A leakage-proof RH furnace bottom groove structure

Abstract

The utility model discloses a leakage-proof RH furnace bottom groove structure, comprising a circulation pipe brick, a bottom groove brick, a lower groove brick, and a castable densely filled in the annular seam area between the circulation pipe brick and the bottom groove brick, and between the circulation pipe brick and the lower groove brick. The RH furnace bottom groove structure also includes one or more bottom groove retaining bricks extending into the annular seam area, and the castable in the annular seam area is divided into several sections by the bottom groove retaining bricks. The utility model can effectively improve the safety factor of the junction area between the circulation pipe and the bottom groove, and the circulation pipe and the lower groove, greatly reduce the leakage accidents at the junction of the RH furnace groove bottom and the groove bottom and the groove wall, and is particularly suitable for the smelting of high-grade electrical steel and ultra-low carbon automotive plates and other steel types with harsh refining conditions.

Description

Technical Field

[0001] The utility model relates to the field of RH furnaces in iron and steel metallurgy, and in particular to a leakage-proof bottom groove structure of an RH furnace. Background Art

[0002] RH furnace is an indispensable off-furnace refining metallurgical vessel for producing high-grade steels such as automotive plates, electrical steel, bearing steel, pipeline steel, etc. Such steels generally have the characteristics of high refining temperature, long refining time, large amount of alloy addition, and even the addition of fluorite-containing desulfurizers and other harsh processes, which cause serious melting loss of RH furnace insert tubes and bottom groove refractory materials.

[0003] The patent specification with the announcement number CN210104001U discloses a new structure of the circulation pipe of the RH furnace, including the upper ring brick of the circulation pipe and the lower ring brick of the circulation pipe surrounding the inner wall of the furnace body, the upper ring brick of the circulation pipe is laid and arranged at the upper position of the lower ring brick of the circulation pipe, and a new ring brick is laid on the top of the upper ring brick of the circulation pipe, and the upper surface of the new ring brick is on the same horizontal plane as the upper surface of the furnace bottom brick. By adding the new ring brick on the upper surface of the traditional upper ring brick of the circulation pipe, the ring brick is level with the furnace bottom of the vacuum chamber, eliminating the unfavorable conditions such as the accumulation of molten steel due to the sinking and deformation of the furnace bottom, and enhancing the overall performance of the furnace bottom refractory material, thereby improving the use performance of the circulation pipe brick, extending the service life of the RH furnace circulation pipe, and increasing the replacement cycle of the circulation pipe brick. Combined with the drawings of the patent technology, it can be seen that in the patent technology, there is still a ring gap between the circulation pipe and the bottom groove using castable or ramming material bulk.

[0004] like Figure 1 As shown, the annular seam area between the existing circulation pipe and the bottom groove is generally constructed with amorphous refractory materials such as ramming materials or castable materials due to its irregular geometric dimensions. The amorphous refractory materials have poor scouring and melting resistance performances as the bottom groove bricks and circulation pipe bricks around them, and will be damaged first during use to form an annular pit. If the molten steel continues to erode vertically downward in this pit channel, it will weaken the fixing effect of the amorphous bulk material on the circulation pipe bricks, causing the circulation pipe bricks to break or float up; if the molten steel erodes horizontally toward the permanent layer at the junction of the circulation pipe and the lower groove in this pit channel, a serious melt hole (commonly known as a mouse hole) that reaches the permanent layer directly will be formed at the junction. The breakage or floating of the circulation pipe bricks cannot be maintained by spraying materials, and the abnormal melt hole at the junction of the circulation pipe bricks and the lower groove bricks is even more difficult to find in a hot state, which can easily cause abnormal leakage of steel at the bottom of the bottom groove or at the junction of the bottom groove and the lower groove. Utility Model Content

[0005] In view of the above-mentioned technical problems and the deficiencies in the art, the utility model provides a leakage-proof RH furnace bottom trough structure, which can effectively improve the safety factor of the junction area between the circulation pipe and the bottom trough, and the circulation pipe and the lower trough, and greatly reduce the leakage accidents at the junction of the RH furnace trough bottom and the trough bottom and the trough wall. It is particularly suitable for the smelting of high-grade electrical steel, ultra-low carbon automotive plates and other steel types with harsh refining conditions.

[0006] The specific technical solutions are as follows:

[0007] A leakage-proof RH furnace bottom trough structure comprises circulating pipe bricks, bottom trough bricks, lower trough bricks and castables densely filling the annular seam areas between the circulating pipe bricks and the bottom trough bricks and between the circulating pipe bricks and the lower trough bricks. The RH furnace bottom trough structure also comprises one or more (e.g., 2, 4, 6, 7, etc.) bottom trough retaining bricks extending into the annular seam areas. The castables in the annular seam areas are divided into several sections by the bottom trough retaining bricks.

[0008] In some embodiments, in the bottom groove structure of the RH furnace, the width of the annular seam area between the circulating pipe bricks and the bottom groove bricks is 50 to 60 mm.

[0009] In some embodiments, in the RH furnace bottom trough structure, the bottom trough retaining brick is a protruding bottom trough brick, and the distance between the bottom trough retaining brick and the nearest circulation pipe brick is less than 10 mm.

[0010] In some embodiments, in the RH furnace bottom trough structure, the bottom trough retaining bricks are cross-laid with the adjacent bottom trough bricks to form an integrated structure to prevent the bottom trough retaining bricks from being washed away due to melting loss of the castable during use.

[0011] In some embodiments, in the bottom trough structure of the RH furnace, a bottom trough retaining brick is provided at the junction of the circulating pipe brick and the lower trough brick.

[0012] In some embodiments, the RH furnace bottom trough structure, the castable is a corundum spinel castable.

[0013] In some embodiments, the bottom trough structure of the RH furnace, the circulating pipe bricks, the bottom trough bricks, the lower trough bricks and the bottom trough retaining bricks are all magnesium spinel unfired bricks.

[0014] In some embodiments, the bottom groove structure of the RH furnace has a plurality of bottom groove blocking bricks, which are symmetrically arranged along the annular seam area. The symmetry may be axial symmetry or the like.

[0015] In the anti-leakage RH furnace bottom trough structure of the utility model, the bottom trough retaining bricks are arranged to divide the castable into several independent sections, and the following technical solutions can be preferably selected in any one or more combinations:

[0016] The castable is preferably a corundum spinel castable;

[0017] The refractory material is preferably low-carbon, green and environmentally friendly magnesium spinel unburned brick;

[0018] It is preferred to control the annular gap of the circulation pipe brick and the bottom groove brick to 50-60mm, and minimize its usage under the premise of satisfying the construction of the castable;

[0019] Preferably, a plurality of protruding bottom groove bricks are symmetrically arranged along the circumferential direction of the annular seam. These protruding bottom groove bricks preferably protrude into the annular seam area to a distance of less than 10 mm from the nearest circulation pipe brick (the protruding bottom groove brick can be called a bottom groove retaining brick), and it is particularly preferred to focus on arranging the bottom groove retaining brick at the junction of the circulation pipe brick and the lower groove brick;

[0020] Preferably, the annular gap area between the circulating pipe and the bottom groove brick is compacted by vibration casting with corundum castable material.

[0021] During use of the leakage-proof RH furnace bottom trough structure of the utility model, the melting loss rate of the corundum spinel castable is greater than that of the magnesium spinel brick, thereby forming a concave molten steel channel in the annular seam area of ​​the circulation tube and the bottom trough. However, due to the presence of the bottom trough retaining bricks, the channel can be effectively blocked from continuing to expand toward the permanent layer of the bottom trough, and the molten steel can be blocked from penetrating through the channel to the permanent layer of the lower trough wall, thereby alleviating the fracture and floating of the circulation tube bricks, greatly improving the safety factor of the junction area between the circulation tube and the lower trough, and greatly reducing the leakage accidents at the RH furnace trough bottom and at the junction of the trough bottom and the trough wall. The utility model is particularly suitable for the smelting of high-grade electrical steel and ultra-low carbon automotive plates.

[0022] Compared with the prior art, the utility model has the following beneficial effects:

[0023] Unburned magnesium spinel retaining bricks are used to divide the annular seam into several sections, and then the corundum spinel castable in the annular seam is divided into several sections. During use, although the castable will melt and lose before the circulation pipe bricks and bottom groove bricks to form pits and accumulate molten steel, it will stop expanding when it encounters the retaining bricks in the annular seam. In the vertical direction, smaller pits will not cause the circulation pipe bricks to lose support and break and float up; in the horizontal direction, the molten steel will also lose the channel to penetrate into the permanent layer at the junction of the circulation pipe bricks and the groove wall bricks, and will not produce abnormal melting loss like "rat holes" there.

[0024] Through the structure and masonry mode of the utility model, the frequent broken bricks and floating bricks accidents of the circulation pipe due to the inability of the amorphous materials in the annular seam between the circulation pipe and the bottom trough bricks to withstand melting loss can be effectively reduced from the current 10-15% to below 2%, and the accidents of leakage caused by abnormal melting loss in the shape of a "rat hole" at the junction of the circulation pipe and the lower trough brick can be effectively reduced from the current 5-10% to below 1%, thereby greatly improving the safety factor of the bottom trough of the RH furnace in the hot state and stabilizing its service life. It is particularly suitable for smelting high-grade steels such as automobile plates, electrical steel, bearing steel, pipeline steel, etc., which have long refining time, high refining temperature and require the addition of fluorite-containing desulfurizers. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a top view schematic diagram of the existing RH furnace bottom trough masonry structure;

[0026] Figure 2 It is a top view schematic diagram of a bottom groove structure of an RH furnace for preventing leakage according to the utility model;

[0027] In the figure: ascending circulation pipe 1, descending circulation pipe 2, bottom trough brick 3, lower trough brick 4, castable 5, bottom trough retaining bricks 11, 12, 21, 22, 31, 32, 6. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0029] See also Figure 2 A leakage-proof bottom groove structure of an RH furnace includes a circulation pipe brick located outside an ascending circulation pipe 1 and a descending circulation pipe 2, a bottom groove brick 3, a lower groove brick 4, and a castable 5 densely filled in the annular gap area between the circulation pipe brick and the bottom groove brick 3 and between the circulation pipe brick and the lower groove brick 4. The castable 5 is a corundum spinel castable. The width of the annular gap area between the circulation pipe brick and the bottom groove brick 3 is 50 to 60 mm.

[0030] The bottom groove structure of the RH furnace also includes a plurality of bottom groove retaining bricks 11, 12, 21, 22, 31, 32, 6 extending into the annular seam area, and these bottom groove retaining bricks are arranged symmetrically along the circumferential axis of the annular seam area, wherein the bottom groove retaining bricks 11 and 12 are located at the junction of the circulating pipe brick and the lower groove brick 4. The castable 5 in the annular seam area is divided into 7 sections by the bottom groove retaining bricks. The bottom groove retaining brick is a protruding bottom groove brick, and the distance between the bottom groove retaining brick and the nearest circulating pipe brick is less than 10 mm. The bottom groove retaining brick and its adjacent bottom groove bricks are cross-laid into an integrated structure.

[0031] The circulating pipe bricks, the bottom trough bricks 3, the lower trough bricks 4 and the bottom trough retaining bricks are all magnesium spinel unfired bricks.

[0032] The above-mentioned RH furnace bottom trough structure and masonry scheme are applied to a 300-ton RH furnace in a large domestic steel plant. The refining ratio of high-grade oriented silicon steel and non-oriented silicon steel is >50%, the accidents of broken and floating bricks in the upper section of the circulation tube have been reduced from 10% to less than 2%, and the accidents of "rat hole"-like abnormal melting and leakage at the junction of the circulation tube and the lower trough have been reduced from 8% to less than 1%, and the average life of the bottom trough overhaul has been increased by more than 10%.

[0033] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A leakage-proof bottom trough structure of an RH furnace, comprising a circulating pipe brick, a bottom trough brick, a lower trough brick, and a castable densely filled in the annular seam area between the circulating pipe brick and the bottom trough brick, and between the circulating pipe brick and the lower trough brick, characterized in that: The RH furnace bottom trough structure further comprises one or more bottom trough retaining bricks extending into the annular gap area, and the castable in the annular gap area is divided into several sections by the bottom trough retaining bricks.

2. The RH furnace bottom groove structure according to claim 1, characterized in that: The width of the annular seam area between the circulating pipe bricks and the bottom groove bricks is 50 to 60 mm.

3. The RH furnace bottom groove structure according to claim 1 or 2, characterized in that: The bottom groove retaining brick is a protruding bottom groove brick, and the distance between the bottom groove retaining brick and the nearest circulation pipe brick is less than 10 mm.

4. The RH furnace bottom groove structure according to claim 3, characterized in that: The bottom groove retaining bricks and the adjacent bottom groove bricks are cross-laid to form an integrated structure.

5. The RH furnace bottom groove structure according to claim 3, characterized in that: A bottom groove retaining brick is provided at the junction of the circulating pipe brick and the lower groove brick.

6. The RH furnace bottom groove structure according to claim 1, characterized in that: The castable is a corundum spinel castable.

7. The RH furnace bottom groove structure according to claim 1, characterized in that: Circulation pipe bricks, bottom trough bricks, lower trough bricks and bottom trough retaining bricks are all magnesium spinel unfired bricks.

8. The RH furnace bottom groove structure according to claim 1, characterized in that: There are multiple bottom groove blocking bricks, which are symmetrically arranged along the circumferential direction of the annular seam area.

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