JP4505355B2 - Blast furnace repair method - Google Patents

Description

  The present invention relates to a method for repairing a blast furnace, and more particularly to a method for repairing the bottom of a blast furnace body.

  Conventionally, blast furnace refurbishment requires a long period of 4 to 5 months, including the dismantling of the furnace body, the construction of the refractory in the furnace, and the installation of the cooling system. From this point of view, it has been strongly demanded to renovate the blast furnace in the shortest time.

  In addition, the number of operating blast furnaces is on the decline, and there are many steelworks operating single-unit blast furnaces, and there is a strong demand for renovation in the short term. Among them, various repair methods, dismantling / removal methods, and installation methods have been proposed for the repair method of the furnace bottom.

  For example, in Japanese Patent Laid-Open No. 5-222420, a fluid film of compressed gas is formed between a furnace bottom and a blast furnace base, and the furnace bottom is held horizontally by a hydraulic jack through the fluid film. A blast furnace refurbishing method has been proposed in which the moving resistance is reduced and the bottom of the furnace is separated and removed.

  In addition, JP-A-2001-59109, JP-A-2001-81508, JP-A-2001-131617, JP-A-2001-207204, etc. have a plurality of through holes in the blast furnace foundation concrete directly under the furnace bottom. After the dawn, a proposal has been made to use a through hole to separate the furnace bottom from the blast furnace foundation concrete with a wire saw, etc., and to install a mechanism for floating the furnace bottom in the horizontal through hole to enable horizontal drawing.

  Also, in JP 2002-339007 A, a horizontal through hole is made in a blast furnace foundation concrete, and after horizontal cutting with a wire saw, a gap is formed by lifting the furnace bottom through this cut surface, and using this gap The horizontal movement means is arranged, and the bottom of the furnace is thereby moved laterally at a time. In order to make the movement successful, it is necessary to securely arrange the horizontal movement means in the gap. It is necessary to secure a horizontal section cut by a saw.

  The technology disclosed in Japanese Patent Laid-Open No. 2002-339007 will be briefly described with reference to FIGS. The blast furnace 10 includes a blast furnace foundation concrete 11, a spread beam 12 provided on the foundation 11, and a blast furnace main body 13 provided on the spread beam 12. The blast furnace 10 and the furnace top equipment provided in the upper part thereof are supported by a furnace body rod 14 including pillars 22 erected at four locations around the blast furnace, and a center hole jack 50 on which the blast furnace body 13 is suspended. Install suspension means such as.

  The laying beam 12 provided on the blast furnace foundation concrete 11 includes a large number of H-shaped steels arranged in parallel, cooling pipes installed between the H-shaped steels, and a flat or circular shape installed on the top of the H-shaped steel. It consists of the bottom plate of the furnace. The upper side of the laying beam 12 that reaches a high temperature is cooled by the cooling pipe or the like, and the temperature rise of the blast furnace foundation concrete 11 below the laying beam 12 is restricted.

  The blast furnace body 13 is formed in a cylindrical shape and is erected and welded to the upper part of the furnace bottom plate. The outer side of the blast furnace body 13 is covered with an iron skin 29, and a number of stave coolers 30 are arranged on the inner side. A furnace bottom building tile layer 31 made of a refractory is formed on the inner lower portion of the blast furnace body 13. After the blast furnace 10 is blown up, the cooled and solidified residue remains on the top of the furnace bottom tile layer 31.

The procedure of the dismantling method for the blast furnace bottom 36 will be described with reference to FIG. In the cutting process of the blast furnace bottom part 36, a horizontal cutting part 49 divided in advance into cutting sections 37, 38, 39 and 40 is planned in the blast furnace basic concrete 11 below the floor beam 12 cut from the blast furnace main body 13.
As shown in FIG. 8B, the cutting sections 37 to 40 are formed in a sector shape having a central angle of 90 degrees that is point-symmetric and line-symmetric with respect to the center of the blast furnace body 13. The cutting section is not limited to such a sector shape, but can be a rectangular section sliced horizontally.

  The boundaries 41, 42, 43, 44 of each cutting section 37-40 are separated by core boring performed from the side using a drilling machine (not shown), and adjacent boundaries 41, 42, and boundary 43, which are perforated. , 44 are respectively inserted with wire saws 45, 46, and by operating them simultaneously, the opposing cutting sections 37, 39 can be cut simultaneously so that the blast furnace body 13 maintains a standing state at a right angle. it can. Next, a flexible hose is inserted into the cut portion, a liquid release material is applied to the upper and lower cut surfaces, and then the cut surface grout material is filled and the load of the blast furnace body is supported by the hardened grout material.

  By repeatedly performing the series of operations, the step of separating the bottom of the furnace can be performed even during operation of the blast furnace 10.

  In the furnace body cutting step, after cutting the horizontal cutting part 49, the blast furnace 10 is blown up, the brackets 52, 53 are welded to the upper part and the lower part of the blast furnace main body 13, and the center hole jacks 50, 51 are attached. The upper mantel 34 and the blast furnace bottom 36 including the floor beam 12 and the furnace bottom mantel 35 are supported. Next, by horizontally cutting the lower portion 15 from the tuyere level of the blast furnace main body 13, the blast furnace main body 13 is separated into an upper mantel 34 and a furnace bottom mantel 35 containing the remaining roof tiles and residue 33. At the same time, the surrounding facilities are dismantled.

  In the removal process of the blast furnace bottom 36, the blast furnace bottom 36 is raised using the center hole jack 51 in a state where the upper mantel 34 is lifted using the center hole jack 50. The blast furnace bottom portion 36 can be lifted away from the lower portion of the blast furnace foundation concrete 11 with a small force by the action of the release material applied with the horizontal cutting portion 49. Alternatively, it is possible to raise the furnace bottom with a hydraulic jack.

Next, a carriage 58 that can travel on the rail member 55 constituting the lateral movement means is disposed on the cut surface of the blast furnace bottom 36, the blast furnace bottom 36 is lowered onto the carriage 58, and is moved laterally using a winch or the like (not shown). Then, it is moved out of the furnace body 14 and further transported by the heavy material transport cart 57.
JP-A-5-222420 JP 2001-59109 A JP 2001-81508 A JP 2001-131617 A JP 2001-207204 A JP 2002-339007 A

According to conventional techniques such as Japanese Patent Application Laid-Open No. 2002-339007, the blast furnace main body is separated into an upper mantel and a blast furnace bottom including a floor beam and a furnace bottom mantel, and the blast furnace foundation concrete below the blast furnace bottom is horizontally oriented using a wire saw. After the blast furnace bottom is lifted, the bottom of the blast furnace is lifted to form a gap in the cut, and the lateral movement means is arranged using this gap to move the bottom of the blast furnace in a lump to repair the blast furnace body. There is an advantage that can be done in a short period of time, but in order for the movement to be successful, it is necessary to secure a cutting plane in order to securely arrange the lateral movement means in the gap, and in this respect the blast furnace bottom is raised In this case, there is a problem that the concrete deteriorated by high heat may be peeled off in the gaps and hinder the cutting plane.

The present invention is to solve the above-mentioned problems, and will be further described with reference to FIGS.
Each figure shows a blast furnace foundation for carrying out the repair method of the present invention. In FIG. 2, a bottom step beam 63 made of H-shaped steel is installed in a recess 62 formed on the upper surface of the blast furnace foundation concrete 61, and a grout 64 is formed in the recess 62 so as to fill a gap between the bottom step beam 63. Filled. A first stage beam 65 is disposed above the lowermost stage beam 63, a second stage beam 68 is disposed on the first stage beam 65, and a furnace bottom plate 69 is disposed on the second stage beam 68. A furnace bottom brick 70 including a residue is installed via a bottom, and a furnace bottom mantel 71 is installed. The lowermost floor beam 63, the first floor beam 65, the second floor beam 68, and the bottom mantle 71 are referred to as a blast furnace bottom portion 66. Depending on the blast furnace, there is a blast furnace in which the second stage beam 68 is omitted, but in this case, the same method can be applied.

  When constructing the blast furnace bottom 66, first, a lowermost floor beam 63 is first installed in a recess 62 formed on the upper surface of the blast furnace foundation concrete 61, as shown in FIG. 1. The concrete raised in a convex shape between the recesses 62 is referred to as the uppermost foundation concrete layer 61a. The reason why the lowermost floor beam 63 is installed in the concave portion 62 instead of a plane is to ensure the connection between the lowermost floor beam 63 and the blast furnace foundation concrete 61. After the lowermost floor beam 63 is installed in the concave portion 62, the grout 64 is filled in the concave portion 62 so as to fill the gap between the lowermost floor beam 63. Thereafter, the first stage beam 65, the second stage beam 68, the furnace bottom mantel 71, the furnace bottom brick 70, and the like are sequentially installed on the lowermost stage beam 63.

  The base of the blast furnace, which is the object of implementation of the repair method of the present invention, has the above-described configuration. When dismantling the blast furnace bottom 66 for repair of the blast furnace main body, the cutting level 72 is positioned below the bottom beam 63. A plurality of through-holes 77 are opened, a wire saw 45 is passed through the through-holes 77 in the horizontal direction as shown in FIG. 4A, and the foundation concrete 61 and the blast furnace bottom 66 are separated into upper and lower parts, and then temporarily installed. A bracket 73 is newly installed to directly support the first stage beam 65, and a temporary hydraulic jack 74 is used to lift the blast furnace bottom 66 through the installation bracket 73, so that the upper surface of the blast furnace bottom 66 and the blast furnace foundation concrete 61 is cut. A gap 75 in which a lateral movement means such as a roller can be inserted is formed. After that, the support of the blast furnace bottom 66 is transferred from the temporary hydraulic jack 74 to the lateral movement means and moved out of the furnace body rod.

  Normally, the upper surface of the blast furnace foundation concrete 61 is cooled when the blast furnace is in operation, but is exposed to high temperature, the strength of the concrete is reduced, cracking or pulverization occurs. It is fragile. Therefore, as shown in FIG. 3, the first stage beam 65 in the blast furnace bottom 66 located above the horizontally cut level 72 is directly supported by the temporary bracket 73 together with the lowermost stage beam 63 and temporarily installed. When the hydraulic jack 74 is lifted away from the blast furnace foundation concrete 61, the uppermost foundation concrete layer 61a filled between the lowermost floor beams 63 and raised to the same level as the grout 64 is lifted together. .

  The boundary surface 76 between the uppermost foundation concrete layer 61a and the grout 64 is not connected by a reinforcing bar or the like, and the uppermost foundation concrete layer 61a becomes brittle due to the heat of the blast furnace and becomes a small piece 61b or is powdered and peeled off. There is a danger, and these may fill the gaps 75 located below to hinder the smoothness of the cut surface, and may make it impossible to arrange the moving equipment for the blast furnace bottom 66. For this reason, the conventional method has been difficult to apply in practice.

The present invention proposes a blast furnace refurbishing method that solves the above problems. That is, according to the present invention, when the bottom of the blast furnace is lifted away from the blast furnace foundation concrete, the uppermost foundation concrete layer that has become brittle by the heat of the blast furnace is prevented from peeling off, and the concrete pieces 61b and the like may fall into the lower gap 75. Is to eliminate.

  In order to solve the above problems, the present invention is configured as follows.

A first aspect of the present invention is filled with grout as well as installing a bottom insole beam in a recess formed in the top surface concrete layer of the blast furnace foundation concrete, first stage insole beam is placed thereon, and the lowermost A blast furnace bottom including a floor beam, the first stage beam, and a bottom mantel is provided. The bottom of the blast furnace is separated from the blast furnace foundation concrete, and the bottom bottom mantel and the upper mantel are separated from each other. In the blast furnace renovation method that lifts and moves laterally from the installation location,
A plurality of through holes are made in the blast furnace foundation concrete directly under the furnace bottom, and the blast furnace foundation concrete is horizontally cut at the position of the through hole, and the blast furnace bottom and the blast furnace foundation concrete are separated, and the cut gap is used. A high-strength cloth-like sheet (carbon fiber, etc.) was slid on the cut surface, and the end of the high-strength cloth-like sheet was fixed to the bottom floor mantel or the first stage floor beam on the separated blast furnace bottom side . after, by raising a hand-stage lift the blast bottom a gap is formed between the blast bottom and blast concrete foundation, established the moving means in the gap, repair of blast furnace, characterized in that to move the blast furnace bottom Construction method.

  According to the blast furnace refurbishment method of the present invention, a horizontal through hole 77 is made in the uppermost foundation concrete layer 61 a, and the horizontal wire 79 and 46 are horizontally cut using the through hole 77. Using a high-strength cloth sheet (carbon fiber, etc.) 78a in the gap 78 generated during horizontal cutting and fixing it to the furnace bottom mantel 35 or first stage beam 65, it becomes brittle and peels off with high heat. It is possible to prevent the uppermost foundation concrete layer 61a from peeling off. Therefore, the uppermost foundation concrete layer 61a is surely lifted integrally with the bottom of the blast furnace, the concrete piece can be prevented from dropping into the gap, and the cut surface can be smoothed, and the moving means can be smoothly arranged in the gap. . As a result, the blast furnace bottom 66 can be unloaded from the installation position, and the blast furnace bottom 66 can be repaired smoothly and quickly.

  An embodiment of the present invention will be described with reference to FIGS. 1 to 4 have been described with reference to [0017] to [0026], and will be described with reference to FIG.

  In the present invention, as shown in FIG. 5, the foundation concrete 61 is horizontally cut at a cutting level 72 positioned below the lowermost floor beam 63, and a first-stage floor beam 65 positioned above the cutting level 72 is provided. The blast furnace bottom concrete 66 including the first stage beam 65, the second stage beam 68, and the furnace bottom mantel 71 is directly supported by a new temporary bracket 73 and lifted appropriately by a temporary hydraulic jack 74 or the like. As shown in FIG. 4 (a), as shown in FIG. 4 (a), the uppermost foundation concrete layer 61a is lifted together with the blast furnace bottom 66 before being lifted. After penetrating through the through hole 77, a wire saw is inserted into the adjacent through hole 77, and the blast furnace foundation concrete 61 is cut at the position of the horizontal through hole 77. The high-strength cloth-like sheet 78a is installed at the cutting level 72 by using the horizontal pulling wire 79 using the gap 78 generated in the horizontal cutting and the through-hole 77 opened in the horizontal direction. The sheet 78a is fixed to the furnace bottom mantel 35 or the first stage beam 65 and covers at least the lower surface of the uppermost foundation concrete layer 61a. Thereafter, the first stage beam 65 is directly supported by the temporary bracket 73 and is lifted away from the blast furnace foundation concrete 61 by the temporary hydraulic jack 74.

  FIG. 6 shows an example of the lowermost laying beam 63. Elements equivalent to those in FIGS. 1 to 5 are denoted by the same reference numerals and description thereof is omitted.

  As described above, by carrying out the method of the present invention, the top and bottom surfaces of the cut surface of the uppermost foundation concrete layer 61a are smoothed by preventing the concrete pieces of the uppermost foundation concrete layer 61a that have been thermally deteriorated from falling. The moving means can be smoothly arranged in the gap 75 formed in the cut surface material, and the blast furnace bottom 66 can be collectively transported through the moving means, so that the blast furnace base can be repaired. Can be performed smoothly and quickly.

Shown below is the blast furnace foundation where the renovation method described in this explanation is carried out, and the construction of the blast furnace bottom where the bottom laying beam, the first stage laying beam, the second stage laying beam, and the furnace bottom mantel are constructed in this order on the blast furnace foundation concrete It is sectional explanatory drawing in the middle. It is sectional explanatory drawing of the construction completion state of a blast furnace bottom part. It is sectional explanatory drawing which shows the state of the dismantling construction of the conventional blast furnace bottom part as a comparative example. It is an execution outline figure of cutting and exfoliation measures construction of blast furnace foundation concrete concerning an embodiment of the present invention. It is sectional explanatory drawing which shows the state of the dismantling construction of the blast furnace bottom part which concerns on embodiment of this invention. It is a figure which shows the arrangement | positioning aspect of the lowest stage laying beam. It is a front sectional view of a blast furnace body showing a conventional blast furnace bottom repair method. (A) is partial explanatory drawing which shows the dismantling of the blast furnace bottom part of FIG. 7, (b) is a plane explanatory drawing which shows the cutting | disconnection aspect of foundation concrete.

Explanation of symbols

10 Blast Furnace 11 Blast Furnace Foundation Concrete 12 Blast Beam 13 Blast Furnace Main Body 14 Furnace Body 22 Struts 29 Iron Skin 30 Stave Cooler 31 Furnace Brick Layer 33 Remnant 34 Upper Mantel 35 Furnace Bottom Mantel 36 Blast Furnace Bottom 37-40 Cutting Sections 41-44 Boundary 45, 46 Wire saw 49 Horizontal cutting part 50, 51 Center hole jack 52, 53 Suspension bracket 54 Unloading floor 55 Rail member 57 Heavy goods transport cart 58 Cart 61 Blast furnace foundation concrete 61a Uppermost foundation concrete layer 62 Recessed part 63 Bottom stage Laying beam 64 Grout 65 First stage beam 66 Blast furnace bottom 68 Second stage beam 69 Furnace bottom plate 70 Furnace bottom brick 71 Furnace bottom mantel 72 Cutting level 73 Temporary bracket 74 Temporary hydraulic jack 75 Clearance 76 Boundary surface 77 Through hole 78 Flat cutting gap 78a high intensity cloth sheet generated during (carbon fiber)
79 Horizontal wire

Claims (1)

The bottom step beam is installed in the recess formed in the uppermost concrete layer of the blast furnace foundation concrete and filled with grout. The first step beam is installed on the upper part , and the bottom step beam and the first step beam are provided. A blast furnace bottom including a beam and a bottom mantle is provided. The bottom of the blast furnace is separated from the blast furnace foundation concrete, and the bottom mantle and the upper mantel are separated from each other, and then the blast furnace bottom is lifted and laterally moved from the installation place. In the blast furnace refurbishment method,
A plurality of through holes are made in the blast furnace foundation concrete directly under the furnace bottom, and the blast furnace foundation concrete is horizontally cut at the position of the through hole, and the blast furnace bottom and the blast furnace foundation concrete are separated, and the cut gap is used. A high-strength cloth-like sheet is slid on the cutting surface, and the end of the high-strength cloth-like sheet is fixed to the furnace floor mantel or the first stage floor beam on the separated blast furnace bottom side , A blast furnace refurbishment method characterized by forming a gap between a blast furnace bottom and a blast furnace foundation concrete by raising with a lifting means , installing a moving means in the gap, and moving the blast furnace bottom.

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