JPH09157730A - Vacuum degassing equipment of vessel lifting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide vacuum degassing equipment of a vessel lifting system to which a lance device designed to blow oxygen, gaseous fuel, powder, etc., in the vacuum chamber of the vacuum degassing equipment of the vessel lifting system is applicable without any problems in terms of the equipment and operation. SOLUTION: A supporting frame 22 is disposed on a supporting stand 2 which supports the vacuum chamber 1 immersed at its lower part into molten metal 5 housed in a ladle 6 and is lifted by a lifting device. The lance device 10 freely liftably supports the lance 8 for blowing the oxygen, gaseous fuel, powder, etc., into the vacuum vessel 1 is disposed at the supporting frame 22. The lance device is simultaneously lifted together with the vacuum vessel 1. The vacuum chamber 1 is divided to a top cap section 10 to be fixed to the supporting stand 2 and a lower vessel 1u. The top cap section 10 is fixed to the supporting stand 2 and the lower part 1u is made attachable and detachable to and from the top cap part 10. Only the lower part 1u is exchanged to lessen the burden for the exchange work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum degassing equipment of a tank elevating system used for vacuum degassing and refining in a steelmaking process, and more specifically, a lower part is immersed in molten steel in a ladle. The present invention relates to a facility structure of a lance device that supports a lance for blowing oxygen, fuel gas, powder, etc. in a vacuum chamber that can be raised and lowered.

[0002]

2. Description of the Related Art For example, in the field of iron and steel, DH type vacuum degassing equipment and R are generally used for dehydrogenation of molten steel, degassing such as denitrification, vacuum decarburization, cleaning of molten steel and adjustment of components.
H-type vacuum degassing equipment and other types of vacuum degassing equipment are used, and in recent years, in order to improve the efficiency of operation in these vacuum degassing equipment, oxygen, fuel gas, powders are placed in the vacuum tank. It has been proposed to install a lance device that supports a lance for blowing air etc. so that the lance can be moved up and down. Usually, in these vacuum degassing equipment, it is necessary to operate the lower tank of the vacuum tank or the dip pipe formed in the lower tank by immersing it in the molten steel in the ladle. It is necessary to have a mechanism to make it.

Conventionally, when a lance device for supporting a lance for injecting oxygen, fuel gas, powder, etc. in a vertically movable manner is installed in the vacuum chamber, the vacuum chamber 1 is supported as shown in FIG. 3, for example. Since it is fixed to the gantry 2, an elevating table 4 which is moved up and down by an elevating device 3 such as a hydraulic cylinder is arranged below the vacuum chamber 1, and a ladle 6 containing molten steel 5 is moved onto the elevating table 4. The elevation table is raised to immerse the dip pipe 7 in the lower portion of the vacuum tank 1 in the molten steel 5 in the ladle 6 to perform vacuum degassing operation.

In the vacuum degassing equipment of such a tank fixing system (ladle raising / lowering system), when the lance device 10 including the lance 8 and the lance lifting device 9 for raising and lowering the lance is installed, the vacuum chamber 1 above the vacuum chamber 1 is installed. The lance lifting device 9 is attached to the pillar 12 of the building 11, and the opening 13 for inserting the lance 8 and the sealing device 14 are provided in the canopy portion of the vacuum tank 1 so that the structure of the facility does not hinder the operation and the vacuum removal is performed. The function and purpose of the lance device in the gas facility can be achieved.

However, in the vacuum degassing equipment,
Instead of the tank fixing method, the tank lifting method that raises and lowers the vacuum tank (fixed ladle method) is also used. Examples of this tank elevating system include a lever type (lever system) elevating system, a four-column cylinder elevating system, and a winch elevating system.

The lever type (lever type) lifting system is
As shown in FIG. 4, the support base 2 that supports the vacuum chamber 1 is
The support stand 15 is rotatably supported up and down about a support shaft 16, and a lift 17 such as a hydraulic cylinder is used to move the support stand 2 up and down through a counterweight 18 to move the vacuum tank 1 up and down. In this lever type lifting method, the vacuum chamber 1 is moved up and down so as to draw an arcuate locus cb around the support shaft 16 of the support base 15.

The four-column cylinder lifting method is shown in FIG.
As shown in FIG. 4, the support base 2 supporting the vacuum chamber 1 can be lifted and lowered by a lifting device 17 such as a hydraulic cylinder.
It is structured such that the four columns are simultaneously moved up and down by the elevating device 17, and in this four-column cylinder up-and-down method, the vacuum chamber 1 is vertically moved up and down.

In the winch raising / lowering method, as shown in FIG. 6, the support base 2 supporting the vacuum chamber 1 is attached to the winch 2
At 0, the vacuum chamber 1 is hoisted and unwound via the chain 21 to vertically move up and down.

However, in these vacuum evacuation equipment of the tank elevating type, degassing is mainly performed, and in order to blow oxygen, fuel gas, powder, etc. into the vacuum tank, the vacuum tank is used. Only a fixed lance having a fixed opening directly provided in the above is implemented as an example, and the examples in which the lance device capable of moving up and down is combined with the vacuum degassing equipment are all tank fixing methods, that is, In the actual situation, which depended on the pan raising / lowering method, there is no actual case in the past where a lance device supported to be able to move up and down is directly provided in a vacuum degassing equipment of a tank raising / lowering method.

If it is attempted to directly attach the lance device to the vacuum degassing equipment of the lever type lifting system, the four column cylinder lifting system, and the winch lifting system of the tank lifting system, the following problems will occur. It couldn't be realized because of the points.

First of all, in the lever type lifting system, the lifting path of the vacuum chamber is arcuate, whereas the lifting path of the lance is completely different, but it is a vertical line. When the thermal deformation occurs, the position of the core of the lance hole on the canopy of the vacuum chamber and the position of the core of the lance that moves up and down do not match finely, and insert the lance into the vacuum chamber while maintaining high sealing performance. And the lance could not be inserted into the vacuum chamber until the vacuum chamber stopped at the operating position.

On the other hand, in the 4-column cylinder lifting system and the winch lifting system, the height of the vacuum chamber is changed according to the change of the vacuum degree in the vacuum chamber during operation, or the position of the molten metal is changed due to the vacuum degree. Accordingly, it is necessary to change the lance height position frequently.

However, when the vacuum chamber is frequently moved up and down with the lance inserted in the vacuum chamber, even if the lance is moved up and down in synchronism with the vertical movement of the vacuum chamber, a slight deviation occurs, and the lance and the vacuum chamber are vacuumed. The tank moves up and down relatively, and the lance core and the lance hole core of the sealing device are slightly deviated from each other. Since the property deteriorates, the degree of vacuum in the vacuum chamber decreases, and the degree of vacuum in the vacuum chamber cannot be secured stably, so that stable operation cannot be performed.

Further, since the lifting seal device is heavily worn and shortens its life, there is a problem that the number of repairs and replacements is increased, and it is necessary to frequently align the lance core and the lance hole. There is also a problem that the maintenance time is long, the cost is increased, and the productivity is lowered.

[0015]

DISCLOSURE OF THE INVENTION The present invention relates to a vacuum evacuation equipment of a chamber elevating system, which is equipped with a lance device for blowing oxygen, fuel gas, powder, etc. in a vacuum chamber. It is intended to provide a vacuum evacuation equipment of a tank elevating system which can be applied without any problem.

[0016]

Means for Solving the Problems The first invention of the present invention is:
In the vacuum degassing equipment of the tank lifting type, oxygen in the vacuum tank,
A vacuum evacuation equipment of a tank elevating system characterized in that a lance device for supporting a lance for injecting fuel gas, powder, etc. to be lifted up and down is directly arranged in the vacuum evacuation equipment of the tank elevating system. . A second invention of the present invention is that, in a vacuum evacuation equipment of a tank elevating system, a supporting frame is arranged on a supporting frame which supports a vacuum tank immersed in a molten metal contained in a ladle and is elevated by an elevating device. A lance device for supporting a lance for blowing oxygen, fuel gas, powder, etc. into the vacuum chamber is provided on the support frame so that the lance can be moved up and down, and the lance device is moved up and down simultaneously with the vacuum chamber. It is a vacuum degassing treatment facility of a tank elevating type characterized by the following. In a third aspect of the present invention, in the first aspect, the vacuum chamber is divided into a canopy portion that is fixed to the support frame and a lower chamber, the canopy portion is fixed to the support frame, and the lower portion is attached to the canopy part. This is a vacuum degassing equipment of the tank lifting type, which is detachable. A fourth invention of the present invention is a tank-lifting vacuum degassing equipment characterized in that the vacuum degassing equipment in the first to third inventions is an RH type vacuum degassing equipment.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the examples shown in FIGS. (Embodiment 1) FIG. 1 shows a lance device for injecting oxygen or fuel gas into a vacuum chamber according to the present invention.
1 is a conceptual illustration of an example of vacuum degassing equipment. In the RH type vacuum degassing equipment shown here, in order to fix the position of the ladle 6 during operation and to immerse the molten steel 5 contained in the ladle 6 into the dipping pipe 7 under the vacuum tank 1. Then, the vacuum tank 1 is fixed to a support frame 2 supported by four support columns 19 which are vertically moved by a hydraulic cylinder (elevating device) 17,
A vacuum evacuation equipment of a tank elevating system by a four-column cylinder elevating system is employed, in which the vacuum tank 1 is elevated and lowered by the hydraulic cylinder 17 via the four support columns 19 and the support base 2.

In this RH type vacuum degassing equipment of the chamber lifting type, since the lance device 10 for blowing oxygen or fuel gas into the vacuum chamber 1 is installed, the support frame 2 supporting the vacuum chamber 1 is of a gate type. A support frame 22 is arranged, a column 23 is erected on the support frame, and a lance lifting device 9 is installed on the column.

The hoisting device 9 has a supply hose 24 connected to a supply source (not shown) of oxygen or fuel gas.
A lance device 10 is formed by inserting a lance 8 connected through the lance 8 into the lance hole 13 of the canopy portion of the vacuum chamber 1 and the sealing device 14 so as to be movable up and down.

In the vacuum degassing operation, the hydraulic cylinder 17 raises the support column 19 to evacuate the vacuum chamber 1 to a position where it does not interfere with the ladle 6 carried in below, and the lance lifting device 9 causes the lance to move. Adjust the position of 8. Then, after the ladle 6 is carried into the operating position below the vacuum tank 1, the vacuum tank 1 is lowered by the hydraulic cylinder 17 through the support column 19, and the lower immersion pipe 7 is placed in the molten steel 5 in the ladle 6. Dip to a predetermined depth and lift the lance 9
Vacuum chamber 1 with the tip position of the lance 8 adjusted by the vacuum degree
The molten steel 5 sucked up and circulated therein is positioned at a predetermined position on the molten metal surface.

Oxygen, fuel gas, powder, etc. are supplied from the supply source via the supply hose 24 at the required timing to the lance 8.
Then, an appropriate amount is blown into the molten steel 5 circulating in the vacuum chamber 1 to carry out the vacuum degassing operation. 2 in the figure
An exhaust gas duct 5 discharges (sucks) the dust-containing exhaust gas from the vacuum chamber 1.

In this lance device, during non-treatment (standby), oxygen or fuel gas may be supplied into the vacuum chamber to keep the vacuum chamber in heat or to melt the metal. .

In this embodiment, in the vacuum degassing equipment of the tank raising and lowering system by the four column cylinder raising and lowering system,
It is characterized in that a gate-shaped support frame 22 is arranged on a support frame 2 supporting the vacuum chamber 1, a column 23 is erected on this support frame, and the lance device 10 is installed on this column.

That is, the lance device 10 and the vacuum chamber 1 are fixed in position by arranging the lance device 10 on a column 23 standing on a support frame 22 provided on a support frame 2 to which the vacuum chamber 1 is fixed. Then, the vacuum chamber 1 and the lance device 10 can be moved up and down synchronously with the lance 8 and the canopy portion of the vacuum chamber 1 and the central positions of the lance holes 13 of the sealing device 14 always aligned with each other. .

By doing so, even when the vacuum chamber is frequently moved up and down with the lance inserted in the vacuum chamber, the core between the lance of the lance device and the lance hole of the canopy of the vacuum chamber is set. The misalignment problem is remarkably improved to reduce the alignment work load, and the relative vertical movement frequency between the lance and the lance hole is reduced to reduce the wear of the sealing device and the lance, and the sealing performance is reliably maintained. Therefore, it is possible to stably secure a high degree of vacuum in the vacuum chamber. Therefore, it is possible to significantly reduce the auxiliary work time, improve the productivity of the vacuum degassing operation, reduce the equipment cost, and stably secure the vacuum degassing operation with a high degree of vacuum.

Further, the vacuum chamber 1 can be divided into a canopy portion 1o and a lower chamber 1u which is easily worn through a flange 26,
The support base 2 is mounted on the canopy 1o via a suspension device (not shown).
Since the lower tank 1u is attached to and detached from the canopy portion 1o, only the lower tank 1u needs to be replaced when replacing the vacuum tank 1, and the lance 8 of the lance device 10 and the vacuum tank 1 are replaced.
Since the alignment between the lance holes 13 of the canopy portion 1o can be omitted, the replacement work load can be significantly reduced, and the productivity of the vacuum degassing operation can be further improved.

The lance device 10 starts and ends the process,
In addition, the height of the vacuum tank must be changed according to the change in vacuum during processing. In order to keep it, it is necessary to constantly change the lance height position.

If the lance device 10 is shown in FIG.
As shown in FIG. 4, when the vacuum tank 1 is mounted on a column 12 that is not integrated with the support frame 2 of the vacuum tank 1 and is fixed by a building 11, for example, the lifting and lowering of the vacuum tank 1 and the lifting and lowering of the lance device 10 are separate mechanisms. Will be controlled by. These raising and lowering controls are extremely complicated and difficult to control, and when the lance 8 is raised and lowered frequently during vacuum degassing, the sealing property of the gap between the lance 8 and the lance hole 13 is significantly deteriorated and the vacuum chamber is evacuated. The degree of vacuum in 1 decreases and stable operation becomes difficult.

However, in the present invention, the lance device 1
0 and the vacuum chamber 1 are fixed in position so that the position of the lance 8 and the central positions of the canopy portion 1o of the vacuum chamber 1 and the lance hole 13 of the sealing device 14 are always aligned with each other.
Since the lance device 10 and the lance device 10 can be simultaneously moved up and down,
Such concerns are resolved.

(Embodiment 2) FIG. 2 is a conceptual diagram of another example of a vacuum evacuation equipment of a tank elevating system in which a lance device for blowing oxygen or fuel gas into the vacuum tank is installed by applying the present invention. It is shown in.

In the vacuum degassing equipment shown here, the position of the ladle 6 is fixed during the operation, and the lower part of the vacuum tank 1 is immersed in the molten steel 5 contained in the ladle 6 to melt the molten steel. The vacuum degassing is performed while flowing between the ladle and the lower part of the vacuum tank. Here, the vacuum tank 1 is supported by a hydraulic cylinder (elevating device) 17 on the support shaft 1 of the support base 15.
A vacuum degassing equipment of a lever-type lifting type is used, which is fixed to a support base 2 which is rotated and raised and lowered about 6 as a fulcrum, and is raised and lowered by a hydraulic cylinder 17 via a support shaft 16 of the support stand 15. Has been done.

In the vacuum degassing equipment of this tank raising / lowering system, since the lance device 10 for blowing oxygen, fuel gas, powder, etc. is installed in the vacuum tank 1, the support frame 2 supporting the vacuum tank 1 is gate-shaped. The support frame 22 is disposed, the column 23 is erected on the support frame, and the lance device 10 is installed on the column. In the lance lifting device 9 of the lance device 10, a lance 8 connected to a supply source (not shown) of oxygen, fuel gas, powder or the like via a supply hose 24 is provided.
The canopy portion 1o and the lance hole 13 of the sealing device 14 are inserted so as to be vertically movable.

In the vacuum degassing operation, the support stand 2 is pivotally raised by the hydraulic cylinder 17 with the support shaft 16 of the support stand 15 serving as a fulcrum, and the vacuum chamber 1 is placed on the ladle 6 carried below. The lance 8 is adjusted by the lance lifting device 10 while retracting to a position where it does not interfere.

Then, after the ladle 6 is carried into the operating position below the vacuum chamber, the support frame 2 is rotated and lowered by the hydraulic cylinder 17 with the support shaft 16 of the support base 15 as the fulcrum, through the counterweight 18. Then, the vacuum chamber 1 is lowered through the support frame, the lower part of the lower chamber 1u is immersed in the molten steel 5 accommodated in the ladle 6 to a predetermined depth, and the lance lifting device 9
Vacuum chamber 1 with the tip position of the lance 8 adjusted by the vacuum degree
The molten steel 5 sucked up and circulated therein is positioned at a predetermined position on the molten metal surface.

Oxygen, fuel gas, powder, etc. are supplied from the supply source via the supply hose 24 at the required timing to the lance 8.
Then, an appropriate amount is blown into the molten steel 5 circulating in the vacuum chamber 1 to carry out the vacuum degassing operation.

In this embodiment, in the vacuum degassing equipment of the chamber elevating type by lever type elevating type, a gate type supporting frame 22 is arranged on the supporting frame 2 for supporting the vacuum chamber 1, and a supporting column is provided on this supporting frame. 23 is provided upright and the lance lifting device 10 is installed on this column.

That is, by disposing the lance device 10 on the support frame 22 provided on the support frame 2 to which the vacuum chamber 1 is fixed, the positional relationship between the lance device 10 and the vacuum chamber 1 is fixed, and the lance 8 is fixed. And lance hole 1 on the canopy 1o of the vacuum chamber 1
The vacuum chamber 1 and the lance device 10 can be moved up and down synchronously with the central position of the vacuum chamber 3 always aligned, and the lance can be inserted into the vacuum chamber even before the vacuum chamber is in the fixed position.

By doing so, the lance device 1
0, the canopy portion 1o of the vacuum chamber 1 and the lance hole 13 of the sealing device 14 are remarkably solved to reduce the positional alignment work load, and the frequency of lifting and lowering the lance 8 is reduced to reduce the sealing device. It is possible to reduce the wear of 14 and reliably maintain the sealing property, and to stably secure the vacuum degree of the vacuum chamber 1. Therefore, it is possible to improve the productivity of the vacuum degassing operation, reduce the equipment cost, and stably secure the vacuum degassing operation.

Further, the vacuum chamber 1 can be divided into a canopy portion 1o and a lower chamber 1u which is easily worn through a flange 26, the canopy portion 1o is fixed to a support base 2, and the lower chamber 1u is fixed to the canopy portion 1o. Since the structure is detachable, only the lower tank 1u needs to be replaced when replacing the vacuum chamber 1, and the lance 8 of the lance device 10 and the lance hole 1 of the canopy 1o of the vacuum chamber 1 are replaced.
Since the alignment between the three can be omitted, the replacement work load can be significantly reduced, and the productivity of the vacuum degassing operation can be further improved.

The lance device 10 starts and ends the process,
Furthermore, the height of the vacuum tank 1 whose height can be changed according to the change of the vacuum degree during processing must be followed up and down, and the distance between the lance up and down-the melt surface is constant against the fluctuation of the melt surface position due to the vacuum degree. In order to maintain the above, it is necessary to constantly change the height position of the lance 8.

Here, if the lance device 10 is attached to a pillar which is not integrated with the support frame 2 of the vacuum chamber 1, for example, a column fixed by a building frame, the vacuum chamber 1 is lifted and the lance device is moved. The raising and lowering of 10 will be controlled by separate mechanisms. In this case, since the ascending / descending trajectory of the vacuum chamber 1 is arcuate, the elevating control of the lance is extremely complicated and difficult, and if the lance is raised / lowered frequently during vacuum degassing, the gap between the lance and the lance hole is increased. The sealing performance of the above is significantly deteriorated, the degree of vacuum in the vacuum chamber is lowered, and stable operation becomes impossible.

However, in the present invention, the lance device 1
0 and the position of the vacuum chamber are fixed, the lance 8 and the vacuum chamber 1
Since the center position of the canopy portion and the central position of the lance hole 13 of the sealing device 14 are always aligned with each other, the vacuum chamber and the lance device can be moved up and down in synchronism with each other.

In the vacuum evacuation equipment of the tank elevating type according to the present invention, there are the following two control methods for carrying out the degassing process without trouble in response to the fluctuation of the molten steel molten metal surface position in the vacuum tank which occurs during operation. . One is constant lance gap control, and the other is constant immersion tube depth control. The former is for controlling the gas jet from the lance so that it is sprayed at the proper pressure on the surface of the molten steel, and the latter is for controlling the dipping pipe to be immersed in the molten steel for a proper distance. is there.

In the constant lance gap control, the decarboxylation efficiency increases as the lance gap decreases when the rate of oxygen transfer is constant. On the other hand, if the lance gap is too small, the molten steel splash will become violent, and the adhesion of the metal to the lance, the inner wall of the vacuum chamber, and the canopy will increase, causing the lance nozzle to melt,
It will lead to serious accidents such as shortened life and water leakage. Therefore, there is an optimum lance gap that takes into consideration operability, facility maintainability, etc., and it is important to control the lance gap so as to satisfy it. However, when the acid transfer rate is changed, the lance gap may be changed accordingly, and the lance gap may be intentionally changed as needed during the degassing process.

Similarly, in the constant control of the depth of the immersion pipe, the immersion pipe sucks the molten steel under a vacuum while being immersed in the molten steel, and the molten metal is exposed to the atmosphere in the pot and the vacuum state in the vacuum tank is obtained. It acts as a partition wall from a certain bath surface. Here, if the atmosphere sometimes invades from the lower end of the dip pipe due to some fluctuation of the molten metal level, the metal will be blown up, leading to a serious accident. Therefore, it is preferable that the partition wall has a maximum immersion depth. On the other hand, if the depth of the dip pipe is too large, the stirring of molten steel in the pot is hindered, and the mixing property of the molten steel in the vacuum tank and the molten steel in the pan outside the vacuum tank deteriorates. Therefore, it is necessary to control the immersion pipe position to the minimum immersion depth required for operation, and constant immersion depth control of the immersion pipe is performed.

In the vacuum degassing equipment of the tank elevating system according to the present invention, degassing treatment is carried out while spraying lance with a lance at a vacuum degree of 160 Torr at the initial stage of operation, and the vacuum degree is raised to 70% from this state.
The following is an example of an operation in which the lance gap is controlled to be constant between the lance and the molten steel surface in the vacuum tank when operated as a Torr.

As an initial condition, the lance gap is 250
0 mm, the difference in molten steel level between the inside of the vacuum tank and the pan was 1200 mm, the immersion depth was 300 mm, and the area ratio of the molten steel level inside the vacuum tank and the molten steel level inside the pan was 1: 2. Due to the change in the degree of vacuum in the vacuum tank, the molten steel in the pan is sucked up into the vacuum tank, and the difference between the molten steel in the vacuum tank and the molten steel in the pan increases from 1200 mm to 1380 mm. Since the ratio of the molten steel level in the vacuum tank to the molten steel level in the pan is 1: 2, the molten steel level in the vacuum chamber rises 120 mm and the molten steel level in the pot drops 60 mm. At this time, the immersion depth of the immersion pipe is reduced by 60 mm and the lance gap is 120 mm.
Decrease. Therefore, in order to correct this, first, the operation of lowering the vacuum chamber to restore the immersion depth of the immersion tube is performed. This means that the dip depth of the dip tube will return to 300 mm by lowering the vacuum chamber by 60 mm. On the other hand, since the lance is installed on the elevating platform of the vacuum chamber, the lance is lowered by 60 mm when the vacuum chamber is lowered. Therefore, the lance gap has decreased by 180 mm from the beginning, so the lance is raised 180 mm and the lance gap is returned to 2500 mm to continue the operation.

By performing these operations promptly by computer control, the lance gap is kept constant while keeping the immersion depth of the immersion pipe in the molten steel in the pan constant with the change in the degree of vacuum in accordance with the change in the degree of vacuum. Can be held at.

Further, in the present invention, the lance may be moved up and down in synchronism with the vacuum chamber lifting type vacuum chamber, so that the airtightness of the lance in the lance hole of the vacuum chamber is more strict than that of the conventional pot lifting system. There is a need to do. As an example,
For example, a ring-shaped fire-resistant rubber tube or the like is attached around the lance hole, and the tube is pressurized and released to obtain higher airtightness. That is, the tube is sealed by being brought into close contact with the lance in a pressurized state, and when moving the lance, the pressure is released to release the close contact state between the tube and the lance. Further, by further disposing the lance device on the support frame of the vacuum degassing equipment and adopting the sealing method, the sealing property of the lance hole is significantly improved.

Here, an example of the operation flow of the sealing device based on the constant lance gap control when the lance is installed on the lifting platform is shown below. Vacuum level change → Vacuum chamber up / down → Seal tube removal pressure → Lance up / down → Seal tube pressurization

The present invention can be easily applied to a vacuum degassing equipment of a tank raising / lowering system by a winch raising / lowering system as shown in FIG. 6, and a support (or a supporting frame or the like) is provided on the support base 2. However, by disposing the lance device here, it is possible to obtain the same effect as in the first and second embodiments.

Further, in the first and second embodiments, the position of the lance device is arranged so as to move vertically from the upper part of the vacuum chamber. It can be changed within the range satisfying the claims such that it is inserted obliquely from the upper part of the chamber into the vacuum chamber or obliquely inserted from the side wall surface of the upper part of the vacuum chamber.

Furthermore, the present invention is not limited to the above-mentioned first and second embodiments, and the structure of the vacuum chamber and its supporting structure, the lance device and its supporting structure, the elevating structure, the exchanging structure, etc. Layout, processing content, equipment type, lifting method, vacuum tank and ladle replacement method,
The constituent conditions are changed within the scope of satisfying the claims according to the conditions such as the operation system.

(Operation example) Killed steel is treated in the vacuum degassing equipment of the tank raising / lowering method of the present invention shown in FIGS. 1 and 2 and the conventional vacuum degassing equipment of the ladle raising / lowering method shown in FIG. Vacuum degassing operation was carried out as a target. As a result, in the case of the conventional example, the ultimate vacuum is 0.8 to 1.6 To.
While it was in the range of rr, in the case of the present invention, the ultimate vacuum showed a high value of 0.5 to 0.1 Torr, which was a good influence on the degassing performance.

Further, when the life of the sealing device is expressed by the number of heat when the ultimate vacuum degree in the vacuum chamber falls below the allowable range by continuously performing the vacuum degassing operation, in the case of the conventional example, While the life of the sealing device was around 130 heats, in the case of the present invention, the life of the sealing device was around 320 heats, which also contributed to the reduction of the maintenance cost of the sealing device.

In the case of the present invention, the good results as described above were obtained because the lance hole and the lance are always aligned with each other and no unreasonable force was applied to the sealing device. This is because the wear was suppressed and the sealing property was secured for a long time. Further, the alignment time between the lance hole of the vacuum chamber and the lance hole of the sealing device and the lance of the lance device is 1.5 in the case of the conventional example.
Although it took time, in the case of the present invention, the upper tank including the canopy portion of the vacuum tank is supported by the support frame,
Since only the lower tank was replaced, it was almost unnecessary to align the lance hole of the vacuum tank with the lance hole of the sealing device and the lance of the lance device.

[0057]

EFFECTS OF THE INVENTION In the vacuum evacuation treatment equipment of the tank elevating system of the present invention, a lance device (lance and its elevating device) for blowing oxygen, fuel gas powder and the like into the vacuum tank.
Since it was moved up and down at the same time as the vacuum chamber, the positional deviation between the lance of the lance device and the lance hole of the canopy of the vacuum chamber,
Problems such as wear of the seal device can be remarkably improved, wear of the seal device is reduced, and sealing performance is ensured.
It is possible to secure a sufficient degree of vacuum in the vacuum chamber.

As a result, conventionally, there has been a problem of misalignment between the lance of the lance device and the lance hole of the canopy portion of the vacuum chamber, or the wear of the sealing device, and the operation of blowing oxygen, powder or fuel gas into the vacuum chamber. It is possible to use the lance device of the present invention even in the vacuum degassing treatment equipment of the tank elevating system, which was difficult to do, and further, at any time from before the lower part of the vacuum tank is immersed in the molten steel until after the treatment is completed. It is possible to put it in and out of the vacuum tank, and it is possible to realize a vacuum degassing operation with excellent operation efficiency. Also,
It is possible to extend the life of the sealing device between the lance of the lance device and the lance hole of the canopy of the vacuum chamber, improve the maintainability of the equipment, reduce the equipment cost, and improve the productivity of the vacuum degassing operation. is there.

If the vacuum tank can be divided into a canopy portion and a lower tank that is easily worn, the canopy portion is fixed to the support frame, and the lower tank is detachable from the canopy portion, the vacuum tank can be replaced. In this case, only the lower tank needs to be replaced, and the alignment between the lance of the lance device and the lance hole of the canopy of the vacuum tank can be omitted, so the replacement work load can be further reduced and the production of the vacuum degassing operation can be reduced. It is possible to further improve the property.

[Brief description of the drawings]

FIG. 1 is a side cross-sectional conceptual explanatory diagram of an example of a tank elevating type vacuum degassing equipment in an embodiment of the present invention.

FIG. 2 is a side cross-sectional conceptual explanatory view of an example of a tank elevating type vacuum degassing equipment in another embodiment of the present invention.

FIG. 3 is a side cross-sectional conceptual explanatory view of an example of a well-known tank fixing system (ladle lifting system) vacuum degassing equipment.

FIG. 4 is a side cross-sectional conceptual explanatory diagram of an example of a vacuum degassing equipment of a well-known lever type tank elevating system.

FIG. 5 is a side cross-sectional conceptual explanatory view of an example of a well-known vacuum column degassing equipment of a 4-column cylinder type, which is used for raising and lowering a tank.

FIG. 6 is a side cross-sectional conceptual explanatory view of an example of a well-known winch elevating and elevating tank elevating and lowering vacuum degassing facility.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum tank 1o Canopy part 1u Lower part 2 Support stand 3 Lifting device 4 Lifting table 5 Molten steel 6 Ladle 7 Immersion pipe 8 Lance 9 Lance lifting device 10 Lance device 11 Building 12 Pillar 13 Lance hole 14 Sealing device 15 Support stand 16 Support shaft 17 Lifting device 18 Counterweight 19 Supporting column 20 Winch 21 Chain 22 Supporting frame 23 Supporting column 24 Supply hose 25 Exhaust gas duct 26 Flange cb Arc-shaped lifting trajectory

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hikofumi Taniishi 46-59 Nakahara, Tobata-ku, Kitakyushu City, Fukuoka Prefecture Nippon Steel Corporation Machinery & Plant Division

Claims (4)

[Claims] 1. In a vacuum degassing equipment of a tank elevating type,
A vacuum for a tank raising / lowering method, characterized in that a lance device supporting a lance for injecting oxygen, fuel gas, powder, etc. into a vacuum tank so as to be able to move up and down is directly disposed in the vacuum degassing equipment for the tank raising / lowering method. Degassing equipment. 2. In a vacuum degassing equipment of a tank elevating type,
The lower part supports the vacuum tank immersed in the molten metal contained in the ladle, and the supporting frame is arranged on the supporting frame that is moved up and down by the lifting device. Oxygen, fuel gas, powder, etc. are placed in the vacuum tank on this supporting frame. A vacuum degassing treatment facility of a tank raising and lowering system, in which a lance device supporting a lance for blowing air is provided so that the lance device can be raised and lowered simultaneously with the vacuum chamber. 3. The vacuum chamber is divided into a canopy portion fixed to a support frame and a lower chamber, the canopy part is fixed to the support frame, and the lower part is made attachable to and detachable from the canopy part. Item 1. A vacuum degassing treatment facility of the vessel lifting type according to Item 1. 4. The vacuum degassing equipment is an RH type vacuum degassing equipment.
The vacuum degassing equipment of the tank lifting method described in the item.