JPH0619833U - Vertical mill - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] It is possible to separate iron particles from the crushed product in a high concentration and reliably in a rigid mill that grinds granulated slag containing iron particles. Improves driving stability. An endless annular gas blowing port 11 is provided between the outer peripheral portion of the table 3 against which the crushing roller 7 is pressed and the outer side of the outer peripheral portion in the radial direction. An extraction port 19 having a smaller flow velocity than the gas blowing port is provided near the outside.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vertical mill that can be implemented for crushing, for example, granulated slag containing iron particles.

[0002]

[Prior art]

 Granulated slag from a blast furnace generally contains 0.2 to 1% of iron particles. Conventionally, such granulated slag is supplied to a vertical mill for crushing by interposing it between a table that is driven to rotate around a horizontal axis of rotation and a crushing roller that is pressed against the table and is driven to rotate. The pulverized powder is conveyed and classified by the gas blown up from the outer periphery of the table. Granulated slag is mainly composed of CaO and is smaller than the specific gravity of iron particles contained in the granulated slag. Therefore, although the crushed slag powder is carried by the gas stream, the iron particles are slag. As described above, it is hard to become fine powder, and the specific gravity is large as described above, so it is hard to be removed from the upper surface of the table, and iron particles stay on the upper surface of the table and are gradually concentrated. The problem of wear arises. That is, when iron particles are concentrated and remain on the table for a long time, not only the crushing efficiency is lowered due to the formation of the iron particle layer, but also the hard iron particles are crushed and the slag crushing efficiency is lowered. As a result, the wear of the table and the grinding roller will be accelerated.

Another prior art for solving this problem is disclosed in Japanese Utility Model Publication No. 2-137933. In this prior art, an annular nozzle having a plurality of air ejection ports is provided between the outer peripheral portion of the table and the inner wall of the casing, and at least one of these ejection ports is provided with a recovery chute. Connecting. At the air ejection port to which this chute is connected, the ejection velocity is lower than the ejection velocity of the air blown upward from the wind box through the remaining air ejection port, or the ejection velocity is zero, so the particle size is large. The iron particles, which have a higher specific gravity than the coarse powder, are recovered through the recovery chute.

[0004]

[Problems to be solved by the device]

 In such a prior art, the recovery chute is connected to at least one of the plurality of air jets forming the annular nozzle, and therefore, the air is jetted in a ring shape from all the air jets. is not. Therefore, it is difficult to uniformly and smoothly convey the powder from the table for classification, and it becomes difficult to operate the vertical mill stably.

Further, in this prior art, not only the recovery capacity is low because the number of recovery points is limited, but also a large amount of slag powder is mixed in the powder from the recovery chute in addition to iron particles. Therefore, in order to select only iron particles from a mixture with iron particles containing a large amount of slag powder from such a recovery chute, the separation efficiency of the magnetic separator decreases and a large magnetic separator must be used. I need.

Further, in this prior art, as described above, a large amount of slag powder is contained in the iron particles from the recovery chute, and the dried slag powder thus recovered is re-converted to the vertical mill. When thrown in and crushed, the bite between the table and the crushing roller deteriorates, which adversely affects the stable operation of the vertical mill. Further, since the amount of slag powder that circulates through the recovery chute is large in this way, the amount of circulating slag powder also fluctuates greatly in response to changes in operating conditions, making it difficult to maintain stable operation.

An object of the present invention is to provide a vertical mill capable of more efficiently selecting and removing powder having a large specific gravity such as iron particles contained in an object to be ground such as slag. It is to offer.

[0008]

[Means for Solving the Problems]

 According to the present invention, an endless annular gas blow-up port is provided between the outer peripheral portion of the table against which the crushing roller is pressed and a portion radially outward of the outer peripheral portion. The vertical mill is characterized in that at least a portion in the circumferential direction is provided with a take-out port having a flow velocity smaller than that of the gas blowing port, radially outward of the gas blowing port.

[0009]

[Action]

 According to the present invention, an endless annular gas blow-out port is formed on the outer peripheral portion of the table. Therefore, the gas blow-up port is continuous and there is no stop in the circumferential direction. Therefore, the powder such as slag after crushing on the table is smoothly blown up along the entire circumference to be transported and classified. Therefore, it is possible to continue stable operation of the vertical mill.

A powder having a specific gravity larger than that of the slag powder on the table, for example, iron particles, moves the gas blown up from the gas blow-up port across the table in the radial direction outward, and moves to the gas blow-up port. The slag with a smaller specific gravity rises to the rising gas flow in this part as well, and the iron particles with a large specific gravity fall instead of rising due to the rising gas. Therefore, the mixture with the slag powder or the like having a high concentration of iron particles having a large inertial force can be recovered from the outlet. Therefore, most of the recovered mixture is iron particles, so that the recovery efficiency of iron particles in a small-sized magnetic separator can be increased, and iron particles of high purity can be obtained. Further, since the amount of the iron particle mixture containing the slag powder recovered in this way from the outlet is relatively small, the magnetic separator may be small as described above.

Furthermore, when the slag powder after being collected from the outlet and sorted is re-charged to the vertical mill, the circulation amount of the slag powder is extremely smaller than that of the above-mentioned prior art. It is the quantity, which makes it possible to improve the operational stability of the vertical mill.

In order to further ensure the recovery of the iron particles, the take-out port may be formed radially outward of the gas blowing port of the table, and may be formed over the entire circumference of the table. As a result, it is possible to more reliably recover the iron particles, and it is possible to solve the problem that the iron particles remain on the table and are concentrated.

[0013]

【Example】

 FIG. 1 is a partial sectional view of a vertical mill 1 according to an embodiment of the present invention, and FIG. 2 is a sectional view of the entire vertical mill 1. With reference to these drawings, a table 3 having a vertical rotation axis 2 is rotationally driven by a drive source 4, and a table liner 5 of the table 3 is pressed against a grinding roller 7 having a roller tire 6. The crushing roller 7 is driven to rotate according to the rotation of the table 3.

A wind box 9 is provided in the housing 8 of the vertical mill 1, and air is supplied to the wind box 9 from a pushing fan 10 or sucked by a fan 15. The slag powder of the water granulated slag, which is crushed by being caught between the table 3 and the crushing roller 7, is fed from the endless annular gas blowing port 11 formed outside the outer peripheral portion of the table 3. It is conveyed by the air jet shown by the arrow 12, classified by the classifier 13, collected by the bag filter 14, and attracted by the clean air centrifugal fan 15 to be discharged. In the wind box 9, for example, it is −20 to −100 mmAq, and the velocity of the air at the gas blow-up port 11 is, for example, 30 to 50 m / sec. Granulated slag from the blast furnace to be crushed is introduced from the conveyor 16 through the airlock feeder 17 and from the chute 18 near the center of the table 3. The powder dropped from the gas blow-up port 11 and an outlet 19 described later is moved in the wind box 9 by a scraper 21 fixed to the table 3, and is discharged from an exhaust port 22 formed at the bottom of the wind box 9. , And is conveyed by the conveyor 22 via an air lock damper and the like.

The powder from the conveyor 22 is lifted by the elevator 23 and guided to the magnetic separator 24. The magnetic separator 24 has a semi-cylindrical fixed permanent magnet piece 25 and a sleeve 27 made of a non-magnetic material that is rotatably driven in the direction of an arrow 26 on the outer circumference thereof. In this way, the iron particles are magnetically attracted to the outer peripheral surface of the sleeve 27 and discharged to the outside through the outlet 28, and the slag powder from which the iron particles have been removed is returned from the chute 29 to the vertical mill 1 via the feeder 17.

FIG. 3 is a horizontal sectional view around the outer peripheral portion of the table 3 shown in FIG. An overhang portion 31 protruding inward in the radial direction is annularly formed and fixed to the outer peripheral portion of the table 3. Between the table 3 and the housing 8 of the vertical mill 1, there is provided a collision plate 33 which projects above the overhang portion 31 and extends over the entire circumference of the table 3. The collision plate 33 is fixed to the inner surface of the housing 8 by the support member 34. A guide plate 35 forming the take-out port 19 is fixed to the collision plate 33 by the side wall 36. Below the guide plate 35, a plate-shaped swing member 38 is provided by a horizontal hinge pin 37. An operating rod 40 is connected to the swinging member 38 by a pin 39. By setting the operating rod 40 to move back and forth in the direction of an arrow 41, the tilt angle of the swinging member 38 is adjusted, and the takeout operation is performed. The flow rate of the air entering from the inside of the wind box 9 to the mouth 19 is changed, and thereby the flow velocity of the air blown up inside the take-out mouth 19 is adjusted to a small value or zero, which is less than the air blow-up speed of the blow-up mouth 11. Can be done.

Powder such as slag powder containing iron particles crushed between the table liner 5 and the roller body 6 of the crushing roller 7 on the table 3 is moved by the centrifugal force generated by the rotation of the table 3 to cause an arrow. Move in the direction of 42. The powder first collides with the upward flow of air indicated by arrow 12 from the blow-up port 11 and almost all of the slag powder having a small specific gravity and therefore a small inertial force is generated by the upward flow of arrow 12. It is transported upward. On the other hand, the iron particles having a large specific gravity and a large inertial force penetrate the upward flow of air indicated by the arrow 12, collide with the collision plate 33 and stall, and as shown by the arrow 43 from the outlet 19. Drop to. The iron particles are hard to be crushed and have a large particle size, and the slag has a specific gravity of about 2.9 g / cm ³ , whereas the iron particles have a specific gravity of 7.98 g / cm ³ , and therefore the specific gravity of the iron particles is large. Is about 2.7 times the specific gravity of the slag powder, so there is a large difference in inertia.

The rising air flow velocity at the take-out port 19 is lower than the flow velocity of the air at the blow-up port 11, whereby iron particles can be reliably recovered from the take-out port 19. For this purpose, when the operating rod 40 is operated and the width of the lower portion of the gas blowing port 11 in FIG. 1 is set to WG and the width of the lower portion of the take-out port 19 is set to WM,

[0019]

## EQU1 ## When WM <WG is selected, and when the upper width of the gas blowing port 11 is L1 and the upper width of the take-out port 19 is L2 as shown in FIG.

[0020]

## EQU00002 ## It is preferable to select L2 <L1 / 2. The above-mentioned swing member 38 functions as a damper for adjusting the flow rate of the air that enters the take-out port 19 from the wind box 9, and thereby reliably lowers the wind speed at the take-out port 19.

FIG. 4 is a simplified plan view of another embodiment of the present invention, and FIG. 5 is a sectional view taken along the section line VV of FIG. This embodiment is similar to the previous embodiment, and corresponding parts bear the same reference numerals. It should be noted that in this embodiment the outlet 19 is formed radially outward of the impingement plate 33. Other configurations are the same as those in the above-mentioned embodiment.

FIG. 6 is a horizontal sectional view of a part of another embodiment of the present invention, FIG. 7 is a sectional view taken along section line VII-VII of FIG. 6, and FIG. 8 is a sectional view of FIG. FIG. 8 is a cross-sectional view taken along the line VIII-VIII. This embodiment is similar to the previous embodiment, and corresponding parts bear the same reference numerals. It should be noted that in this embodiment, the gas blow-up port 11 for air is provided with vanes 46, which rectify the upward flow of air in the same direction as the rotation direction of the table 3 or in the opposite direction. . The guide plate 35 is fixed between the blades 46 to form the ejection port 19. Other configurations are the same as those in the above-mentioned embodiment. As another embodiment of the present invention, the swing member 38 and the operating rod 0 may be provided in the same manner as described above as another embodiment of the present invention by modifying the configuration of the embodiment of FIGS.

FIG. 10 is a horizontal cross-sectional view of a part of a further embodiment of the present invention, FIG. 11 is a sectional view in the circumferential direction taken along the line X-X of FIG. 10, and FIG. FIG. 11 is a sectional view taken along section line XI-XI in FIG. 10. This embodiment is similar to the above-described embodiment, and corresponding parts are designated by the same reference numerals. A collision plate 33a is formed radially outward of the table 3 with respect to the collision plate 33 on which the rotary blades 46 are formed, through a notch 47, and an ejection port 19 is formed therein. Such embodiments are also within the spirit of the invention. The rocking member 38 and the operating rod 40 may be provided as shown in FIG. 13 by modifying the configuration of the embodiment shown in FIGS.

[0024]

[Effect of device]

 As described above, according to the present invention, an endless annular gas blow-out port is provided on the outer peripheral portion of the table, whereby gas such as air is blown up from the entire outer peripheral portion of the table to be pulverized. It is possible to transport and classify slag powder, etc., which makes the vertical mill extremely stable in operation.

Further, according to the present invention, an outlet having a small flow velocity is provided radially outward of the gas blowing port, and iron particles having a large specific gravity and thus a large inertial force cross the blowing port. It is collected from the outlet. Therefore, most of the powder collected from the take-out port is iron particles, which increases the efficiency of the magnetic separator, and it is possible to collect high-purity iron particles. Contains a small amount of slag, etc., so the magnetic separator can be made smaller and better. Also, since the amount of slag powder obtained from this outlet is small as described above, when the recovered slag powder is fed back into the vertical mill and circulated, stable operation of the vertical mill is achieved. There is no disturbance in sex.

Further, according to the present invention, the iron particle concentration on the table can be significantly reduced, so that the unit consumption of wear [g / ton-slag] of the table liner and the roller tire is significantly reduced. The life of the table liner and the roller tire can be remarkably extended, continuous operation for a long time is possible, and the grinding efficiency can be improved.

[Brief description of drawings]

1 is a partial vertical cross-sectional view of an embodiment of the present invention.

FIG. 2 is an overall system diagram of an embodiment of the present invention.

FIG. 3 is a table 3 of the embodiment shown in FIGS. 1 and 2.
FIG. 4 is a horizontal cross-sectional view near the outer peripheral portion of FIG.

FIG. 4 is a horizontal cross-sectional view of an outer peripheral portion of a table 3 according to another embodiment of the present invention.

5 is a cross-sectional view of the embodiment shown in FIG. 4 taken along section line VV.

FIG. 6 is a horizontal cross-sectional view of the outer periphery of a table 3 according to another embodiment of the present invention.

FIG. 7 is a development cross-sectional view in the circumferential direction taken along the section line VII-VII in FIG.

FIG. 8 is a sectional view taken along section line VIII-VIII in FIG.

FIG. 9 is a sectional view showing a part of another embodiment obtained by modifying the embodiment shown in FIGS. 6 to 8;

FIG. 10 is a horizontal cross-sectional view of a table 3 according to still another embodiment of the present invention in the vicinity of an outer peripheral portion thereof.

FIG. 11 is a development cross-sectional view in the circumferential direction as seen from the section line XX in FIG.

FIG. 12 is a sectional view taken along the section line XI-XI in FIG. 9.

FIG. 13 is a cross-sectional view showing a part of another embodiment obtained by modifying the embodiment shown in FIGS.

[Explanation of symbols]

 1 Vertical mill 3 Table 7 Grinding roller 8 Casing 11 Blow-up port 19 Ejection port 24 Magnetic separator 33 Collision plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Hashimoto 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe City Kawasaki Seki Heavy Industries Ltd. Kobe factory (72) Inventor Susumu Uchiyama 3-chome, Higashikawasaki-cho, Chuo-ku, Kobe No. 1 Inside Kawasaki Heavy Industries, Ltd. Kobe factory (72) Inventor Junji Suetsugu 3rd light, Kashima-cho, Kashima-cho, Kashima-gun, Ibaraki Prefecture Sumitomo Metal Industries, Ltd. Kashima Works (72) Inventor Susumu Tomita Kashima-machi, Kashima-gun, Ibaraki Sumikin Kashima Mineralization Co., Ltd. (72) Inventor Tomoki Miyata Kashima-cho, Kashima-gun, Ibaraki Prefectural Sumikin Kashima Mineralization Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. An endless annular gas blow-up port is provided between an outer peripheral portion of a table against which a crushing roller is pressed and a radial outer side of the outer peripheral portion. A vertical mill characterized in that at least a part in the circumferential direction is provided with a take-out port having a flow velocity smaller than that of the gas blowing port, radially outward of the gas blowing port.