JPS59102449A - Shaft type mill - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 A classification device 6 is provided in the upper part of the casing 2, and is composed of a rotating vertical shaft 8 suspended inside the casing 2 and a blade 30 mounted on the rotating vertical shaft 8. Hot gas, etc. is classified into fine powder and coarse powder by the centrifugal force of the rotating blades 30 in this classifier 6, and the fine powder is sent to the fine powder take-out pipe 7, and the coarse powder is sent to the radial direction of the classifier 6. guided by.

However, in the conventional vertical mill 1 configured in this way, the pulverized material is crushed by the crushing section 3 provided at the inner bottom of the casing 2 using a fluid such as hot gas to classify the crushed material at the top of the casing 2. Furthermore, the coarse powder classified by the blades 30 is not returned to the crushing section 3, but rejoins the crushed material being transferred and is repeatedly sent to the classification device 6. Since the coarse powder is not re-pulverized, there are disadvantages such as a decrease in classification efficiency, a decrease in pulverization efficiency, and an increase in pressure loss.

Therefore, an object of the present invention is to eliminate such conventional drawbacks by arranging the crushing section at the top of the classifier, so that the crushed material crushed in the crushing section can be transferred to the classifier simply by falling downward. In addition, a classification device is installed that uses two forces: fluid resistance due to vortex flow and centrifugal force due to the rotation of a rotating plate. It is an object of the present invention to provide a vertical mill that improves classification efficiency and crushing efficiency by returning the raw materials to the crushing section using a transporter such as the above.

According to this invention, a vertical mill is a vertical mill that crushes and classifies cement raw materials, coal, etc., and is configured by separately providing a classification device at the bottom of a crushing section that has a crushing roller and a rotating 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 the same or equivalent parts as in 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 rotate horizontally within the crushing unit casing 2a, and a plurality of crushing rollers 3b provided to roll in contact with the upper surface of the rotary table 3a.
(hereinafter abbreviated as roller), a drive shaft 3c and a drive device 3d for driving the rotary table 3a, and a crushing unit hopper 2b attached to the lower part of the crushing unit casing 2a.
It consists of The rollers 3b are arranged so as to be inclined inward, and feed the raw material 40 introduced from the raw material supply chute 5 fixed to the crusher casing 2a into the approximately central part of the rotary table 3a between the rotary table 3a and the rollers 3b. The rotary table 3a is configured to pulverize the pulverized material 41 by relative movement with the rotary table 3a, and scatter the pulverized material 41 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. The end of the raw material transfer pipe 4 provided at the lower part of the crusher hopper 2b is connected to the classifier casing 2c.
The crushed material 41 is fixed to the center hole at the top of the crushing part 3.
It is designed so that it falls from there to the classification device 6. The classifier 6 is provided approximately at the center of the casing 2 through a classifier casing 2c having a fluid inlet 14 and forming a vortex chamber, and a raw material transfer pipe 4 attached to a central hole at the top of the classifier casing 2c. a rotating vertical shaft 8, a rotating plate 9 mounted on the lower end of the rotating vertical shaft 8, and a rotating vertical shaft 8 above the rotating plate 9.
A cylindrical collision plate 11 is formed between the rotary plate 9 and the dispersion plate 10 to direct the fluid from the fluid inlet 14. A guide vane 12 that leads to the classification chamber 20, a coarse powder cone 2d attached to the lower part of the classifier casing 2c, and an opening that passes through the coarse powder cone 2d and is attached to the lower surface of the rotary plate 9 adjacent to the coarse powder cone 2d. and a 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 rotating vertical shaft 8, and collects the crushed material 41 falling from the raw material transfer pipe 4.
The particles are scattered in the radial direction and collided 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. They are mounted on shafts so as to be substantially coincident with each other, and are configured so that the crushed material 41 is classified and dispersed by rotation, and the fine powder 43 after classification is sent to the fine powder discharge pipe 7 through 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 angle thereof can be freely adjusted by a lever 13 on the upper part of the classifier casing 2c. In addition, in order to adjust the amount of fluid sent into the classifier casing 2c, a secondary fluid intake port 1 is provided in a tangential direction at a position approximately symmetrical to the fluid inlet port 14.
5 may be provided. 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 and a product collector is connected to the fine powder discharge pipe 7, and this product line is started. to create negative pressure inside the casing 2. Next, the rotating vertical shaft 8, the rotating plate 9, and the dispersing plate 1 are driven by the driving device 8a.
At the same time, the rotary table 3a and rollers 3b in the crushing section 3 are rotated via the drive shaft 3c by the driving device 3d, thereby starting the operation of the vertical mill 1. Rotary table 3 via raw material supply chute 5
When the raw material 40 is supplied to the upper surface of the rotary table 3a, the raw material 40 is crushed into particles or powder between the rotary table 3a and the rollers 3b, and is scattered in the outer circumferential direction by the centrifugal force of the rotary table 3a. This crushed material 41 is transferred from the gap 3e to the crushing section hopper 2.
b, and is sent to the classification device 6 through the raw material transfer pipe 4 provided at the lower part of the crusher 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, fluids such as air, cooling air, hot gas, etc. sent from the fluid inlet 14 form a vortex by the guide vanes 12 set at an appropriate angle and merge 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 this fluid intake port 15. The fluid forming the vortex and containing the crushed material 41 is strengthened by the rotation of the rotary plate 9, and is simultaneously subjected to two contradictory forces: outward centrifugal force and inward fluid resistance. If the diameter of the pulverized material 41 that is in balance between these two forces is called the classification point, the pulverized material 41 below the classification point, that is, the fine powder 43, will have more inward fluid resistance than the outward centrifugal force. becomes larger, moves toward the center on the fluid, and is guided from the hole 9b of the rotary plate 9 through the fine powder extraction pipe 7 to the product line. On the other hand, the pulverized material 41 having a diameter equal to or larger than the classification point, that is, the coarse powder 42, has a centrifugal force greater than the inward fluid resistance, and the conical coarse powder cone 2d falls while flowing along the inside of the guide vane 12. . If a tertiary fluid intake port 16 is provided inside the coarse powder cone 2d, the fluid fed through the fluid intake port 16 will adhere to the coarse powder and mix into the coarse powder cone 2d. The crushed material 41 can be dispersed and returned to the classification chamber 20 for reclassification. The coarse powder 42 classified in this way is passed through the lower end opening of the coarse powder cone 2d to the vertical mill 1.
The coarse powder 42 is discharged outside, is lifted up to the raw material supply chute 5 by a transport device such as a bucket elevator (not shown), is mixed with the raw material 40, is re-pulverized as described above, or is the coarse powder 42 The product is sent to another product line.

Further, a vertical mill 1 constructed according to the present invention as described above is also provided.
If the size of the classification chamber 20 is also increased, 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 rotary 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 as follows:
Although it is similar to that shown in Fig. 3, the turbulence of the eddy current is reduced by providing the eddy current adjustment piece 22, and the effect of displacement fluctuation of the longitudinal component velocity of the eddy current is eliminated by further providing the partition plate 21. I can do it. 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. Also,
The number of classification chambers 20 divided by the partition plates 21 may be determined by 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.

In addition, in this embodiment, the central axis of the crushing section 3 and the classifier 6
However, as shown in FIG. 8, the center axes of the crushing unit 3 and the classifying device 6 can be shifted from each other by using an oblique cone-shaped object in the crushing unit hopper 2b. I can do it. Furthermore, in the example described above, the drive shaft 3c for driving the rotary table 3a of the crushing section 3 is installed below the rotary table 3a, but as shown in FIG. Of course, the same effect can be obtained even if the rotary table 3a is mounted on the lower end of the drive shaft 3c which passes through the center of the top and hangs down. 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. Since the crushing section and classifier are separated from each other, they are hardly affected by each other. This enables highly efficient, extremely economical, and stable operation. Also,
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, Fig. 3 is a sectional view taken along line A-A in Fig. 1, and Fig. 4. 5 is a schematic diagram of another embodiment of the vertical mill according to the present invention; FIGS. 5, 6, and 7 are plan views showing various attachment states of the rotary plate and the vortex adjustment piece; and FIGS. 8 and 9 are diagrams of the present invention. It is a schematic explanatory drawing of another Example of the vertical mill according to. In the figure, 1: Vertical mill, 2a: Crushing section casing, 2b: Crushing section hopper, 2c: Classifier casing, 2
d: Coarse powder cone, 3: Grinding section, 6: Classifier, 7: Fine powder discharge pipe, 8: Rotating vertical shaft, 9: Rotating plate, 10: Dispersion plate, 1
1: Collision plate, 12: Guide vane, 20: Classification chamber, 21
: Partition plate, 22: Eddy current adjustment piece, 40: Raw material, 41: Pulverized product, 42: Coarse powder, 43: Fine powder.

Claims (8)

[Claims] 1. A vertical mill that crushes and classifies cement raw materials, clinker, coal, etc., and has a separate classification device installed below a crushing section that has crushing rollers and a rotating table. 2. The classifier includes a classifier casing having a fluid inlet and forming a vortex-shaped chamber, a rotating vertical shaft hanging down through a raw material transfer pipe provided in a central hole at the top of the classifier casing.
A rotary plate mounted on the lower end of a rotating vertical shaft and having a hole for taking out fine powder; a dispersion plate mounted on the rotating vertical shaft above the rotating plate; a cylindrical 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; It consists of a fine powder discharge pipe that passes through the cone and is installed so that its opening is adjacent to the lower surface of the rotary plate.The crushed material from the raw material inlet is guided into the classification chamber by a dispersion plate and a collision plate, and is then passed through a guide vane. It merges with the fluid converted into a vortex flow, performs dispersion and classification by rotating the rotary plate, takes out the fine powder from the fine powder discharge pipe through the fine powder extraction hole, and drops the coarse powder into the coarse powder cone to be discharged to the outside. The vertical mill according to claim 1, characterized in that the mill is configured to discharge. 3. A vertical mill according to claim 1 or 2, characterized in that a plurality of eddy current adjusting pieces are attached to the rotary plate. 4. 4. The vertical mill according to claim 3, wherein a partition plate is horizontally attached to the eddy current adjustment piece to divide the classification chamber into a plurality of sections. 5. Claims 2 to 4, characterized in that a secondary fluid intake port is provided in a tangential direction of the classifier casing.
The vertical mill according to any one of the items. 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. 2. The vertical mill according to claim 1, wherein the classification device uses one of a starter band air separator or a cyclone air separator. 8. 8. The vertical mill according to any one of claims 1 to 7, wherein the coarse powder after classification is transported to a crushing section by a transporter such as a bucket elevator to be re-pulverized.