as to provide variable stiffness to the structure by changing the number of springs plates.

[0021] An even load distributor assembly ELD, according to the present invention, preferably comprises an outer ring and an inner ring. The inner ring may be fixed on the fixed roller by a screw. The inner ring and the outer ring is preferably being connected by means of one or more bank of spring plates. The bank of spring plates is preferably being fixed at an angle Θ varying from 0 degrees to 60 degrees, said angle θ being an angle measured between a center line of said spring plate and a line which connects a roller center point and center point of said spring plate. The outer ring may comprise deflection sensing rings.

[0022] In a second aspect the invention relates to a method for even load distributing material in a roller press for grinding of specific materials such as cement raw materials, cement clinker and similar materials. The method preferably utilizes an even load distributor according to the first aspect of the invention.

[0023] The first and second aspect of the invention may me combined.BRIEF DESCRIPTION OF THE FIGURES

[0024] The figures show one way of implementing the present invention and is not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set. FIGURE 1 schematically illustrates a roller press for grinding of specific materials according to the present invention. FIGURE 2 schematically illustrates a roller press for grinding of specific materials according to the present invention from an alternative view. FIGURE 3 schematically illustrates a roller press for grinding of specific materials according and an ELD assembly to the present invention. FIGURE 4 schematically illustrates a bank of spring plates and a spring plate according to the present invention. FIGURE 5 schematically illustrates an ELD assembly according to the present invention. FIGURE 6 schematically illustrates a bank of spring plates mounted on an ELD assembly according to the present invention. FIGURE 7 schematically illustrates a bank of spring plates mounted on an ELD assembly according to the present invention. FIGURE 8 schematically illustrates a bank of spring plates mounted on an inner ring of an ELD assembly according to the present invention. FIGURE 9 schematically illustrates an ELD assembly according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] Figure 1 schematically illustrates a preferred embodiment of the roller press for grinding of specific materials according to the present invention.

[0026] In figure 2 and figure 3, the roller press for grinding of specific materials and an ELD assembly according to the present invention is schematically illustrated from an alternative view.

[0027] On figures 1-3 a roller press 1 for grinding of specific materials such as cement raw materials, cement clinker and similar materials is disclosed. The roller press 1 comprises two parallelly arranged rollers 2, 3; a fixed roller 2 and a movable roller 3. The rollers 2, 3 are configured to rotate in opposite direction towards each other and separated by a gap 20. The fixed roller 2 comprises an even load distributor assembly ELD 4. On figure 5 an embodiment of the ELD assembly according to present invention is disclosed. The ELD assembly 4 comprises an outer ring 5 and an inner ring 6. The inner ring 6 being fixed on the fixed roller 2 by a fastening means 7 such as a screw. The inner ring 6 and the outer ring 5 being connected by means of one or more bank of spring plates 8. The bank of spring plates 8 being fixed at an angle Θ varying from 0 degrees to 60 degrees. The outer ring 5 comprising deflection sensing rings 9.

[0028] Figure 5 schematically illustrates an ELD assembly according to the present invention. The sensing ring 9 comprises an inner support ring 13 and an outer support ring 14. The inner support ring 13 being mounted on the outer ring 5 by a fastening mechanism. The outer support ring 14 being mounted on the inner support ring 13 by a fastening mechanism. In a preferred embodiment of the present invention, the inner support ring 13 is mounted on the outer ring 5 by a screw with a pin hole 10 and nut 11 and / or by a welded joint. The outer support ring 14 is mounted on the inner support ring 13 by a screw with pin hole 15 and nut 16 and / or by a welded joint.

[0029] The inner ring 6 is assembled with the outer ring 5 in such a way that it has a differential distance H 17 between a planer surfaces of the outer ring 5 and the inner ring 6. The differential distance H 17 has an influence on pre-load exerted on the fixed roller 2, the preload caused by this differential distance will ensure that the system resists the axial forces created due to the grinding of the material in addition to the stiffness created by the bank of springs. This will also ensure that there is always material retained equal to the amount of axial force that it creates.

[0030] Figure 4 schematically illustrates a bank of spring plates and a spring plate according to the present invention. A plurality of spring plates 18, ranging from 1 to 10, is arranged in the bank of spring plates 8 so as to provide variable stiffness to the structure by changing the number of springs plates 18. Figures 6, 7 and 8 schematically illustrates how the bank of spring plates is mounted to the inner ring 6 and the outer ring 5.

[0031] Figure 9 schematically illustrates how the angle Θ 12 is defined. The angle Θ 12 is measured between the center line of the spring plate 18 and the line which connects the roller center point and center point of the spring plate 18.

[0032] In a preferred embodiment of the present invention, an even load distributor assembly ELD 4 comprises an outer ring 5 and an inner ring 6. The inner ring 6 is fixed on the fixed roller 2 by a screw 7. The inner ring 6 and the outer ring 5 is connected by means of one or more bank of spring plates 8. The bank of spring plates 8 being fixed at an angle Θ varying from 0 degrees to 60 degrees. The outer ring 5 comprises deflection sensing rings 9. Figure 9 schematically illustrates the ELD assembly, disclosing the angle Θ 12.

[0033] The present invention also relates to a method for even load distributing material in a roller press 1 for grinding of specific materials such as cement raw materials, cement clinker and similar materials. The method utilizes an even load distributor according to any of the embodiments mentioned above.

[0034] Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. It should also be understood that the form of this invention as shown is merely a preferred embodiment. Various changes may be made in the function and arrangement of parts; equivalent means may be substituted for those illustrated and described; and certain features may be used independently from others without departing from the scope of the invention as defined in the following claims.References:

[0035] 1. Roller press 2. Fixed roller 3. Movable roller 4. ELD assembly 5. Outer ring 6. Inner ring 7. Screw (for fixed ring) 8. Bank of spring plates 9. Deflection sensing ring 10. Screw with pin hole 11. Nut 12. Θ - angle 13. Inner support ring 14. Outer support ring 15. Screw with pin hole 16. Nut 17. H - differential distance 18. Spring plate 19. Screw (for spring assembly) 20. Gap

Claims

1. A roller press (1) for grinding of specific materials such as cement raw materials, cement clinker and similar materials, said roller press (1) comprising two parallelly arranged rollers (2, 3), a fixed roller (2) and a movable roller (3), said rollers (2, 3) configured to rotate in opposite direction towards each other and separated by a gap (20), said fixed roller (2) comprising an even load distributor assembly ELD (4), said ELD assembly (4) comprising an outer ring (5), characterized in that said ELD assembly further comprises an inner ring (6), said inner ring (6) being fixed on said fixed roller (2) by a fastening means (7) such as a screw, said inner ring (6) and said outer ring (5) being connected by means of one or more bank of spring plates (8), said bank of spring plates (8) being fixed at an angle Θ varying from 0 degrees to 60 degrees, said angle Θ (12) being an angle measured between a center line of said spring plate (18) and a line which connects a roller center point and center point of said spring plate (18), said outer ring (5) comprising deflection sensing rings (9).

2. A roller press according to claim 1, wherein the deflection sensing ring (9) comprises an inner support ring (13) and an outer support ring (14), said inner support ring (13) being mounted on said outer ring (5) by a fastening mechanism, said outer support ring (14) being mounted on said inner support ring (13) by a fastening mechanism.

3. A roller press according to claim 2, wherein the inner support ring (13) being mounted on said outer ring (5) by a screw with a pin hole (10) and nut (11) and / or by a welded joint, said outer support ring (14) being mounted on the said inner support ring (13) by a screw with pin hole (15) and nut (16) and / or by a welded joint.

4. A roller press according to claims 1-3, wherein the inner ring (6) is assembled with said outer ring (5) in such a way that it has a differential distance H (17) between a planer surfaces of said outer ring (5) and said inner ring (6).

5. A roller press according to claim 4, wherein said differential distance H (17) has an influence on a pre-load exerted on said fixed roller (2), said preload caused by said differential distance will ensure that the roller press resists axial forces created due to the grinding of the material in addition to the stiffness created by the bank of spring plates.

6. A roller press according to claim 1, wherein a plurality of spring plates (18) ranging from 1 to 10 is arranged in said bank of spring plates (8) so as to provide variable stiffness to the structure by changing the number of springs plates (18).

7. An even load distributor assembly ELD (4), said ELD assembly (4) comprising an outer ring (5) and an inner ring (6), said inner ring (6) being fixed on said fixed roller (2) by a screw (7), said inner ring (6) and said outer ring (5) being connected by means of one or more bank of spring plates (8), said bank of spring plates (8) being fixed at an angle Θ varying from 0 degrees to 60 degrees, said angle Θ (12) being an angle measured between a center line of said spring plate (18) and a line which connects a roller center point and center point of said spring plate (18), said outer ring (5) comprising deflection sensing rings (9).

8. A method for even load distributing material in a roller press (1) for grinding of specific materials such as cement raw materials, cement clinker and similar materials, the method utilizing an even load distributor according to claim 7.