Patent ID: 7997003

Claim:
A multi-level dryer adapted to dry plate-shaped products, said dryer having at least one dryer zone, each of which comprises: a housing that includes a housing ceiling at a top of said housing, with an air collecting space formed within said housing under said housing ceiling; plural transport devices that are arranged at plural levels above one another in said housing, and that are adapted to transport the plate-shaped products horizontally through said housing at product locations respectively at said plural levels; plural air distribution boxes that are arranged above one another and respectively between said product locations, and that have air distribution openings directed at the product locations; plural blowers that are arranged above one another in said housing; at least one air circulation path extending in a circuit from a pressure side of said blowers via said air distribution boxes along said product locations and back to suction sides of said blowers; at least one heater interposed in said air circulation path upstream from said suction sides of said blowers and downstream from said product locations; and a vertically extending air channel that extends vertically in said housing adjacent to said blowers, wherein said air channel has an inlet opening in said air collecting space under said housing ceiling, said air channel has plural outlet openings adjacent to said blowers and communicating with said suction sides of said blowers, and said air channel establishes a secondary air path from said air collecting space to said suction sides of said blowers.