Vertical oven for mainly flat parts

A method of drying mainly flat painted panels comprising:

• providing a vertical oven comprising:
• at least two vertical transit chambers (21, 22);
• a plurality of trays (41, 42, 43, 44, 45, 46, . . . ) configured to support the painted objects, the plurality of trays being arranged in a stack (31, 32;
• 81, 82, 83, 84) of superimposed trays within each of the at least two transit chambers (21, 22);
• and
• motorized tray conveyors that displace the trays along a path comprising at least an ascending portion inside a first transit chamber of the at least two transit chambers, a lateral shifting portion from the first transit chamber to a second transit chamber of the at least two transit chambers, and a descending portion inside the second transit chamber,
• wherein one or both of an input or output port are provided at a bottom of the at least two transit chambers, at which there is provided alternatively or in combination a loading unit, an unloading unit of the dried painted objects from the trays, and a conveyor shifting the trays from a lower end of the second transit chamber to a lower end of the first transit chamber for recirculating the trays along the path inside the at least two transit chambers,
• wherein the trays (41, 42, 43, 44, 45, 46, . . . ) have a predefined distance from each other in the stacks inside the at least two chambers (21, 22),
• wherein the vertical oven includes a parking chamber (23);
• wherein the parking chamber (23) is configured to temporarily park one or more of the trays (42, 44, 43) in a stack of parked superimposed trays;
• wherein transferring devices adapted to withdraw trays from the stack of the first or the second transit chamber and feed the trays to the parking chamber or for re-insertion of the trays in the stack of the first or the second transit chamber,
• wherein a control unit controls the transferring devices to withdraw every second tray in the stack of the first or the second transit chamber and parks the withdrawn tray in the parking chamber (23), thus doubling the predefined distance between the trays in the stack of the first or the second transit chamber (31, 32;
• 81, 82, 83, 84),
• wherein even trays (42, 44, 46, . . . ) in the stack follow a different path from a path of odd trays (41, 43, 45, . . . ) in the stack, and
• wherein the even trays (42, 44, 46, . . . ) are parked in a pre-set area (22;
• 75, 76) for any desired time, and
• wherein the odd trays are driven along a predefined path and with an increased distance between the odd trays (41, 43, 45, . . . ), the increased distance corresponding to a double distance of the stack before transferring the even trays into the parking chamber adjacent to the first and the second transit chamber.