Hot-state repairing mold for bottom groove of vacuum chamber of RH refining furnace and repairing method of hot-state repairing mold

By designing a thermal repair mold and repair method for the bottom groove of the vacuum chamber of the RH refining furnace, the problem of lowering the line caused by thermal peeling of the bottom groove is solved, and the effect of extending service life, shortening turnover cycle and reducing costs is achieved.

CN119932268APending Publication Date: 2025-05-06ANSHAN HEFENG REFRACTORY MATERIAL CO LTD
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Patent Information

Application Number
CN202510318344.5
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-03-18
Publication Date
2025-05-06

AI Technical Summary

Technical Problem

The bottom of the groove bottom of the vacuum chamber of the RH refining furnace and the joint of the circulation pipe are prone to thermal peeling due to water erosion of steel, steel slag erosion and thermal shock, resulting in sudden brick breakage or serious erosion, and the line is removed at a young age, resulting in waste of material.

Method used

A thermal repair mold at the bottom groove of the RH refining furnace vacuum chamber is designed, including a structure composed of a chassis, straight sections and conical sections. The mold is inserted into the bottom groove during the RH vacuum operation interval, and combined with the use of spraying and high-temperature self-flow repair, thermal repair is achieved.

Benefits of technology

This method can repair the bottom groove without down-line operation, extend the service life of the circulation pipe and impregnated pipe, shorten the turnover cycle of the vacuum chamber, reduce the use of refractory materials, and reduce production costs.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention discloses a hot-state repairing mold for a bottom groove of a vacuum chamber of an RH (Ruhrstahl Heraeus) refining furnace, and relates to the technical field of vacuum smelting furnaces, the mold comprises a base plate, a straight section and a conical section in sequence from bottom to top; wherein the diameter of the straight section is 50-100mm smaller than the inner diameters of a dip pipe and a circulating pipe in the original bottom tank; the chassis is connected with the bottom of the straight section, and the width of the chassis is larger than the diameter of the straight section; the conical section is connected with the top of the straight section and is in a triangular cone shape, and the diameter of the bottom face of the conical section is the same as that of the straight section. According to the repairing mold, the purpose of repairing the bottom groove can be achieved only in the vacuum operation intermittent period of the RH refining furnace, operation modes such as brick digging, replacement or filling through RH bottom groove offline operation are not needed, the service life of a circulating pipe and a dipping pipe of the RH bottom groove can be prolonged, the turnover period of a vacuum chamber is shortened, the use amount of refractory materials is reduced, and the production cost is reduced. The production cost is reduced.
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Description

Technical Field

[0001] The invention relates to the technical field of vacuum refining furnaces, and in particular to a hot repairing mold for a bottom groove of a vacuum chamber of an RH refining furnace and a repairing method thereof. Background Art

[0002] With the development of science and technology and the rapid growth of economy, people's demand for high-quality clean steel is also increasing day by day. RH refining furnace is one of the important high-temperature devices for smelting high-quality clean steel. It has the functions of dehydrogenation, decarbonization, deoxidation, desulfurization, precise control of molten steel composition and temperature, and inclusion control and removal. With the development of RH vacuum smelting technology, the varieties suitable for smelting have increased significantly, becoming an indispensable refining equipment for smelting high-level pipelines, ultra-low carbon steel, silicon steel and other high-value-added steels, which also puts forward higher and higher requirements on the performance of RH refractory materials.

[0003] At present, most iron and steel metallurgical enterprises often use magnesia-chromium refractory materials as the lining of the working layer of RH refining furnace. However, during use, since the circulation pipe, immersion pipe and bottom tank of the RH furnace are in direct contact with molten steel, they are eroded by molten steel, eroded by slag and melted, and thermally flaked due to thermal shock. As a result, the joint between the bottom of the RH bottom tank and the circulation pipe is often offline at a young age due to sudden brick breakage or severe erosion during use, while the working linings of other parts are intact, which not only disrupts the production plan rhythm of the steel plant but also causes a waste of refractory costs.

[0004] Therefore, providing a hot repair method for the RH vacuum smelting bottom tank to compensate for the sudden breakage of bricks or severe erosion during use and premature offline, extending the service life of the RH bottom tank, saving refractory materials and reducing costs are technical problems that need to be urgently solved in this field. Summary of the invention

[0005] The invention aims at the problem that the bottom groove of the vacuum chamber of the RH refining furnace and the joint part of the circulating flow pipe suddenly break or are seriously corroded during use, and proposes a hot repairing mold and a repairing method for the bottom groove of the vacuum chamber of the RH refining furnace.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A hot repair mold for the bottom groove of a vacuum chamber of an RH refining furnace, the mold comprising, from bottom to top, a bottom plate, a straight section and a conical section;

[0008] The diameter of the straight section is 50-100 mm smaller than the inner diameter of the immersion pipe and the circulation pipe in the original bottom tank;

[0009] The bottom plate is connected to the bottom of the straight section, and the width of the bottom plate is greater than the diameter of the bottom surface of the straight section;

[0010] The cone section is connected to the top of the straight section and is in a triangular pyramid shape, and the bottom diameter of the cone section is the same as the top diameter of the straight section.

[0011] Preferably, the chassis is a cylinder, and the diameter of the chassis is 200-400 mm larger than the diameter of the bottom surface of the straight section.

[0012] Preferably, the height of the straight section is 100-350 mm higher than the total height of the immersion pipe and the circulation pipe in the original bottom tank.

[0013] Preferably, the height of the cone section is 200-400 mm.

[0014] Preferably, the straight section is cylindrical and / or truncated cone-shaped.

[0015] Preferably, the chassis and the straight section are made of 5-20 mm thick steel plates, and the chassis is made of 5-20 mm thick steel plates.

[0016] A method for hot repairing a bottom groove of a vacuum chamber of an RH refining furnace comprises the following steps:

[0017] (1) After the RH vacuum operation is completed, the temperature is raised to melt all the residual steel in the bottom tank, and the mold is inserted upward from the bottom of the immersion pipe in the bottom tank into the bottom tank, with the bottom plate close to the bottom of the immersion pipe;

[0018] (2) After the step (1) is completed, the bottom groove repair material is added through the alloy feeding port. After the bottom groove repair material is completely sintered or hardened, the mold is taken out, and the entire repair operation is completed.

[0019] Preferably, in step (1), the gap between the mold and the bottom of the immersion tube is filled with gunning material.

[0020] Preferably, the gunning material is ordinary magnesia refractory gunning material.

[0021] Preferably, the bottom groove repair material in step (2) is any one of magnesium, magnesium-chromium and aluminum refractory materials, which can be ordinary castables or high-temperature self-flowing repair materials based on an asphalt bonding system.

[0022] Preferably, the bottom groove repair material in step (2) comprises the following raw materials in mass percentage: 20% 3-5mm fused magnesia, 20% 1-3mm fused magnesia, 25% 0.1-1mm fused magnesia, 19.5% 180-240 mesh fused magnesia, 13% asphalt and 2.5% fuel oil;

[0023] Preferably, the bottom groove repair material in step (2) comprises the following raw materials in percentage by mass: 20% 3-6mm plate corundum, 25% 1-3mm plate corundum, 25% 0.1-1mm plate corundum, 15.8% 280-325 mesh plate corundum, 8% alumina powder, 6% cement, 0.1% explosion-proof fiber and 0.1% water reducer.

[0024] Preferably, the water reducer is at least one of sodium tripolyphosphate, sodium hexametaphosphate or a polycarboxylic acid-based high-efficiency water reducer.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The repair mold provided by the present invention can achieve the purpose of repairing the bottom tank only during the interval of vacuum operation of the RH refining furnace, without the need to perform operations such as digging bricks, replacing or filling the RH bottom tank offline. This can not only increase the service life of the RH bottom tank circulation pipe and immersion pipe, but also shorten the turnover cycle of the vacuum chamber, reduce the use of refractory materials, and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings in this description are only embodiments of the present invention.

[0028] Figure 1 This is a structural diagram of a mold according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the damage of the bottom groove of RH in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of assembling the RH bottom slot mold according to an embodiment of the present invention;

[0031] Figure 4 This is a mold structure diagram of Example 2 of the present invention. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but are not to be construed as limiting the present invention.

[0033] Example 1

[0034] like Figure 2 Taking the refining operation area of ​​a large steel plant in Northeast China as an example, the inner diameter D1 of the original circulation pipe and immersion pipe in the bottom tank of its RH refining furnace is 750mm, and the height H1 of the original circulation pipe and immersion pipe is 1650mm;

[0035] like Figure 1The present invention provides a hot state repair mold for the bottom groove of the vacuum chamber of an RH refining furnace: the mold comprises a bottom plate 1, a straight section 2 and a conical section 3 from bottom to top, wherein:

[0036] Cone section 3 is triangular cone-shaped, rolled from 5-20mm thick steel plate, with a height H3 of 150mm;

[0037] The straight section 2 is composed of a cylindrical shape and a truncated cone shape, both of which are rolled from a 5-20 mm thick steel plate. The height dimension H2 of the straight section 2 is 1800 mm. The bottom diameter of the truncated cone is the same as the diameter of the cylinder, and the bottom surface of the truncated cone and the upper surface of the cylinder are welded. The diameter D2 of the cylinder is 680 mm, the height is 1650 mm, and the top surface diameter of the truncated cone is 630 mm. The top surface of the truncated cone is welded to the bottom surface of the conical section 3.

[0038] Chassis 1 is disc-shaped and is cut from 20-25mm thick steel plate. Figure 1 As shown, it is welded in the center at the bottom of the straight section 2;

[0039] A method for hot repairing a bottom groove of a vacuum chamber of an RH refining furnace comprises the following steps:

[0040] (1) After the vacuum operation of the RH refining furnace is completed, the temperature is immediately raised to melt all the residual steel in the bottom tank to ensure that there is no residual steel, slag, etc. left in the repaired area; the above mold is fixed on the lifting platform, and the center distance between the two molds is consistent with the center distance between the upper and lower immersion pipes. The mold is inserted from the bottom of the immersion pipe upward into the bottom tank through the lifting platform, and the bottom plate of the mold is close to the bottom of the immersion pipe (such as Figure 3 ), use ordinary magnesium gunning material to fill the gap between the mold and the bottom of the immersion tube;

[0041] (2) After completing step (1), the bottom groove repair material is added in the form of a small bag through the alloy feeding port. The amount added depends on the amount of damage. After the bottom groove repair material is completely sintered, the sintering time is 15 minutes. After waiting for 20 minutes, the mold is pulled out through the lifting platform, and the entire repair operation is completed. The specific components and proportions of the bottom groove repair material are shown in Table 1: Through the melting of asphalt, the high-temperature self-flowing repair material is driven to flow into the required repair position to achieve the repair purpose.

[0042] Table 1 Ratio of raw materials for bottom groove repairing materials

[0043] raw material Specification Proportion,% 96 Ordinary Fused Magnesia 3-5mm 20 96 Ordinary Fused Magnesia 1-3mm 20 96 Ordinary Fused Magnesia 0.1-1mm 25 96 Ordinary Fused Magnesia 180-240 mesh 19.5 asphalt 0-1mm 13 Fuel oil 2.5

[0044] Example 2

[0045] like Figure 2 Taking the refining operation area of ​​a large steel plant in Northeast China as an example, the inner diameter D1 of the original circulation pipe and immersion pipe in the bottom tank of its RH refining furnace is 750mm, and the height H1 of the original circulation pipe and immersion pipe is 1650mm;

[0046] like Figure 4 The present invention provides a hot state repair mold for the bottom groove of the vacuum chamber of an RH refining furnace: the mold comprises a bottom plate 1, a straight section 2 and a conical section 3 from bottom to top, wherein:

[0047] Cone section 3 is triangular cone-shaped, rolled from 5-20mm thick steel plate, with a height H3 of 150mm;

[0048] The straight section 2 is in the shape of a truncated cone and is rolled from a 5-20 mm thick steel plate. The height dimension H2 of the straight section 2 is 1800 mm. The bottom diameter D2 of the truncated cone is 680 mm, the height is 1650 mm, and the top diameter of the truncated cone is 630 mm. The top surface of the truncated cone is welded to the bottom surface of the conical section 3.

[0049] Chassis 1 is disc-shaped and is cut from 20-25mm thick steel plate. Figure 4 As shown, it is welded in the center at the bottom of the straight section 2;

[0050] A method for hot repairing a bottom groove of a vacuum chamber of an RH refining furnace comprises the following steps:

[0051] (1) After the vacuum operation of the RH refining furnace is completed, the temperature is immediately raised to melt all the residual steel in the bottom tank to ensure that there is no residual steel, slag, etc. left in the repaired area; the above mold is fixed on the lifting platform, and the center distance between the two molds is consistent with the center distance between the upper and lower immersion pipes. The mold is inserted from the bottom of the immersion pipe upward into the bottom tank through the lifting platform, and the bottom plate of the mold is close to the bottom of the immersion pipe (such as Figure 3 ), use ordinary magnesium gunning material to fill the gap between the mold and the bottom of the immersion tube;

[0052] (2) After completing step (1), the bottom groove repair material is added in the form of a small bag through the alloy feeding port. The amount added depends on the amount of damage. After the bottom groove repair material is completely hardened, the hardening time is 10 minutes. After waiting for 20 minutes, the mold is pulled out through the lifting platform. The entire repair operation is completed. The specific components and proportions of the bottom groove repair material are shown in Table 2: water needs to be added for stirring. The amount of water added is 5.5-8.5%. It is put into a small bag and added into the bottom groove through the alloy feeding port. The material flows into the required repair area due to its own fluidity.

[0053] Table 2 Ratio of raw materials for bottom groove repair material

[0054] raw material Specification Proportion,% Tabular corundum 3-6mm 20 Tabular corundum 1-3mm 25 Tabular corundum 0.1-1mm 25 Tabular corundum 280-325 mesh 15.8 Alumina powder 5μ 8 CA-70 cement 6 Explosion-proof fiber 0.1 Sodium Hexametaphosphate 0.1

[0055] Implementation effect:

[0056] 1) Save time and shorten the vacuum chamber turnover cycle. The bottom tank of the RH refining furnace can be repaired during the interval of vacuum operation of the RH refining furnace. The whole construction process can complete the repair work in 1 hour. The original construction repair method requires at least 3 days before the production operation can be put into operation;

[0057] 2) The service life of the bottom tank of the RH refining furnace can be improved. The original service life of a pair of circulation pipes and immersion pipes is 65-70 times; by adopting this repair method, the service life of a pair of circulation pipes and immersion pipes is 95-100 times;

[0058] 3) There is no need to carry out operations such as digging bricks, replacing or filling the bottom tank of the RH refining furnace offline, which reduces labor intensity and costs. On average, each set of RH bottom tank can reduce investment by more than 300,000 yuan.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hot state repair mold for the bottom groove of the vacuum chamber of an RH refining furnace, characterized in that: The mold comprises, from bottom to top, a chassis, a straight section and a tapered section; The diameter of the straight section is 50-100 mm smaller than the inner diameter of the immersion pipe and the circulation pipe in the original bottom tank; The bottom plate is connected to the bottom of the straight section, and the width of the bottom plate is greater than the diameter of the bottom surface of the straight section; The cone section is connected to the top of the straight section and is in a triangular pyramid shape, and the bottom diameter of the cone section is the same as the top diameter of the straight section.

2. The hot state repair mold for the bottom groove of the vacuum chamber of the RH refining furnace according to claim 1, characterized in that: The chassis is a cylinder, and the diameter of the chassis is 200-400 mm larger than the diameter of the bottom surface of the straight section.

3. The hot state repairing mold for the bottom groove of the vacuum chamber of the RH refining furnace according to claim 1, characterized in that: The height of the cone section is 200-400 mm.

4. The hot state repairing mold for the bottom groove of the vacuum chamber of the RH refining furnace according to claim 1, characterized in that: The straight section is cylindrical and / or truncated cone-shaped.

5. The hot state repairing mold for the bottom groove of the vacuum chamber of the RH refining furnace according to claim 1, characterized in that: The height of the straight section is 100-350 mm higher than the total height of the immersion pipe and the circulating pipe in the original bottom tank.

6. The hot state repairing mold for the bottom groove of the vacuum chamber of the RH refining furnace according to claim 1, characterized in that: The chassis and the straight section are made of 5-20 mm thick steel plates, and the chassis is made of 5-20 mm thick steel plates.

7. A hot repair method for the bottom groove of the vacuum chamber of an RH refining furnace, characterized in that: The following steps are involved: (1) After the RH vacuum operation is completed, the temperature is raised to melt all the residual steel in the bottom tank, and the mold according to any one of claims 1 to 6 is inserted upward from the bottom of the immersion pipe in the bottom tank into the bottom tank, with the bottom plate close to the bottom of the immersion pipe; (2) After the step (1) is completed, the bottom groove repair material is added through the alloy feeding port. After the bottom groove repair material is completely sintered or hardened, the mold is taken out, and the entire repair operation is completed.

8. The method for preparing a hot state repairing mold for the bottom groove of the vacuum chamber of a RH refining furnace according to claim 7, characterized in that: In step (1), the gap between the mold and the bottom of the immersion tube is filled with gunning material.

9. The method for preparing a hot state repairing mold for the bottom groove of the vacuum chamber of a RH refining furnace according to claim 7, characterized in that: The bottom groove repairing material in step (2) is any one of magnesium, magnesium-chromium and aluminum refractory materials.

10. The method for preparing a hot state repairing mold for the bottom groove of a vacuum chamber of a RH refining furnace according to claim 9, characterized in that: The bottom groove repair material comprises the following raw materials in percentage by mass: 20% 3-5mm fused magnesia sand, 20% 1-3mm fused magnesia sand, 25% 0.1-1mm fused magnesia sand, 19.5% 180-240 mesh fused magnesia sand, 13% asphalt and 2.5% fuel oil; Or the bottom groove repair material includes the following raw materials in percentage by mass: 20% 3-6mm plate corundum, 25% 1-3mm plate corundum, 25% 0.1-1mm plate corundum, 15.8% 280-325 mesh plate corundum, 8% alumina powder, 6% cement, 0.1% explosion-proof fiber and 0.1% water reducer.