Crusher

Abstract

The present invention provides a crusher that can suppress the entry of foreign matter into the gap formed between the crushing roller and the bracket. [Solution] The crusher comprises a rotary table that rotates around a rotation axis within a housing, a plurality of crushing rollers 3 that crush the material to be crushed between the rotary table and the rotary table, a plurality of brackets 6 that support the crushing rollers 3 so that they can rotate around a roller axis 3A, a pressure frame, a pressure mechanism, a plurality of pivots, and a cover 70 that prevents the material to be crushed from entering the gap CL formed between the crushing rollers 3 and the brackets 6. The brackets 6 have a pair of arm portions 6a, 6b that, when viewed from above, sandwich the vertex 3a of the crushing roller 3 and are positioned such that the vertex 3a is higher than the upper surface 6c of the brackets 6. The cover 70 is positioned above the gap CL so as to include the region R1 through which the roller axis 3A passes when the gap CL is viewed from above in a direction perpendicular to the roller axis 3A.

Description

Technical Field

[0001] The present disclosure relates to a crusher for crushing materials to be crushed such as solid fuel.

Background Art

[0002] As a crusher for solid fuel used in a coal-fired boiler or the like, a vertical crusher is known. The vertical crusher includes a rotating table that rotates within a housing and a plurality of crushing rollers that are pressed onto the rotating table, and crushes materials to be crushed such as coal between the rotating table and the crushing rollers. The crushed particles are blown upward by conveying air introduced from around the rotating table, and fine particles having a predetermined particle size or less are selected by a classification mechanism and sent to a boiler.

[0003] In this type of crusher, the crushing roller is supported by a pressing frame via a bracket so as to be capable of pendulum motion with a pivot as a support shaft. The pressing force applied to the pressing frame is transmitted to the crushing roller via the pivot and the bracket, and presses the crushing roller against the rotating table.

[0004] Regarding the support structure of the crushing roller, a structure is known in which a pair of arm portions are provided on the bracket so as to sandwich the apex of the crushing roller, and the apex of the crushing roller is arranged higher than the top surface (upper surface) of the bracket (see, for example, Patent Document 1). According to this structure, the height of the entire apparatus can be reduced by suppressing the position of the bracket, which contributes to downsizing of the crusher. Further, the swing width of the roller with the pivot provided on the top surface of the bracket as a fulcrum becomes small, which can also contribute to suppression of vibration.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the above structure, the top of the crushing roller is exposed above the top surface of the bracket, leaving the gap between the crushing roller and the bracket open. Therefore, during operation of the crusher, foreign matter such as metal fragments contained in the material being crushed can enter this gap from above. Foreign matter that enters the gap generates chips as the crushing roller rotates, causing wear and damage to various parts such as the bracket. The generated chips may enter and stick to the bearings and seals of the crushing roller, potentially locking the rotation of the crushing roller. Furthermore, the locking of the crushing roller's rotation can cause abnormal vibrations, increased bearing temperature, and cracking of the crushing roller, potentially leading to further serious damage to the vertical crushing apparatus.

[0007] The present disclosure aims to provide a crusher that can suppress the intrusion of foreign matter into the gap formed between the crushing roller and the bracket. [Means for solving the problem]

[0008] A pulverizer according to one aspect of the present disclosure comprises: a rotary table that rotates around a rotation axis within a housing; a plurality of pulverizing rollers that pulverize a material to be pulverized between the rotary table and the pulverizing rollers; a plurality of brackets that rotatably support the pulverizing rollers around their roller axes; a pressure frame to which the plurality of brackets are attached such that the plurality of pulverizing rollers are arranged at predetermined intervals along the rotation direction of the rotary table; a pressure mechanism that applies a pressing force to the pressure frame to press the pulverizing rollers toward the rotary table; a plurality of pivots arranged between the pressure frame and the brackets so that the pulverizing rollers and the brackets can move together as a pendulum in the radial direction of the rotary table; and a cover that prevents the material to be pulverized from entering the gap formed between the pulverizing rollers and the brackets, wherein the brackets have a pair of arm portions that, when viewed from above, sandwich the apex of the pulverizing rollers and are arranged such that the apex is higher than the upper surface of the brackets, and the cover is positioned above the gap such that, when viewed from above in a direction perpendicular to the roller axis, it includes the region through which the roller axis passes. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide a crusher that can suppress the intrusion of foreign matter into the gap formed between the crushing roller and the bracket. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of a pulverizer according to one embodiment of the present disclosure. [Figure 2] Figure 1 is a magnified view of the grinding section, showing it with the cover removed. [Figure 3] Figure 2 is a plan view of the crushing section along the first direction, which coincides with the height direction. [Figure 4] This figure shows the crushing section as viewed along a second direction perpendicular to the roller axis. [Figure 5] This is a plan view showing the crushing section with the cover attached, as shown in Figure 3. [Figure 6]This figure shows the crushing section shown in Figure 4 with a cover attached. [Figure 7] Figure 6 shows the cover as viewed from a third direction perpendicular to the height direction. [Figure 8] This is a view of the cover relating to the first modified example from a third direction. [Figure 9] This is a plan view of the crushing section with the cover according to the second modified example attached, viewed along the first direction. [Figure 10] This is a diagram showing the crushing section with the cover according to the second modified example attached, viewed along the second direction. [Figure 11] This is a plan view of the crushing section with the cover attached according to the third modified example, viewed along the first direction. [Figure 12] This is a diagram showing the crushing section with the cover attached according to the third modified example, viewed along the second direction. [Modes for carrying out the invention]

[0011] Embodiments of this disclosure will be described below with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and redundant descriptions may be omitted.

[0012] (Overall configuration of the crusher) Figure 1 is a schematic diagram of a crusher 100 according to one embodiment of the present disclosure. The crusher 100 is a vertical crushing device that crushes solid fuels such as coal as the material to be crushed, and comprises a drive unit A, a crushing unit B, a classification unit C, and a distribution unit D.

[0013] The drive unit A includes a reduction gear 50 and a drive motor 51. The drive motor 51 rotates the rotary table 2 around the rotation axis Z in a predetermined direction via the reduction gear 50.

[0014] The crushing section B is arranged inside the housing 46 and has a rotating table 2, a plurality of crushing rollers 3, a plurality of brackets 6, a pressurizing frame 5, a plurality of pivots 7, a pressurizing rod 8, and a hydraulic cylinder 9. The material to be crushed 60 such as coal supplied from the coal feeding pipe 1 drops onto the central part of the rotating table 2. The material to be crushed 60 that has dropped onto the rotating table 2 moves on the rotating table 2 from the central part toward the outer peripheral part by the centrifugal force accompanying the rotation of the rotating table 2, and is caught between the rotating table 2 and the crushing rollers 3 and crushed.

[0015] The crushing load generated by the hydraulic cylinder 9 is transmitted from the outside of the housing 46 to the pressurizing frame 5 through the pressurizing rod 8. The crushing load transmitted to the pressurizing frame 5 is transmitted to the crushing rollers 3 via the pivots 7 and the brackets 6, and presses the crushing rollers 3 against the rotating table 2. That is, the pressurizing rod 8 and the hydraulic cylinder 9 function as a pressurizing mechanism that applies a pressing force to press the crushing rollers 3 against the rotating table 2 to the pressurizing frame 5.

[0016] The crushed material to be crushed is blown upward by the primary air (transport air) 61 introduced from the throat 42 provided around the rotating table 2. The primary air 61 is introduced into the throat 42 from the side surface of the primary air wind box 41 through the primary air duct 40, rectified in the primary air wind box 41, and then ejected from the throat 42.

[0017] Between the housing 46 and the throat 42, an inclined member 47 is provided which is connected to the inner wall of the housing 46 and has a structure that descends from the housing 46 toward the throat 42 side. A plurality of gas ejection holes 68 are installed along the circumferential direction in the inclined member 47 so as to eject the primary air toward the center direction of the crusher 100. Among the blown-up particle group 62, those with a relatively large particle size are returned to the crushing section B by gravity on the way to being conveyed to the classification section C and crushed again, and those with a relatively small particle size become the rising particles 69 and are conveyed to the classification section C.

[0018] Classification section C comprises a fixed classification mechanism 10 and a rotary classification mechanism 20. The fixed classification mechanism 10 includes a collection cone 11 and a plurality of fixed fins 12. In the process of guiding the particle group 65 from the outer circumference to the inner circumference of the fixed fins 12, relatively large particles among the rising particles 69 that reach the fixed classification mechanism 10 collide with the fixed fins 12 and are repelled, and returned to the pulverization section B by gravity and pulverized again. On the other hand, relatively small particles pass between the fixed fins 12 and are guided to the rotary classification mechanism 20.

[0019] The rotary classification mechanism 20 has a classifier motor 23 and a plurality of rotating fins 21, and the classifier motor 23 rotates the plurality of rotating fins 21 around a rotation axis 22. In the process of guiding fine particles 67 from the outer circumference to the inner circumference of the rotating fins 21, coarse particles 63 larger than a predetermined particle size from the group of particles 65 guided to the rotary classification mechanism 20 collide with the rotating fins 21 and are repelled, and returned to the pulverization section B by gravity and pulverized again. On the other hand, fine particles 67 smaller than the predetermined particle size pass between the rotating fins 21 and are conveyed to the distribution section D.

[0020] The distribution section D includes a distributor 30. The fine particles 67 that have passed through the classification section C are distributed in the distributor 30 to a plurality of coal supply pipes 31 and sent as product fine powder 64 to a combustion device such as a coal-fired boiler (not shown).

[0021] (Detailed structure of the grinding section) Figure 2 is a magnified view of the crushing section B shown in Figure 1, with the cover 70 (described later) removed. Figure 3 is a plan view of the crushing section B shown in Figure 2, viewed from above along the first direction DR1, which coincides with the height direction. Figure 4 is a view of the crushing section B shown in Figure 2, viewed along the second direction DR2, which is perpendicular to the central axis CX of the roller shaft 3A.

[0022] The crushing roller 3 has a tire-like outer shape and is configured to rotate around the roller axis 3A. The roller axis 3A of the crushing roller 3 is inclined with respect to the horizontal direction. That is, the crushing roller 3 is positioned such that its central axis CX is inclined from above toward the rotation axis Z of the rotary table 2 from the outer circumference side of the rotary table 2. This inclination is called a negative camber angle. When the rotary table 2 rotates, the crushing roller 3 rotates in response via the rotary table 2 or the material to be crushed 60 on the rotary table 2, and the material to be crushed 60 is caught between the rotary table 2 and the crushing roller 3 and crushed.

[0023] The bracket 6 is a member that supports the crushing roller 3 so that it can rotate around the roller axis 3A. As shown in Figure 3, the bracket 6 has a pair of arm portions, namely a first arm portion 6a and a second arm portion 6b, which are arranged on both sides in the width direction WD perpendicular to the roller axis 3A with respect to the central axis CX of the roller axis 3A. The first arm portion 6a and the second arm portion 6b are arranged so as to sandwich the vertex 3a of the crushing roller 3 when viewed from above.

[0024] As shown in Figure 2, the apex 3a of the crushing roller 3 is positioned higher in the height direction HD than the upper surface 6c of the bracket 6. That is, the pair of arm sections (first arm section 6a, second arm section 6b) are positioned to sandwich the middle portion of the outer surface of the crushing roller 3 from both sides, such that the apex 3a of the crushing roller 3 protrudes above the upper surface 6c of the bracket 6. This arrangement reduces the height dimension of the bracket 6, contributing to a reduction in the overall height and miniaturization of the crusher 100.

[0025] A first pivot mounting portion 6aA is provided at the tip of the first arm portion 6a, and a second pivot mounting portion 6bA is provided at the tip of the second arm portion 6b. Pivots 7 are positioned at the first pivot mounting portion 6aA and the second pivot mounting portion 6bA, respectively. The pivots 7 are interposed between the pressurizing frame 5 and the bracket 6, connecting them so that the crushing roller 3 and the bracket 6 can move together as a pendulum in the radial direction RD of the rotary table 2.

[0026] The pressure frame 5 is an annular or frame-shaped member on which multiple brackets 6 are attached at predetermined intervals along the rotational direction of the rotary table 2, and supports multiple crushing rollers 3 collectively. The pressing force applied to the pressure frame 5 via the pressure rod 8 by the hydraulic cylinder 9 is transmitted to each bracket 6 via the pivot 7, pressing each crushing roller 3 against the rotary table 2.

[0027] In a structure where the apex 3a of the crushing roller 3 protrudes above the upper surface 6c of the bracket 6, a gap CL is formed between the outer circumferential surface of the crushing roller 3 and the upper surface 6c of the bracket 6. This gap CL extends along the circumferential direction of the crushing roller 3 between the first arm portion 6a and the second arm portion 6b. As shown in Figure 4, the region R1 through which the roller shaft 3A passes in the gap CL is in communication with the through-shaft seal portion inside the crushing roller 3. Therefore, if foreign matter enters this region R1, there is a particularly high risk of the foreign matter reaching the seal portion.

[0028] (Cover composition) Figure 5 is a plan view showing the crushing section B shown in Figure 3 with the cover 70 attached. Figure 6 is a diagram showing the crushing section B shown in Figure 4 with the cover 70 attached. Figure 7 is a view of the cover 70 shown in Figure 6 from a third direction DR3 perpendicular to the height direction.

[0029] The cover 70 is a component that prevents the material to be crushed or foreign matter from entering the gap CL formed between the crushing roller 3 and the bracket 6. The cover 70 is attached to the upper surface 6c of the bracket 6 and is positioned between a pair of arm portions (first arm portion 6a, second arm portion 6b) to cover the entire upper part of the gap CL.

[0030] As shown in Figure 6, the cover 70 is positioned above the gap CL such that it includes the region R1 through which the roller shaft 3A passes when the gap CL is viewed from a second direction DR2 perpendicular to the central axis CX of the roller shaft 3A. This prevents the material to be crushed and foreign matter falling from above during the operation of the crusher 100 from reaching the seal portion via region R1.

[0031] In this embodiment, the cover 70 is constructed by connecting a plurality of flat plate-shaped members that are arranged to partially cover the outer circumference of the crushing roller 3. Specifically, the cover 70 has three plate-shaped members: a first plate-shaped member 71, a second plate-shaped member 72, and a third plate-shaped member 73. The first plate-shaped member 71 is a central plate-shaped member that covers the area above the gap CL near the apex 3a of the crushing roller 3. The second plate-shaped member 72 is a plate-shaped member that is positioned adjacent to the first plate-shaped member 71 on one side in the width direction WD (the first arm portion 6a side). The third plate-shaped member 73 is a plate-shaped member that is positioned adjacent to the first plate-shaped member 71 on the other side in the width direction WD (the second arm portion 6b side).

[0032] The first plate-shaped member 71 and the second plate-shaped member 72 are connected by the first connecting line 70a. The first plate-shaped member 71 and the third plate-shaped member 73 are connected by the second connecting line 70b. Both the first connecting line 70a and the second connecting line 70b extend in a direction parallel to the upper surface 6c of the bracket 6 (third direction DR3). The three plate-shaped members (first plate-shaped member 71, second plate-shaped member 72, and third plate-shaped member 73) are bent along the first connecting line 70a and the second connecting line 70b to form a three-dimensional shape along the outer circumferential surface of the crushing roller 3.

[0033] As shown in Figure 7, the angle between a pair of adjacent plate-shaped members is obtuse. Specifically, the angle θ1 between the first plate-shaped member 71 and the second plate-shaped member 72 at the first connecting line 70a is obtuse, and the angle θ2 between the first plate-shaped member 71 and the third plate-shaped member 73 at the second connecting line 70b is also obtuse. By making the angle between adjacent plate-shaped members obtuse, the gap between the cover 70 and the crushing roller 3 can be reduced, effectively suppressing the entry of foreign matter into the gap CL. Furthermore, crushed material and foreign matter are less likely to accumulate on the outer surface of the cover 70, and crushed material and foreign matter that fall onto the upper surface of the cover 70 slide off quickly due to their own weight.

[0034] The cover 70 is made of a plate material. The plate material that makes up the cover 70 is a metal plate such as a steel plate. The cover 70 is attached to the bracket 6 in a removable manner by means of bolt fastening or the like. The fact that the cover 70 is removable makes it easy to replace the cover 70 when it wears out, or to remove the cover 70 for maintenance and inspection of the crushing roller 3.

[0035] (Effects of the embodiment) The configuration of the embodiment described above provides the following effects.

[0036] The crusher 100 is equipped with a cover 70 to prevent material to be crushed from entering the gap CL formed between the crushing roller 3 and the bracket 6. The bracket 6 has a pair of arm portions (first arm portion 6a, second arm portion 6b) that, when viewed from above, sandwich the apex 3a of the crushing roller 3 and are positioned such that the apex 3a is higher than the upper surface 6c of the bracket 6. The cover 70 is positioned above the gap CL such that, when viewed from above from a direction perpendicular to the central axis CX of the roller shaft 3A, it includes the region R1 through which the roller shaft 3A passes. With this configuration, even if the apex 3a of the crushing roller 3 protrudes above the upper surface 6c of the bracket 6, the region R1 in the gap CL that is highly likely to communicate with the seal portion is covered from above by the cover 70. This prevents foreign matter in the material to be crushed that falls from above during operation of the crusher 100 from entering the gap CL and reaching the seal portion, thereby preventing malfunction of the crushing roller 3.

[0037] The cover 70 is constructed by connecting multiple flat plate-shaped members (first plate-shaped member 71, second plate-shaped member 72, third plate-shaped member 73) that are arranged to partially cover the outer circumference of the crushing roller 3. This configuration allows for the easy manufacture of a three-dimensional cover 70 that conforms to the outer surface of the crushing roller 3 simply by bending and connecting the flat plate-shaped members, thereby reducing the manufacturing cost of the cover 70.

[0038] The angle θ1 formed by a pair of adjacent plate-shaped members (first plate-shaped member 71, second plate-shaped member 72) is obtuse. This configuration forms a gently sloping surface on the outer surface of the cover 70, allowing crushed material and foreign objects that fall onto the upper surface of the cover 70 to slide off quickly due to their own weight, thereby suppressing the accumulation of crushed material and foreign objects on the cover 70.

[0039] The cover 70 is detachably attached to the bracket 6. This configuration makes it easy to replace the cover 70 when it wears out, and to remove the cover 70 for maintenance and inspection of the crushing roller 3, thereby improving maintainability.

[0040] The cover 70 is made of sheet metal. This configuration allows the cover 70 to be formed with a simple structure, contributing to reduced manufacturing costs and weight.

[0041] The roller shaft 3A is inclined with respect to the horizontal direction. This configuration ensures an appropriate meshing angle between the crushing roller 3 and the rotary table 2 on the outer circumference of the rotary table 2, improving the crushing efficiency of the material to be crushed. Furthermore, because the roller shaft 3A is inclined, if the cover 70 is not provided, foreign matter tends to accumulate in the gap CL directly above the roller shaft 3A. However, by providing the cover 70, the risk of foreign matter accumulation caused by this inclined arrangement can be effectively suppressed.

[0042] The cover 70 is positioned between the pair of arm sections (first arm section 6a, second arm section 6b) to cover the entire upper part of the gap CL. This configuration prevents foreign matter from entering from above throughout the entire gap CL, thereby comprehensively suppressing the entry of foreign matter not only into the area R1 through which the roller shaft 3A passes but also into the entire gap CL, maximizing the foreign matter intrusion prevention effect.

[0043] The material to be pulverized is a solid fuel. In the pulverization of solid fuels, foreign matter such as metal fragments may be mixed into the fuel, so the effect of preventing the intrusion of foreign matter by the cover 70 is particularly significant.

[0044] <First variation> Figure 8 is a view of the cover 70A according to the first modified example, as seen from the third direction DR3. The cover 70A according to the first modified example is a member that covers the gap CL, positioned above the gap CL and including the region R1 through which the roller shaft 3A passes, similar to the cover 70 according to the above embodiment, but its shape differs from that of the above embodiment.

[0045] The cover 70A has a curved shape that partially covers the outer periphery of the crushing roller 3. Specifically, the cover 70A is composed of a single curved plate that curves along the outer periphery of the crushing roller 3. The curved shape of the cover 70A has a curvature that corresponds to the curvature of the outer periphery of the crushing roller 3, and covers the area above the gap CL while maintaining a substantially uniform distance between it and the outer periphery of the crushing roller 3.

[0046] The curved shape of the cover 70A reduces the gap between the cover 70 and the crushing roller 3, effectively suppressing the entry of foreign matter into the gap CL. Furthermore, the material to be crushed and foreign matter that falls onto the outer surface of the cover 70A flows smoothly along the curved surface, thus suppressing the accumulation of material to be crushed and foreign matter on the cover 70A. In addition, the curved shape reduces stress concentration, improving the durability of the cover 70A when material to be crushed or foreign matter collides with it during the operation of the crusher 100.

[0047] <Second variation> Figure 9 is a plan view of the crushing section B with the cover 70B of the second modified example attached, viewed along the first direction DR1. Figure 10 is a view of the crushing section B with the cover 70B of the second modified example attached, viewed along the second direction DR2.

[0048] The cover 70B according to the second modified example has a configuration that covers only a portion of the upper part of the gap CL between the pair of arm portions, whereas the cover 70 according to the above embodiment covers the entire upper part of the gap CL between the pair of arm portions. Specifically, the cover 70B is positioned between the pair of arm portions (first arm portion 6a, second arm portion 6b) to cover only a portion of the upper part of the gap CL, which includes the region R1 through which the roller shaft 3A passes.

[0049] The cover 70B is a plate-shaped member that extends with a predetermined width on both sides in the width direction WD, sandwiching the central axis CX of the roller shaft 3A, and is detachably attached to the upper surface 6c of the bracket 6. The width direction WD dimension of the cover 70B is smaller than the width direction WD dimension of the cover 70 according to the above embodiment.

[0050] Compared to the cover 70 according to the above embodiment, the cover 70B has a smaller surface area, thus reducing the manufacturing cost and weight of the cover 70B, and making it easy to retrofit to existing crushers. On the other hand, the cover 70B reliably covers the area R1 through which the roller shaft 3A, which is most likely to enter the seal, passes, thus efficiently providing a foreign matter intrusion prevention effect.

[0051] <Third variation> Figure 11 is a plan view of the grinding section B with the cover 70C of the third modified example attached, viewed along the first direction DR1. Figure 12 is a view of the grinding section B with the cover 70C of the third modified example attached, viewed along the second direction DR2.

[0052] The cover 70C according to the third modified example is a member positioned between the crushing roller 3 and the bracket 6 inside the gap CL, rather than above the gap CL. As shown in Figure 11, the cover 70C is attached to the inner surface of the bracket 6 (the surface facing the crushing roller 3) at a position that includes the central axis CX of the roller shaft 3A. As shown in Figure 12, the cover 70C is positioned to include the region R1 through which the roller shaft 3A passes when the gap CL is viewed from a plan view from a second direction DR2 perpendicular to the central axis CX of the roller shaft 3A.

[0053] The cover 70C functions as a baffle plate that blocks the path of foreign matter that enters the gap CL from above to reach the seal portion of the roller shaft 3A. When foreign matter enters the gap CL, it comes into contact with the cover 70C, its path is altered, and it is more easily discharged outside the seal portion. As a result, even if foreign matter enters the gap CL, its arrival at the seal portion is suppressed, and malfunction of the crushing roller 3 can be prevented.

[0054] (Other variations) This disclosure is not limited to the embodiments and variations described above. For example, the following modifications are possible.

[0055] In the above embodiment, an example was shown in which the cover 70 is constructed by connecting three plate-like members (first plate-like member 71, second plate-like member 72, third plate-like member 73), but the number of plate-like members is not limited to three. It may be constructed by connecting two plate-like members, or by connecting four or more plate-like members. By increasing the number of plate-like members, the outer surface shape of the cover can be made to more closely approximate the outer surface of the crushing roller 3. Furthermore, the cover 70 is not limited to being constructed by connecting multiple plate-like members. For example, a single plate material may be bent to form a three-dimensional shape that conforms to the outer surface of the crushing roller 3.

[0056] In the above embodiment, an example was shown in which the cover 70 is detachably attached to the bracket 6 by bolt fastening, but the method of attaching the cover is not limited to this. For example, the cover may be fixed to the bracket 6 by welding. Alternatively, the cover may be attached to the bracket 6 by fastening means such as clips, pins, or hooks.

[0057] In the above embodiment, an example was shown in which the plate material constituting the cover 70 is a metal plate such as a steel plate, but the material of the cover is not limited to this. For example, the cover may be made of a ceramic material with excellent wear resistance, a cemented carbide, or a heat-resistant resin material.

[0058] In the above embodiment, an example was shown where the material to be pulverized is a solid fuel such as coal, but the material to be pulverized is not limited to solid fuels. For example, the pulverizer of this disclosure may be applied to pulverize various materials such as cement raw materials, new material raw materials, and biomass.

[0059] The configurations of the above embodiments and each modified example can be combined as appropriate within the limits of what is technically consistent. For example, the curved cover 70A according to the first modified example may be configured to cover only a portion of the upper part of the gap CL, as in the second modified example.

[0060] The crusher (100) described in each embodiment above can be understood, for example, as follows.

[0061] A first aspect of the present disclosure includes a rotating table (2) that rotates around a rotation axis (Z) within a housing (46), a plurality of grinding rollers (3) that grind a material to be ground between themselves and the rotating table, a plurality of brackets (6) that rotatably support the grinding rollers around a roller axis (3A), a pressure frame (5) to which the plurality of brackets are attached so that the plurality of grinding rollers are arranged at predetermined intervals along the rotation direction of the rotating table, a pressure mechanism (8,9) that applies a pressing force to the pressure frame to press the grinding rollers toward the rotating table, and the grinding rollers and the brackets are integrated together to form the rotating table The crusher comprises a plurality of pivots (7) positioned between the pressurizing frame and the bracket so as to be pendulum-like in the radial direction (RD) of the cable, and a cover (70) that prevents material to be crushed from entering the gap (CL) formed between the crushing roller and the bracket, wherein the bracket has a pair of arm portions (6a, 6b) positioned to sandwich the apex (3a) of the crushing roller when viewed from above, and such that the apex is higher than the upper surface (6c) of the bracket, and the cover is positioned above the gap so as to include the region (R1) through which the roller axis passes when the gap is viewed from above in a direction perpendicular to the roller axis. According to the first aspect of the present disclosure, even if the apex of the crushing roller protrudes above the upper surface of the bracket, the area in the gap that is likely to communicate with the seal portion is covered from above by the cover, so that foreign matter falling from above during operation of the crusher can be prevented from entering the gap and reaching the seal portion, thereby preventing malfunction of the crushing roller.

[0062] In the second aspect of the present disclosure, the crusher, in the first aspect, is configured such that the cover is formed by connecting a plurality of flat plate-shaped members (71, 72, 73) that are arranged to partially cover the outer circumference of the crushing roller. According to the second aspect of the present disclosure, a three-dimensional cover that conforms to the outer surface of the crushing roller can be easily manufactured by simply bending and connecting flat plate-shaped members, thereby reducing the manufacturing cost of the cover.

[0063] In the third aspect of the present disclosure, the crusher, in the second aspect, has an obtuse angle (θ1) between a pair of adjacent plate-shaped members (71, 72). According to the third aspect of the present disclosure, the outer surface of the cover forms a gently sloping surface, and the material to be crushed and foreign matter that falls onto the upper surface of the cover slides off quickly due to their own weight, thereby suppressing the accumulation of material to be crushed and foreign matter on the cover.

[0064] In the fourth aspect of the present disclosure, the crusher, in the first aspect, has a curved shape that partially covers the outer circumference of the crushing roller. According to the fourth aspect of the present disclosure, the material to be crushed and foreign matter that falls onto the outer surface of the cover flows smoothly along the curved surface, thereby suppressing the accumulation of material to be crushed and foreign matter on the cover, and the durability of the cover is improved because stress concentration is reduced by the curved shape.

[0065] In the fifth aspect of the present disclosure, the crusher, in the first aspect, has the cover detachably attached to the bracket. According to the fifth aspect of the present disclosure, maintenance is improved by making it easier to replace the cover when it wears out or to remove the cover for maintenance and inspection of the crushing rollers.

[0066] In the sixth aspect of this disclosure, the crusher, in the first aspect, has a cover made of plate material. According to the sixth aspect of this disclosure, the cover can be formed with a simple structure, contributing to reduced manufacturing costs and weight.

[0067] In the seventh aspect of this disclosure, the pulverizer, in the first aspect, has a roller shaft that is inclined with respect to the horizontal direction. According to the seventh aspect of this disclosure, an appropriate meshing angle is ensured between the pulverizing roller and the rotary table on the outer circumference of the rotary table, improving the pulverizing efficiency of the material to be pulverized. In addition, the risk of foreign matter accumulating in the gap caused by the inclined roller shaft can be effectively suppressed by the cover.

[0068] In the eighth aspect of the present disclosure, the crusher, in the first aspect, is positioned so as to cover the entire area above the gap between the pair of arm portions. According to the eighth aspect of the present disclosure, foreign matter intrusion from above is prevented throughout the entire gap, thereby maximizing the effect of preventing foreign matter intrusion.

[0069] In the ninth aspect of the present disclosure, in the first aspect, the cover (70B) is positioned to cover only a portion of the gap between the pair of arm portions, including the area through which the roller shaft passes. The ninth aspect of the present disclosure allows for a reduction in the area of ​​the cover, thereby reducing manufacturing costs and weight, and effectively prevents foreign matter from entering the seal by reliably covering the area through which the roller shaft passes, which is most likely to be exposed to foreign matter.

[0070] In the first embodiment of the pulverizer according to the tenth aspect of this disclosure, the material to be pulverized is a solid fuel. According to the pulverizer according to the tenth aspect of this disclosure, since foreign matter such as metal fragments may be mixed into the fuel during the pulverization of solid fuel, the effect of preventing the intrusion of foreign matter by the cover is particularly pronounced. [Explanation of Symbols]

[0071] 1. Coal supply pipe 2 Rotating Tables 3. Crushing roller 3a Vertex 3A Roller shaft 5. Pressure Frame 6 brackets 6a First arm section 6aA First pivot mounting section 6b Second Arm Section 6bA Second pivot mounting section 6c Top 7. Pivot 8 Pressure Rod 9 Hydraulic Cylinder 10 Fixed classification mechanism 11. Collection cones 12 fixed fins 20 Rotary Classification Mechanism 21 Rotating Fins 22 Rotation axis 23 Classification motor 30 distributor 31 Coal pipe 40 Primary air duct 41 Primary air windbox 42 Throat 46 Housing 47 Inclined member 50 reducer 51 Drive motor 60 Material to be crushed 61 Primary air 62 Particle group 63 Coarse particles 64 Product fine powder 65 Particle group 67 Fine particles 68 Gas outlets 69 Rising particles 70, 70A, 70B, 70C Cover 70a 1st connection line 70b 2nd connection line 71 First plate-shaped member 72 Second plate-shaped member 73 Third plate-shaped member 100 Crusher A Drive Unit B. Grinding section C Classifying section CL gap CX center axis D Distribution section DR1 1st direction DR2 2nd direction DR3 3rd direction HD Height Direction R1 area RD Radial direction WD width direction Z axis of rotation Angle between θ1 and θ2

Claims

1. A rotary table that rotates around a pivot axis inside the housing, A plurality of grinding rollers that grind the material to be ground between themselves and the aforementioned rotating table, Multiple brackets that support the aforementioned crushing roller so as to be rotatable around the roller axis, A pressure frame to which multiple brackets are attached such that multiple crushing rollers are arranged at predetermined intervals along the rotational direction of the rotary table, A pressurizing mechanism that applies a pressing force to the pressurizing frame to press the crushing roller toward the rotating table, A plurality of pivots are arranged between the pressurizing frame and the bracket so that the crushing roller and the bracket can move together as a pendulum in the radial direction of the rotating table, The system includes a cover that prevents the material to be crushed from entering the gap formed between the crushing roller and the bracket, The bracket has a pair of arm portions that, when viewed from above, sandwich the apex of the crushing roller and are positioned such that the apex is higher than the upper surface of the bracket. The cover is positioned above the gap of the crusher such that it includes the region through which the roller shaft passes when the gap is viewed in plan from a direction perpendicular to the roller shaft.

2. The crusher according to claim 1, wherein the cover is configured by connecting a plurality of flat plate-shaped members that are arranged to partially cover the outer circumference of the crushing roller.

3. The crusher according to claim 2, wherein the angle between the pair of adjacent plate-like members is an obtuse angle.

4. The crushing machine according to claim 1, wherein the cover has a curved shape that partially covers the outer circumference of the crushing roller.

5. The crusher according to claim 1, wherein the cover is detachably attached to the bracket.

6. The crusher according to claim 1, wherein the cover is made of a plate material.

7. The crusher according to claim 1, wherein the roller shaft is inclined with respect to the horizontal direction.

8. The crusher according to claim 1, wherein the cover is arranged between the pair of arm portions to cover the entire area above the gap.

9. The crusher according to claim 1, wherein the cover is arranged to cover only a portion above the gap between the pair of arm portions, including the region through which the roller shaft passes.

10. The pulverizer according to claim 1, wherein the material to be pulverized is a solid fuel.

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