首页>
外国专利>
Arc quenching chamber for high capacity circuit breaker - has contact surfaces forming Coanda nozzle for control of high velocity quenching stream along sharp bends(RU 12.12.77)
Arc quenching chamber for high capacity circuit breaker - has contact surfaces forming Coanda nozzle for control of high velocity quenching stream along sharp bends(RU 12.12.77)
The Coanda type nozzle for an arc quenching stream can be a separate piece made of an inexpensive material, e.g. copper, attacheable to the mobile contact by a contact surface, the entire assembly being pressed by a spiral spring into the contact position. Beginning from the moment of the main breakers separation, the thin ionised stream is blown through the nozzle channel, the arc quenching stream being accelerated and deviated close to the contoured nozzle wall with an increase of the electric arc zone deionisation effect achieved as well as a better flushing of its roots. A bending of the stream at the mouth of the nozzle is caused by a small step at the very lip of the mouth which facilitates the Coanda-effect of the internal type. Hollow arc quenching chambers can additionally achieve the external Coanda type effect, here the high pressure being located at first in their interior and from the moment the breakers are opened, the curving of the arc quenching stream to the contact's exterior is achieved, the deionisation being easier in an external Coanda-nozzle. The cross-blast type of quenching chamber can have a fixed contact juxtaposed with high pressure cylinder slots having the shape of Coanda-nozzles, thus increasing the electric arc deionisation effect.
展开▼
