Abstract: A glass melt production apparatus, which comprises a melting vessel, a vacuum degassing apparatus, a first conducting pipe structure connecting the melting vessel and the vacuum degassing apparatus, and a second conducting pipe structure to introduce a glass melt to a forming means, provided downstream the vacuum degassing apparatus; the vacuum degassing apparatus having an uprising pipe through which the glass melt from the melting vessel ascends, a vacuum degassing vessel, and a downfalling pipe through which the glass melt from the vacuum degassing vessel descends; the flow path of the glass melt in the uprising pipe, the vacuum degassing vessel and the downfalling pipe being made of a refractory material; the first conducting pipe structure having an upstream pit to supply the glass melt to the uprising pipe; and the second conducting pipe structure having a downstream pit containing the glass melt from the downfalling pipe; the glass melt production apparatus further comprising a third conducting pipe st

Abstract: To facilitate a preheating operation in a vacuum degassing apparatus having a flow path of a glass melt in an uprising pipe, a vacuum degassing vessel and a downfalling pipe constituted by a refractory material. Flow of a glass melt G between a melting vessel 100 and an upstream pit 210 of a first conducting pipe structure connected to a vacuum degassing vessel 320 is shut off, and in a state where the flow of the glass melt G in a by-pass 500 for the glass melt G is shut off by a first closing means 220, a combustion gas from preheating burners 530, 540 is introduced to the by-pass 500 to preheat the flow path of the glass melt G in an uprising pipe 330, the vacuum degassing vessel 320 and a downfalling pipe 340.

Abstract: It is an object of the present invention to provide a vacuum degassing apparatus configured so as to be capable of carrying out more simply exchange operation for an extension pipe made of heat-resisting metal and immersed in molten glass. The present invention includes a vacuum housing, a vacuum vessel, an introduction pipe and a discharge pipe which are assembled by a plurality of bricks, and an extension pipe connected to at least one of the introduction pipe and the discharge pipe and made of heat-resisting metal. The extension pipe is constituted by a base end portion, a body portion formed so as to be continuous to the base end portion, and a sealing flange extending from an outer peripheral side of the body portion.

Abstract: 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.

Abstract: It is an object of the present invention to provide a vacuum degassing apparatus configured so as to be capable of carrying out more simply exchange operation for an extension pipe made of heat-resisting metal and immersed in molten glass. The present invention includes a vacuum housing, a vacuum vessel, an introduction pipe and a discharge pipe which are assembled by a plurality of bricks, and an extension pipe connected to at least one of the introduction pipe and the discharge pipe and made of heat-resisting metal. The extension pipe is constituted by a base end portion, a body portion formed so as to be continuous to the base end portion, and a sealing flange extending from an outer peripheral side of the body portion.

Abstract: A conduit structure for molten glass, a conduit system for molten glass, a vacuum degassing apparatus and a method for vacuum-degassing molten glass by use of the vacuum degassing apparatus, which are capable of effectively removing components eluted from a refractory brick forming a conduit for molten glass, foreign substances generated in the interface between molten glass and a platinum wall surface forming a conduit for molten glass, a bubble remaining in a surface layer of molten glass, a glass material denatured by volatilization, and the like, are provided.

Abstract: The present invention provides a new method for airtightly joining a hollow tube made of a reinforced platinum and a flange made of platinum or a platinum alloy, which prevents decreasing of mechanical strength of the hollow tube made of a reinforced platinum due to its joining with a flange. A method for airtightly joining a hollow tube made of a reinforced platinum with a flange made of platinum or a platinum alloy, which is a method for airtightly joining the outer periphery of a hollow tube made of a reinforced platinum produced by dispersing metal oxides in platinum or a platinum alloy, with a flange made of platinum or a platinum alloy, the method comprising a step of shrink-fitting a ring made of platinum or a platinum alloy to the outer periphery of the hollow tube, a step of heating the hollow tube to which the ring is shrink-fit at from 1,150 to 1,450° C. for from 1 to 10 hours, and a step of welding the flange made of platinum or a platinum alloy to the outer periphery of the ring.

Abstract: The present invention provides a new method for airtightly joining a hollow tube made of a reinforced platinum and a flange made of platinum or a platinum alloy, which prevents decreasing of mechanical strength of the hollow tube made of a reinforced platinum due to its joining with a flange. A method for airtightly joining a hollow tube made of a reinforced platinum with a flange made of platinum or a platinum alloy, which is a method for airtightly joining the outer periphery of a hollow tube made of a reinforced platinum produced by dispersing metal oxides in platinum or a platinum alloy, with a flange made of platinum or a platinum alloy, the method comprising a step of shrink-fitting a ring made of platinum or a platinum alloy to the outer periphery of the hollow tube, a step of heating the hollow tube to which the ring is shrink-fit at from 1,150 to 1,450° C. for from 1 to 10 hours, and a step of welding the flange made of platinum or a platinum alloy to the outer periphery of the ring.

Abstract: The present invention provides a new method for airtightly joining a hollow tube made of a reinforced platinum and a flange made of platinum or a platinum alloy, which prevents decreasing of mechanical strength of the hollow tube made of a reinforced platinum due to its joining with a flange. A method for airtightly joining a hollow tube made of a reinforced platinum with a flange made of platinum or a platinum alloy, which is a method for airtightly joining the outer periphery of a hollow tube made of a reinforced platinum produced by dispersing metal oxides in platinum or a platinum alloy, with a flange made of platinum or a platinum alloy, the method comprising a step of shrink-fitting a ring made of platinum or a platinum alloy to the outer periphery of the hollow tube, a step of heating the hollow tube to which the ring is shrink-fit at from 1,150 to 1,450° C. for from 1 to 10 hours, and a step of welding the flange made of platinum or a platinum alloy to the outer periphery of the ring.

Abstract: A vacuum degassing apparatus for molten glass includes a vacuum housing which is evacuated to be depressurized therein; a vacuum degassing vessel which is provided in the vacuum housing to vacuum-degas molten glass as the molten glass flows therein; an uprising pipe which connects to the vacuum degassing vessel, and sucks and draws up undegassed molten glass to introduce the undegassed molten glass into the vacuum degassing vessel; and a downfalling pipe which connects to the vacuum degassing vessel and draws down the degassed molten glass from the vacuum degassing vessel to discharge the degassed molten glass. The cross sectional area of the path at the upper end portion of the uprising pipe is larger than the cross sectional area of the path at the lower end portion of the uprising pipe.

Abstract: A conduit structure for molten glass, a conduit system for molten glass, a vacuum degassing apparatus and a method for vacuum-degassing molten glass by use of the vacuum degassing apparatus, which are capable of effectively removing components eluted from a refractory brick forming a conduit for molten glass, foreign substances generated in the interface between molten glass and a platinum wall surface forming a conduit for molten glass, a bubble remaining in a surface layer of molten glass, a glass material denatured by volatilization, and the like, are provided.

Abstract: The present invention provides a new method for airtightly joining a hollow tube made of a reinforced platinum and a flange made of platinum or a platinum alloy, which prevents decreasing of mechanical strength of the hollow tube made of a reinforced platinum due to its joining with a flange. A method for airtightly joining a hollow tube made of a reinforced platinum with a flange made of platinum or a platinum alloy, which is a method for airtightly joining the outer periphery of a hollow tube made of a reinforced platinum produced by dispersing metal oxides in platinum or a platinum alloy, with a flange made of platinum or a platinum alloy, the method comprising a step of shrink-fitting a ring made of platinum or a platinum alloy to the outer periphery of the hollow tube, a step of heating the hollow tube to which the ring is shrink-fit at from 1,150 to 1,450° C. for from 1 to 10 hours, and a step of welding the flange made of platinum or a platinum alloy to the outer periphery of the ring.

Abstract: A vacuum degassing apparatus for molten glass includes a vacuum housing which is evacuated to be depressurized therein; a vacuum degassing vessel which is provided in the vacuum housing to vacuum-degas molten glass as the molten glass flows therein; an uprising pipe which connects to the vacuum degassing vessel, and sucks and draws up undegassed molten glass to introduce the undegassed molten glass into the vacuum degassing vessel; and a downfalling pipe which connects to the vacuum degassing vessel and draws down the degassed molten glass from the vacuum degassing vessel to discharge the degassed molten glass. The cross sectional area of the path at the upper end portion of the uprising pipe is larger than the cross sectional area of the path at the lower end portion of the uprising pipe.

Abstract: A vacuum degassing apparatus for molten glass includes a vacuum housing; a vacuum degassing vessel provided in the vacuum housing; an uprising pipe which connects to the vacuum degassing vessel; and a downfalling pipe which connects to the vacuum degassing vessel. The vacuum housing has an accommodating portion to accommodate the uprising pipe and an accommodating portion to accommodate the downfalling pipe, at least one of which is divided horizontally into a plurality of sections to form a plurality of divided rooms juxtaposed in the vertical direction, and the respective divided rooms are provided with a pressure controller to control the pressures of the respective divided rooms independently.

Abstract: A vacuum degassing apparatus for molten glass, comprising: a vacuum housing which is evacuated to be depressurized therein; a vacuum degassing vessel which is provided in the vacuum housing to vacuum-degas molten glass as the molten glass flows therein; an uprising pipe which connects to the vacuum degassing vessel, and sucks and draws up undegassed molten glass to introduce the undegassed molten glass into the vacuum degassing vessel; and a downfalling pipe which connects to the vacuum degassing vessel and draws down the degassed molten glass from the vacuum degassing vessel to discharge the degassed molten glass; wherein the cross sectional area of the path at the upper end portion of said uprising pipe is larger than the cross sectional area of the path at the lower end portion of said uprising pipe.

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 for molten glass, comprising:

Abstract: A vacuum degassing apparatus for molten glass, comprising:

Abstract: A vacuum degassing apparatus for molten glass according to the present invention comprises a vacuum housing where a vacuum is created; a vacuum degassing vessel housed in the vacuum housing to degas the molten glass; an introduction device communicated to the vacuum degassing vessel so as to introduce untreated molten glass into the vacuum degassing vessel, or preferably an uprising pipe; and a discharge device to discharge treated molten glass from the vacuum degassing vessel, or preferably a downfalling pipe. In the apparatus, at least a portion of at least one of the vacuum degassing vessel, the uprising pipe and the downfalling pipe that directly contact with the molten glass is constituted by refractory material having a porosity of not greater than 5%. The apparatus can increase quantity of flow of the molten glass and consequently a degassing throughput of the molten glass in comparison with prior art, having the same size and the same pressure loss.

Abstract: A vacuum degassing apparatus comprises a path made of dense refractory bricks, the path including an inner surface brick layer, the refractory bricks in the inner surface brick layer having a flatness of 0.5 mm on contacting surfaces with one anther, and the path including a backup brick layer and a ramming material filling layer besides the inner surface brick layer.