JPH0664976B2 - Pressure gas switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to two cylindrical contact members (2, 3) which are movable relative to each other along a cylinder axis, and which surrounds the contact members (2, 3) coaxially. And a heat chamber (5) for receiving arc-extinguishing gas, the heat chamber (5) extending axially longer than radial direction,
The arc-extinguishing gas is heated by the switching arc (11) which burns between both contact members (2, 3) during the switching process, resulting in an annular gap (6).
Starting from a pressure gas switch which is led to the heat chamber (5) and is mixed there with cold arc-quenching gas.

In this superordinate concept, the invention relates to a state-of-the-art pressure gas switch as described in EP-AI0067460.
In the well-known switch, the extinguishing gas heated by the switching arc is stored in a torus-shaped heat chamber that coaxially surrounds the contact member, and when the heating effect of the arc diminishes when approaching zero current, it becomes an annular chamber. Flowing. In this annular chamber, the extinguishing gas is mixed with fresh extinguishing gas from the piston-cylinder-compressor, so that the mixed gas has a lower temperature than the heated extinguishing gas. The arc-quenching gas, which has been mixed to a relatively low temperature, is subsequently guided to the contacts and breaking distances present between both contact elements, where the arc-quenching gas effectively blows out the switching arc. However, such a switch is relatively expensive and additionally requires additional drive energy to drive the compression device.

The invention is characterized in that the arc-quenching gas used for the dielectric restabilization of contacts and breaking distances saves compression equipment and heats up at the end of high currents, as characterized in the claims. It solves the problem of attempting a pressure gas switch of the type mentioned at the outset, which can be treated freely at the gas temperature which is predominantly present below the temperature of the arc-quenching gas.

This problem is combined with the features of the superordinate idea to claim 1
It is solved by the characteristic part of. The pressure gas switch according to the invention almost optimally mixes the heated arc-extinguishing gas with the cold arc-extinguishing gas stored in the heat chamber before the switching process, so that a zero-current after-contact and a breaking distance of the dielectric arc. It is outstanding because it can freely treat arc-quenching gas that has been sufficiently cooled for effective re-stabilization. At the same time, predominantly axially widened heat chambers can be used, which are advantageous for cost considerations and constructional reasons.

Further advantageous developments of the invention are indicated in the embodiments section.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings.

Here, one drawing shows a plan view of a pressure gas switch formed according to the present invention, taken along its contact member axis.

In the figure, a pressure gas switch formed in accordance with the present invention is shown in the on position in the left part, whereas in the right part it is shown broken. Shown here is a housing filled with an arc-quenching gas such as sulfur hexafluoride, perhaps at a pressure of a few bar. In this housing 1 there is a contact member 2 formed as a fixed nozzle tube into which a movable solid cylindrical contact member 3 is inserted in the on position. When the contact member 3 is in the on position, it penetrates through an opening (not shown) of the insulating substance body 4 formed as a nozzle, which is attached to the contact member 2. The insulating material body 4 is provided with a heat chamber 5 that surrounds the contact members 2 and 3 in a toroidal shape.
And an annular gap 6 is provided between the insulating substance body 4 and the upper end of the contact member 2, and the annular gap is separated from the inside of the contact member 2 by the contact member 3 at the ON position. The heat chamber has an axial extension L which is several times larger than its radial depth D.

Inside the heat chamber 5 there is mounted a cylindrical mantle-shaped separating wall 7, which is probably made of an insulating material such as polytetrafluoroethylene and which surrounds the contact members 2, 3 coaxially. The chamber 5 is subdivided into two chambers 8 and 9. Both chambers are annular in cross section. The chamber 8 is surrounded by the chamber 9 and is connected to this via an opening 10 in the inner wall 8. The chamber 8 has a relatively slight depth in the radial direction with respect to the chamber 9 and opens into the annular gap 6. Opening 10
The contact members are arranged with an azimuth angle on a circle drawn as the center of the axis of the contact member, and the distance between the center points in the axial direction of the contact members corresponds to the depth d of the outer chamber 9 extending substantially in the radial direction.

The operation of this switch is as follows.

The contact member 3 is moved upward when breaking (right side in the figure). As soon as the contact members 2 and 3 are separated, a switching arc 11 is formed between them. In the high-current phase, the switching arc violently heats the arc-extinguishing gas present at the contact point or the break distance between the contact members 2 and 3, thereby increasing its pressure. The high-pressure heated arc-quenching gas flows into the heat chamber 6 through the annular gap 6 which is relatively large with respect to the opening of the contact member 2 and there in the chamber 8 along the separating wall 7,
It is guided to the upper and lower ends of the chamber 8 defined by the insulating substance body 4.

The flow cross section of the chamber 8 formed as an annular channel need not be larger than the flow cross section of the annular gap 6.
This is because it is then ensured that the flow of the heated arc-quenching gas indicated by the arrow takes place virtually without resistance in the entire transport. A particularly advantageous flow process is achieved when the radial depth of the first chamber 8 decreases axially at least partially from the junction of the annular gap 6.
The annular gap 6 acting as an inlet opening of the heat chamber 5 is
Alternatively, the flow cross-section of the chamber 8 can be kept significantly smaller than the flow cross-section of the annular gap 6 if they are approximately the same distance from the upper and lower ends of the chamber 8. This is because in this case the extinguishing gas stream is distributed into two approximately equal-sized partial streams moving along the separating wall 7 to the upper and lower ends of the chamber 8.

The heated arc-extinguishing gas guided along the separating wall 7
Only non-essentially mixes with the cold arc-quenching gas present in
And it is forced under increased pressure essentially through the opening 10 into the outer chamber 9. In this case, the opening 18 is dimensioned such that the pressure equilibrium between the chambers 8 and 9 occurs very quickly, even in the case of intense heating of the arc-extinguishing gas, owing to the high current to be interrupted. According to it, there are many separation walls 7 in the whole transport,
A thickness of 3 millimeters is sufficient. Aperture arranged in azimuth in a circle drawn around the cylinder axis
If the flow cross section of 10 is approximately the same as the flow cross section of the chamber 8 in the axial position of the chamber 8 attached to this circle, a favorable distribution of the incoming heated arc-quenching gas is achieved.

When the pressure is further increased by arc heating, the heated arc-quenching gas flows into the chamber 9 through the opening 10, where it mixes with the arc-quenching gas present there before pressure equilibration. In this case, the mixing limits 12, 13 and 14 between the arc-quenching gas mixed with the cold arc-quenching gas diffuse into the chamber 9 from the opening 10. By appropriately distributing the openings 10 in the inner wall 7, in the heat chamber 5 having a slight radial depth D but a relatively large axial extent L, the mixing range is almost entirely the chamber 9 when pressure balanced. It is possible to cover the volume.

Here, as a result of the mixing experiment, a depth-length-ratio D / L of about 0.1
In the heat chamber 5 having a space, the arc-extinguishing gas heated during the switching process is the cold arc-extinguishing gas present in the heat chamber 5 when the distance between the adjacent openings 10 corresponds approximately to the depth d of the chamber 9. It turned out to be almost completely mixed with. This allows
Mixing almost doubled for heat chambers with comparable dimensions D and L. For a heat chamber with a D / L ratio of 0.5,
With a correspondingly spaced arrangement of the openings 10, the mixing is still considerably improved for correspondingly dimensioned heat chambers.
Apertures having azimuth angles in a circle drawn around the cylinder axis can be evenly spaced from each other, but can also be formed as gaps extending azimuth about the cylinder axis. The separating wall 10 can then be fixed to the wall of the insulating body 4 which partitions the heat chamber 5 outwards, by means of a web which extends radially outwards.

After the high-current phase, the extinguished gas mixed and cooled in the chamber 9 flows through the opening 10 through the chamber 9 and the annular channel 6 which are formed into an annular channel and returns to the contact point or the disconnection distance, and Turn off arc 11. In this case, the nature of the arc-quenching gas acting on the contacts and the breaking distance is such that when exiting the opening 10 there is an additional intimate mixing with the unmixed, existing hot chamber-gas. It is further improved by being carried out.

[Brief description of drawings]

The drawing is a plan view of a pressure gas switch formed in accordance with the present invention, taken along the contact member axis. 1 ... Housing, 2, 3 ... Contact member 4 ... Insulating material main body, 5 ... Heat chamber 6 ... Annular gap, 7 ... Separation chamber 8 ... First chamber, 9 ... Second chamber 10 ... … Aperture, 11 …… Switching arc 12,13,14 …… Mixing limit, D …… Radial depth L …… Axial length extension d …… Radial depth

Claims (10)

[Claims] 1. Two cylindrical contact members (2,3) movable relative to each other along a cylinder axis, and a coaxially surrounding these contact members (2,3), and a radial axis. A switching arc (11) having a heat chamber (5) for receiving the extinguishing gas, which extends further in the direction, and the extinguishing gas burns between both contact members (2, 3) during the switching process. Is heated by and guided to the heat chamber (5) through the annular gap (6),
Then, in the pressure gas switch, which is adapted to be mixed with the cold arc-extinguishing gas, the heat chamber (5) is cross-sectioned by the separating wall (7) arranged coaxially with the contact members (2, 3). Is subdivided into two chambers (8, 9) formed in an annular shape, of which the first chamber (8) of both chambers (8, 9) is connected to the annular gap (6) and both chambers (8 , 9) is connected to the first chamber (8) through the opening (10) of the separation wall (7). 2. The first chamber (8) is formed as an axially extending annular channel with a slight radial depth compared to the second chamber (9). Pressure gas switch described in. 3. A pressure gas switch according to claim 2, wherein the annular gap (6) opens into the annular channel at substantially the same distance from both ends of the annular channel. 4. The pressure gas switch according to claim 2, wherein the annular gap (6) opens into the annular channel at one end of the annular channel. 5. Pressure gas according to claim 2, characterized in that the radial depth of the first chamber (8) decreases at least partly in the axial direction from the junction of the annular gap (6). switch. 6. A method according to claim 1, characterized in that the distance between adjacent openings (10) corresponds to at most twice the depth of the radially extending second chamber (9). The pressure gas switch according to any one of the above. 7. An opening (10) is arranged with an azimuth angle in a circle drawn around a cylinder axis, and the centers of the circles are spaced apart from each other by the depth (d) of the second chamber (9) extending in the radial direction. Pressure gas switch according to claim 6, corresponding to at most twice. 8. A pressure gas switch according to claim 7, wherein the opening (10) is formed as a gap extending azimuthally about the cylinder axis. 9. An annular channel (chamber) in which the flow cross section of all the openings (10) arranged azimuthally in a circle drawn around the cylinder axis is at the axial position of the annular channel corresponding to this circle. 8. A pressure gas switch according to claim 7 or 8 which is substantially the same as the flow cross section of 8). 10. The axial spacing of the openings (10) substantially corresponds to the radially extending depth (d) of the second chamber (9),
The pressure gas switch according to any one of claims 6 to 9.