Gas exhaustion arrangement for high-current circuit breaker - uses expansion chamber in form of convergent duct with circulation blocks to exhaust arc gases to atmosphere

摘要

The gases generated during operation of electric circuit breakers are released from the arcing chamber into an expansion chamber coupled to the arcing chamber. A decompression chamber in the form of ducts (31,32) is formed in a volume above the arcing chamber. Holes (19,20) are provided in the wall separating the arcing chamber from the expansion chambers to allow passage of the gas. The expansion chambers are shaped to form a stepwise convergent duct, leading the arc produced gases to atmosphere. To reduce circulation of gases, in the expansion chamber a narrow neck may be incorporated in the outlet path, or alternatively a restriction such as a chicane, grille, perforated sheet or parallel bars may be placed near the gas outlet (35).