JP6924635B2 - Refractory structure at the bottom corner of an electric furnace - Google Patents

Refractory structure at the bottom corner of an electric furnace Download PDF

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JP6924635B2
JP6924635B2 JP2017130598A JP2017130598A JP6924635B2 JP 6924635 B2 JP6924635 B2 JP 6924635B2 JP 2017130598 A JP2017130598 A JP 2017130598A JP 2017130598 A JP2017130598 A JP 2017130598A JP 6924635 B2 JP6924635 B2 JP 6924635B2
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side wall
brick
furnace
bricks
refractory
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JP2019015412A (en
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良樹 佐藤
良樹 佐藤
岡田　剛
剛 岡田
俊博 駿河
俊博 駿河
板楠　元邦
元邦 板楠
吉田　博
博 吉田
毅 成子
毅 成子
圭輔 柴崎
圭輔 柴崎
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Nippon Steel Corp
Krosaki Harima Corp
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Krosaki Harima Corp
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Description

本発明は、電気炉の炉底部から側壁部にかけての炉底コーナー部の耐火物構造に関する。 The present invention relates to a refractory structure of a furnace bottom corner portion from a furnace bottom portion to a side wall portion of an electric furnace.

スクラップ鉄などの炉内物を電極からの放電によって溶解する電気炉（アーク式電気炉）においては、鉄皮（側壁鉄皮及び炉底鉄皮）の内側に内張り材として耐火物がライニングされている。内張り材としては不定形耐火物又はれんががライニングされるが、耐用性を優先する場合にはれんががライニングされる。 In an electric furnace (arc type electric furnace) that melts the contents of the furnace such as scrap iron by electric discharge from the electrodes, a refractory material is lined inside the iron skin (side wall iron skin and furnace bottom iron skin) as a lining material. There is. Amorphous refractory or brick is lined as the lining material, but brick is lined when durability is prioritized.

れんががライニングされた電気炉においては、特に炉底部から側壁部にかけての炉底コーナー部に熱膨張などによって応力が掛かるため、その炉底コーナー部の損傷が他の部位よりも大きくなり、炉の寿命のネックとなる場合がある。 In an electric furnace lined with bricks, stress is applied to the bottom corners from the bottom to the side walls due to thermal expansion, etc., so the damage to the bottom corners is greater than that of other parts, and the furnace It may be a bottleneck in life.

その対策として、例えば特許文献１では図２に示すように、炉底れんがの膨張を吸収するために炉底れんがと側壁れんがとの間に不定形耐火物５０を配置する耐火物構造が開示されている。しかし、この耐火物構造では炉底れんがと側壁れんがとの間の距離が大きくなると不定形耐火物が溶鋼などの溶融物による先行溶損を受けやすくなり、炉底れんがと側壁れんがとの間の距離が小さいと応力を吸収することができず側壁れんがの損傷が大きくなってしまう問題がある。 As a countermeasure, for example, as shown in FIG. 2, Patent Document 1 discloses a refractory structure in which an amorphous refractory material 50 is arranged between the hearth brick and the side wall brick in order to absorb the expansion of the hearth brick. ing. However, in this refractory structure, if the distance between the bottom brick and the side wall brick is large, the amorphous refractory is susceptible to pre-melting damage due to melts such as molten steel, and between the bottom brick and the side wall brick. If the distance is small, stress cannot be absorbed and there is a problem that the damage to the side wall bricks becomes large.

また、特許文献１では図３に示すように、炉底コーナー部のれんがを炉内側に中心をもつ放射線方向に沿った状態に積み上げる耐火物構造も開示されている。しかし、この耐火物構造では、膨張代が確保されていないため膨張の逃げ代がなく、依然として炉底コーナー部のれんがの損傷が問題となる。 Further, as shown in FIG. 3, Patent Document 1 also discloses a refractory structure in which bricks at the corners of the furnace bottom are piled up in a state along the radiation direction having a center inside the furnace. However, in this refractory structure, since the expansion allowance is not secured, there is no escape allowance for expansion, and damage to the brick at the corner of the furnace bottom still becomes a problem.

特開平１１−１７３７６４号公報Japanese Unexamined Patent Publication No. 11-173764

本発明が解決しようとする課題は、電気炉の炉底コーナー部の損傷を抑制することにある。 An object to be solved by the present invention is to suppress damage to the bottom corner of an electric furnace.

上記課題を解決するために本発明は、次の耐火物構造を提供する。
「電気炉の炉底部から側壁部にかけての炉底コーナー部の耐火物構造において、
最下段及びその上段の側壁れんがのうち少なくとも前記最下段の側壁れんがは炉底れんがに面接触させるとともに、炉底れんがに面接触しているすべての側壁れんがと側壁鉄皮との間には不定形耐火物を充填し、
炉底れんがに面接触しない側壁れんがと炉底れんがとの間には不定形耐火物を充填するとともに、当該側壁れんがは水平方向に幅１０〜５０ｍｍの目地を介して複数個に分割して配置されていることを特徴とする電気炉の炉底コーナー部の耐火物構造。」 In order to solve the above problems, the present invention provides the following refractory structure.
"In the refractory structure of the bottom corner of the electric furnace from the bottom to the side wall,
Together with at least the side wall bricks of the lowermost is brought into surface contact with the furnace bottom bricks of the bottom and side wall bricks of the upper, between the all side wall bricks and the side wall furnace shell that is in surface contact with the furnace bottom bricks not Filled with standard refractory,
An irregular refractory is filled between the side wall bricks that do not come into surface contact with the bottom bricks, and the side wall bricks are divided into a plurality of pieces in the horizontal direction through joints having a width of 10 to 50 mm. The refractory structure of the bottom corner of the electric furnace, which is characterized by being bricked. "

本発明の耐火物構造によれば、電気炉の炉底コーナー部の損傷が抑制されるため電気炉の寿命が延長する。 According to the refractory structure of the present invention, damage to the bottom corner of the electric furnace is suppressed, so that the life of the electric furnace is extended.

本発明の一実施形態に係る電気炉の炉底コーナー部の耐火物構造を示す縦断面図である。It is a vertical cross-sectional view which shows the refractory structure of the furnace bottom corner part of the electric furnace which concerns on one Embodiment of this invention. 従来の電気炉の炉底コーナー部の耐火物構造を示す縦断面図である（特許文献１の図４に対応）。It is a vertical cross-sectional view which shows the refractory structure of the furnace bottom corner part of the conventional electric furnace (corresponding to FIG. 4 of Patent Document 1). 従来の電気炉の炉底コーナー部の耐火物構造を示す縦断面図である（特許文献１の図１に対応）。It is a vertical cross-sectional view which shows the refractory structure of the furnace bottom corner part of the conventional electric furnace (corresponding to FIG. 1 of Patent Document 1).

図１に本発明の一実施形態に係る電気炉の炉底コーナー部１の耐火物構造の縦断面図を示す。 FIG. 1 shows a vertical cross-sectional view of a refractory structure of a furnace bottom corner portion 1 of an electric furnace according to an embodiment of the present invention.

炉底鉄皮１２の上に不定形耐火物としてスタンプ材６が施工され、スタンプ材６の上にはパーマれんが２が３層施工され、さらにパーマれんが２の上に炉底れんが４がライニングされている。側壁鉄皮１１の内側にはパーマれんが２が施工され、パーマれんが２の内側に側壁れんが３が施工されている。また、側壁れんが３と炉底れんが４との間や、側壁れんが４とパーマれんが２（側壁鉄皮１１）との間にはスタンプ材６（不定形耐火物）が施工（充填）されている。 Stamp material 6 is installed on the bottom iron skin 12 as an irregular refractory, three layers of perm brick 2 are installed on the stamp material 6, and furnace bottom brick 4 is lined on the perm brick 2. ing. Perm brick 2 is installed inside the side wall iron skin 11, and side wall brick 3 is installed inside the side wall brick 2. In addition, a stamp material 6 (amorphous refractory) is installed (filled) between the side wall brick 3 and the furnace bottom brick 4 and between the side wall brick 4 and the perm brick 2 (side wall iron skin 11). ..

最下段の側壁れんが３１の炉底部側の側面は、最も外側の炉底れんが４１の側面に当接して面接触しており、最下段の側壁れんが３１の底面は、炉底側のパーマれんが２とスタンプ材６の上に配置されている。また、最下段の側壁れんが３１の側壁鉄皮１１側の側面と側壁部側のパーマれんが２（側壁鉄皮１１）との間にもスタンプ材６が施工（充填）されている。 The side surface of the bottom side wall brick 31 on the bottom side is in contact with the side surface of the outermost side wall brick 41, and the bottom surface of the bottom side wall brick 31 is a perm brick 2 on the bottom side. And is placed on the stamp material 6. Further, the stamp material 6 is also installed (filled) between the side surface of the lowermost side wall brick 31 on the side wall iron skin 11 side and the perm brick 2 (side wall iron skin 11) on the side wall portion side.

最下段の側壁れんが３１の上には下から２段目の側壁れんがとして、水平方向に２個に分割した内側側壁れんが３２と外側側壁れんが３３が目地５を介して配置されている。目地５には目地材として不定形耐火物が充填されている。下から３段目から５段目までも同様な構造となっている。また、下から２段目から５段目の側壁れんが（炉底コーナー部を構成する側壁れんがのうち炉底れんがに面接触しない側壁れんが）と炉底れんがとの間にはスタンプ材６（不定形耐火物）が施工（充填）されている。 On the lowermost side wall brick 31, as the second side wall brick from the bottom, the inner side wall brick 32 and the outer side wall brick 33 divided into two in the horizontal direction are arranged via the joint 5. The joint 5 is filled with an amorphous refractory material as a joint material. The same structure is used for the third to fifth steps from the bottom. In addition, there is a stamp material 6 (non-existent) between the side wall bricks in the second to fifth stages from the bottom (side wall bricks that do not come into surface contact with the hearth bricks among the side wall bricks that make up the corners of the hearth) and the hearth bricks. Standard refractory) is constructed (filled).

以上のように本実施形態では、下から２段目から５段目の側壁れんが３（炉底コーナー部を構成する側壁れんがのうち炉底れんがに面接触しない側壁れんが）は、目地５を介して水平方向に２個配置、すなわち従来の側壁れんがが目地５で分割された状態で配置されている。この目地５によって炉底れんが４の膨張を吸収することができる。このため炉底れんがと側壁れんがとの間のスタンプ材６（不定形耐火物）の施工量を減すことができ、スタンプ材６の局部溶損による炉底コーナー部の損傷を抑制することができる。さらに、特許文献１に記載されているように、炉底れんがの熱膨張によって曲げモーメントが側壁れんがに掛かっても、分割された側壁れんがの長さは短いため曲げモーメントによる引張応力を抑制することができ、側壁れんがの割れを防止できる。 As described above, in the present embodiment, the side wall bricks 3 of the second to fifth stages from the bottom (the side wall bricks constituting the furnace bottom corner portion that do not come into surface contact with the furnace bottom brick) are routed through the joint 5. Two pieces are arranged in the horizontal direction, that is, the conventional side wall bricks are arranged in a state of being divided by joints 5. The joint 5 can absorb the expansion of the bottom brick 4. Therefore, the amount of stamp material 6 (amorphous refractory) applied between the bottom brick and the side wall brick can be reduced, and damage to the bottom corner due to local melting damage of the stamp material 6 can be suppressed. can. Further, as described in Patent Document 1, even if the bending moment is applied to the side wall brick due to the thermal expansion of the furnace bottom brick, the length of the divided side wall brick is short, so that the tensile stress due to the bending moment is suppressed. And can prevent the side wall bricks from cracking.

また、最下段の側壁れんが３１は最も外側の炉底れんが４１に面接触しているため、もし炉内側のスタンプ材６が異常損耗したとしても溶鋼の漏れを防止することができる。さらに、最下段の側壁れんが３１と側壁部側のパーマれんが２（側壁鉄皮１１）との間にはスタンプ材６（不定形耐火物）が充填されているので、最下段の側壁れんが３１においても炉底れんが４の膨張を吸収することができる。 Further, since the lowermost side wall brick 31 is in surface contact with the outermost furnace bottom brick 41, leakage of molten steel can be prevented even if the stamp material 6 inside the furnace is abnormally worn. Further, since the stamp material 6 (amorphous refractory) is filled between the lowermost side wall brick 31 and the side wall side perm brick 2 (side wall iron skin 11), the lowermost side wall brick 31 Can also absorb the expansion of the bottom brick 4.

ここで、本発明において目地５の幅は１０〜５０ｍｍとする。目地５の幅が１０ｍｍ未満では膨張吸収が不十分となり、炉底コーナー部が損傷しやすくなる。目地５の幅が５０ｍｍを超えると、結果としてれんがの長さが不十分となって炉底コーナー部が損傷しやすくなる。本実施形態では下から２段目と３段目における目地５の幅は３０ｍｍ、下から４段目と５段目における目地５の幅は２０ｍｍとした。なお、目地の幅とは、図１において内側側壁れんがと外側側壁れんがの対向する側面間の距離Ａのことである。 Here, in the present invention, the width of the joint 5 is 10 to 50 mm. If the width of the joint 5 is less than 10 mm, expansion and absorption will be insufficient, and the corners of the bottom of the furnace will be easily damaged. If the width of the joint 5 exceeds 50 mm, the length of the brick becomes insufficient as a result, and the corners of the bottom of the furnace are easily damaged. In the present embodiment, the width of the joint 5 in the second and third steps from the bottom is 30 mm, and the width of the joint 5 in the fourth and fifth steps from the bottom is 20 mm. The width of the joint is the distance A between the facing side surfaces of the inner side wall brick and the outer side wall brick in FIG.

また、本発明において目地５に充填する目地材（不定形耐火物）としては、一般的に目地材として使用されているモルタル、プラスチック、スタンプ材等を使用することができるが、れんがの熱膨張により発生する応力を吸収しやすい材料の選択を優先することが好ましい。本実施形態では、Ｃが７質量％、ＭｇＯが８６質量％のマグネシアカーボン質のスタンプ材を使用した。側壁れんが３と炉底れんが４との間等に充填されるスタンプ材６も、Ｃが７質量％、ＭｇＯが８６質量％のマグネシアカーボン質とした。本発明において側壁れんが３と炉底れんが４との間等に充填される不定形耐火物としては、スタンプ材に代えてプラスチック、キャスタブル等を使用することもできるが、施工性と耐用性を優先する場合にはスタンプ材を使用することが好ましい。 Further, as the joint material (amorphous refractory) to be filled in the joint 5 in the present invention, mortar, plastic, stamp material or the like generally used as the joint material can be used, but thermal expansion of bricks can be used. It is preferable to give priority to the selection of a material that easily absorbs the stress generated by the above. In this embodiment, a magnesia carbonaceous stamp material having 7% by mass of C and 86% by mass of MgO was used. The stamp material 6 to be filled between the side wall brick 3 and the furnace bottom brick 4 was also made of magnesia carbon having 7% by mass of C and 86% by mass of MgO. In the present invention, as the amorphous refractory to be filled between the side wall brick 3 and the furnace bottom brick 4, plastic, castable, etc. may be used instead of the stamp material, but workability and durability are prioritized. When this is done, it is preferable to use a stamp material.

本発明において、れんが（パーマれんが２、側壁れんが３及び炉底れんが４）の材質は限定されない。本実施形態では、パーマれんが２としてはＭｇＯが９５質量％の焼成れんがを使用し、側壁れんが３及び炉底れんが４としては、Ｃが１５質量％、ＭｇＯが８３質量％のマグネシアカーボンれんがを使用した。 In the present invention, the material of the brick (2 perm bricks, 3 side wall bricks and 4 hearth bricks) is not limited. In this embodiment, as the perm brick 2, calcined brick with 95% by mass of MgO is used, and as the side wall brick 3 and the furnace bottom brick 4, magnesia carbon brick with 15% by mass of C and 83% by mass of MgO is used. bottom.

本発明において、炉底れんがと面接触する側壁れんが３１と側壁鉄皮１１との間に充填される不定形耐火物（スタンプ材６）の幅（水平方向の長さ）は、５０ｍｍ以上であることが好ましく、本実施形態では約２００ｍｍとした。 In the present invention, the width (horizontal length) of the amorphous refractory (stamp material 6) filled between the side wall brick 31 and the side wall iron skin 11 which are in surface contact with the furnace bottom brick is 50 mm or more. It is preferably about 200 mm in this embodiment.

なお、本実施形態において最下段の側壁れんが３１は水平方向に分割しなかったが、２段目から５段目の側壁れんがと同様に、水平方向に複数個に分割してもよい。この場合、最下段の側壁れんがのうち最も炉底部側の側壁れんがを炉底れんがに面接触させる。また、本実施形態では、最下段の側壁れんが３１のみを炉底れんがに面接触させるようにしたが、下から２段目の側壁れんがも炉底れんがに面接触させるようにしてもよい。 Although the lowermost side wall brick 31 was not divided in the horizontal direction in the present embodiment, it may be divided into a plurality of side wall bricks in the horizontal direction in the same manner as the second to fifth side wall bricks. In this case, the side wall brick on the bottom side of the bottom side wall brick is brought into surface contact with the bottom wall brick. Further, in the present embodiment, only the lowermost side wall brick 31 is brought into surface contact with the furnace bottom brick, but the second side wall brick from the bottom may also be brought into surface contact with the furnace bottom brick.

図１の炉底コーナー部の耐火物構造を有する電気炉を使用したところ、従来の図２の耐火物構造の場合と比較して１５％寿命が延びることを確認した。 When an electric furnace having a refractory structure at the corner of the bottom of the furnace in FIG. 1 was used, it was confirmed that the life was extended by 15% as compared with the case of the conventional refractory structure in FIG.

１ 炉底コーナー部
１１ 側壁鉄皮
１２ 炉底鉄皮
２ パーマれんが
３ 側壁れんが
３１ 最下段の側壁れんが
３２ 内側側壁れんが
３３ 外側側壁れんが
４ 炉底れんが
４１ 最も外側の炉底れんが
５ 目地
６ スタンプ材（不定形耐火物） 1 Furnace bottom corner 11 Side wall iron skin 12 Furnace bottom iron skin 2 Permanent brick 3 Side wall brick 31 Bottom side wall brick 32 Inner side wall brick 33 Outer side wall brick 4 Furnace bottom brick 41 Outermost furnace bottom brick 5 Joint 6 Stamp material (Atypical fireproof material)

Claims (1)

電気炉の炉底部から側壁部にかけての炉底コーナー部の耐火物構造において、
最下段及びその上段の側壁れんがのうち少なくとも前記最下段の側壁れんがは炉底れんがに面接触させるとともに、炉底れんがに面接触しているすべての側壁れんがと側壁鉄皮との間には不定形耐火物を充填し、
炉底れんがに面接触しない側壁れんがと炉底れんがとの間には不定形耐火物を充填するとともに、当該側壁れんがは水平方向に幅１０〜５０ｍｍの目地を介して複数個に分割して配置されていることを特徴とする電気炉の炉底コーナー部の耐火物構造。 In the refractory structure at the bottom corner of the electric furnace from the bottom to the side wall,
Together with at least the side wall bricks of the lowermost is brought into surface contact with the furnace bottom bricks of the bottom and side wall bricks of the upper, between the all side wall bricks and the side wall furnace shell that is in surface contact with the furnace bottom bricks not Filled with standard refractory,
An irregular refractory is filled between the side wall bricks that do not come into surface contact with the bottom bricks, and the side wall bricks are divided into a plurality of pieces in the horizontal direction through joints having a width of 10 to 50 mm. The refractory structure of the bottom corner of the electric furnace, which is characterized by being bricked.
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