Self-blast circuit breaker using the two-phase state of a gas to improve the cut-off properties

A breaking chamber for a medium- or high-voltage circuit breaker extending along a longitudinal axis (XX′) and comprising:

• a pair of arcing contacts, at least one of which is movable along the longitudinal axis (XX′) under the action of a drive member, the contacts separating when current is interrupted;
• an arc-blast nozzle that is secured to the stationary arcing contact;
• a first chamber, referred to as a “blast” chamber, having a volume (V2) that is constant and that opens out inside the blast nozzle;
• a second chamber, referred to as a “compression” chamber, arranged substantially behind the blast chamber, parallel to the longitudinal axis (XX′), and means for putting the internal volume of said compression chamber into communication with the blast chamber;
• and
• means, disposed substantially behind the compression chamber, parallel to the longitudinal axis (XX′), in order to deliver liquid, either to the compression chamber, or directly to the blast chamber.

A breaking chamber for a medium- or high-voltage circuit breaker extending along a longitudinal axis (XX′) and comprising:

• a pair of arcing contacts, at least one (5) of which is movable along the longitudinal axis (XX′) under the action of a drive member, the contacts separating when current is interrupted;
• an arc-blast nozzle that is secured to the stationary arcing contact;
• a first chamber, referred to as a “blast” chamber, having a volume V2 that is constant and that opens out inside the blast nozzle;
• a second chamber, referred to as a “compression” chamber, arranged substantially behind the blast chamber, parallel to the longitudinal axis (XX′), and means for putting the internal volume of said compression chamber into communication with the blast chamber;
• and
• a liquid injector, or a third chamber and a piston that is able to move inside said third chamber under the action of a backwards movement of the movable equipment of said chamber, said liquid injector or said third chamber being disposed substantially behind the compression chamber, parallel to the longitudinal axis (XX′), in order to deliver liquid, either to the compression chamber, or directly to the blast chamber.