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KR-20260067797-A - LANCE FOR BLOWING IN CONVERTER

KR20260067797AKR 20260067797 AKR20260067797 AKR 20260067797AKR-20260067797-A

Abstract

The disclosed blowing lance comprises: a lance body having a gas passage inside; a main nozzle located at the lower end of the lance body and open to the outside of the lance body in communication with the gas passage; a first sub-nozzle that is open to the outside of the lance body in communication with the gas passage, is located above the main nozzle, and extends at a first sub-angle of inclination with respect to the longitudinal axis of the lance body; and a second sub-nozzle that is open to the outside of the lance body in communication with the gas passage, is located above the first sub-nozzle, and extends at a second sub-angle of inclination with respect to the axis.

Inventors

  • 박봉환
  • 김경수
  • 엄창호
  • 이지아

Assignees

  • 현대제철 주식회사

Dates

Publication Date
20260513
Application Date
20241106

Claims (12)

  1. Lance body having a gas passage inside; A main nozzle located at the lower part of the lance body and open to the outside of the lance body in communication with the gas passage; A first sub-nozzle that is open to the outside of the lance body in communication with the above gas passage, is located above the main nozzle, and extends at a first sub-angle of inclination with respect to the longitudinal axis of the lance body; and A blowing lance characterized by including: a second sub-nozzle that is open to the outside of the lance body in communication with the above gas flow path, is located above the first sub-nozzle, and extends at a second sub-angle of inclination with respect to the axis.
  2. In Article 1, A blowing lance characterized by the fact that the size of the second sub-angle is larger than the size of the first sub-angle.
  3. In Article 2, A blowing lance characterized in that the size of the first sub-inclination angle is 19 to 21°.
  4. In Article 2, A blowing lance characterized in that the size of the second sub-inclination angle is 34 to 36°.
  5. In Article 1, A blowing lance characterized in that the first sub-nozzle above includes a tubular nozzle with a constant inner diameter along the longitudinal direction.
  6. In Article 1, A blowing lance characterized by the fact that the second sub-nozzle above includes a cone-shaped nozzle whose inner diameter increases as it moves away from the inlet and closer to the outlet.
  7. In Article 1, The above lance body is, The main nozzle block part in which the above main nozzle is formed, A sub-nozzle block portion located on the upper side of the main nozzle block portion and having the first sub-nozzle and the second sub-nozzle formed therein, A first cylindrical portion extending along the above axis and comprising one end connected to the main nozzle block portion and the other end connected to the sub nozzle block portion, and A blowing lance characterized by including a second cylindrical portion that extends along the above-mentioned axis and includes one end portion connected to the sub-nozzle block portion.
  8. In Article 7, A blowing lance characterized in that the diameter of the second cylindrical part is larger than the diameter of the first cylindrical part.
  9. In Article 8, A blowing lance characterized in that the shortest distance from the axis to the outlet of the second sub-nozzle is longer than the shortest distance from the axis to the outlet of the first sub-nozzle.
  10. In Article 7, A blowing lance characterized in that the distance between the main nozzle block and the sub nozzle block is 1.5 to 2.0 m (meter).
  11. In Article 1, A blowing lance characterized in that the inner diameter of the outlet of the second sub-nozzle is larger than the inner diameter of the outlet of the first sub-nozzle.
  12. In Article 1, The first sub-nozzle and the second sub-nozzle are each provided in multiple numbers, and A blowing lance characterized in that a plurality of first sub-nozzles and a plurality of second sub-nozzles are each arranged at equal intervals around the axis.

Description

Lance for Blowing in Converter The present invention relates to a blowing lance, and more specifically, to a blowing lance including a secondary combustion nozzle. The process of producing molten iron from a blast furnace by feeding it into a converter along with scrap and melting it to produce molten steel is called the steelmaking process. In the steelmaking process, the process of using a lance to blow oxygen to oxidize and remove impurities such as carbon, phosphorus, and sulfur is called blowing. If the efficiency of the blowing process is improved, a smaller amount of molten iron can be input relative to the amount of scrap, thereby reducing greenhouse gas emissions at the steelworks. The background technology of the present invention is disclosed in Korean Patent Publication No. 10-2013-0075806 (published July 8, 2013; Title of Invention: Device for Detecting Swelling of a Lance for Refining in a Converter). FIG. 1 is a schematic diagram illustrating a converter equipped with a blowing lance according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of a blowing lance according to one embodiment of the present invention. Figure 3 is an enlarged view of part A of Figure 2. Figure 4 is an enlarged view of part B of Figure 2. Fig. 5 is a bottom view of the blowing lance of Fig. 2. Figure 6 is a graph comparing the flow velocity of gas discharged through a cone-shaped nozzle and the flow velocity of gas discharged through a tubular nozzle when the same flow rate is introduced through a cone-shaped nozzle and a tubular nozzle. Hereinafter, a blowing lance according to the present invention will be described in detail with reference to the attached drawings. The terminology used in this specification is used to appropriately express preferred embodiments of the present invention, and may vary depending on the intent of the user or operator or the conventions of the field to which the present invention belongs. Accordingly, the definitions of these terms should be based on the content throughout this specification. FIG. 1 is a schematic diagram illustrating a furnace with a blowing lance installed according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a blowing lance according to an embodiment of the present invention, FIG. 3 is an enlarged view of part A of FIG. 2, FIG. 4 is an enlarged view of part B of FIG. 2, and FIG. 5 is a bottom view of the blowing lance of FIG. 2. Referring to FIGS. 1 and 2, the steelmaking process is a process of producing molten steel (1) by applying heat to molten iron and scrap (scrap metal) fed into a converter (10). The converter (10) includes an inlet (15) on the upper side into which molten iron and scrap are fed, and an outlet (18) on the side for discharging the produced molten steel (1). A blowing lance (100) according to one embodiment of the present invention is introduced so as to pass through the inlet (15) of a converter (10) and extend into the interior of the converter (10). When high-purity, high-pressure, high-flow oxygen gas (G1, G2, G3) is blown into the molten steel (1) from the lower part of the blowing lance (100), impurities in the molten steel (1) are rapidly oxidized to become slag (5) which can float to the upper part of the molten steel (1). During the blowing process, molten steel (1) is scattered by a high-pressure oxygen jet (G1) discharged from the main nozzle (150) and adheres to the outer surface of the blowing lance (100) or the inlet (15) of the converter (10). When it hardens due to cooling, it can become a skull (not shown). If a large amount of skull adheres, the blowing lance (100) must be removed from the converter (10) and the skull must be removed, which may result in delays in the converter process and a decrease in steelmaking productivity. Referring to FIGS. 1 to 5, a blowing lance (100) according to one embodiment of the present invention comprises a lance body (101), a main nozzle (150), a first sub-nozzle (170), and a second sub-nozzle (180). The lance body (101) has a roughly cylindrical shape and can be extended along an axis (AX) in the vertical direction. The lance body (101) is equipped with gas passages (190, 191, 193) inside. High-purity oxygen gas is supplied into the interior of the lance body (101) through the gas passage (190). The gas passage (190) may include an integrated gas passage (190), a main gas passage (191), and a sub-gas passage (193). The integrated gas passage (190) is provided at the top inside the lance body (101), and oxygen gas is introduced from the outside of the lance body (101) through the integrated gas passage (190). The main gas passage (191) is provided below the integrated gas passage (190). The oxygen gas introduced into the main gas passage (191) is discharged to the outside of the lance body (101) through the main nozzle (150) located at the bottom of the lance body (10). The oxygen gas discharged from the main nozzle (150) below m