KR-20260066339-A - plated steel sheet manufacturing apparatus

Abstract

The present invention provides a plated steel sheet manufacturing apparatus comprising: a gas knife that sprays wiping gas onto a plated steel sheet to control the plating amount of the plated steel sheet; and a cooling unit that supplies cooled wiping gas to the gas knife.

Inventors

• 김윤구
• 최형훈

Assignees

• 주식회사 포스코

Dates

Publication Date

20260512

Application Date

20241104

Claims (9)

1. A gas knife for controlling the plating amount of a plated steel plate by spraying wiping gas onto the plated steel plate; and A plated steel sheet manufacturing apparatus comprising a cooling unit that supplies cooled wiping gas to the above gas knife.
2. In paragraph 1, the cooling unit is, A supply line for supplying wiping gas to the gas knife; and A galvanized steel sheet manufacturing apparatus comprising: a heat exchanger installed in the above supply line and cooling the wiping gas supplied through the above supply line.
3. In paragraph 2, A galvanized steel sheet manufacturing apparatus in which a plurality of the above heat exchangers are installed in the above supply line and the plurality of heat exchangers can be individually temperature controlled.
4. In paragraph 1, the cooling unit is, A supply line that supplies wiping gas to the gas knife; A first heat exchanger installed on one side of the supply line and cooling the wiping gas supplied through the supply line; and A plated steel sheet manufacturing apparatus comprising: a second heat exchanger installed on the other side of the supply line and cooling the wiping gas supplied through the supply line.
5. In paragraph 4, the cooling unit is, A 1-1 thermometer for measuring the temperature of the wiping gas introduced for heat exchange with the first heat exchanger; A first-2 thermometer for measuring the temperature of the wiping gas withdrawn after completing heat exchange with the first heat exchanger; A 2-1 thermometer for measuring the temperature of the wiping gas introduced for heat exchange with the above-mentioned 2nd heat exchanger; and A plated steel sheet manufacturing apparatus further comprising a second-2 thermometer for measuring the temperature of the wiping gas withdrawn after completing heat exchange with the second heat exchanger.
6. In paragraph 5, A galvanized steel sheet manufacturing apparatus in which the first heat exchanger and the second heat exchanger are arranged adjacent to each other, and one thermometer acts as the first-2 thermometer and the second-1 thermometer.
7. In paragraph 4, the cooling unit is, A first bypass line installed in the supply line and installed to bypass the first installation area of the supply line where the first heat exchanger is installed; and A plated steel sheet manufacturing apparatus further comprising: a second bypass line installed in the supply line and installed to bypass the second installation area of the supply line where the second heat exchanger is installed.
8. In paragraph 1, The above gas knife is a plated steel sheet manufacturing device that sprays wiping gas cooled to a set temperature in the range of 5 to 10 degrees (°C) by the above cooling unit.
9. In paragraph 1, A plated steel sheet manufacturing apparatus further comprising a shielding unit installed to surround the periphery of the above gas knife.

Description

plated steel sheet manufacturing apparatus The present invention relates to a galvanized steel sheet manufacturing apparatus that reduces quality defects in galvanized steel sheets. It should be noted that the content described in this section merely provides background information regarding the present invention and does not constitute prior art. Generally, steel plates are the most well-known representative steel products produced at steel mills. These steel plates are sometimes shipped and sold without separate post-processing after manufacturing, or various post-processing steps may be taken to improve product quality. A representative example of such post-treatment processes is the plating process, which is used to prevent surface corrosion of steel plates. Referring to FIG. 1, in the plating process, a steel plate is immersed in a molten plating solution in a plating tank (P), and then the molten plating solution adhering to the plated steel plate (S) is passed through a gas knife (100) that sprays high-pressure gas to control the amount of plating attached to the surface of the plated steel plate (S). However, during solidification, the unsolidified plating layer of the plated steel sheet (S) may flow down more in the center portion than in the edge portion of the plated steel sheet (S). Consequently, as the plating layer in the center portion of the plated steel sheet (S) flows down, tension may be generated, and defects such as downwardly inclined blowing marks (M) may occur in the edge portion of the plated steel sheet (S). Figure 1 is a drawing illustrating the state in which quality defects, such as blowing marks, occur on a plated steel sheet in a conventional plated steel sheet manufacturing apparatus. FIG. 2 is a cross-sectional view of a plated steel sheet manufacturing apparatus according to one embodiment of the present invention. FIG. 3 is a cross-sectional view of a plated steel sheet manufacturing apparatus according to another embodiment of the present invention. FIG. 4 is a drawing illustrating an example of a cooling unit included in the plated steel sheet manufacturing apparatus of FIG. 2 and FIG. 3. FIG. 5 is a drawing illustrating another example of a cooling unit included in the plated steel sheet manufacturing apparatus of FIG. 2 and FIG. 3. Preferred embodiments of the present invention will be described below with reference to the attached drawings. However, embodiments of the present invention may be modified in various different forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. In the drawings, the shapes and sizes of elements may be exaggerated for clearer explanation. In describing the embodiments of the present invention, if it is determined that a detailed description of known technology related to the present invention may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. The terms used in the detailed description are merely for describing the embodiments of the present invention and should not be limited in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form. In this description, expressions such as “include” or “equipped” are intended to refer to certain characteristics, numbers, steps, actions, elements, parts or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts or combinations thereof other than those described. In this specification, terms such as 'top', 'upper', 'upper surface', 'lower', 'lower surface', 'lower surface', and 'side surface' are based on the drawings and may actually vary depending on the direction in which the elements or components are arranged. Additionally, throughout the specification, when it is said that a part is 'connected' to another part, this includes not only cases where they are 'directly connected,' but also cases where they are 'indirectly connected' with other elements in between. The present invention will be described in detail below through each embodiment or example of the invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may also be combined with other embodiments or examples. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interp