Abstract: A small hot-air circulation furnace performs continuous treatment using hot air at a fixed temperature. Hot air supplied from a heat source is blown out from an axial-flow fan toward a hearth to form a circulating flow passing through an annular heating-target mount on the rotating hearth. The heating-targets are taken out one by one after increasing the temperature of the heating-target on the mount to a predetermined point during one rotation of the hearth. Further, a partition whose outlet-side opening ?2 is narrower than the inlet-side opening ?1 is provided inside the annular partition to supply part of high-temperature gas blown.

Abstract: A hot-air circulation furnace for heating a heating-target to a predetermined temperature by circulating hot air in the furnace, which is capable of performing continuous treatment while the size is small, or forming a heating zone and a soaking zone while using hot air at a fixed temperature. In the interior of the furnace which is divided into an outer peripheral region (6) and an inner region (7) by an annular partition (8) and paths (9) and (10) in the vicinities of a floor and a roof respectively, hot air supplied from a heat source (5) is blown out from an axial-flow fan (11) toward a hearth (2) in the inner region (7) to form a circulating flow passing through an annular heating-target mount (23) on the rotating hearth (2) installed in the outer peripheral region (6). The heating-targets are taken out one by one after increasing the temperature of the heating-target on the mount (23) to be a predetermined point during one rotation of the hearth (2).