Vapor-Reinforced Expanding Volume of Gas to Minimize the Contamination of Products Treated in a Melting Furnace

A heating system comprising:

• a open vessel for containing molten metal, the vessel including a bottom wall, a side wall, and an opening;
• an inert cryogen source, the inert cryogen including a liquid flow component and a vaporous flow component;
• a delivery system disposed proximate the opening, the delivery system comprising:
• a lance including an inlet and a outlet, wherein the inlet is connected to the inert cryogen source;
• a hood coupled to the outlet of the lance, wherein the hood directs the components of the inert cryogen toward the molten metal,
• wherein the hood is configured to direct the liquid component of the inert cryogen toward the bottom wall of the vessel such that the liquid component contacts the molten metal to form an expanding volume of gas having a rate of expansion, and
• wherein the hood is further configured to direct the vaporous component toward the molten metal to inhibit the rate of expansion of the expanding volume of gas.

A heating system comprising:

• an open vessel for containing molten metal, the vessel including a bottom wall, a side wall, and an opening;
• a source of inert cryogen, the inert cryogen including a liquid flow component and a vaporous flow component;
• a delivery system disposed proximate the opening, the delivery system comprising:
• a lance including an inlet and a outlet, the inlet being connected to the inert cryogen source;
• a means for receiving the inert cryogen from the lance and for directing the liquid component of the inert cryogen toward the bottom wall of the vessel such that the liquid component contacts the molten metal to form an expanding volume of gas having a rate of expansion, wherein the means for receiving inert cryogen is further configured to direct the vaporous component toward the molten metal to inhibit the rate of expansion of the expanding volume of gas.