Vertical mill

Abstract

The vertical mill 100 comprises a housing 110 including a cylindrical main body 112, an opening 116 formed on the side surface 112b of the main body, and a cover 118 that closes the opening and protrudes outward from the main body; a roller unit 130 provided within the housing, including a grinding table 120 provided within the main body of the housing, a grinding roller 132 rotatably provided above the grinding table within the main body of the housing, a roller shaft 134 that rotatably supports the grinding roller, and a bracket 136 through which the roller shaft is inserted and which is partly provided within the cover of the housing; a pressurizing device 140 that penetrates the cover of the housing and presses the bracket of the roller unit toward the grinding table; and a covering plate 200 provided on the main body side of the housing cover and covering at least a part of the opening of the housing.

Description

Technical Field

[0001] The present disclosure relates to a vertical mill. This application claims the benefit of priority based on Japanese Patent Application No. 2024-148188 filed on August 30, 2024, the content of which is incorporated herein by reference.

Background Art

[0002] Vertical mills for grinding materials such as coal, biomass, and cement raw materials are widespread. A vertical mill includes a grinding table, grinding rollers, and an air flow forming section. In a vertical mill, the material to be ground is supplied between the grinding table and the grinding rollers. Then, the material to be ground is crushed by being pressed by the grinding rollers on the grinding table. Also, in a vertical mill, an upward air flow is formed from the grinding table toward the discharge port by the air flow forming section. For this reason, the crushed material to be ground rides on the upward air flow and moves from the grinding table to the discharge port, and is discharged outside the vertical mill through the discharge port.

[0003] As such a vertical mill, for example, Patent Document 1 discloses a vertical mill including a roller unit including grinding rollers and a biasing device that applies a load to the roller unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As shown in the above Patent Document 1, in a vertical mill, a part of the housing protrudes outward to accommodate the rods and rod folders constituting the roller unit, and the arms constituting the biasing device.

[0006] The protruding portion of the housing has a larger cross-sectional area of ​​the airflow path (flow path cross-sectional area) compared to the rest of the housing. As a result, the velocity of the rising airflow decreases in the protruding portion of the housing. This leads to a problem in vertical mills where the amount of material to be ground per unit time decreases.

[0007] In view of these challenges, this disclosure aims to provide a vertical mill capable of preventing a decrease in the amount of material to be ground per unit time. [Means for solving the problem]

[0008] To solve the above problems, a vertical mill according to one aspect of the present disclosure includes a housing that includes a cylindrical main body, an opening formed on the side of the main body, and a cover that closes the opening and protrudes outward from the main body; a grinding table provided inside the main body of the housing; a grinding roller rotatably provided above the grinding table inside the main body of the housing; a roller shaft that rotatably supports the grinding roller; and a bracket through which the roller shaft is inserted, with a portion of which is provided inside the cover of the housing; and a pressurizing device that penetrates the cover of the housing and presses the bracket of the roller unit toward the grinding table. An airflow forming unit that forms an airflow from an outlet located on or outside the outer edge of the grinding table toward an outlet formed above the grinding rollers in the housing, The housing includes a covering plate provided on the main body side of the housing cover, which covers at least a portion of the opening of the housing. The covering plate covers an area from the upper edge of the housing opening to more than 50% of the vertical length of the opening. .

[0009] The covering plate may also be fixed to the housing cover. Alternatively, the covering plate may be provided inside the housing cover. Furthermore, the surface of the covering plate facing inward into the housing may be flush with the inner circumferential surface of the main body of the housing, or it may be positioned on the cover side of the inner circumferential surface of the main body of the housing. Furthermore, the vertical mill described above may be equipped with a flexible and heat-resistant filler material that fills the space formed between the cover and the covering plate.

[0010] Furthermore, the covering plate may have a first opening into which a pressurizing device is fitted.

[0011] Furthermore, the covering plate may have a second opening into which the bracket of the roller unit is fitted.

[0012] Furthermore, the covering plate may cover at least the upper part of the opening in the housing. [Effects of the Invention]

[0013] According to this disclosure, it is possible to prevent a decrease in the amount of material to be pulverized per unit time. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a schematic diagram of a vertical mill according to an embodiment of the present disclosure. [Figure 2] Figure 2 is a magnified view of a portion of Figure 1. [Figure 3] Figure 3 is a front view of the covering plate according to the same embodiment. [Figure 4] Figure 4 is a front view of the accumulation prevention plate according to the same embodiment. [Modes for carrying out the invention]

[0015] Embodiments of this disclosure will be described in detail below with reference to the attached drawings. The dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for the purpose of facilitating understanding and do not limit this disclosure unless otherwise specified. In this specification and in the drawings, elements having substantially the same function or configuration are denoted by the same reference numerals to avoid redundant explanations. Elements not directly related to this disclosure are omitted from the illustrations.

[0016] [1. Overview of the vertical mill] First, referring to FIG. 1, an overview of the vertical mill 100 according to an embodiment of the present disclosure will be described. FIG. 1 is a schematic view of the vertical mill 100 according to this embodiment. In FIG. 1, solid arrows indicate the flow of the material to be crushed and the solid-gas two-phase flow. Also, in FIG. 1, dashed arrows indicate the gas flow. In the following figures including FIG. 1 of this embodiment, the X-axis, Y-axis, and Z-axis that intersect perpendicularly are defined as shown. The X-axis and Y-axis indicate the horizontal direction, and the Z-axis indicates the vertical direction.

[0017] As shown in FIG. 1, the vertical mill 100 according to this embodiment includes, for example, a housing 110, a grinding table 120, one or more roller units 130, one or more pressurizing devices 140, a supply pipe 150, a discharge port 160, a blowing port 170, an air flow forming section 180, a rotary classifier 190, and a covering plate 200. In FIG. 1, for ease of understanding, only one roller unit 130 and one pressurizing device 140 are shown, and other roller units 130 and pressurizing devices 140 are omitted.

[0018] The housing 110 is cylindrical. The housing 110 is, for example, substantially cylindrical. The housing 110 is provided such that the axial direction of the housing 110 is along the vertical direction or substantially the vertical direction.

[0019] The housing 110 includes a main body portion 112, a distribution portion 114, an opening 116, and a cover 118. The main body portion 112 is cylindrical. The main body portion 112 is, for example, substantially cylindrical. The inner diameter of the main body portion 112 is substantially constant in the vertical direction. The distribution portion 114 communicates with the upper part of the main body portion 112. The inner diameter of the distribution portion 114 gradually increases from bottom to top. That is, the flow path cross-sectional area of the distribution portion 114 gradually increases from bottom to top. The communication location 112a between the main body portion 112 and the distribution portion 114 is, for example, smaller than the inner diameter of the main body portion 112.

[0020] The opening 116 is formed on the side surface 112b of the main body 112. The opening 116 is formed, for example, above the grinding table 120 in the main body 112. The size of the opening 116 is such that the roller unit 130 and the pressurizing device 140, which will be described later, can be inserted through it.

[0021] The cover 118 is also called the journal cover. The cover 118 closes the opening 116. The cover 118 protrudes outward from the main body 112. The cover 118 is configured to open and close the opening 116, for example. In this embodiment, the cover 118 opens and closes the opening 116 by rotating about a pivot axis 118a. The pivot axis 118a extends, for example, horizontally or substantially horizontally.

[0022] The grinding table 120 is installed within the main body 112 of the housing 110. The horizontal cross-section of the grinding table 120 is circular. The grinding table 120 is, for example, disc-shaped. The grinding table 120 is installed within the housing 110 such that its axis of rotation is vertical. The grinding table 120 is rotated by a table drive motor 124 via a reduction gear 122. The grinding table 120 is rotated by the table drive motor 124 at a constant speed or variable speed.

[0023] A groove 126 is formed on the upper surface of the grinding table 120. The groove 126 is an annular groove centered on the rotation axis of the grinding table 120. The vertical cross-section of the groove 126 passing through the rotation axis of the grinding table 120 is arc-shaped.

[0024] The roller unit 130 is provided within the housing 110. One or more roller units 130 are provided. For example, three roller units 130 are provided. The roller unit 130 includes a crushing roller 132, a roller shaft 134, a bracket 136, and a pivot shaft 138. The crushing roller 132 is rotatably mounted above the crushing table 120 within the main body 112 of the housing 110. The crushing roller 132 is positioned, for example, at an inclination above the groove 126 of the crushing table 120. The more material to be crushed guided into the groove 126, the smaller the inclination of the crushing roller 132 becomes (closer to horizontal), and the less material to be crushed guided into the groove 126, the larger the inclination of the crushing roller 132 becomes. The crushing roller 132 rotates in accordance with the rotation of the crushing table 120. To explain in more detail, the rotation of the grinding table 120 causes the material to be ground on the grinding table 120 to rotate and move along with the grinding table 120. As the material to be ground moves, the frictional force generated between the material to be ground and the grinding roller 132 causes the grinding roller 132 to rotate.

[0025] In this embodiment, the three grinding rollers 132 are arranged radially at 120° intervals from the rotation center of the grinding table 120. The grinding rollers 132 are rotatably supported by bearings (not shown) attached to the roller shafts 134. The roller shafts 134 are inserted through a bracket 136. The bracket 136 is provided through an opening 116, extending from inside the cover 118 of the housing 110 to inside the main body 112. In addition to the roller shafts 134, a pivot shaft 138 is inserted through the bracket 136. The pivot shaft 138 is supported by bearings (not shown).

[0026] Each roller unit 130 is provided with one pressurizing device 140. In this embodiment, the vertical mill 100 has three roller units 130, so three pressurizing devices 140 are provided. The pressurizing devices 140 penetrate the cover 118 of the housing 110. The pressurizing devices 140 include an actuator, which is, for example, a hydraulic cylinder. The pressurizing devices 140 pressurize the grinding roller 132 toward the grinding table 120. In this embodiment, the pressurizing devices 140 press against the receiving seat 136a formed on the bracket 136. This applies a load to the receiving seat 136a. As a result, the bracket 136 swings about the pivot axis 138 as the center of rotation. The grinding roller 132 swings with the bracket 136 and is pressed toward the grinding table 120 below.

[0027] The supply pipe 150 is cylindrical. The supply pipe 150 is inserted through the upper wall 112c of the housing 110 such that its axial direction is vertical or substantially vertical. In this embodiment, the supply pipe 150 is inserted through the housing 110 so as to be coaxial with the housing 110. Also in this embodiment, the supply pipe 150 is inserted through the housing 110 so as to be coaxial with the rotation axis of the grinding table 120. The upper opening of the supply pipe 150 is located outside the housing 110. The lower opening of the supply pipe 150 faces the grinding table 120 which is provided inside the housing 110. A material to be ground supply device (not shown) is connected to the upper opening of the supply pipe 150. The material to be ground is supplied onto the grinding table 120 through the supply pipe 150 by the material to be ground supply device.

[0028] The material to be crushed is, for example, solid fuel such as coal and biomass pellets. The biomass is, for example, one or more of the following: woody biomass, herbaceous biomass, and waste biomass. Woody biomass includes, for example, wood, sawdust, and bark. Herbaceous biomass includes, for example, sugarcane, sorghum, bamboo, wheat straw, and rice straw. Waste biomass includes, for example, empty fruit bunches (EFB) and palm kernel shells (PKS) resulting from palm oil production from palm trees.

[0029] The discharge port 160 is formed above the crushing roller 132 in the housing 110. The discharge port 160 is formed, for example, in the upper wall 112c of the housing 110. Therefore, the distribution section 114 is provided between the crushing roller 132 and the discharge port 160. In this embodiment, the vertical mill 100 has a plurality of discharge ports 160. The plurality of discharge ports 160 are formed in the upper wall 112c of the housing 110 at approximately equal intervals along the circumferential direction of the housing 110. Discharge pipes 162 are connected to the discharge ports 160. The discharge pipes 162 discharge the material crushed by the crushing table 120 and the crushing roller 132 to the outside. For example, the combustion port of a furnace constituting a power generation device is connected to the discharge pipes 162.

[0030] The outlet 170 is provided on or outside the outer edge of the grinding table 120. In this embodiment, the vertical mill 100 is provided with a plurality of outlets 170. The plurality of outlets 170 are provided outside the outer edge of the grinding table 120 and are formed at approximately equal intervals along the outer edge of the grinding table 120.

[0031] The airflow forming unit 180 forms an airflow within the housing 110, moving from the outlet 170 towards the discharge port 160. That is, the airflow forming unit 180 forms an upward airflow within the housing 110. The airflow forming unit 180 includes, for example, a blower that supplies gas to the outlet 170. The gas supplied by the airflow forming unit 180 may be, for example, air, combustion exhaust gas, or nitrogen. The configuration of the airflow forming unit 180 is not limited as long as it can form an airflow within the housing 110, moving from the outlet 170 towards the discharge port 160. The airflow forming unit 180 may, for example, include a blower that sucks gas from the discharge port 160, in addition to, the blower that supplies gas to the outlet 170.

[0032] In this embodiment, the vertical mill 100 may also include a rotary classifier 190. The rotary classifier 190 is provided within the main body portion 112 of the housing 110. The rotary classifier 190 includes, for example, a rotary rotor 192 and a plurality of blades 194. The rotary rotor 192 is an annular member provided so as to surround the outer circumference of the supply pipe 150. The plurality of blades 194 are provided at approximately equal intervals in the circumferential direction of the rotary rotor 192. The rotary rotor 192 is rotated by a drive device (not shown). The rotation of the rotary rotor 192 rotates the plurality of blades 194. In this embodiment, the rotation of the rotary rotor 192 may be stopped, although this will be described in more detail later. Also, the plurality of blades 194 may be removed.

[0033] The covering plate 200 is provided on the main body portion 112 side of the housing 110, beyond the cover 118. The covering plate 200 covers at least a portion of the opening 116 of the housing 110.

[0034] In this embodiment, the vertical mill 100 may also include one or both of the accumulation prevention plate 210 and the filler material 220. The accumulation prevention plate 210 is provided inside the cover 118 of the housing 110. The filler material 220 is filled into the space formed between the cover 118 and the covering plate 200.

[0035] Details of the covering plate 200, the accumulation prevention plate 210, and the filler material 220 will be described later.

[0036] [2. Operation of the vertical mill] Next, with reference to Figure 1, the operation of the vertical mill 100 according to this embodiment will be described. First, the material to be crushed is supplied onto the crushing table 120 through the supply pipe 150 by the material to be crushed supply device.

[0037] The material to be crushed, supplied to the crushing table 120, is caught between the grooves 126 of the crushing table 120 and the crushing rollers 132. As the crushing table 120 rotates, the caught material is crushed and crushed by the crushing rollers 132.

[0038] The pulverized material then rises through the main body 112 of the housing 110 along with the gas blown out through the outlet 170 by the airflow forming unit 180. In other words, the pulverized material rises through the main body 112 of the housing 110 in a solid-gas two-phase flow state. The pulverized material then passes through the rotary classifier 190 and is airflow-conveyed to the distribution unit 114 of the housing 110.

[0039] As described above, the inner diameter of the distribution section 114 gradually increases from bottom to top. Therefore, the flow velocity of the solid-gas two-phase flow conveyed to the distribution section 114 gradually decreases from bottom to top. This allows for the formation of a vortex flow within the distribution section 114. The material to be pulverized is then efficiently dispersed by the vortex flow within the distribution section 114. Consequently, the material to be pulverized is distributed almost uniformly to the multiple discharge ports 160. The material distributed to the multiple discharge ports 160 is then discharged to the outside through the discharge pipe 162.

[0040] [3. Covering plate] Next, the details of the covering plate 200 according to this embodiment will be described with reference to Figures 2 and 3. Figure 2 is a partially enlarged view of Figure 1. Figure 3 is a front view of the covering plate 200 according to this embodiment. Note that in Figure 2, the fixing member 202 is omitted for ease of understanding. Also, in Figure 3, the cross-section of the bracket 136 and the cross-section of the pressurizing device 140 in the YZ plane, which includes the surface of the covering plate 200 that faces inward into the housing 110, are shown by dashed lines. In Figure 3, the opening 116 is shown by a dashed line.

[0041] As described above, the cover 118 of the housing 110 protrudes outward from the main body 112 (in the -X direction in Figure 2) in order to secure space to accommodate part of the roller unit 130 and part of the pressurizing device 140. For this reason, the cross-sectional area of ​​the airflow path (flow path cross-sectional area) in the part of the housing 110 where the cover 118 is provided is larger than the airflow path formed inside the main body 112. Consequently, the velocity of the rising airflow decreases in the part of the housing 110 where the cover 118 is provided.

[0042] When coal is supplied to a furnace that constitutes a power generation device, the target particle size of the coal required in the furnace is, for example, about 40 μm. Therefore, in a vertical mill designed for coal crushing, the velocity of the rising airflow in the main body 112 of the housing 110, the velocity of the rising airflow in the part of the housing 110 where the cover 118 is provided, and the rotational speed of the rotary classifier are determined so that particles with a particle size of about 40 μm are discharged from the outlet.

[0043] On the other hand, when biomass is supplied to a furnace that constitutes a power generation device, the target particle size of the biomass required in the furnace is, for example, 500 μm or more and 700 μm or less. In other words, the target particle size of the biomass in the furnace is larger than the target particle size of coal, for example, 15 times or more the target particle size of coal. Therefore, when biomass is crushed using a vertical mill designed for crushing coal, even if the biomass is crushed to the target particle size, it accumulates in the part of the housing 110 where the cover 118 is provided, making it difficult to transport it to the discharge port by airflow. In short, when biomass is crushed using a vertical mill designed for crushing coal, if the biomass is not crushed excessively to the target particle size of coal, it becomes difficult to transport it to the discharge port by airflow.

[0044] Therefore, the vertical mill 100 according to this embodiment is equipped with a covering plate 200. As shown in Figures 2 and 3, the covering plate 200 is provided inside the cover 118 of the housing 110. In this embodiment, the covering plate 200 covers at least the upper part of the opening 116 of the housing 110. The upper part is, for example, a range from the upper end of the opening 116 of the housing 110 to 50% of the vertical length of the opening 116 (the -Z direction in Figures 2 and 3), preferably up to 70%, more preferably up to 80%, and even more preferably up to 90%. Note that the covering plate 200 is not limited to the area it covers as long as it can cover at least a part of the opening 116 of the housing 110. For example, the covering plate 200 may cover the lower part of the opening 116 of the housing 110. Alternatively, for example, the covering plate 200 may cover the entire opening 116 of the housing 110. For example, the covering plate 200 may cover the side of the opening 116 of the housing 110 (the end in the Y direction in Figure 2).

[0045] As shown in Figure 3, the covering plate 200 is fixed to the cover 118 of the housing 110 by fixing members 202. The fixing members 202 include, for example, L-shaped angles (angle steel) and bolts.

[0046] The surface of the covering plate 200 facing inward into the housing 110 (the surface positioned in the +X direction in Figure 2) is, for example, flush with the inner circumferential surface of the main body portion 112 of the housing 110. However, the surface of the covering plate 200 facing inward into the housing 110 may be positioned outward (towards the cover 118) from the inner circumferential surface of the main body portion 112 of the housing 110.

[0047] The covering plate 200 is fixed to the cover 118 of the housing 110, for example, along the vertical direction (Z direction in Figure 2) or approximately vertical direction.

[0048] Furthermore, as shown in Figures 2 and 3, in this embodiment, it is preferable that the covering plate 200 has a first opening 204 and a second opening 206.

[0049] A pressurizing device 140 is fitted into the first opening 204. For example, if the pressurizing device 140 has two hydraulic cylinders, two first openings 204 are formed in the covering plate 200. A bracket 136 of the roller unit 130 is fitted into the second opening 206.

[0050] One or both of the first opening 204 and the second opening 206 are holes or notches. In this embodiment, the first opening 204 and the second opening 206 are notches that communicate with each other. This improves the workability when forming the first opening 204 and the second opening 206 in the covering plate 200.

[0051] [4. Deposition prevention plate] Next, the details of the accumulation prevention plate 210 according to this embodiment will be described with reference to Figures 2 to 4. Figure 4 is a front view of the accumulation prevention plate 210 according to this embodiment. In Figure 4, the cross-section of the bracket 136 in the YZ plane, which includes the surface of the covering plate 200 that faces inward into the housing 110, is shown by a dashed line. In Figure 4, the opening 116 is shown by a dashed line.

[0052] The deposit prevention plate 210 is provided inside the cover 118 of the housing 110. In this embodiment, the deposit prevention plate 210 covers at least the lower part of the opening 116 of the housing 110. The deposit prevention plate 210 is provided below the pressurizing device 140 inside the cover 118. The deposit prevention plate 210 is inclined downward as it moves from the cover 118 toward the main body 112.

[0053] Furthermore, as shown in Figure 4, a third opening 212 is formed in the accumulation prevention plate 210. The bracket of the roller unit 130 is fitted into the third opening 212. The third opening 212 is a hole or a notch.

[0054] Furthermore, the lower end of the accumulation prevention plate 210 is positioned outward from the air outlet 170. The lower end of the accumulation prevention plate 210 may be in contact with the lower end of the covering plate 200. Additionally, a gap may be formed between the lower end of the accumulation prevention plate 210 and the lower end of the covering plate 200, such that the filler material 220, which will be described later, does not fall through.

[0055] The vertical mill 100 according to this embodiment is equipped with an accumulation prevention plate 210, which, together with the filler material 220 described later, can suppress the intrusion of material to be crushed into the cover 118 side through the gap formed below the covering plate 200. Furthermore, the vertical mill 100 according to this embodiment is equipped with an accumulation prevention plate 210, which can prevent the filler material 220 from falling.

[0056] [5. Filler] Next, with reference to Figure 2, the filler material 220 according to this embodiment will be described.

[0057] The filler material 220 is filled, for example, into the space formed between the cover 118 of the housing 110 and the covering plate 200. In this embodiment, the filler material 220 is filled into the space formed between the covering plate 200 and the deposit prevention plate 210 within the cover 118 of the housing 110.

[0058] The filler material 220 is made of a material that is flexible and heat-resistant. Here, flexibility refers to the property of being able to follow the movement of the bracket 136 of the roller unit 130. In this embodiment, flexibility is synonymous with at least one of deformability, resilience, and pliability. Heat resistance refers to the property of being able to maintain flexibility when exposed to temperatures of approximately 100°C. The filler material 220 is, for example, fibrous glass (glass wool), fibrous heat-resistant resin, or a sponge made of heat-resistant resin.

[0059] [6. Summary] As described above, the vertical mill 100 according to this embodiment includes a housing 110 which includes a cylindrical main body portion 112, an opening 116 formed on the side surface 112b of the main body portion 112, and a cover 118 which closes the opening 116 and protrudes outward from the main body portion 112, a grinding table 120 provided inside the main body portion 112 of the housing 110, a grinding roller 132 which is rotatably provided above the grinding table 120 inside the main body portion 112 of the housing 110, and a roller shaft which rotatably supports the grinding roller 132. The roller unit 130 is provided inside the housing 110 and includes a 134 and a bracket 136 through which the roller shaft 134 is inserted, with a portion of the bracket provided inside the cover 118 of the housing 110; a pressurizing device 140 that penetrates the cover 118 of the housing 110 and presses the bracket 136 of the roller unit 130 toward the crushing table 120; and a covering plate 200 provided on the main body 112 side of the cover 118 of the housing 110 and covering at least a portion of the opening 116 of the housing 110.

[0060] The vertical mill 100 according to this embodiment, by being equipped with a covering plate 200, can reduce the flow path cross-sectional area of ​​the airflow path in the portion of the housing 110 where the cover 118 is provided, compared to a conventional vertical mill without a covering plate 200. Therefore, in the vertical mill 100 according to this embodiment, the velocity of the rising airflow increases in the portion of the housing 110 where the cover 118 is provided. As a result, when crushing biomass pellets, the vertical mill 100 according to this embodiment can suitably convey the biomass, which has been crushed to the target particle size, from the crushing table 120 to the discharge port. Therefore, the vertical mill 100 according to this embodiment can increase the amount of biomass discharged per unit time compared to when crushing biomass pellets with a conventional vertical mill without a covering plate 200. Furthermore, the vertical mill 100 according to this embodiment can increase the amount of material discharged per unit time compared to a conventional vertical mill without a covering plate 200, regardless of the type of material to be ground.

[0061] Furthermore, the vertical mill 100 according to this embodiment can prevent the rising airflow from flowing toward the cover 118 side by the covering plate 200. In other words, the vertical mill 100 according to this embodiment can guide the rising airflow toward the central side of the housing 110, for example, toward the rotary classifier 190 by the covering plate 200. As a result, the vertical mill 100 according to this embodiment can further increase the amount of material to be crushed per unit time.

[0062] Furthermore, the vertical mill 100 according to this embodiment can improve the velocity of the updraft simply by attaching the covering plate 200 to a conventional vertical mill. Therefore, the vertical mill 100 according to this embodiment can increase the amount of biomass emitted per unit time with simple modifications.

[0063] Furthermore, the vertical mill 100 according to this embodiment may also include a filler material 220 that is flexible and heat-resistant and fills the space formed between the cover 118 and the covering plate 200.

[0064] As a result, the vertical mill 100 according to this embodiment can prevent the material to be crushed from entering the cover 118 side from the portion of the opening 116 that is not covered by the covering plate 200. Therefore, the vertical mill 100 according to this embodiment can prevent malfunctions of the roller unit 130 and the pressurizing device 140 that may occur due to the material to be crushed.

[0065] Furthermore, the covering plate 200 may have a first opening 204 into which the pressurizing device 140 is fitted.

[0066] As a result, in the vertical mill 100 according to this embodiment, the area around the pressurizing device 140 can be sealed with a covering plate 200, further preventing the intrusion of the material to be crushed into the cover 118 side.

[0067] Furthermore, the covering plate 200 may have a second opening 206 into which the bracket 136 of the roller unit 130 is fitted.

[0068] As a result, in the vertical mill 100 according to this embodiment, the area around the bracket 136 of the roller unit 130 can be sealed with the covering plate 200, further preventing the intrusion of the material to be crushed into the cover 118 side.

[0069] Furthermore, the covering plate 200 may cover at least the upper part of the opening 116 of the housing 110.

[0070] As a result, the vertical mill 100 according to this embodiment can further increase the amount of material to be ground per unit time.

[0071] While embodiments have been described above with reference to the attached drawings, it goes without saying that this disclosure is not limited to the embodiments described above. It will be obvious to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of this disclosure.

[0072] This disclosure can contribute, for example, to Sustainable Development Goal (SDG) 7, "Ensure access to affordable, reliable, sustainable and modern energy," and Goal 13, "Take urgent action to combat climate change and its impacts." [Explanation of symbols]

[0073] 100: Vertical mill 110: Housing 112: Main body 112b: Side view 116: Opening 118: Cover 120: Grinding table 130: Roller unit 132: Grinding roller 134: Roller shaft 136: Bracket 140: Pressurizing device 200: Covering plate 204: First opening 206: Second opening 220: Filling material

Claims

1. A housing comprising a cylindrical main body, an opening formed on the side of the main body, and a cover that closes the opening and protrudes outward from the main body, A crushing table provided within the main body of the housing, A roller unit provided within the housing includes: a grinding roller rotatably mounted above the grinding table within the main body of the housing; a roller shaft that rotatably supports the grinding roller; and a bracket through which the roller shaft is inserted, with a portion of it provided within the cover of the housing. A pressurizing device that penetrates the cover of the housing and presses the bracket of the roller unit toward the crushing table, An airflow forming unit that forms an airflow from the outer edge of the grinding table or an outlet provided outside the outer edge toward an outlet formed above the grinding roller in the housing, A covering plate is provided on the main body side of the housing, which is closer to the main body than the cover of the housing, and covers at least a part of the opening of the housing. Equipped with, The covering plate covers a range from the upper end of the opening of the housing to 50% or more of the vertical length of the opening, in a vertical mill.

2. The vertical mill according to claim 1, wherein the covering plate is fixed to the cover of the housing.

3. The vertical mill according to claim 1 or 2, wherein the covering plate is provided inside the cover of the housing.

4. The vertical mill according to claim 1 or 2, wherein the surface of the covering plate facing inward from the housing is flush with the inner circumferential surface of the main body of the housing, or is positioned on the cover side of the inner circumferential surface of the main body of the housing.

5. The vertical mill according to claim 1 or 2, comprising a filler material that is flexible and heat-resistant and fills the space formed between the cover and the covering plate.

6. The vertical mill according to claim 1 or 2, wherein the covering plate has a first opening into which the pressurizing device is fitted.

7. The vertical mill according to claim 1 or 2, wherein the covering plate has a second opening into which the bracket of the roller unit is fitted.

8. The vertical mill according to claim 1 or 2, wherein the covering plate covers at least the upper part of the opening of the housing.

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