Method for manufacturing glass article

Abstract

The present invention provides a method for manufacturing a glass article capable of accurately managing the temperature of an annealing furnace. A method for manufacturing a glass article includes an annealing step (S2) in which a glass ribbon (GR) is annealed in an annealing furnace (3). An annealing furnace (3) is provided with: wall members (13a, 13b) that face a glass ribbon (GR); a heater (16) that heats the wall members (13a-13d); and a cooler (18) that cools the wall members (13a, 13b). In the annealing step (S2), the wall members (13a, 13b) are cooled by a cooler (18) while being heated by a heater (16).

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a glass article. Background Art

[0002] As is well known, glass plates are used as glass substrates and cover glasses in displays such as liquid crystal displays and organic EL displays. Down-draw methods are widely used as a method for manufacturing glass plates. Examples of down-draw methods include overflow down-draw methods and slit down-draw methods.

[0003] The overflow down-draw method involves flowing molten glass into an overflow trough located at the top of a forming body with a roughly wedge-shaped cross-section. The molten glass overflowing from the overflow trough flows down along the sidewalls of the forming body and fuses at its lower end, forming a continuous glass ribbon. The slot down-draw method involves forming a slit-shaped opening in the bottom wall of the forming body, into which the molten glass is fed, and allowing the molten glass to flow down through this opening, forming a continuous glass ribbon.

[0004] For example, Patent Document 1 discloses a method for producing a glass sheet using the overflow down-draw method. This method utilizes a forming furnace (forming zone) in which a glass ribbon is formed from molten glass using a forming body; an annealing furnace (annealing zone) in which the glass ribbon descending from the forming furnace is guided downward while annealing; and a cooling chamber (cooling zone) in which the glass ribbon passing through the annealing furnace is cooled while being pulled downward by support rollers. The glass ribbon passing through the cooling chamber is then obtained as a ribbon-shaped glass sheet (glass film) (see Claim 1 of this document).

[0005] In the annealing furnace, heating is performed using multiple heating devices to set a predetermined temperature gradient in the vertical direction (see paragraph 0034 of the document). As a result, the glass ribbon passing through the annealing furnace is gradually cooled to suppress strain.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-91351 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] In order to produce a high-quality glass ribbon with suppressed strain in an annealing furnace, it is necessary to accurately manage the temperature gradient in the annealing furnace. Therefore, it is necessary to accurately control the heating temperature of the heating device arranged in the annealing furnace.

[0011] The present invention has been made in view of the above circumstances, and a technical object of the present invention is to perform temperature management of an annealing furnace with high accuracy.

[0012] Solutions to Problems

[0013] (1) The present invention is a method for manufacturing a glass article for solving the above-mentioned problems, comprising an annealing step of annealing a glass ribbon in an annealing furnace, wherein the annealing furnace comprises: a wall member facing the glass ribbon; and a heating unit for adjusting the temperature of the wall member, wherein the heating unit comprises: a heater for heating the wall member; and a cooler for cooling the wall member, and in the annealing step, the wall member is cooled by the cooler while being heated by the heater.

[0014] According to this structure, the wall member is heated by the heater and cooled by the cooler at the same time, thereby improving responsiveness and accurately adjusting the heating temperature of the wall member. As a result, high-quality glass products with suppressed strain can be stably manufactured.

[0015] (2) In the method for manufacturing a glass article described in (1) above, the cooler may include a cooling nozzle for blowing gas toward the wall member.

[0016] According to this structure, by blowing gas from the cooling nozzle toward the wall member, the wall member can be uniformly cooled, and the temperature in the annealing process can be accurately managed, thereby improving the quality of the glass ribbon. In addition, compared with the case where a liquid such as water is used as the cooling medium, there is no need for equipment for recovering the refrigerant, thereby reducing equipment costs and simplifying the device structure.

[0017] (3) In the method for manufacturing a glass article according to (2) above, the cooling nozzle may be configured to be flat. This configuration allows the wall member to be uniformly cooled.

[0018] (4) In the method for manufacturing a glass article described in (2) or (3) above, the heating unit may include a thermometer for measuring the temperature of the wall member, and in the annealing step, the temperature of the wall member is measured using the thermometer disposed at one of the upper and lower portions of the heating unit, and the gas is blown toward the wall member using the cooling nozzle disposed at the other of the upper and lower portions of the heating unit.

[0019] According to this configuration, the thermometer and the cooling nozzle are arranged at positions separated in the vertical direction, so that the thermometer can accurately and stably measure the temperature of the wall member without being affected by the gas supplied from the cooling nozzle.

[0020] (5) In the method for manufacturing a glass article according to any one of (1) to (4), in the annealing step, the wall member may be set to a temperature of 500° C. to 900° C. This allows efficient annealing of the glass ribbon.

[0021] (6) In the method for manufacturing a glass article described in (2) or (3), the annealing furnace may include a holding brick for holding the heater, and the holding brick may have an exhaust port for exhausting the gas.

[0022] According to this configuration, the gas supplied from the cooler is discharged from the exhaust port, whereby the heating temperature of the wall member can be adjusted with high accuracy.

[0023] Effects of the Invention

[0024] According to the present invention, the temperature of the annealing furnace can be managed with high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a side view showing a manufacturing apparatus for a glass article.

[0026] Figure 2 This is a front view showing a glass article manufacturing apparatus.

[0027] Figure 3 It is a partial side sectional view of the annealing furnace.

[0028] Figure 4 It is a partial front cross-sectional view of the annealing furnace.

[0029] Figure 5 is a flowchart illustrating a method for manufacturing a glass article.

[0030] Description of Reference Numerals

[0031] 3 Annealing furnace

[0032] 13a First wall member

[0033] 13b Second wall member

[0034] 13c Third wall member

[0035] 13d Fourth wall component

[0036] 16 Heater

[0037] 17a First retaining brick

[0038] 17b Second retaining brick

[0039] 18 Cooler

[0040] 18a Cooling nozzle

[0041] 19 Thermometer

[0042] 24a Exhaust port

[0043] A Cooling air (gas)

[0044] G Glass Pane (Glass Item)

[0045] GR Glass Ribbon (Glass Items)

[0046] S2 annealing process. DETAILED DESCRIPTION

[0047] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figures 1 to 5 An embodiment of a method for manufacturing a glass article according to the present invention is shown. It should be noted that in the orthogonal coordinate system consisting of X, Y, and Z shown in the figure, the X and Y directions are horizontal directions, and the Z direction is the vertical direction. Furthermore, the direction corresponding to the width of the formed glass ribbon is referred to as the width direction X, and the direction corresponding to the thickness of the formed glass ribbon is referred to as the thickness direction Y.

[0048] Figure 1 as well as Figure 2 A manufacturing apparatus for glass articles for implementing the present method is shown. The manufacturing apparatus 1 includes a forming furnace 2; an annealing furnace 3 located below the forming furnace 2; a cooling chamber 4 located below the annealing furnace 3; and a cutting chamber 5 located below the cooling chamber 4. The forming furnace 2 and annealing furnace 3, the annealing furnace 3 and cooling chamber 4, and the cooling chamber 4 and cutting chamber 5 are partitioned by partition members (e.g., building floors) F1, F2, and F3, respectively, each having an opening (e.g., a slit) through which the glass ribbon GR passes.

[0049] like Figure 1 as well as Figure 2 As shown, the forming furnace 2 is an area for forming a glass ribbon GR from molten glass GM by an overflow downdraw method. The forming furnace 2 includes a forming body 6 for forming the glass ribbon GR from the molten glass GM and first conveying rollers 7 for cooling both ends of the glass ribbon GR formed by the forming body 6 in the width direction X.

[0050] The formed body 6 is formed of a refractory material that is elongated along the width direction X. Examples of the refractory material include zircon, zirconia, alumina, magnesia, and xenotime.

[0051] The forming body 6 has a groove portion (overflow groove) 8 formed on its upper portion along the width direction X. Molten glass GM is supplied into the groove portion 8 through a supply pipe 9. The supply method of molten glass GM is not limited to this. For example, molten glass GM may be supplied from both sides of the groove portion 8 in the width direction X, or from above the groove portion 8.

[0052] The molded body 6 has a symmetrical shape in the thickness direction Y. The two outer side surfaces 10 of the molded body 6 in the thickness direction Y each include a vertical surface 11 that is a flat surface extending along the vertical direction, and an inclined surface 12 that is continuous with the bottom of the vertical surface 11 and is a flat surface inclined relative to the vertical direction.

[0053] Each vertical surface portion 11 is a parallel plane. Each inclined surface portion 12 is a plane inclined so as to approach each other as it approaches downward in the thickness direction Y. Specifically, the formation of each inclined surface portion 12 gives the molded body 6 a wedge shape that tapers downward when viewed in the width direction X. The corner where each inclined surface portion 12 intersects forms the lower end portion 6a of the molded body 6. It should be noted that the vertical surface portions 11 may be modified to have an inclined surface, a curved surface, or the like, or may be omitted.

[0054] like Figure 1 as well as Figure 2 As shown, the first conveying rollers 7 are configured as a pair of rollers that sandwich the ends of the glass ribbon GR in the width direction X in the thickness direction Y directly below the forming body 6. The first conveying rollers 7 are cantilever-type rollers with internal cooling mechanisms. The first conveying rollers 7 are also called cooling rollers or edge rollers.

[0055] The annealing furnace 3 is an area for suppressing the warping and internal strain of the glass ribbon GR. Figures 1 to 4 As shown, the annealing furnace 3 includes wall members 13a to 13d constituting a furnace wall, a heating unit 14 for heating the wall members 13a to 13d, and second conveying rollers 15 for conveying the glass ribbon GR.

[0056] The wall members 13a to 13d are used to partition the internal space of the annealing furnace 3. The wall members 13a to 13d are made of, for example, refractory bricks. Figure 1 as well as Figure 2 As shown, the wall members 13a to 13d include: a first wall member 13a, which is opposite to the main surface GRa of one side of the glass ribbon GR; a second wall member 13b, which is opposite to the main surface GRb of the other side of the glass ribbon GR; and a third wall member 13c and a fourth wall member 13d, which connect the first wall member 13a and the second wall member 13b.

[0057] like Figure 1 As shown, the first wall member 13a and the second wall member 13b are opposed to each other in the thickness direction Y. Figure 2As shown in FIG, the third wall member 13c and the fourth wall member 13d are opposed to each other in the width direction X.

[0058] like Figure 1 as well as Figure 2 As shown, the heating units 14 include a plurality of units configured to cover the outside of the wall member 13a or 13b facing the main surfaces GRa, GRb of the glass ribbon GR. Specifically, the plurality of heating units 14 are arranged along the width direction X and the vertical direction Z so as to cover the outside of the wall member 13a or 13b. The temperature of the wall member 13a or 13b heated by the multiple stages of heating units 14 arranged along the vertical direction Z varies, thereby forming a temperature gradient within the annealing furnace 3. Specifically, the heating temperature of the plurality of heating units 14 is set so as to decrease as the temperature approaches the bottom.

[0059] like Figure 3 as well as Figure 4 As shown, the heating unit 14 includes: a heater 16 that heats the wall member 13a or 13b; holding bricks 17a, 17b that hold the heater 16; a cooler 18 that cools the wall member 13a or 13b; a thermometer 19 that measures the temperature of the wall member 13a or 13b; and a partition member 20.

[0060] Figure 3 The structure of the heating unit 14 corresponding to the first wall member 13a is shown, but the heating unit 14 also has the same structure in relation to the other wall member 13b. Figure 4 Show Figure 3 Cross-sectional view of the IV-IV direction.

[0061] The heater 16 is composed of, for example, a SiC heating device, but is not limited thereto, and other heating devices may also be used. Figure 3 as well as Figure 4 As shown, the heater 16 includes a main body portion 16 a and support portions 16 b and 16 c that support the main body portion 16 a.

[0062] The main body portion 16a is configured as an elongated portion along the up-down direction Z. The main body portion 16a is disposed in the accommodation space S formed between the holding bricks 17a and 17b and the wall member 13a or 13b.

[0063] Supporting portions 16b and 16c are horizontally elongated strips. They consist of a first supporting portion 16b connected to the upper portion of the main body 16a and a second supporting portion 16c connected to the lower portion of the main body 16a. Each supporting portion 16b and 16c extends through retaining bricks 17a and 17b. The front end of each supporting portion 16b and 16c is located in the receiving space S between the surface of the wall member 13a or 13b and the retaining bricks 17a and 17b.

[0064] The holding bricks 17a and 17b are made of, for example, heat-resistant bricks. Figure 4 As shown, the retaining bricks 17a and 17b include a large first retaining brick 17a and a small second retaining brick 17b. The first retaining brick 17a holds multiple (two in the example) heaters 16, and the second retaining brick 17b holds one heater 16. The number of heaters 16 held by each retaining brick 17a and 17b is not limited to this embodiment. Furthermore, the number of retaining bricks 17a and 17b included in one heater 16 is not limited to this embodiment and may be one or three or more. By using retaining bricks 17a and 17b of different sizes, the size of the heating unit 14 can be appropriately adjusted according to the scale of the manufacturing apparatus 1.

[0065] Hereinafter, in the heating unit 14, the portion above the center position in the vertical direction Z is referred to as the "upper portion of the heating unit", but preferably the portion above the position 1 / 4 from the upper end is referred to as the "upper portion of the heating unit". Furthermore, the portion below the center position in the vertical direction Z is referred to as the "lower portion of the heating unit", but preferably the portion below the position 1 / 4 from the lower end is referred to as the "lower portion of the heating unit".

[0066] The holding bricks 17 a and 17 b have a surface 21 for partitioning the accommodation space S of the heater 16 , an exhaust portion 22 for exhausting air from the accommodation space S of the heater 16 , and an insertion hole 23 for attaching the thermometer 19 .

[0067] Each surface 21 of each retaining brick 17a, 17b is located at a position separated from the wall members 13a, 13b in the thickness direction Y and faces the wall members 13a, 13b. Thus, a space S for accommodating the heater 16 is defined between each surface 21 and the wall members 13a, 13b. The surface 21 of the first retaining brick 17a and the surface 21 of the second retaining brick 17b are aligned in the thickness direction Y. This is not limiting; the surface 21 of the first retaining brick 17a and the surface 21 of the second retaining brick 17b may be offset in the thickness direction Y.

[0068] The exhaust section 22 includes an exhaust hole 24 formed through the retaining bricks 17a and 17b, and an exhaust pipe 25 connected to the exhaust hole 24. The exhaust hole 24 has an exhaust port 24a formed on the surface 21 of the retaining bricks 17a and 17b. The exhaust pipe 25 is connected to an exhaust device (not shown). To simplify the equipment structure, it is preferable to omit the exhaust pipe 25.

[0069] The exhaust section 22 is provided above the heating unit 14. Specifically, exhaust holes 24 and exhaust ports 24a are formed above the retaining bricks 17a and 17b. This allows the exhaust section 22 to be positioned away from the cooler 18, enabling efficient cooling by the cooler 18 and exhaust by the exhaust section 22.

[0070] Insertion holes 23 are formed in the upper portion of heating unit 14, i.e., in the upper portions of retaining bricks 17a and 17b. More specifically, insertion holes 23 are formed in retaining bricks 17a and 17b above heater 16. The position of insertion holes 23 is not limited to this embodiment. Insertion holes 23 are, for example, linear holes that penetrate retaining bricks 17a and 17b in the horizontal direction (width direction X or thickness direction Y).

[0071] Cooler 18 is provided below heating unit 14. Specifically, cooler 18 is positioned below retaining bricks 17a and 17b. Cooler 18 is positioned so as to contact the lower portions (lower surfaces) of retaining bricks 17a and 17b, but this is not limiting. A heat insulator or the like may be provided between cooler 18 and the lower surfaces of retaining bricks 17a and 17b.

[0072] The cooler 18 has a cooling nozzle 18a that blows cooling air A toward the wall members 13a and 13b. The cooling nozzle 18a is configured to be flat, but is not limited to the shape of this embodiment. The cooling nozzle 18a is configured to blow cooling air A toward the lower part of the wall members 13a and 13b in the storage space S of the heater 16. The cooling nozzle 18a has a supply port 18b that supplies cooling air A to the storage space S of the heater 16. Figure 4 As shown in FIG. 1 , the supply port 18 b is configured in a horizontally elongated quadrilateral shape, but the shape of the supply port 18 b is not limited to this embodiment.

[0073] The thermometer 19 is provided at the upper portion of the heating unit 14. Specifically, the thermometer 19 is inserted into the insertion hole 23 formed in the retaining bricks 17a and 17b and its front end portion is in contact with the wall members 13a and 13b. A receiving portion 26 for receiving the front end portion of the thermometer 19 is provided at the upper portion of the wall members 13a and 13b. The receiving portion 26 is configured to be cylindrical, but is not limited to this shape. The front end portion of the thermometer 19 is accommodated in the interior of the receiving portion 26, thereby being able to maintain contact with the wall members 13a and 13b and measure the temperature of the wall members 13a and 13b with good accuracy. In the present embodiment, the thermometer 19 is composed of, for example, a thermocouple, but the structure of the thermometer 19 is not limited to the present embodiment.

[0074] The partition member 20 is a member for partitioning the storage space S of the heater 16 together with the holding bricks 17a and 17b. The partition member 20 is made of, for example, the same refractory bricks as the holding bricks 17a and 17b.

[0075] like Figure 1 as well as Figure 2 As shown, the second conveying rollers 15 are arranged inside the annealing furnace 3 (inside the wall members 13a to 13d). The second conveying rollers 15 are also called annealing rollers. The second conveying rollers 15 are configured as a pair of rollers that clamp the ends of the glass ribbon GR in the width direction X in the thickness direction Y. The second conveying rollers 15 can also be rollers of the end support type arranged so as to span the entire area of ​​the glass ribbon GR in the width direction X. However, in this embodiment, they are cantilever rollers. The second conveying rollers 15 are arranged in multiple stages along the vertical direction Z.

[0076] like Figure 1 as well as Figure 2 As shown, the cooling chamber 4 is an area for cooling the glass ribbon GR to near room temperature. Third conveying rollers 27 are arranged within the cooling chamber 4. The third conveying rollers 27 are configured as a pair of rollers that clamp the ends of the glass ribbon GR in the width direction X in the thickness direction Y. The third conveying rollers 27 may also be rollers of the double-ended type arranged across the entire width direction X of the glass ribbon GR. However, in this embodiment, they are cantilever rollers. The third conveying rollers 27 are arranged in multiple stages along the vertical direction Z.

[0077] In the present embodiment, both end portions in the width direction X of the glass ribbon GR obtained by the manufacturing apparatus 1 include ear portions having a thickness greater than that of the central portion in the width direction X due to the influence of shrinkage during the forming process.

[0078] like Figure 1 as well as Figure 2 As shown, the cutting chamber 5 is an area for cutting the glass ribbon GR into predetermined sizes to obtain glass sheets G as glass products. A cutting device (not shown) is disposed within the cutting chamber 5 to cut the glass ribbon GR. In this embodiment, the cutting device cuts the glass ribbon GR by forming score lines on the glass ribbon GR and then breaking the glass ribbon GR along the score lines. However, this is not limited to this method. The cutting device may also use laser cutting, laser melting, or other cutting methods, for example.

[0079] Glass sheet G is a raw glass sheet (mother glass sheet) from which one or more finished glass sheets are obtained. The thickness of the finished glass sheet ranges from 0.2 mm to 10 mm, and the dimensions range from 700 mm x 700 mm to 3500 mm x 3500 mm. These finished glass sheets are used, for example, as substrates or cover glass for displays.

[0080] Hereinafter, a method for manufacturing a glass ribbon GR and a glass sheet G as glass articles using the manufacturing apparatus 1 having the above-described structure will be described. Figure 5 As shown, the method mainly includes a forming step S1, an annealing step S2, a cooling step S3 and a cutting step S4.

[0081] like Figure 1 as well as Figure 2 As shown, in the forming step S1, in the forming furnace 2, molten glass GM is supplied to the groove portion 8 of the forming body 6. The molten glass GM overflowing from the groove portion 8 in two directions flows down along the vertical surface portions 11 and the inclined surface portions 12 and rejoins at the lower end portion 6a. Thus, a band-shaped glass ribbon GR is continuously formed from the molten glass GM. The first conveying roller 7 conveys the glass ribbon GR downward while holding the end portion of the glass ribbon GR in the width direction X so as to maintain a constant width.

[0082] Next, in the annealing step S2, the glass ribbon GR is annealed while being conveyed by the second conveying rollers 15 in the annealing furnace 3. In the annealing step S2, the wall members 13a and 13b are heated to a temperature of 500°C to 900°C. The heating temperature of the wall members 13a and 13b is more preferably 600°C to 800°C. Within this temperature range, a temperature gradient is set in the annealing furnace 3.

[0083] In the annealing step S2, the wall members 13a and 13b are heated by the heater 16 while the wall members 13a and 13b are cooled by the cooler 18. Specifically, while the wall members 13a and 13b are constantly heated by the main body 16a of the heater 16, cooling air A is continuously blown from the cooler 18 toward the wall members 13a and 13b. The temperature of the cooling air A is, for example, set to 20°C or higher and 30°C or lower, but is not limited to this range. Furthermore, in the annealing step S2, the heating unit 14 exhausts the air in the housing space S of the heater 16 to the outside using the exhaust unit 22 (exhaust step).

[0084] In the annealing step S2 , the temperature of the wall members 13 a and 13 b is measured by the thermometer 19 of the heating unit 14 , thereby managing the temperature in the annealing furnace 3 .

[0085] In the subsequent cooling step S3, the glass ribbon GR is cooled to near room temperature while being conveyed by the third conveying rollers 27 in the cooling chamber 4. Subsequently, in the cutting step S4, the glass ribbon GR is cut in the cutting chamber 5 to obtain glass sheets G. The cutting step S4 includes a first cutting step of cutting the glass ribbon GR along the width direction X at predetermined lengths to obtain glass sheets G, and a second cutting step of cutting and removing the ear portions at both ends of the glass sheet G in the width direction X. It should be noted that the post-forming steps of the forming step S1 are not particularly limited. For example, the method may also include a cleaning step, an inspection step, a packaging step, and the like.

[0086] According to the method for manufacturing a glass article according to the embodiment described above, while the wall members 13a and 13b are heated by the heater 16, they are simultaneously cooled by the cooler 18. With this configuration, when the heating temperature of the wall members 13a and 13b is increased, the heating value of the heater 16 can be increased, while the cooling capacity of the cooler 18 can be reduced (for example, by reducing the flow rate of the refrigerant). Conversely, when the heating temperature of the wall members 13a and 13b is decreased, the heating value of the heater 16 can be reduced, while the cooling capacity of the cooler 18 can be increased (for example, by increasing the flow rate of the refrigerant). This improves responsiveness and allows precise adjustment of the heating temperature of the wall members 13a and 13b. As a result, high-quality glass articles with reduced strain can be stably manufactured.

[0087] It should be noted 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 modified in various ways without departing from the spirit of the present invention.

[0088] In the above embodiment, an example of manufacturing a glass article by the overflow down-draw method is shown, but the present invention is not limited thereto. For example, the present invention can also manufacture a glass article by the slot down-draw method.

[0089] In the above embodiment, a heating unit 14 is shown with a cooler 18 positioned below the retaining bricks 17a and 17b. However, the present invention is not limited to this configuration. For example, the cooler 18 may be positioned above the retaining bricks 17a and 17b. In this case, the thermometer 19 is preferably inserted through an insertion hole 23 formed below the cooler 18, i.e., below the retaining bricks 17a and 17b, and positioned below the heating unit 14.

[0090] Specifically, in the annealing step S2, it is preferred that the temperature of the wall members 13a and 13b be measured using a thermometer 19 disposed at one of the upper and lower portions of the heating unit 14, and that cooling air A be blown toward the wall members 13a and 13b using a cooler 18 (cooling nozzle 18a) disposed at the other of the upper and lower portions of the heating unit 14. This allows the thermometer 19 to accurately measure the temperature of the wall members 13a and 13b without being affected by the cooling air A.

[0091] When the cooler 18 is arranged above the holding bricks 17a and 17b as described above, it is desirable that the exhaust holes 24 of the exhaust portion 22 are formed in the lower portions of the holding bricks 17a and 17b.

[0092] In the above embodiment, cooling air A is exemplified as the cooling medium used in the cooler 18. However, the present invention is not limited to this configuration. A fluid such as water or a gas other than air (such as nitrogen or steam) may also be used as the cooling medium.

[0093] While the above embodiment illustrates a vent portion 22 having vent holes 24 extending through the retaining bricks 17a and 17b, the present invention is not limited to this configuration. Alternatively, the vent portion 22 may form a gap between the first retaining brick 17a and the second retaining brick 17b, and exhaust gas may be discharged through this gap. In this case, the vent is formed between the surface 21 of the first retaining brick 17a and the surface 21 of the second retaining brick 17b.

[0094] In the above embodiment, the main body 16a of the heater 16 is exemplified as an elongated portion extending in the vertical direction Z. However, the present invention is not limited to this configuration. For example, the main body 16a of the heater 16 may be configured as an elongated portion extending in the horizontal direction.

Claims

1. A method for manufacturing a glass article, comprising an annealing step of annealing a glass ribbon in an annealing furnace, The method for manufacturing the glass article is characterized in that: The annealing furnace includes: a wall member facing the glass ribbon; and a heating unit for adjusting the temperature of the wall member. The heating unit includes: a heater that heats the wall member; and a cooler that cools the wall member. In the annealing step, the wall member is heated by the heater and cooled by the cooler.

2. The method for manufacturing a glass article according to claim 1, wherein: The cooler has a cooling nozzle that blows gas toward the wall member.

3. The method for manufacturing a glass article according to claim 2, wherein: The cooling nozzle is configured in a flat shape.

4. The method for manufacturing a glass article according to claim 2 or 3, wherein: The heating unit includes a thermometer for measuring the temperature of the wall member. In the annealing step, the temperature of the wall member is measured using the thermometer disposed at one of the upper and lower portions of the heating unit, and the gas is blown toward the wall member using the cooling nozzle disposed at the other of the upper and lower portions of the heating unit.

5. The method for producing a glass article according to any one of claims 1 to 3, wherein: In the annealing step, the wall member is heated to a temperature of 500° C. or higher and 900° C. or lower.

6. The method for manufacturing a glass article according to claim 2 or 3, wherein: The annealing furnace includes a holding brick for holding the heater. The holding bricks have exhaust ports for exhausting the gas.

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