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 backup structure for an uprising pipe or a downfalling pipe of a vacuum degassing apparatus including the uprising pipe, a vacuum degassing vessel and the downfalling pipe, comprises the uprising pipe or the downfalling being made of platinum or a platinum alloy and having refractory bricks disposed therearound; and the refractory bricks having a thermal expansion relief member disposed on a top end thereof, the thermal expansion relief member comprising a material selected from a metal material and a ceramic material having a creep strength (JIS Z2271: 1993) of 35 MPa or above at 760° C.

Abstract: A backup structure for hollow tube made of platinum or a platinum alloy in which glass exudation from bricks employed for the backup is prevented, is provided and a vacuum degassing apparatus and a glass producing apparatus employing such a backup structure are provided. A backup structure for hollow tube made of platinum or platinum alloy, which is used in a high-temperature environment, which contains a fused cast refractory layer provided along an outer surface of the hollow tube made of platinum or a platinum alloy, wherein at least in a portion of the fused cast refractory layer in contact with the outer surface of the hollow tube, the component ratio of fused cast refractories containing at most 10 mass % of matrix glass phase, is at least 50 vol %.

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 backup structure for a pipe for feeding a molten substance of high temperature has a pipe and a thermal insulation material surrounding the pipe wherein the pipe is provided with a plurality of projections on its outer periphery at predetermined intervals, and each of the productions is held at its both sides by the thermal insulation material.