DE3011045A1 - ELECTRODE - Google Patents

Description

The invention relates to an electrode in particular for heating glass by passing a directly through it electric current through a glass mass.

In the glass industry, the heating or heating of glass takes place in many cases by direct passage through it an electric current through the glass mass. The electric current is supplied via electrodes instead, which extend through the walls of a so-called feeder into the glass melt. As an electrode material Due to its advantages, molybdenum is preferred

30 turn.

A molybdenum electrode has the advantage that it does not cause any visible contamination in the glass, although a slight consumption or a certain amount during operation

X / 11

Deutsche Bank (Munich) KIo. 51/61070

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Self-consumption of the electrode occurs. However, such a molybdenum electrode has the disadvantage that it requires a substantial and thus costly cooling at the passage through the walls of the feeder, since the free upper surface portions _t of the electrode would be rapidly destroyed otherwise by air oxidation at the very high temperature.

The invention is therefore based on the object of creating an electrode in which the aforementioned Disadvantages and difficulties have been resolved.

This object is achieved according to the invention by an electrode for heating glass mass, for example by directly passing an electric current through the glass, which has a rod-shaped body passed through the wall of a glass feeder or the like and is connected at its outer end part to a power supply element, while its inner end part protrudes into the glass mass, the inner electrode section protruding into the glass mass consisting of molybdenum, while at least the outermost electrode section, which is exposed to very high temperatures in the air, _{consists essentially of molybdenum disilicide (MoSi 9} ).

Advantageous further developments of the invention are characterized in the subclaims.

The invention is described in more detail below on the basis of exemplary embodiments with reference to the drawing.

Show it:

1 shows an axial section of a first embodiment at 35

play of the electrode and

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2 shows a corresponding axial section of a second exemplary embodiment of the electrode.

1 shows an electrode designated by the reference number 10, the innermost section of which, for example, protrudes into a so-called feeder, consists of a rod 11 made of molybdenum. The molybdenum rod is firmly attached to a tube 12, which essentially consists of molybdenum disilicide (MoSi ₂ ). The tube 12 is preferably made of the material commercially available under the trade name "Kanthal-Super". The molybdenum rod 11 and the molybdenum disilicide tube 12 are firmly held together in intimate contact with the aid of a fastening screw or clamping screw 13.

The fastening or clamping screw 13 is in a threaded hole located in the end part of the molybdenum rod 11 screwed in and protrudes outwards a little beyond the outer end of the tube 12, where it is connected to a Nut 14 is provided. Between the nut 14 and the end face of the tube 12 there is one off Belleville or disc springs 15 arranged existing spring pack. The fastening or tensioning screw 13 has an inner section or end section 16 made of molybdenum and one made of steel outer section or end section. The gap 18 between the outside of the Screw 13 and the inside of the molybdenum disilicide tube 12 is at the outer end by means of a suitable

Sealing compound 19 closed.
30th

As shown in Fig. 1, the outer end surface of the molybdenum rod 11 and the inner end surface of the Molybdenum disilicide tube 12, preferably conical or Conical design so that the contact surfaces for

Achieving the lowest possible contact resistance

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be as large as possible.

The embodiment according to FIG. 2 corresponds in principle completely the embodiment of FIG. 1, but has the difference that the outermost section of the molybdenum disilicide tube 12 shown in FIG a steel pipe section 12A is replaced. This is permissible at the extreme end portion insofar as this is here occurring temperatures normally do not reach such high values that a significant risk in relation to a destruction of the electrode end portion is given by air oxidation.

In operation, the electrode is supported by a wall designated by the reference number 20 and only partially shown of the feeder passed through an opening made therein in such a way that a small part of the glass melt can partially flow into the wall like this through the reference number 21 is illustrated in Fig. 1, whereby the glass with only the molybdenum surfaces of the electrode in Touch device.

In addition, various details can be further developed within the scope of the invention. That's how it is Compensation of the different coefficients of thermal expansion of molybdenum and molybdenum disilicide possible, the screw sectioni 7 and the ear sectioni 2A instead of To produce steel from other materials, one

have even higher coefficients of thermal expansion. 30th

It thus becomes an electrode for heating a glass mass by passing an electrical one directly through it Proposed current through the glass mass, which one through the wall of a feeder or the like-

has guided rod-shaped body and on her

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outermost end part is connected to a power supply element, while the innermost end part protrudes into the glass mass. The innermost electrode section protruding into the glass mass consists of molybdenum, while the outermost electrode section, which is exposed to very high temperatures in the air, consists of molybdenum disilicide (MoSi _? ) And is preferably designed in the form of a tube.

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Claims (1)

Claims [ 1 «Electrode for heating a glass mass, for example by directing an electric current through the glass, characterized in that a rod-shaped electrode body (10) is passed through the wall (20) of a glass feeder or the like and at its outer end part with a power supply element is connected, while its inner end part protrudes into the glass mass, and that the inner electrode section (11) protruding into the glass mass consists of molybdenum, while at least the outermost electrode section (12 or 12A), which is exposed to very high temperatures in the air, essentially made of molybdenum disilicide (MoSi ₂ ) 25 exists. 2. Electrode according to claim 1, characterized in that the outermost electrode section consists of a tube (12), that is in intimate end face contact with the innermost electrode section formed in the form of a molybdenum rod (11) by a fastening or tensioning screw (13) which passes through the pipe and is screwed into 'the molybdenum rod and at its end protruding from the tube with a spring pack (15) and a fastening or clamping nut (14) is. 030047/0841 2 DE 0315 1 3rd electrode according to claim 1 or 2, characterized in that that the tube has one adjacent to the molybdenum rod Has pipe section (1 2) made of molybdenum disilicide and a pipe end section (12A) made of steel. 4. Electrode according to one of claims 1 to 3, characterized in that the fastening or tensioning screw (13) has an inner innermost section (16) made of molybdenum and an outermost Ab-10 has section (17) made of steel. 03004? / 0β4