Cast refractory base segments and modular fiber seal system for plural-stack annealing furnace

A set of components that can be positioned atop a base support structure of an annealing furnace for defining a generally annular inner seal that extends concentrically about an imaginary upstanding axis that defines the center of a stack location of the furnace, comprising:

• a) inner cast ceramic refractory segment means 1) for extending concentrically in an annular arrangement about said axis for underlying and supporting portions of a charge support element of the furnace that extends concentrically about said axis for underlying and supporting a coil of metal that is to be treated in a treatment chamber that is defined to extend about the coil of metal when an inner enclosure of the furnace is lowered into place so lower portions thereof extend substantially concentrically about and enclose the charge support element, and 2) for defining a substantially uninterrupted, radially outwardly facing surface that extends substantially concentrically about said axis so as to be surrounded by said lower portions of the lowered-in-place inner enclosure;
• b) outer cast ceramic refractory segment means for defining a substantially uninterrupted, radially inwardly facing surface that extends substantially concentrically 1) about said axis, 2) about said radially outwardly facing surface at a distance spaced therefrom, and 3) about said lower portions of the lowered-in-place inner enclosure so as to cooperate with the inner segment means to define an annular, upwardly opening trough of substantially uniform cross-section as viewed in planes that radiate from said axis its length, into which trough said lower portions of the lowered-in-place inner enclosure extend;
• c) annular seal means formed at least in part from heat resistant ceramic material for being installed in said trough to define a somewhat resilient seal that is engaged by said lower portions of the lowered-in-place inner enclosure and is caused by force applied to the seal due to the seal's being engaged by said lower portions to deform at least slightly to thereby aid in establishing a substantially gas-impervious seal for the treatment chamber;
• d) wherein the radially outwardly facing surface and the radially inwardly facing surface cooperate to define said substantially uniform trough cross-section as being tapered so as to widen progressively as the trough opens upwardly;
• and, e) wherein said annular seal means has a substantially uniform cross-sectional configuration of sufficient radially extending width 1) to ensure that the annular seal means is at least slightly compressed as it is pressed between the radially inwardly and radially outwardly facing surfaces as it is installed into the trough, and 2) to ensure that, if the cross-section of the seal tends to diminish slightly during its service life, the force applied to the seal due to the seal's being engaged by the lowered-in-place inner enclosure will tend to press the seal more deeply into the narrow lower part of the trough where the seal still will have a sufficiently wide cross-section to the bridge between the radially inwardly and radially outwardly facing surfaces.

A base assembly for a plural-stack annealing furnace, comprising:

• a) a welded steel base support structure having a periphery that defines the shape of the base, having a top surface of said shape defined by plate steel with a plurality of spaced blower mount locations in an array spaced centrally inwardly from the periphery of the base;
• b) a blanket of refractory fiber material substantially covering said plate steel top surface;
• c) inner cast ceramic retractor, segment means for defining annular inner portions of a rigid ceramic refractory base, including a plurality of separate sets of cast refractory inner segments positioned atop said blanket of refractory fiber material, with each of said sets of cast refractory inner segments being configured 1) to define a separate associated annular-shape inner portion of the rigid ceramic refractory base for extending substantially concentrically about a separate associated one of said blower mount locations, 2) to underlie and support a separate associated one of a plurality of generally circular charge support structures of the furnace, and 3) to define a separate-associated (one fit plurality sustantially continuous, radially outwardly facing surfaces that each extends substantially concentrically about a separate associated one of the circular charge support structures at a location near the periphery thereof;
• d) outer cast ceramic refractory segment means for defining outer portions of the rigid ceramic refactory base, including a plurality of cast refractory outer segments positioned atop said blanket refractory fiber material and arranged side by side to cooperatively define atop the blanket of refractory fiber an outer region of the rigid ceramic refractory base of said general shape near which an outer furnace enclosure of said general shape can be removably positioned, with subsets of the outer segments each being co-operable to extend about an associated separate one of said annular-shaped inner portions to define arcuate portions of a separate associated, radially inwardly facing surface that extend concentrically about a separate associated one of said radially outwardly facing surfaces so as to cooperate therewith to define opposite, radially spaced sides of an associated inner seal positioning trough for extending circumferentially about a separate associated one of the circular charge support structures of the furnace;
• and,
• c) inner seal means for being positioned in said troughs atop the base support structure of the furnace for defining a plurality of inner seals 1) that each extend in a separate one of said troughs in a substantially uninterrupted manner about the periphery of a separate associated one of the circular charge support structures 2) that each has sufficient structural integrity so as to be capable of supporting at least a portion of the weight of a separate associated open-bottom inner enclosure of the furnace when bottom rim portions of the associated inner enclosure are seated thereatop, and 3) that each is sufficiently resilient to cooperate with the bottom rim portions of the associated seated inner enclosure to form a gas impervious seal for isolating the environment of an associated treatment chamber.

A cast refractory base of generally rectangular shape for an eight-stack annealing furnace having two spaced, parallel extending rows of four stack locations, wherein the base is formed from plurality of individually formed cast refractory segments assembled side-by-side atop a generally rectangular base support structure, comprising:

• a) inner segment means comprising a plurality of generally arcuate-shaped inner segments for extending in an annular manner about spaced center axes of the eight stack locations of the furnace;
• b) outer segment means comprising four corner-defining segments and at least four side-defining segments for bridging between adjacent pairs of the corner segments to define the generally rectangular shape of the perimeter of the cast refractory base;
• and, c) center segment means including a plurality of center segments for bridging centrally among adjacent inner segment sets;
• d) wherein the inner, outer and center segments cooperate to define substantially annular, upwardly opening troughs extending concentrically about the center axes for receiving inner seals that are engaged by inner enclosures of the furnace that each extend about a separate one of the center axes when lowered into operating position to define separate treatment chambers extending about each of the center axes.

A crush-resistant ceramic seal module for insertion into a given length of an elongate, upwardly-opening trough defined between a pair of spaced, opposed surfaces of an annealing furnace base for being engaged by portions of a cover of the furnace to aid in establishing a gas-impervious seal between the furnace base and the cover extending along said given length, comprising:

• a) a plurality of ceramic fiber blocks arranged serially for defining an array of ceramic fiber blocks configured to be inserted into the confines of the upwardly opening trough along said given length thereof;
• with the blocks having transverse widths that are sufficient to bridge the width of the trough at locations within the trough where the blocks are installed, with the blocks being sufficient in number and size to require that the blocks be compressed in directions extending along the length of the trough to be inserted serially into the trough;
• b) reinforcement means including a plurality of relatively thin, perforated metal members interspersed among the ceramic fiber blocks for extending generally transversely within the confines of the trough for enhancing the crush resistance of the resulting seal;
• and,
• c) elongate means extending substantially centrally through the array of ceramic fiber blocks and through such perforated metal members as are interspersed thereamong, and being connected to end structures located at opposite ends of the array for positioning the end structures to compressively sandwich the array of ceramic fiber blocks and interspersed metal members.

A method of assembling from a set of component parts, at a location atop a base support structure of a plural-stack annealing furnace, 1) a rigid ceramic refractory base for extending in substantially concentric, annular relationship about a plurality of spaced blower mounts of the furnace, for underlying and extending perimetrically about a plurality of charge support structures of the furnace that are of generally circular shape and that are configured to overlie the blower mounts to support a plurality of charges of metal that are to be annealed, and 2) a plurality of relatively resilient annular inner seals that extend perimetrically about the charge support structures, atop which inner enclosures of the furnace can be removably seated for defining a plurality of controlled environment treatment chambers within which charges of metal that are positioned atop the charge support structures can be confined for treatment during an annealing process, comprising the steps of:

• a) providing inner segment means including a plurality of sets of cast refractory inner segments, and installing each set of the inner segment means 1) to define a separate associated annular-shaped inner portion of the rigid ceramic refractory base for extending substantially concentrically about a separate associated one of a plurality of blower mounts of a plural-stack annealing furnace, 2) to underlie and support a separate associated one of a plurality of generally circular charge support structures of the furnace, and 3) to define a separate associated one of a plurality of substantially continuous, radially outwardly facing surfaces that each extends substantially concentrically about a separate associated one of the circular charge support structures at a location near the periphery thereof;
• b) providing outer segment means including a set of cast ceramic refractory outer segments, and installing the outer segment means so that the outer segments extend side by side to cooperatively define an outer region of the rigid ceramic refractory base near which an outer enclosure of the furnace can be removably positioned, with smaller groups of the outer segments of the set comprising outer segment sub-sets, with the segments of each sub-set extending about an associated separate one of said annular-shaped inner portions to define arcuate portions of a separate associated, radially inwardly facing surface that extends concentrically about a separate associated one of said radially outwardly facing surfaces so as to cooperate therewith to define opposite, radially spaced sides of an associated inner seal positioning trough for extending circumferentially about a separate associated one of the circular charge support structures of the furnace;
• and,
• c) providing inner seal means including a plurality of separate inner seals, and installing each of the inner seals atop the base support structure of the furnace and in a separate one of said troughs, with the installed inner seals 1) each extending in a substantially uninterrupted manner about the periphery of a separate associated one of the circular charge support structures, 2) each being capable of supporting at least a part of the weight of a separate associated open-bottom inner enclosure of the furnace when bottom rim portions of the associated inner enclosure are seated thereatop, and 3) each being sufficiently resilient to cooperate with the seated to rim portions of the associated inner enclosure to form a gas impervious seal for isolating the environment of an associated treatment chamber.

A method of forming an elongate, upwardly facing seal of given length within an upwardly opening seal-positioning trough of an annealing furnace base, comprising the steps of:

• a) providing a set of substantially identical ceramic fiber blocks that can be positioned in an end-to-end serial array having a non-compressed length that is greater than said given length, with the fibers of refractory material that comprise said blocks being of sufficient length so that, when the blocks are positioned in said array with their fibers extending substantially transversely relative to the length of the array, the serial array will have a transverse width that is slightly greater than is the width of such portions of the trough portions that are to be occupied by the blocks;
• b) providing a plurality of relatively thin, perforated metal members that have lengths that are less than the width of said trough portions;
• c) arranging said blocks to form said array with the thin metal members interspersed to extend among the blocks of the array;
• and,
• d) compressing-lengthwise and installing the array of blocks with metal members interspersed thereamong within said given length of the trough with the metal members extending transversely within the compressed array to enhance the crush resistance of the resulting seal.

A method of building a plural stack annealing furnace base in an off-site facility that is removed from a furnace site where the base is to be installed, wherein the facility has a crane of sufficient lift capacity to pick up at least one of each of the heavier base components which include a base support structure, a plurality of cast refractory inner segments, a plurality of cast refractory outer segments, comprising the steps of:

• a) forming a plurality of welded steel base support structures at the off-site facility, with the base support structures being configured to be assemblable side-by-side define a base support for the furnace;
• b) utilizing a crane of the off-site facility to individually lift the welded steel base structures onto flat bed vehicle means parked at the off-site facility;
• c) forming cast refractory base assemblies by installing atop each of the base structures separate associated sets of cast refractory inner segments and separate associated sets of cast refractory outer segments;
• d) moving the flat bed vehicle means from the off-site facility to a furnace location where the cast refractory base assemblies are to be installed;
• e) utilizing a crane at the furnace location to connect with the welded steel base structures to lift the welded steel base structures together with the cast refractory base assemblies formed thereon from the flat bed vehicle means to position the welded steel base structures side-by-side at the furnace location.

A method of carrying out an annealing process in a closed, controlled environment of a plural-stack annealing furnace, comprising the steps of:

• a) providing a plural stack annealing furnace, including the steps of providing a base, providing a plurality of removable, open-bottom inner covers configured to cooperate with the base and to extend upwardly therefrom to define a plurality of side by side treatment chambers within which charges of metal can be simultaneously received and contained for being subjected to an annealing process, providing furnace structure configured to extend about the inner covers to provide heat energy for heating the contents of the treatment chambers during an annealing process, and providing seal means 1) connected to the base, 2) extending perimetrically and continuously about bottom regions of the treatment chambers, and 3) being configured to be compressively engaged by substantially continuous bottom rim portion of the open-bottom inner covers when the inner covers are positioned to cooperate with the base to define said treatment chambers i) for supporting at least a portion of the weight of the inner covers atop the base, and ii) for establishing seals between the base and the inner covers that will permit closed, controlled environments of desired character to be maintained within the treatment chambers during annealing of charges of metal contained therein;
• b) supporting separate charges of metal on the base at locations within each of the treatment chambers for being annealed;
• c) positioning the inner covers to extend about the base-supported charges of metal, with the bottom rim portions of the inner covers compressively engaging the seal means so as to establish seals between the base and the inner covers that isolate the environments of the treatment chambers, with the base and the inner covers cooperating to house the base-supported charges of metal within the isolated environments of the treatment chambers;
• d) heating the base-supported, chamber-housed charges of metal within the isolated environment of the treatment chambers to initiate an annealing process of desired character while maintaining a gas atmosphere of desired character within the treatment chambers, and completing the conduct of the annealing process by continuing to control the treatment chamber environments;
• e) withdrawing the inner covers from compressive engagements with the inner seals and from positions wherein the covers surrounded the charges of annealed metal so that the charges of annealed metal can be removed from atop the base;
• f) wherein the step of providing a base includes the steps of:
• 1) providing inner base structure that defines a plurality of spaced, upwardly facing support surface locations for receiving and supporting the charges of metal that are to be annealed, and that defines about each of said locations an associated outer surface which extends perimetrically about its associated charge support location;
• 2) providing outer base structure that extends about the inner base structure, and that defines a separate substantially continuous inner surface to extends perimetrically about and to face generally toward each of the outer surfaces of the inner base structure at substantially uniform distances therefrom so as to define seal mounting troughs of substantially uniform width that extend continuously about the charge support locations, into which troughs the substantially continuous bottom rim portions of the open-bottom inner covers will extend when the inner cover is positioned to cooperate with the base to define said treatment chamber;
• g) wherein at least a selected one of the steps of providing inner base structure and providing outer base structure includes the step of separately forming a plurality of cast refractory base components, and assembling said cast refractory base components to define major portions of such base structure.