EXTERNAL-HEATING TYPE ROTARY KILN

PROBLEM TO BE SOLVED: To strictly control the heating temperature of a treatment object and the retention time of the temperature, and at the same time, to resolve the inconvenience to be caused by lengthening of a reactor core tube by arrang ing a plurality of independent heating ovens which are surrounded by peripheral and end-part walls along the reactor core tube, and at the same time by arrang ing support means at a plurality of places, where the part between the heating ovens is included. SOLUTION: At the outside of a reactor core tube 20, two independent heating ovens 11 and 12 are arranged, an end-part wall is provided in one piece at both the sides of a periphery wall for surrounding the reactor core tube 20, and independent space is formed at the inside. In each of heating ovens 11 and 12, burners 11a and 12a that can be individually operated are provided for individually adjusting the heating temperature. As a means for rotatably supporting the reactor core tube 20, rollers 31 and 33 are arranged near the ends of the reactor core tube 20, and at the same time a roller 32 is provided between the heating ovens 11 and 12. Also, the outer periphery of the reactor core tube 20 is integrated with annular bodies 21, 22, and 23 according to a roller position for smoothly supporting by the rollers 31, 32, and 33.