JPH057345U - Grinding roller for vertical mill - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent abrasion of the grinding roller. [Structure] A recess is formed in the center of the axial direction of a roller tire such as cast steel that can be easily machined. In this recess, a high-hardness wear-resistant metal material is welded up to form a welding layer. A protrusion is formed on both sides of the recess, and a thin coating layer of a wear-resistant metal material is formed on the protrusion by welding overlay, thermal spraying, Cr plating, or the like. [Effect] Since the thin coating layer is formed in the vicinity of the protruding portion of the roller tire, the coating layer is not peeled off and is not missing, and therefore the welding layer is not missing.
Therefore, it is possible to prevent the crushing ability and the crushing efficiency from decreasing, it is possible to keep the product quality good, it is possible to continue stable operation, and it is possible to extend the life of the crushing roller. Since the coating layer is thin, it does not fall off.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a grinding roller for a vertical mill.

[0002]

[Prior Art]

 FIG. 9 (1) shows a portion of a typical prior art vertical mill. A table 3 having a vertical rotation axis 2 is rotationally driven in the housing 1, and a plurality of crushing rollers 4 are pressed against the table 3 in the circumferential direction. The crushing roller 4 has a roller tire 5. A substance to be crushed is supplied onto the table 3 near the rotation axis 2 of the table 3, and the substance is crushed between the table 3 and the crushing roller 4.

FIG. 9 (2) shows the peripheral speed 6 of the table 3 and the peripheral speed 7 of the crushing roller 4 which is pressed against the table 3 and driven to rotate. Explaining the crushing mechanism of the vertical mill, as shown in Fig. 9 (2), the compression crushing mainly occurs on the center side of the table 3 due to the relative slip between the liner of the table 3 and the roller tire 5. On the nozzle 8 side radially outward, friction crushing is the main. When crushing granulated slag into fine powder, friction crushing is particularly important among compression crushing and friction crushing when finely crushing difficult-to-crush substances such as granulated slag, and this friction crushing should be performed effectively. However, this will increase the capacity of the vertical mill and improve the grinding efficiency. When the roller tire 5 of the crushing roller 4 is entirely made of the same material, the table 3 and the roller tire 5 are worn as indicated by broken lines 9 and 10 by the operation of the vertical mill. Reference numeral 11 indicates a contact center line at which the peripheral speed of the table 3 and the peripheral speed of the roller tire 5 are equal. As can be seen from the wear shapes 9 and 10, friction grinding is important in the vertical mill, and the roller tire 5 has overwhelmingly much work on the nozzle 8 side.

Here, on the nozzle 8 side, wear is less in the region having a length ΔL1 from the side portion of the roller tire 5 in the axial direction than in other regions. This is because, in this region ΔL1, although the relative slip is large, the roller pressure of the substance to be crushed is released. Also in this region ΔL1, if the region ΔL1 remains the soft metal base material, it is rapidly worn during the operation of the vertical mill. When this area ΔL1 is worn, the powder holding capacity of the crushing roller 4 on the nozzle 8 side is reduced, so that the main crushing area of FIG. 9 (1) shifts to the center of the table, and therefore the table 3 and the roller tire 5 are moved. Since the crushing diameter for crushing the material to be crushed becomes smaller and the relative sliding speed becomes smaller, both the crushing capacity and the crushing efficiency decrease rapidly. In addition, the product quality deteriorates due to the decrease in the fine powder generation capability. Therefore, sudden wear of this region ΔL1 must be avoided.

A typical prior art is shown in FIG. A welding layer 12 is formed on the entire outer peripheral surface of the roller tire 5 of the crushing roller 4 by welding buildup to improve hardness. Since the welded welded weld layer 12 is hard and brittle, and cracks are formed at intervals of about 10 mm, the weld layer 12 is likely to be missing from one side portion 13 in the axial direction of the roller tire 5, There is a problem that the welding layer 12 is missing from the vicinity of the side portion 13.

Another prior art that solves this problem is shown in FIG. 11, which is disclosed in Japanese Patent Laid-Open No. 1-26953. A welding layer 15 is formed in the recess formed in the roller tire 10 by welding overlay, and the welding layer 15 is not formed on both side portions 16 and 17, and the roller tire 14 as a base material is exposed. There is. This solves the problem that the welded welded layer 15 is likely to be missing on both sides of the roller tire 14.

[0007]

[Problems to be solved by the device]

 In the prior art shown in FIG. 11, the base material of the roller tire 14 is exposed at the side portions 16 and 17 on both sides of the high hardness welding layer 15, and the base material of the roller tire 14 is generally formed. Is a material that is unlikely to undergo thermal deformation and cracking during overlaying and is easy to machine, such as cast steel, and is easily worn. Therefore, the wear on both side portions 16 and 17 of the roller tire 14 which is originally low in abrasion is severe, the pulverizing ability is reduced, the pulverizing efficiency is reduced, the product quality is deteriorated, and the pulverized layer of the substance to be pulverized is stably formed. Not being done, vibration becomes large.

The object of the present invention is to prolong the life of the crushing roller, thereby preventing the deterioration of the crushing ability and the crushing efficiency, preventing the deterioration of the product quality, and enabling stable operation for a long time. The present invention is to provide a grinding roller for a vertical mill.

[0009]

[Means for Solving the Problems]

 According to the present invention, a roller tire is provided with a recess in the center in the axial direction, and projections are provided on both sides in the axial direction. In the recess, a wear-resistant metal material is welded up to form a welding layer. However, the crushing roller of the vertical mill is characterized in that a thin coating layer of the above-mentioned or other wear-resistant metal material is formed on the protrusion.

[0010]

[Action]

 According to the present invention, a wear-resistant metal material is weld-laid on a recess formed in the center of the roller tire in the axial direction to form a welding layer, and the object to be crushed is separated from the welding layer of the roller and the table. It enables to pulverize even if it is difficult to crush even if it is difficult to crush such as water granulated slag for a long period of time. Since a thin coating layer of a functional metal material is formed and the coating layer is formed thin as described above, it is possible to prevent the coating layer from peeling off from the protrusion of the roller tire. As a result, the abrasion resistance of the protrusions is improved, the abrasion is prevented, and the protrusions can be prevented from being lost, and the welding layer formed in the recess can be prevented from being lost. Therefore, the crushing roller can be used for a long period of time, the crushing ability and the crushing efficiency can be prevented from deteriorating, the product quality can be prevented from deteriorating, and the stable operation can be continued for a long period of time.

[0011]

【Example】

 FIG. 1 is a partially enlarged sectional view of an embodiment of the present invention. The vertical mill 20 is configured by pressing a crushing roller 24 onto a table liner 23 of a table 22 having an overhang portion 21.

FIG. 2 is a simplified sectional view of the vertical mill 20. The table 22 has a vertical rotation axis 25, and is rotationally driven by a drive source 26. A plurality of crushing rollers 24 are arranged in the circumferential direction, are pressed against the table 22 and are driven to rotate, and crush the substance to be crushed supplied near the rotation axis 25 of the table 22 between the table liner 23 and the rollers 24. Then, the pulverized substance is blown up from the nozzle 28 between the table 22 and the housing 27 by the compressed gas supplied as shown by the arrow 29, and is classified by the classifier 30 and discharged. It

The crushing mechanism of the crushing roller 20 will be described with reference to FIG. In the present embodiment, as shown in FIG. 3 (1), the table 22 is formed with the overhang portion 21 as described above, and the overhang portion 21 projects radially inward of the table 22 by the overhang amount ΔL3. ing. FIG. 3B shows the peripheral speed 32 of the table 22 and the peripheral speed 33 of the crushing roller 24. A portion where the peripheral speeds of the table 22 and the roller 24 are equal to each other is indicated by a contact center line 38. When the pressing force of the roller 24 is applied to the powder layer on the table 22, the powder layer is prevented from collapsing, and the overhang portion 21 prevents the powder layer from escaping or collapsing. The pressure exerted by the crushing roller 24 is surely transmitted to the powder layer, and the sliding force between the table 22 and the roller 24 on the nozzle 28 side can effectively act on the powder layer. There is. When the outer peripheral portion of the crushing roller 24 is made of a metal material which is easily machined as in the conventional case and thus has poor wear resistance, the table 22 and the crushing roller 24 are designated by reference numerals 34 and 35. As shown, both ends of the crushing roller 24 near the nozzle 28 are worn and rounded. As a result, the powder layer holding ability is reduced, the pulverizing ability and the pulverizing efficiency are remarkably reduced, rocking occurs, and the fine powder producing ability is reduced, resulting in poor product quality. On the other hand, in the prior art shown in FIG. 9 (1), the protrusion remains, and the region ΔL1 has a size of 10 to 50 mm, for example. By providing the overhang portion 21, the crushing area of the powder layer moves radially outward, and the maximum wear portion, and thus the main crushing area, is as indicated by the reference numeral 36, and shifts significantly toward the overhang portion 21. However, the crushing capacity and the crushing efficiency are significantly improved.

In the vertical mill 20 having the above-mentioned overhang portion 21, in particular, the overhang portion 21 locally forms the grinding region on the side of the roller 24 near the overhang portion 21, so that the grinding roller 24 When the side portion 37 close to the overhang portion 21 is worn, the influence thereof is extremely large as compared with the above-mentioned prior art. Specifically, when the side portion 37 of the crushing roller 24 is worn, the crushing ability and the crushing efficiency are significantly reduced, and when the amount of wear is increased, the stabilization of the crushing layer begins to deteriorate, and vibration is generated. The fine powder generation ability is reduced and the product quality is reduced.

In particular, in the vertical mill 20 having the overhang portion 21, the main crushing area shifts to the dam side, so that the area ΔL2 of the side portion 37 of the crushing roller 24 becomes small, so that the side portion 37 is worn. It is easy to do, and its wear has a great influence on the performance of the vertical mill. Therefore, it is very important to take measures against the wear of the side portion 37.

Referring again to FIG. 1, the crushing roller 24 according to the present invention comprises a roller tire 41 made of a metal material which is sticky and easy to machine, and which has a bearing 42 as shown in FIG. The roller tire 41 is rotatably supported. A recess 44 is formed in the center of the roller tire 41 in the direction of the axis 43, a protrusion 45 is formed on one side 31 of the roller tire 41, and a protrusion 45 is formed on the other end. The protrusion 46 is formed. In the recess 44, a wear resistant metal material is welded up to form a welding layer 47. Further, thin coating layers 48 and 49 of wear-resistant metal material are formed from the welding layer 47 to the vicinity of the projections 45 and 46. The metal material as the base material of the roller tire 41 is preferably cast steel (SC), cast iron (FC), ductile cast iron (FCD), forged steel (SF), or the like. As the wear-resistant metal material for welding and forming the weld layer 47, carbon 3 to 7% and chromium 20 to 30% are the basic components, and manganese 1 to 4% and silicon 0.5 to 2 are added. %, And 0 to 2% of molybdenum, zircon, titanium or the like is further added. The thickness of the welding layer 47, that is, the depth h1 of the recess 44 is, for example, 15 to 40 mm, and preferably 20 to 30 mm. This welding layer is formed of, for example, 7 to 20 layers as shown in an enlarged view in FIG. 4, and the height h 3 of each layer is 1 to 3 mm, generally about 2 mm. In FIG. 4, the weld bead is designated by reference numeral 52. The width w1 of the welding beat 52 is, for example, 3 to 5 mm. In the weld layer 47, the weld overlay metal has a high hardness and is prone to generate cracks 47a, which can prevent residual thermal stress from remaining in the roller tire 41 as the base material.

The coating layer 48 may be formed by welding and overlaying the same metal material as that of the welding layer 47, and in this case, the thickness h2 thereof is, for example, 5 to 6 mm or less. Such a coating layer 48 can be achieved by forming a few weld overlays of metal. Where the build-up layer is thin, such as a few layers or less, the coating layer 48 is welded to the protrusions 45 of the roller tire 41 so that the metal material forming the coating layer 48 and the metal of the roller tire 41 are separated from each other. When they penetrate into each other, they become an alloy, and the amounts of C, Cr, etc. are reduced in the areas where they have penetrated, and the adhesion strength of the coating layer 48 can be increased. The coating layer 48 may be made of the same metal material as that of the above-mentioned welding layer 47, but may be made of a hard material having stickiness and having less carbon content so that cracks are less likely to occur. The same applies to the coating layer 49. The coating layers 48, 49 may be formed by thermal spraying, and the thickness h2 of the coating layers 48, 49 by thermal spraying is, for example, about 0.5 to 5 mm, and the material is Cr, WC or the like. Further, as a material, SUS420J 2 containing 13.5% Cr may be sprayed to obtain a hardness of about Hs45. Furthermore, Ni-based alloy MSF Ni may be used, which contains 15 to 20% of Cr and can obtain hardness HRc55 to 65. Further, the coating layer 48 may be formed by Cr plating.

In FIG. 1, if the roller tire and the table liner are all made of the same material, the wear that occurs on the crushing roller 4 and the table 22 during operation of the vertical mill 20 is indicated by broken lines 54 and 55.

The length L0 of the coating layer 48 in the axial direction along the peripheral surface of the crushing roller 24 is, for example, 10 to 50 mm, preferably 20 to 30 mm, and more preferably 20 mm. The circumferential length L1 of the welding layer 47 in the crushing roller 4 is 900 mm, for example. The outer diameter of the roller 22 is, for example, 2 m.

In this way, the protrusions 45 and 46 are provided on both sides of the roller tire 41, and the coating layers 48 and 49 for improving wear resistance are thinly formed on the surfaces of the protrusions 45 and 46, respectively. By doing so, it is possible to prevent the coating layers 48, 49 from being peeled off or missing from the protrusions 45, 46. Since the pressing force of the crushing roller 4 is released in the vicinity of the protrusions 45, 46, no large wear occurs in the vicinity of the coating layers 48, 49. Therefore, even if the coating layers 48 and 49 are thin, the life is sufficiently long, and the thin coating layers 48 and 49 improve the adhesion strength with the protrusions 45 and 46 as described above. become. In this way, the roller tire 41 not only allows the use of a metal material that is easy to machine and is inexpensive, but such a metal material is sticky, and there is little concern about cracks due to hardfacing, and possible repeated overlaying. The number of times is significantly increased, the life of the roller tire 41 as a base material is significantly extended, and thus the cost can be reduced.

FIG. 5 is a sectional view of a part of the crushing roller 24 according to another embodiment of the present invention. On the roller tire 41, a wear-resistant metal material is welded up to form welding layers 57 and 58. In view of the tendency of the surface of the crushing roller 24 to wear as shown by reference numeral 54 in FIG. 1, the welding layers 57 and 58 are formed in the central recess of the roller tire 41 in the same manner as described above. When the thickness h4 of the central portion is reduced and the thicknesses h5 and h6 (h5 = h6) on both sides are increased and one of the welding layers 57 is worn, the roller tire 41 is moved from the bearing 42 of FIG. It is detached and mounted in such a manner that the axial direction is reversed and the welding layer 58 is used for pulverization. In this way, the grinding roller 24 can be used for a long period of time. The ends of the welding layers 57 and 58 may have an angle θ1 of 5 to 10 ° with respect to a line perpendicular to the axis 43 of the crushing roller 24.

FIG. 6 is a partial cross-sectional view of another embodiment of the present invention. This embodiment is similar to the previous embodiment, and the corresponding parts bear the same reference numerals. It should be noted that in this embodiment, a thin coating layer 48 near the protrusions 45 of the grinding roller 24 is formed on the side surface 60 of the roller tire 41, extending radially W2 as indicated by reference numeral 61. To be done. As a result, abrasion of the protrusion 45 can be prevented more reliably. The same applies to the other coating layer 49.

The present invention can also be implemented for a vertical mill in which the overhang portion 21 is not used. Further, as shown in FIGS. 7 and 8, the surface of the thin coating layer 48 and the surface of the welding layer 47 may be the same continuous surface.

[0024]

[Effect of the device]

 As described above, according to the present invention, a wear-resistant metal material is welded and built up in a recess formed in the center of a roller tire to form a welding layer, and projections are formed on both sides of the welding layer. Since a thin coating layer of wear-resistant metal material is formed near the protrusion, the protrusion is not missing.Because the coating layer is also thin, it is unlikely to peel off from the vicinity of the protrusion and therefore the recess It is also possible to prevent the welding layer from missing. As a result, it is possible to prevent the vertical mill's crushing ability from deteriorating, judge crushing for a long time and continue, and prevent vibration from occurring, thus maintaining high crushing efficiency for a long time. .. In addition, it is possible to prevent deterioration of the fine powder generation ability and prevent deterioration of product quality. In this way, the roller tire can be used for a long period of time and its life can be extended.

Further, according to the present invention, an inexpensive metal material can be used as the base material of the roller tire on which the welding layer and the coating layer are to be formed, and the cost can be reduced. Such a metal material as the base material of the roller tire is generally easy to machine, and there is little fear of the base material cracking due to repeated buildup, and the number of times of repeated use can be improved. Further, such a base material is easy to machine as described above, and moreover, it is possible to easily carry out the weld overlay for forming the welding layer, and therefore, it is possible to easily manufacture a new crushing roller. At the same time, it becomes easy to perform the overlaying again when the welding layer is worn. Further, according to the present invention, since the coating layer is formed on the protruding portion of the roller tire, the protruding portion is not worn, so that a stable buildup can be obtained every time the welding layer is worn. It can be repeated many times, and repair overlaying can be easily performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a table 22 and a crushing roller 24 according to an embodiment of the present invention.

FIG. 2 is a simplified sectional view of the entire vertical mill 20.

FIG. 3 is a view showing a crushing mechanism by a table 22 and a crushing roller 24.

FIG. 4 is a partial enlarged cross-sectional view showing a state of the welded portion 47 during manufacturing.

FIG. 5 is a sectional view of a crushing roller according to another embodiment of the present invention.

FIG. 6 is a sectional view of a crushing roller 24 according to still another embodiment of the present invention.

FIG. 7 is a partial cross-sectional view of another embodiment of the present invention.

FIG. 8 is a partial cross-sectional view of still another embodiment of the present invention.

FIG. 9 is a view showing a crushing mechanism by a table 3 and a crushing roller 4 according to the prior art.

FIG. 10 is a cross-sectional view of a prior art grinding roller 4.

FIG. 11 is a cross-sectional view of another prior art grinding roller 4.

[Explanation of symbols]

 21 Overhang Part 22 Roller 23 Table Liner 24 Grinding Roller 41 Roller Tire 44 Recess 45,46 Projection 47 Welding Part 48,49 Coating Layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Hashimoto 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe City Kawasaki Saki Heavy Industries, Ltd. Kobe factory (72) Inventor Susumu Uchiyama 3-chome, Higashikawasaki-cho, Chuo-ku, Kobe No. 1 Kawasaki Heavy Industries Co., Ltd. Kobe factory (72) Inventor Junji Suetsugu 3 Hikari, Kashima-cho, Kashima-machi, Kashima-gun, Ibaraki Prefecture Sumitomo Metal Industries, Ltd. Kashima Works (72) Inventor Susumu Tomita Kashima-machi, Kashima-gun, Ibaraki Prefecture Sumikin Kashima Mineralization Co., Ltd. (72) Inventor Tomoki Miyata Kajima-cho, Kashima-gun, Ibaraki Prefectural Sumikin Kashima Mineralization Co., Ltd.

Claims (1)

[Claims for utility model registration] Claims: 1. A roller tire is provided with a recess at the center in the axial direction, and projections are provided at both sides in the axial direction. A grinding roller for a vertical mill, characterized in that a welding layer is formed by welding to build up a welding layer, and a thin coating layer of the above-mentioned or other wear-resistant metal material is formed on the protrusion.