Abstract: Method and apparatus for mixing gases while providing a substantially constant gas-to-gas ratio while increasing or decreasing the flow of the mixture, wherein the flows of gases introduced into the mixing step are turbulent and have a Reynolds number of above about 2000.

Abstract: A low NOx gaseous fuel burner that creates a wall hugging flame, even in a cup. It is comprised of two staged premix units, one unit, in a cup, running very lean and the second unit, extended into the furnace, running very rich, the combination being stoichiometric.

Abstract: A staged, superposition gaseous fuel burner provides substantial reduction of nitrogen oxide content in the combustion gases by providing a transverse turning plate in the burner tip and by staging the delivery rich combustion gases, by introducing premix gaseous fuel in stages spaced with respect to incoming secondary air, thereby exposing the incoming secondary air to spaced stages of the rich mixture.

Abstract: A gaseous fuel burner provides substantial reduction of nitrogen oxide content in the combustion gases by creating a screen of premix combustion products, by introducing secondary gaseous fuel for admixture with the screen, and by exposing secondary air to the mixture for reaction with the secondary gaseous fuel.

Abstract: A controlled primary air inspirating gas burner is provided with a fuel inspirating jet and an induced primary air passageway, with a means forming a separate control primary air passageway, together with means for controlling the introduction of control primary air. The content of nitrogen oxides in the flue gas is substantially reduced by introduction of regulated amounts of control primary air into the burner.

Abstract: A vortex burner is provided in a burner block, having a sleeve spaced within the burner block, the sleeve being shorter than the burner block opening and spaced within such opening to provide a passageway between them. The burner block has an exvoluting cup which creates negative pressure therein, tending to draw cooling air inwardly into the cup, cooling the short sleeve.

Abstract: Sealing means for preventing metal vapor, and in particular zinc vapor, evolution from the surface of a bath into a furnace is provided at the exit end of the heat processing industrial furnace through which a continuous metal sheet is advanced. Upon exiting the furnace the metal sheet is dipped into a bath for hot dip coating thereof. At the zone of the industrial furnace from which the continuous metal sheet exits the furnace and advances into the coating bath, there is provided therein an atmosphere having a low dew point and a relatively high hydrogen content to thereby reduce the oxidation of the metal vapor which may have migrated into the furnace. Furthermore, sealing means are provided between zones of the furnace to retain the integrity of this atmosphere, and thus isolating zones having different atmosphere compositions.