| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform heat exchange efficiently in a heating duct for heating steam supplied to a heating cooking chamber. <P>SOLUTION: A partitioning plate 37 having a recess in an intermediate part in the direction of steam flow is provided in a first duct 20 to partition into upper and lower two stages, an superheated steam generation heater 23 is provided to be arranged in a circulation part 38 of the lower stage, and at the same time, overheated steam generated by supplying saturated steam is supplied to a bent part 21. In this case, a narrow part 40 of the circulation part 38 which is formed by the recess of the partitioning plate 37 is narrow, raising a flow rate of the supplied steam. As the result, the heat exchange efficiency of the saturated steam and the superheated steam generation heater 23 is raised, Further, an air heat insulating layer is formed in the upper stage of the circulation part 38, and at the same time, by reducing the volume of the narrow part 40, heat radiation by accumulated steam is brought to naught, the interior of the narrow part 40 is made to be in a heat insulated state to raise the interior temperature. As the result, the temperature of a top plate 27 of the heating cooking chamber 13 becomes high to increase radiation heat, so that the efficiency of heating an object to be heated is enhanced, and thereby the shortening of the heating cooking time can be achieved. <P>COPYRIGHT: (C)2013,JPO&INPIT |
