Disclosed is a kiln having a portion with which raw materials for preparing active materials and/or the prepared active materials come into contact during firing, the portion containing a substance represented by the following Formula 1:

Ni.sub.aX.sub.z (1) wherein a and z are weight fractions satisfying 0.85?a<1 and 0<z?0.15, respectively; and X includes at least one element selected from the group consisting of Cr, Fe, Co, Mn, P, Cu, Mo, Si, Nb, Ti, W, C, Na, Al, Mg, Zn, B, Ta, O, Sn, Ag, Re, Ru and Zr, or an alloy or compound of at least two elements selected therefrom.

A vacuum double structure includes: a tubular and metal inner wall member; a tubular and metal outer wall member in which the inner wall member is accommodated; and a sealing member provided between a facing surface of the inner wall member and a facing surface of the outer wall member. The sealing member includes an annular spacer, a first annular packing material, and a second annular packing material. The annular spacer is provided between the facing surface of the inner wall member and the facing surface of the outer wall member.

Provided is a vacuum beat insulation structure for a heating furnace having a beating space covered by an inner cylinder serving as an inner wall, and an outer cylinder serving as an outer wall configured to cover the inner cylinder, and a vacuum space formed between the inner cylinder and the outer cylinder, the vacuum heat insulation structure including a reflective film disposed in the vacuum space and configured to prevent transfer of radiant heat from the inner cylinder to the outer cylinder in the vacuum space, and a fixing tool configured to fix the reflective film to an inner surface of the outer cylinder so as not to come in contact with an outer surface of the inner cylinder.

A heater assembly with enhanced cooling pursuant to various embodiments described herein makes use of fluidic flow in the insulation or in the space used for insulation. By creating a natural convection or forced convection flow, the heater cools down faster, it can operate at lower temperatures and/or higher temperature precision, and it can improve temperature controllability by generating higher heat loss rates.

A heater assembly with enhanced cooling pursuant to various embodiments described herein makes use of fluidic flow in the insulation or in the space used for insulation. By creating a natural convection or forced convection flow, the heater cools down faster, it can operate at lower temperatures and/or higher temperature precision, and it can improve temperature controllability by generating higher heat loss rates.

A heater assembly with enhanced cooling pursuant to various embodiments described herein makes use of fluidic flow in the insulation or in the space used for insulation. By creating a natural convection or forced convection flow, the heater cools down faster, it can operate at lower temperatures and/or higher temperature precision, and it can improve temperature controllability by generating higher heat loss rates.

A heater assembly with enhanced cooling pursuant to various embodiments described herein makes use of fluidic flow in the insulation or in the space used for insulation. By creating a natural convection or forced convection flow, the heater cools down faster, it can operate at lower temperatures and/or higher temperature precision, and it can improve temperature controllability by generating higher heat loss rates.

A heat treatment apparatus includes: a heat treatment chamber that performs heating treatment for a treatment object thereinside; and a thermal insulator disposed inside the heat treatment chamber and surrounding a receiving area for the treatment object. The heat treatment chamber includes a side wall portion and a lid portion configured to be attachable to and detachable from the side wall portion. The thermal insulator includes a ceiling disposed on the inside of the lid portion. The ceiling includes a thermal insulator lid that is at least part of the ceiling and is united to the lid portion.

A heat treatment apparatus includes: a heat treatment chamber that performs heating treatment for a treatment object thereinside; and a thermal insulator disposed inside the heat treatment chamber and surrounding a receiving area for the treatment object. The heat treatment chamber includes a side wall portion and a lid portion configured to be attachable to and detachable from the side wall portion. The thermal insulator includes a ceiling disposed on the inside of the lid portion. The ceiling includes a thermal insulator lid that is at least part of the ceiling and is united to the lid portion.

A furnace system including an outer shell which comprises a top flange, an elongated body portion, and a bottom flange, wherein the outer shell is a pressure vessel, with no penetrations in the elongated body portion; a heater assembly which comprises (i) a single-piece annular shaped insulation layer, and (ii) a plurality of heaters embedded in the insulation layer, wherein the heater assembly is disposed within the elongated body portion of the outer shell; and an innermost layer disposed within the annular-shaped insulation layer, wherein the innermost layer is a baffle tube configured to force a natural convective flow, wherein each of the plurality of heaters is individually controllable and the plurality of heaters are configured to heat different zones within the furnace to different temperatures and/or at different rates. The system may be used to heat treat magnet materials, such as those formed of Bi-2212, therein.