JPS59102450A - 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. The hot gas, etc. is classified into fine powder and coarse powder by the centrifugal force of the rotating blades 30 in this classifier 6, 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 4. guided by.

However, in the conventional vertical mill 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.
The coarse powder classified by the blades 30 is transferred to the crushing section 3, which requires a large amount of power.
As a result, the coarse powder is not returned to the pulverized powder, but is re-merged with the pulverized material being transported and sent to the classifier 6, which causes a decrease in classification efficiency, a decrease in pulverization efficiency, and an increase in pressure loss because the coarse powder is not re-pulverized. There are some drawbacks such as:

Therefore, an object of the present invention is to provide a crushing section in the upper part of the casing and a classification device integrated with the crushing section in the lower part of the casing, in order to eliminate such drawbacks in the conventional method. The pulverized material can be transferred to the classification device by simply dropping it downward, and the classified coarse powder is discharged outside the vertical mill and then returned to the pulverization section using a transport device such as a bucket elevator, thereby improving classification efficiency. The object of the present invention is to provide a vertical mill that improves grinding efficiency.

According to this invention, the vertical mill is used to process cement raw materials and clinker. A vertical mill for pulverizing and classifying coal, etc. comprises a pulverizing section having a pulverizing roller and a rotary table, and a classification device disposed at the bottom of the pulverizing section. a spiral-shaped classifier casing, a rotating vertical shaft provided approximately at the center of the classifier casing, a rotary plate mounted on the rotating vertical shaft, and a rotary plate mounted at a distance on the outer periphery of the classifier casing. It consists of a plurality of guide vanes, a coarse powder cone attached to the bottom of the classifier casing, and a fine powder discharge pipe installed at the bottom of the rotating plate. It is configured to classify by rotation.

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

FIG. 2 shows an embodiment of a vertical mill according to the present invention, and the same or equivalent parts as those of the conventional device shown in FIG. 1 described above are given the same reference numerals. The vertical mill 1 of the present invention includes a crushing section 3 and a classifier 6 integrally provided. 3a, and a plurality of crushing rollers 3b (hereinafter abbreviated as rollers) provided so as to roll in contact with the upper surface of the rotary table 3a. The rollers 3b are arranged to be inclined inward, and pass through the center of the top of the crusher casing 2a from the raw material supply chute 5 fixed to the rotary table, and transfer the raw material 40 fed into the approximately central portion of the rotary table 3a to the rotary table. The rotary table 3a is pulverized by the relative movement of the roller 3b, and the pulverized material 41 is scattered in the radial direction by the centrifugal force of the rotary table 3a. Crushing part casing 2a
There is a gap 3e between the inner wall of the rotary table 3a and the outer peripheral edge of the rotary table 3a.
is formed, and the crushed material 41 is dropped from this gap 3e to the classification device 6 provided at the lower part of the casing 2.
It is designed to be transferred to The classifier 6 includes a classifier casing 2c that forms a spiral chamber and is fixed to the outer peripheral edge of the flange portion of the crusher casing 2a, and a hollow space that is provided coaxially with a drive shaft 3c at approximately the center of the classifier casing 2a. A rotating vertical shaft 8, a dispersing plate 1O mounted on the upper end of the rotating vertical shaft 8, a classifier casing on the outer periphery of the dispersing plate 10, a collision plate 11 provided integrally with the inner wall 2c, a classifier casing, A rotating plate 7 is mounted on a rotating vertical shaft 8 so as to substantially coincide with the lower end surface of 2c, and a classification chamber 30 is formed between the rotating plate 7 and the dispersion plate 10 for transporting fluid from the fluid inlet 14.
a guide vane 12 that guides the flow, an oblique cone-shaped coarse powder cone 2d attached to the lower part of the classifier casing 20, and a coarse powder cone 2d that passes through the coarse powder cone 2d and is attached so that its opening is adjacent to the lower surface of the rotary plate 9. It consists of a fine powder discharge pipe 7. Rotating vertical shaft 8 and drive shaft 3c of rotary table 3a
It has a double-shaft structure with a rotating vertical shaft 8 on the outer shaft and a drive shaft 3c on the inner shaft, which are connected to drive devices 8a and 3d provided outside the casing 2 and operated individually. It looks like this. The dispersion plate 10 rotates together with the rotating vertical shaft 8, and collects the crushed material 41 falling from the gap 3e of the crushing section 3.
The particles are scattered in the radial direction and collided with the collision plate 11. As clearly shown in FIG. 3, the rotary plate 7 has a hole 9b of an appropriate size, and is connected to the rotary vertical shaft 8 through a plurality of spokes 9a, substantially coinciding with the lower end surface of the classifier casing 3c. The shaft is mounted so that the pulverized material 41 is classified and dispersed by rotation, and the classified fine powder 43 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 a circumference concentric with the rotary shaft 8 and the rotary plate 7, and their angles can be freely adjusted by a lever 13 on the upper part of the classifier casing 2c. Further, in order to adjust the amount of fluid sent into the classifier casing 2c, the primary fluid intake port 13 may be provided in a tangential direction at a position substantially symmetrical to the fluid inlet port 14. Furthermore, in order to improve classification efficiency, a tertiary fluid intake port 16 can 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 and the product line is started. to create negative pressure inside the casing. 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 tape 3a and roller 3b in the crushing section 3 are rotated through the driving shaft 3c by driving the driving device 3a. Then, the vertical mill 1 is started to operate. The raw material 40 is pulverized into particles or powder through the raw material supply chute 5 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 passed through the gap 3e to the classification device 6.
The particles fall onto the dispersion plate 10, are dispersed by the rotation of the dispersion plate 10, collide with the collision plate 11, and then fall 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 pulverized material 41. If 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 through the 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 and moves toward the center on the fluid, rotating plate 9
The fine powder is guided from the hole 9b through the fine powder take-out pipe 7 to the product line. On the other hand, the pulverized material 41, that is, the coarse powder 42 having a diameter equal to or larger than the classification point, is subjected to a centrifugal force greater than the inward fluid resistance, and falls into the oblique conical coarse powder cone 2d while flowing along the inside of the guide vane 12. do. 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 manner is discharged from the lower end opening of the coarse cone 2d to the outside of the vertical mill 1.
The raw material feed chute 5 may be sent as a product to another product line, or may be sent to a raw material feed chute 5 by a transport device such as a packet elevator.
The raw material 40 is mixed with the raw material 4O and re-pulverized as described above.

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 has a plurality of vortex adjustment pieces 22 installed between the rotary plate 7 and the dispersion plate 10 of the classifier 6 shown in FIGS. A partition plate 21 is attached to 22 to divide the classification chamber 20 into a plurality of chambers.

The classification principle of the vertical mill 1 with grooves in this way is the second,
Although it is similar to that shown in Fig. 3, the turbulence of the eddy current is reduced by providing the eddy current adjusting 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 31. Can be done. As a result, even in the large vertical mill 1, the classification accuracy can be improved without causing disturbance in the vortex flow. This eddy current adjusting piece 22 is placed on the rotary plate 7 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. Sufficient classification accuracy can be obtained without excessively increasing the size of the classification device.

Further, FIG. 8 shows another embodiment according to the present invention. As shown in the figure, in this vertical mill 1, a rotary table 3a of a crushing section 3 and a rotary plate 9 of a classifier 4 are mounted on a single rotary vertical shaft 50. The classification chamber 20 is formed in the classification chamber 20. The crushed material 41 crushed in the crushing section 3 is scattered in the radial direction by the rotation of the rotary table 3a, collides with the inner wall of the crushing section casing 3a, falls, and is sent to the classification chamber together with the fluid. In the vertical mill 1 constructed in this way, the principle of crushing and classification is the same as that shown in Figs. 2 to 4, but the rotary table 3a and the rotary plate 7 rotate together. Because of this, it is not possible to increase the rotation speed, resulting in a relatively rough product. Further, as shown in FIG. 9, a vortex adjustment piece 22 is installed between the rotary table 3a and the rotary plate 7, similar to the vertical mill shown in FIG. Of course, the plate 21 may be attached.

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 mill can be packed into a single unit, it does not require a complicated mechanism or a large amount of power for the transfer means unlike conventional devices, and furthermore, since the crushing section and the classification device are integrated, it is possible to downsize the vertical mill. Furthermore, since the crushing section and the classifier operate independently, they are hardly influenced by each other, and therefore the crushing section and the classifier can operate very efficiently, economically and stably. In addition, the coarse powder obtained after classification is
Since it can be recovered as a product without being re-pulverized, it has the advantage of increasing the range of applications.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of a conventional vertical mill, Fig. 1 is a schematic explanatory diagram of a vertical mill according to the present invention, Fig. 3 is a sectional view taken along line A-A in Fig. 2, and Fig. 4 5 is a schematic explanatory view of another embodiment of the vertical mill according to the present invention; FIGS.
FIG. 9 is a schematic explanatory diagram of yet another embodiment of the vertical mill according to the present invention. In the figure, 1: vertical mill, 2a: crushing section casing, 2c: classifier casing, 2d: coarse powder cone, 3: crushing section, 6: classifier, 7: subdivision discharge pipe, 50
: Rotating vertical shaft, 9: Rotating plate, 1O: Dispersion plate, 11: Collision plate, 12: Guide vane, 20: Classification chamber, 21: Partition plate,
22: Vortex adjustment piece, 40: Raw material, 41: Pulverized product, 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., includes a crushing section having a crushing roller provided to roll on a rotating table, and a crushing section below the crushing section. A vertical mill integrally equipped with a classification device having a rotary plate attached to a hollow rotary shaft arranged and concentric with the drive shaft of a rotary table in a crushing section. 2. The classifier consists of a spiral classifier casing having a fluid inlet, a rotating vertical shaft provided approximately at the center of the classifier casing, a rotary plate mounted on the rotating vertical shaft, and a rotating plate inside the classifier casing. It consists of multiple guide vanes installed at a distance around the outer circumference of the rotating plate, a coarse powder cone installed at the bottom of the classifier casing, and a fine powder discharge pipe installed at the bottom of the rotating plate. 2. The vertical mill according to claim 1, wherein the pulverized material is classified by a vortex and rotation of a rotary plate. 3. The vertical mill according to claim 2, characterized in that a dispersion plate is mounted on a rotating vertical shaft above the rotating plate. 4. The vertical mill according to claim 2 or 3, wherein a drive shaft for rotating the rotary table extends through the inside of the rotating vertical shaft. 5. The vertical mill according to claim 2, wherein the rotary table and rotary plate are mounted on a rotating vertical shaft. 6. The vertical mill according to claim 4 or 5, characterized in that a plurality of eddy current adjusting pieces are attached to the rotary plate. 7. The vertical mill according to claim 6, characterized in that a partition plate is horizontally attached to the vortex adjustment piece to divide the classification chamber into a plurality of sections. 8. The vertical mill according to any one of claims 4 to 7, characterized in that a secondary fluid intake port is provided in the tangential direction of the classifier casing. 9. The vertical mill according to any one of claims 4 to 5, characterized in that a tertiary fluid intake port is provided in the coarse powder cone. 10. The vertical mill according to any one of claims 4 to 9, characterized in that the coarse powder after classification is transported to a crushing section by a transporter such as a packet elevator to be re-pulverized. .