| 摘要 |
1,181,208. Microwave heating. RCA CORPORATION. 10 April, 1968 [10 April, 1967], No. 17243/68. Heading H5H. [Also in Division F4] Lossy dielectric material 18 is heated in a waveguide 10 having a non-linear taper along its length, the microwave energy being propagated in the TE 01 mode only in the direction of the taper so that the maximum energy passes through the material. The form of the taper is chosen to provide uniform heating along the length, and is such that the ratio between the energy propagated and the admittance of the waveguide is constant along the direction of the taper. The invention can be applied to the freeze drying of frozen food by sublimation, apertures (28, Fig. 4) being provided for vapour, or to drying or curing of textiles, paper, plywoods, adhesives, plastics. The material can travel lengthwise through the waveguide in either direction on a continuous conveyer 16, or it may be stationary in the waveguide. A single microwave generator may supply energy to two end-to-end waveguides (Fig. 4). The material may be passed transversely through a plurality of side-by-side waveguides, each fed from a separate microwave input (Fig. 5).
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