JP2724087B2 - Explosion-proof gas bushing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reduces the amount of gas contributing to the explosion of an insulator when the insulator is exploded by partitioning the interior of the insulator filled with an insulating gas with an insulating cylinder, thereby suppressing the scattering of fragments. It is related to explosion-proof gas bushings.

[0002]

2. Description of the Related Art As shown in FIG. 3, an insulating tube 2 made of FRP or the like is mounted inside a porcelain tube 1 filled with an insulating gas. Partitioned gas proof bushings are known in the art. In such an explosion-proof gas bushing, the inner space 3 and the outer space 4 are communicated with each other by gas passages 5 and 6 formed near the upper and lower ends of the insulating cylinder 2. Are equal.

[0003] In such an explosion-proof gas bushing, even if the insulator tube 1 is broken by a flying object or the like, the gas in the outer space 4 mainly contributes to the explosion, and the inner gas occupies most of the gas space. Since the gas in the space 3 cannot suddenly flow out, it is possible to suppress the debris from scattering. In this case, as the gap between the insulator tube 1 and the insulating tube 2 is made as narrow as possible, and the gas passages 5 and 6 are made narrower, a higher debris scattering suppression effect can be obtained. This type of explosion-proof gas bushing has the advantage of high long-term reliability because the structure is simple, the number of parts is small, and there are few elements that cause a failure.

By the way, inside the insulating cylinder 2 of this type of explosion-proof gas bushing, gas convection occurs as shown by an arrow in FIG. 3 and heat generated by the central conductor 7 is radiated. Heat is transmitted through many heat insulating layers such as the central conductor 7 → the inner space 3 → the insulating tube 2 → the outer space 4 → the insulator tube 1;
Since the diameter of the upper part is narrowed, convection is suppressed, and there is a problem that heat is easily trapped. Further, in the explosion-proof gas bushing of this type, when the insulator tube 1 is broken, the gas in the inner space 3 moves to the outer space 4 through the upper and lower gas passages 5 and 6 and contributes to the scattering of debris at all. When the porcelain tube 1 is broken, the insulating gas inside the porcelain tube gradually leaks through the gas passages 5 and 6, so that there is a problem that the power cannot be supplied.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems, is excellent in heat radiation effect and debris scattering suppression effect, and prevents leakage of insulating gas inside the insulator tube even when the insulator tube is broken. It has been completed to provide a new explosion-proof gas bushing that can be used.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. According to the present invention, the inner gas space of the insulator tube is divided into two parts by an insulating tube inserted inside the insulator tube. There the explosion-proof gas bushing forms communicate with each other above and below the gas passage of the insulating tube, the upper end of the ceramic tube
Provide a sealed radiator and attach a
Compression spring is fixed between the flange and the top of the radiator.
And heat radiation facing the lower surface of the flange-shaped projection
The upper gas passage is closed when the insulator tube is broken on the upper surface of the bottom plate of the vessel
Gasket to secure the lower end of the insulator tube
On the underside of the attachment flange, a lower gas passage
A gasket for closing is provided .

[0007]

In the explosion-proof gas bushing of the present invention, the upper and lower gas passages are immediately closed by members moving upward by gas pressure when the insulator tube is broken, so that the gas in the inner space moves to the outer space when the insulator tube is broken. Thus, there is no possibility of contributing to the scattering of fragments, and the effect of suppressing fragment scattering can be enhanced. Also, since the upper and lower gas passages are immediately closed,
Leakage of the insulating gas inside the insulator tube can be prevented.
Further, for this reason, in the explosion-proof gas bushing of the present invention, the gas passages can be made wider than before, so that convection circulating between the inner space and the outer space can be generated through these gas passages, and the upper part of the bushing can be formed. Heat can be prevented from being trapped.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the embodiments shown in FIGS. In FIG. 1, 1 is a porcelain pipe, 2
Is an insulating tube made of FRP inside the insulator tube 1, 3 is an inner space of the insulating tube 2, and 4 is an outer space of the insulating tube 2. A lower end of the insulator tube 1 is fixed on a mounting flange 8, a cylindrical radiator 9 is fixed on an upper portion of the insulator tube 1, and a ceiling plate 10 is fixed on an upper surface of the radiator 9. The center conductor 7 hangs from the lower surface of the ceiling plate 10, and the lower end of the center conductor 7 is supported by a tulip contact 11 so as to be slidable in the vertical direction.

A lower support 12 is attached to the lower surface of the mounting flange 8 with a predetermined gap provided therebetween.
Is placed on the lower support 12. A lower gas passage 13 is provided through the lower support 12. The outer diameter of the flange at the lower end of the insulating cylinder 2 is set to be larger than the inner diameter of the mounting flange 8, and a gasket 14 is mounted on the lower surface of the mounting flange 8.

On the other hand, a flange-like projection is provided on the upper end of the insulating cylinder 2.
15 is fixed, and a compression spring 16 is provided between the upper surface and the lower surface of the ceiling plate 10. For this reason, the insulating cylinder 2 is repelled downward by the force of the compression spring 16, and the lower end thereof is pressed against the upper surface of the lower support 12 to be fixed. The lower surface of the flange-like projection 15 is separated from the upper surface of the bottom plate 9a of the radiator 9 by a predetermined distance, and a gasket 17 is provided on the upper surface of the flange-like projection 15 in this portion.
An upper gas passage 18 is formed between the center hole formed in the bottom plate 9a and the upper end of the insulating cylinder 2. The lower gas passage 13 and the upper gas passage 18 are sufficiently wider than the conventional gas passages 5 and 6 shown in FIG.

Next, the function of the explosion-proof gas bushing having the above configuration will be described. First, in this explosion-proof gas bushing, since the lower gas passage 13 and the upper gas passage 18 are widened, gas flows easily occur, and heat generated in the central conductor 7 by energization as shown by an arrow in FIG. Convection occurs. This convection is different from the convection of FIG.
And the outer space 4 is circulated in one direction, and is performed extremely smoothly. Therefore, the flow velocity of the convection is increased, and the heat generated in the central conductor 7 can be transmitted to the insulator tube 1 and the radiator 9 by flying through the insulating tube 2, so that the heat resistance is small and high heat dissipation can be obtained. Therefore, heat does not stay in the upper portion of the bushing.

When the insulator tube 1 of the explosion-proof gas bushing is broken, the pressure in the outer space 4 becomes zero as shown in FIG. 2, so that the pressure in the inner space 3 is P (kgf / cm ² -G). , P is the insulation tube _{^{2 (D 2 2 -D 1 2}} ) π / 4 is exerted upwardly. Then, the mass M ₁ of the insulating cylinder 2 is changed to P (D ₂ ²
Once you have less than -D ₁ ²⁾ π / 4, the insulating tube 2 is moved upward. Since the outer diameter of the flange at the lower end of the insulating cylinder 2 is larger than the inner diameter of the mounting flange 8 as described above, the flange at the lower end of the insulating cylinder 2 closely contacts the gasket 14 on the lower surface of the mounting flange 8 as shown in FIG. To close the lower gas passage 13.

The radiator 9 has P [(D ₄ ² −D ₃ ² ) π /
4] acts upward, the mass M _{2 of} this portion
Is smaller than this, the radiator 9 is lifted up by the pressure of the gas. Since the diameter of the flange-like projections 15 described above is greater than the center hole inner diameter D ₃ of which is formed in the bottom plate 9a, a bottom plate 9a of the radiator 9 collides with the lower surface of the flange-like projections 15, gas gasket 17 and the upper passageway Block 18

When the porcelain tube 1 is broken in this way, the upper gas passage 18 and the lower gas passage 13 are immediately closed by a member that moves upward by gas pressure. Therefore, the supply of gas from the inner space 3 to the outer space 4 is shut off, and the gas in the inner space 3 is prevented from contributing to the scattering of debris. Therefore, the explosion-proof gas bushing of the present invention can obtain a more excellent debris scattering suppression effect than the conventional type shown in FIG. Furthermore, if the gaskets 14 and 17 completely seal the gas passages 13 and 18 as in the embodiment, there is no danger that the internal gas pressure decreases and the internal insulation strength is maintained as it was before the explosion. . In addition, since the external insulation can be temporarily endured by the insulating tube 2, the operation can be performed as it is for the time being, and there is an advantage that it is possible to increase the time for taking measures against accidents.

[0015]

As described above, the explosion-proof gas bushing of the present invention has excellent heat radiation characteristics because it can smoothly convect gas under normal conditions, and shuts off gas supply from the inner space when the insulator tube is broken. As a result, there is an advantage that the operation can be continued for the time being even after the porcelain tube is broken, while the effect of suppressing the fragment scattering is enhanced.

[Brief description of the drawings]

FIG. 1 is a central longitudinal sectional view showing an explosion-proof gas bushing according to an embodiment of the present invention.

FIG. 2 is a central vertical sectional view showing a state at the moment when an explosion-proof gas bushing according to an embodiment of the present invention is broken.

FIG. 3 is a central longitudinal sectional view showing a conventional explosion-proof gas bushing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulator tube 2 Insulation cylinder 3 Inner space 4 Outer space 13 Lower gas passage 18 Upper gas passage

Claims (1)

(57) [Claims] An explosion-proof gas in a form in which an inner gas space of an insulator tube is partitioned into two parts by an insulating tube inserted inside the insulator tube, and these two spaces communicate with each other through gas passages above and below the insulating tube. In the bushing, it is sealed at the upper end of the insulator tube.
Radiator, and a flange at the upper end of the insulation tube
Fix the projection and provide a compression spring between the top of the radiator and
Also, the bottom plate of the radiator facing the lower surface of this flange-shaped projection
Gas that blocks the upper gas passage when the insulator tube breaks
Install a bracket and fix the lower end of the insulator tube.
Close the lower gas passage on the underside of the flange when the insulator tube is broken
Explosion-proof gas bushing with gasket .