Automatic sprinkler spray head with pyrotechnic release - uses electrically ignited pyrotechnic device to boil liq. so spray head can be opened under vapour pressure

摘要

The automatic sprinkler (1) for fire protection in buildings uses destruction of the support (3) holding the sprinkler in the closed position to permit ejection of the closure assembly (3,5,6) and thus permit water flow. A pyrotechnic actuator (15) is coupled (18,19) to the closure assembly support (3). A bifilar electric conductor (22) is used to ignite the pyrotechnic actuator (21), and the heat generated is used to heat a low boiling point liq. in the closure assembly support (3). The vapour pressure generated is sufficient to displace the support, allowing the closure valve to move clear of its seat, releasing water onto the spray head.