Electric arc-blast nozzle and a circuit breaker including such a nozzle

Patent metadata

Field	Value
Publication number	US-10692673-B2
Application number	US-201716312622-A
Country	US
Kind code	B2
Filing date	Jun 21, 2017
Priority date	Jun 29, 2016
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

A nozzle with an electric arc-blast having a median part of a first dielectric material and two end parts. The nozzle includes an insert of a second dielectric material, chosen from among:
a composite material including a fluorocarbon polymer matrix and inorganic filler A chosen from among a sulfur, a ceramic and an oxide (SiO2, TiO2, Al2CoO4, ZnO, BaTiO3 and P2O5), in a percentage weight ranging between 0.1% and 10%, and/or at least one inorganic filler B (a graphite, a mica, a glass and a fluoride), in a percentage weight ranging between 5% and 50%, and a ceramic material including compound(s) (a carbide, a boride and an oxide).

First claim

We claim:

1. An electric arc-blast nozzle for a circuit breaker comprising:
a neck-forming median part internally defining an axial passage for cutting an electric arc and formed with a first dielectric material obtained from a first composition comprising a fluorocarbon polymer matrix,
two end parts extending on either side of the median part which are respectively intended to receive arc contacts that can be axially moved in relation to each other, between a circuit breaker opening position in which the arc contacts are separated from each other and a circuit breaker closing position in which the arc contacts are in contact with each other and in which one of the arc contacts partially closes the axial passage of the median part, an electric arc cut-off gas circulating in the axial passage of the median part to cut the electric arc that is likely to be formed during movement of the arc contacts from the closing position to the opening position of the circuit breaker, and
an insert, that defines a downstream area of the axial passage of the median part considering a direction of a flow of the electric arc cut-off gas and is, also, formed with a second dielectric material, different from the first dielectric material and from among:
a composite material obtained from a second composition comprising a fluorocarbon polymer matrix and:
at least one inorganic filler A comprising at least one of MoS2, Sb2Ss or Sb2S3, a ceramic, BN, and an oxide comprising at least one of Si02, Ti02, AhCoQ4, ZnO, BaTiQ3 and P205, in a percentage weight ranging between 0.1% and 10%, with respect to a total weight of the second composition, and/or
at least one inorganic filler B comprising at least one of a graphite, a mica, a glass and a fluoride, in a percentage weight ranging between 5% and 50%, with respect to the total weight of the second composition, and
a ceramic material obtained from a third composition comprising at least one compound comprising at least one of a carbide, a boride and an oxide.

2. The nozzle according to claim 1 , wherein the inorganic filler A is chosen from BN and Si02.

3. The nozzle according to claim 1 , wherein the percentage weight of the inorganic filler(s) A ranges between 0.2% and 5%, with respect to the total weight of the second composition.

4. The nozzle according to claim 1 , wherein the percentage weight of the inorganic filler(s) B ranges between 10% and 30%, with respect to the total weight of the second composition.

5. The nozzle according to claim 1 , wherein the composite material has a gradient of percentage weights of inorganic filler(s) A and/or B in the fluorocarbon polymer matrix which increases in the direction of the flow of the electric arc cut-off gas.

6. The nozzle according to claim 1 , wherein the second composition comprises only one inorganic filler A.

7. The nozzle according to claim 1 , wherein the compound of the third composition comprising at least one of SiC, ZrC, HfC, ZrB2, HfB2, SiO2, and ZrO2.

8. The nozzle according to claim 1 , wherein the third composition also comprises at least one inorganic filler.

9. The nozzle according to claim 1 , wherein the first composition further comprises at least one inorganic filler C in percentage weight, with respect to the total weight of the first composition, of less than or equal to 10%, except where the inorganic filler C comprising inorganic fillers A and/or B, in which case the percentage weight of the inorganic fillers C is less than the percentage weight of the inorganic filler(s) A and/or B of the second composition.

10. The nozzle according to claim 9 , wherein the inorganic filler C comprising at least one of MoS2 and AhCo04.

11. The nozzle according to claim 1 , wherein the first composition does not comprise the inorganic filler.

12. The nozzle according to claim 1 , wherein the fluorocarbon polymer of the first and second compositions is chosen from polytetrafluoroethylene, a copolymer of ethylene and tetrafluoroethylene and, a polyfluoride of vinylidene.

13. The nozzle according to claim 1 , wherein a length of the insert present in the median part represents no more than 30%.

14. The nozzle according to claim 1 , wherein the insert forms a section of the median part.

15. The nozzle according to claim 1 , wherein the insert extends up to a downstream end of the median part.

16. The nozzle according to claim 15 , wherein the insert extends beyond the downstream end of the median part in at least one area of an internal peripheral surface of the end part disposed downstream considering the direction of the flow of the electric arc cut-off gas, the internal peripheral surface being in a shape of a truncated cone.

17. The nozzle according to claim 1 , wherein the end part disposed upstream and, where required, at least a portion of the end part disposed downstream are formed with the first dielectric material, the upstream and downstream disposition of the end parts considering the direction of the flow of the electric arc cut-off gas.

18. The nozzle according to claim 1 , further comprising a sheath disposed on an external surface of each of the two end parts and the neck-forming median part.

19. A high voltage circuit breaker comprising:
at least two arc contacts and that can be axially moved in relation to each other, between the circuit breaker opening position in which the arc contacts are separated from each other and the circuit breaker closing position in which the arc contacts are in contact with each other,
the electric arc-blast nozzle defined according to claim 1 , and
the electric arc to cut-off gas circulating in the axial passage of the median part of the nozzle to cut the electric arc that is likely to be formed during the movement of the arc contacts from the circuit breaker closing position to the circuit breaker closing position.

20. A circuit breaker according to claim 19 , wherein the electric arc cut-off gas comprising of at least one of carbon dioxide CO2, sulfur hexafluoride SF6 and is a gaseous mix comprising CO2.

Assignees

• General Electric Technology Gmbh

Inventors

• Ledru Roger
• Vigouroux Daniel

Classifications

• H01H33/7023 Primary

  characterised by an insulating tubular gas flow enhancing nozzle (H01H33/7038 takes precedence) · CPC title

• H01H33/91

  the arc-extinguishing fluid being air or gas · CPC title

• H01H33/7069

  characterised by special dielectric or insulating properties or by special electric or magnetic field control properties (H01H33/7023 - H01H33/7061 take precedence) · CPC title

• H01H33/7076

  characterised by the use of special materials (H01H33/7023 - H01H33/7069 take precedence) · CPC title

• H01H33/703 Primary

  having special gas flow directing elements, e.g. grooves, extensions · CPC title