Melting apparatus and method for producing glass article

Abstract

To suppress the volatilization of a glass component from molten glass on the downstream side of a melting furnace for melting glass raw materials.SOLUTION: A melting apparatus, comprises : a melting furnace that heats glass raw materials to produce molten glass; and a treatment furnace that heats the molten glass supplied from the melting furnace. The treatment furnace includes a ceiling wall composed of a plurality of refractory bricks, side walls composed of a plurality of refractory bricks, and seal layers provided on the ceiling wall and / or the side walls and sealing joints of the plurality of refractory bricks.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a melting apparatus for producing molten glass and a method for manufacturing a glass article.

Background Art

[0002] As is well known, glass articles typified by glass plates and glass tubes are manufactured by forming molten glass, which is produced by melting glass raw materials in a glass melting furnace, into a predetermined shape.

[0003] For example, the melting furnace disclosed in Patent Document 1 includes a melting chamber capable of containing molten glass and heating means for heating the glass raw materials introduced into the melting chamber. The melting chamber is made of a refractory, and the cross-sectional shape of the melting chamber is formed to be rectangular in plan view. The heating means includes a plurality of electrodes provided at the bottom of the melting chamber (see paragraphs 0025, 0026, 0030 and FIG. 1 of the same document).

[0004] The melting furnace is configured to heat and sequentially melt the glass raw materials continuously supplied onto the surface of the molten glass in the melting chamber by the heating means, and to let the molten glass flow out of the melting chamber (see paragraph 0025 of the same document).

[0005] The surface of the molten glass generated in the melting chamber is covered with the glass raw materials (see paragraphs 0009 and FIG. 2 of the same document). Thereby, excessive volatilization of the components of the molten glass can be prevented, and the quality of the glass article can be improved (see paragraph 0010 of the same document).

[0006] After being discharged from the melting chamber, the molten glass undergoes various treatments. For example, Patent Document 2 discloses a manufacturing apparatus for a glass article, which includes a melting furnace including a first melting tank and a second melting tank, a clarification tank provided downstream of the melting furnace and performing a defoaming treatment on the molten glass, and a forming apparatus for forming the molten glass (see paragraphs 0019, 0020 and FIG. 1 of the same document). The clarification tank in this manufacturing apparatus is made of a refractory in the same manner as the melting furnace (see paragraph 0027 of the same document).

[0007] The manufacturing method of glass articles using this manufacturing apparatus includes a melting step of heating glass raw materials in a melting furnace to produce molten glass, a fining step of performing defoaming treatment on the molten glass produced in the melting step using a fining tank, and a forming step of forming the molten glass after the fining step using a forming apparatus (see paragraph 0032 of the same document).

[0008] In the melting step, the glass raw materials charged into the first melting tank are heated by a heating device provided in the first melting tank. Thereby, molten glass is produced in the first melting tank. Next, the molten glass flows into the second melting tank and is maintained at a constant temperature. In the fining step, the molten glass flowing from the second melting tank into the fining tank is heated and defoaming treatment is performed (see paragraphs 0033 and 0034 of the same document).

[0009] In the subsequent forming step, the molten glass is transferred from the fining tank to the forming apparatus and formed into a predetermined shape by this forming apparatus (see paragraph 0035 of the same document).

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0011] In the conventional manufacturing method of glass articles as described above, the surface of the molten glass produced in the melting step is covered with the glass raw materials sequentially charged into the melting furnace. Thereby, excessive volatilization of the components of the molten glass can be suppressed.

[0012] However, as disclosed in Patent Document 2, in the second melting tank and the clarification tank located downstream of the first melting tank in the melting furnace, the surface of the molten glass is exposed without being covered by the glass raw material, so it is difficult to suppress the volatilization of the components of the molten glass. For this reason, excessive volatilization of the components of the molten glass occurs, generating heterogeneous glass called scum on the surface of the molten glass, which may cause defects such as veining in glass articles manufactured from the molten glass.

[0013] The present invention has been made in view of the above circumstances, and its technical problem is to suppress the volatilization of glass components from molten glass on the downstream side of a melting furnace that melts glass raw materials.

Means for Solving the Problems

[0014] (1) The present invention is for solving the above problems, and is a melting apparatus including a melting furnace that heats glass raw materials to generate molten glass, and a processing furnace that heats the molten glass supplied from the melting furnace, wherein the processing furnace includes a ceiling wall composed of a plurality of refractory bricks, a side wall composed of a plurality of refractory bricks, and a seal layer provided at an upper part of the ceiling wall and / or the side wall for sealing joints of the plurality of refractory bricks.

[0015] In a processing furnace composed of refractory bricks, there is a risk that glass components volatilized from the molten glass leak out of the processing furnace through the joints of the refractory bricks. In this method, by sealing the joints of the refractory bricks with a seal layer provided at the upper part of the ceiling wall and / or the side wall, it is possible to prevent the glass components from leaking out of the processing furnace. Thereby, in the internal space of the processing furnace, the glass components volatilized from the molten glass can be maintained in a saturated state. Thereby, it becomes possible to effectively suppress the volatilization of glass components from the molten glass.

[0016] (2) In the melting apparatus according to (1) above, the seal layer includes a first seal layer that seals the joints related to the plurality of refractory bricks constituting the ceiling wall, and a second seal layer that seals the joints related to the plurality of refractory bricks constituting the side wall. The first seal layer may be provided on the back side of the ceiling wall, and the second seal layer may be provided on the back side of the upper portion of the side wall.

[0017] According to such a configuration, by sealing both the back side of the ceiling wall and the back side of the upper portion of the side wall with the first seal layer and the second seal layer, the volatilization of glass components from the molten glass can be more effectively suppressed.

[0018] (3) In the melting apparatus according to (1) or (2) above, the seal layer may be composed of amorphous refractories.

[0019] According to such a configuration, a seal layer without gaps can be formed, and it is possible to more reliably prevent glass components from leaking to the outside of the processing furnace. Therefore, it is possible to further suppress the volatilization of glass components from the molten glass.

[0020] (4) In the melting apparatus according to any one of (1) to (3) above, the processing furnace may be a fining tank.

[0021] Since the molten glass in the fining tank is not covered with glass raw materials, scum is likely to occur. Therefore, if the present invention is applied to the fining tank, the effect of effectively suppressing the volatilization of glass components from the molten glass becomes more remarkable.

[0022] (5) The present invention is for solving the above problems, and is a method for manufacturing a glass article comprising a melting step of heating a glass raw material by a melting furnace to produce molten glass, and a treatment step of heating the molten glass supplied from the melting furnace by a treatment furnace, wherein the treatment furnace comprises a ceiling wall composed of a plurality of refractory bricks, a side wall composed of a plurality of refractory bricks, and a seal layer provided at an upper portion of the ceiling wall and / or the side wall for sealing joints between the plurality of refractory bricks.

[0023] According to such a configuration, by sealing the joints between the refractory bricks with the seal layer provided at the upper portion of the ceiling wall and / or the side wall of the treatment furnace, it is possible to prevent the glass components volatilized from the molten glass from leaking to the outside of the treatment furnace. Therefore, in the internal space of the treatment furnace, the glass components volatilized from the molten glass can be maintained in a saturated state. Thereby, it becomes possible to effectively suppress the volatilization of the glass components from the molten glass.

[0024] (6) In the method for manufacturing a glass article according to (5) above, the molten glass may be an alkali-containing glass, a borosilicate glass, or a lead glass.

[0025] In the case of alkali-containing glass, alkali metal elements are likely to volatilize from the molten glass. In the case of borosilicate glass, boron is likely to volatilize from the molten glass. In the case of lead glass, lead is likely to volatilize from the molten glass. If the present invention is applied to these glasses, the effect of effectively suppressing the volatilization of the glass components from the molten glass becomes more remarkable.

Effects of the Invention

[0026] According to the present invention, it is possible to suppress the volatilization of the glass components from the molten glass on the downstream side of the melting furnace that melts the glass raw material.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0028] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIGS. 1 to 3 show an embodiment of a method for manufacturing a glass article and a melting apparatus according to the present invention.

[0029] FIG. 1 shows a manufacturing apparatus for a glass article used in this method. The manufacturing apparatus 1 mainly includes a melting apparatus 2 that generates molten glass GM, a transfer channel 3 that transfers the molten glass GM, and a forming apparatus 4 that forms the molten glass GM.

[0030] The melting apparatus 2 includes a melting furnace 5 that heats a glass raw material F to generate molten glass GM, and a fining tank 6 as a treatment furnace that heats the molten glass GM supplied from the melting furnace 5.

[0031] As shown in FIG. 2, the melting furnace 5 includes a bottom wall 7, side walls 8a, 8b, and a ceiling wall 9. The melting furnace 5 defines an internal space for accommodating the molten glass GM by the bottom wall 7, the side walls 8a, 8b, and the ceiling wall 9.

[0032] The bottom wall 7 includes a plurality of refractory bricks made of refractory materials. The bottom wall 7 is configured by stacking the refractory bricks vertically in a plurality of layers. The refractory bricks are made of refractory materials such as, for example, AZS electrocast bricks, high zirconia electrocast bricks, dense zircon fired bricks, chrome bricks, or by combining these refractory materials.

[0033] The melting furnace 5 has a plurality of electrodes 10 that project upward from the bottom wall 7. The electrodes 10 are configured in a rod shape, but may be configured in a plate shape or a block shape. The electrodes 10 are made of, for example, molybdenum, but are not limited to this configuration. The melting furnace 5 may have electrodes provided on the side walls 8a, 8b.

[0034] In this embodiment, combustion heating means such as a burner for melting the glass raw material F is not provided in the space above the surface (liquid level) of the molten glass GM in the melting furnace 5. This embodiment exemplifies a melting furnace 5 of a so-called all-electric melting method in which the glass raw material F is melted only by energization heating with electrodes.

[0035] If such an all-electric melting type melting furnace 5 is adopted, since combustion heating means such as a burner is not used, the ambient temperature in the melting furnace 5 can be significantly reduced. In addition, in the startup process before starting the melting process (the process of raising the temperature of the melting furnace 5 from room temperature to a temperature at which the glass raw material F can be melted), a burner may be used.

[0036] The side walls 8a and 8b are composed of a plurality of refractory bricks made of refractory materials. As the refractory bricks, fired bricks such as chrome bricks are used, for example.

[0037] As shown in FIG. 2, the side walls 8a and 8b include a first side wall 8a as a front wall located on the upstream side, a second side wall 8b as a rear wall located on the downstream side, and a third side wall (not shown) and a fourth side wall (not shown) connecting the first side wall 8a and the second side wall 8b.

[0038] A raw material supply unit 11 for supplying the glass raw material F to the melting furnace 5 is provided on the first side wall 8a of the melting furnace 5. The raw material supply unit 11 supplies the glass raw material F by a supply device 12 composed of a screw feeder through an opening formed in the first side wall 8a. The supply device 12 is not limited to a screw feeder, and various other feeders may be used.

[0039] An outlet 13 for discharging the molten glass GM is provided on the second side wall 8b of the melting furnace 5. The outlet 13 is connected to the clarification tank 6 through a connection part 14. Thereby, the melting furnace 5 is configured such that the molten glass GM flows from the first side wall 8a side toward the second side wall 8b side.

[0040] The connecting part 14 that connects the melting furnace 5 and the clarification tank 6 constitutes a flow path for transferring the molten glass GM in the melting furnace 5 to the clarification tank 6. The connecting part 14 is formed in a hollow shape by refractory materials such as refractory bricks, platinum, platinum alloys, etc.

[0041] The clarification tank 6 is provided on the downstream side of the melting furnace 5. The clarification tank 6 is a treatment furnace that heats the molten glass GM and performs a defoaming treatment. As shown in FIGS. 2 and 3, the clarification tank 6 includes a bottom wall 15, side walls 16a to 16d, a ceiling wall 17, seal layers 18a and 18b that seal the ceiling wall 17 and side walls 16c and 16d, and heat insulating layers 19a and 19b that cover the ceiling wall 17 and side walls 16a to 16d. The clarification tank 6 defines an internal space for accommodating the molten glass GM by the bottom wall 15, side walls 16a to 16d, and ceiling wall 17.

[0042] The bottom wall 15 includes a plurality of refractory bricks (refractory blocks) 15a made of refractory materials. The bottom wall 15 is formed by stacking the refractory bricks 15a vertically in a plurality of layers. The refractory bricks 15a are made of, for example, high zirconia electroformed refractory bricks, dense zircon fired bricks, chrome bricks, or other refractory materials, or by combining these refractory materials.

[0043] The clarification tank 6 has a plurality of electrodes 20 that project upward from the bottom wall 15. The electrodes 20 are formed in a rod shape, but may also be formed in a plate shape or a block shape. The electrodes 20 are made of, for example, molybdenum, but are not limited to this configuration. The clarification tank 6 may also have electrodes provided on the side walls 16a to 16d.

[0044] As shown in FIGS. 2 and 3, the side walls 16a to 16d include a first side wall 16a as a front wall located on the upstream side, a second side wall 16b as a rear wall located on the downstream side, and third and fourth side walls 16c and 16d that connect the first side wall 16a and the second side wall 16b.

[0045] On the first side wall 16a of the clarification tank 6, a supply port 21 connected to the connection part 14 is provided. On the second side wall 16b of the clarification tank 6, a discharge port 22 for discharging the molten glass GM is provided. The discharge port 22 is connected to the transfer channel 3. Thus, the clarification tank 6 is configured such that the molten glass GM flows from the first side wall 16a side toward the second side wall 16b side.

[0046] As shown in FIG. 3, the third side wall 16c and the fourth side wall 16d have a lower structure 23 that contacts the molten glass GM, an upper structure 24 located above the lower structure 23, and a support part 25 that supports the ceiling wall 17.

[0047] The lower structure 23 includes a plurality of refractory bricks 23a made of refractory material. This refractory brick 23a is also called a side block. As the refractory brick 23a, for example, a fired brick such as a chrome brick is used, but the material of the refractory brick 23a is not limited to this embodiment.

[0048] In this embodiment, an example is shown in which the refractory brick 23a is composed of one long refractory block without being divided in the vertical direction, but it is not limited to this, and the lower structure 23 may be composed of a plurality of refractory blocks divided in the vertical direction.

[0049] In the present embodiment, the upper part of the upper structure 24 supports the support part 25, but the support part 25 may be clamped by a frame structure (not shown). In the present embodiment, the lower part of the upper structure 24 is supported by the lower structure 23, but it may be supported by a frame structure (not shown) via a tax stone. Here, the frame structure includes, for example, a plurality of columns made of shaped steel and fittings provided on the columns for supporting the refractory bricks.

[0050] The upper structure 24 has a plurality of refractory bricks (refractory blocks) 24a made of refractory material. The plurality of refractory bricks 24a are stacked in the vertical direction. Thereby, a joint 24b is formed at the contact part of each refractory brick 24a.

[0051] A part of the upper structure 24 on the third side wall 16c is provided with an exhaust passage 26 for discharging the gas in the clarification tank 6. The exhaust passage 26 is configured to be openable and closable, and can discharge the gas in the clarification tank 6 to the outside of the clarification tank 6 as necessary.

[0052] The support portion 25 is composed of a plurality of refractory bricks (refractory blocks) made of refractory materials. The support portion 25 has a support surface 25a that supports the ceiling wall 17. The support surface 25a is a surface (inclined surface) that is inclined at a predetermined angle with respect to the vertical direction.

[0053] As shown in FIG. 3, the ceiling wall 17 is configured in an arch shape by stacking a plurality of refractory bricks (refractory blocks) 17a. Thereby, joints 17b are formed at the contact portions of the respective refractory bricks 17a. The end portions in the width direction W of the ceiling wall 17 are supported by the support surfaces 25a of the support portions 25 on the third side wall 16c and the fourth side wall 16d.

[0054] The seal layers 18a and 18b include a first seal layer 18a and a second seal layer 18b. The first seal layer 18a is provided on the back surface 17c side (upper surface side) of the ceiling wall 17 and seals the joints 17b of the plurality of refractory bricks 17a of the ceiling wall 17. The second seal layer 18b is provided on the back surface 24c side of the upper structures 24 of the third side wall 16c and the fourth side wall 16d and seals the joints 24b of the plurality of refractory bricks 24a.

[0055] Each of the seal layers 18a and 18b is composed of an amorphous refractory material such as mortar, castable, ramming, or stamp. Specifically, each of the seal layers 18a and 18b is preferably composed of alumina cement, zirconia cement, silica cement, or the like.

[0056] A spacer 27 is interposed between the first seal layer 18a and the back surface 17c of the ceiling wall 17. The spacer 27 is composed of a refractory brick (refractory block). The spacer 27 is for forming a flat surface on the back surface 17c side of the ceiling wall 17.

[0057] The first seal layer 18a includes a first portion 18a1 and a second portion 18a2. The first portion 18a1 covers the upper part of the spacer 27. The second portion 18a2 covers the side part of the spacer 27.

[0058] The first portion 18a1 has a constant thickness and is linearly configured along the width direction W of the clarification tank 6. The first portion 18a1 is configured as a single layer that covers the entire back surface 17c of the ceiling wall 17. Thereby, the first portion 18a1 covers all the joints 17b related to the ceiling wall 17. Not limited to this configuration, the first portion 18a1 may be composed of a plurality of portions that partially cover the joints 17b of the ceiling wall 17. The thickness of the first portion 18a1 is, for example, 10 mm or more and 200 mm or less.

[0059] The second portion 18a2 of the first seal layer 18a is connected to each end of the first portion 18a1 and is linearly configured along the vertical direction (up and down direction). The thickness of the second portion 18a2 is, for example, 30 mm or more and 250 mm or less.

[0060] The second seal layer 18b has a constant thickness and is linearly configured along the up and down direction. The thickness of the second seal layer 18b is, for example, 30 mm or more and 250 mm or less. The second seal layer 18b is provided inside the heat insulation layer 19b and covers the joint 24b at a position away from the back surface 24c of the upper structure 24. Not limited to this configuration, the second seal layer 18b may cover the joint 24b directly in contact with the back surface 24c of the upper structure 24.

[0061] The heat insulation layers 19a and 19b are formed by laminating a plurality of refractory bricks made of refractory materials. As shown in FIG. 3, the heat insulation layers 19a and 19b include a first heat insulation layer 19a that covers the ceiling wall 17 and a second heat insulation layer 19b that covers the third side wall 16c and the fourth side wall 16d. The first heat insulation layer 19a is provided outside the first seal layer 18a. The second heat insulation layer 19b is provided outside (upper side) of the third side wall 16c and the fourth side wall 16d.

[0062] The transfer channel 3 connects the discharge port 22 of the clarification tank 6 and the forming device 4. The transfer channel 3 is formed in a hollow shape by refractory materials such as refractory bricks, platinum, platinum alloys, etc. On the path of the transfer channel 3, if necessary, a stirring tank for stirring the molten glass GM by a stirrer or a state adjustment tank for adjusting the state (e.g., viscosity and flow rate) of the molten glass GM may be provided.

[0063] The forming device 4 forms glass articles from the molten glass GM supplied by the transfer channel 3. Examples of the glass articles manufactured by the forming device 4 include cover glass for displays, glass tubes for pharmaceuticals, or radiation shielding glass.

[0064] Hereinafter, a method for manufacturing glass articles by the manufacturing apparatus 1 having the above configuration will be described. This method mainly includes a melting step, a clarification step as a treatment step after the melting step, and a forming step.

[0065] In the melting step, the glass raw material F supplied into the melting furnace 5 from the raw material supply unit 11 is heated by the electrodes 10. As a result, the glass raw material F melts and the molten glass GM is generated. The molten glass GM flows into the supply port 21 of the clarification tank 6 through the discharge port 13 and the connection part 14 of the melting furnace 5.

[0066] In the clarification step, the molten glass GM is heated by the electrodes 20 of the clarification tank 6 to maintain the temperature of the molten glass GM constant. The glass raw material F is blended with a clarifying agent, and gas (bubbles) is generated in the molten glass GM heated in the clarification tank 6 due to the action of this clarifying agent. In the clarification step, while the molten glass GM flows from the supply port 21 toward the discharge port 22, the gas contained in the molten glass GM is removed. Thereafter, the molten glass GM flows into the transfer channel 3 from the discharge port 22 and is transferred to the forming device 4 through the transfer channel 3.

[0067] In the forming step, the molten glass GM supplied from the transfer channel 3 is formed into a predetermined shape by the forming device 4. After the forming step, various steps such as a slow cooling step, a cutting step, an inspection step, a cleaning step, etc. may be carried out.

[0068] As the molten glass GM, alkali-containing glass, borosilicate glass, lead glass, etc. are used. Examples of articles manufactured from alkali-containing glass include cover glass for displays (chemically strengthened glass). Examples of glass articles manufactured from borosilicate glass include glass tubes for pharmaceuticals. Examples of glass articles manufactured from lead glass include radiation shielding glass.

[0069] According to the manufacturing method of the glass article and the melting apparatus 2 according to the present embodiment described above, the first seal layer 18a provided on the back surface 17c side of the ceiling wall 17 of the fining tank 6 and the second seal layer 18b provided on the back surface 24c side of the upper structures 24 of the side walls 16c, 16d can seal the joints 17b, 24b of the refractory bricks 17a, 24a related to the ceiling wall 17 and the side walls 16c, 16d.

[0070] Thereby, it is possible to prevent the glass components (for example, alkali metal elements, boron, etc.) volatilized from the molten glass GM from leaking from the ceiling wall 17 of the fining tank 6 and the upper structures 24 of the side walls 16c, 16d. Therefore, it is possible to make the glass components volatilized in the internal space of the fining tank 6 in a saturated state, and it becomes possible to suppress further volatilization of the glass components from the molten glass GM.

[0071] In addition, by covering all the joints 17b related to the ceiling wall 17 with the first seal layer 18a, it is possible to more reliably seal the joints 17b as compared with the case of covering the joints 17b individually. That is, when the joints 17b are individually sealed, there is a possibility that a gap may occur between the refractory brick 17a and the first seal layer 18a due to thermal expansion or the like. However, if the first seal layer 18a that seals a plurality of joints 17b is used, it is difficult for a gap to occur, and the sealing performance can be improved. The same effect can be obtained when a plurality of joints 24b related to the refractory bricks 24a of the side walls 16c, 16d are sealed by the second seal layer 18b.

[0072] Note that 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 variously modified without departing from the gist of the present invention.

[0073] In the above embodiment, the clarification tank 6 is exemplified as the treatment furnace disposed on the downstream side of the melting furnace 5, but the present invention is not limited to this configuration. The treatment furnace may include, for example, a second melting furnace provided on the downstream side of the melting furnace 5. By heating the molten glass generated by the first melting furnace 5 with the second melting furnace, the temperature control of the molten glass GM can be easily performed.

[0074] In the above embodiment, the melting apparatus 2 including the first seal layer 18a for sealing the back surface 17c side of the ceiling wall 17 related to the clarification tank 6 and the second seal layer 18b for sealing the back surface 24c side of the upper portions (upper structures 24) of the side walls 16c and 16d related to the clarification tank 6 is exemplified, but the present invention is not limited to this configuration. The seal layer may be provided only on the back surface 17c side of the ceiling wall 17 of the clarification tank 6. Further, the seal layer may be provided only on the back surface 24c side of the upper structures 24 in the side walls 16c and 16d of the clarification tank 6.

Explanation of Reference Numerals

[0075] 2 Melting apparatus 5 Melting furnace 6 Clarification tank (treatment furnace) 16c Third side wall of clarification tank 16d Fourth side wall of clarification tank 17 Ceiling wall of clarification tank 17b Joint of ceiling wall 18a First seal layer 18b Second seal layer 24 Upper structure of side wall 24b Joint in upper structure of side wall F Glass raw material GM Molten glass

Claims

1. A melting apparatus comprising a melting furnace that heats glass raw materials to produce molten glass, and a treatment furnace that heats the molten glass supplied from the melting furnace, wherein the treatment furnace includes a ceiling wall composed of a plurality of refractory bricks, a side wall composed of a plurality of refractory bricks, and a seal layer provided at an upper portion of the ceiling wall and / or the side wall to seal joints between the plurality of refractory bricks. The melting apparatus is characterized by this.

2. The seal layer includes a first seal layer that seals joints related to the plurality of refractory bricks constituting the ceiling wall, and a second seal layer that seals joints related to the plurality of refractory bricks constituting the side wall, wherein the first seal layer is provided on the back side of the ceiling wall, and the second seal layer is provided on the back side of the upper portion of the side wall. The melting apparatus according to Claim 1.

3. The seal layer is composed of refractory castables. The melting apparatus according to Claim 1 or 2.

4. The treatment furnace is a fining tank. The melting apparatus according to Claim 1 or 2.

5. A method for manufacturing a glass article, comprising a melting step of heating glass raw materials by a melting furnace to produce molten glass, and a treatment step of heating the molten glass supplied from the melting furnace by a treatment furnace, wherein the treatment furnace includes a ceiling wall composed of a plurality of refractory bricks, a side wall composed of a plurality of refractory bricks, and a seal layer provided at an upper portion of the ceiling wall and / or the side wall to seal joints between the plurality of refractory bricks. The method for manufacturing a glass article is characterized by this.

6. The molten glass is alkali-containing glass, borosilicate glass, or lead glass. The method for manufacturing a glass article according to Claim 5.

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