JP2567145Y2 - Upper sealing device for lower charging induction heating furnace - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a gap between an anti-tilt body and a through-hole provided in a furnace ceiling wall in a lower charging induction heating furnace for shielding the inside of a furnace from outside air and controlling a furnace atmosphere. The present invention relates to an upper sealing device for sealing a seal.

[0002]

2. Description of the Related Art Generally, in a lower charging type heating apparatus for loading and unloading an object to be heated such as a billet from a furnace bottom of a furnace body, a device for preventing the charged object to be heated from tilting. Is attached. FIG. 5 and FIG.
The means disclosed in JP-A-63-166933 is shown below. 5 is a vertical cross-sectional view in the thickness direction of the object to be heated, FIG. 6 is a vertical cross-sectional view taken along the line II of FIG.
Reference numeral 5 denotes an elevating table, and reference numeral 6 denotes a steel slab as an object to be heated.

The furnace body 1 is surrounded by a side wall having an induction coil 2 buried on the inner surface, and a lower part is provided with an opening 3 through which a billet 6 is inserted and drawn out, and an upper part shown in FIG. As can be seen, holes 4 penetrating the ceiling wall 1a upward and downward at a plurality of locations in the longitudinal direction are opened, and the tilting prevention body 10 has its lower end faced into the furnace main body 1 through each of the through holes 4. It is arranged in.

[0004] Each tilt preventing body 10 has a length close to the upper and lower heights of the furnace main body 1 and is formed in a rod-like shape having a cylindrical shape having a diameter equal to or smaller than the thickness of the billet 6. A cooling water passage (not shown) is formed inside. Each tilt prevention body 10
Is a portal-shaped support rod 12 with its middle part straddling the furnace body 1.
Lifting guide 12 provided on the upper and lower double horizontal beams 12b, 12b
c and 12c, the upper end of which is pivotally connected to one end of a connecting rod 11b fixed to a rod 11a of a hydraulic cylinder 11 serving as an elevating drive means so as to make a right angle with the connecting rod 11b.
Through the through hole 4 formed in the ceiling wall 1a of the furnace 1 so as to face the inside of the furnace main body 1 and to be moved up and down in the furnace main body 1 by the operation of the hydraulic cylinder 11 along the lifting and lowering area of the steel slab 6. Has become.

[0005] The portal-type support frame 12 is constructed by providing upper and lower double horizontal beams 12b, 12b at the upper ends of the columns 12a, 12a. Elevating guides 12c, 12c are provided substantially at the center, and a middle part of the hydraulic cylinder 11 is pivotally supported by a support 11c on the outer surface of the support 12a. Each hydraulic cylinder 11 is configured to be able to operate simultaneously or individually by a hydraulic control unit (not shown).

In the conventional apparatus constructed as described above, each of the hydraulic cylinders 11 is actuated in advance to prevent the tilt preventing body 10 from moving.
Of the furnace body 1 so as to be positioned near the entrance 3 of the furnace body 1. Now, when the steel slab 6 is placed on the elevating platform 5 and the elevating platform 5 is lifted, the tilting prevention member is waiting at the position where the upper end of the steel slab 6 enters the entrance 3 of the furnace body 1. It hits the lower end of 10. When the lower end of the anti-tilt body 10 comes into contact with the upper surface of the steel slab 6 at a required pressure, the hydraulic cylinder 11 moves its rod at the same speed as the lift of the lift 5 while maintaining the pressed state.
Advance 11a.

As a result, the steel slab 6 is pressed from above and below by the elevating platform 5 and the tilt preventing body 10, and is inserted into the furnace main body 1 without tilting. However, it is necessary to control the atmosphere inside the furnace body 1 to a low O ₂ concentration in order to prevent the steel slab 6 from being oxidized during heating, and the through holes 4 vertically penetrate the ceiling wall 1 a of the furnace body 1. It is necessary to block and seal the outside air and atmospheric gas 13, and the ceiling wall 1
A pair of sealing devices 14a is disposed above the through hole 4 provided in the device a. The conventional sealing device 14a will be described below with reference to FIGS. In the figure, reference numeral 10 denotes an anti-tilt body. As described above, the anti-tilt body 10 is structured to be supported by the elevating guide 12c from all directions when ascending and descending, as shown in FIG. In addition, it comprises a portion where the guide rails 15 are attached to the four surfaces of the tilt prevention body 10, a portion covered with a castable (refractory material) 16 to be exposed inside the furnace main body 1, and a tip metal member 23 a.

As shown in FIGS. 7 and 8, a conventional sealing device 14a includes a semi-circular sealing frame 17a having a ceramic fiber sealing material 18 attached inside a sealing member 17 via a link mechanism 19. The frame 17b of the sealing device 14a is also pressed by the two air cylinders 20a against the castable portion 16 or the guide rail portion 15 of the tilt prevention body 10 and at the same time the cylindrical sealing material 22 fixed to the ceiling wall 21 of the furnace body 1. By pressing, the outside air and the atmosphere in the furnace were shut off.

[0009]

[Problems to be Solved by the Invention] Conventional sealing device 14a
Then, there were the following problems. Anti-tilt body for ceramic fiber, which is the sealing material 18.
In the case where the castable is pressed directly against the castable portion of Case 10 (Case 1), a gap is formed between the castable and the ceramic fiber when the surface of the castable is not a clean circle and when the ceramic fiber loses its elastic restorability due to deterioration with time. Sealability is impaired. Also, when pressing against the guide rail portion (case 2), the guide rail portion is not arc-shaped, so it cannot be matched with the shape on the sealing material side,
The sealing property cannot be secured.

The ceramic fiber as a sealing material is directly exposed to a high-temperature atmosphere in the furnace and easily deteriorates with time due to heat, and the slab upper edge support device is pushed up by the thermal expansion of the slab, and the ceramic fiber is castably rubbed. As a result, the surface is roughened, and the sealing material falls off at an early stage, and the sealing performance is impaired. Since the semi-circular frame 17a of the sealing device 14a for opening and closing by the single air cylinder 20 by the link mechanism, can not be increased in size in S _1, S ₂ parts shown in FIG. 8, the tilt prevention body
10 and the sealing material (ceramic fiber 18) come in contact and easily fall off. To open and close with the link mechanism 19, the sealing device 14
Sealing material 18 (ceramic fiber) even when a is open
The space for replacing is small, and the maintainability is extremely poor.

The semicircular frame 17 of the sealing device 14a
Since a is opened and closed by the link mechanism 19 by one air cylinder 20, if one of the frames 17a hits against the tilt-preventing body 10, the other may not be sufficiently pressed. It has the disadvantage of being impaired. SUMMARY OF THE INVENTION It is an object of the present invention to provide an upper sealing device of a lower charging type induction heating furnace which can solve the problems of the prior art.

[0012]

In order to achieve the above object, according to the present invention, an anti-tilt body is slidably moved up and down through a through hole provided in a ceiling wall of a furnace body, and the furnace body is inserted into the furnace body from a lower entrance. In the upper sealing device of the lower charging induction heating furnace configured to prevent the object to be heated from tilting on the lift table, only the seal corresponding portion of the tilt preventing body is a cylindrical metal member, while the seal portion frame is provided. Is divided in the circumferential direction into two semicircular arcs, each semicircular seal part frame can be opened and closed independently with respect to the cylindrical hardware of the tilt preventing body, and each semicircular seal part frame A semi-annular sealing material to be brought into contact with the cylindrical metal member is arranged on the inner peripheral surface of
A lower portion provided with a blow port for injecting a furnace atmosphere gas between the two-stage semi-annular seal members and / or between the semi-annular seal members and the lower end of the semi-circular seal portion frame; It is an upper sealing device of a charge type induction heating furnace.

[0013]

According to the present invention having the above-described structure, the following effects can be obtained. The anti-tilt body is provided with a cylindrical metal only at a portion where the seal material attached to the seal portion frame is pressed, so that the flatness between the seals is ensured to improve the sealability.

If the position where the sealing material attached to the sealing portion is pressed against the cylindrical metal member is located above, the distance from the high-temperature atmosphere in the furnace can be increased to prevent deterioration due to the influence of heat. By changing the opening / closing mechanism of the sealing device from a conventional link mechanism using one air cylinder to an independent opening / closing type using two air cylinders, it is possible to prevent poor sealing performance due to one end of the sealing frame in an arc shape, and to provide a seal. Since the opening / closing amount of the unit frame can be increased, the maintainability is also improved.

In order to further improve the sealing property, the sealing material is attached to the upper part and the lower part in two parallel stages and the inside of the furnace is purged with the atmosphere gas, so that the sealing property can be improved.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 4, only the seal-corresponding portion of the tilt-preventing body 10 is formed as a cylindrical metal member 24 (see FIG. 4C) to secure the flatness of the sealing surface and improve the sealing performance. In addition,
The portion where the tilt-preventing body 10 below the cylindrical hardware 24 is inserted into the furnace comprises a castable portion 16 (see FIG. 4 (d)) and a tip hardware 23 as usual, and the upper part of the cylindrical hardware 24 is a guide. The rail 15 is provided, and the guide rail 12 is guided by a guide roller 12a provided on the gate-shaped support frame 12 to move up and down as in the conventional case.

On the other hand, as shown in FIGS. 1 to 3, the upper sealing device 14 is arranged in a pair near the elevating guide 12c above the ceiling wall 1a, and the sealing portion frame of the sealing device 14 is divided into two parts in the circumferential direction. A semi-annular sealing material (for example, ceramic fiber having heat-insulating sealing properties) 18 is attached to the inner peripheral surface of each of the opposing semi-circular sealing section frames 17 in two upper and lower stages. In the drawings, only the right side is shown, and the left side is omitted. The furnace atmosphere gas inlet 25 is connected to a pipe 29a fixed by welding by being incorporated into the semicircular seal frame 17.
The atmosphere gas in the furnace for preventing oxidation is blown from a. It is effective to arrange the blowing port 25a in the middle of the upper and lower two-stage semi-annular sealing members 28 in order to improve the sealing performance.

The semicircular seal portion frame 17 is connected to the frame main body 27 using bolts 30.
Are provided with a plurality of rollers 28, and the frame body 27 is moved by the rotation of the rollers 28. The roller 28 may have a structure using a sliding plate or the like as another method. And body frame
27 is guided by a horizontal guide beam 31 supported by a support frame 32 via a roller 28 so that it can move forward and backward, and is attached to the horizontal guide beam 31 via a pin portion 26 on the main body frame 27. It is connected to the air cylinder 20.

On the other hand, although the lower end of the semicircular seal portion frame 17 is pressed against the seal member 22 attached to the pipe seat 21 provided on the ceiling wall 1a to seal the same, it is almost the same as the conventional one.
It is preferable to blow in-furnace atmosphere gas for preventing oxidation from the in-furnace atmosphere gas inlet 25b communicating with the pipe 29b fixed to the seal portion frame 17 from the viewpoint of improving sealing performance.

Next, the operation of the present invention will be described. The sealing device 14 is sufficiently separated from the tilt preventing body 10 to secure a space between the sealing device 18 when the tilt preventing body 10 is moved up and down. Then, each hydraulic cylinder 11 is actuated in advance so that the lower end of the tilt prevention body 10 is on standby so that the lower end of the tilt prevention body 10 is located near the entrance 3 of the furnace body 1, while the steel slab 6 is placed on the elevator 5, and the elevator 5 is raised. Then, at the position where the upper end of the billet 6 enters the entrance 3 of the furnace body 1,
It hits the lower end of 10. When the lower end of the tilt preventing body 10 abuts on the upper surface of the steel slab 6 at a required pressure, the hydraulic cylinder 11 advances the rod 11a at the same speed as the lift of the elevator 5 while maintaining the pressed state. As a result, the steel slab 6 is pressed from above and below by the elevating platform 5 and the tilt preventing body 10, and is inserted into the furnace main body 1 without tilting.

When the billet 6 is inserted into the furnace main body 1, the cylindrical metal piece 24 of the tilt prevention body 10 is positioned at a position corresponding to the position of the sealing device 14 disposed above the ceiling wall 1a of the furnace main body 1. Become.
Therefore, when the air cylinders 20 are operated independently of each other in the extending direction to advance the semicircular seal portion frame 17 located at a position away from the tilt prevention body 10, the main body frame 27 is horizontally guided by the rollers 28. It moves forward while being guided by the frame 31.

As a result, the two upper and lower seal members 18 attached to the inner peripheral surface of the semicircular seal portion frame 17 integrally connected to the horizontal guide beam 31 are perpendicular to the cylindrical metal member 20 of the tilt prevention body 10. At the same time, the lower end of the seal portion frame 17 is vertically pressed with a suitable pressure to a sealing material 22 attached to a ceiling wall pipe seat 21 provided on the ceiling wall 1a of the furnace body 1. Pressing at this time is performed independently for the left and right, so that the pressing can be performed smoothly without applying excessive force. Subsequently, by blowing in-furnace atmosphere gas for preventing oxidation from the gas injection ports 25a and 25b, a suitable seal is achieved.

The sealing device having the above-mentioned structure is connected to an existing lower charging type induction heating furnace, a furnace length of 13 m, an applicable slab size of 12 m × thickness of 220 mm × width of 1500 mm, a furnace temperature of 1350 ° C., and a furnace atmosphere gas N _2. As a result of being applied to a total of three seal portions of the through hole of the tilt prevention body used, it is possible to prevent gas in the furnace from being blown out at the seal portion while the slab is being heated and air from being blown out of the furnace. The oxygen (O ₂ ) concentration in the internal atmosphere was conventionally 3000 to 5000 ppm, but it could be reduced to about 500 ppm, and sufficient sealing properties could be secured.

[0024]

According to the present invention, as described above, the following effects can be obtained. The heat insulating material of the sealing device is divided into two parts in the circumferential direction of the tilt-preventing body, and each can be independently opened and closed by a separate air cylinder. Can be sufficiently secured, and breakage and falling off of the heat insulating material due to contact between the two can be prevented.

By controlling the sealing portion of the tilt-preventing body as a cylindrical metal having a flat surface and maintaining good sealing performance with the sealing material over a long period of time, the oxygen (O ₂ ) concentration in the furnace can be controlled to a low level. Can reduce the scale loss due to oxidization of the slab surface and improve the yield.It can prevent the low-melting oxide scale from melting and stopping the deterioration of the furnace wall and hearth metal fittings. When the N ₂ gas purge amount increased, the atmosphere temperature decreased, the gas temperature decreased, and the N ₂ gas was purged into the furnace to increase the furnace pressure to maintain the O ₂ concentration at a low level. The slab temperature locally decreased near the discharge port, resulting in uneven heating, which reduced the quality and yield. However, these can be prevented at once by improving the sealing performance itself.

[Brief description of the drawings]

FIG. 1 is a side view showing the device of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a partially enlarged side view showing a part a of FIG. 1;

4A is a side view showing the structure of the tilt preventing body of the present invention, FIG. 4B is a view taken along the line AA of FIG. 4A, and FIG.
FIG. 3 is a cross-sectional view taken along the line BB.

FIG. 5 is a vertical cross-sectional view in the thickness direction of an object to be heated, showing conventional lower-mount heating.

FIG. 6 is a vertical sectional view taken along the line II of FIG. 5;

FIG. 7 is a side view showing a conventional device.

FIG. 8 is a plan view of FIG. 7;

9A is a side view showing a conventional tilt-preventing body structure, FIG. 9B is a view taken along the line AA of FIG. 9A, and FIG.
It is sectional drawing which shows -B arrow.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace main body 2 Induction heating coil 3 Doorway 4 Anti-tilt through hole 5 Elevating stand 6 Steel piece 10 Anti-tilt body 11 Hydraulic cylinder 12 Gate type support frame 12c Elevating guide 13 Atmospheric gas 14 Sealing device 15 Guide rail 16 Castable 17 Seal part Frame 18 Sealing device side sealing material 19 Link 20 Air cylinder 21 Ceiling wall pipe seat 22 Ceiling side sealing material 23 Tip metal 24 Cylindrical metal 25 Furnace atmosphere gas inlet 26 Pin 27 Body frame 28 Roller 29 Piping 30 Bolt 31 Horizontal Guide beam 32 support frame

Claims (1)

(57) [Scope of request for utility model registration] A tilt prevention body is slidably moved up and down through a through hole provided in a ceiling wall of a furnace main body to prevent the object to be heated from being tilted on an elevating table inserted into the furnace main body from a lower entrance. In the upper sealing device of the lower charging induction heating furnace, only the seal corresponding portion of the tilting prevention body is a cylindrical metal member, and the seal portion frame is divided into two in the circumferential direction to have a semicircular shape. The semi-circular seal portion frame can be opened and closed independently with respect to the cylindrical hardware of the tilt preventing body, and the semi-circular shape is brought into contact with the cylindrical hardware on the inner peripheral surface of each semi-circular seal portion frame. An annular sealing material is attached in parallel in two upper and lower stages, and between the two stages of semi-annular sealing materials and / or
Alternatively, an upper sealing device for a lower charging type induction heating furnace, characterized in that a blow port for blowing in-furnace atmosphere gas is provided between the semi-annular sealing material and a lower end of the semi-circular sealing portion frame.