DE1515058A1 - Electrode for high frequency heating - Google Patents

Description

N.Vo Philips Gloeilampenfabrieken, Eindhoven / Holland

"Electrode for high frequency heating"

The invention relates to an electrode for supplying high- frequency energy to dielectric materials for heating purposes, in particular an electrode for applying high frequency energy to uneven surfaces such as concrete, rocks or the like Materialο

To achieve the desired heating effect, concentrated heating energy is supplied to a relatively small volume, so that a considerable increase in temperature can be achieved in a short time and, as a result, cracks due to the exhibit thermal expansion. To get a higher concentration Energy, i. To get a field concentration must at least one of the electrodes used to transfer the energy can bring about a small contact area, and it must a high voltage can be used

The electric field must come from the small electrode expand so that the field intensity is low at a distance from the electrode. This makes it necessary 'an electrode with a relatively large contact area in connection with the field concentration electrode with a small area use.

Another consideration is that too high a stress gradient

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on the heated surface of the material to a superficial one Spark formation and lead to a loss of performance »It is also necessary to establish a low resistance connection between the electrode and the surface in order to localize prevent hot spots or sparks from forming on this electrode ο

The present invention therefore aims to transmit radio frequency energy on an uneven dielectric surface to make a contact with a low Y / resistance in order to heat them up,

According to the invention, the electrode is an intermediate conductor between the dielectric surface and the conductor of a Supply source of high frequency energy effective metallic wool low Added resistance.

The invention is explained in more detail with reference to the drawing

Fig. 1 shows an electrode according to the invention for delivery of high frequency energy between a borehole and a Outside surface of the dielectric material.

Figure 2 shows an electrode for supplying radio frequency energy at separate locations on the surface of a dielectric material to be heated.

Fig. 1 shows a hole 10 in a dielectric material 8, z. B. concrete, the high frequency energy by means of an electrode is fed, which has a conductor 1, which can represent the center conductor of a coaxial cable, with a cup-shaped End part 5, the open end of which is opposite the inner end of the borehole. A metal wool, e.g. B. copper, will between the end part 5 and the end of the borehole together

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presses and makes contact over the entire end face of the borehole because of its resilience.

Another electrode in the form of an annular trough is located of the outer surface or wall of the dielectric material surrounding the central conductor 1 opposite »An insulator 3 with very little dielectric loss fixes and insulates the electrode 2 opposite the conductor 1. The ring-shaped trough electrode 2 is filled with a metal wool, which ensures the contact between them Electrode and the outer surface of the material 8 produces «High-frequency energy is supplied between electrodes 2 and 5," so the dielectric material 8 between these electrodes is heated and the expansion causes cracking or shattering of the material. The electrode 2 can prevent itself or by additional means that shattered material from the Surface of the material flies out.

In FIG. 2, the center electrode 7 can be very similar to 5 and the ring-shaped electrode 6 can be similar to 2. It will be understood that an electrode assembly according to Fig. 1 can be provided with a retractable center electrode to allow for changes in hole depth and also to allow the system to be used on a relatively flat surface. It is not necessary that an electrode such as 2 or 6 be ring-shaped, but this is preferred. It can e.g. For example, two electrodes similar to the center electrodes 4, 5 of the unit of Fig. 1 can be used as the two effective electrodes, two bores being formed to facilitate their use. In this way, a concentrated field can be created in the material between the two boreholes.

Patent claims:

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Claims (4)

Patent claims » 1. Electrode for applying high frequency energy to a surface, the one from a pipe part with a lot attached to it conductive metal wool as an intermediate between this part and the surface consists 2. Electrode according to claim 1, characterized in that the Metal wool fills the concave surface of a conductive electrode body. 3. Electrode according to claim 1 or 2, characterized in that ™ the wool is made of copper. 4. Electrode according to one of the preceding claims, daduroh characterized in that it consists of a conductive center electrode and an annular conductive electrode, including the Surrounding the center electrode and with one made of metallic wool Contact surface is provided. 5o electrode according to claim 4, characterized in that the Position of the center electrode perpendicular to the contact plane of the surrounding Electrode is adjustable 909837/0502