Abstract: The present invention pertains to a grate plate utilized in a cooling apparatus. Substantially the entire surface area of the exposed surface, that is, the surface of the grate plate that is not overlapped by a preceding grate plate, is recessed from its outside perimeter. The recessed exposed area is defined by alternating rows of (1) substantially tubular, hollow air distribution conduits that travel substantially the entire length of the recessed exposed area in a direction parallel to the movement of solid material through the cooling apparatus. The tubular air distribution conduits have two side walls and a top surface with which the solid material transported to the cooling apparatus comes into contact, and (2) narrow, open, secondary air distribution channels that also travel substantially the entire length of the recessed exposed area in a direction parallel to the movement of solid material through the cooling apparatus.