Feeder

Abstract

Side wall parts 6a, 6b of a feeder 3 include a first side wall part 6a and a second side wall part 6b positioned with a predetermined spacing therebetween. Ceiling parts 7a, 7b of the feeder 3 are each formed from a long fireproof member bridged between the first side wall part 6a and the second side wall part 6b. The ceiling parts 7a, 7b include a first ceiling part 7a and a second ceiling part 7b arranged so as to be adjacent to each other. A first protruding part 9 of the first ceiling part 7a overlaps a second protruding part 10 of the second ceiling part 7b in the vertical direction.

Description

Feeder

[0001] The present invention relates to a feeder capable of flowing molten glass.

[0002] For example, when supplying molten glass to a bushing for forming glass fiber, a forming body for forming sheet glass, or the like, it is necessary to keep the molten glass flowing inside the feeder warm and prevent its temperature from decreasing. As a method for achieving this, a method of heating the molten glass by a heating means disposed in the internal space of the feeder has come to be widely adopted.

[0003] For example, Patent Document 1 discloses a feeder whose peripheral wall is made of refractory material and whose internal space is provided with an electric heating element. The internal space of this feeder includes a bottom, a pair of side walls, and a ceiling covering the upper part of the side walls. The electric heating element is supported by the ceiling and located near the side walls (see Figure 2 of the same document).

[0004] Japanese Patent Application Laid-Open No. 2014-221700

[0005] The interior space of the feeder is kept at a high temperature due to heating by the electric heating element and the heat of the molten glass, which causes creep deformation of the ceiling of the feeder over time.

[0006] The position and posture of the electric heating element supported on the ceiling changes with the deformation of the ceiling, which can cause the electric heating element to come into contact with the side wall of the feeder, potentially damaging the side wall and the electric heating element.

[0007] The present invention has been made in view of the above circumstances, and has as its technical object to suppress creep deformation in the ceiling portion of a feeder.

[0008] (1) The present invention is intended to solve the above-mentioned problems, and is a feeder for circulating molten glass therein, comprising a ceiling portion and a side wall portion supporting the ceiling portion, the side wall portion including a first side wall portion and a second side wall portion arranged at a predetermined interval, the ceiling portion being constituted by a long fireproof member spanning the first side wall portion and the second side wall portion, the ceiling portion including a first ceiling portion and a second ceiling portion arranged adjacent to each other, the first ceiling portion having a first protrusion portion, the second ceiling portion having a second protrusion portion, and the first protrusion portion and the second protrusion portion overlap in the vertical direction.

[0009] According to this configuration, the first and second ceiling sections can be integrated by vertically overlapping the first protruding section of the first ceiling section and the second protruding section of the second ceiling section, thereby increasing the second moment of area of ​​the integrated ceiling sections and making it possible to suppress creep deformation of the first and second ceiling sections.

[0010] (2) In the feeder described in (1) above, the first protrusion may have a first contact surface that faces the second protrusion in the vertical direction, and the second protrusion may have a second contact surface that contacts and overlaps the first contact surface in the vertical direction.

[0011] With this configuration, creep deformation of the first ceiling portion and the second ceiling portion can be effectively suppressed by bringing the first contact surface of the first protrusion associated with the first ceiling portion into contact with the second contact surface of the second protrusion associated with the second ceiling portion.

[0012] (3) The feeder according to (1) or (2) above may further include an electric heating element supported on the ceiling portion and configured to heat the molten glass.

[0013] According to this configuration, creep deformation of the ceiling portion is suppressed, thereby preventing damage to the electric heating element.

[0014] (4) In the feeder described in (3) above, the ceiling portion may have a through hole through which the electric heating element is inserted.

[0015] According to this configuration, the electric heating element can be easily attached to the ceiling portion by the through hole formed in the ceiling portion.

[0016] (5) The feeder described in (4) above may further include a fixing member that fixes the electric heating element inserted into the through hole to the ceiling portion.

[0017] With this configuration, the electric heating element can be reliably fixed to the ceiling.

[0018] According to the present invention, creep deformation in the ceiling portion of the feeder can be suppressed.

[0019] Fig. 2 is a longitudinal cross-sectional view showing a glass fiber manufacturing apparatus. Fig. 3 is a cross-sectional view taken along the line II-II of Fig. 1. Fig. 4 is a perspective view of a first ceiling section. Fig. 5 is a perspective view of a second ceiling section. Fig. 6 is a cross-sectional view of a ceiling section. Fig. 7 is a cross-sectional view of another example of a ceiling section. Fig. 8 is a cross-sectional view of another example of a ceiling section. Fig. 9 is a cross-sectional view illustrating the mode of creep deformation of a conventional ceiling section.

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0021] FIG. 1 is a longitudinal sectional view showing an outline of a glass fiber manufacturing apparatus equipped with a feeder according to the present invention.

[0022] The manufacturing apparatus 1 includes a melting furnace 2 that melts glass raw material Gr to form molten glass Gm, and a feeder 3 that is connected downstream of the melting furnace 2 and allows the molten glass Gm to flow therethrough. Walls that define the melting space of the melting furnace 2 and the flow space of the feeder 3 are made of refractory materials such as bricks.

[0023] An inlet 2a is provided at the upstream end of the melting furnace 2 for introducing glass raw material Gr, which is a mixture of silica sand, limestone, soda ash, cullet, etc., into the furnace. A raw material supply means (not shown), such as a screw feeder, is disposed at the inlet 2a.

[0024] The melting furnace 2 is further provided with a heating device (not shown). As the heating device, for example, a gas burner or an electric heater disposed above the molten glass Gm, or an electric heating device such as an electrode immersed in the molten glass Gm can be used.

[0025] The glass frit Gr introduced from the inlet 2a is melted by heating using a heating device, thereby continuously forming molten glass Gm. The molten glass Gm flows into the feeder 3 from the downstream end of the melting furnace 2. The melting furnace 2 may melt the glass frit Gr only by gas combustion or only by electric heating, or may melt the glass frit Gr by a combination of gas combustion and electric heating.

[0026] A plurality of bushings 4 made of platinum or a platinum alloy are provided at intervals in the longitudinal direction X of the feeder 3, i.e., the flow direction of the molten glass Gm, below the feeder 3. Each bushing 4 is provided with a plurality of bushing nozzles (not shown). Each nozzle causes the molten glass Gm to flow down and form glass fibers Gf. The molten glass Gm flowing down from each nozzle is formed into glass fibers Gf (glass filaments) having a predetermined diameter while being stretched downward. A sizing agent is applied to the glass fibers Gf, and then the plurality of glass fibers Gf are bundled together to form glass strands.

[0027] As shown in FIG. 2, the feeder 3 includes a bottom 5, a pair of side wall portions 6a and 6b fixed to the upper portion of the bottom 5, a ceiling portion 7 supported by the side wall portions 6a and 6b, and electric heating elements 8a and 8b supported by the ceiling portion 7 and serving as heating devices for heating the molten glass Gm.

[0028] The bottom portion 5 , together with parts of the side wall portions 6 a and 6 b , forms a flow path for circulating the molten glass Gm along the longitudinal direction X of the feeder 3 .

[0029] The pair of side walls 6a, 6b are arranged at a predetermined interval in the width direction Y of the feeder 3. The side walls 6a, 6b include a first wall located at one end of the feeder 3 in the width direction Y and a second side wall 6b located at the other end of the feeder 3 in the width direction Y. Each of the side walls 6a, 6b has a support surface 6c that supports the ceiling portion 7.

[0030] 2 to 4, the ceiling portion 7 is formed of a long fire-resistant member that spans the first side wall portion 6a and the second side wall portion 6b. Each ceiling portion 7 is formed in a plate shape, but is not limited to this shape. The length dimension L of the ceiling portion 7 is greater than the distance D between the inner surfaces of the pair of side walls 6a, 6b. As a result, one longitudinal end of the ceiling portion 7 is supported by the support surface 6c of the first side wall portion 6a, and the other longitudinal end of the ceiling portion 7 is supported by the support surface 6c of the second side wall portion 6b.

[0031] 5, the upper portion of the feeder 3 is closed by arranging a plurality of ceiling sections 7. Hereinafter, of the plurality of ceiling sections 7, one of two adjacent ceiling sections 7a, 7b will be referred to as a first ceiling section 7a, and the other will be referred to as a second ceiling section 7b.

[0032] 3 to 5, each of the ceiling portions 7a, 7b has protrusions 9, 10 that protrude along the width direction W (hereinafter referred to as "width-direction protrusions") and protrusions 11, 12 that protrude along the vertical direction (hereinafter referred to as "vertical direction protrusions") 11, 12. The width direction W of the ceiling portions 7a, 7b is the same as the longitudinal direction X of the feeder 3.

[0033] Hereinafter, the widthwise protrusion 9 of the first ceiling portion 7a will be referred to as the "first widthwise protrusion," and the widthwise protrusion 10 of the second ceiling portion 7b will be referred to as the "second widthwise protrusion." Furthermore, the vertical protrusion 11 of the first ceiling portion 7a will be referred to as the "first vertical protrusion," and the vertical protrusion 12 of the second ceiling portion 7b will be referred to as the "second vertical protrusion."

[0034] 5, the first ceiling portion 7a and the second ceiling portion 7b are arranged side by side with their tops and bottoms facing inversely. That is, the first ceiling portion 7a is arranged so that the first vertical protrusion 11 is located on the upper side and the first widthwise protrusion 9 is located on the lower side. Conversely, the second ceiling portion 7b is arranged so that the second widthwise protrusion 10 is located on the upper side and the second vertical protrusion 12 is located on the lower side.

[0035] The first widthwise protrusion 9 is arranged to overlap in the vertical direction with the second widthwise protrusion 10. Specifically, the first widthwise protrusion 9 of the first ceiling portion 7a is arranged to be adjacent to the second vertical protrusion 12 of the second ceiling portion 7b. The first vertical protrusion 11 of the first ceiling portion 7a is arranged to be adjacent to the second widthwise protrusion 10 of the second ceiling portion 7b.

[0036] The first width direction protrusion 9 includes a pair of protrusions protruding from one side and the other side of the first ceiling portion 7a in the width direction W. Similarly, the second width direction protrusion 10 includes a pair of protrusions protruding from one side and the other side of the second ceiling portion 7b in the width direction W.

[0037] The first widthwise protrusion 9 has a contact surface (hereinafter referred to as the "first contact surface") 9a ​​that faces the second widthwise protrusion 10 in the vertical direction. The second widthwise protrusion 10 has a contact surface (hereinafter referred to as the "second contact surface") 10a that comes into contact with and overlaps the first contact surface 9a in the vertical direction. Each contact surface 9a, 10a is configured as a flat surface that extends along the horizontal direction perpendicular to the vertical direction.

[0038] 5, the first widthwise protrusion 9 and the second widthwise protrusion 10 have side surfaces 9b, 10b facing the width direction W. The side surface 9b of the first widthwise protrusion 9 is arranged to face a part of the second vertical protrusion 12 of the second ceiling portion 7b. On the other hand, the side surface 10b of the second widthwise protrusion 10 is arranged to face a part of the first vertical protrusion 11 of the first ceiling portion 7a.

[0039] 3 to 5, the vertical protrusions 11, 12 of the ceiling portions 7a, 7b have top surfaces 11a, 12a and side surfaces 11b, 12b. The side surface 11b of the first vertical protrusion 11 is arranged to contact the side surface 10b of the second widthwise protrusion 10. The side surface 12b of the second vertical protrusion 12 is arranged to contact the side surface 9b of the first widthwise protrusion 9.

[0040] Without being limited to the above configuration, in some of the multiple first ceiling portions 7a and second ceiling portions 7b arranged side by side, the side surfaces 11b, 12b of each vertical protrusion 11, 12 may be spaced apart from the side surfaces 9b, 10b of the corresponding widthwise protrusions 9, 10. This forms a gap between the spaced apart side surfaces (see FIG. 5).

[0041] With the above-described configuration, when the first ceiling portion 7 a and the second ceiling portion 7 b expand due to heating, the gap can absorb the expansion. Even when a gap is formed in this manner, the first contact surface 9 a of the first ceiling portion 7 a and the second contact surface 10 a of the second ceiling portion 7 b are in contact with each other, so that the ceiling portions 7 a and 7 b can airtightly close the upper portion of the feeder 3.

[0042] The electric heating elements 8a and 8b are made of, for example, molybdenum disilicide (MoSi ２ 2, the electric heating elements 8a and 8b are U-shaped members each having a bent portion 8c and two straight portions 8d arranged in parallel with each other via the bent portion 8c.

[0043] 2, the electric heating elements 8a and 8b are supported on the second ceiling portion 7b via fixing members 13. However, the electric heating elements 8a and 8b may be supported on the first ceiling portion 7a. The electric heating elements 8a and 8b include a first electric heating element 8a supported on one end of the second ceiling portion 7b and a second electric heating element 8b supported on the other end of the second ceiling portion 7b.

[0044] 2, 4, and 5, the second ceiling portion 7b has a pair of through holes 14a, 14b through which the electric heating elements 8a, 8b are inserted. Each of the through holes 14a, 14b passes through the second ceiling portion 7b in the vertical direction (thickness direction). As shown in Fig. 4, each of the through holes 14a, 14b is circular, but is not limited to this shape and may be rectangular or another shape.

[0045] The through holes 14a, 14b include a first through hole 14a formed at one end of the second ceiling portion 7b and a second through hole 14b formed at the other end of the second ceiling portion 7b. The first electric heating element 8a is inserted through the first through hole 14a, and the second electric heating element 8b is inserted through the second through hole 14b.

[0046] 2 and 5, the fixing member 13 is placed on top of the second ceiling portion 7b. The fixing member 13 supports parts of the electric heating elements 8a and 8b outside the feeder 3. The fixing member 13 has protrusions 13a that are inserted into the through holes 14a and 14b of the second ceiling portion 7b. The protrusions 13a function as guides for positioning the fixing member 13 relative to the through holes 14a and 14b of the second ceiling portion 7b.

[0047] To fix the electric heating elements 8a, 8b to the second ceiling portion 7b, the electric heating elements 8a, 8b inserted into the through holes 14a, 14b of the second ceiling portion 7b are attached to the fixing member 13, and then the protrusions 13a of the fixing member 13 are inserted into the through holes 14a, 14b of the second ceiling portion 7b. This positions the fixing member 13 with the through holes 14a, 14b of the second ceiling portion 7b, and fixes the electric heating elements 8a, 8b to the second ceiling portion 7b. The fixing member 13 also airtightly closes the through holes 14a, 14b from the outside of the second ceiling portion 7b.

[0048] 6 to 8 are cross-sectional views showing other examples of the ceiling portions 7a and 7b. In the example shown in Fig. 6, the first ceiling portion 7a and the second ceiling portion 7b are trapezoidal in cross-sectional view. The ceiling portion 7a has a first surface 7a1 and a second surface 7a2 facing in the vertical direction, and a third surface 7a3 and a fourth surface 7a4 formed between the first surface 7a1 and the second surface 7a2. Similarly, the ceiling portion 7b has a first surface 7b1 and a second surface 7b2 facing in the vertical direction, and a third surface 7b3 and a fourth surface 7b4 formed between the first surface 7b1 and the second surface 7b2.

[0049] The third surface 7a3 and the fourth surface 7a4 are inclined surfaces formed so as to form an obtuse angle with respect to the first surface 7a1 and an acute angle with respect to the second surface 7a2. Similarly, the third surface 7b3 and the fourth surface 7b4 are inclined surfaces formed so as to form an obtuse angle with respect to the first surface 7b1 and an acute angle with respect to the second surface 7b2. For example, the angle formed by the third surface 7a3 and the fourth surface 7a4 with respect to the second surface 7a2 (or the angle formed by the third surface 7b3 and the fourth surface 7b4 with respect to the second surface 7b2) (acute angle) is preferably 50° or more and 80° or less.

[0050] With the above configuration, the second surface 7a2, the third surface 7a3, and the fourth surface 7a4 of the first ceiling portion 7a form a first widthwise protrusion 9. Furthermore, the second surface 7b2, the third surface 7b3, and the fourth surface 7b4 of the second ceiling portion 7b form a second widthwise protrusion 10.

[0051] 6, when the second ceiling portion 7b is arranged upside down with respect to the first ceiling portion 7a, the first widthwise protrusion 9 of the first ceiling portion 7a and the second widthwise protrusion 10 of the second ceiling portion 7b overlap in the vertical direction. That is, in this example, the third surface 7a3 and the fourth surface 7a4 of the first ceiling portion 7a become the first contact surface 9a, and the third surface 7b3 and the fourth surface 7b4 of the second ceiling portion 7b become the second contact surface 10a that comes into contact with the first contact surface 9a.

[0052] In the example shown in Figure 7, each ceiling portion 7a, 7b is configured in a parallelogram shape in cross section. The first ceiling portion 7a and the second ceiling portion 7b have the same shape and dimensions. Each ceiling portion 7a, 7b has a first surface 7a1, 7b1 and a second surface 7a2, 7b2 facing in the vertical direction, and a third surface 7a3, 7b3 and a fourth surface 7a4, 7b4 formed between the first surface 7a1, 7b1 and the second surface 7a2, 7b2.

[0053] The third surfaces 7a3 and 7b3 are inclined surfaces formed so as to form an obtuse angle with the first surfaces 7a1 and 7b1 and an acute angle with the second surfaces 7a2 and 7b2. The fourth surfaces 7a4 and 7b4 are inclined surfaces formed so as to form an acute angle with the first surfaces 7a1 and 7b1 and an obtuse angle with the second surfaces 7a2 and 7b2. For example, the angles (acute angles) formed by the third surfaces 7a3 and 7b3 and the second surfaces 7a2 and 7b2 (or the angles (acute angles) formed by the fourth surfaces 7a4 and 7b4 and the first surfaces 7a1 and 7b1) are preferably between 50° and 80°.

[0054] The first surface 7a1 and the fourth surface 7a4 of the first ceiling portion 7a, and the second surface 7a2 and the third surface 7a3 form a first widthwise protrusion 9. The first surface 7b1 and the fourth surface 7b4 of the second ceiling portion 7b, and the second surface 7b2 and the third surface 7b3 form a second widthwise protrusion 10.

[0055] 7, the first widthwise protrusion 9 of the first ceiling portion 7a and the second widthwise protrusion 10 of the second ceiling portion 7b overlap in the vertical direction. That is, in this example, the third surface 7a3 and the fourth surface 7a4 of the first ceiling portion 7a serve as first contact surfaces 9a, and the third surface 7b3 and the fourth surface 7b4 of the second ceiling portion 7b serve as second contact surfaces 10a that come into contact with the first contact surfaces 9a.

[0056] 8, each of the ceiling portions 7a, 7b has a first surface 7a1, 7b1, a second surface 7a2, 7b2, a third surface 7a3, 7b3, and a fourth surface 7a4, 7b4. In this example, the first surfaces 7a1, 7b1 and the second surfaces 7a2, 7b2 are flat, while the third surfaces 7a3, 7b3 and the fourth surfaces 7a4, 7b4 are curved.

[0057] The third surfaces 7a3, 7b3 and the fourth surfaces 7a4, 7b4 have recesses 15 having concave curved surfaces and protrusions 16 having convex curved surfaces. The curved surfaces of the recesses 15 and the protrusions 16 are arc-shaped in cross section, but the shape of each curved surface is not limited to this embodiment. The recesses 15 and the protrusions 16 are formed adjacent to each other in the vertical direction. One end of the curved surface of the recesses 15 and one end of the curved surface of the protrusions 16 are continuously connected.

[0058] In this example, the convex portions 16 formed on the third surface 7a3 and the fourth surface 7a4 of the first ceiling portion 7a serve as the first width direction protrusions 9, and the convex portions 16 formed on the third surface 7b3 and the fourth surface 7b4 of the second ceiling portion 7b serve as the second width direction protrusions 10. Furthermore, a portion of the convex portion 16 on the first ceiling portion 7a serves as the first contact surface 9a, and a portion of the convex portion 16 on the second ceiling portion 7b serves as the second contact surface 10a.

[0059] In this example, the convex portion 16 of the first ceiling portion 7a enters the concave portion 15 of the second ceiling portion 7b, and the convex portion 16 of the second ceiling portion 7b enters the concave portion 15 of the first ceiling portion 7a, so that the first widthwise protrusion 9 of the first ceiling portion 7a is positioned so as to overlap in the vertical direction with the second widthwise protrusion 10 of the second ceiling portion 7b.

[0060] Hereinafter, a method for producing glass fiber Gf using the above-configured production apparatus 1 will be described. This method includes a melting step, a supplying step, and a molding step.

[0061] In the melting step, glass raw material Gr is melted in a melting furnace 2 to form molten glass Gm. In the supplying step, the molten glass Gm is caused to flow inside a feeder 3 and is supplied to a bushing 4 provided below the feeder 3. In the forming step, the molten glass Gm is caused to flow down from a bushing nozzle provided in the bushing 4 to form glass fibers Gf.

[0062] According to the feeder 3 of this embodiment described above, the first widthwise protrusion 9 of the first ceiling portion 7a and the second widthwise protrusion 10 of the second ceiling portion 7b can be stacked in the vertical direction, thereby integrating the first ceiling portion 7a and the second ceiling portion 7b.

[0063] In this way, by integrating the first ceiling portion 7a and the second ceiling portion 7b, the second moment of area can be increased, making it possible to suppress creep deformation of each ceiling portion 7a, 7b.

[0064] FIG. 9 is a cross-sectional view illustrating creep deformation in a conventional ceiling section. As shown in FIG. 9, a conventional ceiling section 7A has a rectangular cross section, and adjacent ceiling sections 7A only contact each other at their end surfaces 7A1 in the width direction W. In other words, the contact surfaces of adjacent ceiling sections 7A are perpendicular, and they exert almost no force on each other. Therefore, adjacent ceiling sections 7A are not integrated but exist independently. In this case, the cross-sectional area of ​​each ceiling section 7A is small, resulting in a small moment of inertia, making them prone to creep deformation in the longitudinal direction. Furthermore, because adjacent ceiling sections 7A are independent and not integrated, creep deformation is likely to occur in the middle portion of each ceiling section 7A in the width direction W, as shown in FIG. 9. When the ceiling section 7A deforms in this way, the end surfaces 7A1 of multiple ceiling sections 7A arranged side by side will separate from each other. This condition promotes creep deformation in the longitudinal direction of each ceiling section 7A.

[0065] In contrast, in the feeder 3 according to this embodiment, the first widthwise protrusion 9 (first contact surface 9a) of the first ceiling portion 7a and the second widthwise protrusion 10 (second contact surface 10a) of the second ceiling portion 7b are arranged so as to overlap one another. In other words, the contact surfaces between the first ceiling portion 7a and the second ceiling portion 7b include non-perpendicular surfaces. This allows the first ceiling portion 7a and the second ceiling portion 7b to exert forces on each other and become integrated. Specifically, the first ceiling portion 7a receives the load of the second ceiling portion 7b, and conversely, the second ceiling portion 7b applies a load to the first ceiling portion 7a. This increases the moment of inertia of the integrated ceiling portion 7, thereby suppressing creep deformation of the first ceiling portion 7a and the second ceiling portion 7b. Furthermore, by integrating the ceiling portions 7a and 7b, creep deformation in the middle of each ceiling portion 7a and 7b in the width direction W can be suppressed. This also effectively suppresses creep deformation in the longitudinal direction of each ceiling portion 7a and 7b in this embodiment.

[0066] In particular, the embodiments shown in Figures 3 to 5 and the embodiment shown in Figure 6 are preferable compared to the embodiments shown in Figures 7 and 8 in that they facilitate periodic repairs of the ceiling portion 7. For example, if a defect such as creep deformation or damage occurs in the second ceiling portion 7b, only the second ceiling portion 7b can be pulled upward and replaced. Also, if a defect occurs in the first ceiling portion 7a, the first ceiling portion 7a can be pulled out by pulling out the adjacent second ceiling portion 7b. In this way, periodic repairs can be performed on the ceiling portion 7 by moving only the defective component and its surrounding components.

[0067] The present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. The present invention can be modified in various ways without departing from the spirit of the present invention.

[0068] In the above embodiment, the feeder 3 used to manufacture glass fiber Gf is illustrated, but the present invention is not limited to this configuration. The present invention can also be applied to the manufacture of various glass products, such as glass plates and glass tubes.

[0069] In the above embodiment, the electric heating elements 8a and 8b are used as an example of the heating device for the molten glass Gm in the feeder 3, but the present invention is not limited to this configuration. A gas burner or other device may also be used as the heating device.

[0070] 3 Feeder 6a First side wall portion 6b Second side wall portion 7 Ceiling portion 7a First ceiling portion 7b Second ceiling portion 8a First electric heating element 8b Second electric heating element 9 First width direction protrusion 9a First contact surface 10 Second width direction protrusion 10a Second contact surface 13 Fixing member 14a First through hole 14b Second through hole Gm Molten glass

Claims

1. A feeder for circulating molten glass therethrough, comprising: a ceiling portion; and a side wall portion supporting the ceiling portion, wherein the side wall portion includes a first side wall portion and a second side wall portion arranged at a predetermined interval, the ceiling portion being constituted by a long fireproof member spanning the first side wall portion and the second side wall portion, the ceiling portion including a first ceiling portion and a second ceiling portion arranged adjacent to each other, the first ceiling portion having a first protrusion portion, and the second ceiling portion having a second protrusion portion, the first protrusion portion and the second protrusion portion overlap in the vertical direction.

2. A feeder as described in claim 1, wherein the first protrusion has a first contact surface that faces the second protrusion in the vertical direction, and the second protrusion has a second contact surface that contacts and overlaps the first contact surface in the vertical direction.

3. A feeder as claimed in claim 1 or 2, further comprising an electric heating element supported on said ceiling for heating said molten glass.

4. A feeder as claimed in claim 3, wherein said ceiling portion has a through hole through which said electric heating element is inserted.

5. The feeder according to claim 4, further comprising a fixing member for fixing said electric heating element inserted into said through hole to said ceiling portion.

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