Rotary heat treatment furnace

A rotary heat treatment furnace comprising:

• a furnace body having an inside that is partitioned into a first zone and a second zone;
• a housing rotary body rotatably supported and disposed so as to straddle the first zone and the second zone, the housing rotary body including:
• a plurality of side walls extending radially;
• a plurality of housing chambers partitioned by the side walls, the housing chambers each having a substantially same size, the housing chambers being disposed circumferentially in multiple stages, each of the multiple stages including multiple housing chambers;
• and a space disposed in the central portion of the housing rotary body so that the housing rotary body is provided with a donut shape in plan view;
• a rotary driving device for rotating the housing rotary body;
• a heating device for heating the air inside the furnace body;
• a fan for feeding hot air prepared by the air heated by the heating device to the housing rotary body;
• a first partition wall and a second partition wall, the first partition wall extending from the fan towards the housing rotary body while the second partition wall extending from a wall surface of the furnace body towards the housing rotary body, the first partition wall and the second partition wall together partitioning the inside of the furnace body into the first zone and the second zone;
• a first flow passage communicating a blowout port of the fan with outer circumference sides of the housing chambers positioned in the first zone;
• and a second flow passage communicating outer circumference sides of the housing chambers positioned in the second zone with a suction port of the fan, wherein:
• when the first partition wall is in such a state that an end portion thereof at a side of the housing rotary body side comes closer to one of the side walls, the second partition wall is in such a state that an end portion thereof at a side of the housing rotary body comes closer to another one of the side walls;
• the hot air provided by the fan and passed through the first flow passage is fed substantially horizontally to the outer circumference sides of the housing chambers positioned in the first zone and further to the space side;
• and the hot air is then fed substantially horizontally from the space side to the outer circumference sides of the housing chambers positioned in the second zone, and is returned to the fan through the second flow passage.