JPH06117778A - Method and apparatus for cooling furnace casing of molten steel-refining furnace - Google Patents

Abstract

PURPOSE:To provide a furnace casing-cooling apparatus which prevents thermal deformation to be caused to the furnace casing of a converter. CONSTITUTION:The furnace casing of a converter 17 is cooled by supplying a cooling liquid to three supply lines 2, 2, 2 located around the furnace casing and by discharging it into discharge lines 9, 9, 9 connected to the supply lines 2, 2, 2. At this time, if the leakage of the cooling liquid occurs, it is stopped that the cooling liquid is supplied to the supply line 2 on which the leakage occurs, and a refrigerant gas is supplied through a refrigerant gas pipe-line 8, and thus the cooling liquid remaining therein is forcibly sent off and both the supply line 2 and the discharge line 9 are cooled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a furnace body cooling method and apparatus for a molten steel refining furnace capable of preventing thermal deformation and the like generated in a molten steel refining furnace such as a converter. Relates to a furnace body cooling method and apparatus for a molten steel refining furnace, which uses not only a cooling liquid such as cooling water but also a refrigerant gas such as air.

[0002]

2. Description of the Related Art The furnace body of a molten steel refining furnace (hereinafter referred to as "converter" as an example in this specification) is exposed to high temperatures during operation, and therefore heat generated during repeated use is generated. Deformation progresses due to stress, and in the worst case, it may become unusable. Therefore, conventionally, various proposals have been made for the purpose of preventing the deformation of the furnace body of the converter, but the water cooling method is most preferable in consideration of the cooling efficiency.

For example, Japanese Patent Publication No. 4-22966 discloses that the cooling of the furnace body is controlled according to the thickness of the brick lining the converter.
Cooling water on the outer wall surface of the converter (hereinafter, "cooling water" will be described as an example of "cooling liquid" in the present specification)
A pipe unit through which water flows through the pipe unit is arranged and cooling water is supplied on the water supply side of this pipe unit via three independent control valves for each system, while on the drain side one cooling water passing through the control valve is supplied. There has been proposed a cooling device configured to be collected in a system and discharged.

However, in this cooling device, if a trouble such as a cooling water leak occurs at one place of the pipe unit, a steam explosion may occur due to the leaked cooling water. It is necessary to stop the water supply and repair the site where the cooling water leak has occurred. Therefore, the furnace body cannot be cooled until the repair is completed and the cooling water can be supplied, and the furnace body is deformed.

Further, although the cooling water supply is stopped immediately when a cooling water leak occurs in this device, there is a risk that the cooling water accumulated in the pipe unit may cause a steam explosion even after the supply is stopped. It is extremely problematic in operation.

As a device that uses cooling water for cooling the furnace body of a converter and there is no fear of causing a steam explosion even if this cooling water leaks, Japanese Utility Model Publication No. 57-150798 discloses a device outside the converter. An apparatus has been proposed in which a cooling pipeline is installed on a wall surface, and pressurized water and compressed air as a cooling medium are constantly flowed in the cooling pipeline to perform cooling. However, in this method, the pressurized water and the compressed air are mixed in a mist form in the cooling pipeline, so it is impossible to recover the air after use, and the end of the cooling pipeline is always open to the atmosphere. It is also disadvantageous in terms of energy cost.

[0007]

As described above, the conventional converter cooling methods have the problems listed below. If a cooling water leak occurs when cooling by flowing cooling water inside the pipe installed on the outer wall of the furnace body, a steam explosion may occur.To prevent this steam explosion, gather in one system. The supply of the cooling water flowing through the inside of the water supply pipe and the drainage pipe, which have been installed, has to be temporarily stopped, and during this time, the furnace body is deformed due to the inability to cool.

A method of utilizing a mixed fluid of pressurized water and compressed air as a cooling medium in order to reduce the risk of steam explosion even when a leakage of cooling water from a pipe for circulating the cooling water occurs, is a method of recovering compressed air. Energy cost rises significantly.

That is, in the conventional converter cooling method, the risk of a steam explosion occurring when a cooling water leak occurs cannot be eliminated. Therefore, cooling the converter by a water cooling system is a viewpoint of maintaining safety. Was thought to be impossible. Furthermore, the cooling method of the water-cooled converter with improved safety is disadvantageous in terms of energy cost and difficult to realize.

It is an object of the present invention to provide a furnace body cooling technique for a molten steel refining furnace which can prevent thermal deformation or the like occurring in the molten steel refining furnace such as a converter. Is to provide a furnace body cooling technology for a molten steel refining furnace that uses not only cooling water but also a refrigerant gas such as air.

In other words, the object of the present invention is advantageous in terms of energy cost, there is no danger of steam explosion even when a cooling water leak occurs, and the cooling effect can be sufficiently ensured. It is to provide a reliable technology for cooling a molten steel refining furnace body.

[0012]

As a result of intensive studies to solve the above problems, the present inventor has found that a plurality of converter furnace bodies, such as a furnace mouth ring, a furnace mouth flange, and an upper iron shell, are used. Multiple sets of cooling water supply and discharge channels for supplying and discharging cooling water for each required cooling site are installed independently on the outer wall surface of the converter, and cooling water is provided in these supply and discharge channels. When a trouble such as a leak occurs, a refrigerant gas such as air can also be made to flow, and during normal operation, the flow rate, temperature and pressure of the cooling water are individually detected to determine whether or not a cooling water leak has occurred. In addition to constant monitoring, when trouble occurs, the supply of cooling water is immediately stopped, and the cooling water that accumulates in the pipe where the trouble occurs is pumped and removed with refrigerant gas to eliminate the risk of steam explosion. By continuing to supply the refrigerant gas then further to eliminate the cause of the cooling water leakage can be continuously performed furnace cooling of the converter, and found that can solve the above problems, and completed the present invention.

The gist of the present invention is that the cooling liquid is supplied to one or more supply passages arranged around the molten steel refining furnace to cool the furnace body and connected to the supply passages. In the furnace body cooling method of the molten steel refining furnace that discharges the cooling liquid from the discharge passage, if the cooling liquid leaks, the supply of the cooling liquid to the leaked supply passage is stopped. In the method for cooling a furnace body of a molten steel refining furnace, a refrigerant gas is supplied to a supply path, and the accumulated cooling liquid is pressure-fed and a supply path and an exhaust path connected to the supply path are cooled. is there.

From another aspect, the present invention is an apparatus for cooling a furnace body of a molten steel refining furnace, which comprises (i) molten steel refining of, for example, a furnace port ring, a furnace port flange and an upper steel shell. Independently provided around the furnace body to cover a plurality of parts of the furnace, a plurality of sets of supply paths and discharge paths for the cooling liquid,
(ii) a refrigerant gas supply system connected to each of the plurality of supply paths, (iii) a refrigerant gas discharge valve provided in each of the plurality of discharge paths, and (iv) flowing inside the supply path and the discharge path. A combination of a detector that detects the flow rate, temperature, and pressure of the cooling liquid and (v) a control device for the cooling liquid that controls the flow rate, temperature, or pressure according to the output signal from the detector. A furnace cooling device for a molten steel refining furnace.

In the present invention, the "refrigerant gas" means a cooling gas which flows through the inside of the pipe heated by the radiant heat from the furnace body of the molten steel refining furnace to cool the pipe, and air can be exemplified. .

[0016]

The operation of the present invention will be described in detail below. In the furnace body cooling method according to the present invention, normally, the cooling water is supplied to the inside of the pipe arranged around the molten steel refining furnace to cool the furnace body. In addition, in order to eliminate the risk of steam explosion, when supplying cooling water, in the supply path and discharge path,
At least the flow rate, temperature and pressure of the cooling water are constantly monitored, and if these values are out of the proper range, it is judged that cooling water leakage has occurred and the supply of cooling water is immediately stopped.

When a trouble such as a cooling water leak occurs, the supply of the cooling water to the supply passage in which the trouble has occurred is stopped, and the refrigerant gas is supplied to the supply passage and the accumulated cooling water is pumped and supplied. The passage and the discharge passage connected to the supply passage are cooled. It should be noted that the supply of the refrigerant gas to the supply passage and the discharge passage may be performed by appropriate means, and it is not necessary to limit it to a specific means. For example, a refrigerant gas pipe may be connected to a part of the supply path via a gas purge valve.

Therefore, according to the present invention, the cooling water that has accumulated in the supply passage and the discharge passage where the cooling water has leaked can be quickly discharged, and the risk of steam explosion due to the accumulation of the cooling water can be eliminated. Further, since the supply passage and the discharge passage where the supply of the cooling water is stopped can be continuously cooled by the refrigerant gas, it is possible to eliminate the deformation of the furnace body. Further, the refrigerant gas only needs to be supplied from the time when the supply of the cooling water is stopped after the trouble occurs to the time when the cooling water is restored, and it is not necessary to always supply it, which is advantageous in terms of energy cost.

On the other hand, in the furnace body cooling device according to the present invention,
Since the cooling water supply path and cooling water supply path are provided separately for each part of the converter that requires cooling, for example, via the furnace opening ring, the furnace opening flange, and the upper shell, for example, problems such as cooling water leakage can occur. In the case of occurrence of the trouble, it is possible to continue supplying the cooling water as it is to the supply passage and the discharge passage where no trouble occurs, and it is possible to suppress the deterioration of the cooling effect to the minimum.

In the furnace body cooling apparatus according to the present invention, since a refrigerant gas such as air can be flown through the cooling water supply passage and the discharge passage, trouble occurs and the refrigerant stays in the supply passage and the discharge passage. The cooling water can be immediately pumped and removed by the refrigerant gas, and the risk of steam explosion can be quickly eliminated. Further, since the supply gas and the discharge path where the trouble has occurred and the cooling water is not supplied can be cooled by the refrigerant gas, it is possible to prevent the deformation of the furnace body when the trouble occurs.

In the furnace body cooling apparatus according to the present invention, the refrigerant gas is not always supplied, but is allowed to flow only from the time when the supply of the cooling water is stopped after the trouble occurs to the time when the cooling water is restored. Therefore, the amount of the refrigerant gas used can be suppressed to a necessary minimum, and an increase in energy cost can be suppressed.

Further, the furnace body cooling device according to the present invention is
When a trouble occurs, it is only necessary to stop the supply of the cooling water and supply the refrigerant gas, so that the operation can be performed reliably and safely. The refrigerant gas supplied to the supply passage and the discharge passage is discharged from the refrigerant gas discharge valve provided in each of the one or more discharge passages.

As described above, according to the present invention, in brief, the possibility of steam explosion and thermal deformation of the furnace body, which are the drawbacks of the converter water cooling system using only cooling water, can be eliminated by using the refrigerant gas. . Further, the present invention will be described in detail with reference to examples, but this is an example of the present invention and the present invention is not limited thereto.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view showing a structural example of a furnace body cooling device according to the present invention.
The water supply pipe 2 which is a water supply channel located upstream of the furnace and the drain pipe 9 which is a discharge path located downstream of the furnace body cooling valve station 1 may be one system that joins, or a cooling required portion of the converter. There may be multiple systems divided for each.
The present embodiment is an example of one system.

In the embodiment shown in FIG. 1, three parts, that is, a furnace port ring, a furnace port flange and an upper iron shell, are selected as the cooling required parts of the converter 17, and in order to cope with these, the water supply pipe 2 and the drain pipe are selected. Shown is the case where 9 is divided into 3 systems and installed.

The feed water pipe 2 is once divided into three systems in parallel in front of the converter 17, and the feed water temperature detectors 3 and 3 are provided for each system.
The water supply pressure detector 4 and the water supply flow rate detector 5 are installed in series, and the water supply valve 6 is installed downstream of these detector groups.
Then, on the downstream side of the water supply valve 6, a refrigerant gas pipe 7 such as air is connected to each of the three systems via a gas purge valve 8.

These three systems of supply passages for cooling water are arranged around the furnace opening ring, the furnace opening flange and the upper iron shell by appropriate means so that the converter 17 can be cooled. It

On the other hand, the three drain pipes 9, 9, 9 on the outlet side of the furnace body
In the middle of the process, the desorption pipes 10, 10, 10 are connected, and the refrigerant gas pressure-fed inside the drain pipe is released to the atmosphere via the exhaust valves 11, 11, 11, respectively.

A drainage temperature detector 12 is provided upstream of the diffusion pipes 10, 10, 10 of the three drainage pipes 9, 9, 9.
A drain valve 13, a drain flow rate detector 14 and a drain pressure detector 15 are provided after the diffusion pipe 10, and then merged into one system. It is not always necessary to merge into one system, and three systems may be left as they are.

Each detector for water supply / drainage installed in this valve station 1 (water temperature detector 3, water temperature detector 12, water pressure detector 4, water pressure detector 15, water pressure detector 5, water flow detector 5 and water) The measured value by the flow rate detector 14) is converted into an electric signal and input to the control / arithmetic unit 16. The control / arithmetic unit 16 determines that a cooling water leak has occurred and outputs an alarm when the various measured input values reach predetermined preset control values.

Next, a furnace body cooling method according to the present invention will be described with reference to FIG.
Will be described with reference to. In the present invention, in FIG. 1, when a cooling water leak due to a crack or the like occurs in the water supply pipe 2 or the drain pipe 9 of the converter furnace body 17, a temperature difference between the water temperature detector 3 and the water temperature detector 12, The pressure difference between the feed water pressure detector 4 and the drainage pressure detector 15, and the flow rate difference between the feedwater flow rate detector 5 and the drainage flow rate detector 14, or the drainage temperature detector 12, the pressure detector 15, and the flow rate detector 14, Detecting either of the values being out of the specified range as the occurrence of cooling water leakage,
Output an alarm.

When the control / arithmetic unit 16 first outputs an alarm, the water supply valve 6 of the path which is judged to have leaked the cooling water after a certain time is closed, and at the same time, the gas purge connected to the same system is performed. Open valve 8. After that, by closing the drain valve 13 and opening the drain valve 11, the refrigerant gas rapidly flows inside the water supply pipe 2 and the drain pipe 9 of this system, so that the cooling water accumulated in the pipe in which the trouble has occurred is removed. By removing it from the diffusion pipe 10 to the outside of the system, it is possible to quickly eliminate the risk of steam explosion due to the retention of cooling water.

After that, by continuing to flow this refrigerant gas until the recovery of the cooling water leakage is completed, the cooling of the furnace body can be continued by the cooling gas instead of the cooling water. Four conventional types using the present invention as described above and compressed air only, water only, steam only, water + compressed air alone (the technique described in Japanese Utility Model Publication No. 57-150798) as cooling media for the supply passage and the discharge passage. With other cooling technologies in terms of cooling efficiency, energy cost and safety. The results are shown in Table 1.
Are shown together.

In Table 1, the cooling effect is shown by numbering the cooling media in descending order of the cooling effect by measuring the temperature of the cooling medium. Also, the energy costs are numbered sequentially from the cheapest. Further, regarding the safety, the good ones were represented by ◯, and the poor ones were represented by x.

[0035]

[Table 1]

As is clear from the above examples, the example of the present invention is advantageous in terms of cost, there is no danger of explosion when water leaks, and the cooling effect can be secured.

[0037]

As described in detail above, according to the present invention, the effects listed below can be obtained.

(I) The cooling water retained in the supply passage and the discharge passage where the cooling water leaked can be quickly discharged. (ii) It was possible to eliminate the risk of steam explosion due to the retention of cooling water. (iii) The supply path and the discharge path where the supply of cooling water is stopped
Since the cooling can be continued by the refrigerant gas, the deformation of the furnace body can be eliminated. (iv) The refrigerant gas may be supplied only from the time when the supply of the cooling water is stopped to the time when the cooling water is recovered after the trouble has occurred, and it is not necessary to always supply the refrigerant gas, which is advantageous in terms of energy cost.

In other words, according to the present invention, there is a cost advantage, there is no danger of steam explosion even when a cooling water leak occurs, and the cooling effect can be sufficiently secured.
Furthermore, we were able to provide safe and reliable furnace body cooling technology for molten steel refining furnaces. The significance of the present invention having such effects is extremely remarkable.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration example of a furnace body cooling device according to the present invention.

[Explanation of symbols]

 1: Valve station 2: Water supply pipe (supply line) 3: Water supply temperature detector 4: Water supply pressure detector 5: Water supply flow rate detector 6: Water supply valve 7: Refrigerant gas pipe 8: Gas purge valve 9: Drain pipe (discharge) 10): Dispersion pipe 11: Discharge valve 12: Waste water temperature detector 13: Drain valve 14: Waste water flow detector 15: Waste water pressure detector 16: Control / arithmetic unit 17: Converter

Claims (2)

[Claims] 1. A cooling liquid is supplied to one or more supply passages arranged around a molten steel refining furnace to cool the furnace body, and the cooling liquid is supplied from an exhaust passage connected to the supply passage. In the furnace body cooling method of the molten steel refining furnace to be discharged, when the leakage of the cooling liquid occurs, while stopping the supply of the cooling liquid to the supply path where the leakage occurred, the refrigerant gas to the supply path. A method for cooling a furnace body of a molten steel refining furnace, which comprises supplying and feeding the retained cooling liquid under pressure and cooling the supply path and a discharge path connected to the supply path. 2. An apparatus for cooling a furnace body of a molten steel refining furnace, comprising: (i) a cooling liquid which is independently provided around the furnace body so as to cover a plurality of portions of the molten steel refining furnace. A plurality of sets of supply passages and discharge passages, (ii) a refrigerant gas supply system connected to each of the plurality of supply passages, and (iii) the refrigerant gas discharge valve provided in each of the plurality of discharge passages ,
(iv) a detector for detecting the flow rate, temperature and pressure of the cooling liquid flowing inside the supply passage and the discharge passage, and (v) the flow rate, temperature or pressure depending on the output signal from the detector. A furnace body cooling device for a molten steel refining furnace, which is provided in combination with a control device for a cooling liquid to be controlled.