On-line fettling die for direct-current electric arc furnace lining

Abstract

The utility model relates to an online fettling die for a direct-current electric arc furnace lining, and belongs to the technical field of electric arc furnace smelting equipment. Comprising a hollow mold body, the top of the mold body is provided with a plurality of lifting rings which are evenly distributed in the annular direction, and the lifting rings are connected with steel wire ropes and connected with crown block lifting hooks through the steel wire ropes; and the crown block lifts the mold body into the inner cavity of the furnace body, so that the bottom of the mold body covers the electrode center circle of the bottom electrode. The die body is a big-end-up circular ring structural member. The diameter of a lower opening of the mold body exceeds the diameter of the electrode center circle of the bottom electrode by 500-1000mm; the diameter of an upper opening of the die body is 300-1000 mm larger than that of a lower opening of the die body. The device is simple in structure and convenient to operate, bulk refractory materials are prevented from covering the bottom electrode, and smooth production after fettling is guaranteed.

Description

Technical Field

[0001] This utility model relates to an online furnace lining repair mold for a DC electric arc furnace, belonging to the technical field of electric arc furnace smelting equipment. Background Technology

[0002] Electric arc furnace (EAF) smelting is a crucial method in steelmaking, and with the gradual implementation of national dual-carbon requirements, its proportion will significantly increase. EAF smelting utilizes a high scrap ratio, with scrap pieces of varying sizes, resulting in substantial mechanical impact on the furnace lining during charging. As smelting progresses, the EAF lining is primarily subjected to mechanical impact during charging, physical erosion from the circulating flow of steel, chemical corrosion from high-temperature slag, and rapid heating and cooling during tapping / charging, causing frequent expansion and contraction of the refractory material, leading to cracks and even spalling. Therefore, EAF lining erosion is inevitable. Consequently, repairs are unavoidable during EAF operation, making online furnace repair a vital aspect of the EAF smelting process.

[0003] When repairing the lining of a DC electric arc furnace, manual feeding can easily cause loose refractory material to cover the bottom electrode, resulting in poor conductivity of the bottom electrode and affecting the smooth operation of production after the furnace is repaired. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide an online furnace lining repair mold for DC electric arc furnaces, which is simple in structure and easy to operate, avoids the refractory material covering the bottom electrode, and ensures smooth production after furnace repair.

[0005] The technical solution adopted by this utility model to solve the above problems is as follows: an online furnace lining repair mold for a DC electric arc furnace, comprising a hollow mold body, a plurality of circumferentially distributed lifting rings on the top of the mold body, the lifting rings being connected to steel wire ropes and connected to a crane hook through the steel wire ropes; the crane lifts the mold body into the inner cavity of the furnace body, so that the bottom of the mold body is covered with the bottom electrode center circle.

[0006] The mold body is a circular structure that is larger at the top and smaller at the bottom.

[0007] The lower diameter of the mold body exceeds the diameter of the bottom electrode center circle by 500-1000 mm; the upper diameter of the mold body is 300-1000 mm larger than the lower diameter.

[0008] The height of the mold body is 100~500mm, and the thickness of the mold body is less than 10mm.

[0009] Compared with the prior art, the advantages of this utility model are: an online furnace lining repair mold for a DC electric arc furnace has a simple structure and convenient operation, avoids the loose refractory material from covering the bottom electrode, and ensures smooth production after furnace repair. Attached Figure Description

[0010] Figure 1 This is a three-dimensional schematic diagram of an online furnace lining repair mold for a DC electric arc furnace according to an embodiment of the present invention;

[0011] Figure 2 This is a schematic diagram of the operation of an online furnace lining repair mold for a DC electric arc furnace according to an embodiment of the present invention;

[0012] In the diagram, 1 is the mold body, 2 is the lifting ring, 3 is the furnace wall, 4 is the furnace body, 5 is the furnace filler charge, and 6 is the bottom electrode. Detailed Implementation

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0014] like Figure 1 , 2 As shown, this embodiment of an online furnace lining repair mold for a DC electric arc furnace includes a hollow mold body 1. The mold body 1 is a circular ring structure with a larger upper part and a smaller lower part, and its cross-section is an inverted cone shape. Three circumferentially distributed lifting rings 2 are provided on the top surface of the mold body 1. Each lifting ring 2 is connected to a steel wire rope, which is then connected to a crane hook. The crane is started to lift the mold body 1 into the inner cavity of the furnace body 4, so that the bottom of the mold body 1 covers the center circle of the bottom electrode 6, forming a barrier. This ensures that the repair material 5 only falls in the repair area between the furnace wall 3 and the outer wall of the mold body 1, preventing loose refractory material from covering the bottom electrode 6. The crane operator can adjust the height and horizontal position of the mold body in real time to ensure that the lower opening of the mold body always covers the center circle of the bottom electrode.

[0015] The lower diameter B of the mold body exceeds the diameter of the bottom electrode's center circle by 500-1000 mm. The upper diameter A of the mold body is 300-1000 mm larger than the lower diameter B, and its inverted conical shape serves as a guide, allowing the repair material to be spread to the furnace wall area requiring repair, avoiding blind spots in the repair process. The height H of the mold body is 100-500 mm to prevent the mold body from being too high and obstructing the crane operation, or too low and causing the repair material to splash onto the bottom electrode. The thickness of the mold body is less than 10 mm to reduce its weight and the load on the crane.

[0016] When furnace repair is required, depending on the furnace condition, all molten steel, including slag, should be poured out, and the electric arc furnace should be leveled. The mold body is then lowered into the furnace cavity using an overhead crane, ensuring that the bottom opening of the mold body completely covers the center circle of the bottom electrode. The overhead crane suspends the mold body throughout the repair process. Another overhead crane carries the repair material along the outside of the mold body; as the bottom of the bag melts, the repair material is poured between the outer wall of the mold body and the furnace wall. The repair area is checked for any omissions via video monitoring from the furnace door or roof, ensuring that all areas requiring repair are repaired. Finally, light scrap steel is added to the basket, and the furnace is shut down for at least two hours before being re-energized with oxygen for remelting.

[0017] This application features a simple structure and convenient operation. The mold body forms a barrier against the bottom electrode, ensuring that the repair material only falls in the repair area between the furnace wall and the outer wall of the mold body, thus preventing loose refractory material from covering the bottom electrode. The inverted conical structure of the mold body guides the repair material, avoiding repair blind spots.

[0018] In addition to the above embodiments, this utility model also includes other implementation methods. All technical solutions formed by equivalent transformation or equivalent substitution should fall within the protection scope of the claims of this utility model.

Claims

1. A mold for online furnace lining repair of a DC electric arc furnace, characterized in that: The mold includes a hollow mold body, with multiple circumferentially distributed lifting rings on the top of the mold body. Each lifting ring is connected to a steel wire rope, which is then connected to a crane hook. The crane lifts the mold body into the inner cavity of the furnace, so that the bottom of the mold body is covered with the center circle of the bottom electrode.

2. The online furnace lining repair mold for a DC electric arc furnace according to claim 1, characterized in that: The mold body is a circular structure that is larger at the top and smaller at the bottom.

3. The online furnace lining repair mold for a DC electric arc furnace according to claim 1, characterized in that: The lower diameter of the mold body exceeds the diameter of the bottom electrode center circle by 500-1000 mm; the upper diameter of the mold body is 300-1000 mm larger than the lower diameter.

4. The online furnace lining repair mold for a DC electric arc furnace according to claim 1, characterized in that: The height of the mold body is 100~500mm, and the thickness of the mold body is less than 10mm.

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