Lower groove of RH refining furnace and segmented digging and repairing method of lower groove

Abstract

The invention provides a lower groove of an RH refining furnace and a segmented digging and repairing method of the lower groove. The lower groove comprises a groove shell and a lining, and the lining comprises a heat insulation lining, a permanent lining and a working lining which are sequentially arranged from outside to inside; the working lining comprises an upper working lining and a lower working lining, and the outer wall of the upper working lining is attached to the inner wall of the permanent lining; a secondary working lining for supporting the upper working lining is arranged between the lower working lining and the permanent lining; the secondary working lining used for assisting in supporting the upper working lining is additionally arranged on the outer side of the lower working lining, so that the secondary working lining can provide enough supporting force to assist in supporting the upper working lining when the lower working lining is subjected to segmented disassembly and replacement, and it is guaranteed that the lower working lining is independently and smoothly replaced; and the replacement cost is saved and the replacement period is shortened while the operation safety is ensured.

Description

Technical Field

[0001] The invention belongs to the field of RH refining furnaces, and in particular relates to a lower tank of a RH refining furnace and a segmented excavation and repair method of the lower tank. Background Art

[0002] RH refining furnace is a refining process equipment used to improve the quality of molten steel; the entire molten steel metallurgical reaction is carried out in a vacuum tank with a refractory lining; the vacuum tank includes an upper tank, a middle tank and a lower tank; during the RH vacuum refining process, molten steel is pumped into the vacuum tank under the action of vacuum pressure, and the molten steel liquid level is roughly located in the middle part of the lower tank; since the lower part of the lower tank is in direct contact with the molten steel, under the action of molten steel scouring and slag erosion, the melting loss rate of the lower working lining of the lower tank is much faster than the melting loss rate of the upper working lining of the lower tank; therefore, when the melting loss of the lower working lining of the lower tank is serious and cannot be partially repaired, the upper working lining of the lower tank can still be used normally. In order to ensure the safe use of the lower tank, the lower working lining of the lower tank needs to be replaced. However, if the lower working lining of the lower tank is replaced directly, it is very easy to cause the upper working lining of the lower tank to collapse, which poses a great safety hazard. Therefore, in order to ensure the safety of the operation, the entire working lining of the lower tank must be replaced as a whole, which greatly increases the replacement cost and replacement cycle. Summary of the invention

[0003] In view of the shortcomings of the prior art mentioned above, the technical problem to be solved by the present invention is to provide a lower tank of an RH refining furnace and a method for segmented excavation and repair of the lower tank, which adds a secondary working lining on the outside of the lower working lining for auxiliary support of the upper working lining; since the secondary working lining is located on the outside of the lower working lining, it will not directly contact with the molten steel during the entire refining process, so that when the lower working lining is dismantled and replaced in segments, the secondary working lining can provide sufficient supporting force to assist in supporting the upper working lining, thereby ensuring the smooth replacement of the lower working lining separately; while ensuring operational safety, it saves replacement costs and shortens the replacement cycle.

[0004] The present invention provides a lower tank of an RH refining furnace, comprising a tank shell and an inner lining, wherein the inner lining comprises a heat insulating lining, a permanent lining and a working lining which are arranged in sequence from the outside to the inside; the working lining comprises an upper working lining and a lower working lining, wherein the outer wall of the upper working lining is in contact with the inner wall of the permanent lining; a secondary working lining for supporting the upper working lining is arranged between the lower working lining and the permanent lining; by adding a secondary working lining for auxiliary support of the upper working lining on the outer side of the lower working lining, so that when the lower working lining is disassembled and replaced in sections, the secondary working lining can provide sufficient supporting force to auxiliary support the upper working lining, thereby ensuring smooth replacement of the lower working lining alone; while ensuring operation safety, the replacement cost is saved and the replacement cycle is shortened.

[0005] Preferably, the thickness H2 of the secondary working lining and the thickness H3 of the upper working lining satisfy: To ensure that during the dismantling of the lower working lining, there is a secondary working lining of sufficient thickness to support the upper working lining and ensure the stability of the upper working lining.

[0006] Preferably, the thickness H1 of the lower working lining, the thickness H2 of the secondary working lining and the thickness H3 of the upper working lining satisfy: 45mm≤H1+H2-H3≤105mm, so that the lower part of the lower trough has sufficient thickness of refractory material to improve the wear resistance of the lower part of the lower trough.

[0007] Preferably, the thickness of the upper working lining is equal to the thickness of the lower working lining.

[0008] Preferably, the height of the secondary working lining is determined according to the distance from the molten steel level in the lower tank to the tank bottom to ensure the optimization of replacement cost.

[0009] Preferably, each lining is constructed in a staggered manner to improve the integrity of each lining.

[0010] Preferably, the thermal insulation lining is built with calcium silicate boards, the permanent layer is built with wax stone bricks, and the secondary working lining, the upper working lining and the lower working lining are all built with magnesium spinel bricks.

[0011] The present invention also provides a segmented excavation and repair method for a lower trench, which is used to segmentally excavate and repair a lower working lining in the lower trench. The segmented excavation and repair method comprises:

[0012] S1. According to the positions of the two circulating flow pipes in the lower trough, the lower working lining is divided into two first arc-shaped areas and two second arc-shaped areas; the two first arc-shaped areas are arranged opposite to each other, and the two first arc-shaped areas are respectively located above the two circulating flow pipes;

[0013] S2, dismantle and replace the working bricks in the first arc-shaped area; then complete the dismantling and replacement of the working bricks in the second arc-shaped area.

[0014] As described above, the present invention relates to a lower tank of an RH refining furnace and a method for segmented excavation and repair of the lower tank, in which a secondary working lining for auxiliary support of the upper working lining is added to the outer side of the lower working lining, which not only increases the wear resistance of the lower part of the lower tank, but also because the secondary working lining is located on the outer side of the lower working lining, it will not directly contact with the molten steel during the entire refining process, so that when the lower working lining is disassembled and replaced in segments, the secondary working lining can provide sufficient supporting force to assist in supporting the upper working lining, thereby ensuring the smooth replacement of the lower working lining separately; while ensuring the safety of the operation, it saves the replacement cost and shortens the replacement cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is a three-dimensional diagram of the lower groove of the present invention.

[0016] Figure 2 It is a top view of the lower groove of the present invention.

[0017] Figure 3 It is a three-dimensional cross-sectional view of the lower groove of the present invention.

[0018] Figure 4 for Figure 3 A partial enlarged view at point A.

[0019] Figure 5 This is a schematic diagram of the second arc-shaped area of ​​the lower working lining after disintegration.

[0020] Figure 6 This is a schematic diagram of the first arc-shaped area of ​​the lower working lining after disintegration.

[0021] Description of reference numerals:

[0022] Tank shell 1 , thermal insulation lining 2 , permanent lining 3 , secondary working lining 4 , working lining 5 , upper working lining 51 , lower working lining 52 , first arc-shaped area 521 , second arc-shaped area 522 , circulating flow pipe 6 . DETAILED DESCRIPTION

[0023] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0024] It should be noted that the proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification, change in the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of the relative relationship, without substantially changing the technical content, should also be regarded as the scope of the implementation of the present invention.

[0025] like Figures 1 to 4As shown, a lower tank of an RH refining furnace of the present invention comprises a tank shell 1 and an inner lining located on the inner side of the tank shell 1; wherein the tank shell 1 is made of steel; the inner lining comprises a heat insulating lining 2, a permanent lining 3 and a working lining 5 which are arranged in sequence from the outside to the inside; the working lining 5 comprises an upper working lining 51 and a lower working lining 52, wherein the outer wall of the upper working lining 51 is in contact with the inner wall of the permanent lining 3, and a secondary working lining 4 for supporting the upper working lining 51 is arranged between the lower working lining 52 and the permanent lining 3; when the lower working lining 52 needs to be replaced (i.e., dismantled and rebuilt), the secondary working lining 4 can be used to auxiliary support the upper working lining 51, so as to avoid the upper working lining 51 from collapsing due to lack of support during the replacement of the lower working lining 52, thereby improving the safety of replacing the lower working lining 52.

[0026] Specifically, the thermal insulation lining 2 is built with fireproof thermal insulation boards such as calcium silicate boards or calcium silicate boards, the permanent lining 3 is built with wax stone bricks, and the working bricks used in the secondary working lining 4, the upper working lining 51 and the lower working lining 52 are made of refractory bricks such as magnesium spinel bricks or chrome bricks; when laying each lining, it is necessary to adopt a staggered joint method to ensure the integrity of each lining.

[0027] In order to ensure the support stability of the upper working lining 51, the thickness H2 of the secondary working lining 4 and the thickness H3 of the upper working lining 51 satisfy: The thickness H2 of the secondary working lining 4 of this embodiment is preferably set to

[0028] In order to ensure the wear resistance of the lower part of the lower groove, the thickness H1 of the lower working lining 52, the thickness H2 of the secondary working lining 4 and the thickness H3 of the upper working lining 51 satisfy: 45mm≤H1+H2-H3≤105mm; in this embodiment, the thickness of the upper working lining 51 and the thickness of the lower working lining 52 are preferably set to be equal to improve the refractory utilization rate of the lower working lining 52.

[0029] Specifically, the thermal insulation lining 2 is preferably built with calcium silicate board of 130mm*25mm*610mm (length*width*height); the wax stone brick of the permanent lining 3 is 110mm*50mm*230mm in size; the upper working lining 51 and the lower working lining 52 are preferably built with magnesium spinel bricks, which are wedge-shaped bricks with dimensions of 350mm*120mm / 150mm*100mm (length*front width / rear width*height); the secondary working lining 4 is preferably built with magnesium spinel bricks with dimensions of 110mm*50mm*260mm.

[0030] The height of the secondary working lining 4 is equal to that of the lower working lining 52, and its height can be determined according to the distance from the molten steel surface to the bottom of the tank in the actual refining state. After detection, it is found that the distance from the molten steel surface to the bottom of the tank is 900mm. Therefore, the height of the secondary working lining 4 and the lower working lining 52 is 900mm, which is equivalent to the height of 9 layers of wedge-shaped bricks.

[0031] like Figure 5 and Figure 6 As shown, the present invention also provides a segmented excavation and repair method for a lower trench, which is used to segmentally excavate and repair the lower working lining in the lower trench. The segmented excavation and repair method comprises:

[0032] S1. According to the positions of the two circulating flow pipes 6 in the lower trough, the lower working lining 52 is divided into two first arc-shaped areas 521 and two second arc-shaped areas 522; the two first arc-shaped areas 521 are arranged opposite to each other, and the two first arc-shaped areas 521 are respectively located above the two circulating flow pipes 6;

[0033] S2, dismantle and replace the working bricks in the first arc-shaped area 521; then complete the dismantling and replacement of the working bricks in the second arc-shaped area 522.

[0034] The present invention adds a secondary working lining 4 on the outer side of the lower working lining 52 for auxiliary support of the upper working lining 51. Without damaging the integrity of the lower tank, the secondary working lining 4 can be used as an auxiliary support member to auxiliary support the upper working lining 52, so as to facilitate the independent replacement of the lower working lining 52 and ensure that the upper working lining 52 will not collapse during the replacement of the lower working lining 52, thereby improving the safety of the operation. In addition, since the lower working lining 52 can be replaced independently, the utilization rate of the upper working lining 51 is improved, the replacement cost is saved and the replacement cycle is shortened.

[0035] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A lower tank of an RH refining furnace, comprising a tank shell and an inner lining, wherein the inner lining comprises an insulating lining, a permanent lining and a working lining arranged in sequence from the outside to the inside; It is characterized in that The working lining comprises an upper working lining and a lower working lining, wherein the outer wall of the upper working lining is in contact with the inner wall of the permanent lining; and a secondary working lining for supporting the upper working lining is arranged between the lower working lining and the permanent lining.

2. The lower tank of the RH refining furnace according to claim 1, It is characterized in that The thickness H2 of the secondary working lining and the thickness H3 of the upper working lining satisfy:

3. The lower tank of the RH refining furnace according to claim 2, It is characterized in that The thickness H1 of the lower working lining, the thickness H2 of the secondary working lining and the thickness H3 of the upper working lining satisfy: 45mm≤H1+H2-H3≤105mm.

4. The lower tank of the RH refining furnace according to claim 3, It is characterized in that The thickness of the upper working lining is equal to the thickness of the lower working lining.

5. A lower tank of a RH refining furnace according to any one of claims 1 to 4, It is characterized in that The height of the secondary working lining is determined according to the distance from the molten steel surface in the lower tank to the tank bottom.

6. The lower tank of the RH refining furnace according to claim 1, It is characterized in that Each lining is built with staggered joints.

7. The lower tank of the RH refining furnace according to claim 1, It is characterized in that The thermal insulation lining is built with calcium silicate boards, the permanent layer is built with wax stone bricks, and the secondary working lining, the upper working lining and the lower working lining are all built with magnesium spinel bricks.

8. A method for segmented excavation and repair of a lower trench, for segmented excavation and repair of a lower working lining in a lower trench as claimed in any one of claims 1 to 7, It is characterized in that The segmented excavation and repair method comprises: S1. According to the positions of the two circulating flow pipes in the lower trough, the lower working lining is divided into two first arc-shaped areas and two second arc-shaped areas; the two first arc-shaped areas are arranged opposite to each other, and the two first arc-shaped areas are respectively located above the two circulating flow pipes; S2, dismantle and replace the working bricks in the first arc-shaped area; then complete the dismantling and replacement of the working bricks in the second arc-shaped area.

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