Chute with hazardous flame and fume control

An apparatus for making alloy additions to molten metal in a vessel, said apparatus including a tubular chute having an upper entry opening for receiving alloy additions and a lower discharge opening adapted to be located adjacent the vessel, said chute having a tendency to act as a chimney for hot gases when molten metal is in a vessel adjacent the lower discharge opening, the improvement comprising a plurality of directional inlet openings into the chute equally spaced peripherally and located beneath the upper entry opening, oriented to direct a flow of gas into the chute each at the same angle between 30.degree. and 60.degree. from a transverse plane perpendicular to a central longitudinal axis of the chute in a direction toward the discharge opening and non tangential to the chute periphery, and a manifold for connecting said inlet openings to a source of gas under pressure, said manifold having a capacity to carry a greater flow than that of the combined inlet openings to assure substantially uniform pressure and flow at the inlet openings.

In a method of making additions to molten metal, including the steps of pouring molten metal into a vessel, introducing additions into the metal during pouring by dropping the additions through a tubular chute extending from a level substantially above the vessel to a level adjacent and above an opening to the vessel, said chute having open upper and lower ends and tending to act as a chimney up which hot gases flow from the vessel, the improvement comprising introducing gas into the chute, concurrently with the additions, between the open ends at locations peripherally of the chute, at sufficient pressure and in sufficient quantity to create a downward flow of gas through the chute that prevents upward flow of hot gases and that reduces the pressure at the open upper end of the chute to below ambient pressure.