Owens-corning Fiberglas Corporation

Charles S Dunn

Stephen Seng

Mark A Propster

Charles M Hohman

Michael D Hickman

Eugene C Varrasso

A channel made from refractory elements is fabricated without gaps or expansion joints between the refractory elements by supporting the channel upon a movable carriage to accommodate the lengthwise expansion of the channel as the temperature of the channel is increased from room temperature to its operating temperature.

Apparatus for supplying molten glass and method of fabricating same

A method and apparatus for heating the portion of an electrode protruding from a glass melting furnace is disclosed. One embodiment of the invention describes an electrical resistance heated device. A second embodiment discloses a gas and air fired infrared heater device. Both devices allow the electrode to be heated to an elevated temperature without oxidation of the electrode thereby allowing the electrode to be forced into the furnace without damage to the furnace or the electrode.

Electrode heater

An apparatus for changing bushings in a glass melting furnace is disclosed. A support attached to the furnace holds the bushings beneath an opening in the forehearth. A replacement bushing is placed in the framework, translated next to the operating bushing, brought to operating thermal condition and then both bushings are translated until the replacement bushing is beneath the opening in forehearth. This eliminates the need to freeze the molten glass within the bushing.

Method and apparatus for changing bushings

A melting furnace is disclosed which heats by joule effect to supply molten material of uniform temperature at the floor of the melter. During formation of molten material, an essentially isothermal condition across a given horizontal plane of the body of molten material is established. Spaced apart opposed electrodes and controlled current flow establish these uniform temperatures and allow molten material to be formed directly from the melter without further processing.

Melting furnaces

This invention proposes a method of controlling the melting rate of a glass furnace to obtain substantially constant molten glass throughput. The furnace contains a pool of molten glass and a relatively thin layer of unmelted glass batch on the surface of the pool. The furnace contents are weighed, and the batch feed is controlled by the measured weight. In essence, the melting rate is determined by the thickness of the lighter, thermally insulated batch layer, since a thinner batch layer results in more heat loss through the batch and less batch melted by the cooler molten glass. Thus, a decrease in weight indicates more molten glass withdrawal and a lower melting rate, and batch is added to increase the molten glass temperature and to melt more glass batch. In the preferred embodiment, the furnace is electrically heated at a constant rate, and only the rate of batch feed is controlled to maintain substantially constant glass throughput.

Method and apparatus for melting glass

An apparatus for adjustably supporting a vertical electrode for an arc-type furnace. The apparatus includes an upper stationary electrode clamping structure and a lower adjustable electrode clamping structure suspended from the upper structure by adjustment screws. The two clamping structures are mounted on a carriage movable linearly into and out of registry with the furnace to accommodate maintenance and repair. Each clamping structure comprises an arcuate electrical contact and wedge-type slips engaging the periphery of the electrode in opposition to the electrical contact, the slips being spring-biased into electrode engagement and cam actuated from electrode engagement. The cams are actuated by a common shaft extending between the two clamping structures, so that the electrode is released from one clamping structure when engaged by the other clamping structure.

Electrode support mechanism and method

An arc glass-melting furnace comprising: a chamber adapted for holding a body of molten glass, such chamber including means for supplying batch material thereto and means for withdrawing molten glass therefrom; an arc electrode positioned in the chamber above the upper surface of the body of molten glass; a plurality of electrodes positioned in the bottom of the chamber; and power supply means having a first terminal connected to the arc electrode and a second terminal connected to the plurality of bottom electrodes.

Arc circuit electrodes for arc glass-melting furnace

A glass heating method and apparatus, such as a glass melting furnace or a forehearth, utilizing a refractory lining and electrically energized heating electrodes. The refractory lining is an erosion resistant material, preferably a chromic oxide refractory, having an electrical resistivity which is less than the resistivity of the molten glass, preferably an E glass, which is being heated. To avoid short-circuiting through the low resistance refractory, the refractory interposed between electrodes of opposite polarity is cooled to a temperature less than the temperature of the molten glass and at which the resistivity of the refractory is materially increased. Where the electrodes of opposite polarity are carried by opposing side walls, the end and/or side walls of the apparatus are cooled. Where the electrodes are all carried by a single wall, that wall is cooled.

Electric glass melting furnace

Controlling the level of molten material in a melting furnace is disclosed. The level of molten material is sensed downstream of the furnace and batch materials are choke fed to keep the total batch crust plus molten glass depth constant. This provides for simpler molten glass level control as melter power can be directly controlled in response to glass level.

Method for controlling the level of molten material in a furnace

A method of recovering heat from furnace flue gas which comprises passing the hot gases into contact with high specific heat media and the media into contact successively, with combustion gases and glass batch.

Recuperation of heat absorbent media to preheat combustion gases and

The feeding of batch material to a melting furnace is disclosed. The batch materials are choke fed to keep the total batch crust plus molten glass depth constant. The batch level keeps the arc electrodes submerged and helps promote arc stability and melting efficiency.

Method and apparatus for feeding raw material to a furnace

A method and apparatus for determining the level of slag containing iron or iron compounds in the bottom of a glass melting furnace is disclosed. Electrically conductive electrodes or probes are placed in a predetermined position in the furnace. When the iron containing slag touches the electrodes or probes, the resistance between the electrodes or probes decreases or the current flowing between them increases activating a signal or alarm to warn the operator of the level of the slag in the furnace.

Method and apparatus for determining the level of slag containing iron

An electrode support mechanism and method for use in electric arc melting or smelting furnaces wherein a pair of horizontal, superimposed arms are each provided with clamping devices at their outer end for supporting and supplying electric power to a vertically disposed electrode depending into an arc furnace. The arms are each supported on a vertical support post; the upper arm is fixed to the post and the lower arm which normally carries the electrode is movable relative to the post to adjust the electrode to maintain a constant arc at the furnace. The movable arm is moved vertically by a jack screw carried by the upper arm and depending into contact with the lower arm. The clamping devices at the ends of the arms are spring-biased toward contact with the electrode, and a linking mechanism is provided to alternately release the arm clamping mechanisms from the electrode under the control of an actuating system utilizing fluid pressure actuated cylinders. The electrode is clamped to the lower clamping arm when the lower clamping arm is operating within its normal range of adjustment, but the electrode is released from the lower arm and clamped to the upper clamping arm whenever it is necessary to move the lower arm independently of the electrode to reposition the lower clamping arm within its normal range of adjustment. When the lower arm is so repositioned, the electrode is reclamped by the lower arm and released by the upper clamping arm.

An apparatus for replenishing electrodes in an arc furnace or the like. The apparatus threadedly attaches a replenishment electrode section to a previously installed, presently working electrode section without interrupting the operation of the furnace. The electrode sections are provided with mating terminal threaded portions which are engaged by simultaneousy lowering and rotating the replenishment electrode section. By lowering the replenishment electrode at a faster rate than the lead of the electrode threads and accommodating relative vertical movement of the electrodes, it is not necessary to precisely match the lowering speed of the replenishment electrode with the threads of the electrode. A novel screw-driven, electrically insulated, telescopic drive train is employed for this purpose. The replenishment electrode is carried by a plurality of peripherally spaced wedges actuated independently of the drive train to retain and release the electrode. The telescopic drive train may incorporate either a universal joint in combination with a telescopic connection or reversely wound helical springs which both rotate the electrode and compress to permit the replenishment electrode section to move relatively upwardly during threading.

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Pataskala, OH, United States of America

Charles S Dunn