A method of controlling the efficiency of a bulk material cooler

The invention relates to a method for controlling the speed of a bulk material cooler (1) having bulk material (5) transported by non-simultaneous forward and backward movements of planks (p) from an entry end (E) to a discharge (A), and in which cooling air ( 8) through cooling air openings (in the planks P) from below through the lying on the planks bulk material (5) flows through and thereby absorbs heat, wherein the (by the cooling air 8) depends amount of heat absorbed a) of the speed of movement of the bulk material (5 ) (by the bulk material cooler 1), and b) the amount of air that flows (through the bulk material (5) during the movement of the bulk material (5) through the bulk material cooler 1). According to the invention it is provided that a control device (11) controls the speed of forward and backward movements of the planks (P) as a function of a measured bulk density measurement, wherein the control loop, a detection of an increased bulk density is accompanied by a slowing of the speed and detection of a reduced bulk density accompanied by an increase in speed. Thus, the control is stabilized relative to other control methods based on the measurement of other parameters,