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

Abstract

A pulverizing roller (13) includes a support portion rotatably supported with respect to a housing, and a ring-shaped roller portion (49) fixed to the support portion and pulverizing solid fuel between the roller portion (49) and a pulverizing table. The roller portion (49) includes a base portion (51) fixed to a journal housing (48), and a ceramic portion (52) provided to an outer peripheral surface of the base portion (51), the ceramic portion (52) having a different linear expansion coefficient from that of the base portion (51) and having superior wear resistance to that of the base portion (51), and a boundary surface (53) between the base portion (51) and the ceramic portion (52) in a cross section of the roller portion (49) cut by a plane including an extension direction of a rotational center axis of the roller portion (49) has a curved portion (53a) protruding toward an outer peripheral surface (49a) of the roller portion (49) at an end surface (13b) side close to a maximum wear point (P1) of the outer peripheral surface (49a) of the roller portion (49) compared to the boundary surface (53).

Description

Technical Field

[0001] This disclosure relates to a crushing roller, a solid fuel crushing apparatus, and a method for manufacturing the crushing roller. Background Technology

[0002] Traditionally, solid fuels such as biomass fuels or coal are pulverized into fine powder within a predetermined particle size range using a mill and then supplied to a combustion unit. The mill pulverizes the solid fuel fed into the pulverizing platform by clamping it between the platform and the pulverizing rollers. A classifier separates the pulverized solid fuel within the predetermined particle size range. Primary air, supplied from the outer periphery of the pulverizing platform, is then used to transport the pulverized fuel to a boiler for combustion in the combustion unit. In thermal power generation equipment, steam is generated through heat exchange with the combustion gases 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] As a grinding roller installed in a mill, there are known ceramic-embedded grinding rollers (for example, Patent Document 1) in which a ceramic with high wear resistance is embedded in the part that comes into contact with solid fuel. Compared with conventional grinding rollers, such ceramic-embedded grinding rollers have superior wear resistance and allowable wear, and can achieve a long service life.

[0004] Patent Document 1 discloses a crushing roller having a base made of high-chromium cast iron that fits into a journal housing and a hardened portion that partially includes a ceramic component disposed on the outer peripheral surface of the base.

[0005] Existing technical documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-11164 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In manufacturing a ceramic-embedded crushing roller, molten metal is first poured into the mold while a ceramic block is positioned at a predetermined location within the mold. Then, the metal within the mold is cooled and solidified. This process creates a ceramic-embedded crushing roller in which the ceramic portion (containing ceramic) and the base portion (not containing ceramic) are integrally fixed.

[0009] When cooling the metal within the mold, there are concerns about damage caused by thermal shrinkage. The coefficient of linear expansion of the ceramic part is smaller than that of the metal within the mold. Therefore, the shrinkage rate of the ceramic part during cooling is smaller than that of the base. Consequently, the shrinkage amounts of the ceramic part and the base differ during cooling. At this point, since the ceramic part and the base are integrated, the base attempts to shrink the ceramic part, while the ceramic part attempts to suppress the shrinkage of the base. As a result, thermal stress acts on both the base and the ceramic part, potentially damaging the crushing roller. Thus, ceramic-embedded crushing rollers may be damaged during manufacturing due to the difference in the coefficients of linear expansion between the ceramic part and the base. This could lead to a deterioration in the yield rate during the manufacture of crushing rollers.

[0010] If the rigidity of a component is reduced, the component will elongate well. Therefore, the stress generated when the same displacement is applied is suppressed to a lower level, resulting in less thermal stress. Thus, to suppress thermal stress in a ceramic-embedded crushing roller, it is conceivable to reduce the thickness of the ceramic portion and decrease its rigidity. However, if the ceramic portion is thinned, there is a problem of reduced wear resistance and allowable wear of the crushing roller, leading to a shorter roller lifespan.

[0011] Given this situation, it is desirable to improve the yield rate in manufacturing crushing rollers and to extend their service life.

[0012] This disclosure is made in view of the following circumstances, and its object is to provide a crushing roller, a solid fuel crushing apparatus, and a method for manufacturing the crushing roller that can improve the yield of the crushing roller during manufacturing and extend the service life of the crushing roller.

[0013] Methods for solving problems

[0014] To solve the above-mentioned problems, the crushing roller, solid fuel crushing apparatus, and manufacturing method of the crushing roller disclosed herein employ the following means.

[0015] According to one aspect of the present disclosure, a crushing roller is housed inside a housing. Solid fuel is sandwiched between the crushing roller and a rotating crushing table to crush the solid fuel. The crushing roller is rotated by a rotational force from the crushing table. The crushing roller includes: a support portion supported so as to be able to rotate relative to the housing; and an annular roller portion fixed to the support portion, which crushes the solid fuel between the roller portion and the crushing table. The roller portion has: a base portion fixed to the support portion; and an outer peripheral portion disposed on the outer peripheral surface of the base portion. The linear expansion coefficient of the outer peripheral portion is different from that of the base portion, and the wear resistance of the outer peripheral portion is superior to that of the base portion. In a cross-section of the roller portion cut along a surface including the extension direction of the rotation center axis of the roller portion, the boundary surface between the base portion and the outer peripheral portion has a curved portion at the end face near the maximum wear point (P1) that bends in a manner protruding toward the outer peripheral surface of the roller portion. The maximum wear point is the point on the outer peripheral surface of the roller portion that is most easily worn.

[0016] In another embodiment of the manufacturing method of the crushing roller disclosed herein, the crushing roller is housed inside a housing. Solid fuel is sandwiched between the crushing roller and a rotating crushing table to crush the solid fuel. The crushing roller is rotated by the rotational force from the crushing table. The crushing roller includes: a support portion fixed to the housing; and an annular roller portion rotatably supported on the support portion about the support portion. Solid fuel is crushed between the roller portion and the crushing table. The roller portion includes: a base portion supported on the support portion; and an outer peripheral portion disposed on the outer peripheral surface of the base portion. The outer peripheral portion has linear expansion. The coefficient of thermal expansion is different from that of the base, and the wear resistance of the outer periphery is better than that of the base. When the roller is cut in the cross section with the surface extending in the direction including the rotation center axis of the roller, the boundary surface between the base and the outer periphery has a curved portion that bends toward the outer periphery of the roller at the end face side near the maximum wear point (P1), which is the point on the outer periphery of the roller that is most easily worn. The manufacturing method of the crushing roller includes a step of integrally forming the base and the outer periphery by casting.

[0017] Invention Effects

[0018] It can improve the yield rate when manufacturing crushing rollers and extend the service life of crushing rollers. Attached Figure Description

[0019] Figure 1 This is a structural diagram showing the solid fuel pulverizing apparatus and boiler according to the first embodiment of this disclosure.

[0020] Figure 2This is a schematic side view of a crushing roller installed in a solid fuel crushing apparatus according to the first embodiment of this disclosure.

[0021] Figure 3 This is a cross-sectional view of the main part of the crushing roller according to the first embodiment of this disclosure.

[0022] Figure 4 This is a cross-sectional view of the main part of the crushing roller according to the first embodiment of this disclosure, and is a diagram showing the wear state of the roller.

[0023] Figure 5 This is a schematic diagram showing the mold for manufacturing the crushing roller according to the first embodiment of this disclosure.

[0024] Figure 6 yes Figure 3 A diagram of a variation.

[0025] Figure 7 yes Figure 3 A diagram of a variation.

[0026] Figure 8 yes Figure 3 A diagram of a variation. Detailed Implementation

[0027] Hereinafter, an embodiment of the crushing roller, solid fuel crushing apparatus, and manufacturing method of the crushing roller of the present disclosure will be described with reference to the accompanying drawings.

[0028] [First Implementation]

[0029] Hereinafter, a first embodiment of the present disclosure will be described with reference to the accompanying drawings. The power generation equipment 1 of this embodiment includes a solid fuel pulverizing device 100 and a boiler 200.

[0030] In the following explanations, "above" refers to the direction above the plumb line, and "upper part" and "upper surface" refer to the portion above the plumb line. Similarly, "below" refers to the portion below the plumb line. The plumb line direction is not strictly defined and includes errors.

[0031] As an example, the solid fuel pulverizing apparatus 100 of this embodiment is an apparatus that pulverizes solid fuels such as biomass fuel or coal to generate micro-powdered fuel and supplies it to the burner (combustion device) 220 of the boiler 200.

[0032] Figure 1 The power generation equipment 1 shown includes a solid fuel pulverizer 100 and a boiler 200. It has one solid fuel pulverizer 100, but it can also be configured as a system with multiple solid fuel pulverizers 100 corresponding to multiple burners 220 of a boiler 200.

[0033] The solid fuel pulverizing apparatus 100 of this embodiment includes: a mill (pulverizing unit) 10, a hopper (storage unit) 21, a coal feeder (fuel feeder) 25, an air supply unit (gas supply unit for conveying) 30, a status detection unit 40, and a control unit 50.

[0034] The mill 10 that crushes solid fuels such as coal or biomass fuel supplied to boiler 200 into fine powder, i.e., fine powder fuel, can be in the form of crushing only coal, crushing only biomass fuel, or crushing biomass fuel and coal together.

[0035] Here, biomass fuel refers to renewable organic resources derived from living organisms, such as thinned timber, waste wood, driftwood, grass, waste, sludge, tires, and recycled fuels (pellet or fragments) made from them, and is not limited to the substances mentioned herein. Biomass fuel absorbs carbon dioxide during the growth of biomass, thus achieving carbon neutrality by preventing the emission of carbon dioxide, a greenhouse gas on Earth, and therefore its utilization has been the subject of various studies.

[0036] The mill 10 includes: a housing 11, a crushing table 12, a crushing roller 13, a reducer (drive transmission unit) 14, a mill motor (drive unit) 15 connected to the reducer 14 and driving the crushing 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.

[0037] The housing 11 is formed as a cylinder extending in the vertical direction and is a box housing the crushing table 12, the crushing roller 13, the rotary classifier 16, and the coal supply pipe 17.

[0038] A coal supply pipe 17 is installed at the center of the top 42 of the housing 11. The coal supply pipe 17 supplies solid fuel from the hopper 21 via the coal feeder 25 into the housing 11. It is arranged vertically at the center of the housing 11 and extends into the interior of the housing 11 at its lower end.

[0039] A speed reducer 14 is provided near the bottom part 41 of the housing 11, and the grinding table 12, which rotates by the driving force transmitted from the mill motor 15 connected to the speed reducer 14, is configured to rotate freely.

[0040] The crushing table 12 is a circular component when viewed from above, and is arranged facing the lower end of the coal supply pipe 17. The upper surface of the crushing table 12 may, for example, be a sloping shape with a low center that increases towards the outer edge, and bends upward at the outer periphery. The coal supply pipe 17 supplies solid fuel (e.g., coal or biomass fuel in this embodiment) from above to the crushing table 12 below, and the crushing table 12 clamps the supplied solid fuel between itself and the crushing roller 13 for crushing.

[0041] When solid fuel is fed from the coal supply pipe 17 into the center of the crushing table 12, the centrifugal force generated by the rotation of the crushing table 12 guides the solid fuel to the outer periphery of the crushing table 12, where it is crushed between the crushing table 12 and the crushing roller 13. The crushed solid fuel is then blown upward by the conveying gas (hereinafter referred to as primary air) from the conveying gas path (hereinafter referred to as primary air) 110 and guided towards the rotary classifier 16.

[0042] An outlet (not shown) is provided on the outer periphery of the pulverizing table 12, through which primary air flowing in from the primary air flow path 110 exits into the space above the pulverizing table 12 within the housing 11. A gyratory blade (not shown) is provided at the outlet to impart a gyratory force to the primary air blown out from the outlet. The primary air imparted with gyratory force by the gyratory blade becomes an airflow with a gyratory velocity component, conveying the pulverized solid fuel on the pulverizing table 12 to the rotary classifier 16 located above within the housing 11. Furthermore, solid fuel particles larger than a predetermined particle size in the pulverized solid fuel are classified by the rotary classifier 16, or, if they do not reach the rotary classifier 16, fall back onto the pulverizing table 12 and are pulverized again between the pulverizing table 12 and the pulverizing roller 13.

[0043] The crushing roller 13 is a rotating body that crushes solid fuel supplied from the coal supply pipe 17 to the crushing table 12. The crushing roller 13 presses against the upper surface of the crushing table 12 and works with the crushing table 12 to crush the solid fuel.

[0044] exist Figure 1 In this example, only one crushing roller 13 is shown as an example, but multiple crushing rollers 13 are arranged at certain intervals in the circumferential direction in a manner that presses against the upper surface of the crushing table 12. For example, three crushing rollers 13 are arranged at equal intervals in the circumferential direction at 120° intervals on the outer periphery. In this case, the portions of the three crushing rollers 13 that contact the upper surface of the crushing table 12 (the pressing portions) are equidistant from the rotational center axis of the crushing table 12.

[0045] The crushing roller 13 is able to swing up and down and move through the journal head 43, and is supported so as to be nearly and freely separated from the upper surface of the crushing table 12. When the crushing roller 13 is in contact with the solid fuel on the upper surface of the crushing table 12, it rotates along with the crushing table 12 due to the rotational force acting on it. When solid fuel is supplied from the coal supply pipe 17, the solid fuel is pressed and crushed between the crushing roller 13 and the crushing table 12. This pressing force is called the crushing load.

[0046] The middle portion of the support arm 44 of the journal head 43 is supported on the side of the housing 11 by a support shaft 45 along the horizontal direction, so that the crushing roller 13 can swing and move vertically around the support shaft 45. Furthermore, a pressing device (crushing load application part) 46 is provided at the upper end of the support arm 44 on the vertical side. 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., by pressing 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 working oil supplied from a hydraulic device (not shown) located outside the mill 10. Alternatively, the crushing load can also be applied by the restoring force of a spring (not shown).

[0047] The reducer 14 is connected to the mill motor 15 and transmits the driving force of the mill motor 15 to the crushing table 12, causing the crushing table 12 to rotate around the central axis.

[0048] A rotary classifier (classification section) 16 is disposed on the upper part of the housing 11 and has a hollow, inverted conical shape. The rotary classifier 16 has a plurality of blades 16a extending in the vertical direction on its outer periphery. Each blade 16a is arranged around the central axis of the rotary classifier 16 at a predetermined interval (equal interval).

[0049] The rotary classifier 16 is a device for classifying solid fuel (hereinafter, the pulverized solid fuel is referred to as "pulverized fuel") pulverized by the pulverizing table 12 and the pulverizing roller 13 into fuel with a particle size larger than a predetermined particle size (e.g., 70 μm to 100 μm in the case of coal) (hereinafter, pulverized fuel exceeding the predetermined particle size is referred to as "coarse fuel") and fuel with a particle size smaller than the predetermined particle size (hereinafter, pulverized fuel smaller than the predetermined particle size is referred to as "fine fuel"). The rotary classifier 16 is given rotational driving force by a classifier motor 18 controlled by the control unit 50, and rotates around the coal supply pipe 17 with a cylindrical shaft (not shown) extending in the vertical direction along the housing 11 as the center.

[0050] Alternatively, a fixed classifier may be used as the grading unit, which has a fixed hollow inverted conical shell and multiple fixed swirling blades that replace the blades 16a at the outer periphery of the shell.

[0051] The pulverized fuel arriving at the rotary classifier 16 is relatively balanced by the centrifugal force generated by the rotation of the blades 16a and the centripetal force generated by the airflow of the primary air. Larger diameter coarse fuel is knocked off by the blades 16a and returns to the pulverizing table 12 for further pulverization, while fine fuel is guided to the outlet port 19 located at the top 42 of the housing 11. The fine fuel classified by the rotary classifier 16, together with the primary air, is discharged from the outlet port 19 into the fine fuel supply path (fine fuel supply pipe) 120 and supplied to the burner 220 of the boiler 200.

[0052] The coal supply pipe (fuel supply section) 17 is installed by extending its lower end into the interior of the housing 11 in a vertical direction through the top 42 of the housing 11, and supplies solid fuel from the upper part of the coal supply pipe 17 to the center of the crushing worktable 12. A coal feeder 25 is connected to the upper end of the coal supply pipe 17 and is supplied with solid fuel.

[0053] The coal feeder 25 is connected to the hopper 21 via a downcomer section 22 extending vertically from the lower end of the hopper 21. A valve (call gate, not shown) for switching the discharge state of solid fuel from the hopper 21 may also be installed midway through the downcomer section 22. The coal feeder 25 includes a conveyor section 26 and a coal feeder motor 27. The conveyor section 26, for example, is a belt conveyor, which, driven by the coal feeder motor 27, conveys the solid fuel discharged from the lower end of the downcomer section 22 to the upper part of the coal feed pipe 17 and feeds it into the mill 10. The amount of solid fuel supplied to the mill 10 is controlled by adjusting the speed of the belt conveyor in the conveyor section 26, for example, according to a signal from the control unit 50.

[0054] Typically, inside the mill 10, primary air is supplied to deliver the pulverized fuel to the burner 220 at a higher pressure than that of the coal feeder 25 and the hopper 21. The interior of the feed pipe section 22, which connects the hopper 21 to the coal feeder 25, is in a fuel-stacked state. Through this solid fuel layer, a seal (material seal) is ensured from the mill 10 to the hopper 21 to prevent backflow of primary air and pulverized fuel.

[0055] The air supply unit 30 is a device that supplies primary air, used to dry pulverized fuel and to convey it to the rotary classifier 16, into the interior of the housing 11.

[0056] In order to properly adjust the flow rate and temperature of the primary air blown into the interior of the housing 11, in this embodiment, the air supply unit 30 includes: a primary air fan (PAF) 31, a hot air flow path 30a, a cold air flow path 30b, a hot air damper 30c, and a cold air damper 30d.

[0057] In this embodiment, the hot air flow path 30a supplies a portion of the air delivered from the primary air fan 31 as heated hot air by passing it through an air preheater (heat exchanger) 34. A hot air damper 30c is provided in the hot air flow path 30a. The opening degree of the hot air damper 30c is controlled by the control unit 50. The flow rate of the hot air supplied from the hot air flow path 30a is determined based on the opening degree of the hot air damper 30c.

[0058] The cold air flow path 30b supplies a portion of the air delivered from the primary air fan 31 as ambient temperature cold air. A cold air damper 30d is provided in the cold air flow path 30b. The opening degree of the cold air damper 30d is controlled by the control unit 50. The flow rate of the cold air supplied from the cold air flow path 30b is determined based on the opening degree of the cold air damper 30d.

[0059] In this embodiment, the primary air flow rate is the sum of the flow rates of the hot air supplied from the hot air flow path 30a and the cold air supplied from the cold air flow path 30b. The temperature of the primary air is determined by the mixing ratio of the hot air supplied from the hot air flow path 30a and the cold air supplied from the cold air flow path 30b, and is controlled by the control unit 50.

[0060] Alternatively, the oxygen concentration in the primary air supplied from the primary air path 110 to the interior of the casing 11 can be adjusted by, for example, using a gas recirculation fan (not shown) to guide and mix a portion of the combustion gases discharged from the boiler 200 with the hot air supplied from the hot air path 30a. By adjusting the oxygen concentration in the primary air, for example when using a solid fuel with high ignition (easy to ignite), ignition of the solid fuel can be suppressed in the path from the mill 10 to the burner 220.

[0061] In this embodiment, the data measured or detected by the state detection unit 40 of the mill 10 is sent to the control unit 50. The state detection unit 40 in this embodiment is, for example, a differential pressure measuring unit that measures the pressure difference between the pressure at the portion of primary air flowing from the primary air flow path 110 into the interior of the housing 11 and the pressure at the outlet port 19 of the primary air and the fine fuel discharged from the interior of the housing 11 into the fine fuel supply pipe 120. The increase or decrease of this differential pressure in the mill 10 corresponds to the increase or decrease of the circulation amount of the pulverized fuel circulating between the vicinity of the rotary classifier 16 and the vicinity of the pulverizing table 12 inside the housing 11 due to the classification effect of the rotary classifier 16. That is, by adjusting the rotational speed of the rotary classifier 16 according to the differential pressure of the mill 10, the amount and particle size range of the fine fuel discharged from the outlet port 19 can be adjusted. Therefore, the particle size of the fine fuel can be maintained within a range that does not affect the combustibility of the solid fuel in the burner 220, and the amount of fine fuel corresponding to the amount of solid fuel supplied to the mill 10 can be stably supplied to the burner 220 installed in the boiler 200.

[0062] Furthermore, the state detection unit 40 in this embodiment is, for example, a temperature measuring mechanism, which detects the temperature of the primary air supplied to the interior of the housing 11 (mill inlet primary air temperature) and the temperature of the mixture of primary air and pulverized fuel at the outlet port 19 (mill outlet primary air temperature), and controls the air supply unit 30 in a manner that does not exceed their respective upper limit temperatures. Each upper limit temperature is determined taking into account factors such as the ignition possibility corresponding to the properties of the solid fuel. In addition, the primary air is cooled inside the housing 11 by drying the pulverized fuel while being transported; therefore, the primary air temperature at the mill inlet is, for example, from room temperature to approximately 300 degrees Celsius, and the primary air temperature at the mill outlet is, for example, from room temperature to approximately 90 degrees Celsius.

[0063] The control unit 50 is a device that controls the various parts of the solid fuel pulverizing device 100.

[0064] The control unit 50 can also transmit drive instructions to the mill motor 15 to control the rotation speed of the crushing table 12.

[0065] The control unit 50, for example, transmits a drive instruction to the classifier motor 18 to control the rotational speed of the rotary classifier 16 to adjust the classification performance. This allows the particle size of the fine fuel to be maintained within a range that does not affect the combustibility of the solid fuel in the burner 220, and the fine fuel to be stably supplied to the burner 220 in an amount corresponding to the amount of solid fuel supplied to the mill 10.

[0066] In addition, the control unit 50 can, for example, adjust the amount of solid fuel supplied to the mill 10 (coal supply) by transmitting a drive instruction to the coal feeder motor 27.

[0067] Furthermore, the control unit 50 can adjust the primary air flow rate and temperature by controlling the opening of the hot air damper 30c and the cold air damper 30d by transmitting an opening instruction to the air supply unit 30. Specifically, the control unit 50 controls the opening of the hot air damper 30c and the cold air damper 30d so that the primary air flow rate supplied to the interior of the housing 11 and the primary air temperature at the outlet port 19 (mill outlet primary air temperature) are predetermined values ​​set corresponding to the coal supply quantity for each type of solid fuel. In addition, the temperature at the mill inlet (mill inlet primary air temperature) can also be controlled to adjust the primary air temperature.

[0068] The control unit 50 is composed of, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and a computer-readable storage medium. As an example, a series of processes for implementing various functions are stored in the storage medium in the form of a program. The CPU reads this program into RAM, etc., and performs information processing and arithmetic to achieve various functions. Alternatively, the program can be pre-installed on ROM or other storage media, provided in its current state stored on a computer-readable storage medium, or distributed via a wired or wireless communication unit. Computer-readable storage media include disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memories, etc. Furthermore, HDDs can be replaced by solid-state drives (SSDs).

[0069] Next, a boiler 200 that generates steam by burning finely powdered fuel supplied from a solid fuel pulverizing device 100 will be described. The boiler 200 includes a furnace 210 and a burner 220.

[0070] Burner 220 is a device that uses a mixture of pulverized fuel supplied from pulverized fuel supply pipe 120 and primary air, and secondary air supplied by heating air (external gas) delivered from forced draft fan (FDF) 32 using air preheater 34, to burn the pulverized fuel and form a flame. Combustion of the pulverized fuel takes place inside furnace 210, and the high-temperature combustion gases are discharged to the outside of boiler 200 after passing through heat exchangers such as evaporator, superheater, and fuel saver (not shown).

[0071] Combustion gases discharged from boiler 200 undergo predetermined treatment in environmental devices (omitted from illustrations in denitrification, dust collection, and desulfurization units, etc.), and exchange heat with primary and secondary air in air preheater 34. The gases are then guided to the chimney (omitted from illustration) via induced draft fan (IDF) 33 and released to the outside. Air heated by the combustion gases in air preheater 34 and supplied from primary air fan 31 is then fed into the aforementioned hot gas flow path 30a.

[0072] The water supplied to each heat exchanger of boiler 200 is heated in the coal saver (not shown), and then further heated by the evaporator (not shown) and superheater (not shown) to generate high-temperature and high-pressure superheated steam, which is then delivered to the steam turbine (not shown) which serves as the power generation unit to drive the steam turbine to rotate, thereby driving the generator (not shown) connected to the steam turbine to rotate and generate electricity, thus constituting power generation equipment 1.

[0073] Next, refer to Figures 1 to 5 The details of the crushing roller 13 in this embodiment will be described in detail.

[0074] like Figure 1 and Figure 2 As shown, each crushing roller 13 is supported on the housing 11 via a journal shaft 47, a journal head 43, and a support shaft 45, in a manner that allows it to rotate around the rotation center axis C2. The journal shaft 47 extends downward from near the side of the housing 11 toward the center of the housing 11. The base end of the journal shaft 47 (the end on the side of the housing 11) is fixed to the journal head 43. In addition, the crushing roller 13 is rotatably supported at the front end of the journal shaft 47 (the end on the center of the mill 10) via a bearing (not shown). That is, the crushing roller 13 is supported and can rotate in a state where its upper part is inclined to a position closer to the center of the housing 11 than its lower part is vertically above the crushing table 12.

[0075] like Figure 2 As shown, the crushing roller 13 includes: a journal housing (support part) 48, which is rotatably supported on the front end of the journal shaft 47 about the rotation center axis C2; and a generally annular roller part 49, which is externally fitted into the journal housing 48. The journal housing 48 is provided to cover the front end of the journal shaft 47, and its outer peripheral surface is formed into a cylindrical shape.

[0076] Figure 3 and Figure 4 The main part of the cross section (hereinafter referred to as the "axial direction section") when the roller 49 is cut along the extension direction of the rotation center axis C2 of the roller 49.

[0077] like Figure 3 and Figure 4 As shown, the roller portion 49 includes: a high-chromium cast iron base 51 that fits into the journal housing 48; and a ceramic portion (outer peripheral portion) 52, which partially includes a ceramic component disposed on the outer peripheral surface 51a of the base 51. That is, the roller portion 49 of this embodiment is a so-called ceramic-embedded high-chromium cast iron roller.

[0078] The outer peripheral surface 49a of the roller portion 49 is approximately annular, and the inner peripheral surface is approximately cylindrical. An end face connects the outer peripheral surface 49a to the inner peripheral surface. In the axial direction section, the outer peripheral surface 49a of the roller portion 49 is curved in an arc shape centered at the center point CP. In the axial direction section, the outer peripheral surface 49a of the roller portion 49 is a straight line parallel to the rotation center axis C2.

[0079] The base 51 is supported on the journal housing 48. The base 51 is formed in a generally annular shape. Furthermore, the base 51 is fitted into the journal housing 48 such that its inner circumferential surface contacts the outer circumferential surface of the journal housing 48. A ceramic part 52 is fixed to the outer periphery of the annular base 51. The ceramic part 52 is provided over approximately the entire circumferential area of ​​the base 51. That is, the ceramic part 52 is formed in a generally annular shape. The ceramic part 52 does not cover the entire area of ​​the outer circumferential surface 51a of the base 51, but rather covers the base end side of the roller part 49 in the outer circumferential surface 51a of the base 51. Here, the base end side refers to the side of the journal shaft 47 connecting the crushing roller 13, which is indicated in the radial direction of the crushing table 12 as the outer circumferential side, and the front end side refers to the side indicating the rotation center axis C1 in the radial direction of the crushing table 12 (see reference). Figure 1 The base end side of the outer peripheral surface 49a (the surface for crushing solid fuel) of the roller 49 is formed by the outer peripheral surface 52a of the ceramic part 52, and the front end side (the side opposite to the base end side) is formed by the outer peripheral surface 51a of the base 51.

[0080] The ceramic part 52 contains ceramic components, therefore its coefficient of linear expansion is smaller than that of the high-chromium cast iron base 51. Furthermore, the ceramic part 52 exhibits superior wear resistance compared to the base 51. The materials of the base 51 and the ceramic part 52 are not limited to those described above.

[0081] Figure 2 and Figure 4 The dashed line L1 in the figure represents the wear progression of the roller 49 as it pulverizes solid fuel by the mill 10. That is, in this embodiment, a portion P1 (hereinafter referred to as "maximum wear point P1") of the roller 49 on the base end side (i.e., the side opposite to the front end side) is more worn than other portions. As described above, the base end side refers to the outer periphery of the pulverizing table 12 in the radial direction, and the front end side refers to the rotation center axis C1 of the pulverizing table 12 (see reference). Figure 1 ) side. Additionally, Figure 2 The dashed line L2 in the figure represents the wear progression pattern of the crushing table 12. Additionally, in Figure 2 and Figure 4 In the figure, the maximum wear point before wear is indicated by the reference numeral "P1", and the maximum wear point under the actual wear progression state is indicated by the reference numeral "P1′". In other words, the maximum wear point P1 before wear is the point where wear is expected to progress most easily.

[0082] The point of maximum wear, P1, is located on the outer peripheral surface 49a of the roller portion 49, at a predetermined angle θ1 relative to the center line C3 at the center point CP towards the base end. The center line C3 is a line orthogonal to the rotation center axis C2 and passing through the center portion of the extension direction of the rotation center axis C2. More specifically, it is the point where the line L3, forming the predetermined angle θ1 with the center line C3, intersects the outer peripheral surface 49a. In this embodiment, the angle θ1 is set to 8 degrees, but it is not limited to 8 degrees. The angle θ1 only needs to be within the range of 3 to 13 degrees (a range of ±5 degrees from 8 degrees).

[0083] Furthermore, in this embodiment, the thickness of the ceramic part 52 is the thickest in the axial direction section of the portion through which the line L3 forms a predetermined angle θ1 with the center line C3 passes.

[0084] Next, the boundary surface 53 between the base 51 and the ceramic part 52 in the axial direction section will be described. The boundary surface 53 is formed by the surface where the outer peripheral surface 51a of the base 51 contacts the inner surface of the ceramic part 52. The boundary surface 53 has approximately the same shape throughout the entire circumferential region, that is, in any axial direction section.

[0085] like Figure 3 As shown, the boundary surface 53 has a curved portion 53a on the end face 13b side (base end side) that is curved in a manner that protrudes toward the outer peripheral surface 49a of the roller portion 49, compared to the point of greatest wear, P1, which is the most easily worn point on the outer peripheral surface 49a of the roller portion 49. In other words, the curved portion 53a is curved in a manner that reduces the thickness of the ceramic portion 52.

[0086] The bend 53a is a straight line connecting the starting point 53as and the ending point 53ae of the bend 53a. Figure 3 The point P2, where the longest distance from the double-dotted line L5 to the bend 53a is (in other words, the point where the thickness of the ceramic portion 52 is minimized by providing the bend 53a), is located on the end face 13b side (base end side) closer to the maximum wear point P1 of the roller portion 49. That is, in this embodiment, as... Figure 3 As shown, P2 is located at a position A1 longer than P1 on the end face 13b side (base end side).

[0087] In addition, the radius of curvature of the curved portion 53a is, for example, more than 10% (approximately 10 times) of the radius of curvature of the outer peripheral surface 49a of the roller portion 49.

[0088] Furthermore, the boundary surface 53 has: a straight portion 53b, which connects to the end of the curved portion 53a at its front end and extends in a straight line; and a bent portion 53c, which bends and extends from the end of the straight portion 53b at its front end toward the outer peripheral surface 49a. The straight portion 53b and the curved portion 53a are smoothly connected. Smooth connection means that there are no steps or the like at the connection between the straight portion 53b and the curved portion 53a.

[0089] Furthermore, in the boundary surface 53, the end point 53e on the opposite side of the end face 13b (base end side), i.e., the starting point 53s, is located on the outer peripheral surface 49a side of the roller portion 49, compared to the end point 53s on the end face 13b side (base end side). That is, in this embodiment, as... Figure 3 As shown, the endpoint 53e is located at a position A2 on the outer periphery 49a side, which is closer to the starting point 53s.

[0090] In addition, the starting point 53s of the boundary surface 53 is determined by the buoyancy of the ceramic block CB (ceramic part 52) ​​during the manufacturing of the roller part 49, as described later.

[0091] In addition, such as Figure 4 As shown, the curved portion 53a is located on the line connecting the starting point 53s and line L3 (a line forming a predetermined angle θ1 with the center line C3) to the boundary surface 53 (hereinafter referred to as "intersection point P3"). Figure 4 The position of the ceramic part 52 is near the outer peripheral surface 49a (the dashed line L6 in the diagram). That is, compared with the case where the boundary surface 53 is set as the dashed line L6, the thickness of the ceramic part 52 is thinner at the base end side (starting point 53s side) compared to the intersection point P3.

[0092] Furthermore, the boundary surface 53 is located on the front end side (end point 53e side) of the intersection point P3, and on the journal housing 48 side of the extension line (dashed line L7) of the dashed line L6. That is, compared with the case where the boundary surface 53 is set as dashed line L7, the thickness of the ceramic part 52 is thicker on the front end side (end point 53e side) of the intersection point P3.

[0093] Next, refer to Figure 5 The method for manufacturing the roller section 49 will now be explained. Figure 5 In this context, UP represents "up" in the vertical direction.

[0094] First, ceramic blocks CB (see reference) that constitute a part of the ceramic part 52 are manufactured by shaping ceramic particles into a block shape (the shape corresponding to the ceramic part 52). Figure 5 The ceramic block is formed by bonding together particle-like ceramic particles, creating numerous gaps between them. The shape of the outer peripheral surface of the ceramic block CB is similar to the outer peripheral surface 52a of the ceramic part 52 (see reference). Figure 4 The shapes of (etc.) are roughly the same.

[0095] Next, the manufactured ceramic block CB is placed in a predetermined position within the mold 60. Then, molten metal is allowed to flow into the mold 60 from the gate 61 through the runner 62. Thus, the mold 60 is filled with molten metal (refer to arrow m). At this point, the ceramic block CB is lighter than the molten metal, therefore, as... Figure 5 As shown, the ceramic block CB is pressed against a predetermined position on the inner circumferential surface of the mold 60 by buoyancy (refer to arrow b). Specifically, the upper surface CBa of the ceramic block CB (the surface corresponding to the end face of the base end of the ceramic part 52) ​​is pressed against the top surface of the mold 60, and this CBa supports the ceramic block CB within the mold 60. Additionally, molten metal flows into the gaps between the ceramic particles formed inside the ceramic block CB.

[0096] Next, the molten metal is cooled and solidified. This completes the integral formation of the roller portion 49, which integrates the ceramic part 52 (which incorporates metal into the ceramic particles inside the ceramic block CB, providing excellent wear resistance) and the base portion 51 (formed solely from the solidified metal).

[0097] Thus, the roller portion 49 of this embodiment is manufactured by casting the base portion 51 and the ceramic portion 52 together.

[0098] According to this embodiment, the following effects are achieved.

[0099] In this embodiment, the boundary surface 53 between the base 51 and the ceramic part 52 in the axial direction section of the roller part 49 has a curved portion 53a at the end face side (base end side) that bends in a manner that protrudes toward the outer peripheral surface 49a of the roller part 49 compared to the maximum wear point P1.

[0100] Therefore, the thickness of the ceramic part 52 decreases within the range of the inner circumferential surface of the curved portion 53a. This reduces the rigidity of the ceramic part 52. Consequently, the ceramic part 52 readily absorbs thermal stress between the base 51 and the ceramic part 52, thus suppressing damage to the ceramic part 52 caused by the difference in linear expansion coefficients. This improves the yield rate when manufacturing the crushing roller 13, thereby reducing manufacturing costs.

[0101] On the other hand, at the point of maximum wear P1, the thickness of the ceramic part 52 does not decrease, thus maintaining the wear resistance of the crushing roller 13. Therefore, it is possible to suppress the shortening of the lifespan of the crushing roller 13 and extend its lifespan.

[0102] Thus, in this embodiment, the yield rate of manufacturing the crushing roller 13 can be improved, and the lifespan of the crushing roller 13 can be extended.

[0103] Furthermore, in this embodiment, the boundary surface 53 has a straight portion 53b. Therefore, compared to a structure where the entire boundary surface 53 is a curved portion 53a, the roller portion 49 can be manufactured more easily. The effects will be explained in detail. Because the ceramic block CB is manufactured by casting, in the case of a curved portion 53a, the portion of the mold used for the ceramic block CB corresponding to the curved portion 53a needs to be cut into a curved surface. However, compared to cutting it into a flat surface, cutting it into a curved surface is more difficult. Therefore, compared to a structure where the entire boundary surface 53 is a curved portion 53a, the portion cut into a curved surface can be reduced, thus making it easier to manufacture the ceramic block CB. Furthermore, it makes it easier to manufacture the roller portion 49.

[0104] Furthermore, in this embodiment, the straight portion 53b and the curved portion 53a are smoothly connected. Therefore, when thermal stress acts on the base portion 51 and the ceramic portion 52, stress concentration is less likely to occur. Thus, damage to the ceramic portion 52 caused by the difference in linear expansion coefficients can be suppressed.

[0105] In addition, a smooth connection refers to a connection in a manner in which there are no steps or other obstacles at the connection between the straight part 53b and the curved part 53a.

[0106] If the radius of curvature of the bend 53a is too small, stress concentration will occur in the bend 53a, which may become the starting point of damage caused by thermal stress.

[0107] On the other hand, in this embodiment, the radius of curvature of the bent portion 53a is, for example, 10% or more relative to the radius of curvature of the outer peripheral surface 49a of the roller portion 49. This prevents the radius of curvature of the bent portion 53a from becoming too small, thus reducing the likelihood of stress concentration. Consequently, damage to the ceramic portion 52 caused by the difference in linear expansion coefficients can be suppressed.

[0108] Furthermore, as wear progresses on roller 49, it is sometimes used in reverse. That is, roller 49 is sometimes temporarily removed from journal housing 48, the base end side and the front end side are swapped, and roller 49 is then reinstalled on journal housing 48 for use. In this case, the point of maximum wear becomes a position symmetrical about the center line C3. More specifically, as... Figure 4 As shown, the point P4 where line L4, which is the line symmetrical to line L3 forming a predetermined angle θ1 with center line C3, intersects with the outer peripheral surface 49a of roller 49.

[0109] In this embodiment, the boundary surface 53 is located on the journal housing 48 side of the extension line (dashed line L7) of the dashed line L6, closer to the front end side (end point 53e side) of the intersection point P3. That is, compared with the case where the boundary surface 53 is set as dashed line L7, the thickness of the ceramic part 52 is thicker on the front end side (end point 53e side) of the intersection point P3. As a result, even when the roller part 49 is used in reverse, the thickness of the ceramic layer at the point of maximum wear (point P4) can be increased, thus further extending the service life of the crushing roller 13.

[0110] Furthermore, when the roller portion 49 is installed on the journal housing 48, the roller portion 49 is sometimes heated and heat-fitted onto the journal housing 48. At this time, thermal stress is generated inside the roller portion 49. However, in this embodiment, as described above, the ceramic portion 52 easily absorbs the thermal stress between the base portion 51 and the ceramic portion 52, thus suppressing damage to the ceramic portion 52 caused by the difference in the coefficient of linear expansion.

[0111] Furthermore, when removing the roller portion 49 from the journal housing 48, it is sometimes easier to remove it by heating the roller portion 49. At this time, thermal stress is also generated inside the roller portion 49. However, in this embodiment, as described above, the ceramic portion 52 easily absorbs the thermal stress between the base portion 51 and the ceramic portion 52, thus suppressing damage to the ceramic portion 52 caused by the difference in the coefficient of linear expansion.

[0112] Thus, in this embodiment, the installation and replacement of the roller section 49 can be easily carried out.

[0113] Furthermore, this disclosure is not limited to the above-described embodiments, and appropriate modifications can be made without departing from its spirit.

[0114] For example, the solid fuels used are not limited to those disclosed herein, and can include coal, biomass fuels, petroleum coke (PC), etc. Furthermore, these solid fuels can be used in combination.

[0115] Furthermore, the shape of the boundary surface is not limited to the shape described in the above embodiments; for example, it may also be the shape shown below.

[0116] [Variation Example 1]

[0117] use Figure 6 Let's illustrate with variation example 1.

[0118] In this embodiment, the curved portion 53Aa of the boundary surface 53A is sandwiched between two straight portions (straight portion 53Ab and straight portion 53Ac). The curved portion 53Aa is smoothly connected to the straight portion 53Ab. In addition, the curved portion 53Aa is also smoothly connected to the straight portion 53Ac. Similar to the curved portion 53a in the first embodiment, the curved portion 53Aa is located on the end face side (base end side) closer to the maximum wear point P1, and is curved in a way that it protrudes toward the outer peripheral surface 49a of the roller portion 49.

[0119] Even in this manner, the same effect as the above-described embodiment is achieved. Furthermore, in this embodiment, the length of the bent portion 53Aa can be shorter than in the above embodiment, making it easier to manufacture the roller portion 49. Additionally, in this embodiment, it is easier to increase the length of the ceramic portion 52 exposed on the base end face of the roller portion 49. Therefore, when the ceramic block CB is subjected to buoyancy during roller casting, the surface area in contact with the mold 60 and supporting the buoyancy is larger, thereby reducing the risk of the ceramic block CB tipping over within the mold 60 during roller casting and further improving the yield.

[0120] [Variation Example 2]

[0121] Next, use Figure 7 Let's illustrate with variation example 2.

[0122] In this embodiment, the boundary surface 53B is provided with a first curved portion 53Ba, a first straight portion 53Bb, a second curved portion 53Bc, and a second straight portion 53Bd sequentially from the starting point 53s. Adjacent portions are smoothly connected to each other. The first curved portion 53Ba and the second curved portion 53Bc are similar to the curved portion 53a in the first embodiment, located on the end face side closer to the maximum wear point P1, and are curved in a way that they protrude toward the outer peripheral surface 49a of the roller portion 49.

[0123] Even in this manner, the same effect as the above-described embodiment is achieved. Furthermore, in this embodiment, compared to the above embodiment, the length of the bent portion 53Aa can be further shortened, thus making it easier to manufacture the roll portion 49. In addition, in this embodiment, the bent portions are distributed at both the first bent portion 53Ba and the second bent portion 53Bc, thus dispersing the stress concentration generated at each bent portion and more effectively suppressing damage to the ceramic portion 52 caused by the difference in the coefficient of linear expansion during casting. Moreover, by providing the bent portion near the base end, the thickness of the ceramic block CB near the base end can be suppressed, and when the ceramic block CB is subjected to buoyancy during roll casting, the surface area in contact with the mold 60 and supporting the buoyancy can be increased. Therefore, the risk of the ceramic block CB tipping over within the mold 60 during roll casting can be reduced, further improving the yield and reducing costs.

[0124] [Variation Example 3]

[0125] Next, use Figure 8 The following describes a variation of this embodiment, Example 3.

[0126] In this embodiment, the boundary surface 53C is provided with a straight portion 53Ca, a curved portion 53Cb, and a recessed portion 53Cc sequentially from the starting point 53s. Adjacent portions are smoothly connected to each other. The curved portion 53Cb, like the curved portion 53a in the first embodiment, is located on the end face side closer to the maximum wear point P1, and is curved in a way that it protrudes toward the outer peripheral surface 49a of the roller portion 49. The recessed portion 53Cc is curved away from the outer peripheral surface 49a of the roller portion 49.

[0127] Even in this manner, it achieves the same effect as the above-described embodiments. In addition, since the recess 53Cc is provided, the ceramic layer at the points of greatest wear (points P1 and P4) can be made thicker, thereby extending the life of the crushing roller 13.

[0128] The crushing roller, solid fuel crushing apparatus, and manufacturing method of the crushing roller described in the above embodiments are as follows.

[0129] According to one aspect of this disclosure, a crushing roller is housed inside a housing (11). Solid fuel is sandwiched between the crushing roller and a rotating crushing table (12) to crush the solid fuel. The crushing roller is rotated by the rotational force from the crushing table (12). The crushing roller (13) includes: a support portion (48) supported to rotate relative to the housing (11); and an annular roller portion (49) fixed to the support portion (48) and crushing solid fuel between the roller portion (49) and the crushing table (12). The roller portion (49) has: a base portion (51) fixed to the support portion (48); and an outer peripheral portion (52) disposed on the outer peripheral surface of the base portion (51). The coefficient of linear expansion is different from that of the base (51) and the wear resistance of the outer peripheral portion (52) is better than that of the base (51). When the roller portion (49) is cut in the direction of the extension of the plane including the rotation center axis (C2) of the roller portion (49), the boundary surface (53) between the base (51) and the outer peripheral portion (52) has a bend (53a) that bends toward the outer peripheral surface (49a) of the roller portion (49) at the end face (13b) near the maximum wear point (P1) of the roller portion (49), which is the point on the outer peripheral surface (49a) of the roller portion (49) that is most easily worn.

[0130] In the above structure, the boundary surface between the base and the outer periphery in the cross-section (hereinafter referred to as the "axial direction section") cut along the extension direction of the rotation center axis of the roller has a bend at the end face side relative to the point of maximum wear. This bend protrudes towards the outer periphery of the roller. As a result, the thickness of the outer periphery decreases at the bend. Therefore, the rigidity of the outer periphery can be reduced. Consequently, the outer periphery readily absorbs thermal stress between the base and the outer periphery, thus suppressing damage to the outer periphery caused by the difference in linear expansion coefficients. This improves the yield rate when manufacturing the crushing roller, thereby reducing manufacturing costs.

[0131] On the other hand, the thickness of the outer periphery does not decrease at the point of maximum wear, thus maintaining the wear resistance of the crushing roller. Therefore, it is possible to suppress the shortening of the crushing roller's lifespan and extend its service life.

[0132] Thus, the above structure can improve the yield rate when manufacturing crushing rollers and extend the service life of crushing rollers.

[0133] Furthermore, examples of materials for the base include metals (more specifically, high-chromium cast iron). Examples of materials for the outer periphery include ceramics.

[0134] In addition, in one aspect of the crushing roller disclosed herein, the outer peripheral surface (49a) of the roller portion (49) is arc-shaped in the cross section, and the maximum wear point (P1) is located in the outer peripheral surface (49a) at an angle of 3 to 13 degrees relative to the center line (C3). The center line (C3) is a line that is orthogonal to the rotation center axis (C2) and passes through the center portion of the rotation center axis (C2) in the extension direction.

[0135] In the above structure, the thickness of the outer periphery does not decrease at the point of maximum wear, thus maintaining the wear resistance of the crushing roller. Therefore, it is possible to suppress the shortening of the crushing roller's lifespan and extend its service life.

[0136] In addition, in one aspect of the crushing roller disclosed herein, the aforementioned boundary surface (53) has a straight portion (53b) extending in a straight line, which is smoothly connected to the aforementioned curved portion (53a).

[0137] In the above structure, the boundary surface has a straight portion. Therefore, compared to a structure where the entire boundary surface is curved, the roller portion can be manufactured more easily. For example, when manufacturing the outer periphery by casting, it is necessary to cut the portion corresponding to the curved portion in the mold used for manufacturing the outer periphery into a curved surface. However, compared to cutting it into a flat surface, cutting into a curved surface is more difficult. Therefore, in the above structure, compared to a structure where the entire boundary surface is curved, the portion cut into curved surfaces can be reduced, thus making it easier to manufacture the outer periphery. Furthermore, it is easier to manufacture the roller portion.

[0138] Furthermore, in the above structure, the straight portion and the curved portion are smoothly connected. This reduces the likelihood of stress concentration when thermal stress is applied to the base and outer periphery. Therefore, damage to the outer periphery caused by the difference in linear expansion coefficients can be suppressed.

[0139] In addition, a smooth connection refers to a connection in a way that does not have steps or other defects in the connection between the straight and curved parts.

[0140] In addition, in one aspect of the crushing roller disclosed herein, the aforementioned boundary surface (53) has a recess (53Cc) that is recessed at the aforementioned maximum wear point (P1) in a manner away from the aforementioned outer peripheral surface (49a) of the roller portion (49), and the aforementioned recess is smoothly connected to the aforementioned curved portion (53a).

[0141] In the above structure, the recess and the curved portion are smoothly connected. Therefore, when thermal stress acts on the base and the outer periphery, stress concentration is less likely to occur. Thus, damage to the outer periphery caused by the difference in linear expansion coefficients can be suppressed.

[0142] Furthermore, a smooth connection refers to a connection where there are no steps or other irregularities at the connection point between the recess and the bend. Additionally, a thicker ceramic layer can be made at the point of greatest wear, thus extending the lifespan of the crushing roller.

[0143] In addition, in one aspect of the crushing roller disclosed herein, the outer peripheral surface (49a) of the roller portion (49) is arc-shaped in the cross section, and the radius of curvature of the curved portion (53a) is 10% or more of the radius of curvature of the outer peripheral surface.

[0144] If the radius of curvature of the bend is too small, stress concentration will occur in the bend, which may become the starting point of damage caused by thermal stress.

[0145] On the other hand, in the above structure, the radius of curvature of the bent portion is more than 10% of the radius of curvature of the outer peripheral surface. This prevents the radius of curvature of the bent portion from becoming too small, thus reducing stress concentration. Therefore, damage to the outer peripheral portion caused by the difference in linear expansion coefficients can be suppressed.

[0146] In addition, one aspect of the solid fuel pulverizing apparatus disclosed herein includes: a pulverizing roller (13) as described in any of the above; a pulverizing table (12) that rotates to clamp solid fuel between the pulverizing table (12) and the pulverizing roller (13) to pulverize solid fuel; and a housing (11) that houses the pulverizing roller (13) and the pulverizing table (12).

[0147] In addition, in one aspect of the manufacturing method of the crushing roller disclosed herein, the crushing roller is housed inside a housing (11), and solid fuel is sandwiched between the crushing roller and a rotating crushing table (12) to crush the solid fuel. The crushing roller is rotated by the rotational force from the crushing table (12). The crushing roller (13) includes: a support portion (48) fixed to the housing (11); and an annular roller portion (49) rotatably supported on the support portion (48) about the support portion (48). The roller portion (49) crushes solid fuel between the crushing table (12). The roller portion (49) includes: a base portion (51) supported on the support portion (48); and an outer peripheral portion (52) disposed on the outer peripheral surface of the base portion (51). The coefficient of linear expansion of (52) is different from that of the base (51), and the wear resistance of the outer peripheral portion (52) is better than that of the base (51). When the roller portion (49) is cut in the cross section with the extension direction including the rotation center axis of the roller portion (49), the boundary surface (53) between the base (51) and the outer peripheral portion (52) has a bend (53a) that bends toward the outer peripheral surface of the roller portion (49) at the end face side near the maximum wear point (P1) of the roller portion (49). The maximum wear point is the point where the roller portion (49) is most easily worn. The manufacturing method of the crushing roller includes a process of integrally forming the base (51) and the outer peripheral portion (52) by casting.

[0148] Explanation of reference numerals in the attached figures

[0149] 1: Power generation equipment

[0150] 10: Grinding mill

[0151] 11: Shell

[0152] 12: Crushing Table

[0153] 13: Crushing Roller

[0154] 13b: End face

[0155] 14: Reducer

[0156] 15: Mill motor

[0157] 16: Rotary grading machine

[0158] 16a: Blade

[0159] 17: Coal supply pipe

[0160] 18: Grading machine motor

[0161] 19: Export Port

[0162] 21: Hopper

[0163] 22: Material drop section

[0164] 25: Coal feeder

[0165] 26: Conveying Department

[0166] 27: Coal feeder motor

[0167] 30: Air Supply Department

[0168] 30a: Hot airflow path

[0169] 30b: Cold airflow path

[0170] 30c: Hot air damper

[0171] 30d: Air conditioning damper

[0172] 31: Primary air ventilation fan

[0173] 34: Air preheater

[0174] 40: Condition Detection Department

[0175] 41: Bottom surface

[0176] 42: Top

[0177] 43: Journal head

[0178] 44: Support arm

[0179] 45: Support shaft

[0180] 46: Pressing device

[0181] 47: Journal Shaft

[0182] 48: Journal housing (support part)

[0183] 49: Roller section

[0184] 49a: outer peripheral surface

[0185] 50: Control Department

[0186] 51: Base

[0187] 51a: outer peripheral surface

[0188] 52: Ceramic section (outer perimeter)

[0189] 52a: outer peripheral surface

[0190] 53: Boundary surface

[0191] 53A: Boundary surface

[0192] 53Aa: Bend

[0193] 53Ab : Straight part

[0194] 53Ac: Straight section

[0195] 53B: Boundary surface

[0196] 53Ba: First bend

[0197] 53Bb: First straight section

[0198] 53Bc: Second bend

[0199] 53Bd: Second straight section

[0200] 53C: Boundary surface

[0201] 53Cb: Bend portion

[0202] 53Cc: concave part

[0203] 53a: Bend

[0204] 53ae: End point

[0205] 53as: Starting point

[0206] 53b: Straight section

[0207] 53c: Bending section

[0208] 53e: End Point

[0209] 53s: Starting point

[0210] 60: Casting mold

[0211] 61: Gate

[0212] 62: Sprue

[0213] 100: Solid fuel pulverizing device

[0214] 110: Primary airflow path

[0215] 120: Micro fuel supply pipe

[0216] 200: Boiler

[0217] 210: Furnace

[0218] 220: Burner.

Claims

1. A pulverizing roller, housed inside a housing, for pulverizing solid fuel by clamping it between the pulverizing roller and a rotating pulverizing table, the pulverizing roller rotating in response to a rotational force from the pulverizing table. The crushing roller comprises: The support portion is supported so that it can rotate relative to the housing; and A circular roller, fixed to the support, pulverizes solid fuel between the roller and the pulverizing table. The roller portion has: a base portion fixed to the support portion; and an outer peripheral portion disposed on the outer peripheral surface of the base portion, wherein the coefficient of linear expansion of the outer peripheral portion is different from that of the base portion and the wear resistance of the outer peripheral portion is superior to that of the base portion. In the cross-section of the roller portion cut by a surface including the extension direction of the rotation center axis of the roller portion, the boundary surface between the base portion and the outer peripheral portion has a curved portion at the end face side near the maximum wear point, which is the point on the outer peripheral surface of the roller portion that is most easily worn. The curved portion is curved in a way that reduces the thickness of the outer peripheral portion at the end face side near the maximum wear point.

2. The crushing roller according to claim 1, wherein, The outer peripheral surface of the roller is arc-shaped in the cross-section. The point of maximum wear is located on the outer peripheral surface at an angle of 3 to 13 degrees relative to the centerline, which is a line orthogonal to the axis of rotation and passing through the center of the extension direction of the axis of rotation.

3. The crushing roller according to claim 1 or 2, wherein, The boundary surface has a straight portion that extends in a straight line. The straight portion and the curved portion are smoothly connected.

4. The crushing roller according to claim 1 or 2, wherein, The boundary surface has a recess at the point of maximum wear that is recessed away from the outer peripheral surface of the roller. The recessed portion is smoothly connected to the curved portion.

5. The crushing roller according to claim 1 or 2, wherein, The outer peripheral surface of the roller is arc-shaped in the cross-section. The radius of curvature of the curved portion is more than 10% of the radius of curvature of the outer peripheral surface.

6. A solid fuel pulverizing device, comprising: The crushing roller according to any one of claims 1 to 5; A pulverizing table rotates, and solid fuel is clamped between the pulverizing table and the pulverizing roller to pulverize the solid fuel; and The housing contains the crushing roller and the crushing table.

7. A method for manufacturing a crushing roller, wherein the crushing roller is housed inside a housing, solid fuel is sandwiched between the crushing roller and a rotating crushing table to crush the solid fuel, and the crushing roller is rotated by a rotational force from the crushing table. The crushing roller comprises: Support portion, fixed to the housing; and The annular roller, supported by the support, is capable of rotating around the support and pulverizing solid fuel between the roller and the pulverizing table. The roller portion includes: a base portion supported by the support portion; and an outer peripheral portion disposed on the outer peripheral surface of the base portion. The coefficient of linear expansion of the outer peripheral portion is different from that of the base portion, and the wear resistance of the outer peripheral portion is superior to that of the base portion. In a cross-section of the roller portion cut along a surface extending from the rotational axis of the roller portion, the boundary surface between the base portion and the outer peripheral portion has a curved portion near the end face of the maximum wear point, protruding towards the outer peripheral surface of the roller portion. The maximum wear point is the point on the outer peripheral surface of the roller portion most easily worn. The curved portion is curved to reduce the thickness of the outer peripheral portion near the end face of the maximum wear point. The manufacturing method of the crushing roller includes a step of integrally forming the base and the outer peripheral portion by casting.

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