Fluid-cooled needle for molten material flow control

A molten material furnace system having a liquid cooled flow control mechanism and method are disclosed. In particular, the flow control mechanism can include a needle including: a longitudinal axis; an outer conduit including an outer base end, an outer body, and an outer free end; an inner conduit including an inner base end, an inner body radially spaced from the outer body, an inner free end, and a central inlet passage extending between the inlet and the inner free end. Also disclosed is a needle control assembly to position the flow control needle relative to a stilling tank outlet orifice to control flow of molten material through the outlet orifice.