Blast-nozzle arrangement on a gas-blast circuit breaker

摘要

A nozzle body (24) has an inlet (23) which converges in the flow direction and is connected to a pressure space (17) which can be pressurized during a switching-off stroke. Connected to the inlet (23) is a very narrow point (26) from which a blast space (27) originates, which diverges like a diffuser. Passages (29) originate from the nozzle space in the region of the very narrow point (26), which passages (29) are intended to relieve the load of pressure surges on the nozzle body (24), which pressure surges occur in the region of the very narrow point (26) as a result of the switching arc which is ignited during a switching-off stroke. In order not only to keep the heated, highly pressurised gas which escapes through the passages (29) away from the space surrounding the nozzle body (24) but also to utilize the kinetic energy of the gas flow in the passages (29) for supporting the gas flow in the nozzle space of the nozzle body (24), the passages (29) open into the blast space (27) downstream of the very narrow point (26). <IMAGE>