Puffer-type gas-blast circuit breaker

A puffer-type gas-blast circuit breaker comprising:

• a. a pair of electrodes, spaced apart during an interrupting operation, between which an arc is established,
• b. a dual-flow nozzle having a body primarily of electrical insulating material, a flow passage extending axially through said nozzle, through which said arc extends during an interrupting operation, said flow passage containing a throat of electrical insulating material and divergent sections at axially opposed sides of said throat,
• c. a plurality of injection passages extending generally radially of said nozzle in the region of said throat and intersecting said throat at the inner ends of said injection passages,
• d. a plurality of feed passages located within said nozzle body, communicating with said injection passages, and extending between said injection passages and one end of said nozzle,
• e. pump means located at said one end of said nozzle and operable during a circuit-breaker opening operation for injecting arc-extinguishing gas through said feed passages and said injection passages into said throat,
• f. and means for forcing the gas injected into said throat to flow within said flow passage axially of said arc in two streams directed in opposite directions from said throat toward said electrodes, said means comprising a plurality of exhaust ports at said one end of the nozzle extending transversely of said flow passage from said flow passage to the exterior of said nozzle in locations circumferentially spaced from said feed passages, the inner ends of said exhaust ports being disposed in a region surrounding one of said electrodes, one of said divergent sections defining a flow zone about the exterior of said one electrode leading to said exhaust ports.