JP4424164B2 - Sealing device for twin roll casting machine - Google Patents

Description

  The present invention relates to a sealing device for a twin roll casting machine.

  FIG. 2 shows an example of a twin roll casting machine, which includes a pair of cooling rolls 1 arranged horizontally and a pair of side weirs 2 attached to the cooling roll 1.

  The cooling roll 1 is configured such that cooling water flows through the roll 1 and the roll gap G can be adjusted in accordance with the thickness of the strip 3 to be produced.

  Further, the rotation direction and speed of the cooling roll 1 are set so that each outer peripheral surface moves from the upper side toward the roll gap G at a constant speed.

  One side weir 2 is in surface contact with one end of each cooling roll 1, and the other side weir 2 is in surface contact with the other end of each cooling roll 1, and is surrounded by the cooling roll 1 and the side weir 2. The transition piece 4 is arranged above the space to be in surface contact with the upper end of the side weir 2.

  The transition piece 4 is incorporated so that the molten metal supply nozzle 5 is located immediately above the roll gap G, and the molten metal is directed from the molten metal supply nozzle 5 to a space surrounded by the cooling roll 1 and the side weir 2. Is supplied, a molten metal reservoir 6 is formed.

  That is, when the molten metal pool 6 is formed and the cooling roll 1 is rotated while removing the heat by circulation of the cooling water, the molten metal is solidified on the outer peripheral surface of the cooling roll 1, and the strip 3 is directed downward of the roll gap G. Is sent out.

  In such a twin roll casting machine, a cover that covers the molten metal pool 6 is provided and an inert gas is fed into the cover to prevent the molten metal from being oxidized.

  In addition, the rotating body around which the woven fabric is wound is disposed so as to contact the outer surface of the cover as described above and the entire length in the axial direction of the outer peripheral surface of the cooling roll 1, and the woven fabric suppresses the intrusion of air into the cover. There has been proposed such a hot water cover (for example, see Patent Document 1).

Normally, nitrogen is used as the inert gas sent into the cover, but when the strip 3 is made thin, argon with relatively low thermal conductivity is mixed with nitrogen and sent into the cover. The heat of the molten metal is not easily transmitted to the cooling roll 1 and the increase in the outer peripheral surface temperature of the cooling roll 1 is suppressed, and the plate can be obtained without causing breakage due to poor formation of the solidified shell without particularly reducing the roll rotation speed. A thin strip 3 can be obtained.
Japanese Patent No. 2760695

  However, even if the inside of the cover is replaced with a nitrogen atmosphere from a pure nitrogen atmosphere, it takes 10 minutes or more for the temperature of the outer peripheral surface of the cooling roll 1 to decrease.

  This phenomenon accompanies the atmosphere as if the atmosphere is entangled with the texture (regularly arranged irregularities having a size of several tens of μm) formed on the outer peripheral surface of the cooling roll 1 when the cooling roll 1 rotates. This is because the nitrogen-containing nitrogen is difficult to touch.

  Moreover, in the thing of patent document 1, since the rotation direction of a rotary body is opposite to the cooling roll 1 which the rotary body contact | abuts seeing from the axial direction, air | atmosphere is pinched | interposed between a rotary body and the cooling roll 1. FIG. As a result, the accompanying air to the cooling roll 1 is promoted.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a twin-roll casting machine sealing device that can suppress the accompanying air to the cooling roll.

  In order to achieve the above object, the present invention provides a transition piece positioned above a molten metal pool formed between cooling rolls, and extends in the same direction as the cooling roll and below the transition piece on the opposite side of the molten metal pool. A cylindrical brush that can rotate in contact with each other over the entire length in the axial direction of the outer peripheral surface of the cooling roll, a first cowling that is connected to the transition piece and covers the cooling roll between the transition piece and the brush, A second cowling that surrounds a portion of the cowling that is not in contact with the cooling roll of the brush, a third cowling that is continuous with the second cowling and covers the cooling roll below the brush, and a transition piece And an outlet for sending seal gas between the cooling rolls.

  In the present invention, the seal gas delivered from the outlet is guided by the first, second, and third cowlings covering the cooling roll and the brush so as to go backward in the cooling roll rotation direction.

  In addition to this, the brush rotates in the same direction as the cooling roll with which the brush is in contact, or the speed of the seal gas flowing along the outer peripheral surface of the cooling roll exceeds the absolute value of the peripheral speed of the cooling roll. Do it.

  According to the sealing device for a twin roll casting machine of the present invention, the following excellent effects can be obtained.

  (1) The first, second, and third cowlings that cover the cooling roll and the brush guide the seal gas delivered from the outlet so as to reverse the rotation direction of the cooling roll. Can be suppressed.

  (2) Further, if the brush is rotated in the same direction as the cooling roll, or if the speed of the sealing gas exceeds the absolute value of the peripheral speed of the cooling roll, the accompanying air to the cooling roll is more effective. Can be suppressed.

  (3) Therefore, when the space above the molten metal pool is replaced with a nitrogen atmosphere containing pure nitrogen, the temperature of the outer peripheral surface of the cooling roll decreases in a shorter time than before, and the space is When the nitrogen atmosphere is replaced with a pure nitrogen atmosphere, the temperature of the outer peripheral surface of the cooling roll rises in a short time, so that strips having different plate thicknesses can be efficiently produced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of an embodiment of a sealing device for a twin roll casting machine according to the present invention. In the figure, the same reference numerals as those in FIG. 2 denote the same parts.

  This sealing device for a twin roll casting machine includes a cylindrical brush 7 extending in parallel with the cooling roll 1 and capable of rotating, an outlet 8 for discharging a sealing gas S such as pure nitrogen or argon-containing nitrogen, and each cooling roll 1. The first cowling 9, the second cowling 10, and the third cowling 11 that form a flow path for the seal gas S are provided.

  The brush 7 is disposed below the transition piece 4 so as to be in contact with the entire length of the outer peripheral surface of each cooling roll 1 in the axial direction from the opposite side of the molten metal reservoir 6, and is viewed from the axial direction by a driving mechanism such as a motor. 7 can rotate in the same direction as the cooling roll 1 with which it abuts.

  The outlet 8 is attached to the lower surface of the transition piece 4 so as to be positioned right above each cooling roll 1.

  The first cowling 9 is connected to the lower surface of the transition piece 4 and covers the outer peripheral surface and the peripheral edge portion of the cooling roll 1 between the transition piece 4 and the brush 7.

  The distance between the first cowling 9 and the outer peripheral surface of the cooling roll 1 is set in the range of 5 mm to 10 mm.

  The second cowling 10 is connected to the first cowling and surrounds a portion of the brush 7 that is not in contact with the cooling roll 1 and covers the outer peripheral surface and the peripheral edge of the cooling roll 1 located in the vicinity thereof. .

  The distance between the second cowling 10 and the outer peripheral portion of the brush 7 is set to 10 mm or less so that dust does not enter the first cowling 9 side by the rotation of the brush 7.

  The third cowling 11 is connected to the second cowling 10 and covers the outer peripheral surface and the peripheral edge portion of the cooling roll 1 below the brush 7.

  The interval between the third cowling 11 and the outer peripheral surface of the cooling roll 1 is set equal to or less than three times the interval between the first cowling 9 and the outer peripheral surface of the cooling roll 1 described above.

  Further, the length of the third cowling 11 in the circumferential direction of the cooling roll is set to 50 mm or more so that the seal gas S delivered from the outlet 8 is filled to the outlet portion of the third cowling 11, and the atmosphere is Do not enter the inside of the third cowling 11.

  The sum of the amounts of the seal gas S delivered from the two outlets 8 is the absolute value of the speed of the seal gas S flowing between the first cowling 9 and the cooling roll 1 and the peripheral speed of the cooling roll 1 (2 m / sec). It is trying to exceed.

  For example, the distance between the first cowling 9 and the outer peripheral surface of the cooling roll 1 (coiling roll interval) is 10 mm, the length of the cooling roll 1 (total roll length) is 1350 mm, and the amount of the seal gas S delivered from the two outlets 8 Assuming that the sum (gas discharge amount) is 150 cubic meters per minute, the speed (gas flow rate) of the seal gas S flowing between the first cowling 9 and the cooling roll 1 is about 93 meters per minute due to the following relationship: .

  Gas flow rate = Gas discharge rate / Number of rolls x Roll length x Cowling roll gap

  That is, the seal gas S delivered from the outlet 8 by the first, second, and third cowlings 9, 10, 11 covering the cooling roll 1 and the brush 7 exceeds the absolute value of the peripheral speed of the cooling roll 1 and is cooled. In addition to guiding the roll 1 in the direction of rotation of the roll 1 and rotating the brush 7 in contact with the cooling roll 1 in the same direction as the cooling roll 1, it is possible to effectively suppress the accompanying air to the cooling roll 1. it can.

  Thereby, when replacing between the molten metal reservoir 6 and the transition piece 4 from a pure nitrogen atmosphere to an argon-containing nitrogen atmosphere, the temperature of the outer peripheral surface of the cooling roll 1 is lowered in a shorter time compared to the conventional case, and conversely, the molten metal reservoir 6 Even when replacing the transition piece 4 between the argon-containing nitrogen atmosphere and the pure nitrogen atmosphere, the outer peripheral surface temperature of the cooling roll 1 rises in a short time, so that strips of different thickness can be produced efficiently. Is possible.

  The sealing device for a twin roll caster of the present invention is not limited to the above-described embodiment, and it is needless to say that changes can be made without departing from the gist of the present invention.

  The sealing device for a twin roll caster of the present invention can be applied to the production of various metal strips including steel.

It is a conceptual diagram which shows an example of embodiment of the sealing apparatus for twin roll casting machines of this invention. It is a conceptual diagram which shows an example of the conventional twin roll casting machine.

Explanation of symbols

1 Cooling Roll 4 Transition Piece 6 Molten Pool 7 Brush 8 Outlet 9 First Cowling 10 Second Cowling 11 Third Cowling

Claims (3)

  A transition piece located above the molten metal pool formed between the cooling rolls, and extending in the same direction as the cooling roll and extending from the opposite side of the molten metal pool to the entire axial direction of the outer circumferential surface of the cooling roll below the transition piece. A cylindrical brush that can rotate in contact with each other, a first cowling that is connected to the transition piece and covers the cooling roll between the transition piece and the brush, and is connected to the first cowling and is connected to the cooling roll of the brush. The second cowling that surrounds the non-contact portion, the third cowling that is connected to the second cowling and covers the cooling roll below the brush, and sends the sealing gas toward the transition piece and the cooling roll A sealing device for a twin roll casting machine, characterized by comprising an outlet.   The sealing device for a twin roll casting machine according to claim 1, wherein the rotation direction of the brush is set to be the same as that of the cooling roll in contact with the brush when viewed from the axial direction.   3. The twin according to claim 1, wherein the speed of the seal gas sent from the outlet and flowing between the first cowling and the cooling roll is set to exceed the absolute value of the peripheral speed of the cooling roll. Seal device for roll casting machine.

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