US Patent 11635258 Exhaust hood overflow system

An overflow system for a doorway exhaust hood on a metal melt furnace having an eductor gas circulator. The system includes a manifold with an inlet near the hood's lower lip, and a conduit between the manifold and eductor. A blower draws gas into the manifold and urges that gas through the conduit, into the eductor, and into the furnace. Sensors detect when the door is open and the volatiles level under the hood. An electronic controller instructs the blower to draw exhaust gases through the manifold when the door is open and the volatiles level exceeds a predetermined level.