JP2009263738A - Facility for cooling furnace body of blast furnace - Google Patents

Abstract

[PROBLEMS] To provide a blast furnace furnace cooling facility that can not only effectively cool the furnace body, particularly the side wall of the furnace bottom, but also facilitate the construction and management of the cooling equipment for the entire furnace body without deteriorating the working environment. provide.
The cooling equipment for the furnace wall above the bosch part of the blast furnace furnace body is constituted by a stave cooler, and the cooling equipment for the bottom wall part of the furnace bottom is provided between the furnace wall refractory brick and the iron shell. A facility comprising a plurality of steel cooling pipes arranged in parallel and an irregular refractory material surrounding the steel cooling pipes, and constituting a cooling water circulation system with the stave cooler.
[Selection] Figure 1

Description

  The present invention relates to a furnace body cooling facility for a blast furnace, and in particular, provides a blast furnace furnace cooling facility characterized by a cooling facility for a furnace bottom side wall.

  Conventionally, cooling of the upper part of the furnace from the shaft part to the tuyere of the blast furnace has been mainly performed by a cast iron stave cooler, and in some cases, this cast iron stave cooler and copper stave cooler are used in combination. Cooling techniques have been adopted. And about the furnace bottom side wall part, it was common to water and spray the outer surface of an iron shell. However, in the cooling by watering, mist was generated due to watering, which caused corrosion of floor materials and beam materials of the work floor provided at the blast furnace casting floor and tuyere level. For this reason, there has been a problem that the flooring has to be reinforced even during the operation of the blast furnace, or that the work such as full replacement of the cast floor or work floor is required at the time of repair. In addition, this sprinkling cooling to the bottom wall of the furnace bottom requires a regular inspection because it causes local high temperatures due to local wear of the bottom furnace bricks. There was also a problem that the work was in a poor condition.

In recent years, a technique has been proposed in which a stave cooler is provided also on the side wall of the furnace bottom to prevent the work environment from being deteriorated due to watering. In patent document 1, the method of employ | adopting a cast iron stave cooler in the furnace bottom side wall part, and patent document 2 is employ | adopting the copper stave cooler.
JP 56-96005 A JP-A-9-157716

  However, in the case of the method described in Patent Document 1, that is, the equipment for cooling the furnace bottom side wall portion by disposing a cast iron stave cooler, there are the following problems. In the cast iron stave cooler, an iron pipe is cast into a cast iron disk-shaped stave body, and therefore a non-welded portion exists between the cast tube and the stave body. From this, the cast iron stave cooler has such a problem that the non-welded part becomes a heat insulating layer and the cooling effect rate is lowered, thereby causing the temperature rise of the furnace bottom side wall part and deteriorating the life of the furnace bottom side wall brick. was there.

  On the other hand, the method as described in Patent Document 2, that is, the cooling method using a copper stave cooler in which a cooling water passage is formed in a copper plate, does not have a heat insulating layer like a cast iron stave cooler, The cooling effect is equivalent to that of cooling, the life of the furnace bottom brick is long, and the working environment near the furnace bottom is good.

  However, adopting a copper stave cooler to cool the bottom wall of the furnace bottom may cause an increase in equipment costs due to the recent increase in the price of copper materials. Moreover, this copper stave cooler has a blast furnace furnace body made of steel plate, so when installing it, welding work between different types of copper-steel metal is necessary, welding failure is likely to occur, rework and cooling There was a problem of water leakage.

  Accordingly, an object of the present invention is not only to effectively cool the furnace body, particularly the side wall of the furnace bottom, but also to facilitate the construction and management of the cooling equipment for the entire furnace body, without deteriorating the working environment. It is to provide a furnace body cooling facility.

As a result of diligent research on a method that can realize the above-mentioned object reliably with few obstacles due to the above-described problems of the prior art, the inventors have come up with a solution means relating to the gist configuration described below.
That is, according to the present invention, the cooling equipment for the furnace wall above the bosch part in the blast furnace furnace body is configured by a stave cooler, and the cooling equipment for the furnace bottom side wall part is composed of a furnace wall refractory brick and an iron shell. It is composed of a plurality of steel cooling pipes arranged in between, and an irregular refractory material filled around these steel cooling pipes, and these steel cooling pipes are arranged outside the iron skin. The connecting coolers are connected to each other by the arranged connecting pipe, and the stave cooler arranged in the zone above the Bosch part is also connected by the connecting pipe arranged outside the iron skin, and the steel cooling The pipe is a blast furnace furnace cooling facility characterized in that the pipe constitutes the stave cooler and a cooling water circulation system.

In the configuration of the blast furnace furnace cooling equipment of the present invention,
a. The furnace wall above the Bosch part comprises a shaft part, a belly part and a Bosch part, b. The cooling equipment in the upper part and middle part of the shaft part is a cast iron stave cooler,
c. The cooling equipment for the lower part of the shaft, the belly part and the Bosch part consists of a cast iron stave cooler, or a combination of a cast iron stave cooler and a copper stave cooler or a steel stave cooler,
d. The steel cooling pipe on the side wall of the furnace bottom is formed by arranging a plurality of pipes extending in the furnace height direction in an annular shape in the furnace circumferential direction,
e. The furnace bottom side wall cooling facility has a membrane structure in which a heat transfer plate is fixed between adjacent steel cooling pipes,
f. The amorphous refractory material is a stamp material or a casting material having a thermal conductivity of 10 w / m · K or more;
g. The cast iron stave cooler is formed by casting a cooling pipe in a cast iron disk-shaped stave body,
h. The copper stave cooler and the steel stave cooler have a cooling water passage in a copper rectangular body or a steel rectangular body,
Is a more preferable solution.

By adopting the above solution, the following effects can be expected in the present invention.
(1) According to the present invention, since there is no scattering of cooling water as compared with the conventional technique in which the bottom wall of the furnace bottom is sprinkled and cooled, corrosion of the cast floor and work floor around the furnace body can be suppressed, and the furnace Work such as iron skin inspection for local temperature rise of the bottom side wall becomes easy. Therefore, in the conventional blast furnace refurbishment, the cast floor and work floor around the furnace body were renewed at every refurbishment, but according to the present invention, this renewal work becomes unnecessary and the blast furnace refurbishment work can be shortened. .

(2) According to the present invention, at least for the cooling facility of the bottom wall of the furnace bottom, there is no welding work between different metals such as copper-steel like a copper stave cooler, and everything is welded between steel. This makes it possible to construct a furnace body cooling facility that is easy and reliable.

(3) According to the present invention, unlike a steel or steel stave cooler having a welded portion inside the furnace that cannot be repaired during operation, in the case of a steel cooling pipe, there is no welded portion inside the furnace, Since all the welds are outside the furnace that can be repaired, a highly reliable furnace body cooling facility is provided.

(4) According to the present invention, at least for the cooling facility of the bottom wall of the furnace bottom, the steel cooling pipe can be welded and fixed in advance to a ring-shaped block iron skin forming the furnace bottom at the factory. As a result, most of the cooling facilities can be prepared in the factory, and installation work at the site as in the past is reduced, and the field work can be reduced.

(5) According to the present invention, the cost can be greatly reduced as compared with the use of a copper stave cooler.

(6) According to the present invention, the entire furnace body is cooled by connecting and connecting various stave coolers at the top of the shaft to the steel cooling pipe at the bottom wall of the furnace so as to form a series of cooling water circulation systems. The construction and management of facilities can be unified and performed easily and efficiently.
In recent years, there is also a method in which the cooling water circulation system is divided into two parts, the upper cooling water circulation system and the lower cooling water circulation system, and the cooling is performed according to the present invention. In addition, since a series of cooling water circulation systems can be made from various stave coolers that form the lower cooling water circulation system to the steel cooling pipes on the bottom wall of the furnace bottom, the construction and management of the cooling facilities can be performed simply and efficiently as described above. Can be done well.

  FIG. 1 shows the overall configuration of a blast furnace furnace cooling facility. As shown in this figure, the blast furnace cooling system is composed of a cast iron stave cooler 1 or a cast iron stave cooler 1 and a copper stave cooler 2 or a steel stave cooler 3 from the top of the shaft to the bosch part at the tuyere level. A cast iron stave cooler 1 is used for the furnace wall zone A from the upper part to the middle part of the shaft.

  As shown in FIG. 2, the cast iron stave cooler 1 is provided with a cooling water passage 1b made of a cast pipe in a disk-shaped stave body 1a. Cooling water is supplied into the cooling water passage 1b. It has a cooling water supply port 1c for supplying and draining water and a cooling water discharge port 1d, and also has a plurality of mounting holes 1d for fixing to the iron shell 4 of the blast furnace. The cast iron stave cooler 1 can be fixed to the blast furnace iron core with a fastening bolt via the mounting hole 1d.

  The cooling equipment in the furnace wall zone B from the lower shaft portion to the belly portion where the heat load of the furnace body is large is based on the provision of the cast iron stave cooler 1 described above. , (B), a copper stave cooler 2 and a steel stave cooler 3 shown in FIGS. 4 (a) and 4 (b) are also used. The copper stave cooler 2 and the steel stave cooler 3 are generally formed by drilling cooling water passages 2b and 3b in the copper plate 2a and the steel plate 3a. The cooling water passages 2b and 3b may be formed by casting holes.

  The example of the copper stave cooler shown in FIG. 3 (b) is an example in which the surface 2f located inside the furnace is formed in an uneven shape in order to reduce the weight, but the surface located inside the furnace of the copper stave cooler 2 is It may be planar. In the figure, 2a is a copper stave body, 2b is a cooling water passage, and has a cooling water supply port 2c and a cooling water discharge port 2d. The blast furnace iron skin 4 is fastened with a fastening bolt through an attachment hole 2e. It is fixed with etc.

In a connection example of dissimilar metals between copper (stave cooler) and steel (iron skin) such as the above copper stave cooler, a cooling water supply path extending from the cooling water passage 2b of the copper stave cooler 2 to the outside of the furnace body 2 h is made of copper, and a steel cap 2 i is used at a portion connected to the connecting pipe 9. Further, the cooling water supply port 2c and the cooling water discharge port 2d penetrating through the iron skin 4 part interpolate the cooling water supply path 2h, and the base 2g is welded to the copper stave cooler 2. As described above, in the case of a copper stave cooler, special welding is performed between different types of copper-steel metals, so it is usually left to an expert in advance and delivered after construction.
In this regard, in the present invention, the iron skin 4, the cooling water supply port 2c, and the cooling water discharge port 2d are all welded between steel and steel, and the iron skin 4 and the cooling water supply port are used in on-site construction and general welding construction. Although 2c and the cooling water discharge port 2d can be easily welded, as described above, the welded portion of the base portion 2g is provided inside the furnace which cannot be repaired during operation.

  The steel stave cooler 3 shown in FIG. 4 is formed by drilling a cooling water passage 3b in a steel stave body 3a. FIG. 4 (a) is a plan view, and FIG. Show. The cooling water passage 3b has a cooling water supply port 3c and a cooling water discharge port 3d for supplying cooling water to the water passage. The blast furnace iron skin 4 is a fastening bolt in the iron skin mounting hole 3e. It is fixed via etc. The steel stave cooler 3 has a cooling water supply port 3c and a cooling water discharge port 3d whose base portion 3g is welded and fixed to the steel stave cooler 3 main body. 3c, the cooling water discharge port 3d is fixed by welding, and there is no problem of dissimilar metal welding in steel-steel welding, but as described above, there is a base 3g welded portion inside the furnace that cannot be repaired during operation. .

  FIG. 5 is a view showing a state in which the steel stave cooler 3 is attached to the iron skin 4. As shown in the drawing, the steel stave cooler 3 is fixed to the iron skin 4 with an attachment bolt 14 via an attachment seat 16, and the head of the bolt 14 is covered with a sealing cap 15 welded to the iron skin 4. It is preferable to use a sealed structure. As a mounting structure of the stave cooler 3, in addition to the illustrated example, the mounting bolt 14 may have a structure that penetrates the stave body 3a. A refractory is filled in the gap between the iron skin 4 and the steel stave cooler 3.

  Next, the cooling equipment in the furnace wall zone C of the Bosch part where the tuyere is located is basically constructed by adopting the same cast iron stave cooler 1 as described above. Alternatively, the entire Bosch may be constituted by the copper stave cooler 2 or the steel stave cooler 3 described above. C ′ shown in the zone C of the Bosch portion indicates the installation position of the tuyere. The zone D, which is the bottom wall of the furnace bottom, has been conventionally cooled by spraying water on the outer surface of the iron shell 4 as described above, but in the present invention, the following equipment is employed instead of the conventional method. To do.

  FIG. 6 shows a preferred embodiment of the present invention, and is an example in which a steel cooling pipe 5 is arranged in an irregular refractory material layer 7 on the side wall of the furnace bottom. In the steel cooling pipe 5 shown in this example, as shown in FIG. 6B, a large number of pipe groups extending in the furnace height direction are arranged in an annular shape having a vertical stripe pattern at predetermined intervals in the furnace circumferential direction. These pipes 5 are provided with horizontal bent portions 5a and 5b (see FIG. 6 (a)) that are bent in the horizontal direction from the upper and lower ends of the pipes 5. It is led out to the outside (outside of the iron skin 4), and is fixed by welding on the outside of the iron skin 4. In addition, these horizontal bent portions 5a and 5b are connected to other cooling pipes 5 'and 5' 'disposed in the upper and lower furnace walls through the connecting pipe 9. Moreover, the uppermost one of the connecting pipes 9 is also connected to the stave cooler 3 and is connected to the cooling pipe 5 and the stave coolers 1, 2 and 3 so as to form one circulation system.

  In the case of such a cooling facility, the cooling pipe 5 does not have a heat insulating layer (non-welded portion) with the stave body as in the cast iron stave cooler 1, so the cooling effect is direct and large, and it is made of steel. Compared to copper stave cooler 2 and steel stave cooler 3, it is cheaper (material cost is 1/10 or less) and can be manufactured at a cost of 1/20 or less of copper stave cooler 2 even if processing costs are included. . Moreover, in the case of the copper stave cooler 2, welding between different metals such as copper and steel is indispensable for attachment to the iron skin 4, but in the first place, welding between these different metals is technically difficult, and welding There is a problem that troubles due to defects are likely to occur. In this respect, when the steel cooling pipe 5 is installed as in the present invention, since all are welded to each other (iron skin), not only the workability is excellent, but also the furnace cooling with high connection reliability. That is, the furnace bottom side wall can be cooled.

  In the copper / steel stave cooler, the cooling water supply port 2c, the cooling water discharge port 2d, the cooling water supply port 3c, and the bases 2g and 3g of the cooling water discharge port 3d are welded to the main body of the copper / steel stave cooler. However, if cooling water leaks from this weld, it is located inside the furnace and cannot be repaired during operation, affecting the life of the blast furnace. However, in the structure by the steel cooling pipe installation by this invention, there is no weld part which becomes a weak part inside a furnace, and even if cooling water leaks from a weld part and it is outside the furnace, it can be repaired during operation.

  In the cooling facility for the bottom wall of the furnace bottom using the steel cooling pipe 5 described above, the length of the furnace wall refractory brick (carbon brick) inside the furnace is 1.5 m as a cooling performance as compared with the conventional copper stave cooler 2. Assuming that the thermal conductivity is 20 w / m · K, if the interval between the cooling pipes 5 is 250 mm, the heat removal amount is only 1.2% lower than the copper stave cooler 2. The temperature of the amorphous refractory material layer 7 in the embedded portion of the cooling pipe 5 is also increased by about 8.5 ° C. as compared with the case where the conventional copper stave cooler 2 is embedded, and the cooling performance with the copper stave cooler 2 is increased. There is no substantial difference.

  In another embodiment of the present invention, the cooling equipment for the bottom wall of the furnace bottom under the tuyere is made of the steel made by placing the furnace wall refractory brick 6 and the iron shell 4 as shown in FIG. There is an example of a membrane structure in which the cooling pipe 5 and the adjacent cooling pipes 5 are connected with a heat transfer plate 8 spanned between them. In this embodiment, an amorphous refractory material layer 7 that is a stamp material or a casting material is filled between the iron skin 4 and the refractory brick 6 so as to surround the cooling pipe 5 of the membrane structure. . That is, in this type of cooling equipment, the above-described membrane-structured cooling pipe 5 is disposed between the iron shell 4 on the side wall of the furnace bottom and the ring-shaped carbon brick 6, and the iron shell 4 and the furnace wall fireproof. Between the ring-shaped carbon bricks 6 constituting the bricks, it is filled with a stamp material that is an amorphous refractory material 7 or is poured into a casting material that is a carbon-based amorphous refractory material. is there.

  If the stamp material or the casting material as the irregular refractory material for the filler described above has a heat transfer characteristic of 10 w / m · K or more, the steel stave cooler 3 or copper is also used for the cooling pipe 5. The cooling performance equivalent to that of the stave cooler 2 is demonstrated. Since this cooling pipe 5 is made of steel, it can be welded with high reliability when it is welded to the iron skin 4 and can also be installed in the factory where the iron skin 4 is manufactured. Can be omitted, which can contribute to the shortening and simplification of repair work.

  In still another embodiment of the present invention, the cooling equipment for the bottom wall of the furnace bottom under the tuyere is constituted by a steel cooling pipe (including a membrane structure) 5 embedded in an amorphous refractory material layer 7. In the blast furnace cooling system, as shown in FIG. 8, not only between the cooling pipes 5, but also a copper stave cooler 2, a steel stave cooler 3, and a cast iron stave cooler 1 are provided as a whole. As shown in FIG. 1, the two are connected to each other via a connecting pipe 9 outside the iron shell 4 so as to form one circulatory system.

  In this embodiment, as shown in FIG. 8, heat exchange is performed in the circulation system formed by the connecting pipe 9, the upper header 10, the lower header 11, the above-described stave coolers 1, 2, 3, and the cooling pipe 5. The vessel 12 and the circulation pump 13 are disposed. In this regard, if only the cooling pipe 5 on the side wall of the furnace bottom is made an independent circulation system, a large number of connecting pipes 9 need to be disposed in a narrow space under the tuyere. By using the cooling water circulation system, the cooling equipment is further simplified.

  In addition, the cooling water circulation system is divided into upper and lower parts, and cooling is performed separately into an upper cooling water circulation system and a lower cooling water circulation system. Even in such a case, the bottom of the furnace is removed from various stave coolers in the furnace wall zone B of the belly part to the furnace wall zone B of the belly part where the furnace body heat load becomes a lower cooling water circulation system and the bosh part where the tuyere is located. Construction and management of the cooling facility can be performed in the same manner by connecting and connecting the steel cooling pipes of the bottom wall part of the furnace bottom of zone D, which is the side wall part, so as to form a series of cooling water circulation systems.

  The cooling water circulation system is divided into the upper and lower parts by dividing the cooling water circulation system into a partial cooling water circulation system and a lower cooling water circulation system. The same is true in that case. From the bottom part of the furnace wall zone B from the lower part of the shaft to the belly part and the various stage coolers of the furnace wall zone C of the Bosch part where the tuyere is located, Construction and management of the cooling facility can be performed in the same manner by connecting and connecting the steel cooling pipes of the bottom wall part of the furnace bottom of zone D, which is the side wall part, so as to form a series of cooling water circulation systems.

  When cooling of the furnace body according to the above-described embodiment of the present invention, in particular, cooling of the bottom wall of the furnace bottom, that is, cooling of the bottom of the furnace with a steel cooling pipe is adopted, cooling is performed as compared with cooling of the furnace body using the copper stave cooler 2. The equipment cost was reduced by 20%.

  Further, in the method using the furnace cooling system with the above-described single circulation system of the present invention, the installation of the stave cooler and the arrangement of the connecting pipe are less than the cooling by the conventional cast iron, copper stave cooler or steel stave cooler. As a result, it was possible to shorten the period of local construction by 0.5 to 1 month.

  The present invention is characterized by cooling of the furnace body cooling equipment of the blast furnace, especially the bottom wall of the furnace bottom. Especially, the cooling pipe embedded structure can be applied as a furnace body cooling method of the shaft part and tuyere part. In addition, this method is effective not only when a blast furnace is newly installed or refurbished, but also as a technique employed when newly establishing, refurbishing or renewing another metallurgical furnace.

It is a figure which shows the outline of the furnace body cooling equipment of a blast furnace. It is a front view of a cast iron stave cooler. It is the front view and side view of a copper stave cooler. It is the front view and side view of a steel stave cooler. It is sectional drawing which shows the iron skin mounting structure of steel stave coolers. It is the fragmentary sectional view of the furnace body cooling facility using the steel cooling pipe, and its enlarged view. It is a basic diagram of the furnace body cooling installation in other embodiment of this invention. It is a basic diagram of the furnace body cooling installation in other embodiment of this invention.

Explanation of symbols

A Shaft upper and middle zone B Shaft lower and belly zone C Bosch zone D Furnace bottom side wall zone 1 Cast iron stave cooler 1a Stave body 1b, 2b, 3b Cooling water passages 1c, 2c, 3c Cooling water supply port 1d, 2d, 3d Cooling water discharge port 1e, 2e Mounting hole 2 Copper stave cooler 2a Copper plate 2g, 3g Base 2h Cooling water supply path 5 Cooling pipe 5 ', 5 "cooling pipe
5a, 5b Horizontal bend 6 Fire-resistant brick 7 Undefined refractory material layer 8 Heat transfer plate 9 Connecting pipe 10 Upper header 11 Lower header 12 Heat exchanger 13 Circulation pipe 14 Mounting bolt 15 Sealing cap 16 Mounting seat.

Claims (9)

Of the blast furnace furnace body, the cooling equipment for the furnace wall above the bosch part was constituted by a stave cooler, and the cooling equipment for the furnace bottom side wall part was arranged between the furnace wall refractory brick and the iron shell. It is composed of a plurality of steel cooling pipes and an amorphous refractory material filled around these steel cooling pipes, and these steel cooling pipes are connected pipes arranged outside the iron skin. Are connected to each other by a connecting pipe disposed outside the iron skin, and the steel cooling pipe is connected to the stave cooler. A blast furnace furnace cooling system characterized by constituting a cooling water circulation system. The blast furnace furnace cooling equipment according to claim 1, wherein the furnace wall above the Bosch part is composed of a shaft part, a belly part and a Bosch part. The blast furnace furnace cooling equipment according to claim 1 or 2, wherein the cooling equipment in the upper part and middle part of the shaft part is a cast iron stave cooler. The said cooling equipment of a shaft lower part, a belly part, and a Bosch part consists of a combination of a cast iron stave cooler or a cast iron stave cooler and a copper stave cooler or a steel stave cooler. Blast furnace furnace cooling equipment. The blast furnace furnace body according to claim 1, wherein the steel cooling pipe on the side wall of the furnace bottom is formed by arranging a plurality of pipes extending in the furnace height direction in an annular shape in the furnace circumferential direction. Cooling equipment. The blast furnace furnace cooling system according to claim 1, wherein the cooling system for the bottom wall of the furnace has a membrane structure in which a heat transfer plate is fixed between adjacent steel cooling pipes. The blast furnace furnace cooling apparatus according to claim 1, wherein the amorphous refractory material is a stamp material or a casting material having a thermal conductivity of 10 w / m · K or more. The blast furnace furnace cooling system according to claim 3 or 4, wherein the cast iron stave cooler has a cooling pipe cast into a cast iron plate-shaped stave body. The blast furnace furnace cooling apparatus according to claim 4, wherein the copper stave cooler and the steel stave cooler have a cooling water passage in a copper rectangular body or a steel rectangular body. .

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