Improvements in and relating to ultra-high frequency electromagnetic radiation heating apparatus

摘要

666,074. Dielectric heating. BRITISH THOMSON-HOUSTON CO., Ltd. Feb. 28, 1949. [March 4, 1948] No. 5389/49. Class 39(iii). Semi - conducting materials, e.g. foods, cellulose products and organic substances, are heated in electric and electromagnetic fields of high frequency, e.g. 1,000 megacycles in a resonant cavity 16 of circular cross-section, the material being supported on a stand 32 rotatable about an axis 33 eccentric to the cavity to obtain equal heating throughout. A cylindrical metal cooking vessel 16 is removably supported in an annular opening 15 in a metal casing 12 and has a removable metal lid 23. Through an opening 30 in the cylindrical wall of the vessel 16 project two antennae 31 of a H.F. generator 28 supported by a metal shield 29 in the casing 12. The vessel 16 is closed by a metal lid 23 bearing on a braided metal gasket 27, and the material to be heated e.g., a cake 37 in a glass dish on the stand is rotated once a minute by a synchronous motor 36. The two vertically-spaced U- shaped antennae 31 projecting towards the axis of the stand set up standing waves in the receptacle with a maximum energy line in the centre. The shaft 33 is of lava and is to one side of the centre of the receptacle. Specification 629,446 is referred to.