JPH0674656A - Smelting furnace - Google Patents

Abstract

PURPOSE:To obtain a smelting furnace which inhibits a construction site of refractories which need repair work to a minimum by constituting the smelting furnace with a refractories-furnished base furnace body, which is designed to carry out a reaction treatment and an intermediate furnace body in water-cooled panel structure installed to the upper part of the base furnace body and an upper part furnace body installed to the upper part of the intermediate furnace body. CONSTITUTION:A top-blown lance 51 is inserted into a smelting furnace which comprises a base furnace body 17, an intermediate furnace body 18 and an upper part furnace body 19 which are integrated into one piece and then blowing in is started. When smelting is over, a tilting cylinder 25 is operated so that the base furnace body 17 may be tilted and molten steel is tapped from a tapping hole 23. In the case when refractories 21 furnished in the base furnace body 1 is subjected to deterioration, the base furnace body 17 is replaced and the deteriorated refractories are dismantled while new refractories 21 are constructed. The furnace body is divided in three segments in structure, which makes it possible to facilitate repair work and reduce furnace repair time as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refining furnace for carrying out decarburization reactions such as oxidation refining and reduction refining of molten metal, desiliconization reaction, dephosphorization reaction, desulfurization reaction or deoxidation reaction.

[0002]

2. Description of the Related Art Conventionally, as a reaction vessel (refining furnace) using molten metal such as hot metal, a converter 1 (upper-bottom blowing converter) as shown in FIGS. 5 and 6 has been mainly used. There is. In this converter 1, a refractory 3 is installed inside an outer shell 2 made of iron skin, a furnace mouth is reinforced with a furnace mouth metal 4, and a bottom blower opening 5 is provided at the bottom. The method of inserting the upper blowing lance 6 and blowing is generally adopted. The hot metal charged in the converter 1 is divided into molten steel 7 and slag 8 in the process of refining.

The furnace body is supported by a trunnion ring 9 and can be tilted about a trunnion shaft 10 as a fulcrum. A fixed exhaust gas hood 11 is provided above the furnace opening of the converter 1, and a movable skirt 15 including a water-cooled metal pipe 13 and a lifting device 14 is provided between the furnace opening 12 and the fixed exhaust gas hood 11.

In the above-mentioned converter 1, the molten metal (generally molten steel) treatment temperature is as high as 1200 ° C. or higher, and at the end of the treatment it is as high as 1550 ° C. or higher. Further, the above-mentioned conventional converter 1 is provided with a tilting device capable of rotating 360 ° in accordance with the operations such as normal charging and tapping slag, and the workability is ensured in the same structure. Considering the treatment of high-temperature molten steel, it is generally necessary to apply refractory 3 structure to the entire surface of the furnace.

Regarding the converter furnace body, there is also a method of separating the furnace bottom as a means for exchanging the bottom blowhole installed in the furnace bottom and the refractory around it, but this method is basically used for operation and non-operation. During operation, the split portion is mechanically joined to the main furnace body (for example, by bolts or cotters), and the furnace body is provided with refractory material over the entire circumference.

However, the conventional converter 1 has the following inconveniences because it is necessary to form a refractory structure over the entire surface of the furnace. (1) The cost of refractories is large and accounts for a large proportion of the variable work cost. (2) In order to reduce variable costs, durability is improved to extend furnace life, and various additives are added to refractory materials to improve the service life. However, when various additives are added to the refractory, the refractory unit price rises, and accordingly, it is necessary to further extend the life of the furnace, which causes a vicious circle. (3) Furnace repair work takes a long time and limits the operation of the converter. (4) Since the furnace repair is performed based on the life of the refractory, the timing of the furnace repair becomes unclear, and it becomes difficult to secure workers. (5) Furnace repair work requires large-scale capital investment, although automation is advancing. (6) Repairing a refractory requires a large amount of work time and requires an operator who works under adverse conditions. (7) As one of the methods for repairing the refractory material of the furnace body, there is also a method in which the bottom blowhole at the bottom of the furnace body and its periphery are collectively replaced.
However, in the same method, the furnace body and the split part are mechanically joined, but when the joint is cut off and rejoined due to mechanical strain inside the body, which is considered to be due to the heat load (heat history) during operation, There is a problem that it takes time to correct an error and the reliability of mechanical strength is low.

[0007]

The inconveniences in the conventional refining furnace described above can be eliminated by solving the following problems. (1) The refractory cost is large and accounts for a large proportion of the variable work cost, and the vicious cycle of improving the durability of the refractory and increasing the unit price of the refractory is due to the fact that the converter structure covers the entire refractory This is due to the fact that the installation is done, and the work can be done without tilting the converter, and it can be dealt with by reducing the parts that require refractory materials.

(2) In order to shorten the work time of the furnace repair and to minimize the repair work, the refractory parts should be limited as described above and the converter should be functional and functional. It can be dealt with by dividing mechanically.

(3) The converter main body is functionally and mechanically divided, and each furnace body independently and independently supports the strength so that the refractory construction portion at the bottom of the furnace can be quickly processed. However, if the spare furnace bottom refractory is prepared in advance, the repair work of the bottom furnace body after use becomes a work at a low temperature, and the burden of 3K work can be reduced.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems, and aims to improve the work efficiency of furnace repair by limiting the refractory parts as much as possible and functionally dividing the converter. According to claim 1, in a refining furnace that performs oxidation and reduction reactions of hot metal, a bottom furnace body on which a refractory material that performs a reaction process is installed, and a bottom furnace body that is provided above the bottom furnace body,
An intermediate furnace body that promotes reaction, improves thermal tolerance, recovers radiant heat generated in the furnace and sensible heat of exhaust gas, and an upper part that is provided above the intermediate furnace body and that is vertically movable and that collects high-temperature exhaust gas It is characterized by comprising a furnace body.

In the second aspect of the present invention, in order to improve the operability by considering the span in which the upper furnace body can be installed and ensuring the freedom of selection of the tapping and slag slag working method, the bottom furnace in the above refining furnace is used. It is characterized in that it can tilt, including the body and, if necessary, the intermediate furnace body.

According to a third aspect of the present invention, the upper furnace body has a skirt structure formed of water-cooled metal piping in order to more reliably collect the high-temperature exhaust gas.

[0013]

According to the present invention, as described above, the refining furnace is composed of the bottom furnace body, the intermediate furnace body and the upper furnace body.

The bottom furnace body is a portion for carrying out a reaction process,
Refractory is applied only to this bottom furnace body. Therefore, it is possible to limit the construction site of the refractory, improve the work efficiency of the furnace repair, and significantly reduce the cost of the refractory in the variable work cost.

By making the bottom furnace body tiltable, when the furnace body needs to be slightly tilted due to the span in which the upper furnace body can be installed, and the choice of the tapping waste slag working method is free. It works to improve operability, such as securing the degree of operation.
Further, this bottom furnace body is suitably placed on and supported by the operating floor and an appropriate strength member in order to enable quick replacement, and the work load for furnace body replacement is reduced.

The intermediate furnace body promotes reaction, improves heat tolerance,
It is a part that collects radiant heat generated in the furnace and sensible heat of exhaust gas, and acts to exert functions such as promotion of reaction, improvement of thermal margin, radiant heat generated in furnace and recovery of sensible heat of exhaust gas.

The upper furnace body is a part for collecting high temperature exhaust gas. This upper furnace body has a skirt structure with vertically movable water-cooled metal pipes to minimize tilting of the bottom furnace body and intermediate furnace body during hot metal and scrap charging work, and to recover high-temperature exhaust gas. Act to do.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of a refining furnace 16 according to the present invention.

The refining furnace 16 is provided with a bottom furnace body 17 for carrying out a reaction process, and a reaction facilitating reaction, improving the thermal margin, and exposing the radiant heat and exhaust gas generated in the furnace, which are provided above the bottom furnace body 17. It is composed of an intermediate furnace body 18 for recovering heat, and an upper furnace body 19 provided at an upper portion of the intermediate furnace body 18 for vertically moving and recovering high-temperature exhaust gas.

The division position of each of the furnace bodies 17, 18 and 19 will be described. Regarding the division position of the bottom furnace body 17 and the intermediate furnace body 18, the portion where the molten steel 7 is considered to be in contact is the bottom furnace body 17, and the upper portion thereof is the intermediate furnace body 18. Generally, the slag 8 can be supported by a metal panel having a water cooling structure, and the splash generated by the reaction in the furnace can also be handled by a water cooling panel and a water cooling piping structure.

At the dividing position of the intermediate furnace body 18 and the upper furnace body 19, the equipment corresponding to the reaction-promoting lance and the heat source ignition burner, and the portion corresponding to the installation of these replacement jigs are the intermediate furnace body 18, and the upper part thereof. Is the upper furnace body 19. That is,
Various reaction promoting devices and heat recovery devices are installed in the intermediate furnace body 18. If these functions are not required, the upper furnace body 19 can be used instead of the intermediate furnace body 18.

The seal structure of the divided portion is a structure capable of gas purging so as to prevent the gas generated in the furnace from flowing out of the furnace and prevent the slag splash from being deposited on the joint portion. In some cases, a deposit metal removing mechanism may be provided at the joint between the bottom furnace body 17 and the intermediate furnace body 18. The landing metal removing mechanism may use a melting device, but may be a mechanical system.

As described above, the strength of the furnace body divided into three parts is supported by each furnace body, but it is a poisonous gas generated in the furnace by depositing metal-adhered slag at the joint of each part. It is necessary to prevent the outflow of CO gas. Therefore, prevent the accumulation of these by a gas purging and a melting device such as a burner installed in the intermediate furnace body, and for each furnace body, make the outermost circumference of the intermediate furnace body larger than the outermost circumference of the bottom furnace body. It is appropriate to make the outermost periphery of the upper furnace body larger than the outermost periphery of the body so that the joints overlap.

Each furnace body will be described below. The bottom furnace body 17 is obtained by separating only the bottom of the conventional converter structure.
A refractory material 21 is applied to the inner surface of the outer shell 20 made of iron skin, a bottom blowhole 22 is provided on the bottom surface, and a steel tap opening 23 penetrating the outer shell 20 and the refractory material 21 is provided on the side surface. A tilting cylinder mounting portion 24 is provided on one side of the shell 20 so as to project therefrom.

Depending on the position of the tapping hole 23, tapping can be performed without performing the tilting work, but the upper furnace body 1
In some cases, some tilting of the furnace body may be required due to the relationship with the installable span of No. 9, and ensuring the degree of freedom in selecting the tapping slag work method will improve workability. In consideration of the above, it is suitable that the bottom furnace body is supported so as to be tiltable on the operating floor or a pedestal of appropriate strength, and the tilting cylinder 25 is attached to the tilting cylinder mounting portion 24 to slightly tilt the furnace body.

As a method for replacing the bottom furnace body 17, a carriage for replacing the bottom furnace body 17 is used. When replacing the bottom furnace body 17, the bottom furnace body 17 is replaced by a carriage for the furnace body as shown in FIGS. 2 and 3. It is placed on 26 and exchanged. This furnace body truck 26
Installs the lifting jack 29 and the auxiliary jacks 30, 30 on the traveling device 28 that travels on the rail 27, and the lifting jack 29 and the rods 31, 30 of the auxiliary jacks 30, 30.
32 is attached to the lower surface of the mounting table 33. Further, providing a structure for rotating the bottom furnace body 17 on the trolley as needed also leads to quick replacement.

Therefore, the bottom furnace body 17 placed on the furnace body truck 26 has the lifting jack 29 and the auxiliary jack 30.
It is possible to move up and down by the operation of, and to move on the rail 27 by the furnace body carriage 26.

The intermediate furnace body 18 is a cylindrical water cooling panel 34.
And is installed on the upper opening of the bottom furnace body 17. A moving device 35 is provided on the side wall of the water cooling panel 34.
The moving device 35 comprises a pair of moving carriages 36, 36 protruding from the side wall of the water cooling panel 34.
Wheels 37 provided on the lower surface of 36 are placed on rails 38 provided on a girder installed for movement.

From the side wall of the water cooling panel 34, a cooling pipe 40 for supplying cooling water to a water cooling pipe 39 in the water cooling panel 34 is provided. Further, a purging pipe 41 is provided in the upper opening of the water cooling panel 34, and a purging and ingot melting pipe 42 is provided in the lower opening.

From the above-mentioned cooling pipe 40 to the water cooling panel 3
By supplying cooling water to No. 4, the intermediate furnace body 18 can be cooled. Further, by the gas purging from the purging pipe 41 and the purging / metal melting pipe 42, it is possible to prevent the splash and slag generated in the reaction in the furnace from accumulating on the joint portion.

In the above embodiment, the moving device 3
5 uses a movable carriage 36, but when the rail 38 and the supporting device are difficult to install due to the structure of the building, it is possible to fix the intermediate furnace body 18 to the bottom furnace body 17 or to move it. It is also possible to use a crane installed at another position. Further, when the bottom furnace body 17 is tilted during tapping and slag removal work, it is appropriate to provide the intermediate furnace body 18 with a jack 50 for raising and lowering at an appropriate position.

The upper furnace body 19 is an extension of a conventional movable skirt, and has a skirt structure (so-called membrane structure) by a water-cooled metal pipe 43. Metal pipe 4
A pair of long stroke cylinders 44 are attached to the outside of 3, and the rods 45 of the long stroke cylinders 44 are supported by the beams of the building. Further, a cylindrical fixed exhaust gas hood 46 is provided inside the metal pipe 43, and the exhaust gas is guided to the exhaust gas treatment facility through the fixed exhaust gas hood 46.

By operating the long stroke cylinder 45 described above, the upper furnace body 19 can be moved up and down. By making the upper furnace body 19 movable up and down, the crane and the pan can be leaned against each other when charging the hot metal or the like without tilting the bottom furnace body 17 and the intermediate furnace body.

Further, in the upper furnace body 19, the heat load of the exhaust gas and the dust in the exhaust gas and the flying of the metal cause damage to the equipment.
The heat load can be dealt with by effectively recovering the sensible heat of the exhaust gas, which also leads to an improvement in the recovery rate of energy. As for dust and flying metal, contact and adhesion of flying objects are prevented by gas purging.

The tap hole 23 in the bottom furnace body 17 described above
The EBT method was used, but the tapping hole 23 may be another method. For example, as shown in FIG. 4 a, a steel tap 47 may be opened on the bottom surface of the bottom furnace body 17, and the steel tap 47 may be opened and closed by a sliding gate 48.

Also, as shown in FIG. 4b, the bottom furnace body 17
It is also possible to use a blast furnace tapping method in which a tap hole 49 is opened near the center of the bottom surface of the blast furnace.

A procedure for refining using the furnace body described above will be described. First, the furnace body carriage 26 on which the bottom furnace body 17 is placed is moved to the work position. Here, the lifting furnace 29 and the auxiliary jack 30 are used to raise the bottom furnace body 17, the rod of the tilting cylinder 24 is attached to the tilting cylinder mounting portion 24, and the bottom furnace body is set at a predetermined position. Then, the intermediate furnace body 18 is moved by the moving carriage 36 to position the intermediate furnace body 18 on the bottom furnace body 17 installed at the work position. As described above, the bottom furnace body and the intermediate furnace body, which are installed at the predetermined positions, also correspond to the reaction process as the basic position until the refractory replacement or the repair work is performed.

Further, the long stroke cylinder 44 is driven to move the upper furnace body 19 to the upper position. In this state, after loading the hot metal into the furnace, the long stroke cylinder 44 is driven to install the upper furnace body 19 on the intermediate furnace body 18.

Thereafter, the upper blowing lance 51 (FIG. 1) is inserted into the refining furnace 16 in which the bottom furnace body 17, the intermediate furnace body 18, and the upper furnace body 19 are integrated, and blowing is performed. When the refining is completed, basically, the steel is tapped from the tapping hole 23 of the bottom furnace body 17 without tilting. In addition, the slag treatment can be performed by raising the upper furnace body 19 and the intermediate furnace body 18 and tilting the bottom furnace body 17. Then, the tilting cylinder is driven to tilt the bottom furnace body 17, and molten steel is tapped from the tapping port 23.

Refining is performed according to the procedure described above, but when the refractory 3 installed in the bottom furnace body 17 is deteriorated, the bottom furnace body 17 is replaced, and the deteriorated refractory 3 is dismantled. Install a refractory material 3. In this case, the rod of the tilting cylinder 25 attached to the tilting cylinder mounting portion 24 of the bottom furnace body 17 is removed, the lifting jack 29 and the auxiliary jack 30 are driven to lower the bottom furnace body 17, and the furnace body carriage 26 Is moved to the refractory construction site and the refractory 3 is disassembled and construction work is performed.

In repairing the refractory 3 of the bottom furnace body 17, a plurality of, for example, two furnace body carriages 26 on which the bottom furnace body 17 is mounted are provided (FIG. 3), and one bottom furnace body 17 is used. If the refractory 3 is repaired in the other bottom furnace body 17 while the refining work is being performed and the two bottom furnace bodies 17 are used alternately, the refining work can be performed efficiently. it can.

[0042]

As described above, according to the present invention, the refining furnace for oxidizing and reducing the hot metal is provided in the bottom furnace body on which the refractory material for the reaction treatment is applied, and in the upper part of the bottom furnace body. It is composed of an intermediate furnace body having a water-cooled panel structure and an upper furnace body provided above the intermediate furnace body. Further, the bottom furnace body has a structure in which steel can be tapped without tilting or with a slight tilting.

Since the refractory material needs to be applied only to the portion in contact with the molten steel, it may be applied only to the inner surface of the bottom furnace body of the furnace body having the three-part structure. Therefore, it is possible to minimize the number of refractory construction sites that require repair work.

Therefore, it is possible to reduce the cost of the refractory material, which has conventionally occupy a large proportion of the variable work cost. Further, since the furnace body has a three-part structure, repair work is facilitated and the work time for furnace repair can be significantly shortened.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of a refining furnace according to the present invention.

FIG. 2 is an explanatory diagram showing a divided state of an embodiment of a refining furnace according to the present invention.

FIG. 3 is an explanatory view showing a replacement state of a bottom furnace body in an embodiment of a refining furnace according to the present invention.

FIG. 4 is another embodiment of the bottom furnace body of the refining furnace according to the present invention, in which a is a sectional view of the bottom furnace body having a tapping port by the sliding gate system, and b is a tapping port by the blast furnace tapping system. It is sectional drawing of the bottom furnace body which has.

FIG. 5 is a cross-sectional view showing a configuration of a conventional converter.

FIG. 6 is a cross-sectional view showing a state in which a fixed exhaust gas hood and a movable skirt are provided in a conventional converter.

[Explanation of symbols]

 16 Refining Furnace 17 Bottom Furnace 18 Intermediate Furnace 19 Upper Furnace 21 Refractory 24 Tilt Cylinder Attachment 25 Tilt Cylinder 34 Water Cooling Panel 43 Metal Pipe

Claims (3)

[Claims] 1. A refining furnace for performing oxidation and reduction reactions of molten metal, a bottom furnace body on which a refractory is applied, which carries out a reaction treatment, and a reaction promotion and thermal allowance provided on an upper part of the bottom furnace body. The intermediate furnace body with a water-cooled panel structure that recovers radiant heat and sensible heat of exhaust gas generated in the furnace, and the upper furnace that is provided above the intermediate furnace body and that can move up and down and collects high-temperature exhaust gas A refining furnace characterized by consisting of a body and. 2. The refining furnace according to claim 1, wherein the bottom furnace body is tiltable. 3. The refining furnace according to claim 1, wherein the upper furnace body has a skirt structure composed of water-cooled metal pipes.