Patent ID: 7402771

Claim:
A circuit breaker which has in an enclosure filled with an insulating gas at least one interrupting chamber extending along a longitudinal axis comprising: an arcing volume; and at least two associated arcing contacts, the arcing volume being actively connected to at least one exhaust having an exhaust volume which is constructed for cooling hot gases generated during breaking operations and is connected to a volume of the interrupting chamber, wherein in the area of the exhaust at least one forcibly created recirculation area is provided which increases the flow resistance of the hot gases, wherein the hot gases flow from the arcing volume into an intermediate volume, following the intermediate volume, a flow tube constructed in the manner of a laval nozzle and having a nozzle constriction leads into the exhaust volume which is connected to the interrupting chamber volume, in the intermediate volume, at least one baffle plate protruding into the flow of the hot gases is provided, downstream of which a first recirculation area forms, between the entry for the hot gases into the intermediate volume and the baffle plate, a distance L 1 is provided, between the baffle plate and the nozzle constriction, a distance L 2 is provided, and that between the nozzle constriction and an exit edge of the flow tube, a distance L 3 is provided.