Abstract

Method and apparatus for drying granulate material in a hopper by controlling the amount of gas which flows through the hopper to heat and to dry the granulate. The control allows to use a minimum amount of gas for heating the granulate to the drying temperature and to dry it with an optimal low energy consumption. This effect is reached by controlling the amount of gas flowing through the drying hopper as a function of the temperature difference between the temperature of the heating gas leaving the drying hopper and the granulate to be heated.