Crushing roller, solid fuel crushing device, and method of manufacturing the crushing roller

Abstract

To suppress abrasion of a roller part when being used in a state where the roller part is reversed, and lengthen a life of a roller part.SOLUTION: A crushing roller comprises: a toric roller part 49 which is engaged with an outer periphery part of a journal housing from outside and crushes a solid fuel between a crushing table and the crushing roller. The roller part 49 includes: a first part 49A; and a second part 49B which is arranged with the first part 49A in a line along an axial direction and fixed to the first part 49A. The first part 49A includes: a first proximal part 51A which is engaged with the outer periphery part of the journal housing from outside; and a first ceramic part 52A which is arranged on the outer periphery surface of the first proximal part 51A and excellent in abrasion resistance compared with the first proximal part 51A. The second part 49B includes: a second proximal part 51B which is engaged with the outer periphery part of the journal housing from outside; and a second ceramic part 52B which is arranged on the outer periphery surface of the second proximal part 51B and excellent in abrasion resistance compared with the second proximal part 51B.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a grinding roller, a solid fuel grinding device, and a method for manufacturing a grinding roller. [Background technology]

[0002] Conventionally, solid fuels such as biomass fuels and coal are pulverized into fine powder within a predetermined particle size range in a pulverizer (mill) and then supplied to a combustion device. In the mill, the solid fuel fed onto a pulverizing table is pinched between the pulverizing table and a pulverizing roller to pulverize it. The pulverized solid fuel is then sorted using a classifier to select fine particles within a predetermined particle size range. The fine particles are then transported to a boiler by a carrier gas (primary air) supplied from the periphery of the pulverizing table, where they are combusted in the combustion device. In a thermal power plant, steam is generated by heat exchange with the combustion gas produced by burning the pulverized fuel in the boiler. This steam drives a steam turbine, which in turn drives a generator connected to the steam turbine, thereby generating electricity.

[0003] Such mills are disclosed, for example, in US Pat. No. 5,629,991 and US Pat. No. 5,629,991. Patent Document 1 discloses a mill equipped with a grinding roller having a base made of high chromium cast iron that fits into a journal housing and a hardened portion that includes a ceramic member provided on the outer peripheral surface of the base.

[0004] Patent Document 2 discloses a vertical mill equipped with a table having a rotation axis extending vertically and a plurality of rollers arranged on the upper surface of the table. The roller device includes a mounting member rotatably attached to a support shaft via a bearing that receives radial force, a first segment smoothly attached to the outer circumferential surface in the radial direction with respect to the axis of the support shaft of the mounting member and having a tapered surface that tapers radially outward from the table, and a second segment having a tapered surface shaped to match the tapered surface of the first segment. The first and second segments are fixed to the mounting member with mounting bolts and integrally form a roller. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-11164 [Patent Document 2] Japanese Patent Application Publication No. 62-204862 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, there are grinding rollers provided in mills that have ceramic-embedded rollers in which highly wear-resistant ceramics are embedded in the outer periphery of the base of the grinding roller at the portion that comes into contact with the solid fuel. These ceramic-embedded grinding rollers have superior wear resistance and allowable wear amount compared to conventional grinding rollers, and can be expected to have a longer lifespan.

[0007] Due to manufacturing reasons, ceramic-embedded grinding rollers have a problem in that the ceramic portion cannot be arranged symmetrically with respect to a plane perpendicular to the direction of the roller's rotation axis. For this reason, ceramic-embedded grinding rollers, like the roller described in Patent Document 1, have had their ceramic portion arranged offset to one side in the direction of the roller's rotation axis. This problem will be explained in detail. When manufacturing a ceramic-embedded grinding roller, first, a ceramic block is placed in a predetermined position in the mold, and molten metal is poured into the mold. The metal in the mold is then cooled and solidified. In this way, a ceramic-embedded grinding roller is manufactured, in which the ceramic portion (the portion containing the ceramic) and the base portion (the portion not containing the ceramic) are integrally fixed. Because the ceramic portion has a lower specific gravity than the molten metal, it is subjected to buoyancy in the molten metal when the roller is cast. During casting, this buoyancy is used to press the ceramic portion into a predetermined position on the top of the mold and fix it in place. At this time, it is necessary to shift the center of buoyancy of the ceramic portion to one side of the roller (e.g., the outer periphery) to prevent the ceramic portion from tipping over to the other side (e.g., the inner periphery) during casting. Therefore, even after completion, the ceramic portion will be biased to one side. For these reasons, it has been difficult to symmetrically arrange the ceramic portion of a ceramic-embedded roller.

[0008] However, the wear of the crushing roller may occur more on one side than on the other side in the direction of the roller's rotation axis. Therefore, even if one side of the crushing roller is worn, the other side may not be worn as much. In such cases, the crushing roller may be used in an inverted state. That is, the roller unit may be removed, turned over so that one side is reversed, and then reattached for use.

[0009] When a crushing roller is used in a reversed state, if the ceramic portion is biased to one side as in the crushing roller described in Patent Document 1, the solid fuel will be crushed in the portion where the ceramic portion is not provided after the roller is reversed. This makes it easier for wear to progress after the roller is reversed, potentially shortening the life of the crushing roller.

[0010] Patent Document 2 describes a roller in which a first segment and a second segment are integrated by fastening them together with bolts. However, the roller described in Patent Document 2 is not a ceramic-embedded roller. For this reason, Patent Document 2 does not take into consideration the possibility of constructing a roller by integrating multiple components in a ceramic-embedded roller.

[0011] The present disclosure has been made in consideration of the above circumstances, and aims to provide a crushing roller, a solid fuel crushing device, and a method for manufacturing a crushing roller that can suppress wear on the roller part and extend the life of the roller part even when the roller part is used in an inverted position. [Means for solving the problem]

[0012] In order to solve the above problems, the crushing roller, solid fuel crushing device, and crushing roller manufacturing method of the present disclosure employ the following measures. A crushing roller according to one aspect of the present disclosure is a crushing roller that is housed inside a housing, crushes solid fuel by sandwiching the solid fuel between itself and a rotating crushing table, and rotates by receiving rotational force from the crushing table, and includes: a support portion that is rotatably supported by the housing around a central axis; and an annular roller portion that fits externally around the outer periphery of the support portion and crushes the solid fuel between itself and the crushing table, the roller portion having a first portion and a second portion that is fixed to the first portion and is arranged alongside the first portion along an axial direction that is the direction in which the central axis of rotation of the roller portion extends; The outer circumferential surface is curved to be arc-shaped in a cross section in the axial direction, The first portion includes a first base portion that fits onto the outer periphery of the support portion from the outside, and a first base portion that fits onto the outer periphery of the first base portion. Integral with the first base a first outer peripheral portion having superior wear resistance to the first base portion, and the second portion is provided on one side of the center line in the axial direction, and the second portion is provided on the outer peripheral surface of the second base portion, the second base portion being fitted to the outer peripheral portion of the support portion from the outside. Integral with the second base a second outer peripheral portion provided on the other side of the center line in the axial direction and having superior wear resistance to the second base portion; The first outer peripheral portion and the second outer peripheral portion are provided so as to be line-symmetrical with respect to the center line in a cross section in the axial direction. do.

[0013] A method for manufacturing a crushing roller according to one aspect of the present disclosure is a method for manufacturing a crushing roller that is housed inside a housing, crushes solid fuel by sandwiching it between itself and a rotating crushing table, and rotates with the rotational force from the crushing table, wherein the crushing roller comprises a support portion that is supported rotatably about a central axis relative to the housing, and an annular roller portion that fits externally around the outer periphery of the support portion and crushes the solid fuel between itself and the crushing table, and the roller portion has a first portion and a second portion that is fixed to the first portion and is arranged alongside the first portion along an axial direction that is a direction in which the central axis of rotation of the roller portion extends, The outer circumferential surface is curved to be arc-shaped in a cross section in the axial direction, The first portion includes a first base portion that fits onto the outer periphery of the support portion from the outside, and a first base portion that fits onto the outer periphery of the first base portion. Integral with the first base a first outer peripheral portion having superior wear resistance to the first base portion, and the second portion is provided on one side of the center line in the axial direction, and the second portion is provided on the outer peripheral surface of the second base portion, the second base portion being fitted to the outer peripheral portion of the support portion from the outside. Integral with the second base a second outer peripheral portion having superior wear resistance to the second base portion, the second outer peripheral portion being provided on the other side of the center line in the axial direction, the first outer peripheral portion and the second outer peripheral portion are provided so as to be line-symmetrical with respect to the center line in a cross section in the axial direction, The method includes the steps of manufacturing the first portion, manufacturing the second portion, and fixing the first portion and the second portion together. [Effects of the Invention]

[0014] According to the present disclosure, even when the roller unit is used in an inverted state, wear on the roller unit can be suppressed, and the life of the roller unit can be extended. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a configuration diagram showing a solid fuel pulverizer and a boiler according to an embodiment of the present disclosure. FIG. [Figure 2] FIG. 2 is a schematic side view of a pulverizing roller provided in the solid fuel pulverizing device according to the embodiment of the present disclosure. [Figure 3] FIG. 2 is a cross-sectional view of a main portion of a crushing roller according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a schematic diagram illustrating a mold for manufacturing a crushing roller according to an embodiment of the present disclosure. [Figure 5] FIG. 10 is a schematic diagram showing a mold for manufacturing a crushing roller according to a modified example of an embodiment of the present disclosure. [Figure 6] FIG. 10 is a cross-sectional view of a main portion of a crushing roller according to a modified example of an embodiment of the present disclosure. [Figure 7] FIG. 10 is a cross-sectional view of a main portion of a crushing roller according to a modified example of an embodiment of the present disclosure. [Figure 8] FIG. 10 is a cross-sectional view of a main portion of a crushing roller according to a modified example of an embodiment of the present disclosure. [Figure 9] FIG. 10 is a cross-sectional view of a main portion of a crushing roller according to a modified example of an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a crushing roller, a fixed fuel crushing device, and a method for manufacturing a crushing roller according to the present disclosure will be described below with reference to the accompanying drawings.

[0017] The power plant 1 according to this embodiment includes a solid fuel pulverizer 100 and a boiler 200. In the following explanation, "upper" refers to the vertically upward direction, and "upper" in terms such as upper part and upper surface refers to the vertically upward part. Similarly, "lower" refers to the vertically downward part, and the vertical direction is not precise and may include errors.

[0018] The solid fuel pulverizer 100 of this embodiment is an apparatus that pulverizes solid fuel, such as biomass fuel or coal, to generate pulverized fuel and supply it to a burner (combustion device) 220 of a boiler 200, for example. The power plant 1 including the solid fuel pulverizer 100 and the boiler 200 shown in FIG. 1 is equipped with one solid fuel pulverizer 100, but it may also be a system equipped with multiple solid fuel pulverizers 100 corresponding to each of the multiple burners 220 of one boiler 200.

[0019] The solid fuel pulverizing device 100 of this embodiment comprises a mill (pulverizing section) 10, a bunker (storage section) 21, a coal feeder (fuel supplying machine) 25, a blower (carrier gas supplying section) 30, a status detection section 40, and a control section 50.

[0020] The mill 10, which pulverizes solid fuel such as coal or biomass fuel to be supplied to the boiler 200 into finely divided fuel, which is a finely divided solid fuel, may be of a type that pulverizes only coal, or may be of a type that pulverizes only biomass fuel, or may be of a type that pulverizes biomass fuel together with coal. Here, biomass fuel refers to organic resources derived from renewable living organisms, such as thinned wood, waste wood, driftwood, grass, waste, sludge, tires, and recycled fuels (pellets and chips) made from these materials, but is not limited to the ones listed here.Biomass fuels are carbon neutral, meaning they do not emit carbon dioxide, a greenhouse gas, because they absorb carbon dioxide during the biomass growth process, and various uses for them are being considered.

[0021] The mill 10 comprises a housing 11, a grinding table 12, grinding rollers 13, a reducer (drive transmission unit) 14, a mill motor (drive unit) 15 connected to the reducer 14 and driving the grinding table 12 to rotate, a rotary classifier (classification unit) 16, a coal supply pipe (fuel supply unit) 17, and a classifier motor 18 that drives the rotary classifier 16 to rotate. The housing 11 is formed in a cylindrical shape extending in the vertical direction, and is a case that accommodates the crushing table 12, the crushing rollers 13, the rotary classifier 16, and the coal feed pipe 17. A coal feed pipe 17 is attached to the center of the ceiling portion 42 of the housing 11. This coal feed pipe 17 supplies solid fuel guided from the bunker 21 via the coal feeder 25 into the housing 11. It is disposed vertically at the center of the housing 11 and has its lower end extending into the interior of the housing 11.

[0022] A reducer 14 is installed near the bottom surface 41 of the housing 11, and a mill motor 15 connected to the reducer 14 transmits a driving force to rotate the grinding table 12, which is rotatably arranged. The grinding table 12 is a circular member in a plan view, and is arranged so that the lower end of the coal feed pipe 17 faces it. The upper surface of the grinding table 12 may, for example, have an inclined shape that is low in the center and rises toward the outside, with the outer periphery bending upward. The coal feed pipe 17 supplies solid fuel (in this embodiment, for example, coal or biomass fuel) from above toward the grinding table 12 below, and the grinding table 12 sandwiches the supplied solid fuel between itself and the grinding rollers 13 and grinds it.

[0023] When solid fuel is fed from the coal feed pipe 17 toward the center of the pulverizing table 12, the centrifugal force generated by the rotation of the pulverizing table 12 guides the solid fuel toward the outer periphery of the pulverizing table 12, where it is pinched and pulverized between the pulverizing table 12 and the pulverizing rollers 13. The pulverized solid fuel is blown upward by the carrier gas (hereinafter referred to as primary air) guided from the carrier gas flow path (hereinafter referred to as primary air flow path) 110, and is guided to the rotary classifier 16. An outlet (not shown) is provided on the outer periphery of the grinding table 12, through which primary air flowing in from the primary air flow path 110 flows out into the space above the grinding table 12 within the housing 11. A swirl blade (not shown) is provided at the outlet, which imparts a swirling force to the primary air blown out from the outlet. The primary air given a swirling force by the swirl blade becomes an airflow having a swirling velocity component, and transports the solid fuel pulverized on the grinding table 12 to the rotary classifier 16 located above in the housing 11. Of the pulverized solid fuel, particles larger than a predetermined particle size are classified by the rotary classifier 16, or fall without reaching the rotary classifier 16 and are returned to the grinding table 12, where they are pulverized again between the grinding table 12 and the grinding rollers 13.

[0024] The crushing roller 13 is a rotating body that crushes the solid fuel supplied onto the crushing table 12 from the coal supply pipe 17. The crushing roller 13 is pressed against the upper surface of the crushing table 12 and cooperates with the crushing table 12 to crush the solid fuel. 1 shows only one representative crushing roller 13, but multiple crushing rollers 13 are arranged at regular intervals in the circumferential direction so as to press against the upper surface of the crushing table 12. For example, three crushing rollers 13 are arranged at equal intervals in the circumferential direction on the outer periphery, at angular intervals of 120°. In this case, the portions of the three crushing rollers 13 that come into contact with the upper surface of the crushing table 12 (pressing portions) are equidistant from the rotational axis of the crushing table 12.

[0025] The crushing roller 13 can be swung and displaced up and down by the journal head 43, and is supported so as to be able to move towards and away from the upper surface of the crushing table 12. When the crushing table 12 rotates, the crushing roller 13 receives a rotational force from the crushing table 12 and rotates with it, with the outer circumferential surface of the crushing roller 13 in contact with the solid fuel on the upper surface of the crushing table 12. When solid fuel is supplied from the coal supply pipe 17, the solid fuel is pressed between the crushing roller 13 and the crushing table 12 and crushed. This pressing force is called the crushing load.

[0026] The support arm 44 of the journal head 43 is supported on the side of the housing 11 by a support shaft 45 whose middle portion is horizontally aligned, allowing the crushing roller 13 to swing and displace up and down about the support shaft 45. A pressing device (crushing load applying unit) 46 is provided at the upper end portion vertically above the support arm 44. The pressing device 46 is fixed to the housing 11 and applies a crushing load to the crushing roller 13 via the support arm 44, etc., so as to press the crushing roller 13 against the crushing table 12. The crushing load is applied, for example, by a hydraulic cylinder (not shown) operated by the pressure of hydraulic oil supplied from a hydraulic device (not shown) installed outside the mill 10. The crushing load may also be applied by the repulsive force of a spring (not shown).

[0027] The reducer 14 is connected to a mill motor 15, and transmits the driving force of the mill motor 15 to the grinding table 12, causing the grinding table 12 to rotate around its central axis.

[0028] The rotary classifier (classification unit) 16 is provided at the top of the housing 11 and has a hollow, inverted cone-like outer shape. The rotary classifier 16 is provided with a plurality of blades 16a extending in the vertical direction around its outer periphery. The blades 16a are provided at predetermined intervals (equally spaced) around the central axis of the rotary classifier 16. The rotary classifier 16 is a device that classifies solid fuel pulverized by the pulverizing table 12 and pulverizing rollers 13 (hereinafter, the pulverized solid fuel will be referred to as "pulverized fuel") into particles larger than a predetermined particle size (for example, 70 to 100 μm for coal) (hereinafter, pulverized fuel exceeding the predetermined particle size will be referred to as "coarse pulverized fuel") and particles smaller than the predetermined particle size (hereinafter, pulverized fuel smaller than the predetermined particle size will be referred to as "fine pulverized fuel"). The rotary classifier 16 is given a rotational driving force by a classifier motor 18 controlled by the control unit 50, and rotates around a coal feed pipe 17, centered on a cylindrical axis (not shown) extending in the vertical direction of the housing 11. The classifying section may be a fixed classifier having a fixed hollow inverted cone-shaped casing and a plurality of fixed swirl vanes on the outer periphery of the casing instead of the blades 16a.

[0029] When the pulverized fuel reaches the rotary classifier 16, due to the relative balance between the centrifugal force generated by the rotation of the blades 16a and the centripetal force of the primary air flow, large diameter coarse pulverized fuel particles are knocked down by the blades 16a and returned to the pulverizing table 12 to be pulverized again, and the fine pulverized fuel is led to the outlet port 19 in the ceiling 42 of the housing 11. The fine pulverized fuel classified by the rotary classifier 16 is discharged together with the primary air from the outlet port 19 into the pulverized fuel supply flow path (pulverized fuel supply pipe) 120 and supplied to the burner 220 of the boiler 200.

[0030] The coal feed pipe (fuel supply unit) 17 is attached so that its lower end extends vertically into the interior of the housing 11 so as to penetrate the ceiling portion 42 of the housing 11, and supplies solid fuel fed from the top of the coal feed pipe 17 to the center of the grinding table 12. A coal feeder 25 is connected to the upper end of the coal feed pipe 17, and solid fuel is supplied thereto.

[0031] The coal feeder 25 is connected to the bunker 21 by a downspout 22, which is a pipe extending vertically from the lower end of the bunker 21. A valve (coal gate, not shown) for switching the discharge state of the solid fuel from the bunker 21 may be provided midway through the downspout 22. The coal feeder 25 includes a conveying unit 26 and a coal feeder motor 27. The conveying unit 26 is, for example, a belt conveyor, and conveys the solid fuel discharged from the lower end of the downspout 22 to the upper part of the coal feed pipe 17 by the driving force of the coal feeder motor 27, and then deposits it inside. The amount of solid fuel supplied to the mill 10 is controlled by a signal from the control unit 50, for example, by adjusting the movement speed of the belt conveyor of the conveying unit 26.

[0032] Normally, primary air is supplied to the inside of the mill 10 to transport pulverized fuel to the burner 220, and the pressure is higher than that of the coal feeder 25 and the bunker 21. Inside the downspout section 22 that connects the bunker 21 and the coal feeder 25, fuel is layered. This solid fuel layer ensures a sealing property (material seal) that prevents the primary air and pulverized fuel from flowing back from the mill 10 toward the bunker 21.

[0033] The blower 30 is a device that blows primary air into the housing 11 to dry the pulverized fuel and transport it to the rotary classifier 16 . In this embodiment, the blower section 30 is equipped with a primary air fan (PAF) 31, a hot gas flow path 30a, a cold gas flow path 30b, a hot gas damper 30c, and a cold gas damper 30d in order to appropriately adjust the flow rate and temperature of the primary air blown into the inside of the housing 11.

[0034] In this embodiment, the hot gas flow path 30a supplies a portion of the air sent out from the primary air fan 31 as hot gas that has been heated by passing through an air preheater (heat exchanger) 34. A hot gas damper 30c is provided in the hot gas flow path 30a. The opening degree of the hot gas damper 30c is controlled by the control unit 50. The flow rate of the hot gas supplied from the hot gas flow path 30a is determined by the opening degree of the hot gas damper 30c.

[0035] The cold gas flow path 30b supplies a portion of the air sent out from the primary air ventilator 31 as cold gas at room temperature. A cold gas damper 30d is provided in the cold gas flow path 30b. The opening degree of the cold gas damper 30d is controlled by the control unit 50. The flow rate of the cold gas supplied from the cold gas flow path 30b is determined by the opening degree of the cold gas damper 30d.

[0036] In this embodiment, the flow rate of the primary air is the sum of the flow rate of the hot gas supplied from the hot gas flow path 30a and the flow rate of the cold gas supplied from the cold gas flow path 30b, and the temperature of the primary air is determined by the mixing ratio of the hot gas supplied from the hot gas flow path 30a and the cold gas supplied from the cold gas flow path 30b, and is controlled by the control unit 50. Furthermore, the oxygen concentration in the primary air blown from the primary air passage 110 into the housing 11 may be adjusted by, for example, introducing a portion of the combustion gas discharged from the boiler 200 by a gas recirculation fan (not shown) into the hot gas supplied from the hot gas passage 30a and mixing the same. By adjusting the oxygen concentration in the primary air, for example, when a highly ignitable (easily ignitable) solid fuel is used, it is possible to prevent the solid fuel from igniting on the path from the mill 10 to the burner 220.

[0037] In this embodiment, data measured or detected by the state detection unit 40 of the mill 10 is transmitted to the control unit 50. The state detection unit 40 of this embodiment is, for example, a differential pressure measurement means, and measures the differential pressure of the mill 10 as the differential pressure between the pressure at the portion where primary air flows from the primary air flow path 110 into the housing 11 and the pressure at the outlet port 19 where the primary air and pulverized fuel are discharged from the housing 11 into the pulverized fuel supply pipe 120. An increase or decrease in this differential pressure of the mill 10 corresponds to an increase or decrease in the amount of pulverized fuel circulating between the vicinity of the rotary classifier 16 inside the housing 11 and the vicinity of the grinding table 12 due to the classification effect of the rotary classifier 16. In other words, by adjusting the rotation speed of the rotary classifier 16 according to the differential pressure of the mill 10, the amount and particle size range of the pulverized fuel discharged from the outlet port 19 can be adjusted, so that the particle size of the pulverized fuel can be maintained within a range that does not affect the combustibility of the solid fuel in the burner 220, and an amount of pulverized fuel corresponding to the amount of solid fuel supplied to the mill 10 can be stably supplied to the burner 220 provided in the boiler 200. Furthermore, the state detection unit 40 of this embodiment is, for example, a temperature measurement means that detects the temperature of the primary air supplied to the inside of the housing 11 (mill inlet primary air temperature) and the temperature of the mixed gas of primary air and pulverized fuel at the outlet port 19 (mill outlet primary air temperature), and controls the blower unit 30 so that the respective upper limit temperatures do not exceed them. Each upper limit temperature is determined taking into consideration the possibility of ignition depending on the properties of the solid fuel. Note that, since the primary air is cooled inside the housing 11 by drying and transporting the pulverized fuel, the primary air temperature at the mill inlet is, for example, from room temperature to approximately 300°C, and the primary air temperature at the mill outlet is, for example, from room temperature to approximately 90°C.

[0038] The control unit 50 is a device that controls each part of the solid fuel pulverizer 100 . The control unit 50 may, for example, transmit a drive command to the mill motor 15 to control the rotation speed of the grinding table 12. The control unit 50, for example, transmits a drive command to the classifier motor 18 to control the rotational speed of the rotary classifier 16 to adjust the classification performance, and can stably supply to the burner 220 an amount of pulverized fuel corresponding to the amount of solid fuel supplied to the mill 10 while maintaining the particle size of the pulverized fuel within a range that does not affect the combustibility of the solid fuel in the burner 220. Furthermore, the control unit 50 can adjust the amount of solid fuel supplied to the mill 10 (amount of coal supply) by transmitting a drive command to the coal supply motor 27, for example. Furthermore, the control unit 50 can adjust the flow rate and temperature of the primary air by controlling the opening rates of the hot gas damper 30c and the cold gas damper 30d by transmitting an opening rate instruction to the blower unit 30. Specifically, the control unit 50 controls the opening rates of the hot gas damper 30c and the cold gas damper 30d so that the flow rate of the primary air supplied to the inside of the housing 11 and the temperature of the primary air at the outlet port 19 (mill outlet primary air temperature) become predetermined values ​​set corresponding to the coal feed rate for each type of solid fuel. Note that the temperature of the primary air may also be controlled by controlling the temperature at the mill inlet (mill inlet primary air temperature).

[0039] The control unit 50 is composed of, for example, a central processing unit (CPU), random access memory (RAM), read-only memory (ROM), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium, for example, in the form of a program. The CPU reads the program into the RAM and executes information processing and arithmetic operations to realize various functions. The program may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories. The HDD may be replaced with a solid-state disk (SSD), for example.

[0040] Next, a description will be given of the boiler 200 that generates steam by burning the pulverized fuel supplied from the solid fuel pulverizer 100. The boiler 200 includes a furnace 210 and a burner 220.

[0041] The burner 220 is a device that burns pulverized fuel to form a flame using a mixture of pulverized fuel and primary air supplied from the pulverized fuel supply pipe 120 and secondary air supplied by heating air (outside air) sent out from a forced draft fan (FDF) 32 with an air preheater 34. The pulverized fuel is burned in the furnace 210, and the high-temperature combustion gas passes through heat exchangers (not shown) such as an evaporator, a superheater, and a coal economizer before being discharged to the outside of the boiler 200.

[0042] The combustion gas discharged from the boiler 200 undergoes predetermined treatment in environmental equipment (such as a denitration device, dust collector, and desulfurization device, not shown), and then undergoes heat exchange with primary air and secondary air in an air preheater 34. The gas is then guided to a chimney (not shown) via an induced draft fan (IDF) 33 and released into the outside air. The air heated by the combustion gas in the air preheater 34 and delivered from the primary air fan 31 is supplied to the above-mentioned hot gas flow path 30a. The water supplied to each heat exchanger of the boiler 200 is heated in a coal economizer (not shown), and then further heated in an evaporator (not shown) and a superheater (not shown) to generate high-temperature, high-pressure superheated steam, which is then sent to the steam turbine (not shown), which is the power generation section, to rotate and drive the steam turbine, which then rotates and drives a generator (not shown) connected to the steam turbine to generate electricity, thereby constituting the power generation plant 1.

[0043] Next, the details of the crushing roller 13 according to this embodiment will be described in detail with reference to FIGS. As shown in FIGS. 1 and 2, each crushing roller 13 is supported relative to the housing 11 via a journal shaft 47, a journal head 43, and a support shaft 45 so as to be rotatable about the central rotation axis C2. The journal shaft 47 extends from near the side of the housing 11 toward the center of the housing 11, slanting downward. The journal shaft 47 has a base end (the end on the side of the housing 11) fixed to the journal head 43. The journal head 43 rotatably supports the crushing roller 13 at its tip end (the end on the center side of the mill 10) via a bearing (not shown). In other words, the crushing roller 13 is rotatably supported vertically above the crushing table 12, in an inclined state so that the upper side faces closer to the center of the housing 11 than the lower side.

[0044] 2, the crushing roller 13 includes a journal housing (support portion) 48 that is supported at the tip of a journal shaft 47 so as to be rotatable about a central rotation axis C2, and an annular roller portion 49 that is fitted onto the journal housing 48. The journal housing 48 is provided so as to cover the tip of the journal shaft 47, and has a cylindrical outer circumferential surface.

[0045] FIG. 3 shows a main part of a cross section of the roller portion 49 taken along a plane including the direction in which the rotational center axis C2 of the roller portion 49 extends (hereinafter referred to as an "axial cross section"). The roller portion 49 has a first portion 49A disposed on the base end side in the direction in which the rotation center axis C2 extends (hereinafter referred to as the "axial direction"), and a second portion 49B disposed alongside the first portion 49A along the axial direction. In other words, the roller portion 49 is divided into two in the axial direction, the first portion 49A and the second portion 49B. Here, the base end side refers to the journal shaft 47 side to which the crushing roller 13 is connected, and indicates the outer circumferential side in the radial direction of the crushing table 12 (the right side of the paper in FIG. 3), and the tip side refers to the rotation center axis C1 (see FIG. 1) side in the radial direction of the crushing table 12 (the left side of the paper in FIG. 3).

[0046] The first portion 49A and the second portion 49B are fixed with fixing bolts 53. During operation of the mill 10, the first portion 49A and the second portion 49B are disposed at positions at different distances from the rotation center axis C1 of the grinding table 12, and therefore tend to rotate at different peripheral speeds. Therefore, a shear force is generated at the joint surface between the first portion 49A and the second portion 49B, causing the first portion 49A and the second portion 49B to move relative to each other in a sliding manner. If such relative movement occurs, the joint surface will be worn due to the sliding, so it is preferable that the first portion 49A and the second portion 49B be fixed so that the relative movement between them is restricted.

[0047] The roller portion 49 is formed uniformly in the circumferential direction, that is, the axial cross section has substantially the same structure at any position in the circumferential direction. As shown in FIG. 3, the outer peripheral surface 49a of the roller portion 49 is curved in an axial cross section so as to form an arc centered on the center point CP.

[0048] 3, the first portion 49A and the second portion 49B are symmetrical with respect to the center line C3. Therefore, the following will describe the configuration of the first portion 49A in detail, and will omit any unnecessary explanation of the configuration of the second portion 49B. The center line C3 is a line that is perpendicular to the rotational axis C2 and passes through the center of the crushing roller 13 in the direction in which the rotational axis C2 extends. In this embodiment, the surface where the first portion 49A and the second portion 49B come into contact overlaps with the center line C3.

[0049] 3, first portion 49A integrally includes first base portion 51A made of high chromium cast iron that fits into journal housing 48, and first ceramic portion (outer periphery) 52A that includes a ceramic member provided on the outer periphery of first base portion 51A. In other words, roller portion 49 according to this embodiment is a so-called ceramic-embedded high chromium cast iron roller.

[0050] The first base portion 51A is supported by the journal housing 48. The first base portion 51A is formed in a substantially annular shape. The first base portion 51A is fitted to the journal housing 48 so that the inner peripheral surface of the first base portion 51A contacts the outer peripheral surface of the journal housing 48. The first ceramic portion 52A is fixed to the outer peripheral portion of the annular first base portion 51A. The first ceramic portion 52A is provided over substantially the entire circumferential area of ​​the first base portion 51A. In other words, the first ceramic portion 52A is formed in a substantially annular shape. The first base portion 51A has a bolt hole formed therethrough in the axial direction. The outer peripheral surface of the first base portion 51A is inclined in the axial cross section from the center line C3 toward the base end in the axial direction so as to approach the central axis of rotation C2. The inner peripheral surface of the first base portion 51A is a cylindrical surface. The surface of the first base portion 51A on the second portion 49B side (that is, the surface that abuts against the second base portion 51B) is flat.

[0051] Because the first ceramic portion 52A includes a ceramic member, it has a smaller linear expansion coefficient than the first base portion 51A, which is made of high-chromium cast iron. The first ceramic portion 52A also has better wear resistance than the first base portion 51A. The materials of the first base portion 51A and the first ceramic portion 52A are not limited to those described above. The first ceramic part 52A is formed in a substantially annular shape. The first ceramic part 52A covers the entire outer peripheral surface of the first base part 51A from the outside. The inner peripheral surface of the first ceramic part 52A abuts against the outer peripheral surface of the first base part 51A. The outer peripheral surface of the first ceramic part 52A is curved in an axial cross section so as to form an arc centered on a center point CP. The surface of the first ceramic portion 52A facing the second portion 49B (that is, the surface in contact with the second ceramic portion 52B) is flat.

[0052] In this way, the outer peripheral surface of the roller portion 49 is formed by the first ceramic portion 52A and the second ceramic portion 52B over the entire area in the axial direction.

[0053] Next, the joining mode between the first portion 49A and the second portion 49B will be described. The first portion 49A is fixed to the second portion 49B by a fixing bolt 53 inserted through a linear hole that connects a bolt hole 54 formed in the first base portion 51A of the first part 49A and a bolt hole 54 formed in the second base portion 51B of the second part 49B. A head 53a of the fixing bolt 53 abuts the first base portion 51A. A nut 55 threaded onto the tip of the fixing bolt 53 abuts the second base portion 51B. Therefore, by fastening the fixing bolt 53 and the nut 55, the first base portion 51A and the second base portion 51B are fixed together. This joins the first portion 49A and the second part 49B. The fixing bolt 53 and the nut 55 may be a so-called headless cut bolt with nuts on both ends.

[0054] The dashed line L1 in FIGS. 2 and 3 indicates the progression of wear on the roller portion 49 as the mill 10 grinds the solid fuel. In other words, in this embodiment, the roller portion 49 is in a state where a portion P1 (hereinafter referred to as the "maximum wear point P1") on the base end side (i.e., the side opposite the tip end side) of the roller portion 49 is worn more than other portions. As described above, the base end side refers to the outer circumferential side in the radial direction of the grinding table 12, and the tip end side refers to the side of the rotation center axis C1 (see FIG. 1) of the grinding table 12. The dashed line L2 in FIG. 2 indicates the progression of wear on the grinding table 12. That is, the maximum wear point P1 is located on the first ceramic portion 52A. In FIGS. 2 and 3, the maximum wear point before wear is indicated by the symbol "P1," and the maximum wear point after wear has actually progressed is indicated by the symbol "P1'." In other words, the maximum wear point P1 before wear is the point where wear is expected to progress most easily.

[0055] The maximum wear point P1 is located on the outer peripheral surface 49a of the roller portion 49 at a predetermined angle θ1 toward the base end with respect to the center line C3 (a line perpendicular to the rotation axis C2 and passing through the center of the crushing roller 13 in the direction of the rotation axis C2). More specifically, it is located at the point where the outer peripheral surface 49a intersects with a line L4 that forms a predetermined angle θ1 with the center line C3 at the center point CP. While the angle θ1 in FIG. 3 is 8 degrees as an example, the angle θ1 is not limited to 8 degrees. The location of the maximum wear point P1 varies depending on, for example, the specifications of the mill 10 and the solid fuel being crushed, and the angle θ1 often occurs within a range of 3 to 13 degrees (a range of 8 degrees plus or minus 5 degrees). In this embodiment, the thickness of the first ceramic portion 52A in the axial cross section is greatest at a portion where a line L4 that forms a predetermined angle θ1 with the center line C3 passes.

[0056] Furthermore, dashed line L3 in FIG. 3 indicates the progression of wear of the roller portion 49 as the mill 10 grinds the solid fuel when the roller portion 49 is inverted and used after it has worn as indicated by dashed line L1 (i.e., when the roller portion 49 is removed from the journal housing 48, the base end and the tip end are swapped, and the roller portion 49 is reattached to the journal housing 48 for use). In this case, the maximum wear point P2 is located symmetrically with respect to the center line C3. Specifically, the maximum wear point P2 is located on line L5, which is symmetrical with line L4, which forms a predetermined angle θ1 with the center line C3. In other words, the maximum wear point P2 when inverted is located on the second ceramic portion 52B. Note that in FIG. 2, the maximum wear point before wear is indicated by the symbol "P2," and the maximum wear point after actual wear is indicated by the symbol "P2'." In other words, the maximum wear point P2 before wear is the point where wear is expected to progress most easily. 3 illustrates a state in which the roller part 49 is not inverted, and therefore, when the roller part 49 is actually inverted, the second ceramic part 52B will be located closer to the base end than the center line C3 (to the right in FIG. 3). Therefore, the maximum wear point P2 will also be located closer to the base end than the center line C3 (to the right in FIG. 3), similar to the maximum wear point P1 before inversion.

[0057] Next, a method for manufacturing the roller portion 49 will be described with reference to Fig. 4. UP in Fig. 4 indicates the upward direction in the vertical direction. First, when manufacturing the roller portion 49, the first portion 49A is manufactured first. When manufacturing the first portion 49A, ceramic particles are first shaped into a block (a shape corresponding to the first ceramic portion 52A) to manufacture a ceramic block CB (see FIG. 4) that constitutes part of the first ceramic portion 52A. The ceramic block is made by bonding ceramic particles, and a relatively large number of gaps are formed between the ceramic particles. The outer shape of the ceramic block CB is approximately the same as the outer shape of the first ceramic portion 52A.

[0058] Next, the manufactured ceramic block CB is placed at a predetermined position in the mold 60. At this time, the ceramic block CB is fixed at the predetermined position by being sandwiched between the ceiling and bottom surfaces of the mold 60. In this embodiment, the ceramic block CB is sandwiched between the ceiling and bottom surfaces of the mold 60, and is fixed at the predetermined position by buoyancy during casting, as will be described later. Next, molten metal is poured into the mold 60 from the gate 61 through the runner 62. This fills the mold 60 with the molten metal (see arrow m). At this time, the ceramic block CB has a lower specific gravity than the molten metal, so it is pressed against a predetermined position on the inner circumferential surface of the mold 60 by buoyancy (see arrow b), as shown in FIG. 4. At this time, the molten metal also flows into the gaps formed between the ceramic particles of the ceramic block CB.

[0059] The molten metal is then cooled and solidified, completing roller 49, which is an integrated unit of first ceramic portion 52A, which has excellent abrasion resistance and in which metal is embedded between the ceramic particles of ceramic block CB, and first base portion 51A, which is made entirely of solidified metal.

[0060] In this manner, the first portion 49A of the present embodiment is manufactured by insert-casting the first base portion 51A and the first ceramic portion 52A. Note that the bolt holes 54 may be formed by casting when the first portion 49A is cast. Because the first base portion 51A is very hard, it is difficult to form the bolt holes 54 after solidification. Therefore, by forming the bolt holes by casting in this manner, the bolt holes 54 can be easily formed.

[0061] Next, the second portion 49B is manufactured. The method for manufacturing the second portion 49B is the same as the method for manufacturing the first portion 49A, and therefore a description thereof will be omitted.

[0062] Next, the first portion 49A and the second portion 49B are joined by tightening the fixing bolts 53 and nuts 55. In this manner, the roller portion 49 is manufactured. Note that the joining of the first portion 49A and the second portion 49B is performed in a factory, and the joined roller portion 49 is transported to the site where the mill 10 is assembled, thereby reducing the number of assembly steps on site and reducing the total cost.

[0063] According to this embodiment, the following advantageous effects are achieved. In this embodiment, the first portion 49A is provided on one side (base end side) of the axial center line C3, and the second portion 49B is provided on the other side (tip end side) of the axial center line C3. This allows the ceramic portions 52 (first ceramic portion 52A and second ceramic portion 52B) with excellent wear resistance to be provided on both sides of the roller portion 49. Therefore, even when the roller portion 49 is used in an inverted state (i.e., when the roller portion 49 is removed, inverted so that one side is reversed, and then reattached), the solid fuel can be crushed between the ceramic portions 52 and the grinding table 12, thereby suppressing wear of the roller portion 49. This extends the life of the roller portion 49.

[0064] In this embodiment, the roller portion 49 has a first portion 49A and a second portion 49B. This allows the first portion 49A and the second portion 49B to be manufactured separately. Therefore, by fixing the separately manufactured first portion 49A and second portion 49B together, the ceramic portions 52 (the first ceramic portion 52A and the second ceramic portion 52B) can be easily provided on both sides in the axial direction.

[0065] Furthermore, because the first portion 49A and the second portion 49B can be manufactured separately, the volume of the parts manufactured at one time can be reduced compared to manufacturing the first portion 49A and the second portion 49B at the same time. This allows the volume of the parts manufactured in one casting operation to be reduced when manufacturing the first portion 49A and the second portion 49B by casting, thereby reducing the amount of molten metal required for one casting operation. This allows the blast furnace used to manufacture the molten metal to be downsized. This allows for space-saving equipment for manufacturing the crusher rollers 13, and reduces the initial cost of the equipment.

[0066] Furthermore, because the first portion 49A and the second portion 49B can be manufactured separately, even if a defect occurs during the manufacturing of each portion, it is not necessary to discard the entire roller portion 49, and the amount of waste can be reduced. This improves the yield when manufacturing the crushing roller 13. Furthermore, when manufacturing the roller portion 49 again, if the discarded portion is remelted and reused, the cost of melting can be reduced.

[0067] Furthermore, since the first ceramic portion 52A and the second ceramic portion 52B can be manufactured separately, the amount of waste can also be reduced when manufacturing the ceramic block CB.

[0068] [Variation 1] Next, a modified example of this embodiment will be described with reference to Fig. 5. In Fig. 5, UP indicates the upward direction in the vertical direction. In this embodiment, the method for manufacturing the second portion 49B and the method for joining the first portion 49A and the second portion 49B are different from those in the above embodiment. Since the other configurations are the same as those in the above embodiment, the same reference numerals are used for the same configurations, and detailed descriptions thereof will be omitted.

[0069] In this modification, the first portion 49A and the second portion 49B are joined and integrated by casting. Specifically, the completed first portion 49A is placed in the lower portion of the mold 160. At this time, the first portion 49A is sufficiently preheated. If molten metal were poured into the first portion 49A after it was placed in the mold 160, the first portion 49A would act like a chill during casting, causing the molten metal to cool and contract, potentially resulting in the formation of shrinkage cavities inside the second portion 49B. Preheating the first portion 49A reduces the degree of cooling of the molten metal, thereby suppressing the formation of shrinkage cavities. The method for manufacturing the first portion 49A is the same as in the above embodiment.

[0070] Next, the manufactured ceramic block CB for the second portion 49B is placed at a predetermined position in the mold 160. At this time, the ceramic block CB is sandwiched between the ceiling surface of the mold 160 and the first portion 49A (first ceramic portion 52A), thereby fixing the ceramic block CB in the predetermined position.

[0071] Next, molten metal is poured into the mold 160 from the gate 61 through the runner 62. At this time, the molten metal is poured into the space above the first portion 49A. As a result, the mold 160 is filled with the molten metal (see arrow m).

[0072] Next, the molten metal is cooled and solidified, thereby producing the second portion 49B. At this time, the second portion 49B is produced in a state where it is joined and integrated with the first portion 49A. In this modified example, the roller portion 49 is manufactured in this manner.

[0073] According to this modification, the second portion 49B has a shape corresponding to the joining surface of the first portion 49A, so there is no need to perform machining or the like on the joining surfaces of the first portion 49A and the second portion 49B, and therefore the machining step can be omitted.

[0074] 5, the first portion 49A may have a protruding portion 70 having a generally T-shaped cross section. The protruding portion 70 protrudes from the surface of the first base portion 51A on the second portion 49B side. The protruding portion 70 is formed so as to be integrated with the first base portion 51A when the first portion 49A is cast. With this configuration, when the second portion 49B is manufactured, the protrusion 70 is embedded in the second portion 49B, so that the first portion 49A and the second portion 49B can be joined more firmly.

[0075] In this manner, in this modification, the first portion 49A and the second portion 49B are joined by casting. Therefore, the fixing bolts 53 and nuts 55 described in the above embodiment are not provided on the roller portion 49. Furthermore, the first base portion 51A and the second base portion 51B do not have bolt holes 54 formed therein.

[0076] [Variation 2] Next, a modification of this embodiment will be described with reference to FIG. In this modified example, the method for joining the first portion 49A and the second portion 49B is different from that of the above embodiment. Since the other configurations are the same as those of the above embodiment, the same reference numerals are used for the similar configurations, and detailed descriptions thereof will be omitted.

[0077] In this modification, the first portion 49A and the second portion 49B are joined together using a fixing portion 80. The fixing portion 80 integrally includes a cylindrical portion 81 provided between the journal housing 48 and the first and second base portions 51A, 51B, a first abutment portion 82 extending radially outward from one axial end of the cylindrical portion 81 and abutting against one axial end face of the first base portion 51A, and a second abutment portion 83 extending radially outward from the other axial end of the cylindrical portion 81 and abutting against the other axial end face of the second base portion 51B.

[0078] The fixing portion 80 is made of a material (for example, carbon steel) that is lower in hardness than the first base portion 51A and the second base portion 51B and that is easily machined. The cylindrical portion 81 is formed with a bolt hole 81a through which the fixing bolt 53 is inserted.

[0079] In this modification, the first base portion 51A is fitted from the outside to the outer periphery of the journal housing 48 via the cylindrical portion 81. The second base portion 51B is fitted from the outside to the outer periphery of the journal housing 48 via the cylindrical portion 81.

[0080] In this modified example, the first abutment portion 82 and the second abutment portion 83 are fixed by a fixing bolt 53 that is inserted through the cylindrical portion 81. A head 53a of the fixing bolt 53 abuts against the first abutment portion 82. Furthermore, a nut 55 that threads onto the tip of the fixing bolt 53 abuts against the second abutment portion 83. Therefore, by fastening the fixing bolt 53 and the nut 55, the first abutment portion 82 and the second abutment portion 83 sandwich the first base portion 51A and the second base portion 51B from both sides in the axial direction. Therefore, the first portion 49A and the second portion 49B can be joined. Furthermore, since the fixing portion 80 has a lower hardness than the first base portion 51A, etc., it can be easily machined. This makes it easier to insert the fixing bolt 53 than when the bolt hole 81a is formed in the first base portion 51A, etc. Therefore, the crusher roller 13 can be manufactured easily.

[0081] In this manner, in this modification, the first portion 49A and the second portion 49B are joined together using the fixing portion 80. Therefore, the fixing bolts 53 and nuts 55 described in the above embodiment are not provided on the roller portion 49. Furthermore, the first base portion 51A and the second base portion 51B do not have bolt holes 54 formed therein.

[0082] [Variation 3] Next, a modification of this embodiment will be described with reference to FIG. This modification differs from the above embodiment in that the first portion 49A and the second portion 49B have recesses. Since the other configurations are the same as those in the above embodiment, the same reference numerals are used for the same configurations, and detailed descriptions thereof will be omitted.

[0083] In this modification, the first base portion 51A has a first recess 51Ab recessed from a first contact surface 51Aa that contacts the second base portion 51B. The second base portion 51B has a second recess 51Bb recessed from a second contact surface 51Ba that contacts the first base portion 51A.

[0084] The first recess 51Ab and the second recess 51Bb form a closed space S.

[0085] In this modification, the first base 51A and the second base 51B have recesses. This allows the volumes of the first base 51A and the second base 51B to be reduced compared to configurations without recesses. This allows, for example, to reduce the amount of molten metal required for one casting when manufacturing the first portion 49A and the second portion 49B by casting. This allows the size of the blast furnace that produces the molten metal to be reduced. This allows for space-saving equipment for manufacturing the crusher roller 13 and reduced initial costs for the equipment.

[0086] Furthermore, a detector 90 for detecting wear of the first ceramic part 52A and the second ceramic part 52B may be provided in the closed space S formed by the first recess 51Ab and the second recess 51Bb. This allows for detection of wear of the first ceramic part 52A and the second ceramic part 52B. Furthermore, by providing the detector 90 in the recesses formed in the first base part 51A and the second base part 51B, the distance between the detector 90 and the object to be detected by the detector 90 (in this modification, the first ceramic part 52A and the second ceramic part 52B) can be made relatively short. This allows for a simplified structure of the wear detection means. Furthermore, since the detection unit 90 is provided inside the closed space S, the pulverized solid fuel and the like are unlikely to come into contact with the detection unit 90. Therefore, the detection unit 90 can be made less susceptible to damage. The wear detection method used by the detector 90 may be an electrical method using a probe or a method using sound waves.

[0087] [Variation 4] Next, a modification of this embodiment will be described with reference to Fig. 8. This modification differs from the above embodiment in that a hanging piece 91 is sandwiched between the joint surfaces of the first portion 49A and the second portion 49B. Since the other configurations are the same as those of the above embodiment, the same reference numerals are used for the same configurations, and detailed descriptions thereof will be omitted.

[0088] In this modification, as described above, the hanging piece 91 is sandwiched between the joint surfaces of the first portion 49 A and the second portion 49 B. The hanging piece 91 is engaged with an eyebolt 92. The grinding roller 13 is provided with hanging bolt holes that are used when installing or maintaining the mill 10. Hanging bolt holes are sometimes formed by casting easily machined carbon hanging pieces into the roller part 49. During this casting, there is a risk that part of the hanging piece will melt and the molten metal from the hanging piece will get mixed into the metal structure of the base of the roller part 49. On the other hand, in this modification, the hanging piece 91 is sandwiched between the joint surfaces of the first portion 49A and the second portion 49B, so that it is possible to suppress the mixing of different metals during casting.

[0089] [Variation 5] Next, a modification of this embodiment will be described with reference to Figure 9. This modification differs from the above embodiment in that the roller portion 49 is engaged with the journal housing 48. Other configurations are the same as those of the above embodiment, so the same components are denoted by the same reference numerals and detailed description thereof will be omitted. In this modification, the first base portion 51A and the second base portion 51B have engagement recesses 95 recessed from the surfaces that abut against the journal housing 48. The journal housing 48 has engagement protrusions 96 on the surfaces that abut against the first base portion 51A and the second base portion 51B that are accommodated in the engagement recesses 95 and thereby engage with the engagement recesses 95.

[0090] In this modification, the journal housing 48 has an engaging protrusion 96 that engages with the engaging recess 95. As a result, the engaging recess 95 engages with the engaging protrusion 96, restricting relative movement between the journal housing 48 and the first and second base portions 51A, 51B. This allows the journal housing 48 to be firmly fixed to the first and second base portions 51A, 51B.

[0091] Furthermore, the engaging protrusions 96 are housed within the engaging recesses 95. This makes it less likely that the pulverized solid fuel will come into contact with the engaging protrusions 96, compared to when an engaging portion between the roller portion 49 and the journal housing 48 is provided at the axial end of the crushing roller 13. This makes it possible to reduce the wear of the engaging protrusions 96. The engaging protrusions 96 may be detachable from the journal housing 48, allowing the crushing roller 13 to be attached to only one side of the journal housing 48. Specifically, the first portion 49A may first be installed in the journal housing 48, followed by the engaging protrusions 96, and then the second portion 49B, which are then installed and joined.

[0092] Furthermore, compared to providing an engagement portion between the roller portion 49 and the journal housing 48 at the axial end of the crushing roller 13, the axial length of the crushing roller 13 can be shortened while maintaining the width of the crushing surface, so even on a crushing table 12 of the same diameter, the crushing surface of the crushing roller 13 can be installed further outward from the crushing table 12. Therefore, it is possible to achieve a crushing unit of a size closer to that of a larger mill while suppressing an increase in the outer diameter of the housing 11 that houses these crushing units, making it possible to achieve a compact, large-capacity mill.

[0093] The present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure. For example, the solid fuel used is not limited to that disclosed herein, and may be coal, biomass fuel, petroleum coke (PC), etc. Furthermore, these solid fuels may be used in combination. Furthermore, for example, if only the first portion 49A or the second portion 49B is worn or damaged, it is possible to replace only either the first portion 49A or the second portion 49B. This allows the material cost of the maintenance cost for the crushing roller 13 to be reduced by half. Furthermore, a structure for preventing the intrusion of pulverized fuel may be provided on the joint surfaces of the first portion 49A and the second portion 49B, for example, by applying or filling a liquid gasket or a paste-like sealant.

[0094] The crushing roller, the solid fuel crushing device, and the method of manufacturing the crushing roller according to the above-described embodiments can be understood, for example, as follows. A crushing roller according to one aspect of the present disclosure is a crushing roller (13) that is housed inside a housing (11), that crushes solid fuel by sandwiching it between itself and a rotating crushing table (12), and that rotates with the rotational force from the crushing table (12). The crushing roller (13) includes a support portion (48) that is supported by the housing (11) so as to be rotatable about a central axis (C2), and an annular roller portion (49) that fits onto the outer periphery of the support portion (48) from the outside and crushes solid fuel between itself and the crushing table (12). The roller portion (49) has a first portion (49A) and is arranged alongside the first portion (49A) along an axial direction that is the direction in which the rotational central axis (C2) of the roller portion (49) extends. and a second part (49B) placed on the support part (48) and fixed to the first part (49A), the first part (49A) having a first base part (51A) fitted from the outside to the outer periphery of the support part (48) and a first outer periphery part (52A) provided on the outer periphery surface of the first base part (51A) and having higher wear resistance than the first base part (51A), and is provided on one side of the center line (C3) in the axial direction, and the second part (49B) having a second base part (51B) fitted from the outside to the outer periphery of the support part (48) and a second outer periphery part (52A) provided on the outer periphery surface of the second base part (51B) and having higher wear resistance than the second base part (51B), and is provided on the other side of the center line (C3) in the axial direction.

[0095] In the above configuration, the first portion is provided on one side of the axial centerline, and the second portion is provided on the other side of the axial centerline. This allows outer circumferential portions (first outer circumferential portion and second outer circumferential portion) with excellent wear resistance to be provided on both sides of the roller portion. Therefore, even when the roller portion is used in an inverted state (i.e., when the roller portion is removed, inverted so that one side is swapped with the other side, and then reattached and used), the solid fuel can be pulverized by the outer circumferential portion, thereby suppressing wear on the roller portion. This allows the life of the roller portion to be extended. In addition, in the above configuration, the roller portion has a first portion and a second portion. This allows the first portion and the second portion to be manufactured separately. Therefore, by fixing the separately manufactured first portion and the second portion together, it is possible to easily provide outer circumferential portions on both sides in the axial direction. Furthermore, since the first and second parts can be manufactured separately, the volume of the parts manufactured at one time can be reduced compared to manufacturing the first and second parts at the same time. Therefore, for example, when manufacturing the first and second parts by casting, the volume of the parts manufactured in one casting can be reduced, and the amount of molten metal required for one casting can be reduced. Therefore, the blast furnace for manufacturing the molten metal can be made smaller. Therefore, the equipment for manufacturing the crusher rollers can be made more space-saving, and the initial cost of the equipment can be reduced. Furthermore, because the first and second parts can be manufactured separately, even if a defect occurs during the manufacturing of each part, there is no need to discard the entire roller unit, and the amount of waste can be reduced. This improves the yield when manufacturing the crushing roller. Furthermore, when the discarded parts are melted to remanufacture the roller unit, the cost of melting can be reduced.

[0096] In addition, in a crushing roller according to one aspect of the present disclosure, the roller portion (49) includes a cylindrical portion (81) provided between the support portion (48) and the first base portion (51A) and the second base portion (51B), a first abutment portion (82) extending radially outward from one end of the cylindrical portion (81) in the axial direction (C2) and abutting against an end face of the first base portion (51A) in the axial direction (C2), and a second abutment portion (82) extending radially outward from the other end of the cylindrical portion (81) in the axial direction (C2) and abutting against an end face of the second base portion (51B) in the axial direction (C2). The first base portion (51A) is fitted from the outside to the outer periphery of the support portion (48) via the cylindrical portion (81), and the second base portion (51B) is fitted from the outside to the outer periphery of the support portion (48) via the cylindrical portion (81). The first abutment portion (82) and the second abutment portion (83) are fixed by a bolt (53) that passes through the fixing portion (80), and the cylindrical portion (81) is formed of a material that is lower in hardness than the first base portion (51A) and the second base portion (51B).

[0097] In the above configuration, the first and second contact portions are fixed by a bolt that passes through the fixing portion. This causes the first and second contact portions to sandwich the first and second base portions from both sides in the axial direction. Therefore, the first and second portions can be fixed. Furthermore, since the cylindrical portion has a lower hardness than the base portion, it can be easily machined. This makes it easier to insert bolts than when bolt holes are formed in the base portion. This makes it easier to manufacture the crushing roller.

[0098] In addition, in one embodiment of the crushing roller of the present disclosure, the first portion (49A) and the second portion (49B) are fixed by a fastener (53) inserted through a linear bolt hole (54) that connects a hole formed in the first base (51A) with a hole formed in the second base (52B).

[0099] In the above configuration, the first part and the second part are fixed together only by the fastener. This allows the first part and the second part to be fixed together without using any bulky parts (for example, parts that secure the first part and the second part by sandwiching them from the outside). This simplifies the structure.

[0100] In addition, in a crushing roller according to one embodiment of the present disclosure, the first base (51A) has a first contact surface (51Aa) that contacts the second base (51B) and a first recess (51Ab) recessed from the first contact surface (51Aa), and the second base (51B) has a second contact surface (51Ba) that contacts the first contact surface (51Aa) of the first base (51A) and a second recess (51Bb) recessed from the second contact surface (51Ba).

[0101] In the above configuration, the first base and the second base have recesses. This allows the volumes of the first base and the second base to be reduced compared to a configuration without recesses. As a result, for example, when the first part and the second part are manufactured by casting, the volume of the parts manufactured in one casting can be reduced, thereby reducing the amount of molten metal required for one casting. This allows the blast furnace that produces the molten metal to be made smaller. This allows the equipment for manufacturing the crusher rollers to be space-saving and the initial cost of the equipment to be reduced.

[0102] In addition, in a crushing roller according to one embodiment of the present disclosure, the first recess (51Ab) and the second recess (51Bb) form a closed space, and a detection unit (90) is provided in the closed space to detect wear of the first outer peripheral portion (52A) and / or the second outer peripheral portion.

[0103] In the above configuration, the closed space formed by the first recess and the second recess can reduce the volume of the first base and the second base. This reduces the amount of molten metal required for one casting when manufacturing the first and second parts. This allows the blast furnace used to manufacture the molten metal to be downsized. This allows for space-saving equipment for manufacturing the crushing rollers and reduces the initial cost of the equipment. Furthermore, a detector for detecting wear on the first outer periphery and / or the second outer periphery is provided in the closed space formed by the first recess and the second recess. This makes it possible to detect wear on the first outer periphery and / or the second outer periphery. Furthermore, by providing the detector in a recess formed in the base, the distance between the detector and the object (the first outer periphery and / or the second outer periphery) detected by the detector can be made relatively short. This allows for a simplified structure of the wear detection means. Furthermore, since the detection unit is provided in a closed space, the pulverized solid fuel and the like are unlikely to come into contact with the detection unit, which makes it difficult for the detection unit to be damaged.

[0104] In addition, in a crushing roller according to one embodiment of the present disclosure, the first base (51A) and / or the second base (51B) has an engagement recess (95) recessed from a surface that abuts against the support portion (48), and the support portion (48) has an engagement protrusion (96) on a surface that abuts against the first base (51A) and / or the second base (51B) that is accommodated in the engagement recess (95) and thereby engages with the engagement recess (95).

[0105] In the above configuration, the support portion has an engaging protrusion that engages with the engaging recess. As a result, the engaging recess engages with the engaging protrusion, restricting relative movement between the support portion and the first base portion and / or the second base portion. This allows the support portion to be firmly fixed to the first base portion and / or the second base portion. Furthermore, the engaging protrusions are housed within the engaging recesses, which makes it less likely for the pulverized solid fuel to come into contact with the engaging protrusions, compared to when an engaging portion between the roller and the journal housing is provided at the axial end of the crushing roller, thereby making it less likely for the engaging protrusions to be damaged.

[0106] In addition, a solid fuel pulverizing device according to one embodiment of the present disclosure includes a pulverizing roller (13) as described above, a pulverizing table (12) that rotates and pulverizes the solid fuel by sandwiching it between the pulverizing roller (13) and the pulverizing table (12), and a housing (11) that accommodates the pulverizing roller (13) and the pulverizing table (12).

[0107] Further, a manufacturing method of a crushing roller according to one aspect of the present disclosure is a manufacturing method of a crushing roller (13) that is housed inside a housing (11), crushes solid fuel by sandwiching it between itself and a rotating crushing table (12), and rotates with rotational force from the crushing table (12), the crushing roller (13) comprising: a support part (48) that is supported rotatably about a central axis (C2) with respect to the housing (11); and an annular roller part (49) that fits onto the outer periphery of the support part (48) from the outside and crushes solid fuel between itself and the crushing table (12), the roller part (49) comprising a first part (49A) and a second part ( the first portion (49A) has a first base portion (51A) fitted from the outside to the outer periphery of the support portion (48), and a first outer periphery portion (52A) provided on the outer periphery surface of the first base portion (51A) and having higher wear resistance than the first base portion (51A), and is provided on one side of a center line (C3) in the axial direction; the second portion (49B) has a second base portion (51B) fitted from the outside to the outer periphery of the support portion (48), and a second outer periphery portion (52A) provided on the outer periphery surface of the second base portion (51B) and having higher wear resistance than the second base portion (51B), and is provided on the other side of the center line (C3) in the axial direction, and the method includes a step of manufacturing the first portion (49A), a step of manufacturing the second portion (49B), and a step of fixing the first portion (49A) and the second portion (49B).

[0108] In addition, in a method for manufacturing a crushing roller according to one embodiment of the present disclosure, the step of manufacturing the second portion (49B) and the step of fixing the first portion (49A) and the second portion (49B) together are carried out by placing the first portion manufactured in the step of manufacturing the first portion in a mold (160) having a shape corresponding to the crushing roller, pouring molten metal into the mold (160), and then cooling the molten metal to manufacture the second portion (49B) and fix the first portion (49A) and the second portion (49B) together.

[0109] In the above configuration, the second part has a shape corresponding to the joining surface of the first part, so there is no need to perform machining or the like on the joining surfaces of the first part and the second part, and therefore the machining step can be omitted.

[0110] In the method for manufacturing a crusher roller according to one aspect of the present disclosure, the first portion (49A) has a protrusion (70) that protrudes from the surface on the second portion (51B) side.

[0111] In the above configuration, the protrusion is embedded in the second part when the second part is manufactured, so that the first part and the second part can be joined more firmly. [Explanation of symbols]

[0112] 1: Power plant 10: Mill 11: Housing 12: Grinding table 13: Crushing roller 14:Reducer 15: Mill motor 16: Rotary classifier 16a: Blade 17: Coal feed pipe 18: Classifier motor 19: Exit port 21: Banka 22: Downspout section 25:Coal feeding machine 26: Transport unit 27: Coal feeder motor 30: Blower 30a: Hot gas flow path 30b: Cold gas flow path 30c: Thermal gas damper 30d: Cold gas damper 31: Primary air ventilator 34: Air preheater 40: Status detection unit 41: Bottom part 42: Ceiling 43: Journal head 44: Support arm 45: Support shaft 46: Pressing device 47: Journal shaft 48: Journal housing (support part) 49: Roller part 49A: 1st part 49B: 2nd part 49a: Outer surface 50: Control unit 51A: 1st base 51Aa: 1st contact surface 51Ab: First recess 51B: 2nd base 51Ba: 2nd contact surface 51Bb: Second recess 52A: First ceramic part (periphery) 52B: Second ceramic section 53: Fixing bolt 53a: Head 54: Bolt hole 55: Nut 60: Mold 61: Spout 62:Yudo 70:Protrusion 80:Fixed part 81: Cylindrical part 81a: Bolt hole 82: 1st contact part 83:Second contact part 90:Detection unit 91: Hanging piece 92: Eye bolt 95: Engagement recess 96: Engagement convex part 100: Solid fuel crusher 110: Primary air flow path 120:Powdered fuel supply pipe 160: Mold 200: Boiler 210: Furnace 220: Burner

Claims

1. a crushing roller housed inside a housing, which crushes the solid fuel by sandwiching the solid fuel between itself and a rotating crushing table, and which rotates in response to the rotational force of the crushing table, a support portion supported by the housing so as to be rotatable about a central rotation axis; an annular roller portion that fits onto the outer periphery of the support portion from the outside and crushes the solid fuel between the roller portion and the crushing table; the roller portion has a first portion and a second portion disposed alongside the first portion along an axial direction, which is a direction in which a rotational center axis of the roller portion extends, and fixed to the first portion, and an outer circumferential surface is curved so as to form an arc shape in a cross section in the axial direction, the first portion has a first base portion that fits onto the outer circumferential portion of the support portion from the outside, and a first outer circumferential portion that is integrally formed with the first base portion on the outer circumferential surface of the first base portion and has superior wear resistance to the first base portion, and is provided on one side of a center line in the axial direction; the second portion has a second base portion that fits onto the outer circumferential portion of the support portion from the outside, and a second outer circumferential portion that is integrally formed with the second base portion on the outer circumferential surface of the second base portion and has superior wear resistance to the second base portion, and is provided on the other side of a center line in the axial direction, The first outer peripheral portion and the second outer peripheral portion are provided so as to be line-symmetrical with respect to the center line in a cross section in the axial direction of the crushing roller.

2. the roller portion has a fixed portion including a cylindrical portion provided between the support portion and the first base portion and the second base portion, a first abutment portion extending radially outward from one end of the cylindrical portion in the axial direction and abutting against an end surface of the first base in the axial direction, and a second abutment portion extending radially outward from the other end of the cylindrical portion in the axial direction and abutting against an end surface of the second base in the axial direction, the first base portion is fitted from outside to the outer circumferential portion of the support portion via the cylindrical portion, the second base portion is fitted from the outside to the outer circumferential portion of the support portion via the cylindrical portion, the first contact portion and the second contact portion are fixed by a bolt that passes through the fixing portion, The crushing roller according to claim 1 , wherein the cylindrical portion is formed of a material having a lower hardness than the first base portion and the second base portion.

3. 2. The crushing roller according to claim 1, wherein the first portion and the second portion are fixed to each other by fasteners inserted through linear bolt holes that connect holes formed in the first base portion and holes formed in the second base portion.

4. the first base portion has a first contact surface that contacts the second base portion and a first recess that is recessed from the first contact surface, 4. The crushing roller according to claim 1, wherein the second base portion has a second contact surface that contacts the first contact surface of the first base portion, and a second recess that is recessed from the second contact surface.

5. the first recess and the second recess form a closed space, The crushing roller according to claim 4, wherein a detector for detecting wear of the first outer circumferential portion and / or the second outer circumferential portion is provided in the closed space.

6. the first base portion and / or the second base portion has an engagement recess recessed from a surface that abuts against the support portion, 6. A crushing roller as described in any one of claims 1 to 5, wherein the support portion has an engaging protrusion on a surface that abuts the first base portion and / or the second base portion, the engaging protrusion being accommodated in the engaging recess and engaging with the engaging recess.

7. A crushing roller according to any one of claims 1 to 6; a crushing table that rotates and crushes the solid fuel by sandwiching the solid fuel between itself and the crushing rollers; a housing that accommodates the grinding roller and the grinding table.

8. A method for manufacturing a crushing roller that is housed inside a housing, that sandwiches solid fuel between itself and a rotating crushing table to crush the solid fuel, and that rotates with the rotational force of the crushing table, comprising: The crushing roller is a support portion supported by the housing so as to be rotatable about a central rotation axis; an annular roller portion that fits onto the outer periphery of the support portion from the outside and crushes the solid fuel between the roller portion and the crushing table; the roller portion has a first portion and a second portion disposed alongside the first portion along an axial direction, which is a direction in which a rotational center axis of the roller portion extends, and fixed to the first portion, and an outer circumferential surface is curved so as to form an arc shape in a cross section in the axial direction, the first portion has a first base portion that fits onto the outer circumferential portion of the support portion from the outside, and a first outer circumferential portion that is integrally formed with the first base portion on the outer circumferential surface of the first base portion and has superior wear resistance to the first base portion, and is provided on one side of a center line in the axial direction; the second portion has a second base portion that fits onto the outer circumferential portion of the support portion from the outside, and a second outer circumferential portion that is integrally formed with the second base portion on the outer circumferential surface of the second base portion and has superior wear resistance to the second base portion, and is provided on the other side of a center line in the axial direction, the first outer circumferential portion and the second outer circumferential portion are provided so as to be line-symmetrical with respect to the center line in a cross section in the axial direction, manufacturing the first portion; manufacturing the second portion; and fixing the first portion and the second portion together.

9. 9. The method for manufacturing a crushing roller according to claim 8, wherein the step of manufacturing the second portion and the step of fixing the first portion and the second portion together include placing the first portion manufactured in the step of manufacturing the first portion in a mold having a shape corresponding to the crushing roller, pouring molten metal into the mold, and then cooling the molten metal to manufacture the second portion and fix the first portion and the second portion together.

10. The method for manufacturing a crushing roller according to claim 9, wherein the first portion has a protruding portion that protrudes from a surface on the side of the second portion.

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