JP2009167507A - Runner-receiving beam for molten iron runner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a runner-receiving beam with which the deformation of a runner and the generation of crack or gap in a molten iron runner can be prevented, when the expansion or the shrinkage is developed by varying the temperature of a runner iron shell of the molten iron runner. <P>SOLUTION: In the runner-receiving beam 15 for supporting by laying the molten iron runner as the flowing passage of the molten iron discharged from a blast furnace, the upper surface of a shape steel 16 assembled as the lattice-state so as to constitute the runner-receiving beam 15, is formed as the flat plane so as to slide the molten iron runner without restricting with the upper surface of the runner-receiving beam 15 and further, on the upper surface of the above shape steel 16, a liner 17 having higher hardness in comparison with the runner iron shell of the molten iron runner, is fitted. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  TECHNICAL FIELD The present invention relates to a hot metal receiving beam that supports hot metal serving as a flow path for hot metal discharged from a blast furnace.

  As shown in FIG. 5, the hot metal discharged from the blast furnace and the hot metal that forms the flow path of the hot metal are one set of main iron, hot metal, and noro iron, and a plurality of sets are arranged for one blast furnace. . In the operation of the blast furnace 1, the hot metal and hot metal discharged from the blast furnace flow down the main metal 2, and the hot metal and hot metal are separated by the skinmer 5. The separated hot metal flows into the hot metal 4, while the hot metal flows into the hot metal 3.

  A cross-sectional view of the hot metal 3 taken along the line AA is shown in FIG. The hot metal 3 is arranged with refractories 6a, 6b, 6c (hereinafter referred to as permanent tension materials) called permanent tension outside the refractory material 7 (hereinafter referred to as metal plating) that forms the flow path of the molten metal, and these These refractories are reinforced by the side plate 8 and the side section steel 10 and the bottom plate 9 and the bottom section steel 11. Hereinafter, the side plate 8, the side section steel 10, the bottom plate 9, and the bottom section steel 11 are collectively referred to as pig iron skin.

  When the hot metal flows, the hot metal 3 is heated by the retained heat of the hot metal (about 1500 ° C.), and the temperature of the side plate 8 and the bottom plate 9 reaches 200 to 300 ° C. Since the length of the hot metal 3 is about 10 to 25 m, the iron skin will expand about 40 to 100 mm. However, when the hot metal 3 is installed on the casting floor, it is fixed so as to absorb the dimensional change in consideration of such expansion, so there is no particular problem in normal operation.

  However, it sometimes occurs that the temperature of the molten iron skin becomes extremely high due to abnormal rise in the temperature of the hot metal or abnormal wear of the brazing material 7 or the permanent upholstery material 8. In such a case, the pig iron skin expands significantly, while the pig iron skin is restrained by the fixing tool for installing the hot metal 3, so that the pig iron skin undergoes creep deformation. As a result, cracks and gaps are generated in the pig iron skin, the brazing material 7 and the permanent upholstery material 8, which may cause problems such as leakage.

Moreover, when the outflow of hot metal from the blast furnace stops, the pig iron skin is cooled and contracts. In particular, when repairing the brazing material 7 or the permanent upholstery material 8, the shrinkage amount of the pig iron skin becomes the largest because it is cooled to room temperature. If the pig iron skin contracts, the possibility of cracks and gaps occurring in the pig iron skin, the brazing material 7 and the permanent upholstery material 8 increases.
Such a heating-cooling thermal cycle is repeated 3 to 5 times a day (about 500 times a year). For this reason, various techniques for preventing the occurrence of cracks and gaps due to expansion and contraction of pig iron skin have been studied.

Patent Document 1 discloses a technique for repairing cracks and gaps generated in the brazing material 7 and the permanent upholstery material 8 with a refractory material called a stamp material. This technique repairs after the occurrence of a crack or gap, and cannot prevent the occurrence of a crack or gap.
Patent Document 2 discloses a technique for suppressing expansion of pig iron skin by providing a stopper on the saddle receiving beam. In this technique, since a stopper is provided at a position that can absorb a dimensional change of a general pig iron skin, it is not restrained even if the pig iron skin expands in a normal operation, and the occurrence of creep deformation can be prevented. However, it is difficult to set the position of the stopper in consideration of the abnormal rise in pig iron skin temperature. When an abnormal rise in pig iron skin temperature occurs, the pig iron skin expands significantly, the stopper comes into contact with the saddle receiving beam, and the pig iron skin is restrained, so that creep deformation is inevitable. Therefore, it is impossible to prevent cracks and gaps from occurring in the hot metal.

Patent Document 3 discloses a technique for fixing the hot metal to the iron receiving beam while providing slits in the side shape steel and bottom shape steel of the pig iron skin to absorb the expansion and contraction of the pig iron skin. It is disclosed. That is, the expansion amount is absorbed by the narrowing of the slit width with respect to the expansion of the pig iron skin, and the contraction amount is absorbed by the widening of the slit width with respect to the contraction of the pig iron skin. Therefore, it is effective for preventing cracks and gaps in the hot metal due to expansion and contraction in the width direction of the slit, but the effect cannot be obtained in the longitudinal direction of the slit.
JP 2005-232552 JP Japanese Patent Laid-Open No. 2003-293017 Japanese Patent No. 3709172

  The present invention provides a saddle receiving beam that can prevent deformation of a pig iron skin when the pig iron skin of the hot metal expands or contracts due to a change in temperature, and prevents cracks and gaps from occurring in the hot metal. The purpose is to provide.

The present invention is a steel receiving beam for placing and supporting a hot metal serving as a flow path for the hot metal discharged from the blast furnace, and the upper surface of the shape steel assembled in a lattice shape constituting the steel receiving beam is A scissor receiving beam that forms a flat surface so that the scissors are slidably mounted.
In the saddle receiving beam of the present invention, it is preferable that a liner having a higher hardness than that of the molten iron bark is attached to the upper surface of the shape steel.

  According to the present invention, since the hot metal is not constrained, deformation when the pig iron skin expands or contracts due to a change in temperature can be prevented, and cracks or gaps can be prevented from being generated in the hot metal.

FIG. 1 is a cross-sectional view schematically showing an example in which the dredge receiving beam of the present invention is installed on a casting floor of a blast furnace. The eaves receiving beam 15 is constructed by welding shaped steel 16 in a lattice shape, and is fixed on the foundation beam 12 fixed to the floor surface with a bolt 14 via a bracket 13. The bracket 13 is for adjusting the height of the eaves receiving beam 15.
The shape steel 16 constituting the iron receiving beam 15 has a flat upper surface, and no member for restraining the hot metal 3 to be placed is disposed.

The method for placing the hot metal on the iron receiving beam 15 is not limited to a specific procedure, but an example thereof will be described below.
As shown in FIG. 2, a pig iron skin composed of a side plate 8, a side section steel 10, a bottom plate 9 and a bottom section steel 11 is placed on the top surface of the saddle receiving beam 15. In addition, FIG. 3 shows a cross-sectional view taken along arrow BB in FIG. The eaves receiving beam 15 is fixed to the floor surface, but no member for restraining the eaves iron skin is provided on the upper surface of the eaves receiving beam 15. Accordingly, when the pig iron skin expands or contracts as described later, the pig iron skin slides on the saddle receiving beam 15. At that time, the surface indicated by the arrow C in FIGS.

Next, as shown in FIG. 4, the permanent upholstery materials 6a, 6b, 6c and the brazing material 7 are applied, and dehydration and drying are further performed.
In this way, the hot metal 3 and the hot metal receiving beam 15 are used for the operation of the blast furnace 1. If expansion or contraction of the pig iron skin occurs during operation, the hot metal 3 slides on the iron receiving beam 15 without being constrained. Since the weight of the hot metal 3 having a length of about 25 m is about 150 tons, a sufficient frictional force is generated on the hot metal receiving beam 15 and there is no possibility that the hot metal 3 falls off from the hot metal receiving beam 15. According to the study by the inventors, the moving distance generated in one thermal cycle is within 50 mm, and after the hot metal 3 moves by expansion, it returns to its original position by contraction.

If the hot metal 3 does not slide smoothly on the saddle receiving beam 15, a liner 17 may be mounted on the upper surface of the saddle receiving beam 15, as shown in FIG. It is preferable to use a liner 17 having a higher hardness than the pig iron skin of the hot metal 3.
As described above, when the hot metal is placed on the iron receiving beam of the present invention, even if the hot metal expands or contracts, the hot metal slides without being restrained, thereby preventing deformation of the pig iron skin. it can. As a result, it is possible to prevent cracks and gaps from occurring in the hot metal.

  When the hot metal was renewed, the hot metal receiving beam of the present invention shown in FIG. 1 was produced and installed on the casting bed of the blast furnace. The structural steel 16 and the bracket 13 constituting the heel support beam 15 were made of SS400, a general structural rolled steel (JIS standard G3101). A hot rolled stainless steel plate (JIS standard G4304) SUS304N2 (ie, austenitic stainless steel) was mounted on the upper surface of the saddle receiving beam 15 as a liner 17. The hardness of SUS304N2 is HB248, which is 2 to 2.5 times that of SS400. The total amount of these steel materials used was 45 tons.

Next, as shown in FIG. 4, a hot metal 3 having a width of 2 m, a height of 2 m, and a length of 22 m was placed. The total amount of refractories used for the hot metal 3 (ie, the brazing material 7 and the permanent upholstery materials 6a, 6b, 6c) was 135 tons.
The hot metal was poured into the hot metal 3 3 to 4 times per day, and the heat-cooling heat cycle was repeated for 25 days. After that, the hot metal 3 was cooled to room temperature, and the brazing material 7 and the permanent upholstery materials 6a, 6b, 6c were repaired and subjected to normal operation. This is an invention example.

Other hot metal to be placed in the blast furnace was used for operation as conventionally fixed with a stopper. This is a conventional example.
In this way, after the operation of the blast furnace was continued for one year, it was cooled to room temperature and investigated for deformation of the pig iron skin. As a result, in the hot metal placed on the hot metal receiving beam of the inventive example, creep deformation of the pig iron skin was not observed, and the maximum deviation from the position placed when the hot metal was updated was 10 mm. On the other hand, in the conventional example, creep deformation of the pig iron skin was observed.

Further, in the inventive examples, no coarse galling was observed on the upper surface of the liner. This indicates that the hot metal slid smoothly on the liner.
As described above, it was confirmed that the dredge receiving beam of the present invention and the hot metal placed on the upper surface thereof were stably used for the operation of the blast furnace.

It is sectional drawing which shows typically the example which installed the gutter receiving beam of this invention on the foundation. It is sectional drawing which shows typically the example which mounted the pig iron skin on the collar receiving beam of this invention. It is sectional drawing of the BB arrow in FIG. It is sectional drawing which shows typically the example which constructed the permanent tension material and the brazing material 7 to the pig iron skin of FIG. It is a top view of the cast floor which shows the example of arrangement | positioning of a blast furnace and a firewood typically. It is sectional drawing of the hot metal shown in FIG. 5 by the AA arrow.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blast furnace 2 Main iron 3 Hot metal 4 Noro iron 5 Skinmer
6a Permanent upholstery
6b Permanent upholstery
6c Permanent upholstery 7 Fence 8 Side plate 9 Bottom plate
10 Side section
11 Bottom section
12 Foundation beam
13 Bracket
14 volts
15 樋
16 section steel
17 liner

Claims (2)

  A hot metal receiving beam that supports and supports hot metal that becomes a flow path of hot metal discharged from the blast furnace, and an upper surface of the steel frame that is assembled in a lattice shape that constitutes the hot metal receiving beam, A gutter receiving beam comprising a flat surface so as to be slidably mounted. 2. The saddle receiving beam according to claim 1, wherein a liner having a higher hardness than that of the hot metal shell of the hot metal is attached to an upper surface of the shape steel.

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