The aim of this patent is a basically cylindrical vertical body where the displacement of grains occurs through gravity. It is constituted by an antechamber (01) through which the grains enter and are pre-heated when they come in contact with an amount of parallel tubes (02), heated by steam. In the lower part of the chamber (01), there is an entry rotational valve (11) through which the grains pass to the heating chamber (18). Inside the heating chamber (18), there are diverse diametral gutters (14) arranged in opposite positions, with "V" inverted shape walls through which steam is injected into the heating chamber (18) that has a multiple rotational valve of the base (19) in its lower part over the cylinder of the plates (21) heated by steam, where there is an upper heated (22), second (27) and third (28) plates upon which rotational paddles (25) turn that make the grains fall through an opening (26) and a download gutter (32) in the upper one and second plate, and there is a lower rotational valve (31) under the third one.