JP2010214414A - Twin roll type continuous casting machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a twin roll type continuous casting machine which can evade deterioration in the quality of the surface of a slab and the stop of casting caused by a cooling medium stuck to the surfaces of rolls. <P>SOLUTION: In the twin roll type continuous casting machine 10, a molten steel 14 is fed to a space between the circumferential faces of a pair of rolls 11a, 11b rotating in reverse directions each other, and a slab 15 obtained by press-welding a solidified shell solidified at the circumferential face of each roll is pulled out from the space between the circumferential faces of the rolls. The machine is provided with cooling medium removing devices 18a, 18b which sprays air toward the circumferential faces and the edge faces of the pair of rolls and removes water stuck to the circumferential faces and the edge faces of the rolls. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a twin-roll continuous casting machine capable of contributing to stable casting.

  Conventionally, twin roll type continuous casting machines have been mainly used for casting thin steel plates (strips). Therefore, the equipment etc. which cool a steel plate directly under a roll are not held, but the internal cooling device which cools a roll from the inside of a roll was equipped, for example, which cools a roll heated (for example, 600-700 ° C) with a molten steel. .

  By the way, recently, there is a case where a thick slab (including an unsolidified portion) is cast by a twin roll type continuous casting machine. In such a case, an unsolidified portion is included inside the slab, Since it is necessary to cool the slab drawn out from the roll immediately below, it is essential to provide a cooling spray or the like for cooling the slab directly below the roll.

  However, when the cooling medium (water) sprayed by a cooling spray or the like is in contact with the molten steel in a state of adhering to the roll surface, (1) the vaporized water causes bubbling in the molten steel, and the slab surface quality deteriorates. (2) The bubbling generated on the roll surface induces a contact failure between the roll surface and the slab, obstructs heat removal from the roll and hinders the growth of the slab, and (3) sealability of the drum end face When water adheres to the side weir installed for the purpose and the roll end surface in contact with the side weir, the problem of the side weir material softening and deteriorating and the sealing performance becomes worse, (4) Inside the side weir material When the invading water vaporizes and generates bubbling, there is a problem of damaging the side weir. Since the problems (1), (2), (3), and (4) are problems that may lead to casting stop, it is necessary to provide a device for removing the cooling medium (water).

  Therefore, Patent Document 1 proposes an external cooling device using a cooling medium for the purpose of providing a roll cooling method that is inexpensive and easy to install in a twin roll type continuous casting machine, and the cooling medium attached to the roll surface at this time is proposed. A technique for attaching a cooling medium removing device for removing the water is also disclosed.

  That is, as shown in FIG.8 and FIG.9, the twin roll type continuous casting machine 100 supplies the molten steel 103 from the pouring nozzle 102 between the roll peripheral surfaces of a pair of rolls 101a and 101b rotating in opposite directions, The slab 104 formed by press-contacting the solidified shell solidified on the peripheral surfaces of the rolls 101a and 101b is drawn out between the peripheral surfaces of the rolls.

  Further, reference numeral 105 shown in FIG. 8 denotes a side weir that slides with the twin roll end face that rotates synchronously and seals the end face side of the molten steel 103. When a slab grows on the surface of the side weir in contact with the molten steel, it will combine with the slab grown on the roll surface, hindering the problem of inhibiting the rotation of the roll or the contact between the slab formed on the roll surface and the roll. Since there is a problem, the side weir material is made of a refractory material having low heat conduction for the purpose of suppressing the growth of the slab.

  In addition, external water cooling devices (external cooling devices) 106a and 106b for cooling the rolls by spraying water (cooling medium) toward the peripheral surfaces of the rolls are installed below the peripheral surfaces of the rolls 101a and 101b. Above the peripheral surfaces of the rolls 101a and 101b, draining devices (cooling medium removing devices) 107a and 107b for blowing external air toward the peripheral surfaces of the rolls and removing external cooling water adhering to the peripheral surfaces of the rolls are installed. .

  Therefore, it is conceivable to apply the draining device (cooling medium removing device) 107a, 107b to a twin roll type continuous casting machine provided with a cooling spray or the like for cooling the slab immediately below the roll.

JP 2006-136889 A

  However, in the cooling medium removing device (water draining device) disclosed in Patent Document 1, the range for removing the cooling medium is limited to the roll peripheral surface (the circumferential direction in which the roll and molten steel are in contact). When the cooling medium adheres to the end face of the roll, the cooling medium is not removed and reaches the contact portion between the side weir and the end face of the roll while remaining attached to the end face of the roll.

  Therefore, the cooling medium adhering to the roll end face is absorbed into the side weir, the side weir material softens and deteriorates, and the sealing performance deteriorates. Further, the cooling medium absorbed in the side weir vaporizes and generates bubbling. However, problems such as deterioration of the slab surface quality and missing side weirs due to bubbling of the vaporized cooling medium still remain.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a twin-roll continuous casting machine that can avoid deterioration of slab surface quality and stop of casting due to a cooling medium adhered to the roll surface.

In order to achieve the above object, a twin roll continuous casting machine according to the present invention comprises:
A twin-roll continuous casting machine that supplies molten steel between the peripheral surfaces of a pair of rolls rotating in opposite directions, and draws out the cast slab formed by pressing the solidified shell solidified on the peripheral surfaces of each roll from between the peripheral surfaces of the rolls In
A cooling medium removing device is provided that blows gas toward the peripheral surface and end surface of the pair of rolls to remove the cooling medium adhering to the peripheral surface and end surface of the roll.

Also,
The injection direction of the external cooling medium supply device provided at least closest to the cooling medium removing device on the upstream side in the roll rotation direction is set to the external cooling medium injected from the external cooling medium supply device at least before the roll. The cooling medium attached to the peripheral surface is directed upstream in the roll rotation direction so as to be swept away upstream in the roll rotation direction.

Also,
A plate that mechanically removes the cooling medium adhering to at least the peripheral surface of the roll as a stage before the cooling medium removal surface of the roll passes through the cooling medium removal apparatus on the upstream side in the roll rotation direction of the cooling medium removal apparatus. It is characterized by providing a scraper.

Also,
The cooling medium removing device is a slit nozzle having two slits, and these two slits are arranged close to each other in the roll rotation direction.

Also,
The cooling medium removing apparatus is divided into a roll peripheral surface and an end surface.

  According to the twin-roll continuous casting machine of the present invention having the above-described configuration, the cooling medium adhering to the roll surface can be reliably removed over a wide range not only on the roll peripheral surface but also on the roll end surface. It is possible to prevent the deterioration of the sealing performance by preventing the deterioration of the sealing performance by preventing the deterioration of the sealing property and suppressing the bubbling due to the vaporization of the cooling medium.

  As a result, stable casting becomes possible, and casting stoppage due to missing side weirs or excessive bubbling is avoided.

It is a principal part front view of the twin roll type continuous casting machine which shows Example 1 of this invention. 1A is a view taken along the line AA in FIG. 1, and FIG. 1B is a cross-sectional view taken along the line BB in FIG. 1A. It is explanatory drawing of the cooling medium removal apparatus which shows Example 2 of this invention. It is a side view of the cooling medium removal apparatus which shows Example 3 of this invention. It is a principal part front view of the twin roll type continuous casting machine which shows Example 4 of this invention. It is a principal part front view of the twin roll type continuous casting machine which shows Example 5 of this invention. It is CC arrow line view of FIG. It is a principal part front view of the conventional twin roll type continuous casting machine. It is the DD arrow line view of FIG.

  Hereinafter, a twin roll type continuous casting machine according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a front view of an essential part of a twin roll type continuous casting machine showing Embodiment 1 of the present invention, FIG. 2 (a) is a view taken along arrow AA in FIG. 1, and FIG. 2 (b) is FIG. FIG.

  As shown in FIG. 1, the twin roll type continuous casting machine 10 of the present embodiment has a pair of rolls 11a and 11b that rotate in opposite directions close to each other, and both axial ends of these rolls 11a and 11b. Is partitioned by a side weir 12 that is in close contact with the roll end face.

  Then, under the rotation of the rolls 11 a and 11 b, the molten steel 14 is supplied via the pouring nozzle 13 to the internal space (hot water pool portion) formed surrounded by the rolls 11 a and 11 b and the side weir 12. The slab 15 formed by press-contacting the solidified shell solidified on the peripheral surfaces of the rolls 11a and 11b is drawn out between the peripheral surfaces of the rolls.

  In addition, cooling spray groups 16a and 16b for cooling the slab are installed directly below the rolls 11a and 11b to inject water (cooling medium) toward the surface of the slab 15 to cool the slab 15. A cooling spray group for cooling the rolls (external cooling) that sprays water (cooling medium) toward the roll surface (at least the peripheral surface) below the peripheral surfaces of the rolls 11a and 11b to cool the rolls 11a and 11b. Apparatus) 17a, 17b is installed. Instead of the cooling spray groups 17a and 17b for cooling the roll, an internal cooling device that cools the rolls 11a and 11b from the inside of the rolls 11a and 11b may be adopted.

  Furthermore, cooling medium removing devices 18a and 18b for removing water adhering to the roll surface by blowing air (gas) toward the roll surface are installed above the peripheral surfaces of the rolls 11a and 11b.

  As shown in FIGS. 2A and 2B, the cooling medium removing devices 18a and 18b are formed by slit nozzles having one slit 19 in the roll rotation direction (see FIG. 2B). The slits 19 are continuously formed in a gate shape in a side view so as to cover the peripheral surface and both end surfaces of each roll 11a, 11b (see FIG. 2A), and are also formed in a series in a gate shape. Air in the chamber 20 is blown toward the peripheral surfaces and end surfaces of the rolls 11a and 11b to remove water adhering to the peripheral surfaces and end surfaces of the rolls 11a and 11b.

  Pressurized air is supplied into the chamber 20 from an air supply source 21 such as a compressor. In addition, the length of the slit 19 extends to the entire length of the roll width at the peripheral surface portions of the rolls 11a and 11b, but at both end surface portions, the cooling medium contacting at least the side weir of the roll diameter can be removed. Set to range.

  Since it is configured in this manner, at the time of casting the slab 15 that is thick and includes an unsolidified portion, the slab 15 is cooled with water sprayed from the cooling spray groups 16a and 16b for cooling the slab, and a roll Each roll 11a, 11b is cooled with the water sprayed from the cooling spray groups 17a, 17b for cooling.

  At this time, splashed water from the cooling spray groups 16a and 16b for cooling the slab adheres to the peripheral surfaces and end faces of the rolls 11a and 11b, and spray water from the cooling spray groups 17a and 17b for cooling the rolls. Adhere to.

  And the water adhering to the peripheral surface and end surface of each roll 11a, 11b is blown from the cooling medium removing devices 18a, 18b installed downstream of the roll spraying cooling spray groups 17a, 17b in the roll rotation direction. Removed.

  In this way, according to the present embodiment, the water adhering to the surface of each roll 11a, 11b can be reliably removed over a wide range not only on the roll peripheral surface but also on the roll end surface. It is possible to prevent softening / deterioration and avoid deterioration of sealing performance, and suppress occurrence of bubbling due to water vaporization to avoid deterioration of slab surface quality.

  As a result, stable casting becomes possible, and casting stoppage due to missing side weirs 12 or excessive bubbling is avoided.

  FIG. 3 is an explanatory view of a cooling medium removing apparatus showing Embodiment 2 of the present invention.

  In this embodiment, the cooling medium removing devices 18a and 18b in Embodiment 1 are formed by slit nozzles having two slits 19a and 19b, and these two slits 19a and 19b are arranged close to each other in the roll rotation direction. It is an example. The other configuration is the same as that of the first embodiment, and a duplicate description is omitted.

  According to this, in addition to the same operations and effects as in the first embodiment, the two slits 19a and 19b are arranged close to each other in the roll rotation direction, so that the slit 19a as shown in the graph showing the pressure characteristics in the figure. , 19b has a positive pressure, and the positive pressure pushes back the water that has entered just below the nozzle, and the cooling medium removing performance is improved as compared with one slit 19 (see FIG. 2B). Is obtained.

  FIG. 4 is an explanatory view of a cooling medium removing apparatus showing Embodiment 3 of the present invention.

  In this embodiment, the cooling medium removing devices 18a and 18b in the first embodiment are used for the peripheral surfaces of the rolls 11a and 11b (see the chamber 20a and the air supply source 21a, slits not shown) and for the end surfaces (the chamber 20b and the air supply). In this example, the source 21b is divided into slits (not shown). The other configuration is the same as that of the first embodiment, and a duplicate description is omitted.

  According to this, since the cooling medium removing devices 18a and 18b are divided into those for the peripheral surface and for the end surface in addition to the same operations and effects as in the first embodiment, the respective slit widths and air flow rates (the chambers in the figure) 20a, 20b internal pressures P1 to P3) and the like can be individually adjusted, and the degree of freedom of the apparatus is increased, so that there is an advantage that the cooling medium can be removed stably and economically.

  FIG. 5 is a front view of an essential part of a twin-roll continuous casting machine showing Embodiment 4 of the present invention.

  In this embodiment, the spray direction of the cooling sprays 17a 'and 17b' provided closest to the cooling medium removing devices 18a and 18b in the cooling spray groups 17a and 17b for roll cooling in the first embodiment This is an example in which water sprayed from the cooling sprays 17a 'and 17b' is directed upstream in the roll rotation direction so that water previously adhered to the roll surface is pushed away upstream in the roll rotation direction. The other configuration is the same as that of the first embodiment, and a duplicate description is omitted.

  According to this, in addition to the same operations and effects as in the first embodiment, the water sprayed from the cooling sprays 17a ′ and 17b ′ forms a flow for pushing back the water adhering to the roll surface to the upstream side in the roll rotation direction. Since it becomes possible to suppress the entry of water to the downstream side in the roll rotation direction, there is an advantage that the water can be more reliably removed by the cooling medium removing devices 18a and 18b.

  FIG. 6 is a front view of an essential part of a twin-roll continuous casting machine showing Embodiment 5 of the present invention, and FIG. 7 is a view taken along the line CC in FIG.

  In this embodiment, the cooling medium removal surfaces of the rolls 11a and 11b are located immediately on the upstream side in the roll rotation direction of the cooling medium removal apparatuses 18a and 18b in the first and fourth embodiments. This is an example in which plate-shaped scrapers 22a and 22b for mechanically removing water adhering to the surfaces of the respective rolls 11a and 11b are provided as a stage before passing through the roller.

  In the illustrated example, the scrapers 22a and 22b are continuously formed in a gate shape in a side view so as to cover the circumferential surface and both end surfaces of each roll 11a and 11b (see FIG. 7), and the circumference of each roll 11a and 11b. Although water adhering to the surface and both end surfaces is roughly cut, only the peripheral surfaces of the rolls 11a and 11b may be roughly cut. The other configuration is the same as that of the first embodiment, and a duplicate description is omitted.

  According to this, in addition to the same operations and effects as in the first embodiment, the water attached to the peripheral surface and both end surfaces of each roll 11a, 11b is roughly cut by the scrapers 22a, 22b, so that it is installed on the downstream side thereof. Thus, it is possible to reduce the load on the cooling medium removing devices 18a and 18b, and it is possible to obtain an advantage that the cooling medium can be removed economically and stably.

  The present invention is not limited to the above embodiments, and the cooling medium removing devices 18a and 18b are installed in a plurality of stages in the roll rotation direction, or the slit nozzles are arranged on the roll surface without departing from the gist of the present invention. It goes without saying that various changes are possible, such as inclining upstream, or using a porous nozzle instead of the slit nozzle.

  The twin roll type continuous casting machine according to the present invention can be applied to a thin steel plate (strip) or a thick slab.

DESCRIPTION OF SYMBOLS 10 Twin roll type continuous casting machine 11a, 11b Roll 12 Side dam 13 Pouring nozzle 14 Molten steel 15 Slab 16a, 16b Cooling spray group 17a, 17b Cooling spray group 17a ', 17b' Cooling for roll cooling Spray 18a, 18b Cooling medium removing device 19, 19a, 19b Slit 20, 20a, 20b Chamber 21, 21b, 21b Air supply source 22a, 22b Plate-shaped scraper

Claims (5)

A twin-roll continuous casting machine that supplies molten steel between the peripheral surfaces of a pair of rolls rotating in opposite directions, and draws out the cast slab formed by pressing the solidified shell solidified on the peripheral surfaces of each roll from between the peripheral surfaces of the rolls In
A twin-roll continuous casting machine, comprising a cooling medium removing device that blows gas toward the peripheral surface and end surfaces of the pair of rolls to remove the cooling medium attached to the peripheral surfaces and end surfaces of the rolls.   The injection direction of the external cooling medium supply device provided at least closest to the cooling medium removing device on the upstream side in the roll rotation direction is set to the external cooling medium injected from the external cooling medium supply device at least before the roll. The twin roll continuous casting machine according to claim 1, wherein the cooling medium adhering to the peripheral surface is directed upstream in the roll rotation direction so as to flow away upstream in the roll rotation direction.   A plate that mechanically removes the cooling medium adhering to at least the peripheral surface of the roll as a stage before the cooling medium removal surface of the roll passes through the cooling medium removal apparatus on the upstream side in the roll rotation direction of the cooling medium removal apparatus. A twin-roll type continuous casting machine according to claim 1 or 2, further comprising a scraper having a shape.   4. The twin roll according to claim 1, wherein the cooling medium removing device is a slit nozzle having two slits, and these two slits are arranged close to each other in the roll circumferential direction. Type continuous casting machine.   5. The twin-roll continuous casting machine according to claim 1, wherein the cooling medium removing device is divided into a roll peripheral surface and an end surface.

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