US3629661A

US3629661A - Metal clad switchgear for high voltage comprising compartments adapted to be divided by movable transverse partition walls

Info

Publication number: US3629661A
Application number: US76749A
Authority: US
Inventors: Egbertus Adrianus Frowein
Original assignee: COQ NV
Current assignee: COQ NV
Priority date: 1970-09-30
Filing date: 1970-09-30
Publication date: 1971-12-21
Anticipated expiration: 1988-12-21

Abstract

In metal clad switchgear the provision of slide valves to divide compartments in two parts which are separated from one another in a gastight manner, when said slide valves are in their closed position, said slide valves being held against movement in a direction at right angles to their plane by guides and cooperating with axially movable, coaxial sealing rings which are supported by the envelope of said compartments and forced against said slide valves by springs.

Description

7 United States Patent [72] Inventor Egbertus Adrlanus Froweln Arnhem, Netherlands [2 1] Appl. No. 76,749

[22] Filed Sept. 30, I970 [45] Patented Dec. 21, 1971 [73] Assignee N.V. COQ,

Utrecht, Netherlands [54] METAL CLAD SWITCI'IGEAR FOR HIGH VOLTAGE COMPRISING COMPARTMENTS ADAPTEI) TO BE DIVIDED BY MOVABLE TRANSVERSE PARTITION WALLS 5 Claims, 4 Drawing Figs.

[52] U.S.CI 317/103, 200/148 B [5 I Int. Cl H0111 33/82 [50] Field of Search 200/148 B,

[56] References Cited UNITED STATES PATENTS 3,367,625 2/1968 Fortune 251/328 X 3,564,344 2/1971 Boersma 317/103 FOREIGN PATENTS 6,71 1,574 2/1969 Netherlands 200/148 R Primary Examiner-Lewis 1-1. Myers Assistant Examiner-Gerald P. Tolin Attorney-Snyder & Butrum II 3 a 4, 1 1 a 203 m I 233 lTiTI 1 ill i J82 J l J 1 k 1 3% $32 55 i2 23 T v 5 2 2b \i 3b Vi PATENTED 05221 I971 3629166 1v SHEET 1 BF 2 ZNVENTOR PATENTED M021 IQTI SHEET 2 OF 2 IN VENTOR METAL CLAD SWITCI'IGEAR FOR HIGH VOLTAGE COMPRISING COMPARTMEN'IS ADAPTED TO BE DIVIDED BY MOVABLE TRANSVERSE PARTITION WALLS The invention relates to metal-clad switchgear for high voltage comprising a gas-filled metal envelope, which is intended to be connected with earth and divided into a number of compartments, of which at least one compartment is divided into two parts interconnected by a chamber containing a transverse partition wall which is adapted to be moved in its plane and to separate said compartment parts from one another and from said chamber in an airtight manner.

Metal clad switchgear of this kind is disclosed in the Dutch Pat. application Nos. 295,463 and 67.11574 laid open for public inspection. In this switchgear the transverse partition walls are provided in compartments used for isolator-switches and each partition wall consists of two coaxial discs adapted to be moved in their planes together and axially in respect of each other and to be forced, in their closed position, as a valve against a seat formed on the envelope. Such a composite transverse partition wall can not be easily made resistant to pressure, so that at the occurrence of a considerable increase of pressure or an explosion in one of the parts of the isolatorswitch compartment the risk is great, that the relative disc is forced from its seat, the driving mechanism of the discs is wrenched out of position and leakage occurs.

The invention has for its object to provide a transverse partition wall for such switchgear which has a simpler construction, resists explosions better and gives a better seal when the pressure in the parts of the compartment separated by the partition wall increases. This is achieved in that the partition wall consists of one single plate-shaped slide valve kept in its path by guides and adapted to be positioned into two end positions and said slide valve has an uninterrupted portion which separates, in one end position of the slide valve, the parts of said compartment from one another and a portion with a hole which interconnects, in the other end position of the slide valve, the parts of said compartment, whereas on each one of the two sides of the slide valve an axially movable sealing ring supported by the envelope of the compartment is provided, said ring being forced, at least in the closed condition of the slide valve, against said valve by springs and forming on its outer circumference with said envelope as well as on its end surface facing the slide valve with said valve gas-tight seals. In contrast with the known discs this valve is held against axial movement by its guides. The sealing rings can not be lifted from the valve at an increase of pressure, so that also at the event of an explosion a reliable seal is ensured. Moreover, if at least between the end face of each sealing ring facing the slide valve and the slide valve, when it is in its closed end position, a packing ring is provided, of which the inner diameter is smaller than the outer diameter of the relative sealing ring said ring will be pressed against the valve with increasing force, when the pressure in the part of the compartment closed by the valve and said ring increases, so that the seal adapts itself to the prevailing pressure difference and is thus maintained.

In order to facilitate the movement of the valve a construction is recommended, in which each sealing ring is provided with rollers mounted for rotation about axes which are parallel to the plane of the slide valve and are directed transversely to the direction of movement thereof, said rollers rolling during the movement of the slide valve on the surface of the slide valve which faces the relative sealing ring and holding said ring free from the slide valve, and the slide valve, is provided with recesses in the surface facing said sealing ring, said rollers engaging, at least in the closed end position of the slide valve, said recesses, in such a manner, that said ring is forced against the slide valve by its springs. In order to prevent that during the movement of the slide valve the rollers of the sealing ring enter recesses of the valve which are not intended for them, it is advantageous to place the rollers of each sealing ring in such a manner that each one of them follows, during the movement of the slide valve, an individual path on the slide valve which is free from the recesses of said valve intended for the other rollers.

It appears from the Dutch Pat. application No. 67.11574 laid open to public inspection that in each compartment adapted to be divided by a transverse partition wall and containing a switch, of which the fixed contact is found on one side and the axially movable switching rod cooperating with said fixed contact is found, when it is in its switched-off position, on the other side of said partition wall, said switching rod extending through a bushing insulator which is mounted between said compartment and an adjacent compartment separated therefrom and, when it is in its switched-off position, extending partly in one partly in the other compartment, means may be provided which establish in the switched-off position of said switching rod a connection between the two compartments. In said known switchgear said means consist of a connecting conduit or passage comprising a valve controlled by the movable transverse partition wall. However, as the transverse partition wall can only be positioned in its closed position, when the switch is switched-off, said connection between the two compartments can be obtained in a simpler and less vulnerable way, when said switching rod is provided with a passage which interconnects the two compartments exclusively when said rod is in its switched-off position. In that case the switching rod operates at the same time as a valve for the purpose referred to.

The invention will be further elucidated with the aid of the drawing. In the drawing:

FIG. 1 is a diagrammatical view of a part of metal-clad switchgear according to the invention,

FIG. 2 is a longitudinal sectional view of a valve mechanism and accessories used in the switchgear shown in FIG. 1,

FIG. 3 is a cross-sectional view taken on line III-III in FIG. 1 and FIG. 4 is, on a smaller scale, a plan view of the valve body and a sealing ring of the valve mechanism shown in FIGS. 2 and 3 and seen in the plane IV-IV shown in FIG. 3.

In FIG. 1 the shown part of the switchgear consists of

compartments

2, 3, 4 separated from each other by

bushing insulators

5, 6 and surrounded by an envelope 1 which has to be connected with earth. The compartment 3 can be divided by a transverse partition wall 7 adapted to be moved in its plane into two

parts

30, 3b which are separated from one another in a gas-tight manner. These

parts

3a, 3b of the compartment 3 are interconnected by a chamber 8, in which the partition wall 7 is mounted for movement. The compartment 2 contains switches and accessories which are not further described. Accommodated in the compartment 3 is an isolator-switch, of which the fixed contact 9 is found in the part 3b below the partition wall 7 and the switched-off switching rod 10 is found in the part 3a above the partition wall 7. The compartment 4 contains a busbar 11 of a busbar-system.

It appears from FIGS. 2, 3 and 4 that the transverse partition wall 7 can be constructed as a single plate-shaped slide valve, of which one portion 7a is uninterrupted and an other portion 7b lying in the direction of movement next to said portion 7a has a hole 12. If the slide valve 7 is positioned with its uninterrupted portion 7a in the compartment 3 (FIG. 2) the

parts

3a and 3b of said compartment are separated from each other. If the slide valve 7 is positioned with its portion 7b provided with the hole 12 in said compartment the

parts

30 and 3b thereof are in open communication with one another and the isolator-

switch

9, 10 can be switched in and off.

The valve 7 is provided on its longitudinal sides with guiding ribs 13 which slidingly engage grooves 14 formed in strips 15 of a frame forming part of the envelope of the chamber 8. This frame may be directly attached to the base of the switchgear. The valve 7 is thus held against movement in a direction perpendicular to its plane.

Provided in the

annular portions

16a, 16b of the envelope 1 which surrounds the

parts

3a and 3b of the isolator-switch compartment 3 are coaxial, axially

movable sealing rings

17a, 17b which each

support pressure members

18a, 18b and are each forced against the valve 7 by springs 19a, 19b lying against said pressure members. Each one of the

sealing rings

17a, 17b is provided on its circumference with a

packing ring

20a, 20b which forms a gas-tight seal between the sealing ring and the

envelope portion

16a, 16b. In its uninterrupted portion 7a the slide valve is provided with a

packing ring

21a, 21b, against which the sealing

ring

17a, 17b is forced. The inner diameter of the

packing ring

21a, 21b is smaller than the outer diameter of the

sealing ring

17a, 17b, so that, when for instance a higher gas pressure prevails in the portion 3a of the isolator-switch compartment 3 than in the part 3b of said compartment and in the chamber 8, the sealing ring 70 is also forced against the slide valve 7 by the difference in gas pressure. That is why under all circumstances, consequently also at the event of an explosion, a reliable seal is ensured between the

parts

3a and 3b of the compartment 3, when the slide valve is closed.

In order to facilitate the sliding movement of the slide valve 7 each

sealing ring

17a, 17b is provided with

rollers

22a, 23a, 24a, 25a and 22b, 23b, 24b, 25b mounted for rotation about axes which are parallel to the plane of the slide valve and are directed transversely to the direction of movement thereof. If these rollers roll on the sides of the slide valve they keep the

sealing rings

17a and 17b lifted from the slide valve. However, the slide valve is locally provided in its portion 7a with

recesses

26a, 27a, 28a, 29a and 26b, 27b, 28b, 29b which are so arranged that, when the slide valve 7 is in its closed end position, the rollers 22-25 engage the recesses 26-29 and the

sealing rings

17a and 17b are forced against the sliding valve by their

springs

19a, 1%. It is observed, that in the illustrated embodiment such recesses are also present in the portion 7b of the slide valve, so that the

sealing rings

17a and 17b are also forced against the slide valve, when the latter is in its open position. However, this is not always necessary. Due thereto contaminating products produced by the switching operation can not enter the chamber 8 and the guides l3, 14 of the slide valve 7.

The rollers 22-25 are so positioned, that each one of them follows its own path on the valve 7. Owing thereto it is prevented that, during the movement of the slide valve, a roller enters a recess 26-29 of the slide valve which is not intended for said roller.

If the valve 7 is closed, it is possible that the volume of each

part

30, 3b of the isolator-switch compartment 3 becomes dangerously small, what may result in a too rapid increase of pressure in such a part at the occurrence of a short circuit to earth. That is why the part 3b of said compartment is permanently connected with the compartment 4 by means of openings 30 made in the insulator 6 (FIG. I), whereas provided in the switching rod is a passage 31 which forms, exclusively in the switched-off position of the switching rod [0, a connection between the part 3a of the compartment 3 and the compartment 2. The switching rod 10 thus operates also as a valve in a connecting conduit provided between the

compartments

2 and 3.

What we claim is:

1. Metal-clad switchgear for high voltage comprising a gasfilled metal envelope intended to be connected with earth, a

number of compartments formed in said envelope, a chamber interconnecting two parts of one of said compartments, a plate-shaped slide valve accommodated in said chamber and adapted to form therein a transverse partition wall, said slide valve being mounted for movement in its plane and adapted to separate said compartment parts from one another and from said chamber in a gas-tight manner, guides for holding said slide valve in its path, one portion of the slide valve being uninterrupted and separating the two parts of said compartment, when the slide valve is in its one end position, a hole formed in another portion of the slide valve and interconnecting the two parts of said compartment, when the slide valve is in its other end position, two sealing rings being axially movably supported by said envelope, each one of said sealing rings bein provided on an individual side of the slide valve, springs to orce said sealing rings towards said slide valve, and

gas-tight seals being formed, at least when the slide valve is in its closed end position, both between the outer circumferences of said sealing rings and the envelope and between the one end faces of said sealing rings and said slide valve.

2. Metal-clad switchgear as claimed in claim 1, comprising in addition packing rings which are confined, when the slide valve is in its closed end position, between the one end faces of the sealing rings and the slide valve, the inner diameter of said packing rings being smaller than the outer diameter of said sealing rings.

3. Metal-clad switchgear as claimed in claim 1, comprising in addition sets of rollers mounted for rotation on the sealing rings about axes which are parallel to the plane of the slide valve and directed transversely to the direction of movement thereof, said rollers rolling during movement of the slide valve on the surfaces thereof and holding said sealing rings free from the slide valve, and recesses formed in the surfaces of the slide valve, each roller engaging, at least when the slide valve is in its closed end position, such a recess so as to allow the sealing rings to be forced against the slide valve by their springs.

4. Metal-clad switchgear as claimed in claim 3, in which the rollers of each sealing ring are so arranged as to follow, during the movement of the slide valve, their own paths on said valve, the path of each roller being free from the recesses formed in the slide valve and cooperating with the other rollers.

5. Metal-clad switchgear as claimed in claim 1, comprising in addition a fixed contact, an axially movable switching rod cooperating therewith, said fixed contact and said switching rod constituting together a switch, said switch being accommodated in the compartment provided with the slide valve, said fixed contact being arranged in the part of said compartment on one side and said switching rod being situated, when it is in its switched-off position, partly in the part of said compartment on the other side of the chamber containing the slide valve, a second compartment adjacent to said first mentioned compartment, a bushing insulator provided in the wall between the two compartments, said switching rod extending through said bushing insulator and being found, when it is in its switched-off position, in both compartments and a passage formed in said switching rod, said passage interconnecting said two compartments only when the switching rod is in its switched-off position.

8 i t t 1

Claims

1. Metal-clad switchgear for high voltage comprising a gasfilled metal envelope intended to be connected with earth, a number of compartments formed in said envelope, a chamber interconnecting two parts of one of said compartments, a plateshaped slide valve accommodated in said chamber and adapted to form therein a transverse partition wall, said slide valve being mounted for movement in its plane and adapted to separate said compartment parts from one another and from said chamber in a gas-tight manner, guides for holding said slide valve in its path, one portion of the slide valve being uninterrupted and separating the two parts of said compartment, when the slide valve is in its one end position, a hole formed in another portion of the slide valve and interconnecting the two parts of said compartment, when the slide valve is in its other end position, two sealing rings being axially movably supported by said envelope, each one of said sealing rings being provided on an individual side of the slide valve, springs to force said sealing rings towards said slide valve, and gas-tight seals being formed, at least when the slide valve is in its closed end position, both between the outer circumferences of said sealing rings and the envelope and between the one end faces of said sealing rings and said slide valve.