JPH09122838A - Twin roll type continuous casting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deposition of scum and to effectively remove the scum floating on the surface by arranging one pair of scum weir which is in parallel to cooling rolls in a molten metal pool part and has its tip part dipped in the molten metal and a means for sucking and removing the scum stayed in the scum weirs. SOLUTION: In a twin roll type continuous casting device, the surface flow of the poured molten metal 4 is caused from the center part of the molten metal pool part space to both sides in the cooling roll axial direction. The scum 5 floating up on the surface from the inner part of the molten metal is moved to the shaft end part of the cooling roll while being carried by this flow. When the scum moves and approaches the scum sucking hole 24, since gas flow is formed toward the sucking hole 24 with a vacuum pump, the scum 5 is moved to the inner part of the suction hole. When the scum 5 deposits on the sucking hole throat part, since the gas passage is clogged, the negative pressure is rapidly developed and spouted to the scum pool part 14, in which the cross sectional area of the gas passage becomes rapidly large, through an introducing pipe part 10 and the scum is removed before depositing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a twin-drum type casting apparatus using a pair of cooling drums and side dams slidably contacting both ends thereof.

[0002]

2. Description of the Related Art In the prior art, in Japanese Unexamined Patent Publication No. 5-228585, a molten metal pool is formed by a moving cooling wall member as shown in FIG. 4, and molten metal is supplied to the molten metal pool to form a strip shape. In an apparatus for continuously casting a slab, a guide nozzle 51 and a wire supply device 53 in which a scum attachment wire 60 is passed through a guide nozzle 51 and protruded from a tip end portion and the protruding wire 60 is dipped in a molten metal 61 in a basin
And the moving means 8 of the guide nozzle 51 and the wire feeder 53
0 and scum adhering portion removing means 71.

The scum is removed by the scum attachment wire 60.
Is made to project from the tip end portion of the guide nozzle 51 by the wire feeder 53, and this projecting portion is immersed in the molten metal 61 in the molten metal pool portion. Then, the guide nozzle 51 and the wire supply device 53 are reciprocally moved together with the carriage 63 by the moving means 81 to reciprocate the protruding portion over the entire length of the molten metal pool portion and float on the molten metal surface of the front molten metal 61. The scum 5 is attached to the protrusion and removed. When the adhering scum becomes large, the tip end portion of the guide nozzle and the projecting portion are brought out of the molten metal pool portion, and are cut and removed by the scum adhering portion removing means. In such a conventional method, there are disadvantages that the number of movable parts is large and the structure is complicated and large.

[0004]

As described above, when the drum casting is continued for a long time in the continuous casting apparatus, the slag formed in the molten metal floats and the scum floating on the surface of the molten metal is accumulated, and the cooling drum is sequentially cooled. It is rolled up on the surface to form a slab with poor surface quality. It is an object of the present invention to provide a twin-drum type continuous casting apparatus for preventing scum accumulation and efficiently removing scum floating on the surface.

[0005]

The above object of the present invention can be achieved by the following constitution. (1) A pair of cooling drums rotating in opposite directions,
Twin drum continuous consisting of a pair of side weirs in sliding contact with both ends of the drum, and a seal cover provided with a seal gas supply means for shutting off the hot water pool portion defined by the cooling drum and the side weirs from the atmosphere. In the casting apparatus, a pair of scum weirs, which are parallel to the cooling drum and have their tips immersed in the molten metal, and means for sucking and removing scum accumulated between the scum weirs are provided in the casting pool. Twin-drum type continuous casting equipment characterized by

(2) The scum removing means has one end immersed in the molten metal and the other end connected to a scum reservoir, and an exhaust scum conduit provided with a heating means and an external suction means connected to the exhaust scum conduit. Twin-drum type continuous casting device, which is composed of a scum reservoir connected to the.

That is, according to the present invention, a cooling gas rotating in opposite directions and side dams slidingly contacting both ends of the cooling drum define a hot water pool and seal gas for shutting the hot water pool from the atmosphere. A twin-drum type continuous casting apparatus having a seal cover having a supply means, in which the width of the pouring nozzle is narrower than the width of the cooling drum, and the pouring nozzle is provided between the pouring nozzle and the cooling drum in the pool. The suction port of the opened exhaust scum pipe is arranged on the surface of the molten water between the provided scum weirs, the opening of the suction port is partially immersed, and the vacuum pump is activated to discharge the water to the surface of the molten metal. I tried to eliminate the existing scum. The suction ports were installed on both sides of the cooling drum in the axial direction. In addition, a scum reservoir with an enlarged cross-sectional area of the conduit was provided in the middle of the conduit to the vacuum pump. The exhaust scum pipe for eliminating the scum is made of heat-resistant ceramics, and the outer surface of the exhaust scum pipe is covered with metal to reinforce and heated by an electric heater.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Since the twin-drum casting apparatus according to the present invention has the above-mentioned structure, the surface flow of the poured molten metal is from the central portion of the pool space to both sides in the axial direction of the cooling drum. Occurs. The scum floating from the inside of the molten metal to the surface rides on this flow and moves toward the cooling drum shaft end. When moving and approaching the scum inlet, the scum moves inside the inlet because the vacuum pump forms a gas flow toward the inlet. When the scum accumulates in the throat of the suction port, the gas passage is blocked, so that a negative pressure is rapidly generated and discharged through the conduit portion to the scum reservoir where the cross-sectional area of the gas passage is rapidly increased.

In this case, the exhaust scum conduit is made of heat-resistant ceramics, but is reinforced with a metal net so as not to cause chipping. Further, since it is heated by the electric heater to a temperature at which scum does not solidify (for example, 1300 ° C to 1500 ° C), it has relatively toughness. Due to this heating temperature, the scum moves to the scum reservoir without solidifying during the movement of the exhaust scum conduit. Although the molten metal surface is not shown in the figure, it is kept at a constant height by the molten metal level measuring sensor using a CCD camera and the method of controlling the pouring flow rate of the nozzle part. There is no need to move up and down to adjust.

[0010]

1 and 2, two cooling drums 1 and 1'having different rotation directions are horizontally arranged side by side, and two side dams 2 and 2 are provided on the end faces of the cooling drums 1 and 1 '. ′ Is pressed to define the hot water pool. The seal cover wall 6 at the upper part of the pool holds a space by contacting the side dams 2 and 2 ', the cooling drums 1 and 1'and the nozzle 7, and is inert by the inert gas flowing from the seal gas pipe 16. Form a gas atmosphere. The exhaust scum conduit 10 is held by a fixed seal cover wall 6 having an inner diameter of 10 mm, and is arranged so that the suction port 24 becomes substantially horizontal at the molten metal level position during casting. The conduit 10 is covered with a metal rope 9 on the outer skin. The outside of the scum is covered with a heater so that it is heated to a high temperature (for example, 1300 ° C to 1500 ° C) at which scum does not solidify during use. The outside is covered with an insulating heat insulating material. A part of the conduit 10 has a scum reservoir 14 having a large flow passage cross-sectional area so as not to flow into the vacuum pump. A filter 25 can be provided in the exhaust pipe.

At the start of casting, with the exhaust scum conduit 10 and the scum reservoir 14 preheated to 1300 ° C to 1500 ° C, the molten metal in the tundish 8 is poured through the nozzle 7 (a partially enlarged view is shown in Fig. 3). Then, the cooling drums 1, 1'are rotated. Immediately after casting, the level of the molten metal 4 is controlled to a fixed position. Scum generation is small at the beginning of pouring due to the effect of the seal gas, but the scum 5 increases with the passage of time. The width from end to end of the nozzle discharge port 21 is W
Since it is narrower than _N and the width W _D of the cooling drums 1, 1 ′, the flow on the surface of the molten metal is formed so that the shaft end is directed from the central part, and the scum 5 rides on the main flow to the shaft end direction. Move to. Further, since there is the scum weir 20, there is no flow to the cooling drum 1, 1'side. The scum 5 flows into the suction port 24 by the flow of gas that also flows into the suction port 24 by the exhaust gas activated after the start of pouring. The exhaust scum conduit 10 has a suction port 2
Since 4 is arranged so as to be partially immersed with respect to the level of the molten metal, it will block the flow path even if the amount of scum floating on the molten metal is relatively small, and as soon as it becomes blocked The pressure causes the scum 10 to be guided through the conduit to the scum reservoir 14. By repeatedly inflowing and closing the scum 5, the scum on the surface of the molten metal is removed without depositing on the surface of the molten metal.

[0012]

According to the twin-drum type continuous casting apparatus of the present invention, scum is removed before depositing on the molten metal surface, and scum is formed without being caught on the surface of the cooling drum. You can get a piece.

[Brief description of the drawings]

FIG. 1 is a partial vertical sectional view of a twin-drum type continuous casting apparatus according to the present invention and an embodiment.

FIG. 2 is a transverse cross-sectional view taken along the plane XX ′ of FIG.

3 is a transverse cross-sectional view taken along the plane YY 'of FIG.

FIG. 4 is a conceptual diagram of a conventional continuous casting device.

[Explanation of symbols]

1, 1 '... Cooling drum 2, 2' ... Side weir 3 ... Side weir heater 4 ... Molten metal 5, 5 '... Scum 6 ... Seal cover wall 7 ... Pouring nozzle 8 ... Tundish 9 ... Metal rope 10 ... Exhaust scum conduit 11 ... Heater 12 ... Insulation material 14 ... Scum reservoir 16 ... Seal gas pipe 17 ... Heater lead wire 20 ... Scum weir 21 ... Nozzle discharge port 22 ... Scum weir holder 23 ... Seal gas outlet 24 ... Suction port 25 ... Filter 30, 30 ′ ・ ・ ・ Molten metal flow 31, 31 ′ ・ ・ ・ Solidified shell 32 ・ ・ ・ Slab

Claims (2)

[Claims] 1. A pair of cooling drums rotating in opposite directions, a pair of side dams slidably contacting both ends of the drums, and a pool of water defined by the cooling drum and the side dams from the atmosphere. A twin-drum type continuous casting apparatus consisting of a seal cover having a seal gas supply means for shutting off, a pair of scum weirs parallel to the cooling drum in the molten metal pool and having a tip immersed in molten metal, A twin-drum type continuous casting apparatus comprising means for sucking and removing scum accumulated between the scum weirs. 2. A scum removing means, one end of which is immersed in a molten metal, the other end of which is connected to a scum reservoir, and a discharge scum conduit having a heating means, and which is connected to the discharge scum conduit and connected to an external suction means. A twin-drum type continuous casting device characterized by a scum reservoir.