JPH057785A - Vertical roller mill - Google Patents

Abstract

PURPOSE:To enable the rolling of grains into fine particles without deteriorating grain size classification effects and also the appropriate selection of an extent to which the rolling to fine particles is allowed by turning the crushing chamber of a vertical rotary roller to a blocked state and forming a wind box between the crushing chamber of a housing and a classification recovery part with the provision of a feed aperture on the wind box. CONSTITUTION:A vertical shaft 14 driven by a means for driving 13 is installed at the bottom of a housing 10, and an uplight roller 1 and a means for stirring 21 are arranged on the vertical shaft 14. Then, after crushing a material to be crushed using the uplight roller 1 and a sliding contact plate 4, the crushed material is stirred using the means for stirring 21. Subsequently, the fine particle obtained by crushing is buoyant. In addition, a means for grain size classification 8 which is driven by a means for driving 7 is installed on the top of the housing 10 and further, a wind box 11 is mounted between a crushing part and a classification recovery part. Under this design, the fine payticle in a buoyant state is discharged from the housing 10 by an ascending air stream for classification supplied from the wind box 11 and then is classified is in terms of grain size by the impeller of the means for classification 8 from the powder collected from a recovered 9. Thus, it is possible to realize fine particle generation while securing the specific properties of the vertical roller mill.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the invention of a vertical roller mill, and provides a vertical roller mill capable of finely pulverizing without lowering the classification efficiency and further appropriately selecting the degree of fineness. It is what

[0002]

2. Description of the Related Art A vertical roller mill has been widely known from the past, and a plurality of vertical roller parts are processed while supplying materials to be powdered and crushed. It is separated from the housing by the air flow and sent out of the housing. That is, in this vertical roller mill, powdered materials are sequentially selected and sent out, so that the work efficiency is relatively high, and the pulverization efficiency is extremely high when a fine powder of about 200 to 300 mesh is required. It is regarded as one of the excellent and industrially advantageous grinding means.

[0003]

However, in this vertical roller mill, it is almost impossible to make the powder finer than the above, that is, if the particle size becomes smaller than a certain value, it is blown up and discharged. Since it is a material, even if it is repeated and pulverized, further miniaturization hardly progresses.

On the other hand, recent chemical and other technological progress is strongly required to make the material finer, for example, so-called 325 mesh (43μ).
m) Not entirely satisfied (average particle size is about 15 to 25 μm), and it is often necessary to make ultrafine powder of about 5 μm to 10 μm, and further to make it smaller. Therefore, in such a case, it is unavoidable to judge that the limit of the vertical roller mill is exceeded, and what is once pulverized by the vertical roller mill is repeatedly pulverized by another ultra-fine pulverizing equipment. .

However, it is extremely disadvantageous as a factory facility to prepare and set a plurality of types of crushing facilities as described above, and the number of man-hours is also duplicated in the processing work, and further the yield is unavoidable. Obviously, the cost will increase. In particular, the secondary crushing process is understood to be supplementary crushing, the work efficiency is significantly inferior to that of the vertical roller mill, and this secondary crushing determines the product quality. It will be ignored in terms of quality.

[0006]

The present invention has been studied to solve the technical problems in the conventional vertical roller mill as described above, and changed the gas supply for separating and delivering the pulverized material in the vertical roller mill. In addition, it has succeeded in appropriately eliminating the above-mentioned disadvantages by appropriately adjusting this, and is as follows.

(1) In a structure in which a material to be crushed is supplied to a vertical rotary roller at the bottom of a housing and a stirring means is provided to perform a crushing process while stirring, a crusher provided with the vertical rotary roller is provided. The chamber portion is formed in a substantially closed state, a wind box is formed between the crushing chamber of the housing and the separation and collection section, and a supply port for forming a separated rising air flow in the housing is formed in the wind box. A vertical roller mill characterized by being installed.

(2) In the one in which the material to be crushed is supplied to the vertical rotary roller at the bottom of the housing and a stirring means is provided to perform the crushing process while stirring, the crushing provided with the vertical rotary roller An air supply port is formed in the chamber part, and a wind box is formed so as to surround the crushing chamber of the housing and the separation and collection section, and a supply port for forming a large part of the separated rising airflow in the housing in the wind box. A vertical roller mill characterized in that

(3) A duct having a cross-sectional area larger than the ventilation cross-sectional area of the duct provided in the crushing chamber is formed in the wind box, and each of the ducts is provided with a blowing means, and the blowing means has an air flow rate or Arrange each wind power adjustment means,
The vertical roller mill according to the above item 2, wherein the air volume or air force adjusting means is adjusted.

(4) The duct provided in the crushing chamber portion is provided with an air blowing means having a relatively large wind force and a relatively small air volume,
4. The vertical roller mill according to the above item 3, wherein the duct provided in the wind box is provided with an air blowing unit having a relatively small wind force and a relatively large air volume.

[0011]

In the case where the material to be crushed is supplied to the vertical rotary roller at the bottom of the housing and the crushing process is performed by stirring means, the crushing chamber portion provided with the vertical rotary roller is By forming it as a substantially closed state, the fine powder component pulverized in a floating state under an air flow condition in which substantially no upward flow is formed by the rotating action for pulverization by the vertical rotary roller and the stirring action by the stirring means is formed. Form.

As described above, the fine powder component that has formed a floating state is discharged from the housing by the ascending upflow supplied from the air box provided between the crushing chamber of the housing and the separating and collecting section, and is discharged by the bag filter or the like. To be collected.

In the one in which the material to be crushed is supplied to the vertical rotary roller at the bottom of the housing and the crushed material is crushed while being separately collected by the ascending airflow, the crushing position of the housing and the separate collecting section are provided. The air box is formed between the air boxes, and the air supply box is provided in the housing to form the majority of the separated ascending airflow. The air is divided into the air box and the air box, and the amount of supply gas at the crushing position is greatly reduced.

The amount of gas (air) supplied from the wind box into the housing is 75 to 92% of the amount of gas discharged as an updraft from the upper part of the housing, and most of the updraft is above the crushing position. When supplied, the amount of passing gas at the crushing position is generally 8 to 25%.

Due to the reduction of the amount of gas supplied at the crushing position, the particle size of the crushed material separated at the crushing position becomes small, and the residence time of the supplied material in the crushing region becomes long, so that pulverization is also achieved in this respect.

The pressure of the supply gas at the crushing position is 1.2 to the supply gas pressure at the air box part.
It should be increased to about 3.0 times. By increasing the supply gas pressure at the crushing position in this way, it is possible to continuously and stably supply the gas with a small amount of air, and to appropriately obtain the separation and rise of the pulverized fine powder component at the crushing position.

The vertical rotating roller portion and the wind box are each provided with air blowing means, and the air volume or wind force adjusting means is provided in each of these air blowing means, and the air volume or wind force adjusting means is adjusted to perform pulverization. By appropriately changing the ratio of the supply gas amount of the rotating roller portion and the wind box portion located above it, the air pressure of the gas supplied to the crushing position is appropriately increased under the small air volume condition, Increase the efficiency of separation and collection, and variably adjust the particle size range of the pulverized product.

That is, since the amount of gas supplied to the vertical rotary roller portion is relatively small, the particle size of the pulverized material separated and recovered is small, and conversely, the amount of fluid supply to the vertical rotary roller portion is large. By doing so, the particle size of the pulverized material that is separated and recovered becomes large (if the whole amount is supplied to the vertical rotating roller part, it becomes the same as the conventional vertical roller mill), and the particle size of the powder can be freely adjusted. To be elected.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete embodiment of the present invention as described above will be described. The vertical roller mill according to the present invention has a general structural relationship as shown in FIG. The vertical roller 1 and the stirring means 21 are arranged on the vertical shaft 14 rotated by the means 13,
A material to be crushed material 3 is provided on the upper side of the vertical roller 1 so that the material to be crushed is appropriately supplied to the vertical roller 1 portion, and the vertical roller 1 is driven to rotate. The material is crushed between the sliding plate 4 and the stirring means 21.
The stirring is performed by the rotation of the vertical roller 1 and the vertical roller 1 and the stirring means 21 to float the pulverized fine powder.

Further, a classification means 8 rotated by another driving means 7 is provided on the upper part of the housing 10, and is blown up by an air supply as will be described later, and a powder to be separated and collected from a recovery port 9 is obtained. On the other hand, classification processing is performed by the rotary blade 8a of the classification means 8. That is, the rotary vane 8a rotates along the tilt guide 6 formed on the inner surface of the housing 10, and the ascending airflow causes powder particles in the gas that rise along the tilt guide 6 to be inclined.
To give a downward action to the coarse particles in the powder. An oiling pipe 12 is provided for the rotary bearing portion 7a.

That is, the wind box 11 is provided above the inclined expanded portion 10a of the housing 10, and the air from the air supply source supplied to the wind box 11 is blown from the blowing portion 11a provided in the housing 10. It is configured to be blown into the housing 10 to form a blow-up air current to the above-mentioned classification means 8 or the rotary blade 8a portion thereof.

In the structure shown in FIG. 2, in addition to the structure shown in FIG. 1 as described above, a relatively small air blow-in port 2 is provided also for the crushing chamber 20, and the blow-in port 2 also has an upper portion thereof. Air is supplied in the same manner as in the wind box 11 located.

Regarding the air supply to the air inlet 2 and the wind box 11, the air is separately fed by a supply system as shown in FIG. 3 or 4. That is, in FIG. 3, the blower duct by the blower 15 is branched and guided to the air blowing port 2 and the wind box 11, and those branch ducts 16,
Each of 17 has an adjusting means 1 such as a valve or a damper.
8 is provided so that the air volume and the air pressure by the respective branch pipe lines 16 and 17 are appropriately adjusted.

The cross-sectional areas of the air supply ducts 16 and 17 for the air blow-in port 2 and the wind box 11 are different from each other, and the duct 17 for the air blow-in port 2 is disconnected from the cross-sectional area of the duct 16 for the wind box 11. Area is 10
Within the range of 50%, dampers 18 and 18 are provided in the ducts 16 and 17, respectively. That is, the flow rate in the duct 16 is reduced by the damper 18 of the duct 16, so that the wind pressure is also reduced, and the wind pressure supplied by the duct 17 is increased, and the air volume is appropriately selected by the damper 18 of the duct 17. Be done.

Further, in the case of FIG. 4, the air blowing port 2
Pipe lines from the blowers 15 and 15a are separately guided to the wind box 11 and the operating conditions of the blowers 15 and 15a are adjusted appropriately, and the valve 18 is adjusted appropriately to adjust the amount of air blown and the air pressure. Made to adjust.

That is, in the case of supplying by the same blower as shown in FIG. 3, even if the air volume can be adjusted by opening / closing adjustment of the dampers 18, 18, it is difficult to greatly change the air pressure. In particular, if it is not properly obtained on the duct 17 side, it will be difficult to obtain effective separation when pulverizing ore or the like at the pulverizing position.
When the separate blowers 15 and 15a are used as shown in FIG. 4, the air volume is small and the air pressure can be increased, and the air pressure in the duct 17 exceeds twice the air pressure in the duct 16. Such conditions are effectively formed to effectively separate and raise pulverized fine particles having a high specific gravity.

That is, the amount of air supplied to the blow-in port 2 determines the degree of separation of the crushed material from the crushing chamber 20 by the vertical roller 1, and when the amount of air is low, the separated and rising powder particles become finer, which is Under high conditions, coarse particles are also blown up. In other words, the pulverized material that separates and rises becomes finer, so that the pulverized material obtained from the recovery port 9 becomes finer particles, and the relatively coarse pulverized material remains in the pulverizing chamber 20 which is the vertical roller 1 part and is continuously subjected to the pulverizing effect. Be miniaturized.

Regarding the supply of air from the ducts 16 and 17, the rotational drive of either or both of the blowers 15 and 15a is stopped, and the ducts 16 and 17 are appropriately formed in either or both of them. As a matter of course, the rising air flow may be formed in the housing in the same manner as described above by opening the outside air inlet and applying a suction force to the recovery port 9 so that the inside of the housing 10 is appropriately set to a negative pressure condition. .

In any case, the amount of air required to obtain the pulverized material recovery from the recovery port 9 is about the same, but according to the concrete operation results, about 85% of the required air amount is about 1%.
In the case of blowing from No. 1, fine powder with an average particle size of 8 to 15 μm can be obtained by selecting the object to be crushed, and the blowing amount from this wind box is further increased to 88 to 90%.
By setting the degree to be about, it becomes possible to obtain ultrafine powder having an average particle size of 10 μm or less.

In the above-mentioned FIG. 1, the fine particles to be floated are floated by the rotation of the vertical rotary roller 1 and the stirring means 21 under the condition that the upward flow is not substantially formed. It will be in the state. On the other hand, in the case shown in FIG. 2 and below, some coarser powder is mixed depending on the amount of air blown from the air blowing port 2,
Compared to the case where the entire amount of the ascending air current is supplied to the crushing chamber 20, the powder is remarkably finely divided.

Under the conditions shown in FIG. 1 or FIG. 2 in which the positive pressure air supply to the crushing chamber 20 is cut off, ultrafine powder having an average particle size of 8 μm or less can be obtained.

[0032]

According to the present invention as described above, it is possible to appropriately obtain the ultrafine powder while ensuring the characteristics of the vertical roller mill, and to appropriately select the degree of the obtained fine powder. It is an invention that has a great effect industrially.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing one form of a vertical roller mill according to the present invention.

FIG. 2 is a partially cutaway side view showing a second mode of the vertical roller mill according to the present invention.

FIG. 3 is an explanatory view showing an example of an air supply system for the vertical roller mill shown in FIG. 2 of the present invention.

FIG. 4 is an explanatory view similar to FIG. 3, showing another example thereof.

[Explanation of symbols]

1 Vertical roller 2 Air inlet 3 Materials to be crushed 4 sliding plate 6 Tilt guide 7 Drive means 8 classification means 8a rotary blade 9 Collection port 10 housing 10a Inclined diameter expansion part 11 wind box 12 Lubrication line 13 Drive means 14 Vertical axis 15 blower 15a blower 16 Branch pipes (ducts) 17 Branch pipes (ducts) 18 Pressure adjusting means 20 Grinding chamber 21 stirring means

Claims (4)

[Claims] 1. A crushing chamber provided with a vertical rotating roller in which a material to be crushed is supplied to a vertical rotating roller at the bottom of a housing and a stirring means is provided for crushing while stirring. The portion is formed as a substantially closed state, a wind box is formed between the crushing chamber of the housing and the separation and collection section, and a supply port for forming a separated rising airflow in the housing is arranged in the wind box. A vertical roller mill characterized by being installed. 2. A crushing chamber provided with the vertical rotary roller, wherein a material to be crushed is supplied to the vertical rotary roller at the bottom of the housing and a stirring means is provided to perform the crushing process while stirring. An air supply port is formed in a portion of the housing, and a wind box is formed between the crushing chamber of the housing and the separation / recovery section, and the air box has a supply port for forming a large part of the separated rising airflow in the housing. A vertical roller mill characterized by being installed. 3. A duct having a cross-sectional area larger than the ventilation cross-sectional area of the duct provided in the grinding chamber portion is formed in the wind box,
The blower means is provided in each of the ducts, the air volume or the wind force adjusting means is arranged in each of the blower means, and the air volume or the wind force adjusting means is adjusted and operated. Vertical roller mill. 4. A duct provided in the crushing chamber portion is provided with an air blowing means having a relatively large wind force and a relatively small air volume, and a duct provided in the wind box has a relatively small wind force and a relatively large air volume. The vertical roller mill according to claim 3, further comprising: