JP2002059016A - Vertical mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical mill capable of preventing the penetration of dust into the space in the periphery of a bearing to enable continuous operation over a longer period of time. SOLUTION: The vertical mill is provided with a seal mechanism for allowing compressed air to flow toward the space in the mill through a labyrinthine air passage formed by an annular member 101 attached on the side of a roller and an annular member 102 attached on the side of a fixed shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical mill for performing grinding by biting an object to be ground into a gap between a rotary table and a roller.

[0002]

2. Description of the Related Art A vertical mill (pulverizer) as shown in FIG. 1 is widely used as a type of pulverizer for pulverizing limestone, slag, cement raw materials, coal and the like. This crusher 10 is a disk-shaped table 11 using a motor or the like as a driving force.
And crushing is performed by causing the material to be crushed to bite between a plurality of rollers 12 rotatably disposed on the outer peripheral upper surface thereof, and the processing capacity is about 10 t / h. 400 t / h for large to large
There are also things that extend.

That is, the material to be crushed is supplied to the center of the rotary table 11 from a raw material chute 13 disposed above the crusher, and is dispersed in the outer peripheral direction by centrifugal force. It is crushed by being bitten by.

The crusher 10 has a structure in which hot air is supplied from below the outer periphery of the table 11. An induction fan (not shown) is provided on the powder outlet side, and the inside of the mill is maintained at about -8 kPa (Gauge). Hot air is introduced from the outside of the mill by this negative pressure and blows up the pulverized material upward. At this time, the coarse pulverized material falls again on the table 11 and is pulverized. The powder blown up by the hot air is further classified by a classifier 14 disposed above the roller 12 and discharged from the top of the mill.
At that time, the coarse powder falls on the turntable 11 and is ground again, as described above. By introducing hot air in this way, it is possible to simultaneously dry, crush and classify the material to be crushed.

Here, the structure of the roller 12 will be described with reference to FIG. FIG. 2 is an enlarged sectional view schematically showing the periphery of the roller.

The roller 12 is mainly composed of a roller boss 23 rotatably mounted on a roller shaft 21 as a fixed shaft via a rolling bearing 22, and a roller tire 24 as a consumable part mounted on the outer periphery thereof. , And a sealing mechanism of the bearing portion. Hereinafter, these rotating parts are collectively referred to as a roller 12. In addition, in order to make the roller 12 which is the rotating portion easy to understand, only the rotating portion is shown by oblique lines in FIG.

The inside of the crusher 10 has a high-concentration dust (dust) atmosphere due to the blown-up material to be crushed, and it is required to lubricate the rolling bearings 22 with clean lubricating oil in this atmosphere. Therefore, it is necessary to protect the space around the bearing from dust.

For this reason, a cover serving as a roller boss cover 25 is attached to the front end of the roller boss 23, and a roller boss cover 26 is similarly attached to the rear end of the roller boss 23 to protect the bearing.

However, since the non-rotating roller shaft 21 exists at the center of the roller 12, the dust in the mill is prevented from entering the space around the bearing (that is, the space surrounded by the roller 12 and the roller shaft 21). It is necessary to provide a sealing mechanism.

Further, since the roller 12 vibrates violently due to the pulverizing operation and the rolling bearing 22 has some backlash, the roller 12 and the roller shaft 21 relatively vibrate by about 0.6 mm. I have. For this reason, it is impossible to seal by setting the gap between the roller boss cover 26 and the fixed shaft side to zero, and a flexible sealing mechanism is required.

[0011]

In a conventional vertical mill in which grinding is performed by biting an object to be crushed into a gap between the rotary table 11 and the roller 12, in order to prevent dust from entering the space around the bearing. , A plurality of seal mechanisms as shown in FIG. FIG. 4 is a detailed view of a portion A in FIG. In addition, the roller 12 which is a rotating unit
In order to make the part easy to understand, only the rotating part is shown by oblique lines in FIG.

First, the roller boss cover 26 is set so as to minimize the gap W between the tip of the seal member 27 and the roller boss cover 26. The seal member 27 is attached to an arm 28 that supports the roller shaft 21,
(See FIG. 2), which is a part that plays a role of preventing the air from leaking into the mill by the sliding mechanism.

However, since the roller boss cover 26 and the seal member 27 are relatively vibrating, it is necessary to secure a gap W of, for example, about 1.5 mm, and coarse powder enters the space around the bearing. Can be prevented to some extent, but has almost no function of preventing intrusion of fine powder. Further, the gap W has a problem that wear is likely to progress due to biting of coarse powder.

Secondly, an annular member 41 called a seal ring is attached to the end of the roller boss cover 26. Between the annular member 41 and the roller shaft 21, for example, a double ceramic packing 42 is provided. Wool felt 4
3 has a sealing mechanism provided.

However, there is a case where the above-mentioned sealing mechanism cannot be provided with high accuracy over the entire circumference of the roller shaft 21. Further, when dust in the mill reaches this portion, abrasion proceeds so as to bite it. I do. Further, oil leaked from the bearing portion may lose the flexibility of the wool felt 43, and it is difficult to maintain the sealing function for a long time.

Third, on the bearing side of the roller boss cover 26, a seal mechanism called a mechanical seal 44 is provided. This is a mechanism for pressing the annular member 45 against the annular member 41 by pressing the two annular members 45 and 46 in the axial direction (horizontal direction on the paper surface of FIG. 4) by a spring or the like. Even if the members are worn to some extent, the sealing is maintained, so that the sealing effect can be expected for a long time.

However, in many cases, the above mechanical seal does not satisfy the life required for practical use. For example, in a vertical mill used in a raw material pulverizing step in cement production, the average life of a mechanical seal is about 7 months. In cement production in which continuous and long-term production is performed, these parts are disassembled every break. There is a need to perform maintenance and replacement. At the same time, this means that the upstream sealing mechanism (ie, the first and second sealing mechanisms) is not functioning.

Further, since the rotating portion (roller side) and the fixed portion (roller shaft side) are relatively vibrating, the sliding surface of the mechanical seal does not maintain a good contact state and slides without vibration. There is a problem that the wear is intense as compared with the mechanical seal which performs. This causes a problem that the metal powder of the worn mechanical seal is mixed into the lubricating oil of the bearing portion.

An object of the present invention is to provide a vertical mill, in particular, a vertical mill capable of more reliably preventing dust from entering the space around a bearing in a roller mill and enabling continuous operation for a longer period. .

[0020]

The constitution of the present invention which has been achieved to achieve the above object is as follows.

That is, the present invention relates to a vertical mill in which grinding is performed by biting an object to be ground into a gap between a rotary table and a roller supported by a fixed shaft, wherein the fixed shaft has a predetermined gap with the roller. To attach the sealing member,
It is characterized by having a sealing mechanism for flowing air from the gap to the space inside the mill.

A further feature of the vertical mill of the present invention is that the sealing mechanism is a mechanism for flowing air to the space inside the mill by a differential pressure between the internal pressure of the mill and the atmospheric pressure.
"The seal mechanism is a mechanism for flowing pressurized air to the inside space of the mill.", "The seal mechanism is formed by an annular member attached to the roller side and an annular member attached to the fixed shaft side. A mechanism for flowing air or pressurized air to the inside of the mill through a maze-shaped airway ”.

According to the vertical mill of the present invention, by introducing air in a direction opposite to the direction in which dust in the mill enters the bearing portion, dust is effectively prevented from entering the bearing portion. Can be.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vertical mill according to the present invention is a so-called roller mill that performs grinding by biting a material to be ground into a gap between a rotary table and a roller. The configuration can be the same as that of a vertical mill as shown in FIGS. 1 and 2, for example.

The most significant feature of the present invention is that a seal mechanism is provided for flowing air toward the inner space of the mill through a predetermined gap formed between a roller portion as a rotating portion and a roller shaft portion as a fixed portion. It is in the point.

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

(First Embodiment) FIG. 6 is a partial cross-sectional view showing a sealing mechanism of a vertical mill according to this embodiment.
FIG. In FIG. 6, the same members as those in FIG. 4 are denoted by the same reference numerals.

The seal mechanism of the present embodiment differs from the above-described structure of FIG. 4 in that an air suction port 61 is formed at a predetermined position of a seal member 27 attached to a fixed shaft (roller shaft 21). I have.

The seal member 27 is fixed to the roller shaft 21 via the arm 28, and is provided with a gap W from the roller boss cover 26.

As described above, since the roller boss cover 26 and the seal member 27 are relatively vibrating, it is necessary to secure the gap W of about 1.5 mm. Further, since the inside of the mill has a high-concentration dust (dust) atmosphere due to the material to be pulverized, fine powder enters the space surrounded by the roller 12 and the roller shaft 21 via the gap W (the space around the bearing portion). The environment is easy to invade.

On the other hand, the internal space of the mill is -8 kPa (Gaug).
e) The negative pressure of about e) is maintained, so that the air suction port 61 is provided in the seal member 27 as in this example, whereby air flows from the gap W to the space inside the mill due to these differential pressures. Become. In other words, the air supplied from the air suction port 61 is supplied into the mill through the gap W in a direction opposite to the dust entry path, so that dust can be prevented from entering the bearing portion.

Although the opening area of the air suction port 61 is not particularly limited, the opening area of the air suction port 61 and the number thereof actually determine the amount of air leak into the mill. Increase in the heat loss of the mill and the power of the induction fan.

As described above, in this embodiment, the air is caused to flow toward the space inside the mill by the differential pressure between the pressure inside the mill and the atmospheric pressure. Dust contamination can be prevented, equipment troubles caused by dust contamination, and regular disassembly and maintenance can be eliminated, and the mill can be operated for a long period of time.

(Second Embodiment) FIG. 7 is a partial cross-sectional view showing a sealing mechanism of a vertical mill according to this embodiment.
FIG. In FIG. 7, the same members as those in FIG. 4 are denoted by the same reference numerals.

The seal mechanism of the present embodiment includes a dust mixing prevention plate 7
1 is different from the first embodiment.

The dust mixing prevention plate 71 is attached to the seal member 27. An air suction port 72 is formed on the dust mixing prevention plate 71 to prevent the air from leaking into the mill more than necessary.

In a vertical mill such as the present invention, abrasion holes 73 (see FIG. 7) may be formed in the seal member 27 due to dust inside the mill due to long-term operation. Phenomenon flowing into has been confirmed. For this reason, in the first embodiment described above, there is a risk that dust may enter the bearing portion when the wear hole 73 is formed. However, by providing the dust mixing prevention plate 71 as in this example, it is possible to prevent dust from leaking into the bearing portion when leaked.

In this embodiment, as in the first embodiment,
Air flows from the gap W to the space inside the mill due to the differential pressure between the atmospheric pressure and the pressure inside the mill.

Although the opening area of the air suction port 72 is not particularly limited, the opening area of the air suction port 72 and the number thereof substantially determine the amount of air leaking into the mill as in the case of the atmospheric suction port 61. Therefore, the air suction port 6
As in the case of 1, the opening area and the number should be set appropriately. It is also possible to increase the number of air inlets 72 while observing the dust intrusion state.

In an actual form, the air suction port 72 is provided with several or more holes in the dust mixing prevention plate 71, and a screw is cut in the hole. It is preferable because it can be optimized.

As a specific example, in a vertical type mill LM41 manufactured by Ube Industries, an air suction port 61 is provided, and a plurality of holes having a diameter of about 10 mm are provided as an air suction port 72. It was possible to effectively prevent dust from entering the inside of the mill during operation.

As described above, in the present embodiment, air is caused to flow into the space inside the mill by the differential pressure between the internal pressure of the mill and the atmospheric pressure, and the dust mixing prevention plate 71 is provided. It is possible to prevent the problem more effectively, and eliminate equipment troubles due to dust mixing and periodic disassembly and maintenance, thereby enabling a long-term operation of the mill. In addition, the amount of air leak into the mill can be easily set with an extremely simple configuration, and it is also possible to minimize operational loss due to leak air.

(Third Embodiment) FIG. 8 is a partial cross-sectional view showing a sealing mechanism of a vertical mill according to this embodiment.
FIG. In FIG. 8, the same members as those in FIG. 4 are denoted by the same reference numerals.

In the sealing mechanism of this embodiment, an air purge pipe 81 is provided inside the roller shaft 21 and the air purge pipe 8 is provided.
1 to atmosphere or 3 kPa through air purge hole 82
It differs from the configuration shown in FIG. 4 in that it can supply pressurized air of about (Gauge).

The thickness and length of the air purge pipe 81 may be of any shape as long as the required amount of air is supplied, and the material is not particularly limited. For example, easily available water pipes and gas pipes can be used. In some cases, a pipe corresponding to the vertical mill is already provided, and in this case, it is possible to divert the pipe.

The size of the air purge hole 82 may be any size as long as the required amount of air is supplied, and the number is not limited. However, in the actual form, the number is usually limited to several in consideration of processing and the like.

Since a sufficient space is formed along the circumference around the outlet of the air purge hole 82 of this embodiment, the purge air supplied from the air purge hole 82 spreads quickly in the circumferential direction, and the gap W Blow unevenness does not occur in the part, and the air can be quickly supplied to the inside of the mill with a small resistance to prevent the air from flowing back to the bearing part.

In this embodiment, the purge air supplied from the air purge pipe 81 is supplied to the inside of the mill from the gap W between the seal member 27 and the roller boss cover 26 through the purge air hole 82. As a result, air is supplied in the direction opposite to the dust entry path, so that it is possible to effectively prevent dust from entering the bearing.

(Fourth Embodiment) FIG. 9 is a partial sectional view showing a sealing mechanism of a vertical mill according to the present embodiment.
FIG. In FIG. 9, the same members as those in FIG. 4 are denoted by the same reference numerals.

The seal mechanism of the present embodiment differs from the third embodiment in that an air purge amount control plate 91 is provided.

The air purge amount control plate 91 is a seal member 27
Attached to. A purge air discharge port 92 and an air suction port 93 are formed on the air purge amount control plate 91 to prevent the purge air from leaking into the mill more than necessary.

In this embodiment, as in the third embodiment,
Purge air can be supplied into the mill from the gap W. That is, the purge air supplied from the air purge pipe 81 is supplied into the mill from the gap W through the purge air hole 82, the purge air discharge port 92, and the air suction port 93.

A plurality of purge air discharge ports 92 are formed on the air purge amount control plate 91 to function as purge air discharge ports. For this reason, the opening area and quantity need only be secured to the extent that the purge air can be discharged without difficulty. However, in the event that dust is leaked, the total amount of dust should be minimized from flowing into the bearing. The area should be set appropriately. Further, it is preferable that a thread is cut in the purge air discharge port 92, the number thereof is set relatively large, and the stopper is appropriately plugged, so that the air flow rate can be appropriately adjusted quickly.

The opening area and the number of the air suction port 93, like the purge air discharge port 92, effectively determine the air flow rate into the inside of the mill. Therefore, the opening area and the number should be appropriately set similarly to the purge air discharge port 92. It is also possible to increase the number of air inlets 93 while observing the dust intrusion state.

In the actual mode, the air suction port 93 is provided with several or more holes in the air purge amount control plate 91, like the air suction port 72, and a screw is cut in the hole, so that the air suction port is determined to be unnecessary. It is preferable that the setting is made by closing the hole, because the adjustment can be quickly performed.

As a specific example, in the vertical type mill LM41 manufactured by Ube Industries, 3
By arranging four holes of 穴 inch and 24 holes of 12 mm in diameter as the air inlet 93, it was possible to effectively prevent dust from entering the inside of the mill during normal operation.

(Fifth Embodiment) FIG. 10 is a partial sectional view showing a sealing mechanism of a vertical mill according to the present embodiment, and corresponds to FIG. 4 described above. In FIG. 9, the same members as those in FIG. 4 are denoted by the same reference numerals.

The seal mechanism of this embodiment includes an annular member 101 attached to the roller 12 as a rotating portion and an annular member 102 attached to the roller shaft 21 as a fixed portion.
This forms a maze-like airway, and the air purge pipe 81
3 kPa (Gauge) through this maze-shaped airway
The third embodiment differs from the third embodiment in that a certain amount of pressurized air or air can be supplied. The air purge pipe 81 is the same as in the third embodiment.

In order to make the roller 12 which is the rotating part of this example easier to understand, only the rotating part is shown by hatching in FIG.

The annular members 101 and 102 are the roller shaft 2
1 and the roller boss cover 26 and are combined with each other to form a narrow labyrinth-like gap, and this gap serves as an airway for purge air. This airway is called a maze airway.

As shown in FIG. 10, the air purge hole 82
The roller shaft 21 is provided at the starting point of the maze airway, and connects the air purge pipe 81 to the maze airway. The size of the air purge holes 82 may be any size as long as the required air volume is supplied, and the number is not limited. However, in an actual form, the number may be usually limited to several in consideration of processing and the like.

It is preferable that the clearance between the maze airways is smaller because the required amount of purge air is smaller.
And the roller shaft 21 are both vibrating irregularly, and in consideration of avoiding metal-to-metal contact accompanying this, 1-4 m
It is preferable to set to about m. Further, by making the airway longer, it is possible to more reliably prevent dust from entering the bearing portion side, and it is preferable that the total length be set as long as the space allows.

It is preferable to leave a sufficient space around the outlet of the air purge hole 82 along the circumference as shown in FIG. This makes it possible for the purge air supplied from the air purge holes 82 to quickly spread in the circumferential direction, and to prevent the occurrence of uneven blowing at each part on the circumference. Further, although there is no particular limitation on the cross-sectional shape of the space provided around the outlet of the air purge hole 82, air is quickly supplied with low resistance to the inside of the mill, that is, downstream of the purge air, and conversely, air is supplied to the bearing side. In consideration of preventing backflow, it is preferable to provide a space having a wedge-shaped cross section that becomes thinner in the downstream side, that is, in the direction opposite to the bearing side.

In the present embodiment, the purge air supplied from the air purge pipe 81 passes through the maze airway formed by the annular members 101 and 102 from the purge air hole 82, and passes through the gap W between the seal member 27 and the roller boss cover 26 into the mill. Supplied to As a result, air is supplied in the direction opposite to the dust entry path, so that it is possible to effectively prevent dust from entering the bearing. In particular, since there is no contact portion between the rotating portion and the fixed portion, and no sliding portion, it is not necessary to take measures such as wear.

(Sixth Embodiment) FIG. 12 is a partial sectional view showing a sealing mechanism of a vertical mill according to this embodiment, and corresponds to FIG. 4 described above. In FIG. 12, the same members as those in FIG. 4 are denoted by the same reference numerals.

The seal mechanism of this embodiment differs from the fifth embodiment in that an air purge amount control plate 91 is provided. The air purge amount control plate 91 is the same as in the fourth embodiment.

In this embodiment, the purge air supplied from the air purge pipe 81 passes through the maze airway formed by the annular members 101 and 102 from the purge air hole 82.
Further, the air is supplied from the gap W into the mill through the purge air discharge port 92 and the air suction port 93. As a result, air is supplied in the direction opposite to the dust entry path, so that it is possible to effectively prevent dust from entering the bearing.

Also, in this embodiment, since there is no contact portion between the rotating portion and the fixed portion, and no sliding portion, no countermeasures such as abrasion are required. Further, in this example, since the amount of air leaking into the mill can be easily set, loss of heat and power due to leak air can be minimized.

(Seventh Embodiment) FIG. 13 is a partial sectional view showing a sealing mechanism of a vertical mill according to this embodiment, and corresponds to FIG. 4 described above. In FIG. 13, the same members as those in FIG. 4 are denoted by the same reference numerals.

The seal mechanism of the present embodiment is different from the sixth embodiment in that an air suction port 61 is formed at a predetermined position of the seal member 27. The atmosphere suction port 61 is the same as in the first embodiment.

The air suction port 61 allows necessary leak air to be taken in from the atmosphere, and functions as an excess air discharge port when the amount of purge air supplied from the air purge pipe 81 is larger than the amount of leak air in the mill.

In this embodiment, the purge air supplied from the air purge pipe 81 passes through the maze airway formed by the annular members 101 and 102 and the purge air discharge port 92 from the purge air hole 82, and further along with the atmosphere from the atmosphere suction port 61. Alternatively, the remainder partially discharged from the air suction port 61 is supplied into the mill through the gap W through the air suction port 93. As a result, air is supplied in the direction opposite to the dust entry path, so that it is possible to effectively prevent dust from entering the bearing.

Also, in this embodiment, since there is no contact portion between the rotating portion and the fixed portion, and no sliding portion, it is not necessary to take measures such as abrasion, and the amount of air leaking into the mill can be easily set. Therefore, loss of heat and power due to leak air can be minimized.

(Eighth Embodiment) FIG. 14 is a partial sectional view showing a sealing mechanism of a vertical mill according to the present embodiment, and corresponds to FIG. 4 described above. In FIG. 14, the same members as those in FIG. 4 are denoted by the same reference numerals.

The seal mechanism of this embodiment is different from the fifth embodiment in that pressurized air is supplied from the inside of the roller shaft to the maze airway, instead of the space surrounded by the roller 12 and the roller shaft 21 (the bearing portion). Pressurized air is supplied into the peripheral space), and a purge air supply unit 141 is formed in the annular member 101 attached to the roller 12 side to communicate with the maze airway.

In this example, the purge air supplied to the space around the bearing portion passes through the maze airway formed by the annular members 101 and 102 from the purge air supply portion 141 and the gap between the seal member 27 and the roller boss cover 26 is formed. W feeds into the mill. As a result, air is supplied in a direction opposite to the dust entry path, so that dust can be effectively prevented from entering the bearing portion. Also in this example, since there is no contact portion between the rotating portion and the fixed portion, and no sliding portion, it is unnecessary to take measures such as wear.

The vertical mill of the present invention is not limited to the embodiment described above, and can be appropriately modified within the gist of the present invention. For example, members and the like specially provided in each embodiment can be replaced, or the two embodiments can be appropriately combined.

[0078]

As described above, the vertical mill according to the present invention has the following advantages.

(1) A seal member is attached to the fixed shaft (roller shaft) side with a predetermined gap from the roller, and air is allowed to flow to the space inside the mill through the gap, so that the periphery of the bearing portion is It is possible to prevent dust from entering the space, eliminate equipment troubles due to dust mixing, and eliminate short-term regular disassembly and maintenance, and realize a vertical mill capable of continuous operation for a longer period.

(2) When air is made to flow toward the inner space of the mill by utilizing the pressure difference between the internal pressure of the mill and the atmospheric pressure, the dust in the peripheral space of the bearing portion can be extremely simply configured. Intrusion can be prevented. Further, by configuring the number of the air suction ports and the like to be variable, it is possible to easily set the amount of air leak into the mill, and it is possible to minimize operational loss due to leak air.

(3) When air is made to flow toward the inner space of the mill using pressurized air, it is possible to more effectively prevent dust from entering the space around the bearing.

(4) In the case where a maze airway is formed by attaching an annular member to the roller side and the fixed shaft (roller shaft) side, and air flows to the space inside the mill via the maze airway, Intrusion of dust into the space around the bearing can be extremely effectively prevented. Further, it is possible to have a structure without a contact portion between the rotating portion and the fixed portion and a sliding portion, and a vertical mill capable of continuous operation for a longer period is realized. . Further, for example, when an air purge amount control plate or the like is provided, the amount of air leak into the mill can be easily set, and the operational loss due to leak air can be minimized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one configuration example of a vertical mill.

FIG. 2 is an enlarged cross-sectional view schematically showing the periphery of a roller of a vertical mill.

FIG. 3 is a diagram showing a rotating part and a fixed part in FIG. 2 in distinction;

FIG. 4 is a cross-sectional view for explaining a sealing mechanism in a conventional vertical mill.

FIG. 5 is a diagram showing the rotating part and the fixed part in FIG. 4 separately;

FIG. 6 is a cross-sectional view for explaining a seal mechanism according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a seal mechanism according to a second embodiment of the present invention.

FIG. 8 is a sectional view illustrating a seal mechanism according to a third embodiment of the present invention.

FIG. 9 is a cross-sectional view for explaining a seal mechanism according to a fourth embodiment of the present invention.

FIG. 10 is a cross-sectional view illustrating a seal mechanism according to a fifth embodiment of the present invention.

FIG. 11 is a diagram showing the rotating part and the fixed part in FIG. 10 in distinction;

FIG. 12 is a cross-sectional view illustrating a seal mechanism according to a sixth embodiment of the present invention.

FIG. 13 is a cross-sectional view illustrating a seal mechanism according to a seventh embodiment of the present invention.

FIG. 14 is a cross-sectional view for explaining a seal mechanism according to an eighth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vertical mill (pulverizer) 11 Rotary table 12 Roller 13 Raw material chute 14 Classifier 21 Roller shaft 22 Rolling bearing 23 Roller boss 24 Roller tire 25, 26 Roller boss cover 27 Seal member 28 Arm 29 Mill casing 41 Seal ring 42 Ceramic Packing 43 Wool felt 44 Mechanical seal 45, 46 Seal ring 61 Atmospheric suction port 71 Dust entry prevention plate 72 Air suction port 73 Wear hole 81 Air purge pipe 82 Air purge hole 91 Air purge amount control plate 92 Purge air discharge port 93 Air suction port 101, 102 Annular member 141 Purge air supply unit

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yuji Sato 2209 Aomi, Aomi-cho, Nishikubiki-gun, Niigata Prefecture Inside the Aomi Plant of Denki Kagaku Kogyo Co., Ltd. Inside the Omi Plant of the Chemical Industry Co., Ltd. (72) Kazuo Yamazaki, 2209 Aomi, Omi-cho, Nishikubiki-gun, Niigata Prefecture Inside the Omi Plant of Denki Kagaku Kogyo Co., Ltd. Inside the Omi Plant of the Chemical Industry Co., Ltd. (72) Inventor Tomoaki Nishioka 2209 Aomi, Aomi-cho, Nishikubiki-gun, Niigata Prefecture Inside the Omi Plant of Denki Kagaku Kogyo Co., Ltd. F term in the Aomi Plant of Chemical Industry Co., Ltd. (reference) 4D063 EE03 EE12 EE21 GA06 GA07 GA08 GC27

Claims (4)

[Claims] 1. A vertical mill in which grinding is performed by biting an object to be crushed into a gap between a rotary table and a roller supported by a fixed shaft, wherein a sealing member having a predetermined gap with the roller is provided on the fixed shaft side. And a sealing mechanism for flowing air from the gap to the space inside the mill. 2. The vertical mill according to claim 1, wherein the sealing mechanism is a mechanism for flowing air to a space inside the mill by a differential pressure between a pressure inside the mill and an atmospheric pressure. 3. The vertical mill according to claim 1, wherein the sealing mechanism is a mechanism for flowing pressurized air to a space inside the mill. 4. The seal mechanism sends air or pressurized air to a space inside the mill through a maze-like airway formed by an annular member attached to a roller side and an annular member attached to a fixed shaft side. The vertical mill according to claim 2 or 3, wherein the mill is a flowing mechanism.