KR20050009212A - Vertical mill and method for determining the shape of a crushing face - Google Patents

Abstract

PURPOSE: A vertical mill and a method for determining the shape of a crushing face are provided to guarantee high crushing efficiency and prevent the congestion of material. CONSTITUTION: The height(H1) of an outside portion(22) of a table-opposed face(21) is determined to be a value by which material at an intersecting point(P) rises above the outside portion(22) by a centrifugal force to be cut and discharged. If this value is satisfied, the shape of a crushing face is determined in a manner that the radiuses(Rr1,Rout1,Rin1) of a roller outer peripheral face(20) and the table-opposed face(21) becomes larger in the above order, and an inner gap( in1) becomes smaller and an outer gap( out1) becomes constant as they go outward.

Description

Vertical mill and its grinding surface shaping method {VERTICAL MILL AND METHOD FOR DETERMINING THE SHAPE OF A CRUSHING FACE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical mill for pulverizing raw materials with a table liner and a grinding roller, and more particularly to a method for determining the shape of the grinding surface.

Vertical mills have a grinding roller on top of the table liner, and the raw material supplied onto the table liner is compressed by the table liner and grinding roller by rotating the table liner around the vertical axis so as to be displaced radially outward. It is to be ground by grinding. When the blast furnace chain slug supplied as a raw material to the vertical mill is pulverized, the iron particles contained in the blast furnace chain slug stay on the table liner and wear the grinding roller and the table liner.

The situation where the iron powder stays on the tableliner becomes remarkable as the vertical mill becomes larger. This phenomenon occurs because the size of the vertical mill is designed to change approximately similarly. Specifically, when the vertical mill becomes large, the height from the reference point on the table liner to the outer edge of the table increases, but the centrifugal force applied to the table liner as the raw material on the reference point is constant during the grinding operation. This is because it is difficult to rise on the table liner because the iron particles are rotated at the rotational speed.

In order for the iron powder to easily climb on the table liner, it is conceivable to increase the rotational speed so that the centrifugal force applied to the raw material increases as the vertical mill becomes larger. In this case, however, the situation where the raw material is sandwiched between the table liner and the grinding roller is worsened and the vibration is increased, thereby impairing the stable operation and lowering the grinding efficiency. Therefore, in order to prevent the retention of the iron powder, it is not possible to increase the rotational speed of the table liner. Therefore, a technique capable of preventing the retention of the iron powder in other configurations is desired.

In order to prevent the iron particles from remaining on the table liner, vertical mills are known in which chutes are provided to reduce the flow rate of the gas blown out around the table liner. In this vertical mill, a chute is installed at a portion of the gas jetted at a gas ejection outlet provided around the table liner to reduce the flow rate of the gas in a part of the circumferential direction. It is configured to recover the iron powder. Therefore, the iron particles which have climbed up the table liner are prevented from being blown up by the ejected gas and returned to the table liner, so that it can be prevented from staying on the table liner (Japanese Utility Model Registration No. 2502099). Reference).

However, in the vertical mill disclosed in Japanese Utility Model Registration No. 2502099 described above, iron particles having risen from the table liner by centrifugal force due to the rotation of the table liner are recovered by using the chute and returned to the table liner. However, iron particles which failed to climb the table liner remain on the table liner. That is, if the iron particles do not reach the table liner, even if the technique described in the Japanese Utility Model Registration No. 2502099 is adopted, it is impossible to prevent the iron particles from staying. Therefore, in the vertical mill similarly described above, even if the technique described in Japanese Utility Model Registration No. 2502099 is adopted, the iron particles do not climb the table liner, so that the iron particles cannot be prevented from staying. do.

Accordingly, it is an object of the present invention to provide a vertical mill and a method for determining the shape of the grinding surface thereof, which can ensure high grinding efficiency and prevent the retention of raw materials.

1 is a cross-sectional view showing a vertical mill according to an embodiment of the present invention,

2 is a cross-sectional view taken along the line II-II of FIG.

3A and 3B are cross-sectional views showing examples of the grinding surface shape of the vertical mill according to the present invention, and FIG. 3A shows the grinding surface shape of the relatively small vertical mill, and FIG. 3B shows the grinding surface shape of the relatively large vertical mill. ,

4 is a flow chart showing a grinding surface shape determination method;

5A and 5B are vertical mills for crushing blast furnace chain slugs showing sectional examples of vertical mills according to the present invention, FIG. 5A shows a small vertical mill with a throughput of 50 t / h, and FIG. 5B Denotes a large vertical mill with a throughput of 110 t / h.

The present invention for achieving the above object is, on the top of the table liner provided so as to be able to rotate around the axis of the table arranged in a substantially vertical direction, around the axis of the roller inclined downward toward the table radially inward. In the grinding surface shaping method of the vertical mill, in which the grinding roller provided to be rotatable is elastically pressed toward the table liner and configured to grind the raw material between the table liner and the grinding roller, the grinding surface is a grinding roller. The outer peripheral surface of the roller outer peripheral surface and the surface of the table facing the outer surface of the table liner and the table facing surface, and in the virtual plane including the roller axis and the axis of the table, disposed between both sides of the roller axis direction of the grinding roller Set a reference axis arranged perpendicular to the roller axis, and within the virtual plane, the table The opposing surface is divided into an outer portion from the intersection with the reference axis to the outer radial end of the table and an inner portion from the intersection to the inner radial end of the table so that the outer peripheral surface of the roller and the outer portion of the facing surface of the table are separated. A circular arc centered on a first center point on the reference axis, and an inner portion of the table opposing face is centered on a second center point on the reference axis which is radially inward of the table above the first center point. And the vertical dimension of the outer portion corresponding to the radially outer end of the table from the intersection with the reference axis of the table facing surface in the virtual plane, when the tableliner is rotated. Raw material disposed on the table from the table opposing surface using centrifugal force imparted by the rotation. Determine the dimensions to discharge radially outwardly of the table, and make sure that the vertical dimension of the outer portion of the table opposing face satisfies the condition to be the determined dimension, and then While the radius increases, the radius of the inner side of the table facing surface becomes larger than the radius of the outer surface of the table facing surface, and the distance between the outer peripheral surface of the roller and the inner portion of the table facing surface decreases gradually toward the outside of the table, It is characterized in that the radius of the outer circumferential surface and the outer and inner portions of the table circumferential surface and the table opposing surface is determined so that the distance between the outer circumferential surface of the roller and the outer surface of the table opposing surface becomes constant.

According to the present invention as described above, the vertical dimension of the outer portion of the table opposing face can be determined as the size at which the raw material rises up the table opposing face with centrifugal force and is discharged.

After this dimension is satisfied, the radius of the roller outer circumferential surface, the outer side of the table opposing face and the inner side of the table increases in order, and the gap between the outer circumferential surface of the roller and the inner side of the table opposing face toward the outer side becomes larger. On the other hand, the shape of the grinding surface is determined so that the distance between the roller outer circumferential surface and the outer side of the table facing surface becomes constant.

As such, the radius of the roller outer circumferential surface and the table opposing surface has the relationship as described above, and the clearance between the roller outer circumferential surface and the table opposing surface becomes the same shape as described above, whereby The grinding can be made stable. In other words, the better bite state of the raw material can be reliably applied to the bite of the raw material so that fine grinding can be achieved. In this way, high grinding efficiency can be obtained.

In order to maintain such a high crushing efficiency, the centrifugal force imparted to the raw material on the table liner should have high operating stability, that is, a centrifugal force capable of stably obtaining a good bite state of the raw material. Therefore, since it is necessary to operate so that such centrifugal force can be obtained at the time of operation, the vertical dimension of the outer part of the table opposing face is determined in consideration of such centrifugal force. As a result, even when operating at a centrifugal force capable of obtaining a high grinding efficiency as described above, the raw material is discharged to the table liner. In this way, a high grinding efficiency is obtained and the grinding surface shape which can prevent the raw material from remaining on the table liner can be determined.

In addition, the present invention is a vertical mill characterized by having a grinding surface of the shape determined by the vertical mill grinding surface shaping method described above, which has a high grinding efficiency because the grinding surface is determined by the method described above. In addition to this, it is possible to prevent the raw material from remaining on the table liner. In this way, it is possible to obtain a vertical mill in which the retention of raw materials is prevented.

As described above, according to the present invention, a high grinding efficiency can be obtained, and the shape of the grinding surface that can prevent the raw material from remaining on the table liner can be determined. In addition, when the raw material can be prevented from remaining, for example, the wear of the table liner and the grinding roller due to the components of the raw material such as iron powder contained in the raw material can be suppressed to increase durability. Therefore, a high grinding efficiency can be obtained and a durable vertical mill can be designed.

In addition, according to the present invention, high grinding efficiency can be obtained, and raw materials are prevented from remaining on the table liner, so that a durable vertical mill can be obtained. Therefore, it is possible to grind the raw material for a long time with high grinding efficiency.

(Example)

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a cross-sectional view showing a vertical mill according to an embodiment of the present invention, Figure 2 is a cross-sectional view seen from the cutting line II-II of FIG. The vertical mill, also referred to as a vertical roller mill, has a table 2 provided so as to rotate about an axis L2 (hereinafter referred to as a "table axis") of a table erected in a substantially vertical direction in the casing 1, and driving means. (3) can be rotated and driven. The table 2 is provided with a table liner 2a.

On the upper side of the table 2, a feed pipe 4 is provided coaxially with the table 2, and a raw material such as blast furnace slug slug containing iron powder as a to-be-ground object is supplied to the table 2, for example. ) Is supplied. This blast furnace slug usually contains about 0.3 to 0.5% of iron powder, and in many cases, about 1 to 2% of iron powder.

On the other hand, a plurality of grinding rollers 5 are provided in the circumferential direction above the table liner 2a in this embodiment, and each of these grinding rollers 5 is arranged between the table liner 2a. In the state where the raw material is elastically bitten, the arm 6 is supported by the arm 6 so as to be able to rotate around the axis L5 of the roller (hereinafter referred to as the "roller axis"). The roller axis L5 extends in the radial direction of the table 2 (hereinafter referred to as "table radial direction"), crosses the table axis L2, and is inclined downward while going inward in the table radial direction.

And each said arm 6 is provided so that it may angularly displace around the horizontal support shaft 7 perpendicular | vertical to roller axis line L5. Each of these arms 6 is pushed and pushed elastically so as to angularly displace around the support shaft 7 by the pressing means 8, whereby each roller 5 is a table liner ( It is elastically pushed toward 2a).

The raw material introduced from the feed pipe 4 is separated on the center position of the table 2, moved outwardly by the centrifugal force, and is bitten and crushed between the table liner 2a and the grinding roller 5. In this way, the raw materials are crushed to form granular materials.

A spout 9 is provided around the table liner 2a for spouting upward air. Thereby, the granular material formed by pulverizing the raw material is moved outwardly on the table liner 2a by the centrifugal force applied as the table 2 rotates, and then discharged outward on the table liner 2a. It is blown up by the air blown out from (9).

The upper part of the casing 1, that is, the upper part of the table 2, has a classifier 11 built in. The classifier 11 has a reverse conical cone installed coaxially with the supply pipe 4, cone 12, a classing blade 13 which rotates around the classifying axis L11 in the vertical direction in the cone 12, and a guide vane 15 for guiding fine powder that is pulverized and floated. It is supposed to have

The granules spouted by the air spouted from the spout 9 are introduced into the cone 12 from the inlet 14 via the guide vane 15 and classified by the classifier vane 13. That is, the granular material is classified into fine powder having a small particle diameter and granular material having a large particle diameter in the classifier 11. The fine powder is discharged through the discharge pipe 16 extending from the top of the cone 12, and the powder is dropped from the bottom of the cone 12 onto the table 2 and pulverized again.

3A and 3B are cross-sectional views showing one example of the shape of the grinding surface of the vertical mill according to the present invention. 3A and 3B show a cross section cut in an imaginary plane including the table axis L2 and the roller axis L5. 3A shows the grinding surface shape of a relatively small vertical mill, and FIG. 3B shows the grinding surface shape of a relatively large vertical mill. 4 is a flowchart showing a shape determination method of a crushed surface.

3A and 3B, subscripts "1" and "2" are added to variables (DT, DR, W, Win, Wout, Rr, Rin, Rout, H, δout, and deltain) representing dimensions for easy understanding. The addition was shown. In the following description, subscripts are specified when specifying each dimension, but subscripts are omitted when not specified.

In the vertical mill, as described above, the raw material is crushed by the table liner 2a and the grinding roller 5. A grinding surface for crushing the raw material having a roller outer peripheral surface 20 which is the outer peripheral surface of the grinding roller 5 and a table facing surface 21 which is the surface of the table liner 2a facing the roller outer peripheral surface 20 The shape of the crushed surface is determined in the order according to the shape determination method of the present invention. In this shape determination method, the shape in the virtual plane is also determined.

When the order of the crushed surface shaping is started in step s0, the reference axis LO is first set in the reference setting step of step s1. The reference axis line LO is disposed between both sides of the grinding roller 5, that is, both sides of the direction along the axis of the grinding roller 5 (hereinafter referred to as the "roller axis direction"), to the roller axis L5. It is an axis perpendicular to the axis. The reference axis line LO is divided into two parts of the dimension W in the roller axis direction of the grinding roller 5 so that one side and the other dimension Win, Wout in the roller axis direction are equal (Win = Wout). That's the centerline.

After the reference axis LO is set in this way, the process proceeds to the height determination process of step s2. In this height determination step, the table opposing surface 21 is formed from the outer portion 22, which extends from the intersection point P with the reference axis LO to the radially outer end of the table, and from the outer portion 22. FIG. The inner portion 23 extends from the intersection point P extending radially inward to the radially inner end of the table. Then, the height H, which is the vertical dimension of the outer portion 22, is determined.

The roller outer circumferential surface 20 and the table opposing surface 21 basically form an arc shape. The roller outer circumferential surface 20 forms an arc shape having a radius of curvature Rr about the first center point C1 disposed on the reference axis LO. In addition, the outer portion 22 has an arc shape having a radius of curvature Rout about the first center point Cl. On the other hand, the inner portion 23 is a radius of curvature (Rin) around the second center point (C2) disposed on the reference axis (LO) in the table radially inward and above the first center point (Cl). It is supposed to be arc shape with. In this height determination step, the height H of the outer portion 22 of the table liner 2a is determined among the arcuate grinding surfaces.

Vertical mills are generally designed similarly. That is, based on the throughput of the raw material to be treated per unit time, the dimensions of each configuration are designed to be approximately proportional to the throughput. Accordingly, the diameter of the circle (hereinafter referred to as "working diameter") including the intersection point P on the circumference centering on the axis L2 on the table, the maximum outer diameter DR of the grinding roller 5, The roller axial dimension W (hereinafter referred to as "roller width") of the grinding roller 5 and each of the radiuses of curvature Rr, Rin, and Rout of the grinding surface become larger as the throughput increases.

Specifically, the working diameter DT is determined based on the throughput, and the radius of curvature Rr of the roller outer circumferential surface 20 is the empirical value when the working diameter is the reference working diameter, for example, the working diameter DT1 of the small vertical mill. Based on the radius of curvature Rr1 determined based on i), a calculation is performed to multiply the ratio of the working diameter by a predetermined coefficient K1, and the radius of curvature at another throughput, for example, "Rr2", is expressed by Equation (1). ). In addition, the maximum diameter and the roller width of the grinding roller 5 are obtained by calculating the multiplication of the working diameter DT by the predetermined coefficients K2 and K3, as shown in equations (2) and (3).

Rr2 = (DT2 / DT1) × Rr1 × K1

DR = K2 × DT

W = K3 × DT

Since the dimensions are proportionally determined in this manner, the dimensions Win and Wout of both the reference axes LO of the grinding roller 5 also increase with the throughput. That is, DTl <DT2, DR1 <DR2, W1 <W2, Rr1 <Rr2, Rin1 <Rin2, Rout1 <Rout2, Win1 <Win2, Wout1 <Wout2.

However, it is not possible to design completely similarly so that all dimensions become larger as the throughput increases. Since the raw material itself does not change even if the throughput is large, the gap between the outer peripheral surface Rr and the outer part Rout (δout; hereinafter referred to as 'outer gap') in order to satisfactorily grind the raw material with high grinding efficiency. Is constant (δoutl = δout2) regardless of throughput.

In addition, as described in connection with the prior art, it is important to set the centrifugal force acting on the raw material on the intersection point P so that the raw material stably bites to obtain high grinding efficiency, so that a suitable centrifugal force can be obtained. The rotational speed of the table (2) should be determined so that it can This rotational speed must process the same raw material, and since the outer gap δout is also constant, the centrifugal force at the intersection P is determined to be constant.

In this way, in the vertical mill, the centrifugal force at the intersection point P is operated to be constant regardless of the processing amount. Thus, the raw material moving on the outer portion 22 by using the centrifugal force is the outer portion ( 22) The distance to climb (hereinafter referred to as the "distance") becomes constant. If the raw material cannot reach the outer portion 22, the raw material will stay on the table liner 2a. Therefore, the height H of the outer portion 22 should be smaller than the equivalent distance. Should be. In addition, since this equidistant distance changes with specific gravity of the component contained in a raw material, the equidistant distance becomes small, so that the containing component with a specific gravity is large. Therefore, the height H of the outer part 22 is determined to be smaller than the equivalent distance of the containing component with the largest specific gravity among raw materials.

For example, in blast furnace chain slugs, the specific gravity of iron powder is the largest, about 7.9, and the remaining components are about 1.0. In the case of crushing the blast furnace chain slug, the height H of the outer portion 22 is determined to be smaller than the equivalent distance of the iron powder particles.

Thus, in the height determination process, the height H of the outer part 22 is a raw material arrange | positioned at the said intersection point P when the table liner 2a is rotated, ie, when the table 2 is rotated, specifically, In the dimension, the largest specific component among the components of the raw material can be discharged radially outward from the table opposing surface 21 using the centrifugal force outwardly from the table radially given by the rotation. Will be decided. As described above, since the constant distance is constant regardless of throughput, the height H of the outer portion 22 is also constant regardless of throughput. That is, when the equidistant distance of the largest specific content component is HO, the following equation (4) is established.

HO> H = constant (H1 = H2)

After determining the height of the outer portion 22 in this manner, the process proceeds to the curvature radius determination process of step s3. In this curvature radius determining step, after the height H of the outer portion 22 satisfies the above-mentioned condition, that is, the expression (4), each curvature radius ( Rr, Rout, and Rin).

The first condition is a condition relating to a relationship between curvature radii of the crushed surfaces. Specifically, the radius of curvature Rout of the outer portion 22 is larger than the radius of curvature Rr of the roller outer circumferential surface 20, and the radius of the inner portion 23 is larger than the radius Rout of the outer portion 23. (Rin) is made large. That is, the following equation (5) is satisfied.

Rr <Rout <Rin

The second condition is a condition relating to a gap δin (hereinafter referred to as an “inner gap”) and an outer gap δout between the roller outer circumferential surface 20 and the inner portion 23. Specifically, the inner gap [delta] in becomes smaller toward the outside of the table radially, while the outer gap [delta] out is constant, i.e., uniformly equal in the table radial direction.

After the basic conditions satisfying Equation (4) are satisfied, each radius of curvature Rr, Rin, and Rout is determined to satisfy these two conditions. Then, the flow advances to step s4 to terminate the grinding surface shaping procedure.

5A and 5B are cross-sectional views for illustrating examples of the dimensions of the vertical mill according to the present invention. 5A and 5B are vertical mills for crushing blast-furnace slugs, the small vertical mills of which the throughput of FIG. 5A is 50 t / h (hereinafter referred to as the "small mill"), and the throughput of FIG. 5B. A large vertical mill (hereinafter referred to as `` large mill '') of 110 t / h is shown as an example. 5A and 5B, the same as in the case of FIGS. 3A and 3B, the subscripts '1' and '2' are added to the variables. Here, only the important dimensions representing the features of the present invention will be shown.

In the small mill, the working diameter DT1 is Φ2,600mm, the maximum outer diameter DRl of the roller is Φ2,000mm, and the roller width W1 is 700mm. The working diameter DT2 is Φ3,400mm and the maximum of the roller is The outer diameter DR2 is Φ2,615 mm, and the roller width W2 is 915 mm. In the small mill, the radius of curvature Rr1, Rout2, and Rin1 is 620 mm, 635 mm, and 725 mm, whereas in the large mill, the radius of curvature Rr2, Rout2, Rin2 is 810 mm, 825 mm, and 1,235 mm.

As such, the dimensions become larger with increasing throughput, but each outer gap δout1 and δout2 are all 15 mm, and the heights H1 and H2 are all 210 mm, so that they are the same in both small and large mills. It is. If it is designed similarly without considering centrifugal force as in the prior art, if the height of the small mill is 210 mm, the height Hpr is 275 mm in the large mill. In these dimensions, the retention of the raw material occurs, but the design of the present invention makes it possible to prevent the retention of the raw material.

According to the vertical mill according to the present embodiment as described above, the height H of the outer portion 22 of the table opposing surface 21 is such that the raw material rises up the table opposing surface 21 by centrifugal force and is discharged. Will be determined. Then, after satisfying this dimension, the curvature radii Rr, Rout, and Rin of the outer portion 22 and the inner portion 23 of the roller outer peripheral surface 20 and the table opposing surface 21 become larger in order. In addition, the shape of the grinding surface is determined such that the inner gap δin becomes smaller toward the outside while the outer gap δout is constant.

Each of the radiuses of curvature Rr, Rout, and Rin of the roller outer circumferential surface 20 and the table opposing surface 21 has the above-described relationship, and each gap δout and δin has a shape formed as described above. As a result, the grinding of the raw material that is held between the table liner 2a and the grinding roller 5 can be stably performed. In other words, the raw material is better to be bitten, and it is possible to reliably apply a suitable constant pressure to the raw material to be passed in, so that fine grinding can be achieved. In this way, loss of energy is suppressed and high grinding efficiency can be obtained.

On the other hand, in order to maintain such a high grinding efficiency, the centrifugal force imparted to the raw material on the table liner 2a should be such that the centrifugal force that can stably obtain high operating stability, that is, good bite of the raw material, can be obtained. . Therefore, since it should be operated so that such centrifugal force can be obtained at the time of operation, the height H of the outer part 22 of the table opposing surface 21 is determined in consideration of the centrifugal force. As a result, even when operating with a centrifugal force that can obtain a high grinding efficiency as described above, the raw material is discharged to rise on the table liner (2a). In this way, a high grinding efficiency can be obtained, while the shape of the grinding surface that can prevent the raw material from remaining on the table liner can be determined.

Although a detailed description is omitted, a chute such as that described in Japanese Utility Model Registration No. 2502099 described in connection with the prior art is provided for the component having a large specific gravity among the granular materials which are raised to the table liner 2a and discharged outward. You may make it collect | recover by methods, such as the following. Regardless of the method adopted, it is possible to prevent all components contained in the raw material from remaining on the table liner 2a. Thus, for example, in the case of a raw material containing iron powder such as blast furnace chain slug, it can be prevented from staying on the table liner 2a including the iron powder.

When raw materials, especially iron particles, stay on the table liner 2a, the wear of the table liner 2a and the grinding roller 5 proceeds violently, but wear can be prevented as shown in the present invention. By suppressing the durability can be increased. Since the durability can be increased in this way, high grinding efficiency can be obtained, and a vertical mill with high durability can be realized, and raw materials can be crushed for a long time with high grinding efficiency.

The above-described embodiments are merely illustrative of the present invention, and of course, the configuration may be changed in various ways within the scope of the present invention. That is, needless to say, the numerical values exemplified above are merely examples, and for example, an overhang for adjusting the behavior of the raw materials raised to the table liner 2a radially outward of the table liner 2a. A section 50 may be provided.

In addition, the table opposing surface 21 and its surface extending inward in the radial direction of the table liner 2a may be shaped to face upward as radially inward as shown in FIG. 5A, but FIG. 3A And may be horizontal as shown in FIGS. 3B and 5B.

When it is leveled in this way, it can suppress that a raw material moves to a perpendicular direction, and it becomes possible to operate more stably.

On the other hand, the raw material is not limited to the blast furnace chain slug, and may be, for example, a cement raw material or a cement clinker.

As described above, according to the present invention, a high grinding efficiency can be obtained, and the shape of the grinding surface which can prevent the raw material from remaining on the table liner can be determined. In addition, if the raw material can be prevented from remaining, wear of the table liner and the grinding roller by the components of the raw material such as iron powder contained in the raw material can be suppressed, thereby increasing durability. Therefore, while high grinding efficiency can be obtained, it is possible to prevent the material from remaining on the table liner and to obtain a vertical mill with high durability. As a result, the raw materials can be crushed over a long period of time with high grinding efficiency.

Claims (2)

On the top of the table liner installed so as to be able to rotate around the table axis which is arranged in a substantially vertical direction, a grinding roller installed so as to rotate around the roller axis which is inclined downward inwardly of the table radially is directed toward the table liner. In the crushing surface shaping method of the vertical mill is installed in a pressing state, crushing the raw material between the table liner and the grinding roller, The grinding surface has a roller outer peripheral surface, which is the outer peripheral surface of the grinding roller, and a table opposing surface, which is the surface of the table facing the roller outer peripheral surface, Set a reference axis perpendicular to the roller axis disposed between both sides of the roller axis direction of the grinding roller in an imaginary plane including the roller axis and the table axis, Within the imaginary plane, the table facing surface is divided into an outer portion from the intersection with the reference axis to the table radially outer end and an inner portion from the intersection to the table radially inner end, and the roller outer peripheral surface and the table facing The outer part of the surface to be arc-enhanced about the first center point on the reference axis, and the inner part of the table facing surface above the first center point and radially inward of the table, To make an arc shape centering on 2 center points, Within the imaginary plane, the vertical dimension of the outer portion from the intersection with the reference axis of the table opposing surface to the outer edge of the table radially extends the raw material disposed at the intersection when the table liner is rotated. Using the centrifugal force imparted by to determine the dimension discharged radially outward from the table opposing face, After satisfying the condition that the vertical dimension of the outer portion of the table opposing face becomes the determined dimension, the radius of the outer surface of the table opposing face becomes larger than the radius of the outer peripheral surface of the roller and the table opposes the radius of the outer portion of the table opposing face. In addition to increasing the radius of the inner surface of the face, the distance between the outer peripheral surface of the roller and the inner side of the table facing surface becomes smaller gradually as the radially outward direction of the table becomes constant, while the distance between the outer surface of the roller outer surface and the outer surface of the table facing surface becomes constant. A grinding surface shaping method for a vertical mill, characterized in that the radius of the outer and inner portions of the roller outer peripheral surface and the table opposing surface is determined. A vertical mill having a grinding surface having a shape determined by the grinding surface shape determination method of the vertical mill according to claim 1.