Abstract: The invention relates to a roller belt drier. The drying of panel-shaped products often requires the drier to have considerable construction lengths in order to achieve a high capacity. Long roller belt dryers, which are usually equipped with chain drives and a motor for each chain, present the problem that very strong chains are required to transmit the necessary driving forces. When the drier reaches a certain length, it is no longer possible to provide chains that are able to accommodate these forces. According to known solutions, a chain is divided and the drives are located in the centre of the drier. This causes problem s in terms of sealing the drier, as well as extra expense for the driving and tension station. The aim of the invention is to create a drier which has a driving and tension system that is structurally simple and economical even for considerable construction lengths. A chain is equipped with two drives (15, 23), the second drive (23) being integrated in a tension device (24).

Abstract: A drying apparatus has a housing, a conveyor for displacing a flat workpiece horizontally in a travel direction through the housing on a level, and a horizontal array of horizontally elongated upper nozzle boxes lying generally in a plane above the level. Each box is formed with a plurality of downwardly directed nozzle holes and heated air is fed to the boxes so it is projected from the holes against the workpiece for drying same. Respective upper shield plates each formed with a plurality of apertures are slidable on the respective boxes between a position with the apertures aligned with at least some of the respective holes and a position with the apertures out of line with the respective holes. At least one pivotal rod extending along a rod axis in the direction has radially projecting arms each engaged with a respective one of the respective shield plates. The rod can be pivoted about the rod axis to shift all the shield plates between their positions.

Abstract: A drier for broad articles such as plasterboard has a conveyor in entraining the plasterboard along a drying path in a transport plane and the nozzle boxes for contacting the plasterboard with the drying air have their orifice surfaces inclined to the plasterboard to achieve uniformity of drying in terms of residual moisture content.

Abstract: In order to dry boards, the boards are guided on racks through a drier and brought into contact with drying air in two stages. In a stage A with a higher drying power, the drying air is supplied at a higher temperature and with an at least average humidity, and in the other stage B, it is supplied at an average temperature and with a low humidity. The waste heat of the outgoing air from stage A is used for preheating the drying air. This process should reduce the consumption of primary energy. For that purpose, a process is known that consists of also using the outgoing air condensation heat. This has the inconvenience, however, of requiring substantially more secondary energy, as important air mass flows are required to transfer heat because of the low condensation temperature. Primary energy should be reduced by using condensation heat without substantially increasing secondary energy requirements.

Abstract: In order to dry boards, the boards are guided on racks through a drier and brought into contact with drying air in two stages. In a stage A with a higher drying power, the drying air is supplied at a higher temperature and with an at least average humidity, and in the other stage B, it is supplied at an average temperature and with a low humidity. The waste heat of the outgoing air from stage A is used for preheating the drying air. This process should reduce the consumption of primary energy. For that purpose, a process is known that consists of also using the outgoing air condensation heat. This has the inconvenience, however, of requiring substantially more secondary energy, as important air mass flows are required to transfer heat because of the low condensation temperature. Primary energy should be reduced by using condensation heat without substantially increasing secondary energy requirements.