US 4,287,380 AGranted

Electrode assembly for molten glass forehearth

AssigneeEmhart Industries, Inc.

InventorsRichard E. Fairbanks, James F. Stevenson, John F. Blumenfeld

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Abstract

A molybdenum electrode is mounted in a stepped aperture in the sidewall of the forehearth such that the inner end portion of the electrode is immersed in the molten glass where the molybdenum is effectively isolated from oxidizing agents. The outer end portion of the electrode is shielded in a high temperature alloy steel sleeve, which sleeve is spaced from the electrode to provide an annular space therebetween. A ceramic fiberous material is provided between the inner end of the sleeve and the electrode, and a high temperature alloy steel plug is threadably secured to the outer ends of both the sleeve and the electrode to seal the outer end of this annular space, and to serve as an electrical terminal for the electrode. The molten glass solidifies inside the sleeve's inner end to seal the inner end of the sleeve. The assembly is clamped to the furnace framework by an insulated bracket adjacent the outer end of the sleeve, which bracket is designed to thrust the assembly inwardly so that an annular flange on the sleeve abuts the sidewall of the refractory channel, which sidewall defines the step in the aperture of the furnace forehearth sidewall itself.

Claims12

Dependent claims

An electrode assembly adapted to be mounted to the framework of a furnace forehearth, and to extend through a stepped aperture defined in the furnace sidewall below the normal level of the molten glass contained therein, said electrode assembly comprising

a tubular sleeve of inert high temperature nickel alloy steel material and having an outside diameter which is less than the diameter of the smaller portion of the stepped aperture in the furnace sidewall,
said sleeve having radially projecting flange means intermediate its ends which flange means is adapted to abut the stepped portion of the aperture in the furnace sidewall, said flange means including a gasket for abutting the shoulder of the stepped aperture in the furnace sidewall,
means for mounting said sleeve to the furnace framework so that the sleeve is clamped axially inwardly of the furnace sidewall aperture to thrust said flange means against the shoulder of the stepped aperture in the furnace sidewall,
an elongated electrode of readily oxidizable material positioned inside said sleeve and having an inner end projecting into the molten glass, said electrode having a diameter significantly less than the inside diameter of said sleeve,
a plug for connecting the outer end of said electrode to the outer end of said sleeve so that the electrode is oriented in spaced coaxial relationship inside said sleeve to define an annular space therebetween, and
non-metallic spacer means between the inner end of said sleeve and said electrode to support the electrode coaxially of said sleeve and to block the flow of molten glass into said annular space by reason of the glass hardening between said electrode said sleeve and said spacer means.

3 more elements

Dependencies are inferred from the claim text.