A kiln for firing ceramic slabs (T) comprising: a heating module (2), a firing module (3), a cooling module (4), consecutively connected to each other along an advancement direction (Y) of the slabs (L), which define a process chamber (C) provided with an inlet opening (A) and an outlet opening (B); a transport system (T1, T2) arranged along the process chamber (C) from the inlet opening to the outlet opening, structured to transport the slabs (L) along the advancement direction (Y) the process chamber (C) comprises at least a first channel (C1) and at least a second channel (C2), thermally isolated from one another, cach of which extends along the advancement direction (Y) from the inlet opening (A) to the outlet opening (B); the transport system (T1, T2) comprises at least a first line (T1) and at least a second line (T2), respectively arranged along the first channel (C1) and along the second channel (C2) from the inlet opening (A) to the outlet opening (B).

A kiln for firing ceramic slabs (T) comprising: a heating module (2), a firing module (3), a cooling module (4), consecutively connected to each other along an advancement direction (Y) of the slabs (L), which define a process chamber (C) provided with an inlet opening (A) and an outlet opening (B); a transport system (T1, T2) arranged along the process chamber (C) from the inlet opening to the outlet opening, structured to transport the slabs (L) along the advancement direction (Y) the process chamber (C) comprises at least a first channel (C1) and at least a second channel (C2), thermally isolated from one another, cach of which extends along the advancement direction (Y) from the inlet opening (A) to the outlet opening (B); the transport system (T1, T2) comprises at least a first line (T1) and at least a second line (T2), respectively arranged along the first channel (C1) and along the second channel (C2) from the inlet opening (A) to the outlet opening (B).

In a door structure of a heat treatment furnace performing a heat treatment of a workpiece, there are provided: a first opening member and a second opening member in which workpiece passing ports where the transferred workpiece passes are formed; and a sheet shutter, the sheet shutter is provided with a winding portion and a shutter portion, the shutter portion is disposed between the first opening member and the second opening member, the shutter portion is provided with a first sheet portion which covers the workpiece passing port of the first opening member and a second sheet portion which covers the workpiece passing port of the second opening member at a time that the shutter portion is closed, and it is configured that a gas storage portion is formed between the first opening member and the second opening member at the time that the shutter portion is closed.

In a door structure of a heat treatment furnace performing a heat treatment of a workpiece, there are provided: a first opening member and a second opening member in which workpiece passing ports where the transferred workpiece passes are formed; and a sheet shutter, the sheet shutter is provided with a winding portion and a shutter portion, the shutter portion is disposed between the first opening member and the second opening member, the shutter portion is provided with a first sheet portion which covers the workpiece passing port of the first opening member and a second sheet portion which covers the workpiece passing port of the second opening member at a time that the shutter portion is closed, and it is configured that a gas storage portion is formed between the first opening member and the second opening member at the time that the shutter portion is closed.

An apparatus for calcining a secondary battery cathode material includes: a calcination furnace including an inner space that includes a temperature rising space, a temperature maintaining space, and a cooling space, which sequentially communicate; a plurality of rollers for transferring a sagger, in which a cathode material is accommodated, from the temperature rising space to the cooling space via the temperature maintaining space; a plurality of heaters arranged along the inner space; a plurality of gas feeding parts for feeding gas to the inner space; and a plurality of exhaust parts for exhausting gas from the inner space, wherein the cross-sectional area of the temperature maintaining space is smaller than the cross-sectional area of the temperature rising space and the cross-sectional area of the cooling space.

An apparatus for calcining a secondary battery cathode material includes: a calcination furnace including an inner space that includes a temperature rising space, a temperature maintaining space, and a cooling space, which sequentially communicate; a plurality of rollers for transferring a sagger, in which a cathode material is accommodated, from the temperature rising space to the cooling space via the temperature maintaining space; a plurality of heaters arranged along the inner space; a plurality of gas feeding parts for feeding gas to the inner space; and a plurality of exhaust parts for exhausting gas from the inner space, wherein the cross-sectional area of the temperature maintaining space is smaller than the cross-sectional area of the temperature rising space and the cross-sectional area of the cooling space.

A reflow oven includes a chamber housing including surfaces that are in contact with heated air mixed with contaminants, including flux, and a water-soluble layer selectively applied to the surfaces of the chamber housing. Embodiments of the reflow oven include an acrylic-based layer, such as an acrylic paint. In one embodiment, the acrylic paint includes a water-soluble polymer, a polymer emulsion, and water. The water-soluble polymer includes butyl benzyl phthalate. In some embodiments, the acrylic paint includes 1-10% by weight butyl benzyl phthalate, 30-55% by weight acrylic polymer emulsion, and balance water. In a certain embodiment, the acrylic paint includes 1-5% by weight butyl benzyl phthalate, 35-50% by weight acrylic poly emulsion, and balance water. Methods of treating surfaces of the reflow oven are further disclosed.

A reflow oven includes a chamber housing including surfaces that are in contact with heated air mixed with contaminants, including flux, and a water-soluble layer selectively applied to the surfaces of the chamber housing. Embodiments of the reflow oven include an acrylic-based layer, such as an acrylic paint. In one embodiment, the acrylic paint includes a water-soluble polymer, a polymer emulsion, and water. The water-soluble polymer includes butyl benzyl phthalate. In some embodiments, the acrylic paint includes 1-10% by weight butyl benzyl phthalate, 30-55% by weight acrylic polymer emulsion, and balance water. In a certain embodiment, the acrylic paint includes 1-5% by weight butyl benzyl phthalate, 35-50% by weight acrylic poly emulsion, and balance water. Methods of treating surfaces of the reflow oven are further disclosed.

A heat treatment system may include: a heat treatment furnace including an entrance, an exit, and an internal space through which a plurality of saggars is conveyed from the entrance toward the exit; and a return line located outside the heat treatment furnace and configured to convey the plurality of saggars from the exit to the entrance. The return line may include a first placement unit configured to allow the saggars to be placed thereon. The heat treatment system may include a movement device configured to move the first placement unit; and a first separator configured to separate a first space in which the first placement unit is located from a second space in which the movement device is located.

A heat treatment system may include: a heat treatment furnace including an entrance, an exit, and an internal space through which a plurality of saggars is conveyed from the entrance toward the exit; and a return line located outside the heat treatment furnace and configured to convey the plurality of saggars from the exit to the entrance. The return line may include a first placement unit configured to allow the saggars to be placed thereon. The heat treatment system may include a movement device configured to move the first placement unit; and a first separator configured to separate a first space in which the first placement unit is located from a second space in which the movement device is located.