US 4,165,865 AGranted

Crucible melting furnace

AssigneeHolcroft & Company

InventorsLeonard G. Nowak, Maurice Nunes, Paul K. Shefsiek

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Abstract

A crucible furnace for high-temperature melting of metals or other materials which includes a capped vessel for serving as a crucible to hold a charge of material to be melted, a solid baffle surrounding and closely spaced from the vessel to form a restricted passageway and a refractory wall surrounding and widely spaced from the baffle to form a combustion chamber. Fuel is supplied at the base of the combustion chamber and mixed with air preheated by a compact internal recuperator operative from exhaust gases exiting the restricted passageway. The fuel is burned in the combustion chamber, heating the baffle which in turn radiates heat to the vessel containing the charge. Several of the elements forming the combustion and heat transfer system also serve as structural elements providing rigid support to internal components when the furnace is upright and when it is tilted to pour off melt. Adjacent its top, openings are formed through the baffle to permit flame and combustion products to pass from the combustion chamber downwardly through the restricted passageway and recuperator region to the exhaust flue. Thus, heating of the vessel is also had by convection. The combustion chamber is isolated from the charge in the vessel by a seal, the integrity of which is maintained by downward pressure from a lip formed on the crucible.

Claims5

Dependent claims

A gas-fired crucible furnace for high-temperature melting of material comprising:

a vessel for holding a charge of said material and having a mouth for admitting and discharging the charge of material;
a baffle surrounding said vessel spaced relatively close thereto and forming a restricted passageway therebetween, said baffle having one or more openings formed therethrough surrounding said vessel adjacent said mouth;
an enclosing wall surrounding said baffle and spaced relatively far therefrom;
a top member sealed to the outer surface of said vessel adjacent to said mouth and to said wall, said baffle, enclosing wall, and top member together defining a combustion chamber;
a swirler disposed between said baffle and said enclosing wall adjacent a portion of said baffle remote from said one or more openings therethrough, said swirler adapted to introduce combustion air into said combustion chamber in a helical path;
a cylindrical swirler support for supporting said swirler and said baffle and defining with said enclosing wall a combustion air plenum on the side of said swirler opposite said combustion chamber;
an exhaust flue communicating with said restricted passageway;
a cylindrical member supporting said vessel concentric with said swirler support and defining therewith an annular region between and in communication with said restricted passageway and said exhaust flue, said annular region in heat exchange relationship with said swirler support and said air plenum for preheating combustion air in said plenum;
and
means for introducing gas for combustion into said combustion chamber whereby said vessel is radiatively heated from said baffle and convectively heated from the passage of combustion products through said restricted passageway to said exhaust flue.

7 more elements

Dependencies are inferred from the claim text.