A movable main contact; a movable arc contact; a puffer cylinder including the movable main contact; a hollow rod that is arranged inside the puffer cylinder, includes the movable arc contact, and has an inner space through which an insulating gas flows; a thermal puffer chamber surrounded by the puffer cylinder and the hollow rod; an insulating cover that is provided to the hollow rod, and covers the movable arc contact; an insulating nozzle provided to the puffer cylinder; and a cylindrical flow guide extending in the axial direction are included. The flow guide is installed in the thermal puffer chamber, positioned on the outer circumference side of the hollow rod, and connected to the insulating nozzle. The space between the flow guide and the hollow rod is connected to the space between the insulating nozzle and the insulating cover, and serves as a flow path of the insulating gas.

To provide a gas circuit breaker designed to achieve further improvement in interruption performance for a small to medium current. The gas circuit breaker according to the present invention includes: an operation mechanism 1; a heat puffer chamber 19; a machine puffer chamber 32; a release valve 34; a movable main contact 5 and movable arc contact 11; a stationary main contact 6 and stationary arc contact 12; a movable-side leading conductor 14; and a stationary-side leading conductor 15, and features: a separation cylinder 21 for radially partitioning the heat puffer chamber 19; an inner circumferential flow path 24 formed on an inner circumferential side of the separation cylinder 21; and a check valve 22 for opening or closing a communication hole 23.

To improve cooling performances of quenching gas in a gas blast switch comprising a gas channel connecting an arcing region to a gas storage chamber delimited by radially opposite inner and outer walls and axially opposite first and second end walls, a flow guiding radial wall extends in the gas storage chamber spaced from each wall delimiting the chamber, an opening of the gas channel into the gas storage chamber through the first end wall faces a space between the flow guiding radial wall and the inner wall, the outer wall includes a deflecting portion protruding in the gas storage chamber and facing the second end wall, and at least part of the deflecting portion is offset from the flow guiding radial wall in an axial direction oriented from the gas channel towards the gas storage chamber.

To improve cooling performances of quenching gas in a gas blast switch comprising a gas channel connecting an arcing region to a gas storage chamber delimited by radially opposite inner and outer walls and axially opposite first and second end walls, a flow guiding radial wall extends in the gas storage chamber spaced from each wall delimiting the chamber, an opening of the gas channel into the gas storage chamber through the first end wall faces a space between the flow guiding radial wall and the inner wall, the outer wall includes a deflecting portion protruding in the gas storage chamber and facing the second end wall, and at least part of the deflecting portion is offset from the flow guiding radial wall in an axial direction oriented from the gas channel towards the gas storage chamber.

To provide a gas circuit breaker designed to achieve further improvement in interruption performance for a small to medium current. The gas circuit breaker according to the present invention includes: an operation mechanism 1; a heat puffer chamber 19; a machine puffer chamber 32; a release valve 34; a movable main contact 5 and movable arc contact 11; a stationary main contact 6 and stationary arc contact 12; a movable-side leading conductor 14; and a stationary-side leading conductor 15, and features: a separation cylinder 21 for radially partitioning the heat puffer chamber 19; an inner circumferential flow path 24 formed on an inner circumferential side of the separation cylinder 21; and a check valve 22 for opening or closing a communication hole 23.