TW201731608A - Casting equipment for steel continuous casting process - Google Patents

Abstract

A casting equipment for steel continuous casting process includes a ladle, a tundish, an air ring and a flow guider. The ladle is to hold molten steel. The tundish is to distribute molten steel from the ladle to undertake the continuous casting of molten steel. The air ring is surrounded about a connection interface between the ladle and the tundish. The air ring includes several air outlets in its inner surfaces to output obtuse gas. The flow guide includes a ring body and several retaining ribs. The flow guide is installed within a central hollow section of the air ring and aligned with the air outlets. The ribs extending from the ring body are to be put upon the air ring.

Description

Steelmaking continuous casting process casting device

This invention relates to a metal casting apparatus, and more particularly to a casting apparatus for a steelmaking continuous casting process.

In the continuous casting process of steelmaking, the molten steel is transferred from the ladle to the steel distributor, and a long casting nozzle or a casting pipe is used. In the casting process, an inert gas (for example, argon gas) is introduced into the pipe. ) Prevent the molten steel from being exposed to air oxidation, but if the airtight operation is not good, the refined molten steel will be contaminated.

Generally, in the continuous casting and casting operation, the operator will try to reduce the gap between the bottom of the steel drum and the casting pipe to improve the air tightness. However, in actual operation, it is limited by the angle of view, which may not be close to each other and cause a gap to further contaminate the molten steel. Nitrogen or reoxygenation. In addition, because of the safety considerations in operation, when the bottom of the ladle is too close to the casting pipe, it is easy to collide and the molten steel distributor is dumped. Therefore, the ladle should not be too close to the casting pipe.

In view of the above problems, steel mills need better methods to solve the problem of poor airtight operation, thereby effectively reducing the problem of molten steel pollution and re-reduction or re-oxygenation.

Accordingly, one aspect of the present invention is to provide a steelmaking continuous casting process casting apparatus which is a solution for poor airtight operation during continuous casting and casting operations, thereby producing a steel material having a low nitrogen recovery or reoxygenation.

According to the above aspect of the invention, a steelmaking continuous casting process casting apparatus is provided, which comprises a steel ladle, a molten steel distributor, an air flow output ring and an air flow retaining ring. The steel drum is used to hold molten steel. The molten steel distributor is connected to the steel ladle to receive the molten steel for continuous casting. The airflow output ring surrounds the connection interface between the steel ladle and the molten steel distributor. The inner wall of the airflow output ring has a plurality of air outlets, and the airflow output ring is used for introducing the blunt gas through the air outlets. The air flow retaining ring includes a ring body and a plurality of hanging pieces. The ring body is placed in the hollow region of the airflow output ring and its position is aligned with the air outlet holes. A plurality of pendants extend from the airflow stop ring and are connected across the airflow output ring.

According to an embodiment of the invention, the average spacing of the ring body from the inner wall of the airflow output ring is between 10 mm and 30 mm.

According to an embodiment of the invention, the airflow output ring further includes an inner passage and an air inlet, and the inner passage, the air inlet, and the air outlets communicate with each other.

According to an embodiment of the invention, the air inlet aperture is located outside the airflow output ring.

According to an embodiment of the invention, the air flow retaining ring is a metal retaining ring.

According to an embodiment of the invention, there is a below the ladle The long casting nozzle has a casting tube above the molten steel distributor, and the long casting nozzle is placed in the casting tube to form a connecting interface.

According to an embodiment of the invention, the ring body has the same thickness as the airflow output ring.

According to an embodiment of the invention, the thickness of the ring body is less than the thickness of the airflow output ring.

According to an embodiment of the invention, the thickness of the ring body is greater than the thickness of the airflow output ring.

According to an embodiment of the invention, the pendants extend from the outer side wall of the top end of the ring body.

By applying the steelmaking continuous casting process casting device of the invention, the airflow field in the airflow output ring and the steelmaking casting pipe can be changed, and the blown out air is formed into an upward flow field by an airflow retaining ring, and the gap is directed to When the outside is discharged, the positive pressure is maintained in the casting pipe, and the outside air is prevented from entering, thereby effectively improving the airtightness in the presence of the gap. The use of this device allows the operator to have greater operational flexibility, without the need to hold the steel drum tightly to the casting pipe, avoiding collisions or causing the molten steel distributor to dump, while maintaining a certain airtightness to maintain the quality of the molten steel. .

100‧‧‧Steelmaking and continuous casting process casting device

102‧‧‧Steel drum

104‧‧‧Long casting nozzle

106‧‧‧ gap

108‧‧‧Airflow output ring

108a‧‧‧Air intake

108b‧‧‧Internal passage

108c‧‧‧ Vents

110‧‧‧casting pipe

112‧‧‧Steel Liquid Dispenser

114‧‧‧ casting nozzle

116‧‧‧ air retaining ring

116a‧‧‧Act

116b‧‧‧Pendant

117‧‧‧ spacing

T‧‧‧ thickness

T‧‧‧thickness

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; Continuous casting process casting device; 2 is a (half) airflow output ring according to an embodiment of the invention; [FIG. 3] shows a matching airflow stop ring according to an embodiment of the invention (half Airflow output ring; [Fig. 4] is a schematic diagram of a gas flow field simulated according to an embodiment of the present invention; [Fig. 5] is a schematic view of a gas flow field simulated according to another embodiment of the present invention; And [Fig. 6] is a comparison diagram of oxygen concentration data according to two embodiments of the present invention.

In order to solve the above problems, the present invention proposes a steelmaking continuous casting process casting device having a gas flow field in a casting pipe, which can maintain a good aeration effect in the presence of a gap between the steel ladle and the steel liquid distributor. The blunt gas blown out by the airflow output ring is formed by an airflow retaining ring to form an upward flow field, and flows out from the gap to maintain a positive pressure in the casting pipe, so that the outside air can not enter, thereby effectively improving the gap. Air tightness when present.

The use of the steelmaking continuous casting process casting device allows the casting operator to have greater operational flexibility, without the need to hold the steel drum tightly to the casting pipe, avoiding collision or causing the molten steel distributor to dump, and at the same time maintaining a certain gas. Density to maintain the quality of molten steel.

Please refer to FIG. 1 , which illustrates a steelmaking continuous casting process casting apparatus according to an embodiment of the present invention. Steelmaking continuous casting process casting device 100 A steel drum 102, a molten steel distributor 112, and an airflow output ring 108 are included. The steel drum 102 is used to hold molten steel. The molten steel distributor 112 is connected to the ladle 102 to receive the molten steel and continuously cast by the casting nozzle 114 below it. The airflow output ring 108 surrounds the connection interface of the ladle 102 to the molten steel distributor 112. The above-mentioned "connection interface" is composed of a casting nozzle 110 in which the long casting nozzle 104 of the ladle 102 is placed in the molten steel distributor 112. As shown in the figure, there is a long casting nozzle 104 below the ladle 102, and a casting pipe 110 above the molten steel distributor 112, which can constitute the above-mentioned "connection interface". However, the connection interface between the ladle and the steel liquid distributor is not limited thereto, and any design that can transfer the molten steel of the ladle to the molten steel distributor can be applied.

Please refer to [Fig. 2], which shows a (half) airflow output ring according to an embodiment of the present invention. In order to more clearly illustrate the overall structure of the airflow output ring 108, [Fig. 2] only shows the truncated (half) airflow output ring, and the complete airflow output ring 108 is a ring shape. The airflow output ring 108 is used to introduce the blunt gas into the connection interface of the above-mentioned steel ladle and the steel liquid distributor. The inner wall of the airflow output ring 108 has a plurality of air outlets 108c through which an indirect air (for example, argon gas) is introduced, so that the blunt gas can surround the connection interface between the steel ladle and the molten steel distributor. In turn, the function of blocking air ingress is achieved. The airflow output ring 108 further includes an inner passage 108b and an air inlet 108a. The inner passage 108b extends through the entire airflow output ring 108, and the inner passage 108b, the air inlet 108a, and the air outlets 108c communicate with each other. The air outlet 108c is located on the outer wall of the airflow output ring 108 to facilitate the connection of the blunt gas inlet pipe. Therefore, when the blunt gas is injected from the air inlet hole 108a, it is transmitted to the air outlet holes 108c through the inner passage 108b.

Please refer to [FIG. 3], which illustrates a (half) airflow output ring with an airflow stop ring according to an embodiment of the invention. In order to maximize the effect of the airflow output ring 108, an airflow stop ring 116 is also used in conjunction with the airflow output ring 108. The air flow stop ring 116 includes a ring body 116a and a plurality of hanging pieces 116b. The ring body 116a is placed in the hollow region of the airflow output ring 108, and its position is aligned with the air outlet holes 108c of the inner wall of the airflow output ring 108, so that the airflow output from the air outlet 108c directly meets the ring body 116a. The plurality of hangers 116b extend from the ring 116a and are coupled across the airflow output ring 108 (ie, across the top surface of the airflow output ring 108) to position the ring 116a within the hollow region of the airflow output ring 108. The tabs 116b extend from the outer side wall of the top end of the ring body 116a and the outer end of the ring body 116a is positioned in the airflow output ring 108. The top end of the ring body 116a is substantially aligned with the top end of the airflow output ring 108. of. The thickness (t) of the ring body 116a may be greater than, equal to, or less than the thickness (T) of the airflow output ring 108 as long as the position of the ring 116a is aligned with the vents 108c of the airflow output ring 108. In this embodiment, the airflow retaining ring may be a metal retaining ring, but is not limited thereto.

When the airflow stop ring 116 is placed in the hollow region of the airflow output ring 108, its ring body 116a and the inner wall of the airflow output ring 108 should maintain a spacing 117. The pitch 117 can be adjusted according to the strength of the air outlets 108c, but the average value of the pitch 117 is preferably 10 mm to 30 mm.

Please refer to [FIG. 4], which is a schematic diagram of a gas flow field simulated according to an embodiment of the present invention. This simulated gas flow field is simulated with a gas flow field made by the gas flow output ring 108 that does not match the gas flow stop ring 116. Since the airflow stop ring 116 is not added, it can be found that when there is a gap 106, the airflow is lost. The inner wall surface of the outlet ring 108 creates a downward flow field which tends to form a negative pressure zone at the gap 106 and tends to draw in outside air.

Table 1 below shows the oxygen concentration in the casting tube measured by the gas flow field simulated by the above-mentioned [Fig. 4] in different gaps (in mm) and the protective atmosphere (nitrogen) flow rate (unit LPM). (%) change list. It can be seen from the trend of Table 1 that when the gap 106 is larger than 40 mm, the oxygen concentration is about 6% and has no correlation with the flow rate of the protective atmosphere; and when the gap 106 is between 10 mm and 30 mm, the oxygen concentration in the casting tube (%) can be seen. In contrast to the protective atmosphere flow (LPM), this situation confirms that the larger the protective atmosphere flow rate, the more the outer boundary air is drawn by the gap 106. This and the conventional "the greater the flow rate of the protective atmosphere, the lower the air concentration (such as oxygen)" is contrary to the technical concept. When the gap 106 is 0 mm, since the atmosphere is well protected, the oxygen concentration is maintained at less than 0.1%, but this condition is difficult to achieve under actual operating conditions, and has no reference value. The above experimental results show that in the presence of the gap 106, if only the airflow output ring 108 is wrapped around the circumference of the casting pipe, under normal operating conditions (ie, when the gap 106 is between 10 mm and 30 mm), the atmosphere protection effect in the casting pipe is Poor, steel liquid is very prone to nitrogen or reoxygenation pollution.

Please refer to [FIG. 5], which illustrates another implementation according to the present invention. A schematic diagram of the gas flow field simulated by the example. This gas flow field simulation is simulated with the gas flow field made by the airflow output ring 108 of the airflow stop ring 116. Since the airflow output from the air outlet 108c of the airflow output ring 108 directly hits the airflow stop ring 116 to generate an upward flow field, an outward airflow (positive pressure) can be generated at the gap 106 to prevent outside air from being sucked in.

Tables 2 and 3 below show the gas flow field simulated by the above embodiment of Fig. 5 in different gaps (units of mm), spacing (units of mm), and protective atmosphere (nitrogen) flow (units of LPM). A list of changes in oxygen concentration (%) in the cast tube was measured. The protective atmosphere (nitrogen) flow rate in Table 2 was 600 LPM, and the protective atmosphere (nitrogen) flow rate in Table 3 was 1000 LPM. The "gap" in Tables 2 and 3 refers to the gap 106 in [Fig. 5] (i.e., the gap between the ladle 102 and the airflow output ring 108), and the spacing refers to the distance 117 in the [Fig. 3] (i.e., the ring body). 116a is spaced from the inner wall of the airflow output ring 108). It can be seen from the test results of Tables 2 and 3 that the spacing 117 has little effect on the internal flow field or oxygen concentration (%) in the casting pipe in the range of 10 mm to 30 mm; and after the airflow blocking ring 116 is used, the gap 106 can be maintained at 20 mm. Under the following conditions, the oxygen concentration in the casting tube was less than 1%, and the experimental data showed that it was consistent with the previous simulation results.

Please refer to [Fig. 6], which is a comparison diagram of oxygen concentration data according to two embodiments of the present invention. Figure 6 is a comparison diagram of the oxygen concentration data (%) obtained by the embodiment of the air flow output ring 108 of "having" and "none" associated with the air flow stop ring 116 under the same conditions (same gap 106 and gas flow rate). It can be seen from the figure that the addition of the airflow stop ring 116 can effectively reduce the oxygen concentration by 1~2%, which will allow the field operators to have greater operational freedom, and the same quality can ensure the quality of the cast steel.

By applying the steelmaking continuous casting process casting device of the invention, the airflow field in the airflow output ring and the steelmaking casting pipe can be changed, and the blown out air is formed into an upward flow field by an airflow retaining ring, and the gap is directed to When the outside is discharged, the positive pressure is maintained in the casting pipe, and the outside air is prevented from entering, thereby effectively improving the airtightness in the presence of the gap. The use of this device allows the operator to have greater operational flexibility, without the need to hold the steel drum tightly to the casting pipe, avoiding collisions or causing the molten steel distributor to dump, while maintaining a certain airtightness to maintain the quality of the molten steel. .

While the invention has been described above in terms of several embodiments, it is not intended to limit the scope of the invention, and the invention may be practiced in various embodiments without departing from the spirit and scope of the invention. The scope of protection of the present invention is defined by the scope of the appended claims.

100‧‧‧Steelmaking and continuous casting process casting device

102‧‧‧Steel drum

104‧‧‧Long casting nozzle

106‧‧‧ gap

108‧‧‧Airflow output ring

110‧‧‧casting pipe

112‧‧‧Steel Liquid Dispenser

114‧‧‧ casting nozzle

Claims (10)

A steelmaking continuous casting process casting device comprises: a steel ladle for containing molten steel; a steel liquid distributor connected to the steel ladle for continuous casting of molten steel; and an air flow output ring surrounding a connection interface between the steel ladle and the molten steel distributor, the inner wall of the air flow output ring has a plurality of air outlets, the air flow output ring is used for introducing the blunt gas through the air outlets; and an air flow blocking ring comprises: a ring body disposed in a hollow region of the airflow output ring and positioned opposite the air outlet holes; and a plurality of pendant members extending from the ring body and bridging the airflow output ring. The steelmaking continuous casting process casting device according to claim 1, wherein the annular body and the inner wall of the airflow output ring have an average spacing of 10 mm to 30 mm. The steelmaking continuous casting process casting apparatus of claim 1, wherein the airflow output ring further comprises an inner passage and an air inlet, the inner passage, the air inlet and the air outlets are in communication with each other. The steelmaking continuous casting process casting apparatus according to claim 1, wherein the air inlet hole is located at an outer wall of the airflow output ring. The steelmaking continuous casting process casting device according to claim 1, wherein the airflow retaining ring is a metal retaining ring. The steelmaking continuous casting process casting device according to claim 1, wherein the steel drum has a long casting nozzle under the steel ladle, and a casting pipe is arranged above the molten steel distributor, and the long casting nozzle is placed The casting tube forms the connection interface. The steelmaking continuous casting process casting apparatus according to claim 1, wherein the ring body has the same thickness as the airflow output ring. The steelmaking continuous casting process casting apparatus according to claim 1, wherein the ring body has a thickness smaller than a thickness of the airflow output ring. The steelmaking continuous casting process casting apparatus according to claim 1, wherein the ring body has a thickness greater than a thickness of the airflow output ring. The steelmaking continuous casting process casting apparatus according to claim 1, wherein the hanging pieces extend from a top end of the ring body perpendicular to an outer side wall of the ring body.