Large scale mixer / reactor

Over one section of the reactor length (142), the rotors (18, 20) convey the reaction material axially. Over a further section of the reactor length (144) the reaction material is conveyed in the opposite direction. These sections are divided by a plane of separation (140) at right angles to the rotor shaft. The rotor construction in the two sections (142, 144) is symmetrical about the plane of separation. The plane of separation coincides with one of the planes of rotor segments. Each of the segment planes includes a segment disc carrying a parallel kneading bar on one side, connected exclusively with the one segment disc. The other side carries a kneading bar connecting both axially-adjacent segment discs. The casing (14) has two end walls, with a corresponding arrangement of adjacent kneading bars and segment discs. The arrangement of kneading bars is parallel to the axial direction. They are alternatively inclined with respect to the axial direction, and provide both axial dispersion and axial conveying of the reaction materials. The casing includes connections for: exhaust vapors or gases (108), materials inlet (104) and reacted materials outlet (106). Further mechanical details are claimed. Two rotors are contained in a casing. The segment discs are arranged on spiral lines. The rotors are operated in counter rotation; they are periodically reversed. An independent claim is included for the method of operation.