Method and apparatus for treating a layer of bulk material

A method for cooling a layer of hot bulk material that emerges from a firing furnace, comprising:

• providing a grate carrying the bulk material positioned at a point downstream from a bulk material exit of the firing furnace which comprises a plurality of planks which are elongate in a conveying direction for the bulk material,
• passing a stream of gas at a temperature lower than the temperature of the hot bulk material through the layer of hot bulk material,
• driving the plurality of planks in advancing strokes and return strokes in the conveying direction in such a manner that at least two adjacent planks are moved forward simultaneously and are moved back non-simultaneously so as to convey the bulk material in the conveying direction, and
• measuring conveying parameters separately for the bulk material located on individual planks or a group of adjacent planks and determining the conveying speed of the individual plank or group of planks at least in part as a function of these measurements.