| 摘要 |
1,133,011. Dielectric heating electrodes. TESLA NARODNI PODNIK. 2 Nov., 1965 [10 Nov., 1964], No. 46304/65. Heading H5H. [Also in Division B5] The exposed conductive surfaces of at least two electrodes 30 projecting into a dielectric heating chamber of an extrusion press are specially profiled to produce a uniform heating field. Arrangements described (Figs. 1 to 10, not shown) comprise up to eight electrodes, those with more than two electrodes being connected to a multi-phase supply. Pairs of electrodes may be of different sizes, and a conductive or insulating mandrel or mandrels may be arranged along or around the longitudinal axis of the chamber. Suitable electrode profiles are defined with reference to the instantaneous equipotential surfaces produced by two hypothetical electrodes located on, and having a contour corresponding to, the periphery of the heating chamber. The transverse section (Fig. 16, not shown) of a suitable profile lies between surfaces representing 10% and 40% of the maximum instantaneous value of the applied potential, and the longitudinal section (Fig. 17, not shown) lies between surfaces representing 5% and 40% of that value. The heating chamber may be tapered instead of cylindrical, and the longitudinal axes of the electrodes may not be parallel to the longitudinal axis of the chamber, e.g. they may follow helical paths.
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