Water cooled inner cover for annealing furnace

Apparatus for cooling from an annealing temperature a generally cylindrical stack of coils of sheet steel that each have a generally cylindrical outer surface and opposed, substantially flat sides, that are supported atop a base of an annealing furnace with opposed sides of each of the coils extending substantially horizontally, and with the coils of the stack extending substantially coaxially one atop another with an uppermost portion of the highest coil in the stack defining the height of the stack, comprising:

• a) inner cover means for surrounding the stack of coils and for cooperating with the base of the annealing furnace to define a generally cylindrical treatment chamber sealed from ambient atmosphere within which gases of a nonoxidizing atmosphere may be circulated;
• b) cooling conduit means connected to the inner cover means for being positioned within the treatment chamber to encircle at least one circumferentially extending portion of the cylindrical outer surface of at least one coil of the stack at a location mid-way along the height of the stack and at a distance separated from said at least one portion by a space that also encircles said at least one portion, and with the cooling conduit means having inlet means and outlet means for the flow of coolant fluid through the cooling conduit means for cooling the cooling conduit means for cooling gases of the nonoxidizing atmosphere that circulate within the treatment chamber and through said space;
• and,
• c) protective means for minimizing damage to the cooling conduit means by minimizing contact of the cooling contact means with the stack when the inner cover means is positioned to extend about, and is withdrawn from extending about, the stack.

An annealing furnace for heating to an annealing temperature and for cooling from an annealing temperature a mass of steel that includes at least one coil of sheet steel having a generally cylindrical outer surface and opposed, substantially flat sides, that is supported atop a base of an annealing furnace with the opposed sides of the coil extending substantially horizontally, comprising:

• a) generally cylindrical inner cover means for surrounding the mass of steel and for cooperating with the base of the annealing furnace to define a generally cylindrical treatment chamber sealed from ambient atmosphere within which gases of a nonoxidizing atmosphere may be circulated;
• b) heating means for heating the mass of steel within the treatment chamber to a selected annealing temperature;
• c) cooling means for cooling the mass of steel from the selected annealing temperature including cooling conduit means connected to the inner cover means for being positioned within the treatment chamber to encircle at least one circumferentially extending portion of the cylindrical outer surface of said at least one coil at a distance separated therefrom by a space that also encircles said at least one portion, and with the cooling conduit means having inlet means and outlet means for the flow of coolant fluid through the cooling conduit means for cooling the cooling conduit means for cooling gases of the nonoxidizing atmosphere that circulate within the treatment chamber and through said space;
• and,
• d) protective means for minimizing damage to the cooling conduit means by minimizing contact of the cooling conduit means with the mass of steel when the inner cover means is positioned to extend about, and is withdrawn from extending about, the mass of steel including an enlarged diameter mid-height region of the inner cover wherein the cooling means is protectively nested.

A method for cooling from an annealing temperature a mass of steel that includes at least one coil of sheet steel having a generally cylindrical outer surface and opposed, substantially flat sides, that is supported atop a base of an annealing furnace with the opposed sides of the coil extending substantially horizontally, comprising the steps of:

• a) providing inner cover means for surrounding the mass of steel and for cooperating with the base of the annealing furnace to define a generally cylindrical treatment chamber sealed from ambient atmosphere within which gases of a nonoxidizing atmosphere may be circulated, with the inner cover means including recess defining means for defining a circumferentially extending recess that extends about and faces toward the at least one portion of the cylindrical outer surface of said at least one coil;
• b) providing cooling conduit means connected to the inner cover means for being positioned within the treatment chamber, with at least portions of the cooling conduit means extending into the recess for being protectively enclosed therein, to encircle at least one circumferentially extending portion of the cylindrical outer surface of said at least one coil at a distance separated therefrom by a space that also encircles said at least one portion, and with the cooling conduit means having inlet means and outlet means for the flow of coolant fluid through the cooling conduit means for cooling the cooling conduit means for cooling gases of the nonoxidizing atmosphere that circulate within the treatment chamber and through said space;
• and,
• c) circulating coolant fluid through the cooling conduit means to cool cooling gases circulating within the treatment chamber to assist in cooling the mass of steel after the mass of steel has been heated to an annealing temperature.