| 摘要 |
<p>A partitioning plate (37) having a concave part at the middle part in the direction of vapor flow is disposed within a first duct part (20) to partition the first duct part (20) into an upper section and a lower section, and a superheated steam producing heater (23) is disposed within a circulating part (38) in the lower section. Superheated vapor generated by supplying saturated water vapor is supplied to a bent part (21). In such a case, the narrow part (40) of the circulating part (38) formed by means of the concave part of the partitioning plate (37) is narrow and the flow rate of the supplied vapor increases. As a result, the heat exchange efficiency between the saturated water vapor and the superheated steam producing heater (23) increases. Moreover, an air thermal insulating layer is formed on the upper section of the circulating part (38) and the volume of the narrow part (40) is reduced to eliminate heat being released by means of remaining vapor, thereby raising the interior temperature while the interior of the narrow part (40) is thermally insulated. As a result, the radiant heat increases as the temperature of the top plate (27) of a heating cooking chamber (13) increases, thereby being able to increase the heating efficiency of an object to be heated and to shorten the heating cooking time.</p> |
