A shuttle kiln (100) according to certain aspects includes at least one flue channel (124) and multiple flue risers (122) in fluid communication with the flue channel (124), and at least one shuttle (104) defining multiple exhaust shafts (140) arranged above the multiple flue risers (122), wherein an aggregate volume of a first exhaust shaft/riser pair (140-1, 122-1) differs from an aggregate volume of a second exhaust shaft/riser pair (140-2, 122-2). Such configuration at least partially compensates for different backpressures that would otherwise be experienced by flue gas exiting a shuttle kiln cavity (138) through different exhaust shafts (140), thereby improving uniformity of flue gas flow and reducing temperature variability within a kiln cavity (138).

A shuttle kiln according to certain aspects includes at least one flue channel and multiple flue risers in fluid communication with the flue channel, and at least one shuttle defining multiple exhaust shafts arranged above the multiple flue risers, wherein at least one radiation blockers is arranged above outlet ports of the at least one shuttle. Such a configuration blocks line-of-sight radiant heat transfer between (i) heated surfaces above the shuttle within the kiln housing and (ii) outlet ports of the exhaust shafts, thereby enhancing radiant heat retention and reducing temperature variability within a kiln cavity of the shuttle kiln.

A roller for a roller hearth furnace, the roller including a water-cooled, rotatably mounted carrying axle on which a plurality of support rings are arranged at a spacing from one another. In the axial region between and next to the support rings, the carrying axle is provided with insulation composed of a fiber material and configured with protection of the outer circumference of the fiber material from the environment. In the case of insulation constructed from ring-shaped punched parts, the insulation arranged in the axial region between and next to the support rings is composed of circular or ring-shaped punched fiber parts. The protection is configured as ring-shaped insulating disks composed of a more resistant material than that of the punched fiber parts, and at least one punched fiber part is provided in each case between two insulating disks.

A furnace roller assembly having a fluid-cooled shaft that is covered by an interface performance material comprising both ceramic millboard and a wire brush bristled-material is disclosed. The roller assembly can be used as part of a conveyance system in a finishing mill to support and transport steel sheet through an annealing furnace. The fluid-cooled shaft and the ceramic millboard plus wire brush interface performance material arrangement provide the means to provide effective insulation for the shaft while preventing degradation of the covering on the shaft.

A method of manufacturing a permanent magnet comprises a solution heat treatment. The solution heat treatment includes: performing a heat treatment at a temperature T.sub.ST; placing a cooling member including a first layer and a second layer on the first layer between the heater and the treatment object so that the first layer faces the treatment object; and transferring the treatment object together with the cooling member to the outside of a heating chamber, and cooling the treatment object until a temperature of the treatment object becomes a temperature lower than a temperature T.sub.ST200 C. In the step of cooling the treatment object, a cooling rate until the temperature of the treatment object becomes the temperature T.sub.ST200 C. is 5 C./s or more.

A roller for a roller hearth furnace, the roller including a water-cooled, rotatably mounted carrying axle on which a plurality of support rings are arranged at a spacing from one another. In the axial region between and next to the support rings, the carrying axle is provided with insulation composed of a fiber material and configured with protection of the outer circumference of the fiber material from the environment. In the case of insulation constructed from ring-shaped punched parts, the insulation arranged in the axial region between and next to the support rings is composed of circular or ring-shaped punched fiber parts. The protection is configured as ring-shaped insulating disks composed of a more resistant material than that of the punched fiber parts, and at least one punched fiber part is provided in each case between two insulating disks.

A method of manufacturing a permanent magnet comprises a solution heat treatment. The solution heat treatment includes: performing a heat treatment at a temperature T.sub.ST; placing a cooling member including a first layer and a second layer on the first layer between the heater and the treatment object so that the first layer faces the treatment object; and transferring the treatment object together with the cooling member to the outside of a heating chamber, and cooling the treatment object until a temperature of the treatment object becomes a temperature lower than a temperature T.sub.ST200 C. In the step of cooling the treatment object, a cooling rate until the temperature of the treatment object becomes the temperature T.sub.ST200 C. is 5 C./s or more.

A shuttle kiln (100) according to certain aspects includes at least one flue channel (124) and multiple flue risers (122) in fluid communication with the flue channel (124), and at least one shuttle (104) defining multiple exhaust shafts (140) arranged above the multiple flue risers (122), wherein an aggregate volume of a first exhaust shaft/riser pair (140-1, 122-1) differs from an aggregate volume of a second exhaust shaft/riser pair (140-2, 122-2). Such configuration at least partially compensates for different backpressures that would otherwise be experienced by flue gas exiting a shuttle kiln cavity (138) through different exhaust shafts (140), thereby improving uniformity of flue gas flow and reducing temperature variability within a kiln cavity (138).