Gas circuit breaker

A gas circuit breaker comprising:

• a cylindrical movable-side main conductor supportively fixed by an insulation cylinder disposed in a gas-filled envelope containing an insulation gas having an arc-extinguishing property, connected to a movable-side leading conductor connected to an electric power system, and including an exhaust hole for exhausting a high temperature and pressure gas as the insulation gas raised in temperature and pressure by a generated arc;
• a hollow exhaust shaft disposed in the movable-side main conductor and movable in an axial direction of the movable-side main conductor;
• an operation mechanism coupled to the exhaust shaft and outputting a force operating in an axial direction of the exhaust shaft;
• a cylinder coaxially coupled to the exhaust shaft and axially slidable on an inside surface of the movable-side main conductor, a piston coupled to the cylinder, an insulation nozzle coupled to the piston, and a heat puffer chamber enclosed by the cylinder;
• a blast-gas flow path communicating the heat puffer chamber and an arc space, and defined by a gap between the insulation nozzle and a movable element cover;
• a puffer piston fixed to the inside of the movable-side main conductor, and including an opening which is opened in the axial direction of the movable-side main conductor and whose inside surface allows the exhaust shaft to slide thereon;
• a hole communicating a movable-side conductor inner circumferential space defined on the operation mechanism side as seen from the puffer piston and a machine puffer chamber formed on the opposite side from the operation mechanism;
• a release valve for releasing the insulation gas from the machine puffer chamber into the movable-side conductor inner circumferential space when the machine puffer chamber is compressed by the exhaust shaft and the cylinder axially moved by the operation mechanism;
• a movable contact electrically connected to the movable-side leading conductor;
• and
• a contact which is electrically connected to a stationary-side leading conductor connected to the electric power system and is in contactable/separable relation with the movable contact,
• the gas circuit breaker featuring:
• a separation cylinder disposed in a manner to radially partition the heat puffer chamber;
• an inner circumferential flow path defined by the separation cylinder on an inner circumferential side of the heat puffer chamber;
• and a straightening mechanism for opening or closing a communication hole communicating the inner circumferential flow path and the machine puffer chamber,
• wherein a distal end of the separation cylinder is located in a blast-gas flow path, and
• wherein the distal end of the separation cylinder is connected to the movable element cover, and the movable element cover includes a movable element cover communication hole for communicating the inner circumferential flow path and the blast-gas flow path.