JP7140270B2 - Staves for cooling blast furnace walls - Google Patents

Description

TECHNICAL FIELD The present invention relates to a furnace wall cooling stave used for cooling and protecting a furnace wall such as a blast furnace exposed to high temperatures.

Conventionally, furnace wall cooling staves (hereinafter also referred to as staves) have been used to protect the blast furnace body from the heat load in the furnace. The stave has a stave body made of cast iron, rolled copper, cast copper, or the like, and the stave body has water channels for cooling. The stave may have a member for attaching the stave to the blast furnace, or a member made of a different type of metal or refractory than the stave body may be attached to the surface of the stave body. The whole unit including the parts is called a stave. In recent years, in order to cope with the high heat load of the blast furnace body, staves with higher cooling capacity and durability have been required.

The reason for this is that coking coal, which is suitable for producing coke, which is the main reducing agent in blast furnaces, is being depleted, and the amount of pulverized coal that is injected from the tuyere of the blast furnace to replace the coke is increasing. is given. This is because if the pulverized coal injection amount is increased, the ventilation resistance in the furnace increases and the air current rising along the furnace wall increases, resulting in an increase in the heat load of the stave and a shortened life.

Such furnace wall cooling staves are fixedly attached to the inside of the blast furnace using furnace shells and bolts. That is, as one example is shown in FIG. 5, the stave body 51 is fixed to the steel shell 61 of the blast furnace body by screwing using bolts 52 and nuts 53 . Then, the water supply and drainage pipes 54-1 and 54-2 of the stave body 51 are provided through holes 62 drilled in the steel shell 61 of the blast furnace body, and the water supply and drainage pipes 54-1 and 54-2 Water is supplied and drained from the outside of the furnace body through the

As a technology to improve furnace wall cooling staves, conventionally, even if the refractory inside the furnace is damaged due to long-term use in places with high heat loads in the blast furnace, the formation of a stable slag adhesion layer generated from the blast furnace contents. It is known to provide the furnace interior of the stave body with a channel-like structure that facilitates the accumulation of blast furnace contents in order to provide thermal insulation and extend life. Further, it is known to provide a groove extending in the direction of the coolant pipe on the surface of the stave body in order to suppress deformation of the stave due to heat (Patent Document 1). Moreover, in order to enhance the effect of protecting the stave, it is known to provide a liner made of a heat-resistant metal material that fits into the horizontal groove of the stave body (Patent Document 2).

JP 2003-269867 A JP-A-2000-119713

However, as in Patent Document 1, when vertical grooves are provided among a plurality of grooves for escaping elongation due to heat received from the furnace and preventing deformation, there is an air current rising along the vertical grooves. As a result, the slag-adhered layer is removed by the airflow, and the slag-adhered layer is not formed in the portion where the vertical groove exists, and the heat input to the stave from that portion increases. Therefore, even if a structure is adopted in which the strain due to heat is absorbed by a vertically penetrating groove, the heat is received from the inner surface of the groove, so the temperature rather rises, and the effect of strain absorption is reduced.

In addition, as in Patent Document 2, even if a liner is provided so that heat is not directly transmitted to the stave inside the furnace of the stave, if the liner surface is smooth, the slag adhesion layer is formed inside the furnace. No, the liner surface is directly exposed to the hot furnace airflow. As a result, the temperature of the liner rises, shortening the life of the liner and limiting the effect of stave protection. In particular, when the liner is fixed with bolts from the inside of the furnace, the bolt temperature becomes higher than the liner temperature, shortening the life of the bolts and shortening the period during which the liner can be fixed.

An object of the present invention is a furnace wall cooling stave used for cooling and protecting a furnace wall such as a blast furnace exposed to high temperatures, wherein the furnace wall cooling stave is provided with a liner inside the furnace, wherein the liner To provide a furnace wall cooling stave of a blast furnace, which can prevent the temperature rise of the liner and prolong the life of the liner.

As a result of intensive research to solve the above-mentioned problems that the conventional technology has and to realize the above-mentioned purpose, the inventors have developed a new stave for cooling the furnace wall of the blast furnace described below. . That is, the present invention is a furnace wall cooling stave that cools the furnace wall of a blast furnace from the inner surface, and includes a stave body made of copper or a copper alloy and a stave body made of copper or a copper alloy, and a stave body inside the furnace inside the stave body. A plurality of horizontal grooves provided horizontally on the surface, the horizontal grooves forming recesses formed by the plurality of horizontal grooves and the protrusions formed between the plurality of horizontal grooves, and the horizontal grooves perpendicular to the protrusions between the horizontal grooves It has a plurality of vertical grooves provided in the direction and a plurality of liners that are fitted in the horizontal grooves of the stave body and whose tips protrude into the furnace, and the vertical gap between the plurality of liners The stave for cooling the furnace wall of a blast furnace, characterized in that the vertical grooves are located at different positions in the horizontal direction.

In addition, in the stave for cooling the furnace wall of the blast furnace according to the present invention configured as described above,
(1) A counterbore hole and a bolt hole penetrating into the counterbore hole are provided from the inside of the furnace of the liner, and a female screw hole is provided at a position corresponding to the bolt hole at the bottom of the horizontal groove of the stave body, the counterbore hole and The liner is fitted into the horizontal groove by inserting a bolt from the inside of the furnace through the bolt hole and fixing the bolt to the female threaded hole;
(2) The vertical width of the concave portion is larger than the vertical width of the convex portion;
(3) The material of the liner is made of a material having higher high-temperature strength than the material of the stave body,
(4) the positions of the gaps between the vertically adjacent liners are different in the horizontal direction;
(5) the vertically adjacent vertical grooves are positioned differently in the horizontal direction;
(6) the positions of the gaps between the vertically adjacent liners are horizontally different, and the vertically adjacent vertical grooves are horizontally different;
is considered to be a more preferable solution.

According to the blast furnace furnace wall cooling stave of the present invention, since the liner protrudes into the furnace, the tip of the protrusion between the horizontal grooves between the liners and the base of the liner (the liner fits into the recess of the stave body A slag adhesion layer with low thermal conductivity is also formed and maintained in the vicinity of the part where the heat is applied. This prevents the temperature of the liner from rising and extends the life of the liner. In addition, the vertical gap between the liners is different from the vertical groove provided on the convex part of the stave body, and the groove is not communicated in the vertical direction, so the airflow rising along the vertical groove is hindered and the slag adhesion layer is maintained, heat reception from the gap between the liners and the inner surface of the vertical groove is prevented, and the life of the liner and stave can be extended.

In addition, according to a preferred embodiment of the present invention, a counterbored hole and a bolt hole penetrating into the counterbore are provided from the inside of the furnace of the liner, and a female screw hole is provided at a position corresponding to the bolt hole at the bottom of the horizontal groove of the stave body. , the counterbored hole and the bolt hole, the bolt is inserted from the inside of the furnace and fixed to the female threaded hole. Therefore, horizontal movement of the position of the liners during use is prevented to prevent the vertical gap between the liners from becoming the position of the vertical groove, and the gap between the liners can be kept constant. In addition, since a slag adhesion layer is formed in the counterbored hole and the stave body is effectively cooled by the liner and the stave body that fits on the top, bottom, and bottom surfaces, the bolt does not wear even after long-term use. .

Furthermore, according to another preferred embodiment of the present invention, by making the positions of the gaps in the horizontal direction between the vertically adjacent liners different, it is possible to prevent the airflow from passing through the gaps between the liners. The life of the liner can be extended by preventing the removal of the slag adhered layer due to the slag and preventing heat reception from the vertical gap between the liners and the inner surface of the vertical groove. Furthermore, according to still another preferred embodiment of the present invention, by making the positions of vertically adjacent vertical grooves different, it is possible to prevent airflow from penetrating through the vertical grooves, thereby preventing the slag adhesion layer from being damaged by the airflow. Expulsion can be prevented, heat reception from the inner surface of the vertical groove can be prevented, and the life of the stave can be extended. In addition, when the positions of the vertical gaps between the adjacent liners are different and the positions of the vertically adjacent vertical grooves are different, the effect of extending the life of the stave can be further improved.

It is the figure which looked at an example of the stave for furnace wall cooling of the blast furnace of the present invention from the furnace inside. FIG. 2 is a cross-sectional view along line AA of the furnace wall cooling stave of the blast furnace of the present invention shown in FIG. Fig. 2 is a view of an example of a stave before a liner is attached in the furnace wall cooling stave of the blast furnace of the present invention, as seen from the inside of the furnace. FIG. 4 is a cross-sectional view along line AA of the stave prior to attachment of the liner shown in FIG. 3; It is a figure for demonstrating the method of fixing the stave for furnace wall cooling in a conventional example to a furnace body shell.

Hereinafter, the stave for cooling the furnace wall of the blast furnace of the present invention will be described.
The stave for cooling the furnace wall of the blast furnace of the present invention: a stave body made of copper or a copper alloy and having a water channel for passing cooling water inside; and a plurality of staves extending horizontally on the furnace inner surface of the stave body. the horizontal grooves forming recesses formed by a plurality of horizontal grooves and protrusions formed between the plurality of horizontal grooves; extending vertically to the protrusions between the horizontal grooves; a plurality of vertical grooves; and a plurality of liners that are fitted in the horizontal grooves of the stave body and whose tips protrude into the furnace; and extend vertically between the plurality of liners. The gaps are configured to be at different positions in the horizontal direction than the vertical grooves, ie, the vertically extending gaps between the liners do not communicate with the vertical grooves.

The state that the gap does not communicate with the groove means that either or both of the upper end and the lower end of the groove are closed by the liner in the vertical direction, and the space that constitutes the groove is open only in the direction of the inner surface of the furnace. point to In the present invention, it is preferable that 70% or more of the upper and lower ends of the grooves present in the stave body are closed. It is more preferable that 90% or more of the upper and lower ends of the groove are closed by the liner, and it is most preferable that the groove is closed at all positions.

In the stave that cools the furnace wall of the blast furnace from the inside by blowing high temperature air from the bottom of the blast furnace and extracting the generated gas from the top, when the speed of the upward gas flow along the stave surface increases, the inner surface of the stave The heat transfer coefficient of increases, and the temperature of the stave tends to rise. In the stave for cooling the furnace wall of the blast furnace of the present invention having the above-described configuration, the stave is made of copper or a copper alloy with high thermal conductivity, so the furnace inner slag is cooled on the furnace inner surface of the stave to form an adhesion layer. . Thereby, the stave itself can be protected for a long period of time. Further, in the stave for cooling the furnace wall of the blast furnace of the present invention, the stave is cooled by flowing water through the cooling water passage provided in the stave body.

A plurality of horizontal grooves are provided horizontally on the furnace inner surface of the stave body. A plurality of horizontal grooves constitute recesses, and a projection is formed between the plurality of horizontal grooves or between the horizontal grooves and the upper or lower end of the stave body. The horizontal groove of the stave body is provided with a liner that is fitted to the top and bottom surfaces of the stave body and whose tip protrudes into the furnace. It is preferable that the liner material has higher hardness and high-temperature strength and lower thermal conductivity than the stave material. Therefore, even if the temperature rises more than the stave main body, it can withstand, and the heat transmitted to the stave main body can be reduced. Since the liners protrude into the furnace, a slag adhered layer with low thermal conductivity is formed and maintained at the tops of the protrusions between the horizontal grooves between the liners and also at the bases of the liners. The base portion where the liner is fitted with the horizontal groove of the stave is cooled by the stave and kept at a low temperature, but the tip portion protruding into the furnace receives the heat in the furnace and becomes high temperature.

A groove is provided in the convex portion adjacent to the horizontal groove of the stave body so as to intersect with the extending direction of the convex portion. This groove has openings connected to horizontal grooves or stave ends present at the upper end and the lower end of the projection, and is provided so as to connect the openings. In the present invention, the groove provided in the projection is referred to as a vertical groove, but it is not limited to the direction at 90° to the extending direction of the projection. Due to the presence of this groove, deformation due to thermal stress generated in the stave body due to temperature change can be alleviated. The width of the vertical groove is preferably 1 mm or more and 50 mm or less. More preferably, it is 8 mm or more and 30 mm or less. The depth of the vertical grooves can be the same as the horizontal grooves, but shallower grooves are also effective. It is preferable that the groove has a depth of 1/2 or more of the projection height of the projection (the distance between the top end of the projection and the bottom surface of the groove). A more preferable depth of the groove is about 3/4 to 1 times the height of the projection. Further, it is preferable that the vertical grooves provided in the convex portion are provided at intervals of 100 mm to 500 mm in the horizontal direction. Further, it is more preferable that the vertical grooves are provided at intervals of 150 mm to 300 mm in accordance with the pitch of the cooling water passages.

The liner fitted in each horizontal groove is divided into a plurality of pieces, and the vertical gaps between the liners absorb thermal expansion. If the gap between the liners is at the same vertical position as the vertical grooves in the stave body, the gap and vertical groove will penetrate and the airflow will pass through. Therefore, the slag adhesion layer is removed by the air flow, and heat is received from the gap between the liners and the inner surface of the vertical groove, so the temperature rises. However, by making the positions of the gaps between the liners and the positions of the vertical grooves different in the horizontal direction, it is possible to prevent airflow from passing through and effectively absorb thermal expansion.

Next, preferred examples of the furnace wall cooling stave of the blast furnace of the present invention will be described.
First, if the liner is only fitted in the horizontal groove of the stave body, the position of the vertical gap between the liners will become the position of the vertical groove due to the horizontal movement of the liner during use. There is In order to prevent this and keep the gap between the liners constant, a countersunk hole is made inside the furnace of the liner, a bolt hole is made at the bottom of the countersunk hole, a bolt is passed through the bolt hole, and the stave body is The horizontal movement of the liner can be prevented by fixing it to the threaded hole provided in the horizontal groove. The bolt itself is cooled by the internal thread hole of the stave body, and a slag adhesion layer with low thermal conductivity is formed in the countersunk hole, so the temperature rise of the bolt can be avoided. Furthermore, the counterbored holes in the liner are deeper outside the furnace than the tip of the protrusion between the horizontal grooves of the stave, and the bolts are positioned on the liner and the stave body, which is fitted on the top, bottom, and bottom surfaces, for effective cooling. Therefore, the temperature rise of the bolt can be avoided, and the bolt will not wear even after long-term use. According to the liner fixing method of the present invention, it is possible to effectively prevent the liner from coming off or being damaged, and to greatly extend the life of the liner, as compared with the conventional liner fixing method. As a result, the life of the stave can also be significantly extended.

Next, it is preferable that the vertical width of the concave portion of the stave body is larger than the vertical width of the convex portion. With this configuration, the protrusions between the horizontal grooves directly receive the heat in the furnace and become higher in temperature than the horizontal grooves. be able to. In addition, since the liner protrudes into the furnace from the tip of the projection between the horizontal grooves of the stave, a slag adhesion layer with low thermal conductivity is formed in the gap between the vertically adjacent liners.

Moreover, it is preferable that the liner is made of a material having higher high-temperature strength than the material of the stave main body. Stainless steel, SS steel, etc. can be used suitably as an example of the material of a liner with high temperature strength higher than the stave main body which consists of copper or copper alloys.

Furthermore, by making the gaps between the vertically adjacent liners different in the horizontal direction, it is possible to prevent air currents from penetrating through the gaps between the liners, thereby preventing the removal of the slag adhered layer due to the air currents. It is possible to prevent heat reception from the gap between the liners and the inner surface of the vertical groove. It is preferable that the gap between the liners is 5 mm or more and 500 mm or less. Varying the horizontal position of the gap between liners means arranging the liners so that the protrusion of the adjacent liner is located directly above and/or directly below the gap between liners at a given height. is. Therefore, it is preferable that the gap provided between the liners is shorter than the length of the liners arranged in the groove. In 70% or more of the gaps between the liners, it is preferable that the gaps are different in horizontal position from the gaps of the vertically adjacent liners.

In addition, when the liner wears out or falls off due to long-term use, a slag adhesion layer with low thermal conductivity is formed in the horizontal groove of the stave body. In that case, by differentiating the horizontal position of the vertically adjacent vertical grooves, it is possible to prevent the vertical grooves from penetrating and the airflow to pass through, thereby preventing the removal of the slag adhered layer due to the airflow and the inner surface of the vertical grooves. It is possible to prevent heat reception from.

The horizontal position of the vertically adjacent vertical grooves is different, and the stave body convex portion adjacent to the opening of the vertical groove in the stave body convex portion at a certain height is located directly above and / or directly below the opening. is to arrange the vertical grooves so that Even in this case, it is preferable that the horizontal position of 70% or more of the vertical grooves is different from the position of the vertical grooves of adjacent protrusions.

By providing both the above-described different horizontal positions of the gaps between the vertically adjacent liners and the above-described different horizontal positions of the vertically adjacent vertical grooves, the slag Prevention of removal of the sticking layer can be more effectively achieved.

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a view of an example of the blast furnace wall cooling stave of the present invention as viewed from the inside of the furnace, and FIG. 2 is a view of the blast furnace wall cooling stave of the present invention shown in FIG. 1 is a cross-sectional view along FIG. Hereinafter, with reference to FIG. 1 and FIG. 2, the structure of the furnace wall cooling stave of the blast furnace of the present invention will be described.

In the example shown in FIGS. 1 and 2, a large number of stave bodies 1 are arranged in the circumferential direction of the blast furnace, and oxygen-free copper is used as an example of the material. A plurality of liners 2 are fitted into the horizontal groove 13 dug in the stave body 1 by cutting with a gap 5 in the vertical direction (vertical direction in the figure) between the liners 2, and the hexagon socket head bolt 3 has been concluded by An example of the dimensions of the horizontal groove 13 is a deep trapezoidal shape with a depth 13a of 55 mm, a vertical width of 75 mm at the bottom 13b, and a width of 70 mm at the opening 13c. Therefore, the liner 2 fitted in the horizontal groove 13 will not come off. Further, since the liner 2 is fitted in the horizontal groove 13 and then fixed in the horizontal direction by the bolt 3, the width of the vertical gap 5 between the liners 2 does not change due to external force. can be maintained.

A concave portion 21 is formed by the horizontal grooves 13 , and a convex portion 22 is formed between the upper and lower horizontal grooves 13 . In this example, a plurality of vertical grooves 4 having a width of 10 mm and a depth of 55 mm are formed by cutting in the formed convex portion 22, for example. Each of the plurality of vertical grooves 4 is arranged at a position offset in the horizontal direction from the vertical gap 5 between the liners 2 . Therefore, the slag adhered layer formed on the inner surface of the furnace is maintained on the liner 2 without the vertically rising air current passing through the blast furnace.

In the present invention, the horizontal position of the vertical gap 5 between the vertically adjacent liners 2 and the horizontal position of the vertically adjacent vertical grooves 4 are not particularly limited. However, as a preferred example, as shown in FIGS. 1 and 2, it is preferable to configure the vertical gaps 5 between the vertically adjacent liners 2 so that their positions are different in the horizontal direction. When the vertical gap 5 of the liner 2 is configured in this way, it is possible to more preferably prevent the vertically rising airflow from passing through when the liner 2 exists. As a preferred example, as shown in FIGS. 1 and 2, it is preferable to configure the vertical grooves 4 adjacent to each other vertically at different horizontal positions. When the vertical grooves 4 are constructed in this manner, even if the liner 2 wears out or falls off due to long-term use, the upper and lower vertical grooves 4 are horizontally displaced from each other, so that the air currents rising vertically are prevented. The slag adhered layer formed on the inner surface of the furnace is maintained.

FIG. 2 is a cross-sectional view along line AA of the furnace wall cooling stave of the blast furnace of the present invention shown in FIG. In the example shown in FIG. 2, a horizontal groove 13 with a wider bottom is dug in the stave body 1, which is a plate of a copper wrought product with a predetermined thickness. A cooling water passage 6 arranged in the vertical direction of the stave is drilled upward from the lower end surface of the plate by a gun drill and stopped without penetrating. In that state, the cooling water passage 6 has a water supply port 7 and a water discharge port 8 with the same diameter as the cooling water passage 6 from the back surface of the stave that hits the outside of the furnace. A water supply pipe 9 penetrates the shell of the blast furnace to the water supply port 7 and supplies cooling water from outside the furnace, and a drain pipe 10 penetrates the shell of the blast furnace and discharges the cooling water to the outside of the furnace. are attached to the stave body 1 by fillet welding. The hole below the cooling water passage 6 is sealed by V-groove welding a plug 11 .

The liner 2 is horizontally inserted along a horizontal groove 13 dug in the stave body 1 and fastened with a bolt 3 at a predetermined position. Since the bolt 3 is located at the bottom of the counterbored hole 12, it is tightened with a hexagon wrench using a hexagon socket bolt. In the furnace, a slag adhesion layer is also formed in the counterbore 12, so that the head of the bolt 3 can be protected. The counterbore 12 is deeper than the tip of the protrusion 22 between the horizontal grooves 13 so that the temperature of the bolt 3 does not rise.

FIG. 3 is a view of an example of the stave before the liner is attached in the stave for cooling the furnace wall of the blast furnace of the present invention, as seen from the inside of the furnace, and FIG. - It is sectional drawing along A line. In the example shown in FIGS. 3 and 4, the stave body 1 is milled with horizontal grooves 13 . At the bottom of the horizontal groove 13, an internal screw hole 14 for bolting the liner 2 with the bolt 3 is tapped. The female threaded hole 14 is provided at a position away from the cooling water passage 6 in the horizontal direction so as not to penetrate the cooling water passage 6 . After cutting and welding are finished, a plurality of liners 2 to be fitted into the horizontal grooves 13 are sequentially inserted from the side. When the centers of the female threaded hole 14 and the bolt hole 23 concentric with the counterbored hole 12 are aligned, the bolt 3 is tightened to stop sliding along the horizontal groove 13. - 特許庁

The stave for cooling the furnace wall of the blast furnace according to the present invention is particularly effective as a stave for cooling the furnace wall of the blast furnace from the inner surface by blowing high-temperature air from the lower part of the furnace and taking out the generated gas from the upper part. Shaft furnaces other than blast furnaces It is also effective for cooling and protecting the inside of the furnace wall exposed to high temperatures.

1 Stave Body 2 Liner 3 Hex Socket Head Bolt 4 Vertical Groove 5 Gap 6 Cooling Water Passage 7 Water Supply Port 8 Drainage Port 10 Drainage Pipe 11 Plug 12 Countersunk Hole 13 Horizontal Groove 13a Depth 13b Bottom 13c Opening 14 Female Screw Hole 21 Recess 22 Protrusion 23 Bolt hole

Claims (7)

A furnace wall cooling stave for cooling the furnace wall of a blast furnace from the inside,
A stave body made of copper or a copper alloy and provided with a water channel for passing cooling water inside,
A plurality of horizontal grooves provided horizontally on the furnace inner surface of the stave body, the horizontal grooves forming recesses formed of a plurality of horizontal grooves and protrusions formed between the plurality of horizontal grooves;
a plurality of vertical grooves provided in the vertical direction on the convex portion between the horizontal grooves;
A plurality of liners that are fitted into the horizontal grooves of the stave body and whose tips protrude into the furnace,
A stave for cooling the furnace wall of a blast furnace, characterized in that there is a vertical gap between a plurality of liners at a position where either or both of the upper end and the lower end of the vertical groove are vertically closed by the liner. A counterbore hole and a bolt hole penetrating into the counterbore hole are provided from the inside of the furnace of the liner, and a female screw hole is provided at a position corresponding to the bolt hole at the bottom of the horizontal groove of the stave body, and the counterbore hole and the bolt hole are provided. 2. The liner is fitted in the horizontal groove by inserting a bolt from the inside of the furnace through and fixing the bolt to the female threaded hole, according to claim 1 A stave for cooling the wall of a blast furnace. The stave for cooling the furnace wall of a blast furnace according to claim 1 or 2, wherein the vertical width of the concave portion is larger than the vertical width of the convex portion. The stave for cooling the furnace wall of a blast furnace according to any one of claims 1 to 3, characterized in that the material of the liner is made of a material having higher high-temperature strength than the material of the stave body. The stave for cooling the furnace wall of a blast furnace according to any one of claims 1 to 4, characterized in that the gaps between the vertically adjacent liners are horizontally different. The stave for cooling the furnace wall of a blast furnace according to any one of claims 1 to 4, characterized in that the vertically adjacent vertical grooves are different in position in the horizontal direction. 5. The method according to any one of claims 1 to 4, characterized in that the gaps between the vertically adjacent liners have different positions in the horizontal direction, and the vertically adjacent vertical grooves have different positions in the horizontal direction. A stave for cooling the furnace wall of the blast furnace described.

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