TW202146342A - Glass melting furnace, glass manufacturing apparatus and glass manufacturing method having a flame retardant layer and a heat resistant layer - Google Patents

Abstract

This invention relates to a glass melting furnace with an arched roof structure. The glass melting furnace has a flame retardant layer 25 having a block row in which a plurality of flame retardant blocks 23 are arranged in an arched shape; and a heat resistant layer 29 arranged above the flame retardant layer 25 and having a heat resistant block 27 with a porosity greater than that of the flame retardant blocks 23. The flame retardant layer 25 has a plurality of block segments which are formed by connecting a plurality of block rows along a length direction of the glass melting furnace; and a gap portion positioned among the plurality of block segments and absorbing thermal expansion of the flame retardant blocks 23 towards the length direction. The arched roof structure has a first heat insulating member 51 which surrounds an upper opening of the gap portion S to form a first space 45 by means of division inside. The first heat insulating member 51 is formed of a flame retardant material with a porosity of 50% or less.

Description

Glass melting furnace, glass manufacturing apparatus, and glass manufacturing method

The present invention relates to a glass melting furnace, a glass manufacturing apparatus, and a glass manufacturing method.

In order to melt glass, the temperature in the furnace becomes very high. The inner surface of the furnace wall, ceiling, etc. is made of refractory bricks that are resistant to the temperature in the furnace, and heat-resistant blocks are installed on the outside. The heat inside the furnace is not released to the outside.

In addition, a vaulted vaulted furnace roof structure with a vault shape is proposed, which uses electroformed bricks as refractory blocks, and is suitable for making the temperature in the furnace as high as the special glass to be melted. In the case of a high temperature of about 1650°C (refer to Patent Document 1). According to Patent Document 1, the volatile gas (furnace gas) originating from the glass leaks to the outside of the furnace through the joints between the refractory blocks, so that the heat-resistant blocks arranged on the upper layer of the refractory blocks are corroded, and the self-arching type The heat dissipation of the furnace roof structure is increased. In this regard, a structure for blocking gas leakage (gas leakage blocking layer) has been proposed, which has a dense amorphous refractory provided so as to cover the joints between the refractory blocks. [Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2013/179409

[Problems to be Solved by Invention]

However, the above-mentioned dense amorphous refractory reacts not only with the volatile gas leaking from the joints between the refractory blocks, but also with the vitreous seeping from the refractory blocks, thereby causing the refractory blocks and the dense amorphous refractory to be fixed. Therefore, even if the dense unshaped refractory and the heat-resistant block are corroded at the joints between the refractory blocks and their surroundings, it may not be possible to replace them. If the dense unshaped refractories and heat-resistant blocks are not arranged, the heat dissipation from the arched furnace top structure will increase, which will lead to increased energy loss. In addition, the refractory blocks constituting the dome-roof structure expand at the time of temperature rise in the stage before the start of glass production. In the longitudinal direction of the glass melting furnace, space is reserved for the expansion of the refractory blocks by pre-arranged gaps between the blocks. However, since the gap of the gap portion is larger than the joint between the refractory blocks, the heat dissipation is large. Therefore, when the dense amorphous refractory or the like is arranged so as to cover the gap portion, the above-mentioned fixation occurs remarkably, so even if the dense amorphous refractory or the like is eroded, it may not be possible to replace them.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a glass melting furnace, a glass manufacturing apparatus, and a glass manufacturing method which can replaceably arrange a dense amorphous refractory material in the joints, the gaps, and their surroundings. The heat-insulating members and heat-resistant blocks formed by etc. can reduce the heat dissipation from the arched furnace roof structure. [Technical means to solve problems]

The present invention includes the following constitutions. (1) A glass melting furnace, characterized in that it is a glass melting furnace with an arched roof structure, and includes: a refractory layer having a plurality of refractory blocks arranged in an arched block row; and a heat-resistant layer, It is arranged above the above-mentioned refractory layer, and has a heat-resistant block with a porosity larger than that of the above-mentioned refractory block; The above-mentioned refractory layer has: a plurality of blocks, which are formed by connecting a plurality of the above-mentioned block rows along the longitudinal direction of the above-mentioned glass melting furnace; Thermal expansion in the length direction; The above-mentioned arched roof structure includes a first heat insulating member that surrounds the upper opening of the above-mentioned gap portion and divides the inside to form a first space; The above-mentioned first heat insulating member is formed of a refractory material having a porosity of 50% or less. (2) A glass manufacturing apparatus including a melting furnace, a forming furnace, and a slow cooling furnace, The above-mentioned melting furnace is a glass melting furnace of (1). (3) A glass manufacturing method comprising a melting step, a forming step and a slow cooling step in this order, In the above-mentioned melting step, the glass melting furnace of (1) was used. [Effect of invention]

ADVANTAGE OF THE INVENTION According to this invention, a heat insulating member, a heat-resistant block, etc. can be arrange|positioned replaceably in a joint, a clearance part, and its periphery, and the amount of heat radiation from an arched roof structure can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. ＜Structure of Glass Melting Furnace＞ FIG. 1 is a schematic cross-sectional view of a glass melting furnace according to an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view of the glass melting furnace shown in Fig. 1 viewed from the side. FIG. 2 corresponds to the sectional view taken along the line II-II in FIG. 1 . 1 corresponds to the cross-sectional view taken along the line I-I in FIG. 2 .

As shown in FIG. 1 , the glass melting furnace 100 of the present embodiment includes a melting tank 11 for supplying glass raw materials to the inside, and an upper structure 13 covering the upper side of the melting tank 11 . In addition, although not shown, the burner for heating is provided in the upper structure 13, and the energization electrode is provided in the melting tank 11. The melting tank 11 is supported by a suitable supporting structure provided outside, but the supporting form is not limited to this.

The melting tank 11 and the upper structure 13 have shapes extending in the X direction. 1 shows a cross-sectional view of a plane perpendicular to the X direction, the X direction corresponds to the longitudinal direction of the melting tank 11 , and the Y direction corresponds to the short side direction of the melting tank 11 . The Z direction in FIG. 1 corresponds to the up-down direction of the glass melting furnace 100 .

The glass melting furnace 100 melts the glass raw material supplied to the inside of the melting tank 11 by burning the burner (not shown) of the upper structure 13 and applying a voltage to the current-carrying electrode (not shown) of the melting tank 11 . The melting tank 11 is provided with the bottom part 15 and the side wall part 17, and holds the molten glass G obtained by melting. Moreover, as shown in FIG. 2, the glass discharge path 35 which discharges the molten glass G hold|maintained inside the melting tank 11 is provided in the X direction downstream side of the glass melting furnace 100.

The upper structure 13 includes a horizontal wall member 19 that stands up from the side wall portion 17 of the melting tank 11 , and a ceiling member 21 that is arranged above the horizontal wall member 19 . As shown in FIG. 1, the lateral wall members 19 extend up and down, and the ceiling member 21 has a dome-shaped arch. Here, the so-called dome shape is a shape formed by extending a dome shape in which the central portion is raised upward in the horizontal direction (X direction). In this specification, the direction in which the arches (arcs) are formed in the dome shape is also referred to as the circumferential direction, and the direction in which the arched shapes are extended in the horizontal direction is also referred to as the longitudinal direction (X direction).

The ceiling member 21 (arch roof structure) includes: a refractory layer 25 having a block row in which a plurality of refractory blocks 23 are arranged in an arched shape; and a heat-resistant layer 29 arranged above the refractory layer 25 and having a porosity The refractory block 27 is larger than the refractory block 23 . As shown in FIG. 2 , the refractory layer 25 has: a plurality of block segments SEG1, SEG2, SEG3, and SEG4, which are formed by connecting a plurality of block rows along the length direction (X direction) of the glass melting furnace 100; and a gap S , which are located between the plurality of block segments SEG1 , SEG2 , SEG3 , and SEG4 to absorb the thermal expansion of the refractory block 23 in the longitudinal direction (X direction). The dome roof structure includes the first heat insulating member 51 that surrounds the upper opening 41 (see FIG. 4 ) of the gap portion S to define the first space 45 inside. The first heat insulating member 51 is formed of a refractory material having a porosity of 50% or less. The arched roof structure is provided with a joint heat insulating member 59 provided between the refractory layer 25 and the heat-resistant layer 29 to cover the joint between the refractory blocks 23, and the joint heat insulating member 59 is preferably made of a porosity of 50%. The following refractories are formed. Thereby, the leakage of volatile gas from the joint 57 between the refractory blocks 23 is prevented, and the heat insulation effect is improved, so the effect of reducing the amount of heat radiation from the arched furnace roof structure is exhibited. In addition, the arched roof structure may include a second heat insulating member 62 between the refractory layer 25 and the heat-resistant layer 29 , and the second heat insulating member 62 is formed to surround the upper portion of the joint 57 between the refractory blocks 23 and to be divided inside. The second space 61 (see FIG. 5 ). The second heat insulating member 62 is preferably formed of a refractory material having a porosity of 50% or less. Thereby, in addition to the above-mentioned effect, heat from the joint 57 is diffused, and local strong heating of the heat insulating layer 31 can be suppressed. The upper surface of the heat-resistant layer 29 is covered with the heat insulating member 33 . The refractory layer 25 is in the shape of a dome, so it is self-supported by gravity and is integrally formed, and has a plurality of block rows along the longitudinal direction, and the plurality of refractory blocks 23 are arranged in a dome shape in the circumferential direction. Group each specific number of block lines into 1 block segment.

＜Refractory layer＞ FIG. 3 is a schematic plan view of the refractory layer 25 viewed from above. In FIG. 3 , four block segments SEG1 , SEG2 , SEG3 , and SEG4 are shown in which the block rows in which 12 refractory blocks 23 are arranged in the circumferential direction are connected to three rows in the longitudinal direction.

The refractory blocks 23 in the block segment are arranged in a state of abutting against each other without a gap. That is, the contact part of the blocks of the refractory blocks 23 is smoothly formed so that the gap between the blocks is not large, and the adjacent blocks are formed in a shape corresponding to each other. A gap S with an interval ΔL is provided between the blocks along the longitudinal direction.

The gap portion S between the blocks functions as a concentrated expansion portion for absorbing the thermal expansion of the refractory block 23 in the longitudinal direction when the temperature rises in the stage before the start of glass production. Specifically, the gap S has a certain interval before the temperature rise of the glass melting furnace 100 starts, and becomes narrow due to the thermal expansion of the refractory block 23 during the temperature rise, but the gap S will not be completely blocked after the temperature rise, and the interval will be becomes ΔL. The interval between the gap portions S is, for example, 10 mm or more and 50 mm or less before the temperature rise is started, and is more than 0 mm and 20 mm or less after the temperature rise is completed.

The refractory block 23 has fire resistance and corrosion resistance to glass vapor (volatile gas). The refractory block 23 is preferably one or more kinds of electroformed bricks as refractories selected from the group consisting of alumina, zirconia, alumina-zirconia, and alumina-zirconia-silica piece. Refractory blocks such as silica and mullite can also be used as refractories. Further, in the present specification, the silicon dioxide-based substance used in the meaning of SiO ₂ as a main component, mullite and the like are also the same meaning. Here, the main component refers to a component whose content (for example, in the case of alumina-zirconia-silica _{, the total of Al 2} O ₃ , ZrO ₂ and SiO ₂ ) is 50 mass % or more.

The refractory block 23 used here can be appropriately selected according to the operating conditions of the glass melting furnace 100 . For example, in the case of an oxy-combustion glass melting furnace in which oxygen or a gas with an increased oxygen concentration is used as the combustion-supporting gas of the burner, electroformed bricks with high refractory temperature and high corrosion resistance are preferred, especially alumina - Electroformed bricks made of zirconia are preferred.

Compared with fired bricks, electroformed bricks have the following excellent characteristics: high corrosion resistance to molten glass G melted at high temperature, and it is not easy to contaminate molten glass G. In addition, electroformed bricks also have the characteristic that the specific resistance is lower than that of fired bricks.

Examples of the electroformed bricks include AZS (Al ₂ O ₃ -ZrO ₂ -SiO ₂ )-based electroformed bricks, zirconia-based electroformed bricks, or alumina-based electroformed bricks.

＜Insulation layer＞ As shown in FIGS. 1 and 2 , the heat insulating layer 31 including the first heat insulating member 51 (see FIG. 2 ) is preferably formed between the refractory layer 25 and the heat-resistant layer 29 . The heat insulating layer 31 further has the heat insulating blocks 30 and 60 and the heat insulating member 59 for joints. The heat insulating block 30 is arranged on the refractory layer 25 . The heat insulating member 59 for the joint is provided on the outer surface of the refractory layer 25 to cover the joint 57 between the refractory blocks 23 to prevent leakage of volatile gas from the joint 57 . The heat insulating block 60 is arrange|positioned on the heat insulating material 59 for joints. The insulating blocks 30, 60 are preferably formed of insulating monolithic refractories. In addition, it is preferable that the heat insulating material 59 for a joint is formed of a dense amorphous refractory. Furthermore, the heat insulating layer 31 can also be formed by coating a dense amorphous refractory or a heat insulating amorphous refractory so as to cover the outer surfaces of the refractory block 23 and the first heat insulating member 51 . In either case, the heat insulating layer 31 is integrally and airtightly formed on the outer surface of the refractory layer 25 . Thereby, even if the upward bulge caused by the expansion of the refractory blocks 23 occurs, the gaps between the refractory blocks 23 are not greatly vacant. In this way, the heat insulating layer 31 effectively prevents gas leakage and prevents the heat and volatile gas in the furnace from leaking to the outside.

The heat insulating member 59 for joints formed of the dense amorphous refractory forms a dense structure on the refractory block 23, thereby reliably preventing gas leakage. The bulk specific gravity of the dense amorphous refractory at 110° C. is preferably 3.0 or more, more preferably 3.1 or more.

The dense amorphous refractory is preferably a component that strongly reacts with volatile gas. In this case, as the alumina substance, the refractory contains 85 mass % or more, more preferably 90 mass % or more of Al _{2 is used.} O ₃ refractory. As a dense amorphous refractory, the high alumina self-flow castable (model: RF-SRC1) etc. by AGC Ceramics Co., Ltd. are mentioned, for example. The bulk specific gravity at 110° C. of the heat-insulating monolithic refractory is preferably 1.2 or less, more preferably 1.1 or less. Moreover, the thermal conductivity at 1000°C of the heat insulating monolithic refractory is preferably 0.7 W/(m·K) or less, more preferably 0.6 W/(m·K) or less. As the heat insulating amorphous refractory, alumina, zirconia, alumina-zirconia, alumina-zirconia-silica, etc. can be used, but the heat resistance and corrosion resistance to glass are different. In other words, alumina-zirconia is preferred. As the alumina-zirconia substance, _{the total content of Al 2} O ₃ and ZrO ₂ is preferably 80% by mass or more, more preferably 85% by mass or more. As a heat insulating monolithic refractory, THERMOTECT WALL (registered trademark) (manufactured by AGC Ceramics Co., Ltd., model number: TMT1600) etc. are mentioned, for example.

<Heat-resistant layer> The heat-resistant layer 29 includes a plurality of heat-resistant blocks 27 and 28, and includes a part of the first heat insulating member 51 (heat insulating plate 49). The heat-resistant block 27 is arranged on the heat insulating layer 31 . The heat-resistant block 28 is preferably arranged on the first heat insulating member 51 . Furthermore, the heat-resistant layer 29 may not include a part of the first heat insulating member 51 (the heat insulating plate 49 ). In this case, the heat insulating plate 49 is included in the heat insulating layer 31 . The heat-resistant blocks 27 and 28 improve the thermal insulation effect of the arched furnace roof structure, so that the heat in the furnace is not easily released to the outside. The heat-resistant blocks 27 and 28 are preferably formed of an alumina-zirconia refractory. Compared with the refractory of the refractory block 23, the refractory material is lighter in weight, smaller in bulk specific gravity, and lower in thermal conductivity. Thereby, the weight increase of the ceiling member 21 itself can be suppressed, and the heat insulating effect can be improved.

The heat-resistant blocks 27 and 28 preferably have a bulk specific gravity of 1.2 or less at 110°C and a thermal conductivity of 0.7 W/(m·K) or less at 1000°C. Thereby, an arched roof structure excellent in light weight and heat insulation can be provided.

The heat-resistant blocks 27 and 28 are preferably formed of an unshaped refractory material, and may be preliminarily formed (coated) and dried into blocks, which are placed and fixed on the refractory blocks 23 and the first heat insulating member 51 . In addition, it can also be formed by forming the monolithic refractory etc. in a desired position on the refractory block 23 and the first heat insulating member 51 by spraying, casting, trowel leveling, pressing, or the like. shape required. The heat-resistant blocks 27 and 28 can be formed by, for example, THERMOTECT WALL (registered trademark) (manufactured by AGC Ceramics Co., Ltd., model: TMT1600). In addition, the heat-resistant blocks 27 disposed on the heat-insulating blocks 30 and 60 can reduce the heat dissipation from the arched furnace top structure by the heat-insulating blocks 30 and 60, so it can also be a class A refractory and heat-insulation that is cheaper. bricks etc.

<Insulation member> The insulation member 33 is preferably a fibrous fabric or a solid board containing inorganic fibers. The heat insulating member 33 is replaceably arranged on the heat-resistant blocks 27 and 28 . The inorganic fibers are preferably _{man-made mineral fibers containing SiO 2} , MgO and CaO, or ceramic fibers. By forming the thermal insulation member 33 with the fiber fabric, the degree of freedom of arrangement and the degree of freedom of the shape of the thermal insulation member 33 can be improved. In addition, these inorganic fibers have excellent heat resistance, and are hardly thermally damaged even when the temperature of the parts in contact with the heat-resistant blocks 27 and 28 reaches a high temperature of 900°C to 1300°C. The thickness of the heat insulating member 33 is 10 mm to 100 mm, preferably 30 mm to 70 mm, and more preferably 40 mm to 60 mm.

When molten glass G is glass containing alkali metal (for example, soda lime glass), Na component is contained in the volatile gas from the furnace. In addition, even if the molten glass G is an alkali-free glass that does not substantially contain an alkali metal, when the refractory block 23 is composed of a refractory material containing a Na component, the Na component contained in the refractory block 23 is volatilized, and the result is from the furnace The volatile gas inside also contains Na component. When the Na component of the volatile gas is condensed on the heat insulating layer 31, the heat insulating layer 31 reacts with the Na component, so that the melting point of the heat insulating layer 31 is lowered. Therefore, if the heat insulating layer 31 is exposed to the volatile gas, it will be melted and damaged, and the replacement cycle of the heat insulating layer 31 will be advanced. The same is true for the heat-resistant blocks 27 and 28 , and the replacement cycle of the heat-resistant blocks 27 and 28 will be advanced due to melting loss.

Therefore, the temperature of the portion of the heat insulating member 33 in contact with the heat-resistant blocks 27 and 28 is preferably 900°C or higher. The reason for this is that the temperature at which the Na component of the volatile gas agglomerates is approximately 800 to 950°C, and the agglomeration does not easily occur at a temperature of 900°C or higher. In addition, the temperature of the part in contact with the heat-resistant blocks 27 and 28 is the temperature measured using a thermocouple. Therefore, the upper surfaces of the heat-resistant blocks 27 and 28 are preferably covered by the heat insulating member 33 . According to this configuration, the heat-resistant blocks 27 and 28 are less likely to aggregate the Na component of the volatile gas, and the damage of the heat-resistant blocks 27 and 28 can be suppressed.

On the other hand, since aggregation of the Na component of the volatile gas occurs, the heat insulating member 33 is preferably replaced according to the aggregation state or periodically. The heat insulating member 33 is a member disposed on the outermost side of the ceiling member 21 , so the replacement operation does not require disassembly of the furnace body, and can be completed by a simple operation.

Furthermore, as described above, a solid board containing inorganic fibers may be used for the heat insulating member 33 . As a solid board, boards, such as FINEFLEX (registered trademark) 1300 cardboard manufactured by NICHIAS Co., Ltd., etc. are mentioned.

<The specific structure of the heat insulation layer between the blocks of the refractory block> FIG. 4 is an enlarged partial cross-sectional view of the arrangement part P of the gap S of the ceiling member 21 shown in FIG. 2 . In the refractory layer 25, a gap S is provided between the refractory block 23 of the segment SEG1 and the refractory block 23 of the segment SEG2.

In the heat insulating layer 31 arranged on the upper layer of the refractory layer 25, the first space 45 surrounding the upper opening 41 is provided at the position of the upper opening 41 of the gap portion S. The space of the first space 45 includes a rectangular cross-section having a length L in the X direction (longitudinal direction) and a height H in the Z direction, and is continuous in the Y direction. The first space 45 is composed of a pair of heat insulating walls 47A, 47B disposed at a position apart from the upper opening 41 by about L/2, a heat insulating plate 49 disposed on the heat-resistant layer 29 facing the upper opening 41 , and a refractory block 23 is formed by dividing the upper surface. The heat in the furnace and the volatile gas released from the gap S are enclosed in the first space 45 by the first heat insulating member 51 composed of the pair of heat insulating walls 47A and 47B and the heat insulating plate 49 .

The first heat insulating member 51 is formed of a refractory material having a porosity of 50% or less. Thereby, the intensity|strength of the 1st heat insulating member 51 can be ensured, and the heat insulating effect of the arched roof structure can be improved. The porosity of the first heat insulating member 51 is preferably 40% or less, more preferably 30% or less, and more preferably 20% or less. In addition, the porosity and bulk specific gravity in this specification are measured in accordance with the "measurement method of apparent porosity, water absorption rate, and specific gravity of refractory bricks" of JIS R2205:1992. The first heat insulating member 51 is preferably one or more refractory materials selected from the group consisting of alumina, zirconia, alumina-zirconia, and alumina-zirconia-silica. Thereby, heat resistance and corrosion resistance to volatile gas can be improved. As a refractory, the high alumina self-flow castable (model number: RF-SRC1) etc. by AGC Ceramics Co., Ltd. are mentioned, for example. Moreover, it is preferable that the 1st heat insulating material 51 is an alumina-based refractory having a bulk specific gravity of 3.0 or more at 110° C. and containing 85 mass % or more of Al ₂ O _{3 .} Thereby, a dense structure can be constructed, gas leakage can be reliably prevented, and the corrosion resistance to volatile gas can be improved. Also, the first heat insulating member 51 is preferably selected from the group consisting of zircon, alumina-zircon, sillimanite, spinel, mullite, and dense zircon One or more of the refractories. Thereby, heat resistance and corrosion resistance to volatile gas can be improved.

The first heat insulating member 51 may be formed by spraying, casting, trowel leveling, punching, etc. of an unshaped refractory, but it may be formed by disposing a member preliminarily formed in a block shape on the heat-resistant layer 29 and the heat-insulating layer. 31 corresponds to the form of the position.

In addition, the form of the heat insulating plate 49 may be a double-layer block formed of the same refractory material as the heat-resistant block 28 on the upper side and a refractory material with a porosity of 50% or less on the lower side. Thereby, the assembling operation and replacement operation of the heat insulating plate 49 are not complicated, and the manufacturing cost and the maintenance cost can be reduced.

The height H of the first space 45 is preferably 20 mm or more. The height H is more preferably 25 mm or more, and still more preferably 30 mm or more. In this case, the heat from the gap S is diffused in the first space 45, and the position just above the gap S of the heat insulating plate 49 is not heated intensively. As a result, heat is uniformly transferred from the heat insulating plate 49 to the heat-resistant layer 29 over a wide range, and a sudden temperature rise of the heat-resistant layer 29 is suppressed. In addition, the higher the height H of the first space 45, the larger the area of the first heat insulating member 51 exposed in the first space 45 can be secured. Therefore, the heat entering from the furnace through the gap S is converted to the first heat insulating member 51 by the heat entering the furnace. large area for heat exchange.

Moreover, it is preferable that the ratio H/L of the height H of the 1st space 45 and the length L of the longitudinal direction of the 1st space is 0.1-1. The ratio H/L is more preferably 0.2 or more, and still more preferably 0.3 or more. Moreover, the ratio H/L is more preferably 0.9 or less, and still more preferably 0.8 or less.

Preferably, the upper opening 41 of the gap S is formed with a groove 53 wider in the longitudinal direction than the gap S, and a cover member 55 covering the upper opening 41 is disposed in the groove 53 . The cover member 55 shields the heat and volatile gas from the furnace, and reduces the amount of heat and volatile gas entering the first space 45 through the gap S.

Moreover, it is preferable to provide the heat insulating material 59 for joints in the heat insulating layer 31, and the heat insulating material 59 for the joints covers the joints 57 between the refractory blocks 23 and is made of the same material as the first heat insulating material 51. . In this case, it is preferable to arrange|position the heat insulating block 60 which consists of the same material as the heat insulating block 30 on the heat insulating material 59 for joints. The joint heat insulating material 59 is disposed to cover the joint 57 , thereby suppressing the heat from the furnace and the volatile gas from concentrating on the thermal insulation layer 31 at the joint 57 . In addition, the shape of the heat insulating material 59 for joints is not limited to the plate shape shown in FIG.

Fig. 5 is a partially enlarged cross-sectional view showing a joint portion of an example of the second heat insulating member. Fig. 6 is a partially enlarged cross-sectional view showing a joint portion of an example of the second heat insulating member and the heat insulating plate. The arched roof structure may include the second heat insulating member 62 shown in FIGS. 5 and 6 in place of the heat insulating member 59 for joints shown in FIG. 4 . As shown in FIG. 5, the 2nd heat insulating member 62 may be comprised so that the upper part of the joint 57 may be enclosed in a cross-sectional gate shape, and the 2nd space 61 may be divided and formed inside. According to this configuration, the heat and volatilized gas from the furnace enter the second space 61 through the joint 57 . Thereby, the heat from the joint 57 is diffused, and the heat insulating layer 31 can be suppressed from being strongly heated locally. In addition, the flow of the volatile gas from the joint 57 is relaxed, and the inflow of the volatile gas into the heat insulating layer 31 can be suppressed.

Moreover, as shown in FIG. 6, the heat insulation board 63 which consists of the same material as the 2nd heat insulation member 62 may be arrange|positioned in the 2nd space 61 in the said 2nd heat insulation member 62. By covering the directly above the seam 57 with the heat insulating plate 63, the heat insulating effect and the shielding effect of the volatile gas can be further improved.

As described above, according to the glass melting furnace of the present embodiment, even if the gap portion S is provided as a space for the thermal expansion of the refractory block 23, the heat-resistant block 27 and the heat insulating layer 31 due to heat dissipation from the gap portion S are not easily generated. melting loss. Therefore, the glass melting furnace 100 can be configured so that the first heat insulating member 51 , the heat-resistant blocks 27 and 28 , the heat insulating member 33 and the like can be easily replaced without lowering the thermal efficiency, thereby improving the maintainability and reducing the cost.

<Glass manufacturing apparatus and glass manufacturing method> Next, the glass manufacturing apparatus and the glass manufacturing method which use the glass melting furnace of this embodiment as a melting furnace are demonstrated. Fig. 7 is a flow chart showing the sequence of the glass manufacturing method.

The glass raw material is supplied into the glass melting furnace, and the flame of the burner is radiated to the glass raw material, whereby the glass raw material is heated and melted (melting step S1 ). The glass raw material can also be heated by heating by the flame of a burner, and energizing by applying a voltage to a plurality of energizing electrodes.

The molten glass obtained by melting the glass raw material is formed in a forming furnace installed on the downstream side of the glass melting furnace (forming step S2). The formed glass is slowly cooled in a slow cooling furnace installed on the downstream side of the forming furnace, and becomes a glass article (slow cooling step S3 ).

To obtain glass sheets as glass items, for example, use the float method. The float method is a method of forming a ribbon glass ribbon from molten glass introduced into molten metal (eg, molten tin) contained in a molten metal tank. The glass ribbon is pulled out from the molten metal, and it is cooled slowly while being conveyed in a slow cooling furnace, and becomes a plate glass. After the plate glass is unloaded from the slow cooling furnace, it is cut into a predetermined size and shape by a cutting machine, and it becomes a glass plate as a product.

Moreover, a fusion method can also be used as another shaping|molding method to obtain a glass plate. The fusion method is a method as follows: the molten glass overflowing from the upper edges of the left and right sides of the gutter-shaped member flows down along the left and right sides of the gutter-shaped member, and merges at the lower edges where the left and right sides meet, thereby forming a belt. Sheet glass ribbon. The molten glass ribbon is gradually cooled while moving downward in the vertical direction, and becomes plate glass. The plate glass is cut into a predetermined size and shape by a cutting machine, and becomes a glass plate as a product.

In this way, the present invention is not limited to the above-mentioned embodiments. Combining the respective structures of the embodiments and making changes and applications based on the descriptions in the specification and well-known technologies are also intended to be included in the claims of the present invention. within the range. This application is based on Japanese Patent Application No. 2020-066081 filed on April 1, 2020, the contents of which are incorporated herein by reference.

11: Melting tank 13: Superstructure 15: Bottom 17: Side wall 19: Transverse wall members 21: Ceiling components 23: Refractory block 25: refractory layer 27, 28: Heat resistant block 29: Heat-resistant layer 30,60: Insulation block 31: Insulation layer 33: Thermal insulation components 35: Glass discharge path 41: upper opening 45: Space 1 47A, 47B: Thermal Insulation Walls 49: Insulation board 51: 1st heat insulating member 53: Groove 55: Cover member 57: Seams 59: Thermal Insulation for Joints 61: 2nd space 62: Second heat insulating member 63: Insulation board 100: Glass melting furnace G: molten glass H: height L: length S: Clearance SEG1: block segment SEG2: Chunks SEG3: Chunks SEG4: Chunks ΔL: interval

FIG. 1 is a schematic cross-sectional view of a glass melting furnace according to an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view of the glass melting furnace shown in Fig. 1 viewed from the side. FIG. 3 is a schematic plan view of the refractory layer viewed from above. Fig. 4 is a partially enlarged cross-sectional view showing an enlarged arrangement portion of the gap portion of the ceiling member shown in Fig. 2 . Fig. 5 is a partially enlarged cross-sectional view showing a joint portion of an example of the second heat insulating member. Fig. 6 is a partially enlarged cross-sectional view showing a joint portion of an example of the second heat insulating member and the heat insulating plate. Fig. 7 is a flow chart showing the sequence of the glass manufacturing method.

23: Refractory block

25: refractory layer

27: Heat resistant block

28: Heat resistant block

29: Heat-resistant layer

30: Insulation block

31: Insulation layer

33: Thermal insulation components

41: upper opening

45: Space 1

47A: Thermal Insulation Wall

47B: Thermal Insulation Wall

49: Insulation board

51: 1st heat insulating member

53: Groove

55: Cover member

57: Seams

59: Thermal Insulation for Joints

60: Insulation block

H: height

L: length

S: Clearance

SEG1: block segment

SEG2: Chunks

ΔL: interval

Claims (20)

A glass melting furnace is characterized in that it is a glass melting furnace with an arched roof structure, and includes: a refractory layer having a block row in which a plurality of refractory blocks are arranged in an arched shape; and a heat-resistant layer arranged on Above the above-mentioned refractory layer, there is a heat-resistant block with a porosity greater than that of the above-mentioned refractory block; The above-mentioned refractory layer has: a plurality of blocks, which are formed by connecting a plurality of the above-mentioned block rows along the longitudinal direction of the above-mentioned glass melting furnace; Thermal expansion in the length direction; The above-mentioned arched roof structure includes a first heat insulating member that surrounds the upper opening of the above-mentioned gap portion and divides the inside to form a first space; The above-mentioned first heat insulating member is formed of a refractory material having a porosity of 50% or less. The glass melting furnace according to claim 1, wherein a heat insulating layer including the first heat insulating member is formed between the refractory layer and the heat-resistant layer. The glass melting furnace according to claim 1 or 2, wherein the first heat insulating member is selected from the group consisting of alumina, zirconia, alumina-zirconia, and alumina-zirconia-silica One or more of the refractories. The glass melting furnace according to claim 1 or 2, wherein the first heat insulating member is an alumina refractory having a bulk specific gravity of 3.0 or more at 110°C and containing 85 mass % or more of Al ₂ O _{3 .} The glass melting furnace according to claim 1 or 2, wherein the first heat insulating member is selected from zircon, alumina-zircon, sillimanite, spinel, mullite and dense Refractory of one or more kinds in the group consisting of zircon. The glass melting furnace according to claim 1 or 2, wherein the height of the first space is 20 mm or more. The glass melting furnace according to claim 1 or 2, wherein a ratio H/L of the height H of the first space to the length L of the longitudinal direction of the first space is 0.1 to 1. The glass melting furnace according to claim 1 or 2, wherein an upper portion of the gap portion is opened, and a groove portion wider in the longitudinal direction than the gap portion is formed, A cover member covering the upper opening is arranged in the groove portion. The glass melting furnace according to claim 1 or 2, wherein the heat-resistant block is arranged on the first heat insulating member. The glass melting furnace according to claim 1 or 2, wherein the arched roof structure is provided with a heat-insulating member for a joint between the refractory layer and the heat-resistant layer, and the heat-insulating member for a joint covers the joint between the refractory blocks set by sewing; The above-mentioned heat insulating material for joints is formed of a refractory material having a porosity of 50% or less. The glass melting furnace according to claim 1 or 2, wherein the arched roof structure includes a second heat insulating member between the refractory layer and the heat-resistant layer, and the second heat insulating member surrounds the joint between the refractory blocks. The upper part is divided on the inner side to form a second space; The second heat insulating member is formed of a refractory material having a porosity of 50% or less. The glass melting furnace according to claim 1 or 2, wherein the upper surface of the heat-resistant block is covered with a heat insulating member. The glass melting furnace according to claim 12, wherein the above-mentioned heat insulating member is a fibrous fabric or a solid board containing inorganic fibers. The glass melting furnace of claim 13, wherein the inorganic fibers include man-made mineral fibers or ceramic fibers _{containing SiO 2 , MgO and CaO.} The glass melting furnace of claim 12, wherein the temperature of the portion of the heat insulating member in contact with the heat-resistant block is 900°C or higher. The glass melting furnace of claim 1 or 2, wherein the refractory block is selected from the group consisting of alumina, zirconia, alumina-zirconia and alumina-zirconia-silica. More than one type of electroformed brick as refractory. The glass melting furnace according to claim 1 or 2, wherein the heat-resistant block is formed of an alumina-zirconia refractory. The glass melting furnace of claim 17, wherein the bulk specific gravity of the heat-resistant block at 110°C is 1.2 or less, and the thermal conductivity at 1000°C is 0.7 W/(m·K) or less. A glass manufacturing apparatus comprising a melting furnace, a forming furnace and a slow cooling furnace, The above-mentioned melting furnace is the glass melting furnace of any one of claims 1 to 18. A glass manufacturing method, which comprises a melting step, a forming step and a slow cooling step in sequence, In the above-mentioned melting step, the glass melting furnace of any one of claims 1 to 18 is used.

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