Atomizing nozzle assembly for making metal powder and method of operating the same

Claim 1

Apparatus for atomizing a stream of molten metal, comprising means forming a reservoir for molten metal to be atomized, a metal-transmitting nozzle, means supporting said metal-transmitting nozzle with its intake end extending a predetermined distance into and communicating with said reservoir, said metal-transmitting nozzle having a short metering orifice formed at its intake end and having a length substantially equal to said predetermined distance with the ratio of its length to the diameter of said metering orifice being equal to about 1, said metal-transmitting nozzle having a discharge passage merging at its upper end with said metering orifice, said discharge passage being substantially longer than said metering orifice, said metal-transmitting nozzle at its discharge end terminating in an annular land extending in a plane normal to the axis of said discharge passage and at the end of the latter, the walls defining said discharge passage being downwardly divergent from said metering orifice to said land, means for forming a substantially hollow stream of molten metal at the discharge end of said metal-transmitting nozzle for drawing the molten metal substantially radially outward over said land with part of the metal coating the peripheral portion of said metal-transmitting nozzle from said annular land to the bottom of an annular wall portion and including means forming an annular atomizing fluid orifice surrounding the discharge end portion of said metal-transmitting nozzle with the exit opening of said orifice spaced above said land, and said last mentioned means forming said annular wall portion with the latter separating said atomizing fluid orifice and the discharge end portion of said metal-transmitting nozzle and extending below the exit opening of said atomizing fluid orifice toward said annular land.