SU922900A1 - Heavy-current liquid-metal switch - Google Patents

Description

The invention relates to the technique of switching high-current electric circuits of direct current, namely to switching equipment with liquid metal.

Known switching apparatus, in which switching is performed by moving a liquid metal due to hydrostatic pressure between the electrodes, made in the form of coaxial cylinders, separated by an insulating partition [1].

The disadvantage of this switch is a small resource of work, since the insulating surfaces are covered with a film of liquid metal, due to which the insulation resistance between the electrodes is reduced.

The closest to the technical essence of the present invention is a liquid metal switch containing an annular insulating chamber, two electrodes, one of which is made annular, ending with an arc-resistant nozzle installed coaxially with an annular insulating chamber and forms with H and her annular interelectrode and arcing channels, liquid me2

tall, piston with rod moving inside the annular electrode and magnetic blast [2].

5 However, the known switch is unreliable and has a small operating life due to the fact that after several commutation the insulating surfaces are covered with a liquid metal film, when large currents are disconnected, this film burns out, but burning products remain on the insulating surfaces, which reduces the insulation between the electrodes.

15 Purpose of the invention -. increase the reliability and durability of the switch.

This goal is achieved by

__ that the famous switch is supplied

spring-loaded gate of the interelectrode channel, and the piston rod is made with stops, between which the valve is freely fixed.

The drawing shows schematically a switch.

The switch consists of an insulating annular chamber 1, which is hermetically sealed by an electric holder 2 and an electrode 3, an annular elec-

922900

four

The electrode 4, which has an insulating arc-resistant nozzle 5 on its end facing the surface of the liquid metal. Its internal surface is insulated by the sleeve 6. The liquid metal 7 is displaced by the insulating piston 8 and closes the electrodes 3 and 4. The upper part of the interelectrode channel is blocked by a gate 9, which is turned on the position of the switch compresses the insulating elastic gaskets 10 th 11. The valve 9 is connected by a piston drive 8 with the help of holders 12 passing through the slots 13 of the electrode 4. From the splashing of insulating surfaces 7 by liquid metal The channel 14 through the slots 13 serves as a screen 14. The driving device of the insulating piston is not shown in the drawing. The switch is covered by the magnetic blast coils 15. The coils are shielded with a ferromagnetic casing 16. There are stops 18 on the piston rod 17, limiting the movement of the valve 9. A spring 19 serves to preload the valve 9.

The switch works as follows.

In the on position, the electrodes 3 and 4 with the liquid metal 7 form a closed circuit. The piston 8 is in its lowest position, the valve 9 is pressed against the gaskets 10 and 11 by the spring 19 and the stop of the rod 17 and protects the upper part of the insulating surface of the chamber 1 from wetting with liquid metal 7. When disconnected, the piston 8 rises up the rod 17 up, the magnetic blast 15 turns on, under the action of gravitational forces, the liquid metal 7 begins to move away from the channel between the housing 1 and the electrode 4, while the damper 9, preloaded by the spring 19, remains in the closed position. The shutdown arc that occurs in the insulation channel between the chamber 1 and the nozzle 5 , stretched around the circumference under the action of a magnetic blast, while cooled on insulating surfaces and extinguished.

The piston rod 17 of the piston 8 opens the valve 9 with the lower stop of the rod 17. · The insulating surface of the chamber 1, protected by the valve 9, remains clean of liquid metal. When the piston 8 is turned on, the rod 17 goes down, the valve 9, being freed from the stop 17 by the action of the spring 19, closes, after which the liquid metal 7 begins to fill the channel between the chamber 1 and the nozzle 5.

Thus, the flap represents the metallization of the insulating chamber, which leads to both increased reliability and durability.

Claims (1)

Claim High-current liquid metal switch containing an annular insulating chamber, two electrodes, one of which is made an annular, terminating arc-resistant nozzle mounted coaxially with an annular insulating chamber and forming with it annular inter-electrode and arcing channels, a liquid metal, a piston with a rod moving inside the annular electrode and magnetic blast coils, characterized in that, in order to improve reliability and durability, it is provided with a dummy *. the inter-electrode channel valve and the piston rod is made with stops, between which it is loosely fixed. indicated damper.