crusher

Abstract

Provided is a crusher comprising a crushing table, a crushing roller unit, and a discharge port for emitting transport gas upward, the crushing roller unit including a journal head attached to a housing, a journal shaft supported by the journal head, a crushing roller attached to the journal shaft so as to be rotatable about the shaft axis, a support shaft (34) for rotating the journal head, and an accumulation prevention member (35) for preventing solid fuel crushed by the crushing roller from being accumulated on the crushing roller unit, the accumulation prevention member (35) forming a filling space (PS) by a plurality of surfaces including inclined surfaces (35a1, 35a2) that are attached to the upper side of the crushing roller unit in the vertical direction and allow raw materials crushed by the crushing roller to fall downward in the vertical direction, the filling space (PS) being filled with a filling member (35c).

Description

crusher

[0001] The present disclosure relates to a grinder.

[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 using power (see, for example, Patent Document 1).Due to their structure, there are areas within the pulverizer where pulverized solid fuels tend to accumulate.If solid fuel accumulates in these areas, the solid fuel is 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 or other reasons, such as an increase in temperature.

[0003] Patent Document 1 discloses providing a journal head of a pulverizer with an inclined structure to prevent accumulation of pulverized solid fuel. Patent Document 1 discloses that the inclined structure has an inclined surface formed to have an angle of repose larger than the angle of repose of the fine powder of the solid fuel, and is integrally formed by casting the inclined structure together with the journal head.

[0004] Japanese Patent Application Laid-Open No. 2022-86304

[0005] However, if the gradient structure is formed integrally at the journal head casting stage, the increased size increases the manufacturing cost of the journal head, and the increased weight of the parts may reduce maintainability during installation or replacement. While it is also possible to reduce weight by making the internal space of the gradient structure hollow, if damage occurs to a portion of the gradient structure and solid fuel enters the internal space of the gradient structure, the solid fuel may accumulate in the internal space of the gradient structure, and the accumulated solid fuel may ignite due to spontaneous oxidation or other reasons such as an increase in temperature.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a grinder that can prevent the problem of ground raw materials accumulating inside and catching fire.

[0007] In order to solve the above problems, the crusher of the present disclosure employs the following means: 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 to the crushing table from a raw material supply unit 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 accumulating on 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 filler member.

[0008] According to the present disclosure, it is possible to provide a crusher that can prevent the problem of crushed raw materials accumulating inside and catching fire, without increasing manufacturing costs.

[0009] 1. A longitudinal sectional view showing a crusher according to an embodiment of the present disclosure. A perspective view of the crushing roller unit shown in FIG. 1. A sectional view showing a deposition prevention member attached to a support shaft of the crushing roller unit shown in FIG. 2. A sectional view showing a first modified example of the deposition prevention member shown in FIG. 3. A sectional view showing a second modified example of the deposition prevention member shown in FIG. 3. A partially enlarged view showing a load application device to which the deposition prevention member shown in FIG. 1 is attached. A sectional view taken along arrows A-A of the load application device to which the deposition prevention member shown in FIG. 6 is attached. A sectional view taken along arrows B-B of the load application device to which the deposition prevention member shown in FIG. 6 is attached. A perspective view of the crushing table shown in FIG. 1. A sectional view of the vicinity of the scraper shown in FIG. 9. A sectional view showing a comparative example of FIG. 10.

[0010] A pulverizer 100 according to an embodiment of the present disclosure will be described below with reference to the drawings. The pulverizer 100 of this embodiment is an apparatus for supplying pulverized fuel to a boiler (not shown) of a power generation 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 enclosure having a central axis Ch extending in the vertical direction, and 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 which, together with the housing 10, forms the outer wall of the crusher 100.

[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 via a coal feeder (not shown) into the housing 10, and is arranged vertically at the center of the housing 10 with its lower end extending into the interior of the housing 10.

[0014] A reducer 40 is installed near the bottom surface 14 of the housing 10, and a grinding table 20 is arranged to rotate freely around 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 feed pipe 60 faces it. The coal feed 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 sandwiches the supplied solid fuel between itself and the crushing rollers 33 and crushes it.

[0016] When solid fuel is fed from the coal feed pipe 60 toward the center of the grinding table 20, the centrifugal force generated by the rotation of the grinding table 20 guides the solid fuel toward the outer periphery of the grinding table 20, where it is pinched and crushed between the grinding table 20 and the grinding roller 33. The crushed solid fuel is guided through 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 a device that is provided on the outer periphery of the rotary table 20 and that blows out primary air upward. The air outlet 70 is disposed between the outer periphery of the rotary table 20 and the inner periphery of the housing 10, and causes primary air that flows into the lower part of the housing 10 to flow out into the space above the rotary table 20 within the housing 10. A swirl blade 71 is installed on the outer periphery of the rotary table 20 located at the outlet of the air outlet 70, and applies a swirling force to the primary air that is blown out upward from the air outlet 70.

[0018] The primary air given a swirling force by the swirl vanes 71 becomes an airflow with a swirling velocity component, and transports the solid fuel (raw material) pulverized on the grinding table 20 to the rotary classifier 50 located above in the housing 10. Of 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, where they are pulverized again between the grinding table 20 and the grinding rollers 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, deposit prevention members 35, 36, 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 example, 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 at equal intervals in the circumferential direction on the outer periphery at angular intervals of 120°. In this case, the portions of the three crushing rollers 33 that contact (press against) the upper surface of the crushing table 20 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 able to swing and displace up and down as the journal head 31 rotates around a support shaft 34 extending horizontally. By rotating the journal head 31, the support shaft 34 can move the crushing roller 33 closer to or away from the upper surface of the crushing table 20.

[0023] When the grinding table 20 rotates, the grinding roller 33 receives a rotational force from the grinding table 20 and rotates with the outer peripheral surface of the grinding roller 33 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 crushed. This pressing force is called the crushing 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 via the intermediate piston 38a to the upper end of the journal head 31. The intermediate piston 38a is housed 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 rotary table 20, causing the rotary table 20 to rotate around its central axis.

[0027] The rotary classifier 50 is provided at the top of the housing 10 and has a hollow, inverted cone-shaped exterior. The rotary classifier 50 is provided with a plurality of blades extending vertically around its outer periphery. The blades are provided at predetermined intervals (equally spaced) around the central axis of the rotary classifier 50. The rotary classifier 50 classifies solid fuel pulverized by the pulverizing table 20 and the pulverizing roller 33 (hereinafter, the pulverized solid fuel will be referred to as "pulverized fuel") into particles larger than a predetermined particle size (e.g., 70 to 100 μm for coal) (hereinafter, pulverized fuel exceeding the predetermined particle size will be referred to as "coarse pulverized fuel") and particles smaller than the predetermined particle size (hereinafter, pulverized fuel smaller than the predetermined particle size will be referred to as "fine pulverized fuel").

[0028] The rotary classifier 50 is given a rotational driving force by a classifier motor 51 and rotates around the coal feed pipe 60 around 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 having a fixed hollow inverted cone-shaped casing and a plurality of fixed swirl blades positioned on 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 to be pulverized again, and the fine pulverized fuel is led 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 pulverized fuel supply passage (not shown) and supplied to the boiler burner.

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

[0031] Next, the deposition prevention member 35 will be described with reference to Figures 2 and 3. Figure 2 is a perspective view of the crushing roller unit 30 shown in Figure 1. Figure 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 Figure 2.

[0032] The deposition prevention member 35 is a member that prevents the solid fuel pulverized by the crushing roller 33 from accumulating above the support shaft 34 of the crushing roller unit 30. As shown in FIGS. 2 and 3 , the deposition prevention member 35 includes a plate-shaped member 35a bent substantially at the center in a 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 along the axis Cs along which the support shaft 34 extends. The other end of the deposition prevention member 35 along the axis Cs is closed by the journal head 31. Alternatively, the other end of the deposition prevention member 35 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 made of, for example, a metal material.

[0034] The accumulation prevention member 35 is attached to the upper side of the crushing roller unit 30 in the vertical direction VD and is formed in a box shape. The accumulation prevention member 35 forms a filling space PS with a pair of inclined surfaces 35a1 and 35a2 that cause the solid fuel to fall 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 multiple surfaces including the surface of the journal head 31. The inclined surfaces 35a1 and 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 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 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 fabricated in advance at a factory, the deposition prevention member 35 is simply filled with the filler 35c and sealed at the factory, and then installed on-site, thereby reducing installation labor and costs. Furthermore, when fabricating the deposition prevention member 35 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 filler 35c is filled through the filling openings (not shown) provided on the inclined surfaces 35a1 and 35a2, and the filling openings are then closed to complete the installation process. In this case, the surface of the journal head 31 can be used as the bottom of the deposition prevention member 35, thereby reducing the number of metal parts and reducing manufacturing costs. Furthermore, reducing the number of parts also reduces weight, improving maintainability.

[0037] Here, a first modified example of the deposition prevention member 35 shown in Fig. 3 will be described with reference to Fig. 4. 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, in a first modified example of the deposition prevention member 35 shown in Fig. 4, the filling space PS is formed by a plate-like member 35d that is arranged along the upper surface of the support shaft 34 in the vertical direction VD. 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 the plate-like members 35a, 35b, and 35d.

[0039] Next, a second modification 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 the second modification of the deposition prevention member 35 shown in Fig. 3. In the deposition prevention member 35 shown in Fig. 3, the filler member 35c filled in the filling space PS is made of a cement-based material. In contrast, in the second modification of the deposition prevention member 35 shown in Fig. 5, the filler 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 formed in a box shape and is attached to the upper surface in the vertical direction VD of the end of the journal shaft 32. The structure of the deposition prevention member 35A is similar to that of the deposition prevention member 35, and therefore, a description thereof will be omitted below.

[0041] Next, the deposition prevention members 36, 37 will be described with reference to Figures 6 to 8. Figure 6 is a partially enlarged view showing a load application device 38 to which the deposition prevention members 36, 37 shown in Figure 1 are attached. Figure 7 is a cross-sectional view taken along the line A-A of the load application device 38 to which the deposition prevention member 36 shown in Figure 6 is attached. Figure 8 is a cross-sectional view taken along the line B-B of the load application device 38 to which the deposition prevention member 37 shown in Figure 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 accumulating 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 cause the solid fuel to fall 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 multiple 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. Alternatively, the filling member 36c may be 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 Figures 6 and 8. As shown in Figures 6 and 8, the deposition prevention member 37 is a member that prevents the solid fuel pulverized by the pulverizing roller 33 from accumulating above the intermediate piston 38a and the journal head 31.

[0047] 6 and 8 , the deposition prevention member 37 includes 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 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 along the axis Cf is closed by a 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 made of, for example, a metal material.

[0049] The deposition prevention member 37 is box-shaped and attached to the piston housing 38b so as to leave a gap CL between it and the upper side of the intermediate piston 38a. The deposition prevention member 37 forms a filling space PS with a pair of inclined surfaces 37a1 and 37a2 that allow the solid fuel to fall downward in the vertical direction VD, a surface formed by the plate-shaped members 37b and 37d, and multiple surfaces including the surface of the piston housing 38b. The inclined surfaces 37a1 and 37a2 are arranged so as 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 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 37 is filled with a filling member 37c. The filling member 37c is, for example, a cement-based material. Alternatively, the filling member 37c may be a granular member made of a resin material.

[0051] Next, the deposition prevention member 22 will be described with reference to Figures 9 and 10. Figure 9 is a perspective view of the rotary table 20 shown in Figure 1. Figure 10 is a cross-sectional view of the vicinity of the scraper (moving member) 21 shown in Figure 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 rotary table 20. The scraper 21 is a member that moves the solid fuel F that has accumulated at the bottom of the internal space of the housing 10 toward the drop opening 15 when the scraper 21 rotates around the axis Ch.

[0053] The crusher 100 is equipped with an accumulation prevention member 22 that prevents the solid fuel crushed by the crushing roller 33 from accumulating below the outlet 70 of the crushing table 20 in the vertical direction VD. The accumulation prevention member 22 is a plate-like member that is 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 rotary 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 into 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 , a deposition prevention member 22 is not attached to the scraper 21. Therefore, when large particle size solid fuel F flows in through the gap between the scraper 21 and the lower end of the rotary table 20, it blocks the outlet opening, which is narrower than the inlet opening, and deposition progresses from the blocked area.

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

[0056] Furthermore, according to the pulverizer 100 of this embodiment, the accumulation prevention members 35, 36, and 37 form the filling space PS with multiple surfaces, including an inclined surface. Because the filling space PS is filled with the filling members 35c, 36c, and 37c, even if one of the multiple surfaces is damaged and solid fuel enters the filling space PS, 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 pulverized raw material from accumulating on the crushing roller unit 30 and catching fire, without increasing manufacturing costs.

[0057] According to the crusher 100 of this embodiment, the deposition prevention member 22, which prevents the solid fuel crushed by the crushing roller 33 from accumulating below the outlet 70 of the crushing table 20 in the vertical direction VD, is arranged 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. Because 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 accumulating 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 deposition prevention members 35, 36, and 37 and the target components to prevent the pulverized solid fuel from entering. Furthermore, it is preferable that the plates constituting the deposition prevention members 35, 36, and 37 are joined together without gaps by welding or the like. However, if necessary, bolts or the like may be used to make parts of the members removable.

[0059] The filler material should be heat-resistant as well as wear-resistant, and preferably have fluidity when filled to make it easy to fill, and be self-hardening or heat-hardening after pouring. If air bubbles are trapped during pouring, they will create cavities that can cause buildup at the time of wear and tear, 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 surface facing each other, but it may be increased or decreased 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] Because 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 desirable 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: The crusher (100) according to the 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 crushing table and the table, and 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 has a support shaft (34) for rotating the journal head, and anti-accumulation members (35, 36, 37) for preventing the raw material crushed by the crushing roller from accumulating on the crushing roller unit, and the anti-accumulation members are attached to the vertically upper side of the crushing roller unit and form a filling space (PS) with a plurality of surfaces including inclined surfaces (35a1, 35a2) that cause 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, a deposition 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 deposition 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 deposition prevention member falls vertically downward along the inclined surface, and therefore does not accumulate on the crushing roller unit at the position where the deposition prevention member is installed.

[0064] Furthermore, in the pulverizer according to the first aspect of the present disclosure, the deposition prevention member forms a filling space with multiple surfaces, including an inclined surface. Because the filling space is filled with the filling member, even if one of the multiple surfaces is damaged and raw material enters the filling space, excessive raw material is prevented from entering and accumulating in the filling space. Therefore, a pulverizer can be provided that can prevent the problem of pulverized raw material accumulating inside and catching fire. Furthermore, the deposition prevention effect reduces the risk of fire, allowing the pulverizer to be operated safely even when using inexpensive, low-quality coal such as subbituminous coal or highly flammable solid fuels such as biomass.

[0065] The pulverizer according to the second aspect of the present disclosure is the same as the first aspect, but further includes the following configuration: the filling member is a member made of a mixture of a granular wear-resistant material and a resin material. According to the pulverizer according to the second aspect of the present disclosure, the weight of the deposition prevention member can be reduced by using a member made of a mixture of a granular wear-resistant material 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. The pulverizer according to the third aspect of the present disclosure can be made lighter by using a cement-based material.

[0067] A 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 plurality of surfaces including the inclined surfaces are formed from 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 plurality of surfaces including the inclined surfaces 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 approximately 40 m / s. In addition to drying the raw materials inside the mill, it also guides the ground raw materials through a classifier to the outlet port and transports them to the burner. This transport drying gas contains the raw materials and is blown to various parts at high speed, so parts near the outlet are prone to wear due to erosion, making it necessary to select materials that are wear-resistant. Therefore, it is desirable to use a wear-resistant material for the outer surface of the deposition prevention cover installed near the outlet (where the wind speed exceeds 30 m / s). Specifically, SUS stainless steel, hardfacing steel plate, ceramic-lined steel plate, etc. are preferred.

[0069] The area where abrasion resistance is not required refers to an 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 ordinary carbon steel plate. Specifically, general structural rolled steel such as SS400 can be used.

[0070] A 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 arranged 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 according to the fifth aspect of the present disclosure, since the inclined surface has an angle equal to or greater than the angle of repose of the raw material crushed by the crushing roller, the raw material that falls onto the inclined surface can be reliably dropped downward along the inclined surface.

[0071] A 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 the plurality of surfaces including the inclined surface and the vertically upper surface of the crushing roller unit. According to the crusher according to the sixth aspect of the present disclosure, since the filling space is formed by the vertically upper surface of the crushing roller unit, the vertically upper surface of the crushing roller unit can be used as the surface that forms the filling space.

[0072] A seventh aspect of the present disclosure relates to any one of the first to third aspects of the pulverizer, further comprising the following configuration: The deposition prevention member is disposed vertically above the grinding roller unit, with a gap (CL2) between the surface and the deposition prevention member. According to the seventh aspect of the present disclosure, by disposing the deposition prevention member vertically above the moving components included in the grinding roller unit, with a gap between the surface and the deposition prevention member, it is possible to prevent the deposition prevention member from coming into contact with the moving components and being damaged. The narrower the gap width, the less material accumulates in the clearance. However, if the gap width is too narrow, it may come into contact with moving components and cause abnormal noise, so it is preferable to set the gap width to approximately 5 to 20 mm. While this gap width depends on the ambient temperature and the fuel used, it can be used safely without reaching the layer thickness required for natural oxidation temperature rise.

[0073] A crusher according to an eighth aspect of the present disclosure comprises a crushing table that rotates around an axis, a crushing roller that crushes 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 blows out a carrier 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 table, and a moving member (21) that protrudes in a radial direction perpendicular to the axis and moves the raw material that accumulates at the bottom of the internal space of the housing toward a drop port when the crushing table rotates around the axis is attached to the outer edge of the crushing table, and the deposition prevention member is a plate-like member that is arranged so as 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, which 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. Because the radial gap between the outer edge of the crushing table and the moving member is sealed by the accumulation prevention member, solid fuel is prevented from accumulating in the gap between the outer edge of the crushing table and the moving member.

[0075] A ninth aspect of the present disclosure relates to a pulverizer according to the eighth aspect, further comprising the following configuration. Specifically, the deposition prevention member has an upper surface (22a) that is positioned along a horizontal plane. According to the ninth aspect of the present disclosure, the upper surface of the deposition prevention member is positioned along a horizontal plane. Therefore, when the deposition prevention member rotates in conjunction with the rotation of the grinding table, the raw material can be prevented from coming into contact with the deposition prevention member and being thrown in an undesired direction. If an angle of repose is provided rather than horizontal, the angle of repose acts as a moving member during mill clearing, causing excessive scraping of raw material. Because the excessively scraped and piled-up raw material is tall, it is conceivable that it would reach the height of the air supply duct and be pushed in. Therefore, by not providing an angle of repose, the appropriate amount of raw material can be scraped using only the moving member, preventing accumulation and spontaneous combustion. During normal operation, the angle of repose repels the raw material, preventing it from accumulating in areas that the moving member cannot reach.

[0076] A pulverizer according to a tenth aspect of the present disclosure is the ninth aspect, further comprising the following configuration: A discharge port (23) for discharging the raw material that has entered through the gap is provided below the radial gap between the outer edge portion and the moving member. According to the pulverizer according to the tenth aspect of the present disclosure, even if the raw material has entered the gap, it is possible to prevent the raw material from accumulating in the gap by discharging the raw material through the discharge port.

[0077] DESCRIPTION OF SYMBOLS 10 Housing 11 Opening 12 Roller cover 13 Ceiling portion 13a Exit port 14 Bottom portion 15 Drop port 20 Crushing table 21 Scraper (moving member) 22 Accumulation prevention member 22a Upper surface 23 Discharge port 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 member 35a1, 35a2, 36a1, 36a2, 37a1, 37a2 Inclined surface 35c, 35e, 36c, 37c Filler member 38 Load application 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 Outlet 71 Swirling blade 100 Pulverizer CL, CL2 Clearance Cf, Ch, Cj, Cs Axis F Solid fuel HD Horizontal direction PS Filling space RD Radial direction VD Vertical direction

Claims

1. A crusher comprising: a crushing table which rotates about an axis; and a crushing roller unit which crushes raw material supplied to the crushing table from a raw material supply section between the crushing table and the crushing roller unit, wherein the crushing roller unit has: a journal head attached to a housing; a journal shaft supported by the journal head and extending along the axis; a crushing roller attached to the journal shaft so as to be rotatable about the axis; a support shaft which rotates the journal head; and a deposit prevention member which prevents the raw material crushed by the crushing roller from depositing in the crushing roller unit, wherein the deposit prevention member is attached to the vertical upper side of the crushing roller unit and forms a filling space with a plurality of surfaces including an inclined surface which causes the raw material crushed by the crushing roller to fall vertically downward, and the filling space is filled with a filling member.

2. A pulverizer as claimed in claim 1, wherein said filling member is a mixture of granular wear-resistant material and resin material.

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

4. A crusher according to any one of claims 1 to 3, wherein the plurality of surfaces including the inclined surface are formed from stainless steel, hardfacing steel plate, ceramic lined steel plate, or carbon steel plate.

5. A crusher as claimed in any one of claims 1 to 3, wherein the inclined surface is arranged to have an angle equal to or greater than the angle of repose of the raw material crushed by the crushing roller.

6. A crusher according to any one of claims 1 to 3, wherein the filling space is formed by a plurality of surfaces including the inclined surface and a vertically upper surface of the crushing roller unit.

7. A crusher as claimed in any one of claims 1 to 3, wherein the accumulation prevention member is arranged on the vertically upper side of the crushing roller unit with a gap therebetween.

8. A crusher comprising: a crushing table which rotates about an axis; crushing rollers which crush raw material supplied to the crushing table from a raw material supply unit between the crushing table and the crushing rollers; an outlet provided on the outer periphery of the crushing table and which blows out a conveying gas upward; and a deposit prevention member which prevents the raw material crushed by the crushing rollers from accumulating vertically below the outlet of the crushing rollers, wherein a moving member is attached to the outer edge of the crushing table which protrudes in a radial direction perpendicular to the axis and which moves the raw material which accumulates at the bottom of the internal space of a housing which accommodates the crushing table when the crushing table rotates about the axis toward a drop port, and the deposit prevention member is a plate-like member which is arranged so as to seal the radial gap between the outer edge and the moving member from above in the vertical direction.

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

10. A crusher as set forth in 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.

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