JP6520375B2 - Molten glass transfer device - Google Patents

Description

  The present invention relates to a molten glass transfer apparatus having a tube made of platinum or a platinum alloy through which molten glass flows.

  At the time of shaping | molding of glass articles | goods, such as a glass ribbon, the molten glass obtained by fuse | melting glass-making feedstock with a glass melting furnace is supplied to a shaping | molding part through various processes, such as a clarification process and a stirring process. At this time, the molten glass in the glass melting furnace flows through the predetermined flow path and is transferred to the forming portion, and as the flow path, for example, heat resistance and oxidation resistance as disclosed in Patent Document 1 From the viewpoint of securing the properties, it is general to use a pipe made of platinum, platinum alloy or the like.

JP, 2013-216535, A

  By the way, in the molten glass transfer device as described above, it is possible to adjust the temperature of the molten glass flowing in the tube, and hence the flow rate, by resistance heating (Joule heat) generated by applying an electric current to the tube made of platinum or platinum alloy. is there.

  Moreover, in the molten glass transfer apparatus of the said patent document 1, the flow path of molten glass is formed with several pipe material. In such a configuration, by individually controlling the current supplied to each tube, temperature control for each section corresponding to each tube in the flow path of the molten glass becomes possible, and a more preferable temperature of the molten glass flowing through the flow path Although control can be realized, in that case, it becomes an issue how to secure the electrical insulation between the pipes.

  The present invention has been made to solve the above-mentioned problems, and an object thereof is to electrically control the temperature of each of a plurality of tubes constituting a flow path of molten glass. An object of the present invention is to provide a molten glass transfer device that can be insulated.

  The molten glass transfer apparatus for solving the above problems comprises at least two platinum or platinum alloy pipes having a flange at an axial end, and melting is carried out by the pipes arranged side by side with the flanges facing each other. The flow path which distribute | circulates glass is comprised, and the insulating layer for aiming at the electrical insulation between each said piping material is provided between said flanges of each said piping material.

  According to this configuration, the insulating layer is provided between the flanges of the pipes facing each other, and the insulating layer is used to achieve electrical insulation between the pipes. For this reason, control of the electric current sent for every pipe material is attained, As a result, temperature control for every pipe material is attained.

In the molten glass transfer apparatus, it is preferable that the insulating layer includes a fiber assembly made of an insulating material.
According to this configuration, it is possible to achieve electrical insulation between the tubes by the insulating layer made of the fiber assembly. In addition, since the elasticity of the fiber assembly allows the expansion and contraction of each tube, deformation and breakage of the tube and the positional deviation can be suppressed.

  In the molten glass transfer device, the fiber assembly is any of a cloth-like member obtained by knitting a fibrous refractory, a paper-like member obtained by forming the fibrous refractory, and a blanket-like member obtained by compression molding a fibrous refractory. It is preferable to consist of.

  According to this configuration, the fiber assembly comprises any one of a cloth-like member in which a fibrous refractory is woven, a paper-like member in which the fibrous refractory is formed, and a blanket-like member in which the fibrous refractory is compression molded. , They are lightweight and flexible. Therefore, the workability at the time of assembling | attaching a fiber assembly between the flanges of each pipe material can be improved. Further, since the cross-like member, the paper-like member and the blanket-like member can be manufactured relatively inexpensively, they can contribute to the reduction of the manufacturing cost of the molten glass transfer device.

  In the molten glass transfer device, a glass inflow promoting portion for promoting the inflow of molten glass flowing through the flow path is formed between the flanges of the pipe material, and flows into the glass inflow promoting portion as the insulating layer. It is preferable to provide a glass which has been cooled and solidified.

  According to this configuration, the molten glass is drawn between the flanges according to the flange shape, and the glass solidified between the flanges forms an insulating layer between the tubes, so a member for insulating the tubes is particularly required. In addition, it can contribute to the reduction of manufacturing costs.

In the molten glass transfer device, it is preferable that the glass inflow promoting portion includes a tapered portion formed at a bent portion where the tubular portion of the pipe member shifts to the flange.
According to this configuration, since the glass inflow promoting portion includes the tapered portion formed at the bent portion where the tubular portion of the pipe moves from the cylindrical portion to the flange, the molten glass flowing in the pipe is suitably flowed into the glass inflow promoting portion. Is possible.

In the molten glass transfer device, it is preferable that the glass inflow promoting portion includes a step portion formed at a bent portion where the tubular portion of the pipe member is shifted to the flange.
According to this configuration, since the glass inflow promoting portion includes the step portion formed at the bent portion where the tubular portion of the pipe moves from the cylindrical portion to the flange, the molten glass flowing in the pipe is suitably made to flow into the glass inflow promoting portion. Is possible.

  According to the molten glass transfer apparatus of the present invention, it is possible to electrically insulate the respective pipes in order to enable temperature control of each of the plurality of pipes constituting the flow path of the molten glass.

It is a schematic block diagram of the molten glass transfer apparatus in embodiment. It is explanatory drawing for demonstrating the manufacturing method of the molten glass transfer apparatus of the form. It is a schematic diagram for demonstrating the manufacturing method of the molten glass transfer apparatus of the form. It is explanatory drawing for demonstrating the manufacturing method of the molten glass transfer apparatus of another example. It is a schematic diagram which shows the boundary part of the pipes in the molten glass transfer apparatus of another example. It is a schematic diagram which shows the boundary part of the pipes in the molten glass transfer apparatus of another example. It is a schematic diagram which shows the boundary part of the pipes in the molten glass transfer apparatus of another example.

Hereinafter, an embodiment of a molten glass transfer apparatus will be described.
As shown in FIG. 1, the molten glass transfer apparatus 10 of this embodiment is used in a manufacturing apparatus for manufacturing a glass article such as a glass ribbon, and a molten glass obtained by melting a glass material in a glass melting furnace M is used. For example, it is for transferring to a forming unit. The molten glass transferred from the molten glass transfer device 10 to the forming unit is formed into a glass article such as a glass ribbon in the forming unit.

  The molten-glass transfer apparatus 10 is equipped with the 1st and 2nd pipings 11 and 12 which comprise the flow path F through which molten glass distribute | circulates. The first and second tubes 11 and 12 are both formed of platinum or platinum alloy. The first and second tubular members 11 and 12 have a cylindrical shape, and flanges 11a and 11b are formed on both axial ends of the first tubular member 11, and flanges on both axial ends of the second tubular member 12 12a and 12b are respectively formed. In the present embodiment, the flanges 11 a and 11 b of the first pipe member 11 have a flat plate shape perpendicular to the axis of the first pipe member 11. Similarly, the respective flanges 12 a and 12 b of the second pipe member 12 also have a flat plate shape perpendicular to the axis of the second pipe member 12. Then, one flange 11 b of the first pipe member 11 and one flange 12 a of the second pipe member 12 face each other so that the plate surfaces thereof are substantially parallel, and the first and second pipe members 11, 12 are juxtaposed in the axial direction.

  An insulating layer 13 is provided between the flanges 11 b and 12 a to provide electrical insulation between the first pipe material 11 and the second pipe material 12. The flanges 11b and 12a are fixed to each other while securing electrical insulation by means of a bolt or the like (not shown).

  In the present embodiment, the insulating layer 13 is formed of a sheet-like fiber assembly made of a refractory material such as alumina or silica. More specifically, as the insulating layer 13, a cloth-like member obtained by knitting a fibrous refractory, a paper-like member obtained by forming the fibrous refractory, a blanket-like member obtained by compression molding a fibrous refractory, or the like may be used. Can. In the insulating layer 13, a through hole 13 a having a diameter equal to or larger than the inner diameter of the first and second pipes 11 and 12 is formed corresponding to the flow path F. The diameter of the through hole 13a is more preferably substantially the same as the inner diameter of the first and second tubular members 11 and 12.

  The thickness of the insulating layer 13 (the distance between the flanges 11 b and 12 a) is preferably set to 1 mm or more in consideration of enhancing the insulation between the first and second pipes 11 and 12, In consideration of leakage of molten glass from between the flanges 11b and 12a in which the insulating layer 13 is interposed, it is preferable to set to 100 mm or less. That is, the thickness of the insulating layer 13 is preferably set to 1 mm to 100 mm or less in consideration of both the insulating property and the resistance to leakage of the molten glass. Further, a more preferable setting range of the thickness of the insulating layer 13 is 1.5 to 10 mm, and a further preferable setting range is 2 to 5 mm.

  In the molten glass transfer device 10, it is possible to control the temperature (flow rate) of the molten glass flowing inside by resistance heating (Joule heat) generated by applying an electric current to the first and second pipes 11 and 12 It has become. The current from the power source 14 is supplied to the first and second pipes 11 and 12 through the relay 16 controlled by the control circuit 15, and the relay 16 supplies the current to the first and second pipes 11 and 12. Thus, it is possible to supply current separately and selectively. The connection line from the relay 16 is connected to the flanges 11a, 11b, 12a, 12b of the first and second pipe members 11, 12, respectively.

Next, a method of assembling the insulating layer 13 between the flanges 11 b and 12 a will be described.
As shown in FIG. 2, first, a heating step S1 is performed in which a current is supplied to each of the pipes 11 and 12 to heat the pipes 11 and 12. In the heating step S1, the pipes 11 and 12 expand, and the axial length of the pipes 11 and 12 increases due to the expansion.

  Next, as shown in FIGS. 2 and 3, a sandwiching step S2 is performed in which the insulating layer 13 is sandwiched between the flange 11 b of the first pipe member 11 and the flange 12 a of the second pipe member 12. In the sandwiching step S2, first, the opening on the flange 11a side of the first pipe member 11 abuts the glass supply port on the glass melting furnace M side, and then the insulating layer 13 is sandwiched by the flanges 11b and 12a of the respective pipe members 11 and 12 Be At this time, the insulating layer 13 is sandwiched between the flanges 11 b and 12 a such that the openings 11 c and 12 c at the end of the tubular members 11 and 12 correspond to the through holes 13 a of the insulating layer 13. Further, at this time, the flanges 11 b and 12 a and the insulating layer 13 are in contact without a gap. In addition, it is preferable to temporarily fix the insulating layer 13 to any plate surface of the flanges 11b and 12a before the sandwiching step S2.

  Next, as shown in FIG. 2, a fixing step S3 of fixing the flanges 11b and 12a to each other by the bolt or the like is performed. As a result, the first and second pipes 11 and 12 are fixed to each other, and a flow path F in which the molten glass flows is formed inside the pipes 11 and 12.

Next, the operation of the present embodiment will be described.
The temperature of the molten glass flowing in each of the pipes 11 and 12 (flow path F) is suitably adjusted by controlling the value of the current flowing through each pipe 11 and 12 for each of the pipes 11 and 12 by the control circuit 15 and the relay 16. It becomes possible. And by adjusting the temperature of a molten glass, adjustment of the flow volume of the molten glass which distribute | circulates the flow path F is attained. The individual heating of the tubular members 11 and 12 by this current is possible by ensuring the electrical insulation between the first and second tubular members 11 and 12 by the insulating layer 13 interposed between the flanges 11b and 12a. It has become.

  Further, in the present embodiment, at the time of assembling the respective tubular members 11, 12 and the insulating layer 13, after the respective tubular members 11, 12 are thermally expanded in the heating step S1, the flanges 11b of the respective tubular members 11, 12 in the sandwiching step S2, The insulating layer 13 is sandwiched by 12a. For this reason, in consideration of linear expansion in the axial direction of each of the pipes 11, 12, there is no need to dispose the pipes 11, 12 while providing a gap, and the assembling of the pipes 11, 12 and the insulating layer 13 is easy. It becomes.

Next, characteristic effects of the present embodiment will be described.
(1) The pipes 11 and 12 constituting the flow path F of the molten glass are arranged side by side with their flanges 11b and 12a facing each other, and between the flanges 11b and 12a An insulating layer 13 is provided to provide electrical insulation therebetween. As a result, since the insulation layer 13 electrically insulates each of the pipes 11, 12, it is possible to control the current flowing through each of the pipes 11, 12 individually, and as a result, the temperature of each of the pipes 11, 12 Adjustment is possible.

  (2) The insulating layer 13 is a fiber assembly made of a material having an insulating property, and the electrical insulation between the tubes 11 and 12 can be achieved by the insulating layer 13 made of the fiber assembly. In addition, when the insulating layer 13 made of a fiber assembly is formed to have a predetermined thickness or more, the insulating layer 13 functions as a spacer that allows expansion and contraction of each of the tubes 11 and 12 because it has appropriate elasticity. It can be done. That is, it is possible to suppress deformation and breakage, positional deviation and the like of the pipe members 11 and 12. In addition, as a material used for this fiber assembly, it is preferable to use the alumina, the silica, etc. which were excellent in fire resistance.

  (3) The fiber assembly constituting the insulating layer 13 is any of a cloth-like member obtained by knitting a fibrous refractory, a paper-like member obtained by forming the fibrous refractory, and a blanket-like member obtained by compression molding the fibrous refractory. It is preferable to be made of a gum. Since these cross-like members, paper-like members and blanket-like members are light in weight and high in flexibility, the workability when assembling the insulating layer 13 (fiber assembly) between the flanges 11b and 12a of the respective tubes 11 and 12 Can be improved. In addition, since the cross-like member, the paper-like member and the blanket-like member can be manufactured relatively inexpensively, they can contribute to the reduction of the manufacturing cost of the molten glass transfer apparatus 10.

The above embodiment may be modified as follows.
· As shown in FIG. 4, in assembling the pipes 11 and 12 and the insulating layer 13, the pipes 11 and 12 are heated after the sandwiching step S 11 in which the flanges 11 b and 12 a of the pipes 11 and 12 sandwich the insulating layer 13. The heating step S12 may be performed. In this case, in the sandwiching step S11, between the flanges 11b and 12a or between the flange 11a of the first tube 11 and the glass supply port on the glass melting furnace M side, in the axial direction of the tubes 11 and 12 It is preferable to provide a gap in consideration of the linear expansion of the Further, in this case, in the heating step S12 after the sandwiching step S11, the insulating layer 13 is compressed by the flanges 11b and 12a by the linear expansion in the axial direction of each of the pipes 11 and 12, but the insulating layer 13 after the compression is performed. It is preferable to set the thickness of 1 mm or more in consideration of enhancing the insulation between the pipes 11 and 12. Further, in consideration of leakage of molten glass from between the flanges 11b and 12a, it is preferable to set the thickness of the insulating layer 13 after compression to 10 mm or less. Furthermore, in consideration of the tolerance of the linear expansion in the axial direction of each of the pipes 11 and 12 in the heating step S12, the thickness of the insulating layer 13 after compression is preferably set to 5 mm or more. That is, in the case where the heating step S12 is performed after the sandwiching step S11, the thickness of the insulating layer 13 after compression is 5 mm in consideration of all of the insulation property, the leakage resistance of the molten glass, and the linear expansion tolerance. As mentioned above, it is preferable to set to 10 mm or less.

In the embodiment described above, the insulating layer 13 is a fiber assembly, but may be changed to other than a fiber assembly as long as electrical insulation between the flanges 11b and 12a can be achieved.
For example, as shown in FIG. 5, a glass inflow promoting portion 20 is formed between the flanges 11b and 12a of the pipes 11 and 12 to promote the inflow of molten glass flowing through the flow path F, and the glass inflow promoting portion The glass plug 21 which has flowed into 20 and has been cooled and solidified may be configured as an insulating layer.

  In the example shown in the figure, tapered portions 11d and 12d are formed at bent portions where the tubular portions (body portions) of the respective tubular members 11 and 12 transition to the flanges 11b and 12a. Each of the tapered portions 11d and 12d is formed over the entire circumference of the inner peripheral edge portion of the flanges 11b and 12a, and has an inclined shape in which the diameter is expanded outward in the axial direction. In the flanges 11b and 12a, flat portions 23 are formed on the outer peripheral side of the tapered portions 11d and 12d. The flat portion 23 has a flat plate shape perpendicular to the axes of the first and second pipes 11 and 12. The flat portion 23 of the flange 11b and the flat portion 23 of the flange 12a are configured to be substantially parallel to each other, and are opposed to each other at a predetermined interval. The flanges 11b and 12a are fixed to each other while securing electrical insulation by bolts or the like (not shown) as in the above embodiment.

  In such a configuration, in the assembled state in which the flanges 11b and 12a of the respective pipe members 11 and 12 face each other, the opposing distance between the tapered portions 11d and 12d of the flanges 11b and 12a is narrowed toward the outer peripheral side. ing. That is, since the opposing space | interval of each taper part 11d, 12d is wide in the inner peripheral side, the molten glass which flows through the flow path F can be easily flowed in between each taper part 11d, 12d. That is, in the same example, the glass inflow promotion part 20 which promotes inflow of the molten glass which distribute | circulates the flow path F by each taper part 11d and 12d is formed.

  In the molten glass transfer device 10 configured as described above, when the molten glass is caused to flow through the flow path F formed by the first and second pipe members 11 and 12, the molten glass becomes each of the flanges 11b and 12a. It flows in between the taper parts 11 d and 12 d (that is, the glass inflow promoting part 20). The molten glass flowing into the space between the tapered portions 11 d and 12 d is cooled toward the outer peripheral side, and solidified between the tapered portions 11 d and 12 d to form a glass plug 21. Between the flanges 11b and 12a, the molten glass flowing into the space between the tapered portions 11d and 12d has an increase in inflow resistance because the opposing distance between the tapered portions 11d and 12d becomes narrower toward the outer periphery. In the case of the first embodiment, it is more difficult to intrude into the outer peripheral side than the tapered portions 11d and 12d (glass inflow promoting portion 20). Further, since each taper portion 11d, 12d is formed over the entire circumference of the inner peripheral edge portion of the flanges 11b, 12a, the glass plug 21 solidified in each of the taper portions 11d, 12d is also the entire circumferential direction. Are formed over the

  According to such a configuration, the glass plug 21 as an insulating layer for achieving electrical insulation between the tubular members 11 and 12 between the tapered portions 11d and 12d of the flanges 11b and 12a (glass inflow promoting portion 20) As a result, it becomes possible to control the current supplied to each of the tubes 11 and 12 individually, and as a result, it is possible to adjust the temperature of each tube 11 and 12. In addition, the molten glass is drawn between the flanges 11b and 12a by the shape of the flanges 11b and 12a, and the glass plug 21 solidified between the flanges 11b and 12a constitutes the insulating layer between the tubes 11 and 12, It is possible to contribute to the reduction of the manufacturing cost without requiring a special member for insulating between the pipe members 11 and 12. Further, since the space between the flanges 11 b and 12 a is closed by the glass plug 21, it is possible to suppress the molten glass flowing in the flow path F from leaking between the flanges 11 b and 12 a to the outside. Further, since the glass inflow promoting portion 20 includes the tapered portions 11d and 12d formed at the bending portions moving from the cylindrical portions of the tubes 11 and 12 to the flanges 11b and 12a, the molten glass flowing in the tubes 11 and 12 is It is possible to suitably flow the glass inflow promoting portion 20.

  In the example of FIG. 5, as shown in FIG. 6, the insulating layer 13 (fiber assembly made of a material having insulation properties) of the above embodiment is interposed between the flat portions 23 of the flanges 11b and 12a. May be Thereby, the insulation between the flanges 11b and 12a can be ensured more reliably. In addition, the insulating layer may be made of a composite material in which molten glass penetrates into the fiber assembly.

  Further, in the example of FIG. 5, the glass inflow promoting portion 20 is formed by the tapered portions 11d and 12d formed on the flanges 11b and 12a, but other than this, for example, the flanges 11b and 12a as shown in FIG. You may form the glass inflow promotion part 20 by the level | step-difference parts 11e and 12e which were formed. The flanges 11 b and 12 a are configured to have a wider facing distance than the flat portion 23 between the step portions 11 e and 12 e. With such a configuration, the same effect as the example of FIG. 5 can be obtained. Further, in this configuration, since the glass inflow promoting portion 20 includes the step portions 11e and 12e formed at the bent portions where the cylindrical portions of the pipes 11 and 12 shift to the flanges 11b and 12a, It is possible to suitably flow the flowing molten glass into the glass inflow promoting unit 20.

Moreover, you may comprise the glass inflow promotion part 20 in the shape which made one part of the level | step-difference part taper-shaped (inclined surface) combining FIG. 5 and FIG.
Moreover, although the taper parts 11d and 12d were respectively formed in both flanges 11b and 12a in the example of FIG. 5, it is not specifically limited to this, A taper part is formed only in any one of flanges 11b and 12a Alternatively, the other flanges 11b and 12a may be in the form of a flat plate without a tapered portion as in the above embodiment. Moreover, in the example of FIG. 5, although the flanges 11b and 12a have the flat part 23 in the outer peripheral side of taper part 11d, 12d, it is good also as a shape which abbreviate | omitted this flat part 23. FIG.

-In heating process S1 of the said embodiment, although each pipe material 11 and 12 is heated by sending an electric current, you may heat each pipe material 11 and 12 by other means.
In the above embodiment, although not particularly mentioned, the first and second pipes 11 and 12 may be disposed coaxially, and in addition to that, the second pipe 11 and the second pipe 11 may be disposed. The pipe material 12 may be disposed at an angle. Even when the second pipe member 12 is arranged to be inclined with respect to the first pipe member 11, it is preferable to configure the flanges 11b and 12a substantially in parallel with each other.

The number of the pipes 11 and 12 constituting the flow path F of the molten glass transfer device 10 is not limited to two in the above embodiment, and may be changed to three or more depending on the configuration.
Although not particularly mentioned in the above embodiment, the insulating layer 13 may be further provided not only between the pipes 11 and 12 but also between other pipes connected with the pipes 11 and 12. For example, the insulating layer 13 may be further provided between the glass melting furnace M and the pipe member 11, and the insulating layer 13 may be further provided between the pipe member 12 and the downstream equipment (not shown).

  -In the manufacturing process of the glass article of the said embodiment, you may provide arbitrary processes from the glass melting furnace M to a shaping | molding part. For example, it is possible to further provide processes such as a clear section for degassing the molten glass by heating it and a stirring section for stirring the molten glass, and the molten glass transfer device 10 can be optionally disposed between these processes. Moreover, the molten glass transfer apparatus 10 of the said embodiment may be applied to the glass transfer apparatus used in locations other than between the glass melting furnace M and shaping | molding part in the manufacturing apparatus of a glass article. For example, in a glass article manufacturing apparatus provided with a plurality of melting furnaces, the molten glass transfer apparatus of the present invention may be used as an apparatus for transferring molten glass between the melting furnaces.

Next, technical ideas that can be grasped from the above embodiment and another example will be additionally described below.
(A) The glass inflow promoting portion is formed by a tapered portion formed in the flanges of the mutually opposing pipe members so that the opposing distance is narrowed toward the outer peripheral side. Glass transfer equipment.

  According to this configuration, in the tapered portion that constitutes the glass inflow promoting portion, the inflow resistance of the molten glass is increased toward the outer peripheral side because the facing distance of the flanges is narrower toward the outer peripheral side. For this reason, it becomes possible to make it difficult to infiltrate the molten glass to the outer peripheral side than the glass inflow promoting portion between the flanges.

(B) A manufacturing method for manufacturing the molten glass transfer device according to claim 2;
A heating step of heating each of the pipes;
After the heating step, the sandwiching step of sandwiching the insulating layer between the flanges of the respective tube members.

  According to this configuration, it is not necessary to dispose the pipes while providing gaps in consideration of the linear expansion of the pipes, and the assembly of the pipes and the insulating layer becomes easy.

  DESCRIPTION OF SYMBOLS 10 ... Molten glass transfer apparatus, 11 ... 1st pipe material, 12 ... 2nd pipe material, 11a, 11b, 12a, 12b ... flange, 11d, 12d ... taper part, 11e, 12e ... level | step-difference part, 13 ... insulating layer, 20: Glass inflow promoting portion, 21: Glass stopper as an insulating layer, F: Flow path.

Claims (5)

At least two platinum or platinum alloy tubes with flanges at their axial ends,
A flow path for circulating the molten glass is constituted by each of the pipes arranged in parallel with the flanges facing each other,
Between the flanges of the pipes, an insulating layer is provided to provide electrical insulation between the pipes ;
A molten glass transfer apparatus comprising: a fiber assembly made of an insulating material as the insulating layer . The fiber assembly is characterized in that it comprises any one of a cloth-like member obtained by knitting a fibrous refractory, a paper-like member obtained by forming the fibrous refractory, and a blanket-like member obtained by compression molding of the fibrous refractory. The molten glass transfer apparatus according to claim 1 . Between the flanges of the pipe material, a glass inflow promoting portion is formed which promotes the inflow of molten glass flowing through the flow path,
Wherein the insulating layer, the molten glass transport apparatus according to claim 1 or 2, characterized in that it comprises a glass that has been cooled and solidified flows into the glass flowing promoting portion. The molten glass transfer apparatus according to claim 3 , wherein the glass inflow promoting portion includes a tapered portion formed at a bent portion where the tubular portion of the pipe member shifts to the flange. The molten glass transfer apparatus according to claim 3 , wherein the glass inflow promoting portion includes a step portion formed at a bent portion where the tubular portion of the pipe member is shifted to the flange.