JPH0377748A - Brushing device for strip continuous casting machine - Google Patents

Abstract

PURPOSE:To prevent crack, etc., caused by contamination of cooling drums by arranging brush in slide contact with a part of the surface of rotating cooling drum and sucking and discharging the caught contamination with negative pressure. CONSTITUTION:A disk-like suction cover 6 covering a part of the surface of rotating brush 5 over the axial direction is arranged as fixing to a tool frame, etc. A suction hose 7 is connected with a negative pressure source, such as vacuum pump, suction blower, and contaminate powder is separated through suitable separator on the way of this. By this method, a cast strip 4 without any defect can always be produced stably.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to forming a pool on a part of the circumferential surface of a cooling drum constituting a mold, such as in a twin-drum system.
The present invention relates to a brush device that comes into sliding contact with the surface of the cooling drum in a continuous casting machine that produces thin slabs by cooling and solidifying molten metal injected therein.

[Conventional technology]

BACKGROUND ART Recently, a method of directly producing thin slabs having a wall thickness of about 1 to 10 seconds from molten metal such as molten steel using a continuous casting machine has been attracting attention. According to this continuous casting method, there is no need to manufacture thin plates from a thick slab through a multi-step hot rolling process as in the past, and the cold rolling required to form the slab to its final thickness is also light. Therefore, a large economic effect can be obtained by simplifying the process and equipment, and it is often preferable from the viewpoint of metallographic structure.

This type of continuous casting method includes a twin drum method in which a pool 3 is formed between a pair of cooling drums 1 and 2 that rotate in opposite directions, as schematically shown in FIG. 2, and a cooling drum method (not shown). There is a drum-belt method in which a water reservoir is formed between the cooling drum and the belt, and a single drum method in which a water reservoir is formed in a part of one cooling drum.

In both of these methods, the molten metal in the sump 3 is cooled at the part where it contacts the surface of the cooling drum 1.2 and begins to solidify from the surface, forming a solidified shell while moving toward the center of the thickness. Coagulation progresses gradually. Therefore,
If contamination such as oxides of molten metal is partially adhered to the surface of the cooling drum 1.2, dents will remain on the surface of the thin slab 4 depending on the thickness of the contaminant (contamination). Not only that, but also the heat conductivity is different between parts with deposits and parts without them, so cooling progresses unevenly on the surface of the slab 4, which causes the slab to deteriorate. The thickness of 4 may become uneven, and wrinkles and cracks may occur.

Therefore, it has been considered to scrape off the deposits (dirt) on the surface of the cooling drum 2 with a rotating brush as exemplified as 5 in FIG.
Inventions such as those described in Japanese Patent Application Laid-open No. 176650/1983 have been proposed.

[Problem to be solved by the invention]

The rotary brush 5 according to the prior art is provided for the purpose of scraping off deposits (dirt) on the surface of the cooling drum 2, but it is not always possible to reliably prevent cracks in the slab 4. do not have. Rather, if the scraping action by the rotating brush 5 is not completed completely due to dirt accumulation, etc., and the deposits remain in the form of lines on the surfaces of the cooling drums 1 and 2, vertical cracks may occur on the surface of the slab 4. occurs. Furthermore, when the white body of the rotating brush 5 becomes heavily contaminated, the centrifugal force generated by the rotation of the rotating brush 5 may cause the rotating brush 5 to blow off the dirt, or the rotating brush 5 may become eccentric or deviate from a perfect circle, causing the cooling drum 1. Periodically, thick areas of deposits remain on the surface of the slab 4 like horizontal stripes, which can cause defects such as horizontal cracks on the slab 4, and these A new problem is emerging.

[Means to solve the problem]

The brush device for a thin plate continuous casting machine of the present invention is provided with a brush that comes into sliding contact with a part of the surface other than the pool of a rotary cooling drum constituting a mold for continuous casting, and dirt that is captured by the brush. The brush is characterized in that the brush is sucked and discharged by negative pressure acting on a suction space provided in cooperation with the brush.

[For production]

Since the present invention has the above-mentioned configuration, deposits (dirt) such as molten metal oxides that irregularly adhere to the surface of the cooling drum in the water pool are removed by the brush that is in sliding contact with the cooling drum. The powdered dirt is captured as a powder, and due to the negative pressure acting on the suction space provided in cooperation with the brush, the powdered dirt is sucked to the outside and discharged, and is irregularly deposited on the cooling drum. No stains remain in the form of streaks, stripes, etc. Therefore, damage such as cracking caused by contamination of the cooling drum does not occur to the slab.

〔Example〕

FIG. 1 shows an embodiment of the present invention. Points similar to those of the above-mentioned prior art shown in FIG. 2 are given the same reference numerals and explanations will be omitted. In the present invention, instead of the rotating brush 5 shown in the embodiment, a non-rotating brush (including a brush that does not rotate but vibrates) may be used. The non-rotating brushes are always in sliding contact with a part of the surface of the cooling drum 1 (and 2 as well), and there is no risk of the dirt being thrown away by centrifugal force, but dirt accumulates between the bristles of the brush. Therefore, it is very effective to constantly remove dirt by providing a means such as the present invention.

As a feature of the present invention, in the embodiment shown in FIG.
A dish-shaped suction cover 6 that covers part of the surface of the machine in the axial direction is fixed to a machine frame (not shown) or the like. Since it is effective to provide the suction cover 6 at a position immediately after the rotating brush 5 leaves the surface of the cooling drum 1, the installation position is determined depending on the rotation direction of the rotating brush 5. In the case of a non-rotating brush, it is preferable that the plywood on which the brush fibers m (thin metal or non-metallic wires, etc.) are implanted is made hollow to serve as a suction space, and a large number of holes, grooves, etc. are provided in the implanted portion. Moreover, even if the rotating brush 5 as shown in FIG. 1 is made hollow and a large number of suction holes are provided on the surface on which the bristles are implanted, the suction space formed by the suction cover 6 shown in FIG. It is also possible to form a space in the rotating brush 5 that has the same effect.

In Fig. 1, 7 is a suction hose, which is connected to a negative pressure source such as a vacuum pump or a suction blower, and a suitable separation device is interposed in the middle to separate dirt powder. . When suctioning from inside the rotating brush 5, a thick hollow shaft connected to the suction hose 7 may be provided at the center of the rotating brush 5, and the dirt powder may be guided outside through it.

FIG. 3 is an example showing a comparison of the amount of dirt remaining on the rotating brush 5 of the present invention and the conventional example. In the conventional example shown in FIG. 2, since dirt accumulates on the rotating brush 5, the operation is stopped every time t1 and the rotating brush 5 is cleaned.
It needs to be replaced, and the amount of dirt shows a sawtooth increase/decrease (double-dashed line) with a cycle of time tl. Cleaning period 1. If the time is longer, the dirt powder captured on the rotating brush 5 becomes saturated, and the amount of dirt powder that is thrown off by the rotation increases, re-contaminating the surface of the cooling drum 1.2. Therefore, the upper limit of the amount of dirt in FIG. 3 is determined by the permissible limit. However, it is difficult to prevent defects in the slab 4 from increasing as the upper limit is approached.

On this point, in the case of the present invention, the rotating brush 5 is
Or, since the dirt powder is sucked and discharged from the non-rotating brush by the suction space, the amount of dirt on the brush hardly increases, so it becomes like the horizontal straight line in Figure 3, and is always stable. Thus, it becomes possible to manufacture a slab 4 without defects.

Further, there is no need for cost or time loss for cleaning or replacing the rotating brush 5.

In addition, by analyzing and measuring the discharged dirt powder, the Ni I contained therein was quantified, and the cooling drum 1
．． 2. The progress of wear can be grasped during operation. Based on this information, you can adjust the brush contact and determine when it is time to replace the cooling drum.

〔Effect of the invention〕

Since the present invention has the above-described structure and operation, it is possible to remove deposits (dirt) scraped off by the brushes that come into sliding contact with the surface of the cooling drum during operation, thereby preventing dirt from accumulating on the brushes. and it is less likely to contaminate the cooling drum again. Therefore, causes of defects such as cracks in the slab are eliminated, and thin slabs of good quality can be stably and continuously cast.

Furthermore, since there is no need to clean or replace the brushes over a long period of time, it is very advantageous from the viewpoint of cost and work efficiency.

Furthermore, N contained in the dirt powder that was sucked and discharged
By measuring the amount of Ni on the cooling drum surface,
It is also possible to monitor the amount of wear caused by brushing the plating.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a perspective view showing a conventional example, and FIG. 3 is a diagram comparing the amount of dirt between the present invention and the conventional example. 1.2... Cooling drum, 3... Hot water reservoir, 4...
Thin slab, 5...Rotating brush, 6...Suction cover 7...Suction hose.

Claims (1)

[Claims] A brush is provided that comes into sliding contact with a part of the surface other than the sump of the rotary cooling drum constituting the mold for continuous casting, and a suction device is provided that cooperates with the brush to remove dirt captured by the brush. A brush device for a thin plate continuous casting machine, characterized in that the brush device is designed to suction and discharge by negative pressure acting on the space.