Abstract: A hollow tubular body for molten glass by which local-overheating in the electrode for conduction heating is prevented. A hollow tubular body for molten glass by which local-overheating in the electrode for conduction heating is prevented. A hollow tubular body having a platinum or platinum alloy hollow tube, used for conduction heating is characterized in that a ring electrode is joined to the outer circumference of the hollow tube, at least one lead-out electrode is joined to an outer edge of the ring electrode, and the ring electrode comprises a core portion of electrode of platinum or platinum alloy and a thick portion of platinum or platinum alloy or of a metallic material other than platinum or platinum alloy, provided at an outer side of the core portion of electrode.

Abstract: There is provided a method for electrically energizing and heating a platinum or platinum-alloy composite tube structure having a structure including a first main tube, a second main tube, and a branch tube connecting the first main tube and the second main tube, which prevents a local part of the branch tube from being electrically energized and heated in an excessive or insufficient manner.

Abstract: A hollow tubular body for molten glass in which local-overheating is reduced at the time of conduction heating. The hollow tubular body has a platinum or platinum alloy hollow tube, used for conduction heating, wherein a platinum or platinum alloy ring electrode is joined to the outer circumference of the hollow tube, a lead-out electrode is joined to an outer edge of the ring electrode, and a thick portion is provided in at least the joint portion closest to the lead-out electrode, of the ring electrode and in the vicinity thereof.

Abstract: A hollow tubular body for molten glass in which local-overheating is reduced at the time of conduction heating. The hollow tubular body has a platinum or platinum alloy hollow tube, used for conduction heating, wherein a platinum or platinum alloy ring electrode is joined to the outer circumference of the hollow tube, a lead-out electrode is joined to an outer edge of the ring electrode, and a thick portion is provided in at least the joint portion closest to the lead-out electrode, of the ring electrode and in the vicinity thereof.

Abstract: A hollow tubular body for molten glass by which local-overheating in the electrode for conduction heating is prevented. A hollow tubular body having a platinum or platinum alloy hollow tube, used for conduction heating is characterized in that a ring electrode is joined to the outer circumference of the hollow tube, at least one lead-out electrode is joined to an outer edge of the ring electrode, and the ring electrode comprises a core portion of electrode of platinum or platinum alloy and a thick portion of platinum or platinum alloy or of a metallic material other than platinum or platinum alloy, provided at an outer side of the core portion of electrode.

Abstract: There is provided a method for electrically energizing and heating a platinum or platinum-alloy composite tube structure having a structure including a first main tube, a second main tube, and a branch tube connecting the first main tube and the second main tube, which prevents a local part of the branch tube from being electrically energized and heated in an excessive or insufficient manner.

Abstract: Molten glass has a liquid level located at a higher level than lower ends of an uprising pipe and a downfalling. In addition, a contacting portion of the uprising pipe or the downfalling pipe and a brick receiver on an upstream or downstream pit for supporting the uprising or downfalling pipe, or a joint in the brick receiver is filled with sealing material.

Abstract: A vacuum degassing apparatus includes a lifter to absorb deformation in a vertical direction due to thermal expansion of the vacuum degassing, a slider to absorb thermal expansion of the vacuum degassing vessel in a longitudinal direction thereof, or a thermal expansion absorbing layer to absorb thermal expansion of an uprising pipe and a downfalling pipe in a cross-sectional direction, or a thermal expansion absorbing layer provided along a portion of an outer surface of the vacuum degassing vessel in a height direction.

Abstract: Molten glass has a liquid level located at a higher level than lower ends of an uprising pipe and a downfalling. In addition, a contacting portion of the uprising pipe or the downfalling pipe and a brick receiver on an upstream or downstream pit for supporting the uprising or downfalling pipe, or a joint in the brick receiver is filled with sealing material.

Abstract: Molten glass has a liquid level located at a higher level than lower ends of an uprising pipe and a downfalling. In addition, a contacting portion of the uprising pipe or the downfalling pipe and a brick receiver on an upstream or downstream pit for supporting the uprising or downfalling pipe, or a joint in the brick receiver is filled with sealing material.

Abstract: Before operating a vacuum degassing apparatus for molten glass which has paths for molten glass made of refractory material, fuel is burned by temperature rising burners, and the burned gas is exhausted through an exhaust pipe which communicates to an upper end of a vacuum degassing vessel.