JPH0325226B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vertical mill equipped with a classifier.

In general, in a vertical mill that crushes cement raw materials, clinker, coal, etc., in order to classify and take out the crushed material crushed by a crushing part such as a roller to a desired particle size or fineness, conventionally, for example, the attached drawing A vertical mill as shown in FIG. 1 is used. The vertical mill 1 as shown in FIG. It is designed to be transferred to the top of the screen. At the top of the casing 2, there is a classification device 6 comprising a rotating vertical shaft 8 suspended inside the casing 2 and a blade 30 mounted on the rotating vertical shaft 8.
is provided, and the transported pulverized material and hot gas etc. are passed through the rotating blades 3 in this classification device 6.
The powder is classified into fine powder and coarse powder by centrifugal force of 0, the fine powder is sent to the fine powder take-out tube 7, and the coarse powder is guided in the radial direction of the classifier 6.

However, in the conventional vertical mill 1 configured in this way, the crushed material is crushed by the crushing section 3 provided at the inner bottom of the casing 2 using a fluid such as hot gas. A large amount of power is required to transfer the material to the classification device 6, and the blade 3
The coarse powder classified by 0 is not returned to the crushing section 3, but instead joins the crushed material being transported and sent to the classification device 6, which is repeated, and the coarse powder is not re-pulverized, resulting in a reduction in classification efficiency. There are drawbacks such as a decrease in grinding efficiency and an increase in pressure loss.

Therefore, an object of the present invention is to eliminate the drawbacks of the conventional method by arranging the crushing section at the upper part of the classifier, so that the crushed material crushed in the crushing section can be classified by simply dropping it downward. In addition, a classification device is installed to classify the coarse powder using two forces: fluid resistance due to vortex flow and centrifugal force due to the rotation of the rotary plate. It is an object of the present invention to provide a vertical mill in which classification efficiency and grinding efficiency are improved by returning the waste to the grinding section using a transporter such as a bucket elevator after discharging the waste.

According to this invention, the vertical mill is a vertical mill that crushes and classifies cement raw materials, coal, etc.
A classification device is separately provided at the bottom of a crushing section having a crushing roller and a rotary table.

Other objects, features and advantages of the present invention will become apparent from the detailed description taken in conjunction with the following drawings.

FIGS. 2 and 3 of the drawings show an embodiment of a vertical mill according to the present invention, and parts corresponding to the conventional device shown in FIG. 1 described above are given the same reference numerals. It is being As shown in the figure, the vertical mill 1 of the present invention consists of a crushing section 3 and a classifier 6 attached to the lower part of the crushing section 3. The casing 2 includes a cylindrical crushing part casing 2a in the crushing part 3 and a conical crushing part hopper 2b provided at the lower part thereof, and a spiral cylindrical classifier casing 2c in the classifier 6 and a conical part casing 2a in the lower part thereof. It consists of 2d coarse corn. The crushing unit 3 includes a rotary table 3a provided to be horizontally rotationally driven within the crushing unit casing 2a.
, a plurality of crushing rollers 3b (hereinafter abbreviated as rollers) provided to roll in contact with the upper surface of the rotary table 3a, a drive shaft 3c and a drive device 3d for driving the rotary table 3a, It consists of a crushing part hopper 2b attached to the lower part of a part casing 2a. The rollers 3b are arranged to be inclined inward, and the raw material 40 is fed from the raw material supply chute 5 fixed to the crusher casing 2a to approximately the center of the rotary table 3a.
is pulverized by the relative movement between the rotary table 3a and the rollers 3b, and the pulverized material 41 is scattered in the radial direction by the centrifugal force of the rotary table 3a. A gap 3e is formed between the inner wall of the crusher casing 2a and the rotary table 3a, and the crushed material 41 falls into the crusher hopper 2b from this gap 3e. A raw material transfer pipe 4 provided at the bottom of the crushing part hopper 2b
The lower end of the crusher casing 2c is fixed to the center hole at the top of the classifier casing 2c, so that the crushed material 41 falls from the crusher 3 into the classifier 6. The classifier 6 includes a classifier casing 2c having a fluid inlet 14 and forming a vortex chamber, and a classifier casing 2c.
A rotating vertical shaft 8 is provided approximately at the center of the casing 2 through a raw material transfer pipe 4 attached to a central hole at the top of the casing 2, and a rotating plate 9 is mounted on the lower end of the rotating vertical shaft 8.
, a dispersion plate 10 that is mounted on the rotating vertical shaft 8 above the rotary plate 9, a cylindrical collision plate 11 provided at a distance on the outer periphery of the dispersion plate 10, and a fluid from the fluid inlet 14 that rotates. A guide vane 12 leading to the classification chamber 20 formed between the plate 9 and the dispersion plate 10, a coarse powder cone 2d attached to the lower part of the classifier casing 2c, and a rotary plate 9 passing through the coarse powder cone 2d. A fine powder discharge pipe 7 is installed so that the opening is adjacent to the lower surface of the fine powder discharge pipe 7. The rotating vertical shaft 8 is connected to a drive device 8a provided outside the casing 2. The dispersion plate 10 rotates together with the rotary vertical shaft 8 to collect the crushed material 4 falling from the raw material transfer pipe 4.
1 is scattered in the radial direction and collides with the collision plate 12. As clearly shown in FIG. 3, the rotating plate 9 has a hole 9b of an appropriate size, and connects the lower end of the rotating vertical shaft 8 to the lower end surface of the classifier casing 2c via a plurality of spokes 9a. The shafts are mounted so that they are almost coincident with each other, and by rotating, the crushed material 41 is classified and dispersed, and the fine powder 43 after classification is
The fine powder is sent to the fine powder discharge pipe 7 from the hole 9b. A large number of guide vanes 12 are provided at equal intervals on the same axis as the rotating vertical shaft 8 and the rotating plate 9, and the guide vanes 12 are arranged at equal intervals on the same axis as the rotating vertical shaft 8 and the rotating plate 9.
3 allows the angle to be adjusted freely. Further, in order to adjust the amount of fluid sent into the classifier casing 2c, a secondary fluid intake port 15 may be provided in a tangential direction at a position substantially symmetrical to the fluid inlet 14. Furthermore, in order to improve classification efficiency, a tertiary fluid intake port 16 can also be attached to the coarse powder cone 2d.

In the vertical mill 1 of the present invention configured as described above, first, a product line (not shown) such as an exhaust fan or a product collector is connected to the fine powder discharge pipe 7.
This product line is started to create a negative pressure inside the casing 2. Next, the rotating vertical shaft 8, rotating plate 9, and dispersing plate 10 are rotated together by driving the driving device 8a, and at the same time, the rotating table 3a and rollers 3b in the crushing section 3 are rotated via the driving shaft 3c by driving the driving device 3d. Then, the vertical mill 1 is started to operate. When the raw material 40 is supplied to the upper surface of the rotary table 3a via the raw material supply chute 5,
The raw material 40 is pulverized into granules or powder between the rotary table 3a and the rollers 3b.
It is scattered in the outer circumferential direction by the centrifugal force. This crushed material 41 falls into the crushing part hopper 2b from the gap 3e, and is sent to the classifier 6 through the raw material transfer pipe 4 provided at the lower part of the crushing part hopper 2b. The crushed material 41 introduced from the raw material transfer pipe 4 is dispersed by the rotation of the dispersion plate 10, collides with the collision plate 11, and falls into the classification chamber 20. In the classification chamber 20, fluid such as air, cooling air, hot gas, etc. sent from the fluid inlet 14 forms a vortex by the guide vanes 12 set at an appropriate angle and merges with the crushed material 41. When the secondary fluid intake port 15 is provided, the amount of classified fluid in the classification chamber 20 can be adjusted by replenishing fluid such as air from the fluid intake port 15. Forming a vortex and crushing the material 4
The rotating airflow of the fluid containing 1 is strengthened by the rotation of the rotary plate 9, and the fluid containing 1 is simultaneously subjected to two contradictory forces: outward centrifugal force and inward fluid resistance. A crushed object 4 that is in equilibrium between these two forces
If the diameter of 1 is called the classification point, the crushed material 41 below the classification point, that is, the fine powder 43, has a larger inward fluid resistance than the outward centrifugal force, moves toward the center on the fluid, and moves toward the center of the rotating plate. The fine powder is led to the product line through the hole 9b of 9 through the fine powder extraction pipe 7. On the other hand, pulverized material 41 having a diameter equal to or larger than the classification point, that is, coarse powder 42
The centrifugal force becomes greater than the inward fluid resistance, and the conical coarse powder cone 2d falls while flowing along the inside of the guide vane 12. 2d coarse corn
If a tertiary fluid intake port 16 is provided inside the fluid intake port 16, the fluid fed from the fluid intake port 16 adheres to the coarse powder and causes the coarse powder cone 2d to
The crushed material 41 below the classification point mixed therein can be dispersed and returned to the classification chamber 20 for re-classification.
The coarse powder 42 classified in this way is the coarse powder corn 2.
The raw material 4 is discharged from the lower end opening of the vertical mill 1 and lifted to the raw material supply chute 5 by a transport device (not shown) such as a bucket elevator.
0 and re-ground as described above, or alternatively, this coarse powder 42 is sent as a product to another product line.

Furthermore, if the vertical mill 1 configured according to the present invention is also increased in size, it will be difficult to generate an ideal vortex in the classification chamber 20, and there is a possibility that the classification efficiency will decrease. .

Therefore, FIG. 4 shows another embodiment of the invention which further improves this point. As shown in the figure, this vertical mill 1 has a plurality of vortex flow adjusting pieces 22 installed between the rotating plate 9 and the dispersion plate 10 of the classifier 6 shown in FIGS. 2 and 3, and further vortex flow adjustment. The classification chamber 20 is divided into a plurality of chambers by attaching a partition plate 21 to the piece 22.

The classification principle of the vertical mill 1 configured in this way is the same as that shown in FIGS. By providing 21,
The influence of displacement fluctuations in the vertical velocity of the vortex can be eliminated. As a result, even in the large vertical mill 1, the classification accuracy can be improved without causing disturbance in the vortex flow. The vortex adjustment piece 22 is placed on the rotary plate 9 as shown in FIGS. It is placed at a selected position and angle. Further, the number of classification chambers 20 divided by the partition plates 21 may be determined based on the size of the classification chambers 20 in consideration of the classification point and classification accuracy. It is economical because sufficient classification accuracy can be obtained without excessively increasing the size of the classification device 6 of the mold mill 1.

Further, in this embodiment, the central axis of the crushing section 3 and the central axis of the classifier 6 are arranged coaxially, but as shown in FIG. 8, the crushing section hopper 2b
The center axes of the crushing section 3 and the classifying device 6 can be shifted from each other by using an oblique cone-shaped device. Furthermore, in the example described above, the drive shaft 3c for driving the rotary table 3a of the crushing section 3 is the rotary table 3a.
As shown in FIG. 9, a rotary table 3 is attached to the lower end of a drive shaft 3c that passes through the center of the top of the crusher casing 2a and hangs down.
Of course, the same effect can be obtained even if a is mounted on a shaft. Further, the classification device 6 is not limited to the one in the embodiment described above, and a classification device such as a sturtevant air separator or a cyclone air separator can also be used.

As described above, according to the present invention, by arranging the crushing section at the upper part of the classifier, the entire amount of crushed materials is sent to the classifier with a simple structure that allows the crushed materials crushed in the crushing section to fall downward. This eliminates the need for a complicated mechanism or large amount of power for the transfer means unlike conventional equipment, and since the crushing section and classification device are separated, they are hardly affected by each other. This enables highly efficient, extremely economical, and stable operation of the device.
Further, the coarse powder obtained after classification can be recovered as a product without being re-pulverized, which has the advantage of increasing the range of applications.

[Brief explanation of the drawing]

FIG. 1 is a schematic illustration of a conventional vertical mill, FIG. 2 is a schematic illustration of a vertical mill according to the present invention, and FIG. 3 is a schematic illustration of a vertical mill according to the present invention.
The figure is a cross-sectional view taken along the line A-A in Figure 2, Figure 4 is a schematic diagram of another embodiment of the vertical mill according to the present invention, and Figures 5, 6, and 7 are a cross-sectional view of the rotary plate and the vortex adjustment piece. FIGS. 8 and 9 are plan views showing various mounting states, and are schematic illustrations of another embodiment of the vertical mill according to the present invention. In the figure, 1: vertical mill, 2a: crushing part casing, 2b: crushing part hopper, 2c: classifier casing, 2d: coarse powder cone, 3: crushing part, 6: classifier, 7: fine powder discharge pipe, 8: Rotating vertical shaft, 9: Rotating plate, 10: Dispersion plate, 11: Collision plate, 12: Guide vane, 20: Classification chamber, 21: Partition plate, 22: Vortex flow adjustment piece, 40: Raw material, 41: Pulverized material , 42: Coarse powder, 43: Fine powder.

Claims (1)

[Scope of Claims] 1. A vertical mill for crushing and classifying cement raw materials, clinker, coal, etc., in which a classifying device is separately provided at the bottom of a crushing section having a crushing roller and a rotating table. 2 The classification device consists of a classification device casing having a fluid inlet and forming an overshaped chamber, a rotating vertical shaft hanging down through a raw material transfer pipe provided in a central hole at the top of the classifying device casing, and a rotating vertical shaft. A rotary plate is mounted on a shaft at the lower end and has a hole for taking out fine powder, a dispersion plate is mounted on a vertical rotating shaft above the rotary plate, and a cylindrical plate is provided at a distance on the outer periphery of the dispersion plate. A collision plate, a guide vane that guides the fluid from the fluid inlet to the classification chamber formed between the rotating plate and the dispersion plate, a coarse powder cone attached to the lower part of the classifier casing, and a guide vane that penetrates the coarse powder cone. It consists of a fine powder discharge pipe installed with its opening adjacent to the bottom surface of a rotating plate, and the crushed material from the raw material inlet is guided into the classification chamber by a dispersion plate and a collision plate, and is converted into a vortex by a guide vane. Dispersion and classification are performed by the rotation of the rotary plate, the fine powder is taken out from the fine powder discharge pipe through the fine powder extraction hole, and the coarse powder is dropped into the coarse powder cone and discharged to the outside. A vertical mill according to claim 1, characterized in that the vertical mill comprises: 3. The vertical mill according to claim 1 or 2, characterized in that a plurality of vortex adjustment pieces are attached to the rotary plate. 4. The vertical mill according to claim 3, characterized in that a partition plate is horizontally attached to the vortex adjustment piece to divide the classification chamber into a plurality of sections. 5. The vertical mill according to any one of claims 2 to 4, characterized in that a secondary fluid intake port is provided in a tangential direction of the classifier casing. 6. The vertical mill according to any one of claims 2 to 5, characterized in that the coarse powder cone is provided with a tertiary fluid intake port. 7. The vertical mill according to claim 1, wherein the classification device uses either a Sturte band air separator or a cyclone air separator. 8. The method according to any one of claims 1 to 7, characterized in that the coarse powder after classification is transported to a crushing section by a transporter such as a bucket elevator and re-pulverized. Vertical mill.