JP2016179428A - Pulverizing roller for vertical mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulverizing roller for a vertical mill capable of improving the wear resistance of a roller part and reducing a repair cost.SOLUTION: A pulverizing roller 16 for rotatably rolling on a turntable through a pulverizing material thereby to pulverize said pulverizing material, comprises: a boss 18 of a truncated conical shape; and a roller part 50 of a truncated conical shape fitting along the outer circumference of said boss 18. The pulverizing roller 16 is characterized in that said roller part 50 is divided into plural parts in the axial direction thereby to perform a heat treatment according to the individual split capacities of the rollers.SELECTED DRAWING: Figure 1

Description

  The present invention mainly pulverizes coal, oil coke, limestone, slag, clinker, cement raw material, other inorganic raw materials, or organic raw materials such as chemicals and biomass into powder with a crushing roller driven on a rotary table. The present invention relates to a crushing roller of a vertical crusher.

  A vertical crusher is widely used as a crusher for crushing raw materials such as coal and biomass. A conventional vertical crusher includes a rotary table and a plurality of crushing rollers arranged in a position that equally divides the outer peripheral portion of the upper surface of the rotary table in the circumferential direction in a casing that forms an outer shell of the crusher. .

  In such a vertical crusher, when the pulverized raw material is supplied to the center of the rotary table, the pulverized raw material moves to the outer peripheral portion of the rotary table by the rotation of the rotary table. Since the crushing roller is pressed against the outer peripheral portion and rotated, the crushing raw material enters between the crushing roller and the rotary table and is crushed. And by the hot air blowing from the annular passage between the outer peripheral surface of the rotary table and the inner peripheral surface of the casing, the inside of the casing rises while the granular material is dried together with the hot air. The powder particles are sorted by the classifying means provided in the upper part of the casing, and the product of a predetermined particle size is discharged to the outside. Coarse powder that cannot pass through the classification means falls again on the rotary table and is pulverized.

The crushing rollers of the vertical crusher include those formed in a truncated cone shape in addition to those formed in an annular shape. A general crushing roller is configured by fitting a ring-shaped roller portion to a roller shaft. Since the grinding roller is worn out by the grinding operation, the ring-shaped roller portion is periodically replaced. In order to reduce the number of times the roller part is replaced, a high chromium material is cast on the crushing surface that contacts the pulverized material at the base of the ductile member FCD (spherical graphite cast iron). A composite material is used (for example, disclosed in Patent Document 1), and a ceramic material is disposed on the surface of the roller portion for the purpose of obtaining wear resistance (for example, disclosed in Patent Document 2).
In addition, a roller surface is formed on the base of the FCD of the ductile member by high hardness hard welding to obtain wear resistance (for example, disclosed in Patent Document 3). Measures have been implemented to arrange materials with high hardness.

Registered Utility Model No. 2536282 JP 2009-183877 A JP 2007-216101 A

  However, the method of increasing the hardness of the roller surface in contact with the pulverized material common to these can improve the wear resistance, but has a demerit that the cracking sensitivity increases due to a decrease in the ductility of the material. The crushing roller is exposed to harsh conditions under severe impact during crushing. The minute cracks generated on the roller surface by the impact load develop into large cracks due to repeated motion of the impact, and the roller finally breaks. There is an example in which a layer of stainless steel with high ductility is formed by welding between a part with high hardness and a base material so that cracks do not reach the base material of the roller part, but a roller like a grinding roller of a vertical crusher When tension repeatedly acts on the surface (Hertz contact stress), it is difficult to stop the progress of cracks, and therefore, parts were regularly replaced before the cracks became large.

  In view of the above-described problems of the conventional technology, an object of the present invention is to provide a crushing roller for a vertical crusher that can improve the wear resistance of the roller portion and reduce the repair cost.

As a first means for solving the above-mentioned problems, the present invention provides a grinding roller of a vertical crusher that rolls in a freely rotating manner in contact with a grinding table via a grinding material, and crushes the grinding material. The crushing roller is composed of a frustoconical boss and a frustoconical roller portion that fits along the outer periphery of the boss, and the roller portion is divided into a plurality of parts in the axial direction. An object of the present invention is to provide a crushing roller for a vertical crusher characterized by performing heat treatment according to the volume.
With such a configuration, since the roller portion is divided into a plurality of parts in the axial direction, an optimum heat treatment corresponding to each divided volume (cross-sectional capacity) can be performed for each roller. Accordingly, it becomes easy to obtain a target hardness of the entire roller portion. Further, it is possible to suppress deformation of the heat treatment due to the difference in cross-sectional capacity generated in the integrated structure.

According to the present invention, as a second means for solving the above-described problem, in the first means, the roller portion determines the number of divisions according to the size of the worn portion or the size of the grinding roller. It is an object of the present invention to provide a crushing roller for a vertical crusher.
By adopting such a configuration, machining or handling is facilitated by dividing the roller size into a plurality of blocks in the axial direction of the roller portion and making the roller size small. Further, even when a crack is generated from the surface of the roller portion, it is accommodated within the block range, and the entire roller portion is not damaged. In addition, the repair cost can be reduced by replacing only cracked or worn blocks.

According to the present invention, as a third means for solving the above-described problem, in the first or second means, the roller portion is formed by combining high chromium steel having different hardness or hardfacing welding. It is an object of the present invention to provide a crushing roller for a vertical crusher characterized by the above.
By adopting such a configuration, a different material can be used for each roller obtained by dividing the roller portion into a plurality of portions in the axial direction, and the wear resistance of the roller portion can be improved.

  According to the present invention as described above, since the roller portion is divided into a plurality of parts in the axial direction, it is possible to perform an optimum heat treatment according to each divided volume (cross-sectional capacity) for each roller. Accordingly, it becomes easy to obtain a target hardness of the entire roller portion. Further, the deformation of the heat treatment due to the difference in cross-sectional capacity generated in the integral structure is reduced.

It is explanatory drawing of the crushing roller of the vertical crusher of this embodiment. It is a block schematic diagram of a vertical crusher.

  Embodiments of a crushing roller of a vertical crusher of the present invention will be described below in detail with reference to the accompanying drawings.

[Vertical crusher 10]
FIG. 2 is a schematic diagram of the configuration of the vertical crusher. In FIG. 2, the detailed configuration of the crushing roller 16 is omitted. As shown in FIG. 2, the vertical crusher 10 includes a casing 12, a rotating table 14, a plurality of crushing rollers 16 arranged at positions where the outer peripheral portion of the upper surface of the rotating table 14 is equally divided in the circumferential direction, An annular passage 40 formed along the outer periphery of the table 14, classification means 30 provided on the upper portion of the casing 12, and a dam ring 48 attached on the outer peripheral edge of the rotary table 14 are the main basic components.

  The crushing roller 16 is connected to the piston rod of the hydraulic cylinder 24 via an upper arm 20 pivotally attached to the lower casing 12B serving as a fulcrum and a lower arm 22 formed integrally with the upper arm 20. . The crushing roller 16 is laterally pressed on the upper surface 14A of the rotary table by the operation of the hydraulic cylinder 24, and rotates by being driven by the rotary table 14 via the crushing raw material.

A classification means 30 is provided above the upper surface 14 </ b> A of the casing 12.
The classifying means 30 includes a rotary shaft 30a, a rotary blade 30b, and a fixed blade 30c. The rotating shaft 30a hangs downward from the upper surface of the casing 12, and is configured to be rotatable by an external drive motor (not shown). A plurality of rotary blades 30b are arranged in a ring shape below the rotary shaft 30a, with the rotary shaft 30a as an axis. Further, a plurality of fixed blades 30c are formed side by side on the outer periphery of the rotary blade 30b. Both the rotary blade 30b and the fixed blade 30c are arranged in parallel with the axis of the rotary shaft 30a in the longitudinal direction, and the hot air rising in the casing 12 is a gap between the blades parallel to the axis of the rotary shaft 30a. Supplied from In the classifying means 30 having such a configuration, the rotary blade 30 b rotates together with the rotary shaft 30 a, and only fine powder particles (fine powder) that have passed through the fixed blade 30 c and the rotary blade 30 b are discharged from the upper outlet 44.

  An inner cone 30e and a feed pipe 30f are provided at the lower end of the fixed blade 30c. The inner cone 30e is formed in a funnel shape whose diameter decreases from the upper side to the lower side, and the feed tube 30f is formed in a cylindrical shape connected to the lower end of the inner cone 30e. The body is captured and supplied to the rotary table upper surface 14A from the lower discharge port via the feed tube 30f.

A raw material charging chute 34 is connected to the inner cone 30e. The raw material is charged from the raw material charging port 32 to the rotary table upper surface 14A via the raw material charging chute 34.
The raw material charged from the raw material charging chute 34 moves to the outer periphery of the rotary table upper surface 14A while drawing a spiral trajectory on the rotary table upper surface 14A, and is caught between the rotary table upper surface 14A and the grinding roller 16 and pulverized. The A part of the pulverized granular material passes over the dam ring 48 that is provided around the outer edge of the turntable upper surface 14A to adjust the layer thickness of the raw material, and the outer periphery of the turntable upper surface 14A and the casing 12 It goes to the annular passage 40 which is a gap. Here, a gas introduction port 42 for introducing hot air heated to a predetermined temperature is provided below the turntable 14 of the lower casing 12B.

During operation of the vertical crusher 10, by introducing hot air from the gas inlet 42, the hot air flowing through the classification means 30 from below the rotary table 14 to the upper outlet 44 in the casing 12. Airflow is generated.
The raw material charged into the vertical crusher 10 and part of the powder that has been crushed by the rotary table 14 and the crushing roller 16 and overcame the dam ring 48 described later are blown up by hot air from the annular passage 40. The inside of the casing 12 is raised and reaches the classifying means 30.

Here, the granular material having a large diameter and mass cannot pass through the fixed blade 30c and the rotating blade 30b of the classifying means 30, falls to the internal cone 30e, is re-engaged by the grinding roller 16, and is crushed. The On the other hand, the granular material having a small diameter passes through the classifying means 30 through the fixed blades 30c and the rotary blades 30b arranged with a gap therebetween, and is taken out of the casing 12 through the upper outlet 44.
Further, a part of the raw material having a maximum particle size that has reached the annular passage 40 without being caught by the grinding roller 16 falls below the rotary table 14 from the annular passage 40 and is vertically crushed from the lower outlet 46. It is taken out of the machine 10.

[Crushing roller 16]
FIG. 1 is an explanatory view of a crushing roller of the vertical crusher of this embodiment. As shown in the figure, the grinding roller 16 employs a configuration in which a boss 18 and a roller portion 50 are slidably attached to a roller shaft 16 a via a bearing 17.
The roller portion 50 is formed in a truncated truncated cone shape that fits along the outer periphery of the truncated cone-shaped boss 18. The roller part 50 is divided into a plurality of parts in the axial direction. As an example, the roller unit 50 of the present embodiment employs a three-part structure of first to third rollers 52, 54, and 56 from the large diameter side to the small diameter side. The number of divisions of the roller portion 50 can be arbitrarily changed according to the size of the worn portion or the size of the grinding roller 16, so that the deformation of the heat treatment due to the difference in cross-sectional area is reduced. The first to third rollers 52, 54, and 56 are coupled to each other along the axial direction of the roller shaft 16a using, for example, fastening means (not shown). The first to third rollers 52, 54, and 56 have different divided volumes (cross-sectional capacities). In general, the grinding roller 16 is more easily worn on the larger diameter side than on the smaller diameter side. Therefore, in the first to third rollers 52, 54, and 56 of the present embodiment, the first roller 52 is more than the third roller 56. Wear is severe.

  Such a roller part 50 can use cast steel, cast iron, high chromium steel for a material, can use high chromium steel from which hardness differs, or can combine hardening overlay welding. The first to third rollers 52, 54, 56 are made of the same material, or only the first roller 52 on the large diameter side is made of a material having high wear resistance, so that the second and third rollers 54, 56 are made. Different materials can be used. As an example, when increasing the hardness of the first roller 52 on the large diameter side, the material is made to contain chromium, tungsten, or the like.

  Further, the grinding roller 16 is quenched according to each divided volume (cross-sectional capacity) for each of the first to third rollers 52, 54, 56 before the first to third rollers 52, 54, 56 are coupled to each other. The heat treatment is performed. This heat treatment can be performed as follows, for example. The hardness of the first roller 52 on the large diameter side can be increased by performing the cooling time in a short time, and the hardness of the third roller 56 on the small diameter side can be changed by performing the cooling time slowly. Thereby, the deformation | transformation resulting from the difference in the cooling temperature by the difference in the cross-sectional area of the large diameter side and small diameter side which arises with the conventional integral structure can be suppressed. In addition, compared with the conventional integral-structure roller unit, the block-formed roller unit 50 according to the present embodiment can reduce the size of the heat treatment apparatus and can be easily handled.

[Action]
The operation of the crushing roller of the vertical crusher of the present invention having the above configuration will be described below.

When the rotary table 14 of the vertical crusher 10 is rotated, the crushing roller 16 laterally pressed by the hydraulic cylinder 24 onto the upper surface 14A of the rotary table is also rotated. Then, when the pulverized raw material is charged from the raw material charging port 32 to the rotary table upper surface 14A, it falls onto the rotary table upper surface 14A and moves to the outer periphery of the table while drawing a spiral trajectory on the rotary table upper surface 14A. The table upper surface 14A and the crushing roller 16 are caught and crushed.
The crushing roller 16 has a predetermined hardness because the first to third rollers 52, 54, and 56 are appropriately heat-treated according to each divided volume. Therefore, even the first roller 52 on the large-diameter side, which is heavily worn, has improved wear resistance performance and can extend the life of the entire apparatus.

According to the pulverization roller of the vertical pulverizer of the present invention, it is possible to perform an optimum heat treatment according to each divided volume (cross-sectional capacity) for each roller. Accordingly, it becomes easy to obtain a target hardness of the entire roller portion. By increasing the hardness of only the roller surface as in the prior art, micro cracks are likely to occur due to a decrease in the ductility of the surface material, and there is no possibility that the roller will suddenly break due to long-term operation of the device and suddenly stop.
Further, even if a crack occurs from the surface of the roller portion, it falls within the range of the corresponding block and does not lead to damage of the entire roller portion.

  The present invention is particularly useful for a vertical crusher that crushes raw materials such as coal and biomass with a crushing roller driven by rotation of a rotary table.

DESCRIPTION OF SYMBOLS 10 ......... Vertical crusher, 12 ......... Casing, 12B ......... Lower casing, 14 ......... Rotary table, 14A ......... Rotary table upper surface, 16 ......... Crushing roller, 16a ......... Roller shaft 17 ......... Bearings, 18 ......... Boss, 20 ......... Upper arm, 22 ......... Lower arm, 24 ......... Hydraulic cylinder, 30 ......... Classifying means, 30a ......... Rotating shaft, 30b ... ...... Rotating blade, 30c ......... fixed blade, 30e ......... inner cone, 30f ......... feed pipe, 32 ...... raw material charging port, 34 ......... raw material charging chute, 40 ...... annular passage, 42 ......... Gas inlet, 44 ......... Upper outlet, 48 ......... Dam ring, 50 ......... Roller part, 52 ...... First roller, 54 ......... Second roller, 56 ......... No. 3 rollers.

Claims (3)

In a crushing roller of a vertical crusher that rolls freely in contact with a rotating table via a crushing raw material and crushes the crushing raw material,
The crushing roller is composed of a frustoconical boss and a frustoconical roller portion fitted along the outer periphery of the boss,
The roller part is divided into a plurality of parts in the axial direction, and heat treatment is performed according to each divided volume of the roller.   2. The crushing roller of a vertical crusher according to claim 1, wherein the roller unit determines the number of divisions according to the size of a wear portion or the size of the crushing roller.   The crushing roller of a vertical crusher according to claim 1 or 2, wherein the roller part is formed by combining high chromium steels having different hardness or hardfacing welding.

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