Conduit structure for molten glass, vacuum degassing apparatus, vacuum degassing method for molten glass and process for producing glass products employing said conduit structure

摘要

A conduit structure for molten glass, in which molten glass is flown through a double-pipe structure, with little stress loading even for a long time operation. A supporting rib connecting an inner pipe and an outer pipe is employed in the double pipe structure having the inner pipe and outer pipe in the conduit structure for molten glass, wherein excessive stress concentration hardly occurs in an inner pipe-joint portion, an outer pipe-joint portion and the rib when the rib is applied with a stress load due to the weight of the inner pipe.

主权项

1. A conduit structure for molten glass comprising a hollow tube made of a metal, the conduit structure having at least a downstream end having a double pipe structure comprising an inner pipe and an outer pipe, wherein a supporting rib is provided between the inner pipe and the outer pipe to bridge the inner pipe and the outer pipe;
wherein the supporting rib has an inner straight portion joined with the outer face of the inner pipe so as to extend along the longitudinal direction of the inner pipe and having a width substantially in a normal direction to the joined face, an outer straight portion joined with the inner face of the outer pipe so as to extend along the longitudinal direction of the outer pipe and having a width substantially in the normal direction to the joined face, and a connecting wall portion extending from the inner straight portion to the outer straight portion to integrate them; and the supporting rib has a concave portion formed along one side edge of the connecting wall portion present between one side end portion of the inner straight portion and one side end portion of the outer straight portion, so that respective ends of said one side edge reach said one side end portions of the respective straight portions via rounded portions, and a concave portion formed along the other side edge of the connecting wall portion present between the other side end portion of the inner straight portion and the other side end portion of the outer straight portion, so that respective ends of said the other side edge reach said the other side end portions of the respective straight portions via rounded portions, and the supporting rib has projecting portions formed on respective ends of the inner straight portion and respective ends of the outer straight portion and continuing to the respective rounded portions.