crusher

Abstract

To prevent a crushed raw material from accumulating in an internal part.SOLUTION: Provided is a crusher 100 which comprises a crushing table, a crushing roller unit, and an air outlet for blowing out carrier gas upward. The crushing roller unit includes: a journal head to be attached to a housing; a journal shaft supported by the journal head; a crushing roller to be fitted to the journal shaft so as to be rotatable around an axis; a support shaft 34 for making the journal head rotate; and an accumulation preventive member 35 for preventing solid fuel crushed by the crushing roller from accumulating in the crushing roller unit. The accumulation preventive member 35 is fitted to an upper side in a vertical direction of the crushing roller unit, and forms a filling space PS using a plurality of surfaces including inclined surfaces 35a1, 35a2 for making a raw material crushed by the crushing roller fall to a lower side in the vertical direction. The filling space PS is filled with a filling member 35c.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a grinding machine. [Background technology]

[0002] Pulverizers such as vertical mills are configured to pulverize supplied solid fuels such as biomass and coal by pressing rotatably supported pulverizing rollers against a pulverizing table that rotates by power (see, for example, Patent Document 1). Due to its structure, there are areas inside the pulverizer where pulverized solid fuels tend to accumulate, and if solid fuel accumulates in those areas, it will be exposed to high-temperature hot air (carrier gas) for a long period of time, and the accumulated solid fuel may ignite due to spontaneous oxidation and temperature rise.

[0003] Patent Document 1 discloses that a sloping structure is provided on the journal head of a pulverizer to prevent accumulation of pulverized solid fuel. Patent Document 1 discloses that a sloping structure having a sloping surface formed to be larger than the angle of repose of fine powder of solid fuel is cast together with the journal head to be integrally formed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-86304 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the inclined structure is formed integrally at the casting stage of the journal head, the manufacturing cost of the journal head increases due to the increase in size, and the increase in the weight of the parts may reduce the maintainability during installation and replacement. In addition, it is possible to reduce the weight by making the internal space of the inclined structure hollow, but if a part of the inclined structure is damaged and solid fuel enters the internal space of the inclined structure, the solid fuel will accumulate in the internal space of the inclined structure, and the accumulated solid fuel may ignite due to natural oxidation and heating.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a grinding machine that is capable of preventing the malfunction of ground raw materials accumulating inside and catching fire. [Means for solving the problem]

[0007] In order to solve the above problems, the pulverizer of the present disclosure employs the following measures. A crusher according to one aspect of the present disclosure includes a crushing table that rotates about an axis, and a crushing roller unit that crushes raw material supplied from a raw material supply unit to the crushing table between the crushing table and the crushing roller unit, the crushing roller unit having a journal head attached to a housing, a journal shaft supported by the journal head and extending along an axis, a crushing roller attached to the journal shaft so as to be rotatable about the axis, a support shaft that rotates the journal head, and a deposit prevention member that prevents the raw material crushed by the crushing roller from depositing in the crushing roller unit, the deposit prevention member being attached to the vertical upper side of the crushing roller unit and having a plurality of surfaces including an inclined surface that causes the raw material crushed by the crushing roller to fall vertically downward, and the filling space is filled with a filling member. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a crusher capable of preventing the malfunction of crushed raw materials accumulating inside and catching fire, without increasing manufacturing costs. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a crusher according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a perspective view of the crushing roller unit shown in FIG. [Diagram 3] 3 is a cross-sectional view showing a deposition prevention member attached to a support shaft of the crushing roller unit shown in FIG. 2. [Figure 4] 4 is a cross-sectional view showing a first modified example of the deposition prevention member shown in FIG. [Diagram 5] 4 is a cross-sectional view showing a second modified example of the deposition prevention member shown in FIG. [Figure 6] 2 is a partially enlarged view showing a load application device to which the deposition prevention member shown in FIG. 1 is attached. FIG. [Figure 7] 7 is a cross-sectional view taken along the line AA of the load application device to which the deposition prevention member shown in FIG. 6 is attached. [Figure 8] 7 is a cross-sectional view taken along the line BB of the load application device to which the deposition prevention member shown in FIG. 6 is attached. [Figure 9] FIG. 2 is a perspective view of the grinding table shown in FIG. 1. [Figure 10] 10 is a cross-sectional view of the scraper and its vicinity shown in FIG. 9. [Figure 11] FIG. 11 is a cross-sectional view showing a comparative example of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a pulverizer 100 according to an embodiment of the present disclosure will be described with reference to the drawings. The pulverizer 100 of this embodiment is a device that supplies pulverized fuel to a boiler (not shown) of a power plant (not shown). Fig. 1 is a vertical cross-sectional view showing the pulverizer according to this embodiment.

[0011] The crusher 100 includes a housing 10, a crushing table 20, a crushing roller unit 30, a reducer 40, a mill motor 41 connected to the reducer 40 and driving the crushing table 20 to rotate, a rotary classifier 50, a classifier motor 51 that drives the rotary classifier 50 to rotate, a coal supply pipe (raw material supply section) 60, and an outlet 70.

[0012] The housing 10 is a cylindrical case having a central axis Ch extending in the vertical direction, and is a case that houses the crushing table 20, the crushing roller unit 30, the rotary classifier 50, and the coal feed pipe 60. An opening 11 is formed in the peripheral wall of the housing 10, and the crushing roller unit 30 is installed near the opening 11. When the crushing roller unit 30 is installed, the opening 11 is covered by a roller cover 12 that forms the outer wall of the crusher 100 together with the housing 10.

[0013] A coal feed pipe 60 is attached to the center of the ceiling 13 of the housing 10. The coal feed pipe 60 supplies solid fuel introduced through a coal feeder (not shown) into the housing 10. The coal feed pipe 60 is disposed in the vertical direction at the center of the housing 10 and has a lower end extending into the interior of the housing 10.

[0014] A reducer 40 is installed near the bottom portion 14 of the housing 10, and the grinding table 20 is freely rotatably arranged to rotate about an axis Ch by a driving force transmitted from a mill motor 41 connected to the reducer 40.

[0015] The crushing table 20 is a circular member in a plan view, and is arranged so that the lower end of the coal supply pipe 60 faces it. The coal supply pipe 60 supplies solid fuel (for example, coal or biomass fuel in this embodiment) from above toward the crushing table 20 below. The crushing table 20 pinches the supplied solid fuel between the crushing roller 33 and the crushing table 20 to crush it.

[0016] When solid fuel is fed from the coal feed pipe 60 toward the center of the crushing table 20, the centrifugal force generated by the rotation of the crushing table 20 guides the solid fuel to the outer periphery of the crushing table 20, where it is pinched and crushed between the crushing table 20 and the crushing rollers 33. The crushed solid fuel is guided from a carrier gas flow path (not shown) and blown upward by the carrier gas (hereinafter referred to as "primary air") blown out from the outlet 70, and is guided to the rotary classifier 50.

[0017] The air outlet 70 is provided on the outer periphery of the grinding table 20 and is a device that blows out primary air upward. The air outlet 70 is disposed between the outer periphery of the grinding table 20 and the inner periphery of the housing 10, and causes the primary air that flows into the lower part of the housing 10 to flow out into the space above the grinding table 20 within the housing 10. A swirl blade 71 is provided on the outer periphery of the grinding table 20 located at the outlet of the air outlet 70, and applies a swirling force to the primary air blown out upward from the air outlet 70.

[0018] The primary air given a swirling force by the swirling vanes 71 becomes an airflow having a swirling velocity component, and conveys the solid fuel (raw material) pulverized on the grinding table 20 to the rotary classifier 50 located at the upper part within the housing 10. Among the pulverized solid fuel, particles larger than a predetermined particle size are classified by the rotary classifier 50, or fall without reaching the rotary classifier 50 and are returned to the grinding table 20 and pulverized again between the grinding table 20 and the grinding roller 33.

[0019] The crushing roller unit 30 is a device that crushes solid fuel supplied to the crushing table 20 from the coal supply pipe 60 between the crushing roller unit 30 and the crushing table 20. The crushing roller unit 30 includes a journal head 31, a journal shaft 32, a crushing roller 33, a support shaft 34, accumulation prevention members 35, 36, and 37, and a load application device 38.

[0020] The crushing roller 33 is a rotating body that crushes the solid fuel supplied onto the crushing table 20 from the coal supply pipe 60. The crushing roller 33 is pressed against the upper surface of the crushing table 20 to crush the solid fuel in cooperation with the crushing table 20. Although only one crushing roller 33 is shown in FIG. 1 as a representative, a plurality of crushing rollers 33 are arranged at regular intervals in the circumferential direction so as to press against the upper surface of the crushing table 20.

[0021] For example, three crushing rollers 33 are arranged on the outer periphery at equal intervals in the circumferential direction, with an angular interval of 120° between them. In this case, the portions where the three crushing rollers 33 contact the upper surface of the crushing table 20 (the portions that press against each other) are equidistant from the central axis of rotation of the crushing table 20. In addition, three openings 11 are formed in the housing 10 at equal intervals in the circumferential direction.

[0022] The crushing roller 33 is supported by a journal head 31 attached to the housing 10 and is attached to a journal shaft 32 extending along the axis Cj. The crushing roller 33 is rotatable about the axis Cj. The crushing roller 33 supported by the journal head 31 is capable of swinging and displacing up and down as the journal head 31 rotates about a support shaft 34 extending horizontally. The support shaft 34 can move the crushing roller 33 closer to or farther from the upper surface of the crushing table 20 by rotating the journal head 31.

[0023] When the grinding table 20 rotates, the grinding roller 33 receives a rotational force from the grinding table 20 and rotates with the grinding table 20 while the outer circumferential surface of the grinding roller 33 is in contact with the solid fuel on the upper surface of the grinding table 20. When solid fuel is supplied from the coal supply pipe 60, the solid fuel is pressed between the grinding roller 33 and the grinding table 20 and is crushed. This pressing force is called the grinding load.

[0024] An intermediate piston 38a of a load applying device 38 is in contact with the upper end of the journal head 31. The load applying device 38 is a device that applies a load (crushing load) to the journal head 31 so as to press the crushing roller 33 against the crushing table 20, and is fixed to the roller cover 12.

[0025] The load applying device 38 is a device that applies a crushing load along the axis Cf to the upper end of the journal head 31. The load applying device 38 has an intermediate piston 38a and a piston housing 38b, and is configured so that the operating force generated in the hydraulic cylinder 38c is transmitted from the piston 38c1 of the hydraulic cylinder 38c to the upper end of the journal head 31 via the intermediate piston 38a. The intermediate piston 38a is accommodated in the piston housing 38b and is slidable along the direction of the axis Cf.

[0026] The reducer 40 is connected to a mill motor 41 and transmits the driving force of the mill motor 41 to the grinding table 20, causing the grinding table 20 to rotate about its central axis.

[0027] The rotary classifier 50 is provided on the upper part of the housing 10 and has a hollow inverted cone-shaped outer shape. The rotary classifier 50 has a plurality of blades extending in the vertical direction at the outer periphery thereof. The blades are provided at predetermined intervals (equally spaced) around the central axis of the rotary classifier 50. The rotary classifier 50 classifies the solid fuel pulverized by the pulverizing table 20 and the pulverizing roller 33 (hereinafter, the pulverized solid fuel is referred to as "pulverized fuel") into particles having a particle size larger than a predetermined particle size (for example, 70 to 100 μm for coal) (hereinafter, the pulverized fuel having a particle size larger than the predetermined particle size is referred to as "coarse pulverized fuel") and particles having a particle size equal to or smaller than the predetermined particle size (hereinafter, the pulverized fuel having a particle size equal to or smaller than the predetermined particle size is referred to as "fine pulverized fuel").

[0028] The rotary classifier 50 is given a rotational driving force by a classifier motor 51 and rotates around a coal feed pipe 60 centered on a cylindrical axis (not shown) extending in the vertical direction of the housing 10. In this embodiment, the rotary classifier 50 is used, but a fixed classifier including a fixed hollow inverted cone-shaped casing and a plurality of fixed swirl vanes at the outer periphery of the casing may also be used.

[0029] When the pulverized fuel reaches the rotary classifier 50, due to the relative balance between the centrifugal force generated by the rotation of the blades and the centripetal force of the primary air flow, large diameter coarse pulverized fuel particles are knocked down by the blades and returned to the pulverizing table 20 for re-pulverization, while the fine pulverized fuel is guided to the outlet port 13a in the ceiling 13 of the housing 10. The fine pulverized fuel classified by the rotary classifier 50 is discharged together with the primary air from the outlet port 13a into a fine fuel supply passage (not shown) and supplied to the boiler burner.

[0030] The coal supply pipe 60 is attached so that its lower end extends vertically into the interior of the housing 10 so as to penetrate the ceiling portion 13 of the housing 10, and supplies solid fuel fed from the upper portion of the coal supply pipe 60 to the center portion of the grinding table 20. A coal feeder (not shown) is connected to the upper end of the coal supply pipe 60, and solid fuel is supplied.

[0031] Next, the deposition prevention member 35 will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a perspective view of the crushing roller unit 30 shown in Fig. 1. Fig. 3 is a cross-sectional view showing the deposition prevention member 35 attached to the support shaft 34 of the crushing roller unit 30 shown in Fig. 2.

[0032] The deposition prevention member 35 is a member that prevents the solid fuel pulverized by the crushing roller 33 from depositing above the support shaft 34 of the crushing roller unit 30. As shown in Figs. 2 and 3, the deposition prevention member 35 has a plate-shaped member 35a bent at approximately the center in the horizontal direction HD perpendicular to the vertical direction VD, and a plate-shaped member 35b that closes one end of the deposition prevention member 35 in the direction along the axis Cs along which the support shaft 34 extends. The other end of the deposition prevention member 35 in the direction along the axis Cs is closed by the journal head 31. In addition, the other end of the deposition prevention member 35 in the direction along the axis Cs may be closed by a plate-shaped member (not shown).

[0033] The deposition prevention member 35 is detachably fixed to the support shaft 34 with bolts or the like. The plate-shaped members 35a and 35b are formed of, for example, a metal material.

[0034] The accumulation prevention member 35 is attached to the upper side in the vertical direction VD of the crushing roller unit 30, and is formed in a box shape. The accumulation prevention member 35 forms a filling space PS by a pair of inclined surfaces 35a1, 35a2 that drop the solid fuel downward in the vertical direction VD, a surface formed by the plate-shaped member 35b, an upper surface of the support shaft 34 in the vertical direction VD, and a plurality of surfaces including the surface of the journal head 31. The inclined surfaces 35a1, 35a2 are arranged to have an angle equal to or greater than the angle of repose of the solid fuel crushed by the crushing roller 33.

[0035] The inclined surfaces 35a1 and 35a2 of the plate-shaped member 35a and the surface of the plate-shaped member 35b are made of stainless steel, hardfacing steel plate, ceramic-lined steel plate, or carbon steel plate. The filling space PS formed by the deposition prevention member 35 is filled with a filling member 35c. The filling member 35c is, for example, a cement-based material.

[0036] When the deposition prevention member 35 is prepared in advance at a factory, the deposition prevention member 35 filled with the filling material 35c at the factory and sealed is simply installed on-site, which reduces the installation man-hours and costs. When the deposition prevention member 35 is prepared on-site, the inclined surfaces 35a1 and 35a2 and the plate-shaped member 35b are installed on the upper surface of the installation member (journal head 31), the filling material 35c is filled through the filling port (not shown) provided on the inclined surfaces 35a1 and 35a2, and the filling port is then closed to complete the installation process. In this case, the bottom of the deposition prevention member 35 can be substituted by the surface of the journal head 31, so that the number of metal parts can be reduced and the manufacturing cost can be reduced. Furthermore, the weight can be reduced by reducing the number of parts, which improves maintainability.

[0037] Here, with reference to Fig. 4, a first modified example of the deposition prevention member 35 shown in Fig. 3 will be described. Fig. 4 is a cross-sectional view showing the first modified example of the deposition prevention member 35 shown in Fig. 3. The deposition prevention member 35 shown in Fig. 3 forms a filling space PS by the upper surface of the support shaft 34 in the vertical direction VD.

[0038] In contrast, a first modified example of the deposition prevention member 35 shown in Fig. 4 forms the filling space PS by a plate-shaped member 35d arranged along the upper surface in the vertical direction VD of the support shaft 34. The first modified example of the deposition prevention member 35 shown in Fig. 4 is a substantially triangular prism-shaped member having five surfaces formed by plate-shaped members 35a, 35b, and 35d.

[0039] Next, a second modified example of the deposition prevention member 35 shown in FIG. 3 will be described with reference to FIG. 5. FIG. 5 is a cross-sectional view showing a second modified example of the deposition prevention member 35 shown in FIG. 3. In the deposition prevention member 35 shown in FIG. 3, the filling member 35c filled in the filling space PS is made of a cement-based material. In contrast, in the second modified example of the deposition prevention member 35 shown in FIG. 5, the filling member 35e filled in the filling space PS is made of a mixture of a granular wear-resistant material such as ceramic beads and a resin material.

[0040] The deposition prevention member 35A is attached to the upper surface in the vertical direction VD of the end of the journal shaft 32 and is formed into a box shape. The structure of the deposition prevention member 35A is similar to that of the deposition prevention member 35, so the following description will be omitted.

[0041] Next, the deposition prevention members 36, 37 will be described with reference to Fig. 6 to Fig. 8. Fig. 6 is a partially enlarged view showing a load application device 38 to which the deposition prevention members 36, 37 shown in Fig. 1 are attached. Fig. 7 is a cross-sectional view taken along line AA of the load application device 38 to which the deposition prevention member 36 shown in Fig. 6 is attached. Fig. 8 is a cross-sectional view taken along line BB of the load application device 38 to which the deposition prevention member 37 shown in Fig. 6 is attached.

[0042] 6 and 7, the deposition prevention member 36 is a member that prevents the solid fuel pulverized by the pulverizing roller 33 from depositing above the piston housing 38b. As shown in Fig. 7, the deposition prevention member 36 has a plate-shaped member 36a bent at approximately the center in the horizontal direction HD perpendicular to the vertical direction VD, and a plate-shaped member 36b that closes one end of the deposition prevention member 36 in the direction along the axis Cf along which the intermediate piston 38a extends. The other end of the deposition prevention member 36 in the direction along the axis Cf is closed by the piston housing 38b.

[0043] The deposition prevention member 36 is detachably fixed to the piston housing 38b with bolts, etc. The plate-shaped members 36a and 36b are formed of, for example, a metal material.

[0044] The deposition prevention member 36 is attached to the upper side of the piston housing 38b and is formed in a box shape. The deposition prevention member 36 forms a filling space PS with a pair of inclined surfaces 36a1, 36a2 that drop the solid fuel downward in the vertical direction VD, a surface formed by the plate-shaped member 36b, an upper surface of the piston housing 38b in the vertical direction VD, and a plurality of surfaces including the surface of the piston housing 38b. The inclined surfaces 36a1, 36a2 are arranged to have an angle equal to or greater than the angle of repose of the solid fuel pulverized by the pulverizing roller 33.

[0045] The inclined surfaces 36a1 and 36a2 of the plate-shaped member 36a and the surface of the plate-shaped member 36b are formed of stainless steel, hardfacing steel plate, ceramic-lined steel plate, or carbon steel plate. The filling space PS formed by the deposition prevention member 36 is filled with a filling member 36c. The filling member 36c is, for example, a cement-based material. The filling member 36c may also be a member made of a mixture of a granular wear-resistant material such as ceramic beads and a resin material.

[0046] Next, the deposition prevention member 37 will be described with reference to Fig. 6 and Fig. 8. As shown in Fig. 6 and Fig. 8, the deposition prevention member 37 is a member that prevents the solid fuel pulverized by the pulverizing roller 33 from depositing above the intermediate piston 38a and the journal head 31.

[0047] 6 and 8, the deposition prevention member 37 has a plate-like member 37a bent at approximately the center in a horizontal direction HD perpendicular to the vertical direction VD, a plate-like member 37b that closes one end of the deposition prevention member 37 in a direction along the axis Cf along which the intermediate piston 38a extends, and a plate-like member 37d that is disposed with a gap CL from the upper surface of the intermediate piston 38a. The other end of the deposition prevention member 37 in the direction along the axis Cf is closed by the piston housing 38b.

[0048] The deposition prevention member 37 is detachably fixed to the piston housing 38b with bolts, etc. The plate-shaped members 37a, 37b, and 37d are formed of, for example, a metal material.

[0049] The deposition prevention member 37 is attached to the piston housing 38b so as to leave a gap CL between it and the upper side of the intermediate piston 38a, and is formed in a box shape. The deposition prevention member 37 forms a filling space PS with a pair of inclined surfaces 37a1, 37a2 that drop the solid fuel downward in the vertical direction VD, a surface formed by the plate-like members 37b and 37d, and a plurality of surfaces including the surface of the piston housing 38b. The inclined surfaces 37a1, 37a2 are arranged to have an angle equal to or greater than the angle of repose of the solid fuel pulverized by the pulverizing roller 33.

[0050] The inclined surfaces 37a1 and 37a2 of the plate-shaped member 37a and the surfaces of the plate-shaped members 37b and 37d are made of stainless steel, hardfacing steel plate, ceramic-lined steel plate, or carbon steel plate. The filling space PS formed by the deposition prevention member 37 is filled with a filling member 37c. The filling member 37c is, for example, a cement-based material. The filling member 37c may also be a granular member made of a resin material.

[0051] Next, the deposition prevention member 22 will be described with reference to Fig. 9 and Fig. 10. Fig. 9 is a perspective view of the crushing table 20 shown in Fig. 1. Fig. 10 is a cross-sectional view of the vicinity of the scraper (moving member) 21 shown in Fig. 9.

[0052] 9, a scraper 21, which is a rod-shaped member protruding in a radial direction RD perpendicular to the axis Ch, is attached to the outer edge of the lower end of the grinding table 20. The scraper 21 is a member that moves the solid fuel F accumulated at the bottom of the internal space of the housing 10 toward the drop port 15 when rotating around the axis Ch.

[0053] The crusher 100 includes an accumulation prevention member 22 that prevents the solid fuel pulverized by the crushing roller 33 from accumulating below the blowing port 70 of the crushing table 20 in the vertical direction VD. The accumulation prevention member 22 is a plate-like member arranged to seal the gap in the radial direction RD between the outer edge of the lower end of the crushing table 20 and the scraper 21 from above in the vertical direction VD. As shown in Fig. 10, the accumulation prevention member 22 has an upper surface 22a that is arranged along a horizontal plane.

[0054] As shown in Fig. 10, below the gap CL2 in the radial direction RD between the outer edge of the lower end of the grinding table 20 and the scraper 21, a discharge port 23 is provided to discharge the raw material that has entered through the gap CL2. The solid fuel F that has entered the gap CL2 is discharged from the discharge port 23 to the internal space of the housing 10. Fig. 11 is a cross-sectional view showing a comparative example of Fig. 10. In the comparative example shown in Fig. 11, the deposition prevention member 22 is not attached to the scraper 21. Therefore, when the solid fuel F with a large particle size flows in from the gap between the scraper 21 and the lower end of the grinding table 20, it blocks the outlet side opening, which is narrower than the inlet side opening, and deposition progresses from the blocked area.

[0055] The actions and effects of the crusher 100 of the present embodiment described above will be described. According to the pulverizer 100 of this embodiment, the accumulation prevention members 35, 36, 37 for preventing the solid fuel pulverized by the pulverizing roller 33 from accumulating on the pulverizing roller unit 30 are attached to the upper side of the pulverizing roller unit 30 in the vertical direction VD. The accumulation prevention members 35, 36, 37 include inclined surfaces 35a1, 35a2, 36a1, 36a2, 37a1, 37a2 for causing the solid fuel pulverized by the pulverizing roller 33 to fall downward in the vertical direction VD. The solid fuel that falls onto the inclined surfaces from above the accumulation prevention members 35, 36, 37 falls downward in the vertical direction VD along the inclined surfaces, and therefore does not accumulate on the pulverizing roller unit 30 at the positions where the accumulation prevention members 35, 36, 37 are installed.

[0056] Moreover, according to the pulverizer 100 of this embodiment, the deposition prevention members 35, 36, 37 form the filling space PS by a plurality of surfaces including an inclined surface. Since the filling space PS is filled with the filling members 35c, 36c, 37c, even if any of the plurality of surfaces is damaged and the solid fuel enters the filling space PS, the excessive solid fuel is prevented from entering and accumulating in the filling space PS. Therefore, it is possible to provide a pulverizer 100 that can prevent the pulverized raw material from accumulating on the crushing roller unit 30 and catching fire without increasing the manufacturing cost.

[0057] According to the crusher 100 of this embodiment, the deposition prevention member 22 that prevents the solid fuel crushed by the crushing roller 33 from depositing below the blowing port 70 of the crushing table 20 in the vertical direction VD is disposed so as to seal the gap CL2 in the radial direction RD between the outer edge of the crushing table 20 and the scraper 21 from above in the vertical direction VD. Since the gap CL2 in the radial direction RD between the outer edge of the crushing table 20 and the scraper 21 is sealed by the deposition prevention member 22, the solid fuel is prevented from depositing in the gap CL2 between the outer edge of the crushing table 20 and the scraper 21.

[0058] Other Embodiments In the above description, a liquid sealant may be applied to the joints or bonding surfaces between the deposit prevention members 35, 36, 37 and the target parts to prevent the pulverized solid fuel from entering. Furthermore, it is preferable that the plate materials constituting the deposition prevention members 35, 36, and 37 are joined together without any gaps by welding, etc. However, if necessary, the members may be bolted or the like so as to be partially removable.

[0059] The filling material should have excellent heat resistance as well as wear resistance, and should be fluid when filled to make it easy to fill, and should self-harden or heat-harden after pouring. If air bubbles are trapped during pouring, they will create cavities that will cause accumulation when the material is worn out and broken, so when pouring, a vibrator or a push rod should be used to push the material into every corner to prevent cavities from forming.

[0060] It is desirable to set the gap CL between the deposition prevention member 37 and the moving target part (intermediate piston 38a) so that it is constant over the entire opposing surface, but it may be allowed to increase or decrease locally within a range in which the solid fuel that has entered the gap CL does not have adverse effects such as natural oxidation temperature rise or restraint of the moving parts.

[0061] Since the deposition prevention member 37 cannot be fixed directly to the moving target part (intermediate piston 38a), if it is attached to a nearby non-moving part, stress may be concentrated at the attachment point like a cantilever beam. Therefore, it is preferable to provide a separate attachment flange or the like at the attachment point and fix the deposition prevention member 37 to the attachment flange or the like.

[0062] The crusher 100 according to the present embodiment described above can be understood, for example, as follows. A crusher (100) according to a first aspect of the present disclosure includes a crushing table (20) that rotates about an axis, and a crushing roller unit (30) that crushes raw material supplied to the crushing table from a raw material supply unit (60) between the table and the crushing table. The crushing roller unit includes a journal head (31) attached to a housing (10), a journal shaft (32) supported by the journal head and extending along an axis, and a crushing roller (33) attached to the journal shaft so as to be rotatable about the axis. The apparatus includes a support shaft (34) for rotating the journal head, and an anti-accumulation member (35, 36, 37) for preventing the raw material crushed by the crushing roller from accumulating in the crushing roller unit, and the anti-accumulation member is attached to the vertical upper side of the crushing roller unit and forms a filling space (PS) with a plurality of surfaces including inclined surfaces (35a1, 35a2) for causing the raw material crushed by the crushing roller to fall vertically downward, and the filling space is filled with a filling member (35c).

[0063] According to the crusher according to the first aspect of the present disclosure, an accumulation prevention member that prevents the raw material crushed by the crushing roller from accumulating on the crushing roller unit is attached to the vertical upper side of the crushing roller unit. The accumulation prevention member includes an inclined surface that causes the raw material crushed by the crushing roller to fall vertically downward. The raw material that falls onto the inclined surface from above the accumulation prevention member falls vertically downward along the inclined surface, and therefore does not accumulate on the crushing roller unit at the position where the accumulation prevention member is installed.

[0064] Moreover, according to the pulverizer according to the first aspect of the present disclosure, the deposition prevention member forms a filling space by a plurality of surfaces including an inclined surface. Since the filling space is filled with the filling member, even if any of the plurality of surfaces is damaged and the raw material enters the filling space, excessive raw material is prevented from entering and accumulating in the filling space. Therefore, it is possible to provide a pulverizer capable of preventing a malfunction in which the pulverized raw material accumulates inside and ignites. Furthermore, the deposition prevention effect reduces the possibility of fire, and the pulverizer can be safely operated even when using inexpensive, low-quality coal such as subbituminous coal or highly flammable solid fuel such as biomass.

[0065] The pulverizer according to the second aspect of the present disclosure is the first aspect, further comprising the following configuration: That is, the filling member is a member in which a granular wear-resistant material and a resin material are mixed. According to the pulverizer according to the second aspect of the present disclosure, the deposition prevention member can be made lighter by using a member made of a mixture of a material having wear resistance of grains and a resin material.

[0066] The pulverizer according to the third aspect of the present disclosure is the second aspect, further comprising the following configuration: the wear-resistant material is a cement-based material. According to the pulverizer according to the third aspect of the present disclosure, the weight can be reduced by using a cement-based material.

[0067] The pulverizer according to a fourth aspect of the present disclosure is any one of the first to third aspects, further comprising the following configuration: the surfaces including the inclined surface are formed of stainless steel, hardfacing steel plate, ceramic lined steel plate, or carbon steel plate. According to the pulverizer according to the fourth aspect of the present disclosure, the multiple surfaces including the inclined surface can be formed from stainless steel, hardfacing steel plate, ceramic lined steel plate, or carbon steel plate.

[0068] The transport and drying gas blown up from the outlets around the grinding table has a wind speed of about 40 m / s. In addition to drying the raw materials inside the grinder, it also guides the ground raw materials to the outlet port via a classifier and transports them to the burner. This transport drying gas contains the raw materials and is blown to various parts at high speed, so the parts near the outlet are prone to wear due to erosion, and it is necessary to select materials that require wear resistance. Therefore, it is desirable for the material of the outer surface of the deposition prevention cover installed near the outlet (where the wind speed exceeds 30 m / s) to be a wear-resistant material. Specifically, SUS stainless steel, hardened steel plate, ceramic-lined steel plate, etc. are preferable.

[0069] The area that does not require abrasion resistance refers to the area away from the air outlet where the wind speed is 30 m / s or less. Since this area does not require abrasion resistance, the material of the outer surface of the accumulation prevention cover can be a normal carbon steel plate. Specifically, it can be a general structural rolled steel such as SS400.

[0070] The crusher according to a fifth aspect of the present disclosure is any one of the first to third aspects, further comprising the following configuration: the inclined surface is disposed so as to have an angle equal to or greater than the angle of repose of the raw material crushed by the crushing roller. According to the crusher of the fifth aspect of the present disclosure, the inclined surface has an angle equal to or greater than the angle of repose of the raw material crushed by the crushing rollers, so that the raw material that falls on the inclined surface can be reliably allowed to fall downward along the inclined surface.

[0071] The crusher according to a sixth aspect of the present disclosure is any one of the first to third aspects, further comprising the following configuration: the filling space is formed by a plurality of the surfaces including the inclined surface and a surface on the vertical upper side of the crushing roller unit. According to the crusher of the sixth aspect of the present disclosure, the filling space is formed by the vertically upper surface of the crushing roller unit, and therefore the vertically upper surface of the crushing roller unit can be utilized as the surface forming the filling space.

[0072] The crusher according to a seventh aspect of the present disclosure is any one of the first to third aspects, further comprising the following configuration: the accumulation prevention member is disposed on the vertical upper side of the crushing roller unit with a gap (CL2) from the surface. According to the pulverizer of the seventh aspect of the present disclosure, the deposition prevention member is disposed on the vertical upper side of the moving member included in the grinding roller unit with a gap from the surface, thereby preventing the deposition prevention member from coming into contact with the moving member and being damaged. The narrower the gap width, the less the amount of raw material that accumulates in the clearance, but if it is too narrow, it may come into contact with the moving target parts and cause abnormal noise, so it is preferable to set it to about 5 to 20 mm. At this level, it can be used safely without reaching the layer thickness required for natural oxidation temperature rise, depending on the atmospheric temperature and the fuel used.

[0073] The crusher according to the eighth aspect of the present disclosure includes a crushing table that rotates around an axis, a crushing roller that crushes the raw material supplied from a raw material supply unit to the crushing table between the crushing table and the crushing roller, an outlet that is provided on the outer periphery of the crushing table and that blows out a conveying gas upward, and a deposition prevention member (22) that prevents the raw material crushed by the crushing roller from accumulating vertically below the outlet of the crushing roller, and a moving member (21) is attached to the outer edge of the crushing table, protruding in a radial direction perpendicular to the axis and moving the raw material that accumulates at the bottom of the internal space of the housing toward a drop port when the crusher rotates around the axis, and the deposition prevention member is a plate-shaped member that is arranged to seal the radial gap between the outer edge and the moving member from above in the vertical direction.

[0074] According to the crusher of the eighth aspect of the present disclosure, the accumulation prevention member that prevents the raw material crushed by the crushing roller from accumulating vertically below the outlet of the crushing table is arranged to seal the radial gap between the outer edge of the crushing table and the moving member from above in the vertical direction. Since the radial gap between the outer edge of the crushing table and the moving member is sealed by the accumulation prevention member, the accumulation of solid fuel in the gap between the outer edge of the crushing table and the moving member is prevented.

[0075] The crusher according to the ninth aspect of the present disclosure is the eighth aspect, further comprising the following configuration: That is, the deposition prevention member has an upper surface (22a) arranged along a horizontal plane. According to the grinding machine of the ninth aspect of the present disclosure, the upper surface of the anti-deposition member is arranged along a horizontal plane, so that when the anti-deposition member rotates in conjunction with the rotation of the grinding table, the raw materials can be appropriately prevented from coming into contact with the anti-deposition member and being thrown in undesired directions. If an angle of repose is provided instead of horizontal, when the mill is cleared, the angle of repose acts as a moving part and excessive raw materials are scraped up, and since the excessively scraped and piled up raw materials have a height, it is possible that they will reach the height of the air supply duct and be pushed in. Therefore, by not providing an angle of repose, the appropriate amount can be scraped up using only the moving part, preventing accumulation and spontaneous combustion. During normal operation, the angle of repose repels the raw materials, preventing them from accumulating in areas that the moving part cannot reach.

[0076] The crusher according to the tenth aspect of the present disclosure is the ninth aspect, and further includes the following configuration: A discharge port (23) is provided below the radial gap between the outer edge portion and the moving member, for discharging the raw material that has entered through the gap. According to the pulverizer of the tenth aspect of the present disclosure, even if the raw material enters the gap, the raw material can be discharged from the discharge port, thereby preventing the raw material from accumulating in the gap. [Explanation of symbols]

[0077] 10. Housing 11 Opening 12 Roller cover 13 Ceiling 13a Exit port 14 Bottom part 15 Drop-off point 20 Grinding Table 21 Scraper (moving part) 22 Accumulation prevention material 22a Top side 23 Outlet 30 Crushing roller unit 31 Journal Head 32 Journal shaft 33 Crushing roller 34 Support shaft 35, 35A, 36, 37 Accumulation prevention member 35a, 35b, 35d, 36a, 36b, 37a, 37b, 37d Plate-shaped members 35a1,35a2,36a1,36a2,37a1,37a2 Slope 35c, 35e, 36c, 37c Filling material 38 Load bearing device 38a Intermediate piston 38b Piston housing 38c Hydraulic Cylinder 38c1 piston 40 Reducer 41 Mill motor 50 Rotary Classifier 51 Classifier motor 60 Coal Feed Pipe 70 Air outlet 71 Swirling blades 100 Crusher CL,CL2 Gap Cf,Ch,Cj,Cs axis line F solid fuel HD horizontal PS filling space RD radial direction VD Vertical direction

Claims

1. A grinding table that rotates around an axis; a crushing roller unit for crushing the raw material supplied to the crushing table from the raw material supply unit between the crushing table and the crushing roller unit, The crushing roller unit includes: a journal head attached to the housing; a journal shaft supported by the journal head and extending along an axis; a crushing roller attached to the journal shaft so as to be rotatable about the axis; A support shaft that rotates the journal head; a deposition prevention member that prevents the raw material crushed by the crushing roller from depositing on the crushing roller unit, the accumulation prevention member is attached to the upper side of the crushing roller unit in the vertical direction, and forms a filling space by a plurality of surfaces including an inclined surface that drops the raw material crushed by the crushing roller to the lower side in the vertical direction; The filling space is filled with a filling material.

2. 2. The pulverizer according to claim 1, wherein the filling member is a mixture of a granular wear-resistant material and a resin material.

3. 3. A pulverizer as claimed in claim 2, wherein the wear-resistant material is a cement-based material.

4. 4. The crusher according to claim 1, wherein the surfaces including the inclined surface are formed from stainless steel, hardfacing steel plate, ceramic lined steel plate, or carbon steel plate.

5. 4. The crusher according to claim 1, wherein the inclined surface is disposed so as to have an angle equal to or larger than an angle of repose of the raw material crushed by the crushing roller.

6. 4. The crusher according to claim 1, wherein the filling space is defined by a plurality of the surfaces including the inclined surface and a surface on an upper side in a vertical direction of the crushing roller unit.

7. The crusher according to claim 1 , wherein the accumulation prevention member is disposed on an upper side in a vertical direction of the crushing roller unit with a gap therebetween.

8. A grinding table that rotates around an axis; A crushing roller that crushes the raw material supplied from the raw material supply unit to the crushing table between the crushing roller and the crushing table; an outlet provided on the outer periphery of the grinding table and configured to blow out a carrier gas upward; and a deposition prevention member that prevents the raw material crushed by the crushing roller from depositing vertically below the blowing port of the crushing table, A moving member is attached to the outer edge of the grinding table, the moving member protruding in a radial direction perpendicular to the axis and moving the raw material accumulated at the bottom of the internal space of the housing that accommodates the grinding table toward a drop port when the moving member rotates around the axis, The deposition prevention member is a plate-shaped member arranged so as to seal the radial gap between the outer edge portion and the moving member from above in the vertical direction.

9. The crusher according to claim 8 , wherein the deposition prevention member has an upper surface disposed along a horizontal plane.

10. The crusher according to claim 9, further comprising a discharge port provided below the radial gap between the outer edge portion and the moving member for discharging the raw material that has entered through the gap.

Images