WO2016012028A1

WO2016012028A1 - A roller with a segmented wear surface for crushing particulate material

Info

Publication number: WO2016012028A1
Application number: PCT/DK2015/050224
Authority: WO
Inventors: Niels Ole Cedergaard
Original assignee: Flsmidth A/S
Priority date: 2014-07-25
Filing date: 2015-07-22
Publication date: 2016-01-28
Also published as: CN106573246A; EP3171980A1; CN106573246B; EP3171980B1

Abstract

Described is a roller (1) for crushing of particulate material, such as crude ore for use in the mineral industry, where the roller body (2) is provided with a plurality of individual wear segments (4, 5) which are arranged on longitudinal guiding means (6) and between clamps (7, 8) in a manner such that two or more of the wear segments (4, 5) are fixed to the same lateral section of one lateral portion of the roller body (2) and such that the frequency of, and cost associated with, the replacement of such wear segments is minimized. The invention also relates to the plurality of wear segments and to a method of manufacturing the roller.

Description

A ROLLER WITH A SEGMENTED WEAR SURFACE FOR CRUSHING

PARTICULATE MATERIAL

FIELD OF THE INVENTION

The present invention relates to a roller for the crushing of particulate material, such as crude ore for use in the cement or minerals industries, by which a roller body is provided with a plurality of individual wear segments which are arranged on longitudinal guiding means and between clamps such that two or more of the wear segments are fixed to the same lateral section of one lateral portion of the roller body in a manner such that the frequency of, and cost associated with, the replacement of such wear segments is minimized. The invention also relates to the plurality of individual wear segments and to a method of manufacturing the roller. The roller may for example be used in a vertical roller mill, in a high-pressure grinding roller press, or in similar equipment for crushing of particulate material.

BACKGROUND ART Historically, grinding rollers without wear segments (or grinding rollers with a uniform, one-piece wear piece) were required to be replaced every three to eight months (depending on the tip speed of the grinding rollers) because of excessive wear due to the impact of the grinding media and particulate against the rollers within the housing. Such a replacement process was (and is) time consuming. For example, it can take four to six hours or more to replace grinding rollers in a grinding mill, and a full change-out of all grinding rollers (albeit, seldom necessary) takes approximately sixteen hours or more. These time-consuming repair processes, if performed too often, may result in losses such as superfluous operational downtime, increased labor costs, and reduced throughput. If the repair process is performed too infrequently, other expensive losses such as shaft failure, inefficient grinding, and/or further degradation of intact grinding rollers or mill components may be incurred.

Additionally, such grinding rollers were typically very costly. For example, when an exotic high end wear surface was implemented, the entire roller was required to be fabricated out of the exotic high-end material. To reduce wear and to reduce the frequency of change-outs of grinding rollers, segmented crushing rollers were implemented. Such segmented crushing rollers also allowed for intermittent use of exotic high end wear segments (i.e. - using an exotic high end wear segment in one wear segment and not another). Examples of patents/applications that describe rollers having the outer circumference of the roller body covered with segmented wear segments are found in, for example, EP 2703085, DE 197 09 263 A1 , US 5,253,816 and US 5,860,609. In each of the foregoing patents/applications the rollers are arranged laterally on the roller body (i.e. - when the roller is viewed in the longitudinal direction so that the center axis of the rollers extends laterally through the center shaft of the roller body, the wear segments are arranged laterally on the circumference of the grinding roller so that a wear segment spans an entire lateral portion of the grinding roller).

When such segmented rollers are used in high pressure grinding applications, pressure build-up between neighboring segments will promote movement of the segments. Initially such movements will be small but after a period of time the movements will become significant and may eventually result in damage to the segments, the clamps or even the roller body. As a consequence hereof, such segments, clamps, roller surfaces or roller body must be repaired meaning that the entire grinding circuit often must be taken out of operation, which is very costly. As a result, numerous attempts have been made to make the gaps between wear segments non-existent and as small as possible.

For example, in US 2014/0158801 , such gaps are minimized or eliminated. In US 2014/0158801 , when the roller is viewed in the longitudinal direction so that the center axis of the rollers extends laterally through the center shaft of the roller body, the wear segments are arranged laterally on the circumference of the grinding roller so that a wear segment spans a single lateral portion of the grinding roller. However, in such an arrangement, when the outer half of a wear segments is worn down (which is typical in, for example, vertical roller mills) the entire wear segment is required to be replaced or refurbished. Moreover, in such an arrangement there is a non-uniform wear pattern which results in less efficient grinding and a loss of energy. Therefore, the foregoing design is not advantageous because it still results in a time-consuming repair process and may result in losses such as superfluous operational downtime, increased labor and material costs, and reduced throughput. The non-uniform wear will also result in non- optimal production and an increase in energy. I have determined that a new type of crushing roller, and wear segments therefor, are needed in order to reduce costs and time associated with the frequent repair and/or replacement of premature segmented discs. Additionally, a new type of crushing roller, and wear segments therefor, are needed in order to maintain a uniform wear across the full width of roller segments (in the lateral direction). Preferably, such new type of crushing rollers will allow for easy replacement or refurbishment when the outer half of wear segments (i.e. - the wear segments which are typically the most worn) need replacement and will provide for uniform wear in order to achieve and maintain optimum production and minimize the loss of energy throughout the life of the wear segments.

SUMMARY OF THE INVENTION

A roller is provided for crushing particulate material which includes a roller body 2 with a center axis 3, a plurality of wear segments 4, 5, having crushing surfaces, that are fixed to the roller body 2; a plurality of clamps 7, 8 disposed on the sides of the roller body 2; a guiding means 6 disposed on the roller body 2 between the clamps 7, 8; where the guiding means 6 run longitudinally and where the wear segments 4, 5 are arranged on the guiding means 6. The plurality of wear segments 4, 5 can include grooves 1 1 and knobs 12, the grooves 1 1 and knobs 12 cooperating with the guiding means 6 to fix the plurality of wear segments 4, 5 to the roller body 2. The roller 1 can also include a plurality of keys 10, the plurality of keys 10 being fixed to the roller body 2. The plurality of wear segments 4, 5 can also include keyways 13, the keyways 13 cooperating with the plurality of keys 10 to prevent the plurality of wear segments 4, 5 from moving in the longitudinal direction. The plurality of wear segments 4, 5 can also include projections 14, 15.

A wear segment 4 is provided for arrangement on longitudinal guiding means 6 of a roller for crushing particulate material which includes a groove 1 1 and a knob 12, wherein the groove 1 1 is configured to accept a longitudinal guiding means 6 and wherein the knob 12 is configured to extend at least partially over a portion of the guiding means 6. The wear segment 4 can also include a plurality of keyways 13, the keyways 13 cooperating with keys 10 on a roller body to prevent the wear segment 4 from moving in the longitudinal direction. The wear segment 4 can also include projections 14, 15 disposed on the knobs 12 of the longitudinal side of the wear segments 4, 5 that face the longitudinal guiding means 6 A method for manufacturing a roller 1 for crushing particulate material is also provided. The method includes the steps of: affixing a plurality of wear segments 4, 5 to a roller body 2 having a center axis 3, by arranging the wear segments 4, 5 on longitudinal guiding means 6 and disposing the wear segments 4, 5 between a plurality of clamps 7, 8; and tightening at least one of the plurality of clamps 7, 8 so that a first longitudinal side of wear segment 4 abuts guiding means 6 and a first longitudinal side of wear segment 5; a second longitudinal side of wear segment 4 abuts plurality of clamps 7 and a second longitudinal side of wear segment 5 abuts plurality of clamps 8. In some embodiments of the method, the method may also include additional steps as further described herein.

Other details, objects, and advantages of the invention will become apparent as the following description of certain present exemplary embodiments thereof and certain present exemplary methods of practicing the same proceeds. BRIEF DESCRIPTION OF DRAWINGS

Present embodiments of a roller for the crushing of particulate material are shown in the accompanying drawings. Figure 1 shows a three-dimensional model of a roller according to an exemplary embodiment of the invention.

Figure 2 shows a cross-sectional view of a roller according to an exemplary embodiment of the invention.

Figure 3 shows an exploded three dimensional view of a roller according to an exemplary embodiment of the invention.

Figure 4 shows a three-dimensional model of a roller according to another exemplary embodiment of the invention.

Figure 5 shows a cross-sectional view of a roller according to another exemplary embodiment of the invention. Figure 6 shows a bottom angled view of a wear segment according to an exemplary embodiment of the invention. Figure 7 shows a cross-sectional view of a roller according to another exemplary embodiment of the invention.

DETAILED DESCRIPTION

Referring to Figures 1 through 5, a roller 1 for crushing particulate material has a roller body 2 which has a center axis 3 extending laterally through the center shaft of the roller body 2. The outer circumference of the roller body 2 is provided with a plurality of individual wear segments 4, 5; the plurality of wear segments 4, 5 having crushing surfaces. The plurality of wear segments 4, 5 may have different crushing surfaces. For example, wear segment 5 can be made of an exotic, high end wear surface, for example a ceramic or another hard cast or forged material, without limitation; and wear segment 4 can be made of a traditional wear surface (for example, cast iron, austempered ductile iron, carbidic austempered ductile iron or polyurethane). The crushing surface of the wear segments 4, 5 may be PTA, hard-faced, sintered, hipped or may have studs (made of for example, tungsten carbide) embedded therein to increase the service life of the plurality of wear segments 4, 5.

The plurality of wear segments 4, 5 are fixed to the roller body 2. The roller has a plurality of clamps 7, 8 which are disposed on the longitudinal (i.e. - when the roller 1 is viewed in an orientation where the center axis 3 runs laterally through the center shaft of said roller body 2) sides of the roller body 2. The roller 1 has guiding means 6 disposed on the roller body 2 between the plurality of clamps 7, 8 which are disposed on the longitudinal sides of the roller body 2.

Guiding means 6 run longitudinally (i.e. - when the roller 1 is viewed in an orientation where the center axis 3 runs laterally through the center shaft of said roller body 2) (also referred to herein as "longitudinal guiding means" or simply "guiding means") about the circumference of the roller body 2.

In one embodiment, the guiding means 6 is substantially parallel to plurality of clamps 7 and plurality of clamps 8. However, the position of longitudinal guiding means 6 is determined by the regular wear pattern for a particular grinding roller application. By way of example, if the wear pattern of a grinding roller application shows that wear is greater on the left longitudinal 2/3 of the grinding roller, guiding means 6 may be disposed 2/3 from the left longitudinal side of the grinding roller. Such orientation allows for placement of high end exotic wear segments to be placed in the area where wear is the greatest and for utilization of a conventional wear segments in the remaining 1 /3. Such an arrangement allows for a uniform wear profile.

As shown in Figure 3, in one embodiment the guiding means 6 is a single uniform piece. In other embodiments the guiding means 6 are multiple pieces. Guiding means 6 are typically wedge shaped but can also be substantially rectangular in shape. Guiding means 6 may be composed of a high strength or low alloy steel, for example CrMo, without limitation. In one embodiment, the guiding means 6 is floating (i.e. - it is not affixed to the roller body 2 by a fastening means). However, as depicted in Figure 5, in another embodiment the guiding means 6 are fixed to the roller body 2 by a fastening means 9, in this case, for example, radially located screws.

In one embodiment, the roller body 2 may have two or more guiding means 6 which are disposed on the roller body 2 between the plurality of clamps 7, 8 which are disposed on the longitudinal sides of the roller body 2. Each of the two or more guiding means 6 run longitudinally (i.e. - when the roller 1 is viewed in an orientation where the center axis 3 runs laterally through the center shaft of said roller body 2) about the circumference of the roller body 2. The position of the division of the two or more guiding means 6 is determined by the regular wear pattern for the grinding roller application.

In one embodiment, one of said plurality of clamps 7 is fixed and another of said plurality of clamps 8 is movable.

The plurality of wear segments 4, 5 are arranged on longitudinal guiding means 6. When the roller has two or more guiding means 6, it is contemplated that three or more longitudinal wear segments 4, 5 can be laterally aligned, meaning that the three or more longitudinal wear segments may be fixed to the same lateral section of one lateral portion of the roller body 2. The three or more wear segments can have different wear surfaces.

Because of the longitudinal guiding means 6, the wear segments 4, 5 can be smaller and lower in weight, as opposed to if the guiding means was to run laterally. Additionally, by arranging the wear segments 4, 5 on a longitudinal guiding means 6, a longitudinal half of the wear segment (i.e. - 5) can be replaced without replacing its corresponding longitudinal half of wear segment (i.e. - 4). This arrangement is advantageous because wear profiles of certain grinding mills have shown that one longitudinal side of the roller surface wears more heavily than the other side. Such an arrangement allows the reduction of the initial costs associated with wear parts (i.e. - allowing for exotic wear parts to be used on only one longitudinal half) and allows for the amount of scrapped material to be reduced when repair is necessary. Such an arrangement promotes uniform wear across lateral subsections of the roller allowing for more efficient grinding and lower energy consumption. This arrangement also translates to less operational downtime, decreased labor costs and increased throughput.

When the plurality of wear segments 4, 5 are fixed on the roller body 2, in one embodiment, a wear segment 4 is arranged adjacent to the wear segment 5 so that when the roller body 2 is viewed so that the roller 1 is in an orientation so that the center axis 3 extends laterally through the center shaft of the roller body 2, a first long side of a wear segment 4 abuts a first long side of the wear segment 5, a second long side of the wear segment 4 abuts a clamp 7 and the second long side of the wear segment 5 abuts a clamp 8.

As may be appreciated from Figures 2, 5 and 6, in an exemplary embodiment, the plurality of wear segments 4, 5 have grooves 1 1 and knobs 12. The grooves 1 1 and knobs 12 cooperate with longitudinal guiding means 6 in order to fix the plurality of wear segments 4, 5 to the roller body 2. In an exemplary embodiment, the knob 12 of a wear segment 5 abuts the knob 12 of a wear segment 4 and the longitudinal guiding means 6 extends into the grooves 1 1 of wear segment 5 and wear segment 4.

As shown in for example Figures 2 and 3, in an exemplary embodiment, keys 10 may be disposed on the roller body 2. Keys 10 are configured to prevent longitudinal shifting of the wear segments 4, 5. In an exemplary embodiment, as shown in Figure 6, the wear segments 4, 5 have keyways 13, wherein the keys 10 interlock with the keyways 13 to further prevent the longitudinal shift of the wear segments 4, 5.

In an alternative embodiment, as shown in Figure 7, shearing pins 16 may be disposed on the roller body 2. Shearing pins 16 are configured to prevent shifting of the wear segments 4, 5. In an exemplary embodiment, as shown in Figure 7, the wear segments 4, 5 have pin holes 17, wherein the shearing pins 16 interlock with the pin holes 17 to further prevent the shift of the wear segments 4, 5. As show in Figure 6, in an exemplary embodiment, the wear segments 4, 5 have mating male projections 14 and/or female projections 15. The projections 14, 15 are disposed on the knobs 12 of the longitudinal side of the wear segments 4, 5 that face the longitudinal guiding means 6. As shown in Figures 2, 3 and 5, the wear segments 4, 5 are arranged on longitudinal guiding means 6. When all the plurality of wear segments 4, 5 are in place they are fixed to the roller body 2 by the plurality of clamps 7, 8. Fasteners, such as the axially arranged screw connections tighten the clamps 7, 8 and fix the wear segments 4, 5 to the roller body 2. For example, when the fasteners on the clamps 7, 8 are tightened, a normal force is applied to the wear segments 4, 5 and guiding means 6, the wear segments are forced against the guiding means 6 and the clamps 7, 8 and the guiding means 6 are tensioned whereby such tension and force stop the wear segments 4, 5 from further movement in the lateral direction. When the wear segments 4, 5 have mating male projections 14 and/or female projections 15 the tension and force also act to interlock the projections 14, 15 and stop the wear segments from further movement in the longitudinal direction. The guiding means 6 acts like an internal floating clamp.

In an exemplary embodiment the wear segments 4, 5 may contain knotches disposed on the longitudinal side of the wear segments 4, 5 that face the clamps 7, 8. The knotches cooperate with the clamps 7, 8 to create a tight fit and to further secure the plurality of wear segments 4, 5 to the roller body 2.

A method for manufacturing a roller 1 according to the invention is also disclosed. In an exemplary embodiment, wear segments 4, 5 are arranged on a roller body 2 on longitudinal guiding means 6 and between a plurality of clamps 7, 8. The plurality of clamps 7, 8 are tightened forcing a first longitudinal side of a wear segment 4 to abut guiding means 6 and a first longitudinal side of wear segment 5; a second longitudinal side of wear segment 4 to abut the plurality of clamps 7 and a second longitudinal side of wear segment 5 to abut plurality of clamps 8.

In another exemplary embodiment of a method for manufacturing a roller 1 according to the invention, keys 10 are fixed on the roller body and wear segments 4, 5 with keyways 13 are arranged on a roller body 2 on longitudinal guiding means 6 and between a plurality of clamps 7, 8. The plurality of clamps 7, 8 are tightened forcing a first longitudinal side of a wear segment 4 to abut guiding means 6 and a first longitudinal side of wear segment 5; a second longitudinal side of wear segment 4 to abut the plurality of clamps 7 and a second longitudinal side of wear segment 5 to abut plurality of clamps 8. When the wear segments 4, 5 have mating male projections 14 and/or female projections 15 the tightening interlocks the projections 14, 15 of a plurality of wear segments 4, 5.

It is to 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 spirit and scope of the invention as defined in the following claims.

Claims

1 . A roller (1 ) for crushing particulate material comprising:

a roller body (2) having a center axis (3);

a plurality of wear segments (4, 5) having crushing surfaces that are fixed to said roller body 2;

a plurality of clamps (7, 8) disposed on the sides of said roller body (2);

a guiding means (6) disposed on said roller body 2 between said clamps (7, 8); wherein said guiding means (6) run longitudinally about the circumference of said roller body (2) and wherein said wear segments (4, 5) are arranged on said guiding means (6) such that two or more of said wear segments (4, 5) are fixed to the same lateral section of one lateral portion of said roller body (2).

2. A roller (1 ) for crushing particulate material as in claim 1 wherein said plurality of wear segments (4, 5) are comprised of grooves (1 1 ) and knobs (12), said grooves (1 1 ) and knobs (12) cooperating with said guiding means (6) to fix said plurality of wear segments (4, 5) to said roller body (2).

3. A roller (1 ) for crushing particulate material as in claim 1 or 2 further comprising a plurality of keys (10), said plurality of keys (10) being fixed to said roller body (2).

4. A roller (1 ) for crushing particulate material as in any of the preceding claims wherein said plurality of wear segments (4, 5) are further comprised of keyways (13), said keyways (13) cooperating with said plurality of keys (10) to prevent said plurality of wear segments (4, 5) from moving in the longitudinal direction.

5. A roller (1 ) for crushing particulate material as in any of the preceding claims wherein said plurality of wear segments 4, 5 are further comprised of projections (14, 15).

6. A wear segment (4) for arrangement on longitudinal guiding means (6) of a roller for crushing particulate material comprising: a groove (1 1 ) and a knob (12), wherein said groove (1 1 ) is configured to accept a longitudinal guiding means (6) and wherein said knob (12) is configured to extend at least partially over a portion of said guiding means (6).

7. A wear segment (4) as in claim 6 further comprising a plurality of keyways (13), said keyways (13) cooperating with keys (10) on a roller body to prevent said wear segment (4) from moving in the longitudinal direction.

8. A wear segment (4) as in claim 6 or claim 7 further comprising: projections (14, 15) disposed on said knobs (12) of the longitudinal side of the wear segments (4, 5) that face the longitudinal guiding means (6).

9. A method for manufacturing a roller (1 ) for crushing particulate material, comprising the steps of: affixing a plurality of wear segments (4, 5) to a roller body (2) having a center axis (3), by arranging said wear segments (4, 5) on longitudinal guiding means (6) and disposing said wear segments (4, 5) between a plurality of clamps (7, 8) such that two or more of said wear segments (4, 5) are fixed to the same lateral section of one lateral portion of said roller body (2); and tightening at least one of said plurality of clamps (7, 8) so that a first longitudinal side of wear segment (4) abuts guiding means (6) and a first longitudinal side of wear segment (5); a second longitudinal side of wear segment (4) abuts plurality of clamps (7) and a second longitudinal side of wear segment (5) abuts plurality of clamps (8).