MICROWAVE THAWING HEATING DEVICE AND THAWING HEATING METHOD FOR 'SUSHI' AND SURFACE WAVE FORMING PLATE FOR THAWING HEATING

摘要

PURPOSE: To excellently thaw heat a 'sushi' without warming the material of the 'sushi' by making heating efficiency different in a vertical direction. ;CONSTITUTION: An alumina surface wave forming plate 14 is arranged at an interval of about 15 mm to a metallic turntable 12 arranged in a thawing heating chamber 10. Here, the portion between the turntable 12 and the ceiling of the thawing heating chamber 10 is made about nλ/2 (λ: the wave length of a microwave, n: an integer) so that a standing wave can be formed, and the surface wave forming plate 14 is arranged in the vicinity of a position where the electric field strength of the standing wave is high. The surface wave forming plate 14 is preferably dielectric material having a dielectric loss angle of 0.01 or smaller and a dielectric constant of 4 or larger. This forms electric field strength distribution, weaker with an upper side, on the surface wave forming plate 14. By a microwave having this ununiformed electric field strength, the thawing heating treatment of a refrigerated 'sushi' 3, placed on the surface wave forming plate 14, is performed, resulting in obtaining a 'shari (rice)' in appropriate temperature and cold material. When the surface wave forming plate 14 is to be enlarged, the thickness of the middle part is made thicker than that of an outer peripheral part.;COPYRIGHT: (C)1996,JPO