Abstract: The invention relates to a method for treating metal strip in a directly fired furnace through which the metal strip is guided. The furnace is fired directly by gas burners and has a non-fired zone through which the exhaust gases from the fired zone flow and thus heat the metal strip. After leaving the non-fired zone, the exhaust gases from the furnace undergo post-combustion in an afterburner chamber. According to the invention, methane is injected into the non-fired zone, which causes nitrogen oxides contained in the waste gas to be converted into hydrogen cyanide.

Abstract: An apparatus is disclosed for a split spray-cooled roof for a tilting metallurgical furnace. The split spray-cooled roof has a center, a first hollow metal roof section and a second hollow metal roof section. The first and second hollow roof sections are attached together along a prescription split line. The prescription split line having a first split line and a second split line, wherein the first split line is not aligned with the second split line and wherein the first and second split line are not aligned with the center.

Abstract: An apparatus is described for bracing of sheet-metal joints (1) in a high-temperature annealing furnace having at least one carrier (2), which frontally receives a sheet-metal joint (1) and has a central axial passage opening (6), on which a support pipe (5), which axially penetrates the sheet-metal joint (1), having a carrier (2) for receiving a further sheet-metal joint (1) can optionally be placed in a load-bearing manner. In order to provide advantageous heating conditions, it is proposed that the carrier (2) has a ring body (7) forming the passage opening (6), having radially protruding carrier arms (8) distributed around the circumference.

Abstract: A diffuser (24) for an annealing furnace has a plurality of radially extending generally and vertically oriented vanes (40) for radially directing furnace gases. The vanes have top edges (42) defining a generally planar support and the top edges of the vanes have a notch (38) therein for receiving a conduit (34) preferably ring shaped that extend substantially around a center portion of the diffuser plate. The conduit (34) is connected to an inlet (32) for receiving enriching gases and exit ports (50) circumferentially space about said conduit (34) passing the enriching gases into the diffuser (24) to be mixed with ambient furnace gases.

Abstract: A support slug (2) used for the heat treatment of a part (3), particularly for the hardening of a steel part, comprises a guide element (221) that is used to guide the part (3) towards a supporting surface (230) of the support slug (2) when said part is being positioned on the support slug. A ceramic element (23) including the supporting surface (230) is embedded in the metal body (20) of the support slug.

Abstract: An apparatus and a method for suppressing growth of an oxide film on a coil which is a spirally wound, rolled strip are disclosed. A rolled strip subjected to rolling by hot rolling equipment is wound spirally by a down-coiler to make a coil. Covers are disposed on the opposite sides of the coil such that heat resistant materials intimately contact the opposite sides of the coil. The covers are fixed by L-bolts and nuts to cover the opposite sides of the coil with the covers. In this state, the coil is naturally cooled for a predetermined time to suppress growth of an oxide film and increase productivity.

Abstract: An annealing furnace inner cover cooperates with a furnace base to define a treatment chamber within which a charge of metal such as steel is housed for annealing, wherein the inner cover carries at least one interior cooling conduit through which cooling water from an exterior source is circulated to expedite the cooling of gas that is circulated within the treatment chamber during cooling portions of an annealing cycle. The water cooled inner cover is especially well suited for expediting the cooling of stacked coils of steel sheet from an annealing temperature, and preferably utilizes a helix of cooling coils that surround mid-height portions of the stack, wherein the cooling coils are protectively housed within an inwardly facing recess defined by an enlarged diameter mid-height portion of the inner cover both to prevent cooling coil damage due to impact during cover movement, and to ensure that gas circulation within the inner cover is not adversely restricted by the presence of the cooling coils.

Abstract: An improved convector plate is provided for a batch coil annealing furnace. The plate includes a top annular plate, an identical bottom annular plate and an annular diverter plate in between. A plurality of slotted openings are provided in the top and bottom plates which extend radially outwardly from a first imaginary circle spaced from the inner peripheral edge of the top and bottom plates to an imaginary second circle spaced inwardly from the top and bottom plate's outer peripheral edge. The annular diverter plate is radially centered within the slotted openings. When the convector plate is placed between the edges of two coils, furnace atmosphere flows into the convector plate in the space between the top and bottom plates and is directed by the diverter plate into the slotted openings which are now covered by the coil edges thus establishing improved convective heat transfer rates with the coil edges resulting in shorter annealing process times.

Abstract: The present invention provides an inexpensive furnace modification which increases the productivity of the furnaces without requiring extensions to the furnace member or the surrounding building. Existing inner covers are extended a predetermined amount to accommodate the additional steel product within the volume defined by the inner cover. This is done by either adding a section to an existing inner cover, or by providing new covers of increased height. A ring structure of the predetermined additional height required and having the same diameter as the furnace member is placed over the inner cover and positioned to rest on the furnace base so that it encircles a portion of the inner cover. The furnace member is then placed over the inner cover and positioned to rest on the ring. Preferably, both the ring and the furnace member have annular locating lugs which coact with locating posts adjacent the base.

Abstract: A convection diffuser and charge support system for an annealing furnace utilizes a diffuser base assembly to support a stack of coiled rolls of steel that are to be annealed inside a furnace enclosure. The coils are arranged in a vertical stack atop the base assembly. The furnace enclosure surrounds the base assembly and the stack to provide a "closed" treatment environment. Convector plates are interposed between the ends of the coils, with a separate convector plate extending horizontally between each set of adjacent coil ends. Each of the convector plates includes an annular structure 1) that has an inner diameter, 2) that has an outer diameter that extends substantially concentrically about the inner diameter, and 3) that defines a plurality of radially extending air flow passages which extend from locations near the outer diameter to locations near the inner diameter for assisting in providing a desired type of convection flow of gases within the furnace enclosure.

Abstract: This invention relates to an apparatus and method for retaining the configuration of an aperture formed through a coil when the coil is supported on a saddle. The saddle has a pair of spaced apart upstanding legs. The apparatus includes a first and a second member, with the second member having a length sufficient to span the legs of the saddle. A pair of arms are pivotably attached to the first member and the arms are joined to the second member by a pair of links. The links enable the arms to move between a first position in which the arms are spaced inward and apart from the perimeter of the aperture when the second member is not in contact with the legs of the saddle and a second position in which the arms cooperate with the first member to support the weight of the coil when the second member is in contact with the legs of the saddle. The apparatus is particularly useful for supporting a coil during a heat treatment operation.

Abstract: Disclosed is a coil-annealing spacer which comprises a pair of upper and lower discs, each having a round hole in the central portion thereof, and longitudinal ribs disposed between the discs and secured thereto and extended radially or spirally radially from the round hole of each disc toward the periphery, wherein heat transfer fins are arranged on the inner wall of a gas passage defined by said upper and lower discs and said longitudinal rib along the flow of an atmosphere gas.If this coil-annealing spacer is used, the heating/cooling time is shortened at the annealing step to enhance the manufacturing capacity, and the deviation of the quality in the product coil is reduced.

Abstract: A convection diffuser and charge support system for an annealing furnace utilizes a diffuser base assembly that includes a vane-carrying center casting which underlies a charge support plate, and which is perimetrically surrounded by a pair of outer and inner cooling rings. The components of the diffuser base assembly cooperate to define an array of horizontally extending gas circulation passages that are shielded from above by the charge support plate. The horizontal passages extend among a plurality of upstanding heat exchange fins that are carried by the inner cooling ring, and terminate in upwardly extending outer end regions that are defined by grooves formed in the outer cooling ring. A centrifugal fan draws hot gases through a central opening in the charge support plate and conveys the gases radially outwardly through the horizontally extending gas flow passages.

Abstract: A convection diffuser and charge support system for an annealing furnace utilizes a diffuser base, a base-encircling ring, and convector plates which are preferably formed as castings of nodular iron. The diffuser base defines an array of horizontally-extending gas circulation passages which are shielded from above by an integrally-formed, overlying top wall. The top wall prevents debris and other undesirable substances from dropping into and accumulating within the primary flow passages. Vane extension formations project above the top wall and have their upper edges arranged to engage and support a charge of material to be annealed. The ring structure extends perimetrically about the base structure and defines an array of curved, upwardly opening grooves which cooperate with the primary flow passages to direct gases which discharge from the base structure so that the gases flow upwardly, along a generally helical flow paths about a charge of material being annealed.

Abstract: A load support diffuser adapted to support a vertical stack of coils in an annealing furnace and means for cooling a protective atmospheric gas within said furnace, the diffuser comprising a flat circular base plate, a plurality of outer load support members secured to spaced portions of the outer periphery of the base plate, a flow deflecting ramp disposed between each pair of adjacent spaced outer load support members, spaced vertical radial inner load support members spaced inwardly on the base plate from the outer load support members, a cooling member disposed in an annular space provided in the diffuser between said outer and inner support members.

Abstract: This invention provides a spacer for vertically separating coils in an annealing furnace. The spacer includes a lower segmental plate and an upper segmental plate, and ribs between the segmental plates and affixed thereto. A porous medium is disposed between the segmental plates, so that the porous medium can be heated by hot gas passing through it, and can then radiate heat to the inside surfaces of the segmental plates.

Abstract: The invention provides a loading system for the charge of an annealing furnace of the kind intended for the treatment of a stack of coils mounted one on top of the other with their central cores in register with one another, a protective heat exchange gas atmosphere being circulated around the stack within a cylindrical bell-shaped muffle cover to heat and subsequently cool the charge. The system comprises a diffuser member having a gas impeller at its center that receives gas passing downwards through the coil cores and discharges it radially into the annular space between the stack and the muffle cover in a preferred helical path. The stack rests on a load member placed on the diffuser member, a convector plate is interposed between each pair of superimposed coils and the stack is completed by a top member and a plug member.

Abstract: The present invention is a method and apparatus for heat treating at least one work item, such as a coil, having an axial passage and being axially stacked on a base support means disposed within a cover means which is located on the base support means. The base support can be on the floor of a furnace and with the chamber of the furnace. A means to force the atmosphere such as an axial fan is located in the base. The atmosphere is forced axially from the base, up through an axial path including the axial passage of the at least one coil, through a top space between the top of the stack of coils and the top of the cover means, down through the annular space between the outside of the coils and the inside of the cover means, and back to the axial path through a base space beneath the at least one coil, communicating from the annular space to the axial path.

Abstract: A diffuser adapted for transmitting thermal energy by conduction across metallic members and by convection of a heat-treating gas in an annealing furnace is comprised of a base, a diffuser member having a plurality of radial gas passages, and an in-line cooling member disposed longitudinally within each of the radial passages; which cooling member includes a cooling fluid inlet, at least one radial cooling fluid leg having a longitudinal axis extending substantially in the direction of the gas flow through the radial passage, and a cooling fluid outlet.

Abstract: Coils of strip to be annealed are placed in a furnace with their eye vertical and are heated to the annealing temperature by heating elements on the furnace above and below the level of the coils. An improved convector coil support includes a single metal plate having a central opening and grooves in one side extending from the central opening to the outer periphery when used to support a bottom coil and two such plates fastened together with their grooves facing each other when the convector is used to support a coil on top of a coil.

Abstract: A support for a workpiece to be heated, the support comprising a laminate of metal strip arranged in face-to-face relation with the adjacent normally upper strip edges forming a support surface.

Abstract: Apparatus and process are disclosed whereby open coils having spaces between the convolutions may be treated in a longitudinally extending furnace by passage of treating gases between the convolutions of the coils, the coils being introduced at one end of the furnace, passed through the furnace while being treated, and removed from the other end of the furnace. Walking beam apparatus is disclosed having sealing means, disclosed as a trough and flange sealing means that prevents gas leakage between the lower portion of the walking beam apparatus and the atmosphere, so that a completely gas sealed enclosure may be provided above the walking beams. Transfer means are disclosed at the entrance and discharge ends of the furnace, for introducing coils into the furnace and removing them from the furnace through purge chambers. A coil support that travels with the coil through the furnace is disclosed. Processes are also disclosed for continuously treating open coils.

Abstract: Apparatus for and process of heat treating open coils of strip metal, such as strip steel, by passing hot gases or atmospheres through spaces between spaced convolutions of the coil, in which a shielding structure is provided at the upper end of the coil where the coil edge portions are exposed to radiant heat from the furnace and where they may tend to move and distort from gas velocity or localized thermal expansion. The shielding structure protects these portions of the coil from excessive heat and restricts harmful movement thereof, thus improving the quality of the heat treated product. The disclosed shielding structure comprises spaced upwardly extending walls the height of which is sufficient to, and the spacing of which is such as to, prevent direct impingement of radiant heat on the upper end of the coil while permitting adequate flow of gas through the shielding structure for treating purposes.

Abstract: A method and means for the high temperature annealing of metallic coils whereby a coil to be annealed is held, with its axis in a horizontal position, in the annealing furnace by support means passing through the eye of the coil. The support means comprises a horizontal member passing through the eye of the coil and means to support the horizontal member in such a way that the coil contacts only the horizontal member.

Abstract: In an annealing furnace of the type comprising an outer enclosure surrounding an insulated heating chamber and wherein the bottom of the heating chamber comprises a metallic coil carrying car having one or more base plates upon which the coils of metal to be annealed are supported and having electrical heating elements beneath the base plates, improved means for supporting the one or more base plates on the coil carrying car. The support means for each base plate comprises a plurality of refractory blocks mounted on the upper surface of the car and upon which the base plate rests. The refractory blocks are so arranged as to accommodate the heating elements beneath the base plate and to permit the circulation of an atmosphere thereabout, while at the same time affording maximum support for the base plate.