A dryer for drying boards to be conveyed through the dryer in a plurality of sections extending one behind the other in the longitudinal direction and each having a plurality of levels using a heating medium at a temperature below 130 C., characterized in that the boards are heated during the drying process in a first zone in the longitudinal direction and in the conveying direction of the boards with warm air flowing between the levels, the boards can be heated to a temperature below 130 C. in a first zone in the longitudinal direction and in the conveying direction of the boards by warm air generated by a first heater in one or a first plurality of zones, and in that the air can be led out of the dryer counter to the conveying direction through at least one first heat exchanger after absorbing moisture from the boards.

A method for drying panels in a drying device includes first and second stages. Each stage has levels, and each panel is placed on surfaces formed at different levels and guided through the drying device in each level. In the first stage, the panels are brought into contact with drying air with a high temperature and are dried, and in the second stage, the panels are dried using drying air with a lower temperature. The support surface in the levels of the first stage for placing the panels is smaller than the support surface in the second stage, and the panels are guided in the second stage at a second speed which is lower than the first speed in the first stage, wherein the product of the first support surface and the first speed is equal to the product of the second support surface and the second speed.

A conversion kit (202), which is suitable for the conversion of a treatment plant, in particular an existing treatment plant, for treating workpieces, in particular drying vehicle bodies, wherein the conversion kit (202) comprises the following: one or more auxiliary heating apparatuses (206, 208, 210), which are suitable for heating a clean gas guided in a clean gas guide system (126) and/or fresh air guided in a fresh air guide system (122); and a) a regenerative thermal oxidation apparatus (204) as replacement for an in particular fossil fuel-heated, thermal post-combustion apparatus (142); or b) a regenerative thermal oxidation apparatus (204) as replacement for a fresh air heat exchanger (144) and a converted, in particular fossil fuel-heated, thermal post-combustion apparatus (142) for use as fresh air heat exchanger (150); or c) a regenerative thermal oxidation apparatus (204) as replacement for an in particular fossil fuel-heated, thermal post-combustion apparatus (142) and electrically heated recirculated air modules (214) as replacement for recirculated air modules (110) having heat exchangers or converted recirculated air modules (214) having electrical heating registers instead of heat exchangers.

An air supply-and-exhaust device includes: a heating device to heat a sheet to which liquid is applied; an air supplier including an air supply path to supply air into the heating device via air supply ports disposed in the heating device; an air exhauster to exhaust air in the heating device; and a heat exchanger to recover heat of air exhausted by the air exhauster and apply the heat recovered by the heat exchanger to air supplied by the air supplier to heat the air. Heated air heated by the heat exchanger is supplied into the heating device via at least one air supply port of the air supply ports. Non-heated air not heated by the heat exchanger is supplied into the heating device via at least one other air supply port of the air supply ports than the at least one air supply port.

A material drying and cooling integrated machine, comprising a heating module, a drying module, a dust removal filter module, a temperature-lowering and dehumidifying module, and a cooling module. Dry hot air generated in the heating module can enter the drying module to dry materials; the temperature-lowering and dehumidifying module can conduct temperature lowering and dehumidification on air entering the interior thereof so as to form dry cold air, and the dry cold air can enter the cooling module to cool materials in the cooling module; the dry hot air enters the drying module to dry the materials in the drying module, then damp hot air is formed, and part of the damp hot air can be heated by the heating module again; the other part of the damp hot air can sequentially pass through the dust removal filter module and the temperature-lowering and dehumidifying module, and dry cold air can be formed.