Abstract: Trays are provided with identical vertical spacers which enable the trays to be stacked on top of each other in a centered way, with a suitable or appropriate spacing between them, and enable the various adjacent stacks of trays to be raised and lowered in steps, by an elevating and lowering system which acts only on the bottom tray of each stack. The sides of the stacks of trays of the kiln are thus free and can be engaged by conveyors for the translation of the trays between the stacks, both in a normal operating cycle and in a short operating cycle. However, the lower translation conveyors, which transfer the trays from the stack with an unloading station to that with a loading station, are positioned in the conventional way, i.e., under the stacks of trays and transversely with respect to the trays.

Abstract: The trays (V) are provided with identical vertical spacers (4) which enable the trays to be stacked on top of each other in a centred way, with a suitable spacing betweem them, and enable the various adjacent stacks of trays to be raised and lowered in steps, by means (BM) which act only on the bottom tray of each stack. The sides of the stacks of trays of the kiln are thus free and can be engaged by conveyors (37-37′, 77-77′, 57-57′) of the means provided for the translation of the trays between the stacks, both in the normal operating cycle and in the short operating cycle. However, the lower translation conveyors (24-24′) which transfer the trays from the stack with the unloading station (K2) to that with the loading station (K1) are positioned in the usual way under the stacks of trays and transversely with respect to the trays.