Nozzle in gas blast circuit breaker - has neck with alternating fluoro:polymer and boron nitride-filled fluoro:polymer layers in outer sleeve and at right angles to breaker axis

摘要

An electrically insulating nozzle made of fluoro-polymer and boron nitride is symmetrical axially and has a point of construction where it is exposed temporarily to an arc. At least around the construction the nozzle is made of a composite material consisting of alternate layers at right angles to the longitudinal axis, these layers are made of virtually "dope"-free fluoro-polymer heavily filled with boron nitride. Pref. polymers contain PTFE, polyvinylidene-fluoride, polyvinylfluoride and/or ethylene-tetrafluoroethylene. ADVANTAGE - The nozzle suffers little loss even when exposed to an intense arc and it still retains high mechanical strength. It is suitable for compressed gas blast circuit breakers which retain their function even after numerous operations with high currents and which continue to have good insulation.