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

Abstract

The utility model discloses a hot-state repairing die for a bottom groove of a vacuum chamber of an RH (Ruhrstahl Heraeus) refining furnace, which relates to the technical field of vacuum smelting furnaces and comprises a base plate, a straight section and a conical section which are sequentially arranged 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.

Description

TECHNICAL FIELD

[0001] The utility model relates to vacuum refining furnace technical field, concretely relates to a RH refining furnace vacuum chamber bottom groove hot state repair mould. BACKGROUND

[0002] With the development of science and technology and the rapid growth of economy, the demand for high-quality clean steel also increases day by day. RH refining furnace is one of important high-temperature devices for smelting high-quality clean steel, which has the functions of dehydrogenation, decarburization, deoxidation, desulfurization, precise control of molten steel composition and temperature, inclusion control and removal, etc. With the development of RH vacuum smelting technology, the varieties suitable for smelting have greatly increased, and RH refining equipment has become indispensable for smelting high-grade pipeline, ultra-low carbon steel, silicon steel and other high-value-added steel grades. This also puts forward higher and higher requirements for the performance of RH refractory materials.

[0003] At present, most steel and iron metallurgical enterprises commonly use magnesium-chrome refractory materials as the inner lining of the working layer of RH refining furnace. However, during use, the RH furnace circulation pipe, immersion pipe and bottom groove are directly in contact with molten steel, and are subjected to scouring by molten steel, erosion and melting loss by steel slag, and thermal spalling caused by thermal shock, which makes the bottom of the RH bottom groove and the joint part of the circulation pipe often be suddenly broken or severely eroded during use, and be taken out of service at a low age, while the working lining of other parts is intact. This not only disrupts the production plan rhythm of the steel plant, but also causes waste of refractory material cost.

[0004] Therefore, it is a technical problem to be solved in the field to provide an RH vacuum smelting bottom groove hot state repair mould to compensate for the situation of sudden breakage or severe erosion during use, prolong the service life of the RH bottom groove, save the use of refractory materials, and reduce costs. CONTENT OF THE UTILITY MODEL

[0005] The utility model mainly aims at the problem of sudden breakage or severe erosion of the joint part of the RH refining furnace vacuum chamber bottom groove and the circulation pipe during use, and provides an RH refining furnace vacuum chamber bottom groove hot state repair mould.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0007] An RH refining furnace vacuum chamber bottom groove hot state repair mould, the mould comprises a bottom disc, a straight section and a tapered section from bottom to top in sequence;

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

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

[0010] The top of the straight section is connected with the conical section, which is triangular conical, and the diameter of the bottom of the conical section is the same as the diameter of the top of the straight section.

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

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

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

[0014] Preferably, the straight section is cylindrical and / or circular truncated conical.

[0015] Preferably, the bottom disc and the straight section are made of a steel plate with a thickness of 5-20mm, and the bottom disc is made of a steel plate with a thickness of 5-20mm.

[0016] A hot-state repairing method for a bottom slot of a vacuum chamber of an RH refining furnace, comprising the following steps:

[0017] (1) After the RH vacuum operation is completed, the residual steel in the bottom slot is completely melted by heating, the mold is inserted into the inside of the bottom slot from the bottom of the immersed pipe in the bottom slot, and the bottom disc is tightly attached to the bottom of the immersed pipe;

[0018] (2) After the step (1) is completed, the bottom slot repairing material is poured through the alloy feeding port, and after the bottom slot repairing material is completely sintered or hardened, the mold is removed, and the whole repairing operation is completed.

[0019] Preferably, the gap between the mold and the bottom of the immersed pipe in the step (1) is filled by using a gunning material.

[0020] Preferably, the gunning material is a common magnesia gunning material.

[0021] Preferably, the bottom slot repairing material in the step (2) is any one of magnesia, magnesia-chrome and alumina refractory materials, which can be a common castable or a high-temperature self-flow repairing material mainly based on a pitch bonding system.

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

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

[0024] Preferably, the water reducing agent is at least one of sodium tripolyphosphate, sodium hexametaphosphate or polycarboxylate superplasticizer.

[0025] Compared with the prior art, the utility model has the following beneficial effects:

[0026] The repairing mold provided by the utility model can achieve the purpose of repairing the bottom groove only during the intermittent period of RH refining furnace vacuum operation, and does not need to perform the operation mode of brick digging, replacement or filling through the RH bottom groove offline operation, so that the service life of the RH bottom groove circulation pipe and the immersion pipe is improved, the vacuum chamber turnover cycle is shortened, the amount of refractory material is reduced, and the production cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and the drawings in the description are only the embodiments of the utility model.

[0028] Figure 1 It is the mold structure diagram of the embodiment 1 of the utility model;

[0029] Figure 2 It is the damage schematic diagram of the RH bottom groove of the utility model embodiment;

[0030] Figure 3 It is the mold assembly schematic diagram of the RH bottom groove of the utility model embodiment;

[0031] Figure 4 It is the mold structure diagram of the embodiment 2 of the utility model. DETAILED DESCRIPTION

[0032] The embodiments of the utility model are described below, the examples of the embodiments are shown in the drawings, the embodiments described with reference to the drawings are exemplary, and are intended to explain the utility model, and are not understood as the limitation of the utility model.

[0033] Embodiment 1

[0034] As 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 the immersion pipe in the RH refining furnace bottom groove is 750mm, and the height H1 of the original circulation pipe and the immersion pipe is 1650mm.

[0035] As Figure 1 The utility model provides a RH refining furnace vacuum chamber bottom groove hot state repair mould: mould is from below to above in proper order bottom disc 1, straight section 2 and taper section 3, wherein,

[0036] Taper section 3 is triangular pyramid, is rolled into by 5-20mm thick steel plate, and height H3 is 150mm;

[0037] Straight section 2 is composed of cylinder and circular truncated cone, is rolled into by 5-20mm thick steel plate, and straight section 2 height size H2 is 1800mm;The diameter of the bottom surface of circular truncated cone and cylinder is same, and the bottom surface of circular truncated cone and the upper surface of cylinder are welded;The diameter D2 of cylinder is 680mm, and the height is 1650mm, and the top diameter of circular truncated cone is 630mm;The top surface of circular truncated cone and the bottom surface of taper section 3 are welded;

[0038] Bottom disc 1 is discoid, is cut into by 20-25mm thick steel plate, and bottom disc 1 is welded in the middle on the bottom of straight section 2 as shown in the figure; Figure 1

[0039] A RH refining furnace vacuum chamber bottom groove hot state repair method, specifically comprising the following steps:

[0040] (1) immediately melt all residual steel in the bottom groove after the RH refining furnace vacuum operation is finished, to ensure that the repaired part has no residual steel, slag and other residues;The above-mentioned mould is fixed on the lifting platform, and the distance between the two mould centers is consistent with the distance between the upper and lower immersion tube centers, and the mould is inserted into the bottom groove from the bottom of the immersion tube by the lifting platform, and the mould bottom disc is close to the bottom of the immersion tube (such as Figure 3 ), and the gap between the mould and the bottom of the immersion tube is filled by using ordinary magnesium injection material;

[0041] (2) after completing step (1), the bottom groove repair material is put into through the alloy feeding port in the form of a bag, and the amount is determined according to the damage amount, and after the bottom groove repair material is completely sintered, the sintering time is 15min, and the mould is pulled out by the lifting platform after waiting for 20min, and the whole repair operation is completed, wherein the specific components and ratio of the bottom groove repair material are shown in table 1: through the melting of asphalt, the high-temperature self-flow repair material flows into the required repair site to achieve the repair purpose.

[0042] Table 1 bottom groove repair material raw material ratio

[0043] Raw material Specification Proportion, % 96 ordinary fused magnesite 3-5 mm 20 96 ordinary fused magnesite 1-3 mm 20 96 ordinary fused magnesite 0.1-1 mm 25 96 ordinary fused magnesite 180-240 mesh 19.5 Pitch 0-1 mm 13 Fuel oil 2.5

[0044] Example 2

[0045] As 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 circulating pipe and immersion pipe in the bottom tank of its RH refining furnace is 750mm, and the height H1 of the original circulating pipe and immersion pipe is 1650mm.

[0046] like Figure 4 This utility model provides a hot repair mold for the bottom groove of the vacuum chamber of an RH refining furnace: the mold consists of a base plate 1, a straight section 2, and a conical section 3 from bottom to top.

[0047] Conical segment 3 is triangular pyramidal in shape, rolled from 5-20mm thick steel plate, with a height H3 of 150mm;

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

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

[0050] A method for hot repair of the bottom tank of the vacuum chamber in an RH refining furnace, specifically including the following steps:

[0051] (1) Immediately after the vacuum operation of the RH refining furnace is completed, heat up to completely melt away the residual steel in the bottom tank, ensuring that there is no residual steel, slag, or other residue in the repaired area; fix the above mold on the lifting platform, with the center distance between the two molds consistent with the center distance between the upper and lower impregnation tubes, and insert the mold into the bottom tank from the bottom of the impregnation tube upwards through the lifting platform, with the mold base tightly against the bottom of the impregnation tube (e.g., Figure 3 The gap between the mold and the bottom of the impregnation tube is filled with ordinary magnesium spray filler.

[0052] (2) After completing step (1), the bottom groove repair material is put into the alloy feeding port in the form of a small bag. The amount of material added depends on the amount of damage. After the bottom groove repair material has 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 and stirred. The amount of water added is 5.5-8.5%. The material is put into a small bag and put into the bottom groove through the alloy feeding port. The material flows into the area to be repaired due to its own fluidity.

[0053] Table 2 Raw material ratio for bottom trench repair material

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

[0055] Implementation results:

[0056] 1) save time, shorten the vacuum chamber turnover cycle, RH refining furnace vacuum operation interval can achieve repair RH refining furnace bottom tank, the entire construction process 1h can complete the repair work, the original construction repair method needs at least 3 days to put into production operation;

[0057] 2) can improve the service life of RH refining furnace bottom tank, the original service life of a pair of circulation pipe, immersion pipe is 65-70 times; using this repair method, the service life of a pair of circulation pipe, immersion pipe is 95-100 times;

[0058] 3) without through RH refining furnace bottom tank off-line operation for digging brick, replacement or filling operation mode, both reduce labor intensity, and reduce cost, can reduce the average each set of RH bottom tank more than 30 million yuan investment.

[0059] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A hot repair mold for a bottom slot of a vacuum chamber of an RH refining furnace, characterized by, The mold comprises a bottom disc, a straight section and a taper section from bottom to top; The diameter of the straight section is 50-100mm smaller than the inner diameter of the immersed pipe and the circular flow pipe in the original bottom slot; The bottom disc is connected with the bottom of the straight section, and the width of the bottom disc is greater than the diameter of the bottom surface of the straight section; The taper section is connected with the top of the straight section, is triangular pyramid, and the diameter of the bottom surface of the taper section is the same as the diameter of the top surface of the straight section.

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

3. The hot repair mold for the bottom slot of the vacuum chamber of the RH refining furnace according to claim 1, characterized in that, The height of the taper section is 200-400mm.

4. The hot repair mold for the bottom slot of the vacuum chamber of the RH refining furnace according to claim 1, characterized in that, The straight section is cylindrical and / or circular frustum.

5. The hot repair mold for the bottom slot of the vacuum chamber of the RH refining furnace according to claim 1, characterized in that, The height of the straight section is 100-350mm higher than the total height of the immersed pipe and the circular flow pipe in the original bottom slot.

6. The hot repair mold for the bottom slot of the vacuum chamber of the RH refining furnace according to claim 1, characterized in that, The bottom disc and the straight section are prepared by using a steel plate with a thickness of 5-20mm, and the bottom disc is prepared by using a steel plate with a thickness of 5-20mm.

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