JP7053358B2 - Vertical mill - Google Patents

Description

The present invention relates to a vertical mill.

Vertical mills are used for the purpose of crushing objects to be crushed such as coal and slag, and the objects to be crushed between a table that rotates by a vertical axis and the upper surface of the table liner fixed on the table. It is a kind of crushing device having a roller for crushing.
In such an apparatus, as described in Patent Documents 1 to 5, it is known that a crushed surface is formed to be composed of a portion having a high hardness and a portion having a low hardness in order to improve the crushing efficiency.
In addition, a large number of annular material openings obtained by slicing a hard square pipe are arranged on the roller surface so as to face the surface, and a relatively soft metal melt is placed in the openings and, if necessary, the recesses between the annular materials. It is also known to fill and solidify to obtain rollers having areas of different hardness on the surface.
By adopting a roller whose surface has two kinds of hardness in this way, as the crushing apparatus is operated, the wear rate of the low hardness portion becomes high and the wear rate of the high hardness portion becomes slow. Then, the low-hardness portion is more worn to form a valley portion, and the high-hardness portion is not so worn to form a mountainous portion.
As a result, ridges and valleys are formed on the surface of the roller, and the object to be crushed is more reliably meshed between the rollers and the table by the ridges and valleys when further crushing.
Then, the pulverization efficiency can be improved by surely pulverizing the object to be pulverized.

As such a vertical mill is operated, the table liner surface and the roller surface in contact with the object to be crushed wear. When worn, the crushing efficiency is reduced, and in some cases, the table liner and rollers may be damaged.
Therefore, it is necessary to reduce the rate of wear by reducing the force required for crushing in order to perform stable crushing.
Further, in a roller in which each of the sliced pipes is welded to the surface, if the welding is not performed reliably, each pipe may be peeled off during use.

Special Table No. 08-501731 Japanese Unexamined Patent Publication No. 07-051585 Japanese Unexamined Patent Publication No. 63-143949 Japanese Patent No. 4579035 Japanese Patent No. 4680541

In the above background technique, by providing a portion having a high hardness and a portion having a low hardness on the roller surface of the vertical mill, the portion having a low hardness wears as the pulverization is performed. As a result, a convex portion having a high hardness portion and a concave portion having a low hardness portion are formed on the roller surface. Although the pulverization proceeds smoothly due to the formed unevenness, it is still insufficient to proceed with the pulverization more efficiently if the unevenness is provided only in the direction perpendicular to the rotation direction of the roller.
Therefore, the crushing efficiency can be further improved, that is, the crushing amount per unit time can be increased, the difficult-to-grind material can be crushed more efficiently, and the pressing force of the roller against the table can be reduced. Alternatively, it has been a problem to suppress slip generated between the roller or table liner and the object to be crushed, reduce the wear rate of the roller surface, and reduce power consumption and noise generation.

In order to solve the above problems, the present invention has adopted the following method.
It has a table liner that rotates by a vertical axis and a roller that can rotate by contacting the table liner and transmitting the rotational force of the table liner, and has a roller to which a rotation axis is connected to one side, and is supplied. The roller of the vertical mill in which the object to be crushed is crushed by entering between the table liner and the roller, and the shapes of the high hardness portion and the low hardness portion provided on the roller surface are specified.

Specifically, it is as follows.
It has a table liner that rotates by a vertical axis and a roller that can rotate by contacting the table liner and transmitting the rotational force of the table liner, and has a roller to which a rotation axis is connected to one side, and is supplied. A vertical mill in which the object to be crushed is crushed by entering between the table liner and the roller.
The surface of the roller on the side in contact with the object to be crushed is a vertical mill having the following a and / or b.
a. There is a high hardness part and a low hardness part, and the high hardness part intersects with a linear part extending in a direction parallel to the rotation direction of the roller at an angle of 60 degrees or less with respect to the linear part. It has a linear portion.
b. There is a high hardness part and a low hardness part, and the low hardness part intersects with a linear part extending in a direction parallel to the rotation direction of the roller at an angle of 60 degrees or less with respect to the linear part. It has a linear portion.

According to the present invention, the object to be crushed, including the difficult-to-grind material, can be pulverized efficiently, reliably and efficiently. As a result, the crushing capacity per unit time can be improved.
At the same time, it is possible to suppress the occurrence of slip between the table liner and the roller, or between the object to be crushed and the roller or the table liner, and it is possible to cause a pressing force between them.
As a result, noise and power consumption can be suppressed.

Vertical mill cross section Vertical mill internal perspective view View of Laura from the front An example of having a zigzag pattern with low hardness and a straight part parallel to the rotation direction provided on the roller surface. Another example of having a low hardness zigzag pattern on the roller surface and a straight line portion parallel to the direction of rotation. An example when the zigzag patterns provided on the roller surface intersect each other

(Vertical mill)
The vertical mill in the present invention has, for example, the structure shown in FIGS. 1 and 2, and has one or more rollers 5. The rotating shaft 7 is provided with a structure that extends and is supported on the outer surface side of the vertical mill.
The vertical mill has a crushing chamber 1 in it. In the crushing chamber 1, a table liner 2 having a crushing surface C on the upper surface forming the lower surface of the crushing chamber 1 is installed, and the table liner 2 can be rotated by a motor 3 by a vertical axis 4 during a crushing operation. .. The crushed surface C of the table liner 2 has a shape that can be brought into close contact with the surface of the roller 5.
During normal operation, the surface of the roller 5 is brought into contact with the surface of the roller 5 so as to be in contact with the crushing surface C provided on the upper surface of the table liner 2, and the object to be crushed is dropped and supplied from the central input port 6 or the like above the table liner into these gaps. do. During operation, the object to be crushed enters between the roller 5 and the table liner 2, so that the object to be crushed is crushed. At the same time, the rotational force of the table liner 2 is transmitted to the roller 5 via the object to be crushed, and the roller 5 is rotated by the rotation shaft 7.

(roller)
The roller 5 may be installed so that the rotating shaft 7 is horizontal, or may be provided so that the rotating shaft 7 is inclined as shown in FIG. The surface of the roller 5 is usually covered with a wheel 8 or the like on the side where the rotation shaft of the roller 5 is not provided, that is, the inner side of the crushing chamber 1.
The roller 5 is supported so as to be separable from the table liner 2 for repair / inspection and the like.

(The surface of the roller on the side in contact with the object to be crushed)
The surface of the roller in the present invention on the side in contact with the object to be crushed has a portion having a high hardness and a portion having a low hardness.
The pulverization efficiency can be improved by providing a portion having a high hardness and a portion having a low hardness at this time. In addition, when the surface is worn and repaired, the repair process can be simplified.
The method of providing the portion having a high hardness and the portion having a low hardness includes the following cases a and / or b.
a. There is a high hardness part and a low hardness part, and the high hardness part intersects with a linear part extending in a direction parallel to the rotation direction of the roller at an angle of 45 degrees or less with respect to the linear part. It has a linear portion.
b. There is a high hardness part and a low hardness part, and the low hardness part intersects with a linear part extending in a direction parallel to the rotation direction of the roller at an angle of 45 degrees or less with respect to the linear part. It has a linear portion.

As the vertical mill is operated and pulverized, the particularly low hardness portion of the roller surface wears. As a result, the portion having a low hardness becomes a concave portion and the portion having a high hardness becomes a convex portion, and unevenness is formed on the roller surface.
At this time, the pattern of the unevenness formed differs depending on whether the roller surface is either a or b. Further, the surface of one roller may have a surface of a and a surface of b.
What is important in the present invention is the linear portion extending in the direction parallel to the rotation direction of the roller and the angle of 45 or less with respect to the linear portion in both cases a and b. To have linear portions that intersect with each other. However, of the above two cases a and b, the case a is preferable in order to further exert the effect of the present invention.

(When the roller surface is a above)
In this case, in FIGS. 3 and 4 and 5 which are views of the roller viewed from the front, the convex portion having high hardness forms a zigzag pattern portion 9 such as a chevron pattern, and at the same time, the hardness extended in the rotation direction. Form a high straight line portion 10. The other portion, the overlay welded portion 11, is filled and formed by overlay welding a material having a low hardness. FIG. 4 is an enlarged view of a part of FIG. 3, and when these two parts are combined, the angle θ formed between the zigzag pattern portion and the straight line portion is 60 degrees or less, preferably 45 degrees or less. A portion having a high hardness having a shape open in the rotation direction of the roller 5 is formed. When the crushing step is continued by the rollers thus obtained, the surface is abraded, and the zigzag pattern portion 9 having a high hardness and the straight portion 10 having a high hardness become convex portions due to the low wear rate. The overlay welded portion 11 having a low hardness, which is another portion, becomes a recess due to the high wear rate.
The following phenomenon occurs when the roller having such a shape having a high hardness portion rotates.
At a position where the crushed surface of the table liner and the surface of the roller face each other, the object to be crushed enters between the roller and the table liner due to the rotation of the roller and the table liner. The entered object to be crushed is put between the roller and the table liner, and at the same time, a force is applied by the pressure generated between the roller and the table liner to be crushed.
In the object to be crushed supplied to the gap formed between the roller and the table liner, the zigzag pattern portion and the straight portion intersect at an angle of 60 degrees or less, and the intersecting portion is directed toward the rotation direction of the roller. Due to the high hardness portion having an open shape, it is further pushed toward the gap. When the temperature is 45 degrees or less, the object to be crushed can be pushed in more strongly.

In this way, the intersecting portion of the pattern portion and the straight portion exerts an action of positively supplying between the roller and the table liner while collecting the objects to be crushed existing in the surroundings.
As a result, the pressure generated between the table liner and the rollers can be reduced. Since the roller can efficiently bite the object to be crushed, the tension pressure (force that presses the roller against the table liner) can be reduced by about 20%. Then, the pulverization efficiency can be improved, and at the same time, the wear rate of the surface of the roller or the table liner can be reduced.

(When the roller surface is b above)
In FIGS. 3 to 5, the non-rigid zigzag pattern portion 9 and the non-rigid straight portion 10 are made of a material having a low hardness. The hard overlay welded portion 11 which is a portion in between is filled and formed by overlay welding a material having a high hardness. When the pulverization step is continued by the rollers thus obtained, the surface is abraded, and the non-rigid zigzag pattern portion 9 and the non-rigid straight portion 10 become recesses due to the high wear rate. The hard overlay welded portion 11 which is the other portion becomes a convex portion because the wear rate is low. In other words, the concave portion existing between the convex portions has a shape formed by combining a zigzag pattern portion such as a so-called chevron pattern and a straight portion extending in the rotational direction at the same time. By combining these two portions, the angle θ of the formed convex portion is 60 degrees or less, preferably 45 degrees or less, and the angle is arranged in the rotation direction of the roller.
FIGS. 4 and 5 are examples of patterns when the zigzag pattern portions do not intersect each other, and FIG. 6 is an example of a pattern in which the zigzag pattern portions intersect with each other.
The following phenomenon occurs when the roller having such a shape having a high hardness portion rotates.
At a position where the crushed surface of the table liner and the surface of the roller face each other, the object to be crushed enters between the roller and the table liner due to the rotation of the roller and the table liner. The entered object to be crushed is put between the roller and the table liner, and at the same time, a force is applied by the pressure generated between the roller and the table liner to be crushed.
At this time, the object to be crushed supplied to the gap formed between the roller and the table liner has an angle in which the shape of the surface pattern (top) formed by the zigzag pattern and the straight line is a polygon such as a triangle or a quadrangle. The convex portion having an angle of 60 degrees or less further causes the angle to expand the object to be crushed in the direction perpendicular to the rotation direction by the rotation of the roller.
Therefore, the crushing force applied to the object to be crushed can be made uniform, and pulverization can be performed more efficiently.
As a result, it is possible to improve the pulverization efficiency without particularly increasing the pressure generated between the table liner and the roller, and at the same time, reduce the wear rate of the surface of the roller or the table liner.
As a result, the pressure generated between the table liner and the rollers can be reduced. Since the roller can efficiently bite the object to be crushed, the tension pressure (force that presses the roller against the table liner) can be reduced by about 20%. Then, the pulverization efficiency can be improved, and at the same time, the wear rate of the surface of the roller or the table liner can be reduced.

Further, in the case of a and b above, the width of the zigzag pattern can be any width with respect to the width direction of the surface of the roller (the direction perpendicular to the rotation direction of the roller), which is preferable. Is 20 mm to 50 mm. If the width is too narrow or too wide, the effect of improving the crushing efficiency will be low.
Further, in both the case of a and the case of b, it is preferable to set the angle to 60 degrees or less, but the angle can be further set to 45 degrees or less, 35 degrees or less, and 25 degrees or less.
The linear portion extending in the direction parallel to the rotation direction of the roller and the linear portion intersecting the linear portion at an angle of 45 degrees or less may be a combination of straight lines. Further, at the intersection, at least one of the linear portions may be a curved line.
According to the present invention, a frame having a shape obtained by slicing a square pipe with a high hardness portion is not welded to the roller surface, and both the high hardness portion and the low hardness portion are formed by overlay welding, so that the frame does not peel off. ..

(Method of providing a part with high hardness and a part with low hardness on the roller surface)
Such a surface can be obtained by either a step of newly creating a roller or a step of repairing when the surface of an existing roller is worn.
First, on the surface of the roller, a convex portion consisting of a linear portion extending in a direction parallel to the rotation direction of the roller and a linear portion intersecting the linear portion at an angle of 45 degrees or less is formed. It is provided by means such as fill welding.
Method of using a roller in the case of a: When these linear portions are high hardness portions, they are filled with a metal constituting a portion other than the linear portion provided above, that is, a portion having a low hardness with respect to the concave portion. ..
Method of using a roller in the case of b: When these linear portions are low hardness portions, they are filled with a metal constituting a portion other than the linear portion provided above, that is, a portion having a high hardness with respect to the concave portion. ..

<Overlay welding>
Known means can be adopted as means for overlay welding these and filling the concave portions formed on the surface with metal. Further, the structure having the portions a and / or b in the present invention can be provided not only on the roller but also on the surface of the table liner independently of the structure of the roller surface. At this time, it is possible to obtain an effect in which the effects of the respective structures of the roller surface and the table liner surface are combined.
The crushed surface on the surface of the roller 5 and the table liner 2 is worn by the operation of the vertical mill. Therefore, in order to recover the worn crushed surface, overlay welding is performed to form a new overlay surface. In overlay welding, a welding jig such as a welding wire is brought close to the surface of the roller 5 or the table liner 2 for welding. As a welding jig used for such overlay welding, a well-known jig can be adopted.

As the equipment for overlay welding required for overlay welding on the surface of the roller 5, it is a known overlay welding facility. A pipeline for supplying the weld wire to be overlaid is installed from the outside to the inside of the vertical mill, and the inner end of the vertical mill is installed near the welding torch. The welding torch is installed close to the roller surface so that overlay welding can be performed on the roller surface. A well-known welding torch can be adopted, and a welding wire used for conventional overlay welding can be adopted.
In the state of being installed in this way, the roller 5 is separated from the crushed surface C of the table liner 2 as needed, and overlay welding is performed while rotating the roller 5 by the above means. When the overlay welding jig is moved in the rotation axis direction of the roller by a predetermined width for each rotation of the roller 5, the overlay welding welding beads can be adjacent to each other for each rotation. As a result, each time the rotation of the roller progresses, it is built up on the roller surface.
As a result, it is possible to form a linear portion extending in a direction parallel to the rotation direction of the roller in the present invention. Strictly speaking, the directions are not exactly parallel because the rollers 5 are moved in the rotation axis direction of the rollers by a predetermined width for each rotation.
As for the rotation speed of the roller, it is preferable that the rotation speed of the surface to be overlaid welded is 300 to 1500 mm / min. If it is less than 300 mm / min, the efficiency of overlay welding deteriorates, and if it exceeds 1500 mm / min, the welding speed is exceeded and sufficient repair becomes difficult.
Further, the wall thickness can be up to about 50 mm as a metal repair layer on the roller surface or the table liner surface by overlay welding.

Although not shown, the thickness of the part of the roller that is in contact with the object to be crushed is non-contact so that it can be measured before, during, and after overlay welding. A device for measuring the surface shape by a laser or the like may be provided.
When the roller surface is repaired by overlay welding, the surface shape can be any shape. The uneven shape extending in the approximate circumferential direction of the roller surface may remain, and then the surface may be ground to obtain a smoother surface.
Further, in overlay welding, when the welding jig is moved in the axial direction of the roller by the width of the overlay for each rotation of the roller as described above, overlay welding is performed along the roller surface like a single stroke. can do. Further, by reciprocating the welding jig to an arbitrary width in the axial direction of the roller, a wavy pattern such as a so-called chevron pattern is formed on the roller surface, and the object to be crushed is formed between the table liner 2 and the roller 5. It can be bitten more reliably.

As a drive device including a motor for rotating a roller of about 4 tons (roller diameter: about 1,500 mm) at a peripheral speed of about 1,000 mm / min for performing good overlay welding, for example, the following. The specifications are listed. This drive device consists of only the following motors or integrated with a gearbox.
When the gearbox was used, the following gear ratio was used, and the number of revolutions was lowered to increase the torque. In addition, rotary ground was also used.
Motor: 3-phase x 200V x 50w x 4-pole motor (gear motor)
Gear ratio: 1 / 1,800
Maximum rotation speed at the end of the drive shaft: 1 rpm (60 Hz), 0.83 rpm (50 Hz)
Maximum torque at the end of the drive shaft 32kg-m (60Hz), 38kg-m (50Hz)
Rotary ground capacity: 1,000 Amp

1 ... Grinding chamber 2 ... Table liner 3 ... Motor 4 ... Vertical axis 5 ... Roller 6 ... Central input port 7 ... Rotating shaft 8 ... Wheel 9 ... Zigzag pattern part 10 ... Straight line part 11 ... Overlay welded part C ... Crushed surface

Claims (1)

It has a table liner that rotates by a vertical axis and a roller that can rotate by contacting the table liner and transmitting the rotational force of the table liner, and has a roller to which a rotation axis is connected to one side, and is supplied. A vertical mill in which the object to be crushed is crushed by entering between the table liner and the roller.
The surface of the roller on the side in contact with the object to be crushed is a vertical mill having the following a and / or b.
a. There is a high hardness part and a low hardness part, and the high hardness part intersects with a linear part extending in a direction parallel to the rotation direction of the roller at an angle of 60 degrees or less with respect to the linear part. It has a linear portion.
b. There is a high hardness part and a low hardness part, and the low hardness part intersects with a linear part extending in a direction parallel to the rotation direction of the roller at an angle of 60 degrees or less with respect to the linear part. It has a linear portion.

Images