JP2000227282A - Method and apparatus for discharging slag by multi-arm type dragger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease molten allowed to get by to almost zero by longitudinally superposing a plurality of scraping plates with arms and arranging the plates, laterally moving the plates and extending or contracting the overall length of the row. SOLUTION: An interval of arms 3 is regulated so that scraping plates 2 approach at the very limit of innermost or inside surface of a container 1. Thereafter, a moving means mounting all the arms 3 is moved rearward, and all the plates 2 are simultaneously moved at the same amount in the direction of the arms. That is, first an interval of the outermost arms is broadened while moving the plates 2 in the direction of the arms, then adjacent inside plates 2 are also moved to outside, and further its inside plates 2 are similarly moved, thereby regulating so that the interval between the plates 2 and the inside surface of the container to minimum. Thus, all the plates 2 are moved to eliminate the gaps between the inside surface of the container and the plates 2 and the gap between the plates 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for discharging slag, and more particularly to a method for removing slag on a molten metal by a dragger and an apparatus for enabling the method.

[0002]

2. Description of the Related Art In the smelting process in the recent steelmaking industry, in order to reduce costs and improve the quality of steel materials, hot metal pretreatment of de-Si, de-P, and de-S is performed outside the furnace from the former batch refining of converters. Then, the converter has shifted to a process for obtaining ultra-clean steel such as ultra-low phosphorus steel and ultra-low sulfur steel, which aims for decarburization and high-efficiency alloying. In such a process, it is important to remove the slag generated in each refining step completely or quickly with a necessary amount remaining.

[0003] In the removal of slag, techniques such as separation of slag and metal by a weir (for example, Japanese Utility Model Application Laid-Open No. 55-49892) and vacuum suction type slag (Japanese Patent Application Laid-Open No. 60-91186) are known. As is known, in actual operation, mechanical waste by draggers is used in most cases. However, this dragger-type waste disposal method has problems in slag removal rate, productivity, and workability, and many improvement measures have been proposed so far.

[0004] In the actual process, the scraping plate is smaller than the container and only one sheet is used, and the time that can be spent for the waste is limited, and as a result, the next process is performed while leaving a large amount of the slag. The fact is that it moves. In order to increase the efficiency, it is conceivable to enlarge the scraping plate,
It is normal to tilt the container to scrape it out of the container at the time of waste disposal, so it can only take a cantilever structure,
Large scraped boards cannot be used. Therefore, an attempt was made to increase the efficiency by using a plurality of scraping plates (Japanese Patent Application Laid-Open No. 2-130389), but the slag could not be prevented from retreating, and the operation pattern was fixed to several types. It was not a decisive improvement, such as scratching unintended places. Thus, most remedies are
At present, decisive improvements have not been made in a short period of time, even when used in actual operations.

[0005]

As described above, in the slag removal operation in the smelting process, quick and highly efficient slag removal is required to obtain a desired steel composition while preventing heat loss. At present, dragger waste is mainly used, but there are problems with its removal rate, productivity, and workability. In view of the above, an object of the present invention is to provide a method for efficiently and quickly removing a slag in a dragger slag method that is currently mainstream, and an apparatus that enables the method.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the gist of the present invention is as follows: (1) A method for discharging slag on a molten metal held in a molten metal container, , A scraping plate with multiple arms,
Arrange left and right with overlapping parts at the front and back, move the scraping plate left and right as far as the overlapping part remains, expand and contract the entire length of the row of scraping plates according to the shape of the container, and scrape the slag in the container A multi-arm dragger waste disposal method characterized by the following. (2) In the overlapping portion of the adjacent scraping plates, the distance dmm and the length lmm are in a range of 5 mm ≦ d ≦ 50 mm and satisfying 1 / d ≧ 5 in a state where the plate is expanded to the maximum. The multi-arm dragger waste disposal method according to 1). (3) It has a plurality of scraping plates with arms arranged in parallel, and the adjacent scraping plates are arranged so as to overlap each other before and after, and all the arms are attached to one moving means. In the same direction in the same direction, and does not interfere with the operation of the horizontal and vertical scraping plates perpendicular to the arm, and a driving means is provided on the arm separately from the moving means. A multi-arm type dragger discharging device characterized in that it moves vertically and moves in a horizontal direction perpendicular to the arm and does not interfere with the movement of the scraping plate in the arm direction. (4) It has a plurality of scraping plates with arms arranged in parallel, and the adjacent scraping plates are arranged so as to overlap each other before and after, and all the arms are attached to one moving means. A multi-arm dragger discharging device characterized in that it can be simultaneously moved in the same direction in the same direction, and the scraping plate can be moved in a horizontal direction perpendicular to the arm ascending and descending. It is.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides an arrangement in which a plurality of scraping plates are arranged so as to overlap each other, and the total length thereof is made variable according to the shape of the container. It enables high efficiency and quick waste disposal.

[0008] After tapping the blast furnace, or desiliconization, dephosphorization, desulfurization,
The torpedo car, ladle, and converter containing the molten iron or molten steel in which the molten metal after decarburization or degassing is placed are tilted to the container 1 just before the molten iron or molten steel flows. Adjusting the distance between the arms 3 to the innermost part of the container as viewed from the working position so that the scraping plate 2 comes very close to the inner surface of the container (position a in FIG. 1). Thereafter, by moving the moving means 4 (FIG. 2) to which all the arms 3 are attached to the rear, all the scraping plates 2 are simultaneously moved in the arm direction by the same amount. In FIG.
Although the moving means 4 is provided at the end of the arm 3, the moving means may be provided on a side near the scraping plate 2 other than the end of the arm.

In order to simplify the structure, the moving means 4 preferably has no driving force for raising and lowering the arm and moving in a horizontal direction perpendicular to the arm. As an example, the apparatus example of FIG. 3 can be considered. In this example, the wheels 7 are rotated by the driving device 6 and moved on the rail 8 so that all the arms 3 attached to the device can be simultaneously moved by the same amount. In this case, a structure that does not interfere with the vertical movement of the arm and the vertical movement of the arm is required. Therefore, in the example of FIG.
Is connected to the mounting jig 9 so that the arm 3 can be tilted with the mounting position as a fulcrum, and the lower part of the mounting jig 9 is fitted into the through groove 10.
It has a degree of freedom in horizontal movement perpendicular to the arm 3 and is firmly connected to this moving means.

In the case where the moving means 4 is not provided with a driving force for the horizontal movement at right angles to the arm,
By providing the driving means 5 (FIG. 2) separately from the moving means 4, the scraping plate 2 is moved according to the shape of the container. FIG. 2 shows an example in which the driving means 5 is provided between the moving means 4 and the container 1, but the driving means 5 may be provided at a position farther from the container than the moving means 4. When the scraping plate is moved in parallel with the arm direction, a gap is created between the scraping plate and the inner surface of the container. Therefore, the distance between the outermost arm is widened while moving in the arm direction, and the distance between the scraping plate and the inner surface of the container is adjusted to be minimum. At that time, if a gap is formed between the outermost scraping plate and the adjacent inner scraping plate, the slag will be lost, so the adjacent inner scraping plate is also moved outward. Further, the scraping plate on the inside is moved in the same manner.
By moving all the scrapers in this way,
The gap between the inner surface of the container and the scraping plate and between the scraping plates can be eliminated, and the slag retraction can be minimized (position b in FIG. 1). If the number of scraping plates is odd, fix the central arm so that it cannot move in the horizontal direction perpendicular to the arm.

Although raising and lowering of the arm by the moving means 4 is conceivable, it is preferable to raise and lower the arm by driving means 5 which is responsible for horizontal movement perpendicular to the arm, for the sake of simplicity of the apparatus. The scraping plate is moved to the foreground, and the distance is adjusted while raising the scraping plate so as not to damage the container when removing the collected slag out of the container. This is defined as one scraping. By moving the scraping plate to the innermost part of the container while raising the scraping plate and arranging the scraping plates as before and repeating the scraping, the slag can be almost completely removed by scraping several times.

FIG. 4 shows an example of the driving means 5 when the apparatus shown in FIG. 3 is used as the moving means 4. In this example, the horizontal movement perpendicular to the arm 3 is performed by a driving device 11 by a jig 14 attached to a chain 13 via a gear 12. The jig 14 has a degree of freedom for movement in the arm direction. The raising and lowering of the arm 3 is performed while adjusting the displacement of the hydraulic device 15. Changing the displacement amount of the two hydraulic devices 15 corresponds to the inclination of the arm 3 that occurs when the height of the moving unit 4 does not change.

As another example of the driving means 5 when the apparatus of FIG. 3 is used as the moving means 4, an example of the apparatus of FIG. 5 using a rail can be considered. In this case, the arm 3 does not need to have a driving force related only to the movement in the horizontal direction perpendicular to the arm 3, and the apparatus is further simplified. When the arm is moved so that the entire length of the scraping plate matches the shape of the container, a locus drawn at a certain point on the arm naturally becomes a certain locus if the shape and position of the container are determined within a certain range. Jig 1 which reproduces this locus as rail 16 and is fixed to arm 3
When the arm 7 moves along the rail 16, the moving means 4 only provides a driving force for movement in the arm direction.
Horizontal movement perpendicular to the arm is enabled. In addition, by incorporating the hydraulic device 18 into the jig 16, each arm can be moved up and down.

FIG. 6 shows an example of an apparatus in which there is no room for installing the driving means 5 in addition to the moving means 4 due to restrictions on the installation place of the apparatus, and the moving means 4 performs horizontal movement perpendicular to the arm. . FIG. 6 shows an example in which the jig 9 of the moving means of the apparatus example of FIG.
Is attached. The scraper is moved up and down by the hydraulic device 19, and the motor 20 and the wheels 21 move horizontally in a direction perpendicular to the arm.

It is preferable that the scraping plates can be moved up and down independently so that more efficient scraping can be performed. In the example of the apparatus shown in FIG. 4, it is possible to cope with this by attaching a hydraulic device between the jig 14 and the chain 13.

Since movement in the arm direction is performed by one carriage, there are advantages that only one power source for scraping is required, that there is no need to adjust the amount of movement of each scraping plate, and that maintenance is simple. Further, since the lifting and lowering of the arm is not performed by the movable cart, the cantilever structure can be avoided, and the load on the arm can be reduced. Further, since the movement in the horizontal direction perpendicular to the arm is different from the movement in the arm direction as a power source / device, each device is simplified.

The overlap length 1 and the distance d (FIG. 7) between adjacent scraping plates are important for preventing the slag from retreating. If the spacing is narrow, the movement of the scraping plate in the vertical direction of the arm is hindered when the metal or slag adheres to the scraping plate.
If the interval is widened simply to prevent this, it is easy to miss and the efficiency is reduced. Therefore, it is necessary to provide an overlap length corresponding to the interval. Considering the slag as Newtonian fluid, the slag passing through the portion sandwiched by the scraping plate receives frictional force from the wall of the scraping plate, so the displacement per hour in the direction parallel to the wall is proportional to the distance dmm, It is inversely proportional to lmm. Tests were conducted using desiliconization, dephosphorization, desulfurization, decarburization, and degassing slag in the range of 1300 ° C. to 1550 ° C. As a result, l / d ≧ 5 in a state where the maximum spread, that is, a state where the overlap was minimized Is satisfied,
There was little slag behind and efficient removal was possible. l / d
It is not necessary to particularly define the upper limit, but if l is long, the scraped-out plates often adhere to each other due to the adhering metal or slag, so it is preferably 200 or less.

The efficiency was highest when the distance d was in the range of 5 mm ≦ d ≦ 50 mm. If the interval is less than 5 mm, the slag is hardly lost, but if the metal or slag adheres, the scraping plate cannot be moved. If the interval between the scraping plates and the overlapping length can be adjusted during the operation in accordance with the adhesion of the slag and the slag, more efficient waste can be discharged.

As for the size of one scraping plate, one scraping plate must be longer than the length obtained by dividing the maximum diameter of the container by the number of scraping plates in order to trace the shape of the container. However, if the scraping plate is too long, the gap between the scraping plate and the container becomes large when the innermost portion of the container or the slag is taken out of the container, and the efficiency is reduced. Moreover, one scraping plate becomes heavy, and a heavy load is imposed on the arm. As the size of the scraping plate is reduced and the number of the plates is increased, the shape of the container can be traced more accurately. However, the number of the scraping plates is equal to the number of the arms, and the number of the scraping plates cannot be easily increased from the viewpoint of equipment and maintenance. Even if the trace can be traced accurately, if the amount of slag is large, the collected slag passes under the scraper by its own weight and is lost. From the result of FIG. 8 in which the number and the efficiency of the scraping plates were examined, it is understood that the ratio between the number and the efficiency becomes highest when the length is such that the maximum diameter of the container can be covered by 5 to 7 sheets.

It is expected that the number of scraping plates increases the maintenance load. The equipment consumption due to the removal of the slag includes erosion of the scraping plate and fatigue of the arm. Among them, except for the adhesion of the slag and the metal to the scraping plate, the number increases in proportion to the number of times of scraping. In the removal by the method of the present invention, the scraping is completed in a much smaller number of times than the conventional dragger method, so that the total number of times of scraping considering all the scraping plates hardly changes, and therefore, the maintenance load does not increase. .
Further, the adhesion of the slag and the metal to the scraping plate is related to a certain number of times, but once it comes into contact with the molten steel slag, the adhesion is unavoidable. In the present invention, since it is important that a plurality of scraping plates operate in cooperation, if the operation is obstructed by slag and slag adhered between the scraping plates, this must be prevented. . As the means, it is preferable to constantly blow gas on the surface of the scraping plate, or to apply a release agent to the scraping plate.

[0021]

EXAMPLES The hot metal after the dephosphorization treatment and the slag floating on the hot metal in a ladle were subjected to waste disposal according to the method of the present invention.
The hot metal weight was 300 t, the slag was 9 t, the temperature was 1350 ° C., and the container used was a ladle having a maximum inner diameter of 4 m. In this example,
The apparatus shown in FIG. 3 was used for the moving means, and the apparatus shown in FIG. 4 was used for the driving means. It has seven scraping plates made of ordinary steel with a length of 700 mm × height 500 mm × width 200 mm, the interval d between adjacent scraping plates is 10 mm, and the overlapping length 1 is 150 mm each at the time of maximum spreading. And 1 / d = 15. A ladle was set in front of the multi-arm dragger discharging device, and discharging was started.

In the first scraping, 4.5 tons of slag was scraped out, and the slag specific unit was reduced from about 30 kg / t to 15 kg / t. Similarly, in the second time, 2.1 t was scraped out at 8 kg / t,
The third time scrapes 1.5t and 3kg / t, the fourth time 0.6t
Was scraped out to 1 kg / t, and slag was almost completely removed by four scrapings. There is almost no involvement of bullion,
The hot metal weight of the pot remained at 300 t.

For comparison, slag was also removed by a conventional dragger-type waste method using only one scraping plate.
All the tests were performed under the same conditions as above except that the scraping plate was one. As a result, 0.9t of slag was scraped out the first time, and the slag basic unit became 27kg / t. However, the efficiency decreased remarkably with each repetition, and the slag was scraped off even after 5 times of scraping. The total amount was 4.5t, it could only be removed up to about 20kg / t in slag basic unit, and in 20 removals, it was removed up to 7.5t in total amount and 5kg / t in slag basic unit,
After that, the slag was so far removed that further removal was difficult, so the waste was terminated. FIG. 9 shows the result of comparison between the above-described present invention example and the conventional method.

[0024]

According to the present invention described above, by preventing slag from retreating, it is possible to prevent a remarkable decrease in efficiency and to greatly reduce the time required for removal.

[Brief description of the drawings]

FIG. 1 is a view for explaining a method of moving a scraping plate for applying the present invention.

FIG. 2 is a schematic view showing an example of a waste disposal apparatus according to the present invention.

3A is a plan view of an example of the moving means 4 in the waste discharging apparatus, FIG. 3B is a cross-sectional view taken along the line AA ′, and FIG.
The elevation view of plane C '.

FIG. 4A is a plan view of an example of a device of a driving unit 5, and FIG.
Is an elevation of the BB 'plane, (c) is an elevation of the CC' plane,
(D) is an elevation view of the DD ′ plane.

5A is a plan view of an example of the apparatus of the present invention, and FIG. 5B is an elevation view of the example of the apparatus of the present invention.

6A is a plan view of an example of the apparatus of the present invention, and FIG.
Sectional drawing of the -A 'plane.

FIG. 7 is an explanatory diagram showing the relationship between the interval between scraping plates and the length of overlap.

FIG. 8 is a diagram showing the relationship between the number of scraping plates and the debris removal efficiency.

FIG. 9 is a diagram comparing the relationship between the scraping plate and the slag basic unit between the method of the present invention and the conventional method.

[Explanation of symbols]

DESCRIPTION OF REFERENCE NUMERALS 1 container 2 scraping plate 3 arm 4 arm direction moving means 5 scraping plate driving means 6 driving device 7 wheel 8 rail 9 mounting jig 10 through groove 11 driving device 12 gear 13 chain 14 jig 15 hydraulic device 16 rail 17 jig 18 Hydraulic device 19 Hydraulic device 20 Motor 21 Wheel

Claims (4)

[Claims] 1. A method for discharging slag on a molten metal held in a molten metal container, wherein a plurality of scraping plates with arms are arranged right and left with overlapping portions at the front and back, and the overlapping portion is provided. Move the scraping plate left and right in the area where
A multi-arm dragger drainage method characterized by expanding and contracting the entire length of a row of scraping plates in accordance with the shape of the container to scrape out the slag in the container. 2. In the overlapping portion of adjacent scraping plates, the distance dmm and the length lmm are in a range satisfying 1 / d ≧ 5 in a state of 5 mm ≦ d ≦ 50 mm, and maximally expanded. The multi-arm dragger waste disposal method according to claim 1. 3. A scraping plate with a plurality of arms arranged side by side, wherein the adjacent scraping plates are arranged so as to overlap each other before and after, and all the arms are attached to one moving means.
The moving means is capable of simultaneously moving the scraping plate in the arm direction by the same amount, and does not interfere with the operation of the horizontal and vertical scraping plates perpendicular to the arm. A multi-arm dragger discharging apparatus characterized in that the driving means moves up and down the arm and moves in the horizontal direction perpendicular to the arm, and does not interfere with the movement of the scraping plate in the arm direction. 4. A scraping plate with a plurality of arms arranged in parallel, wherein the adjacent scraping plates are arranged so as to overlap each other before and after, and all the arms are attached to one moving means.
The moving means is capable of simultaneously moving the scraping plate in the arm direction by the same amount, and moving the scraping plate in a horizontal direction perpendicular to the arm when the arm is moved up and down. apparatus.