CN116621424A

CN116621424A - Glass melting furnace, glass product manufacturing apparatus, and glass product manufacturing method

Info

Publication number: CN116621424A
Application number: CN202310088338.6A
Authority: CN
Inventors: 增田健一
Original assignee: Asahi Glass Co Ltd
Current assignee: AGC Inc
Priority date: 2022-02-21
Filing date: 2023-01-17
Publication date: 2023-08-22
Also published as: KR20230125744A; JP2023121645A; TW202337847A

Abstract

The present invention relates to a glass melting furnace, a glass product manufacturing apparatus, and a glass product manufacturing method. The present invention relates to a glass melting furnace capable of obtaining molten glass with improved thermal efficiency and suppressed variation in composition. The glass melting furnace has an upstream wall and a downstream wall which are opposite to each other, and a first side wall and a second side wall which are opposite to each other, wherein a first burner group is arranged on the first side wall, a second burner group is arranged on the second side wall, 70% or more of the total combustion heat per 1 hour supplied by the first burner group and the second burner group is supplied by an oxygen combustion-supporting burner, the distance from the upstream wall to the downstream wall is L, the direction of L is referred to as an extending direction, and the burner located on the most upstream side in the first burner group is referred to as a first most upstream burner, and the first most upstream burner is arranged at a position within 0.15L from the upstream wall along the extending direction.

Description

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

Technical Field

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

Background

A glass manufacturing apparatus for manufacturing glass articles has a glass melting furnace. The glass raw material is melted in the glass melting furnace, thereby forming molten glass.

In general, a glass melting furnace has an upstream wall and a downstream wall opposite to each other, two side walls opposite to each other, and an upper surface and a bottom surface, thereby dividing a lower melting portion and an upper ceiling portion.

The upstream wall is provided with an inlet for glass raw material, and the downstream wall is provided with a discharge port for molten glass, a passage for conveying the molten glass to another chamber, and the like. In addition, a plurality of burners are provided on the ceiling portion side of the side wall in order to heat and melt the glass in the melting portion.

The burners are roughly classified into air-assisted burners and oxygen-assisted burners. In the air-assisted burner, air is used as a gas to be mixed with a fuel such as natural gas and/or heavy oil, and in the oxygen-assisted burner, oxygen is used as a gas to be mixed with a fuel.

Prior art literature

Patent literature

Patent document 1: international publication No. 2011/136086

Disclosure of Invention

Problems to be solved by the invention

Compared with an air-assisted combustion burner, the oxygen-assisted combustion burner has good thermal efficiency, can reduce the amount of gas used, and can inhibit CO ₂ Is a discharge amount of (2). In addition, the oxygen combustion-supporting burner can also inhibit NO _x And the discharge amount of nitrogen oxides.

However, when all the burners included in the glass melting furnace are constituted by oxygen combustion burners, the concentration of moisture contained in the combustion exhaust gas tends to be high, and as a result, there is a problem that the amount of moisture contained in the molten glass also increases.

In particular, platinum members having good protection against molten glass are used in some glass manufacturing equipment. When moisture in the molten glass comes into contact with such platinum members, the moisture is decomposed, producing hydrogen gas and oxygen gas. Among them, hydrogen gas can permeate through the platinum member, and thus can rapidly escape to the outside of the system. However, oxygen remains directly in the molten glass, resulting in bubbles remaining in the manufactured glass article.

In order to cope with such a problem in quality of glass products caused by bubbles, patent document 1 proposes to dispose an oxygen combustion-supporting burner and an air combustion-supporting burner at predetermined positions to reduce the amount of water contained in molten glass.

However, in the structure of the glass melting furnace described in patent document 1, there is a problem that the efficiency of heat supplied into the glass melting furnace is poor and the amount of fuel used in the burner is significantly increased.

Further, according to the findings of the present inventors, when a burner arrangement as described in patent document 1 is adopted, there often occurs a problem that a glass product having a desired composition cannot be obtained.

The present application has been made in view of such a background, and an object of the present application is to provide a glass melting furnace capable of significantly improving thermal efficiency and obtaining molten glass in which variation in composition is significantly suppressed. In addition, the application also aims to provide a manufacturing device of the glass product with the glass melting furnace. The present application also provides a method for producing a glass product using such a glass melting furnace.

Means for solving the problems

In the present application, there is provided a glass melting furnace having an upstream wall and a downstream wall opposite to each other, and a first side wall and a second side wall opposite to each other,

a first burner group comprising an oxygen combustion-supporting burner and an air combustion-supporting burner is arranged on the first side wall, a second burner group comprising an oxygen combustion-supporting burner and an air combustion-supporting burner is arranged on the second side wall,

More than 70% of the total combustion heat per 1 hour supplied by the first burner group and the second burner group is supplied by the oxygen-supporting burner,

the first side wall and/or the second side wall has an exhaust port for exhausting combustion exhaust gas to the outside of the system, the exhaust port closest to the upstream wall is referred to as a specific exhaust port,

when the distance from the upstream wall to the downstream wall is L, the direction of L is referred to as the extending direction, and the burner located on the most upstream side in the first burner group is referred to as the first most upstream burner, the first most upstream burner is disposed at a position within 0.15L from the upstream wall along the extending direction,

the first most upstream burner is an air-assisted burner.

In addition, in the present invention, there is provided a glass product manufacturing apparatus, wherein the manufacturing device has:

a glass melting furnace,

Forming device

A conveying device connecting the glass melting furnace and the forming device,

the glass melting furnace is a glass melting furnace with the characteristics.

In addition, the present invention provides a method for producing a glass product, wherein the method comprises:

A melting step,

Conveying process

In the forming process, the forming step is carried out,

a glass melting furnace having the above-described characteristics is used in the melting process.

Effects of the invention

In the present invention, a glass melting furnace capable of significantly improving thermal efficiency and capable of obtaining molten glass with significantly suppressed variation in composition can be provided. In addition, in the present invention, a glass product manufacturing apparatus having such a glass melting furnace can be provided. In addition, the present invention can provide a method for producing a glass product using such a glass melting furnace.

Drawings

Fig. 1 is a schematic plan view of a glass melting furnace according to an embodiment of the present invention.

Fig. 2 is a schematic side sectional view of the glass melting furnace shown in fig. 1.

FIG. 3 is a schematic top view of another glass melting furnace according to one embodiment of the present invention.

Fig. 4 is a schematic side sectional view of the glass melting furnace shown in fig. 3.

Fig. 5 is a schematic top view of yet another glass melting furnace according to one embodiment of the present invention.

Fig. 6 is a schematic side cross-sectional view of the glass melting furnace shown in fig. 5.

Fig. 7 is a flowchart schematically showing a flow of a method for manufacturing a glass product according to an embodiment of the present invention.

Description of the reference numerals

1A-8A burner

1B-8B burner

100. Glass melting furnace (first melting furnace)

110. Upstream wall

112. Input port

120. Downstream wall

122. Extraction port

130A first sidewall

130B second side wall

140A first burner group

140B second burner group

150A first exhaust port

150B second exhaust port

160. Partition wall

192. Upper surface of

194. Bottom surface

200. Glass melting furnace (second melting furnace)

210. Upstream wall

212. Input port

220. Downstream wall

222. Extraction port

230A first side wall

230B second side wall

240A first burner group

240B second burner group

250A first exhaust port

250B second exhaust port

260. Partition wall

292. Upper surface of

294. Bottom surface

300. Glass melting furnace (third melting furnace)

310. Upstream wall

312. Input port

320. Downstream wall

322. Extraction port

330A first side wall

330B second side wall

340A first burner group

340B second burner group

350A first exhaust port

350B second exhaust port

380. Chamber chamber

382. Narrow passageway

392. Upper surface of

394. Bottom surface

BC melting part

MA glass raw material

MG-molten glass

PA first partition

PB second partition

UC ceiling part

Detailed Description

An embodiment of the present invention will be described below.

As described above, the structure of the glass melting furnace described in patent document 1 has problems in that the efficiency of heat supplied to the glass melting furnace is poor and the amount of fuel used is significantly increased. Further, when a burner arrangement as described in patent document 1 is adopted, there is a problem that a glass product having a desired composition is often not obtained.

In contrast, in one embodiment of the present invention, there is provided a glass melting furnace having upstream and downstream walls opposite to each other, and first and second side walls opposite to each other,

the first side wall and/or the second side wall has an exhaust port for exhausting combustion exhaust gas to the outside of the system, the exhaust port closest to the upstream wall being referred to as a specific exhaust port,

the first most upstream burner is an air-assisted burner.

The glass melting furnace according to one embodiment of the present application has an exhaust port for exhausting combustion exhaust gas to the outside of the system on the first side wall and/or the second side wall. The number of the exhaust ports provided on the first and second side walls is not particularly limited, and a plurality of exhaust ports may be present.

Here, among the exhaust ports provided in the first side wall and the second side wall, the exhaust port located at the position closest to the upstream wall is particularly referred to as "specific exhaust port" in the present application.

For example, in the case where the exhaust port exists only on the first side wall, the exhaust port located at the position closest to the upstream wall is referred to as a "specific exhaust port". Similarly, in the case where the exhaust port is present only on the second side wall, the exhaust port located at the position closest to the upstream wall is referred to as a "specific exhaust port".

Further, in the case where one or more exhaust ports are present on the first side wall and the second side wall, respectively, the exhaust port located at the position closest to the upstream wall is referred to as a "specific exhaust port". In this case, there may be two "specific exhaust ports".

In one embodiment of the application, more than 70% of the total combustion heat per 1 hour supplied by the first burner set and the second burner set is provided by the oxygen-fired burner.

Oxygen-fired burners generally have a higher combustion efficiency than air-fired burners. Accordingly, in the glass melting furnace according to the embodiment of the present application, the heat efficiency in the furnace can be remarkably improved by providing 70% or more of the total combustion heat per 1 hour by the oxygen combustion-supporting burner.

In addition, according to the findings of the present inventors, when the oxygen combustion-supporting burner is provided near the inlet of the glass raw material, the volatile components in the glass raw material are easily volatilized by the high heat supplied from the oxygen combustion-supporting burner.

However, in one embodiment of the present application, an air-assisted burner is used as the most upstream burner (first most upstream burner) in the first burner group. The first most upstream burner is disposed at a position within 0.15L from the upstream wall in the extending direction.

Compared with an oxygen combustion-supporting burner, the air combustion-supporting burner has low combustion efficiency. Therefore, in one embodiment of the present application, heat input to the glass raw material can be significantly suppressed. As a result, the volatile components contained in the glass raw material are not easily volatilized.

With such an effect, when the glass melting furnace according to one embodiment of the present application is used, the composition of molten glass can be made closer to a desired composition. In addition, a glass product having a desired composition can be produced.

According to the above effects, in one embodiment of the present application, a glass melting furnace capable of significantly improving thermal efficiency and capable of obtaining molten glass in which variation in composition is significantly suppressed can be provided.

Here, in the present application, the distance L from the upstream wall to the downstream wall is defined as the distance from the most downstream position of the upstream wall to the most upstream position of the downstream wall.

The distance L between the upstream wall and the first most upstream burner is defined as the distance from the position of the downstream most upstream wall to the first most upstream burner along the "extending direction".

(glass melting furnace according to one embodiment of the present invention)

Hereinafter, a glass melting furnace according to an embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

Fig. 1 is a schematic plan view of a glass melting furnace according to an embodiment of the present invention. Fig. 2 is a schematic side sectional view of a glass melting furnace according to an embodiment of the present invention.

As shown in fig. 1 and 2, a glass melting furnace (hereinafter referred to as a "first melting furnace" 100) of one embodiment of the present invention has an upstream wall 110 and a downstream wall 120 opposite to each other, and a first side wall 130A and a second side wall 130B opposite to each other.

An inlet 112 for glass raw material MA is provided in the upstream wall 110, and an outlet 122 for molten glass MG is provided in the downstream wall 120.

As described above, the distance between the upstream wall 110 and the downstream wall 120 is denoted by L, and the direction of the distance L is the "extending direction".

The first melting furnace 100 also has an upper surface 192 and a bottom surface 194. Accordingly, the upper ceiling UC is divided into the lower melting portion BC by the upper wall 110, the lower wall 120, the first side wall 130A, the second side wall 130B, the upper surface 192, and the bottom surface 194.

The melting portion BC accommodates the molten glass MG. A plurality of burners (described in detail below), a first exhaust port 150A, and a second exhaust port 150B are disposed on the ceiling UC.

A first burner group 140A including a plurality of burners 1A to 8A is disposed on the ceiling UC side of the first sidewall 130A. Similarly, a second burner group 140B including a plurality of burners 1B to 8B is disposed on the ceiling UC side of the second side wall 130B.

The burners 1A to 8A of the first burner group 140A and the burners 1B to 8B of the second burner group 140B have the function of injecting flames generated when the mixed gas is burned into the first melting furnace 100, respectively, to thereby melt the glass raw material MA and heat the molten glass MG.

In the first burner group 140A, the burner 1A is the most upstream-side burner, and thereafter, the reference numerals of the burners become larger in order as going toward the downstream side. Therefore, in the case where the first burner group 140A is configured of n (n is an integer of 2 or more) burners, the most downstream burner is denoted by a symbol nA. The same is true for each burner of the second burner group 140B.

The first exhaust port 150A is provided on the ceiling UC side of the first side wall 130A, and the second exhaust port 150B is provided on the ceiling UC side of the second side wall 130B. Each of the first exhaust port 150A and the second exhaust port 150B may be provided with 2 or more. In addition, one of the first exhaust port 150A and the second exhaust port 150B may be omitted.

The exhaust port closest to the upstream wall 110 among the first exhaust port 150A and the second exhaust port 150B is referred to as a "specific exhaust port". In the example shown in fig. 1 and 2, one each of the first exhaust port 150A and the second exhaust port 150B is provided. The first exhaust port 150A and the second exhaust port 150B are arranged at positions facing each other in a plan view. Therefore, in this case, both the first exhaust port 150A and the second exhaust port 150B are "specific exhaust ports".

Hereinafter, in the present application, in the first melting furnace 100, the upstream side of the specific exhaust port is referred to as "first Partition (PA)", and the downstream side of the specific exhaust port is referred to as "second Partition (PB)".

The respective burners 1A to 8A included in the first burner group 140A are divided into: burners 1A to 3A arranged in the "first partition PA" and burners 4A to 8A arranged in the "second partition PB". Similarly, the respective burners 1B to 8B included in the second burner group 140B are divided into: burners 1B to 3B arranged in the "first partition PA" and burners 4B to 8B arranged in the "second partition PB".

Referring again to fig. 1 and 2, the first melting furnace 100 has a partition wall 160 in the melting section BC. The partition wall 160 is disposed so as to extend parallel to the upstream wall 110 and the downstream wall 120. However, since the bottom of the partition wall 160 is open, the molten glass MG flows from the upstream side (upstream wall 110 side) to the downstream side (downstream wall 120 side) through the partition wall 160 along the extending direction (X direction in fig. 1 and 2) of the first melting furnace 100.

By providing such a partition wall 160, the molten glass MG in the melting portion BC can be homogenized. However, the partition wall 160 may be omitted.

The first melting furnace 100 of such a structure is used in the following manner.

First, glass raw material MA is supplied from inlet 112 of upstream wall 110 to melting section BC.

The glass raw material MA is heated by the flames of the respective burners 1A to 8A and 1B to 8B included in the first burner group 140A and the second burner group 140B, thereby forming the molten glass MG.

The molten glass MG is accommodated in the melting portion BC and flows downstream in the extending direction. The melting portion BC is provided with a partition wall 160. Accordingly, the molten glass MG flows in the downstream direction through the bottom of the partition wall 160. At this time, movement of "foreign matter" such as unmelted components, which may affect uniformity of the manufactured glass product, is hindered. Accordingly, the molten glass MG is homogenized by passing it through the partition wall 160.

Then, the molten glass MG reaching the downstream wall 120 is discharged from the take-out port 122 and conveyed to the next device of the glass manufacturing apparatus.

The combustion exhaust gas generated by the combustion of each of the burners 1A to 8A and 1B to 8B is discharged through the first exhaust port 150A and the second exhaust port 150B.

Here, in the first melting furnace 100, 70% or more of the total combustion heat per 1 hour supplied by the first burner group 140A and the second burner group 140B is supplied by the oxygen combustion-supporting burner. In other words, the contribution of the air-assisted burner is kept at most 30% of the total combustion heat.

By selecting the total combustion heat supplied from the oxygen combustion burner in this manner, the heat efficiency in the first melting furnace 100 can be significantly improved as compared with the conventional one.

In the first melting furnace 100, the first burner 1A located on the most upstream side in the first burner group 140A (hereinafter also referred to as "first most upstream burner 1A") is an air-assisted burner. The first most upstream burner 1A is disposed at a position of 0.15l or less from the upstream wall 110 along the extending direction of the first melting furnace 100.

When the first most upstream burner 1A is selected and arranged in this manner, as described above, the heat input to the glass raw material MA can be significantly suppressed. As a result, the volatile components contained in the glass raw material MA are not easily volatilized.

Therefore, in the first melting furnace 100, the composition of the molten glass can be made close to the desired composition. In addition, a glass product having a desired composition can be produced.

In the first melting furnace 100, the first burner 1B (hereinafter also referred to as "second most upstream burner 1B") located on the most upstream side in the second burner group 140B is also an air-assisted burner. The second most upstream burner 1B is disposed at a position of 0.15l or less from the upstream wall 110 along the extending direction of the first melting furnace 100.

In this case, volatilization of the volatile components contained in the glass raw material MA can be suppressed even further.

(description of the parts)

Next, each part of the glass melting furnace constituting one embodiment of the present invention will be described in more detail.

Here, for clarity, the first melting furnace 100 will be described below as an example. Accordingly, reference numerals shown in fig. 1 and 2 are used in the description of the respective parts.

(first melting furnace 100)

The first melting furnace 100 is applied as one device included in a glass manufacturing apparatus. Typically, glass manufacturing equipment has a glass melting furnace, a forming apparatus, and a conveyor connecting the two.

In the first melting furnace 100, a width between the first side wall 130A and the second side wall 130B is denoted by W (refer to fig. 1). Here, the width W is defined as a distance L from an innermost position of the first side wall 130A to an innermost position of the second side wall 130B.

In the first melting furnace 100, L/W is, for example, in the range of 2 to 5.

(first exhaust port 150A, second exhaust port 150B)

As described above, the exhaust port disposed on the most upstream side of the first exhaust port 150A and the second exhaust port 150B is referred to as a specific exhaust port. However, in the example shown in fig. 1 and 2, the first exhaust port 150A and the second exhaust port 150B are arranged at positions facing each other, and any one of the exhaust ports may be referred to as a specific exhaust port.

The specific exhaust port may be disposed at a position 0.3L to 0.7L from the upstream wall 110 along the extending direction of the first melting furnace 100.

In the case where there is one of the first exhaust port 150A and the second exhaust port 150B, the position of the second exhaust port 150B may be shifted from the first exhaust port 150A by 0L to 0.2L along the extending direction of the first melting furnace 100 in a plan view of the first melting furnace 100.

(first burner group 140A, second burner group 140B)

As described above, in the first melting furnace 100, 70% or more of the total combustion heat per 1 hour supplied from the first burner group 140A and the second burner group 140B is supplied from the oxygen-supporting burner.

In addition, 30 to 80% of the combustion heat per 1 hour in the first partition PA may be supplied from the oxygen-supporting burner.

On this basis or separately therefrom, 90% to 100% of the combustion heat per 1 hour in the second partition PB can be supplied by the oxygen-assisted burner.

In the example shown in fig. 1 and 2, in the first burner group 140A, the first most upstream burner 1A is disposed upstream of the specific exhaust port. Similarly, in the second burner group 140B, the second most upstream burner 1B is disposed on the upstream side of the specific exhaust port.

In such a configuration, the glass raw material MA charged into the first melting furnace 100 passes through the installation site of the specific vent after being melted to some extent. Therefore, the possibility that the glass raw material MA is discharged through a specific vent before melting can be significantly reduced. In particular, in the case where the glass raw material MA is discharged through the vent before melting, clogging of the vent or deviation in the composition of the produced glass product may often occur. However, in the structures shown in fig. 1 and 2, such problems can be reduced.

In the example shown in fig. 1, in a plan view of the first melting furnace 100, the burners 1A to 8A included in the first burner group 140A and the burners 1B to 8B included in the second burner group 140B are arranged so as to face each other. However, this is merely an example, and the relative positions of the respective burners 1A to 8A included in the first burner group 140A and the respective burners 1B to 8B included in the second burner group 140B are not particularly limited. For example, the burners 1A to 8A and the burners 1B to 8B may be arranged so as to be offset from each other in the extending direction of the first melting furnace 100.

The burners 1A to 8A included in the first burner group 140A are not necessarily arranged at equal intervals. For example, the burners 1A to 8A may be arranged at uneven intervals along the extending direction of the first melting furnace 100. The same is true for the second burner group 140B.

In addition, the number of burners included in the first burner group 140A and the second burner group 140B is not particularly limited. For example, the first burner group 140A and the second burner group 140B may include less than 8 or 9 or more burners, respectively.

In addition, in the first burner group 140A, the number of burners included in the first partition PA and the second partition PB is not particularly limited. The same applies to the second burner group 140B.

As described above, the first most upstream burner 1A in the first burner group 140A is arranged at a position within 0.15l from the upstream wall 110 along the extending direction of the first melting furnace 100. The distance is preferably 0.1L or less.

In addition, the second most upstream burner 1B in the second burner group 140B is preferably disposed at a position within 0.15l from the upstream wall 110 along the extending direction of the first melting furnace 100. Further, the distance is more preferably 0.1L or less.

(another glass melting furnace according to one embodiment of the present invention)

Next, another glass melting furnace according to an embodiment of the present invention will be described with reference to fig. 3 and 4.

Fig. 3 shows a schematic plan view of another glass melting furnace (hereinafter referred to as "second melting furnace") according to an embodiment of the present invention. In addition, fig. 4 shows a schematic side view of the second melting furnace shown in fig. 3.

As shown in fig. 3 and 4, the second melting furnace 200 has the same structure as the first melting furnace 100 described above. For example, the second melting furnace 200 includes an upstream wall 210, a downstream wall 220, a first sidewall 230A, a second sidewall 230B, a first burner group 240A, a second burner group 240B, and the like.

However, in general, the configuration of the first and second exhaust ports 250A and 250B of the second melting furnace 200 is different from that of the first melting furnace 100.

That is, in the second melting furnace 200, the first exhaust port 250A and the second exhaust port 250B are each arranged on the upstream side of the first burner group 240A and the second burner group 240B. The first exhaust port 250A and the second exhaust port 250B are disposed so as to face each other in a plan view of the second melting furnace 200. Thus, both the first exhaust port 250A and the second exhaust port 250B are "specific exhaust ports".

As a result of the above arrangement, in the second melting furnace 200, no burner is arranged on the upstream side of the specific exhaust port (for example, the first exhaust port 250A), that is, in the first partition PA, and all the burners are arranged on the downstream side of the specific exhaust port, that is, in the second partition PB.

Here, in the second melting furnace 200, 70% or more of the total combustion heat per 1 hour supplied from the first burner group 240A and the second burner group 240B is supplied from the oxygen-supporting burner.

In the second melting furnace 200, the first most upstream burner 1A in the first burner group 240A is an air-assisted burner, and the second most upstream burner 1B in the second burner group 240B is an air-assisted burner. When the distance from the upstream wall 210 to the downstream wall 220 is L, the first most upstream burner 1A in the first burner group 240A is disposed at a position of 0.15L or less from the upstream wall 210 in the extending direction of the second melting furnace 200.

In addition, as shown in fig. 3, the second most upstream burner 1B in the second burner group 240B may be arranged at a position of 0.15l or less from the upstream wall 210 along the extending direction of the second melting furnace 200.

It is apparent to those skilled in the art that the same effects as those of the first melting furnace 100 can be obtained in the second melting furnace 200 having such a structure.

That is, the heat efficiency in the second melting furnace 200 can be significantly improved even in the second melting furnace 200 as compared with the conventional one.

In addition, the heat input to the glass raw material MA can be significantly suppressed in the second melting furnace 200, and the volatile components contained in the glass raw material MA are less likely to volatilize. In addition, a glass product having a desired composition can be produced.

Next, another glass melting furnace according to an embodiment of the present invention will be described with reference to fig. 5 and 6.

A schematic top view of another glass melting furnace (hereinafter referred to as a "third melting furnace") of one embodiment of the present invention is shown in fig. 5. Fig. 6 is a schematic side view of the third melting furnace shown in fig. 5.

As shown in fig. 5 and 6, the third melting furnace 300 has the same structure as the first melting furnace 100. For example, the third melting furnace 300 includes an upstream wall 310, a downstream wall 320, a first side wall 330A, a second side wall 330B, a first burner group 340A, a second burner group 340B, and the like.

However, in general, the third melting furnace 300 is different from the first melting furnace 100 described above in that a chamber 380 is further provided on the downstream side of the downstream wall 320.

A narrow passageway 382 is disposed between the downstream wall 320 and the chamber 380. It should be noted that no burner is provided on the sidewall of the chamber 380.

By providing such a chamber 380, the temperature of the molten glass MG can be made uniform.

In the third melting furnace 300, the first burner group 340A has a total of 5 burners (first burner 1A to fifth burner 5A). Similarly, the second burner group 340B has a total of 5 burners (first burner 1B to fifth burner 5B).

In the third melting furnace 300, the first exhaust port 350A is disposed between the first burner 1A and the second burner 2A included in the first burner group 340A, and the second exhaust port 350B is disposed between the first burner 1B and the second burner 2B included in the second burner group 340B.

The first exhaust port 350A and the second exhaust port 350B are disposed so as to face each other in a plan view of the third melting furnace 300. Thus, both the first exhaust port 350A and the second exhaust port 350B are "specific exhaust ports".

As a result of the above arrangement, in the third melting furnace 300, only the first burner 1A (i.e., the first most upstream burner 1A) in the first burner group 340A is arranged on the upstream side of the specific exhaust port (e.g., the first exhaust port 350A), that is, in the first partition PA, and the second to fourth burners 2A to 4A are arranged on the downstream side of the specific exhaust port, that is, in the second partition PB. Similarly, in the second burner group 340B, only the first burner 1B (i.e., the second most upstream burner 1B) is disposed in the first partition PA, and the second to fourth burners 2B to 4B are disposed in the second partition PB.

Here, in the third melting furnace 300, 70% or more of the total combustion heat per 1 hour supplied from the first burner group 340A and the second burner group 340B is supplied from the oxygen-supporting burner.

In the first section PA, 30% to 80% of the combustion amount per 1 hour may be supplied from the oxygen-assisted burner. In the second zone PB, 90% to 100% of the combustion amount per 1 hour may be supplied from the oxygen combustion burner.

In the third melting furnace 300, the first most upstream burner 1A in the first burner group 340A is an air-assisted burner, and the second most upstream burner 1B in the second burner group 340B is an air-assisted burner. When the distance from the upstream wall 310 to the downstream wall 320 is L, the first most upstream burner 1A in the first burner group 340A is disposed at a position of 0.15L or less from the upstream wall 310 in the extending direction of the third melting furnace 300.

In addition, as shown in fig. 5, the second most upstream burner 1B in the second burner group 340B may be arranged at a position of 0.15l or less from the upstream wall 310 along the extending direction of the third melting furnace 300.

It is apparent to those skilled in the art that the same effects as those of the first melting furnace 100 and the second melting furnace 200 can be obtained in the third melting furnace 300 having such a structure.

That is, even in the third melting furnace 300, the heat efficiency in the third melting furnace 300 can be significantly improved as compared with the conventional one.

In addition, in the third melting furnace 300, heat input to the glass raw material MA is also significantly suppressed, and the volatile components contained in the glass raw material MA are not easily volatilized. In addition, a glass product having a desired composition can be produced.

In the above, the glass melting furnaces according to the embodiment of the present application are described by taking the first to third melting furnaces 100 to 300 as an example. However, the glass melting furnace according to one embodiment of the present application is not limited to the above embodiment. In addition to this, various embodiments will be apparent to those skilled in the art.

For example, in the first to third melting furnaces 100 to 300, the first burner 1A in the first burner group is selected as an air-assist burner in order to suppress volatilization of the volatile components contained in the glass raw material MA.

However, in the glass melting furnace according to the embodiment of the present application, a small auxiliary oxygen combustion-supporting burner or the like may be provided upstream of the first burner 1A as long as volatilization of volatile components can be suppressed.

In other words, in the present application, the terms "first burner", "first most upstream burner", "second most upstream burner" do not exclude the presence of an "auxiliary" burner upstream thereof, as long as the effects of the present application are exerted.

(method for producing glass article according to one embodiment of the invention)

Next, a method for manufacturing a glass product according to an embodiment of the present invention will be described with reference to fig. 7.

Fig. 7 schematically shows a flow of a method for manufacturing a glass product according to an embodiment of the present invention.

As shown in fig. 7, a method for manufacturing a glass product according to an embodiment of the present invention (hereinafter referred to as "first method") includes:

a melting step (step S110) of melting a glass raw material to form molten glass;

a conveying step (step S120) of conveying molten glass; and

a molding step (step S130) of molding the molten glass.

Hereinafter, each step will be described.

(Process S110)

First, a glass raw material is melted using a glass melting furnace, thereby forming molten glass. The composition of the glass raw material is not particularly limited.

The glass melting furnace according to one embodiment of the present invention is used as a glass melting furnace. For example, glass melting furnaces such as the first to third melting furnaces 100 to 300 described above may be used.

For example, when the first melting furnace 100 is used as the glass melting furnace, the glass raw material MA supplied from the inlet 112 of the upstream wall 110 is heated by the flames of the burners 1A to 8A included in the first burner group 140A and the burners 1B to 8B included in the second burner group 140B. Thereby forming molten glass MG. The molten glass thus formed is discharged from the discharge port 122.

In the case of using the glass melting furnace according to the embodiment of the present invention as the glass melting furnace, 70% or more of the total combustion heat per 1 hour supplied from the first burner group and the second burner group is supplied from the oxygen combustion-supporting burner. Therefore, the thermal efficiency in the glass melting furnace can be significantly improved.

In addition, when the glass melting furnace according to the embodiment of the present invention is used, the heat input of the glass raw material MA on the side of the inlet 112 can be significantly suppressed, and thus the volatilization of the volatile components in the glass raw material MA can be significantly suppressed. In addition, as a result, the composition of the molten glass can be made closer to the desired composition, and a glass product having the desired composition can be produced.

(Process S120)

The formed molten glass is then conveyed to a forming apparatus by a conveying apparatus.

(Process S130)

The conveyed molten glass is then formed in a forming apparatus. Thereby forming a glass ribbon. In addition, the glass ribbon is slowly cooled, thereby manufacturing a glass article. The glass article may be cut to the desired size, if desired.

The glass article produced may be an alkali-free glass.

The alkali-free glass may contain, in mass% on an oxide basis:

SiO ₂ ：54％～73％、

Al ₂ O ₃ ：10％～23％、

B ₂ O ₃ ：0.1％～12％、

MgO：0～12％、

CaO：0～15％、

SrO:0 to 16%, and

BaO：0～15％，

MgO+CaO+SrO+BaO：8％～26％。

in the case of alkali-free glasses of such composition, B ₂ O ₃ Corresponding to volatile components.

In addition, the beta-OH of the glass product produced can be in the range of 0.3mm ^-1 ～0.45mm ^-1 Within a range of (2).

Here, β—oh is an index indicating the amount of moisture in the glass, and a larger value indicates a larger amount of moisture in the glass.

Examples

Hereinafter, examples of the present invention will be described. In the following description, examples 1 to 3 are examples, and examples 11 to 15 are comparative examples.

Example 1

The glass raw material is melted using a glass melting furnace such as the first melting furnace 100 described above.

The glass raw material is alkali-free glass having the following composition in mass% based on oxide;

SiO ₂ ：54％～73％、

Al ₂ O ₃ ：10％～23％、

B ₂ O ₃ ：0.1％～12％、

MgO：0～12％、

CaO：0～15％、

SrO:0 to 16%, and

BaO：0～15％。

mgo+cao+sro+bao=8% to 26%.

Wherein B is ₂ O ₃ Is a relatively volatile component.

In the glass melting furnace, the first burner group and the second burner group are each composed of 8 burners in total.

In addition, a first exhaust port is provided in the first side wall, and a second exhaust port is provided in the second side wall. The first exhaust port and the second exhaust port are arranged at positions opposed to each other in a plan view. Thus, both the first exhaust port and the second exhaust port are specific exhaust ports.

The first exhaust port and the second exhaust port are provided at positions 0.55L from the upstream wall along the extending direction of the glass melting furnace.

As shown in fig. 1 and 2, the number of burners arranged in the first partition PA is 6, i.e., 1A to 3A and 1B to 3B, and the number of burners arranged in the second partition PB is 10, i.e., 4A to 8A and 4B to 8B.

In the first burner group, only the most upstream first burner 1A is set as an air-assisted burner. In the second burner group, only the most upstream second burner 1B is set as the air-assisted burner. The remaining burner is set as an oxygen-fired burner.

The distance between the upstream wall along the extending direction of the glass melting furnace and the most upstream air-assisted burner (burner 1A) in the first burner group was set to 0.1L. In addition, the distance between the upstream wall along the extending direction of the glass melting furnace and the most upstream air-assisted burner (burner 1B) in the second burner group was set to 0.1L.

The contribution of the oxygen-fired burner to the total heat supplied was 88%. In the first partition PA, the contribution ratio of the oxygen-assisted burner to the supplied heat was 71%. The contribution rate of the oxygen-fired burner in the second partition PB to the supplied heat is 100%.

Example 2

The glass raw material was melted using the same glass melting furnace as in example 1.

However, in this example 2, the first burner 1A and the eighth burner 8A in the first burner group are set as air-assisted burners. Similarly, the first burner 1B and the eighth burner 8B in the second burner group are set as air-assisted burners. The remaining burner is set as an oxygen-fired burner.

The contribution of the oxygen-fired burner to the total heat supplied was 82%. In the first partition PA, the contribution ratio of the oxygen-assisted burner to the supplied heat was 71%. The contribution rate of the oxygen-fired burner to the supplied heat in the second partition PB is 90%.

Example 3

However, in this example 3, the first burner 1A and the second burner 2A in the first burner group are set as air-assisted burners. Similarly, the first burner 1B and the second burner 2B in the second burner group are set as air-assisted burners. The remaining burner is set as an oxygen-fired burner.

The contribution of the oxygen-fired burner to the total heat supplied was 73%. In the first partition PA, the contribution ratio of the oxygen-assisted burner to the supplied heat was 36%. The contribution rate of the oxygen-fired burner in the second partition PB to the supplied heat is 100%.

Example 11

However, in this example 11, all of the burners included in the first burner group were oxygen-assisted burners. Similarly, all of the burners included in the second burner group are set as oxygen-assisted burners.

The contribution of the oxygen-fired burner to the total heat supplied was 100%. In the first partition PA, the contribution ratio of the oxygen-assisted burner to the supplied heat is 100%. Similarly, the contribution of the oxygen-fired burner in the second partition PB to the supplied heat is 100%.

Example 12

However, in this example 12, the third burner 3A in the first burner group is set as an air-assisted burner. Similarly, in the second burner group, the third burner 3B is set as an air-assisted burner. The remaining burner is set as an oxygen-fired burner.

The distance between the upstream wall along the extending direction of the glass melting furnace and the most upstream air-assisted burner (burner 3A) in the first burner group was 0.25L. Likewise, the distance between the upstream wall along the extending direction of the glass melting furnace and the most upstream air-assisted burner (burner 3B) in the second burner group was 0.25L.

The contribution of the oxygen-fired burner to the total heat supplied was 85%. In addition, the contribution rate of the oxygen-supporting burner to the supplied heat in the first partition PA was 71%. The contribution rate of the oxygen-fired burner in the second partition PB to the supplied heat is 100%.

Example 13

However, in this example 13, the eighth burner 8A in the first burner group is set as an air-assisted burner. Similarly, in the second burner group, the eighth burner 8B is set as an air-assisted burner. The remaining burner is set as an oxygen-fired burner.

The distance between the upstream wall along the extending direction of the glass melting furnace and the most upstream air-assisted burner (burner 8A) in the first burner group was 0.9L. Likewise, the distance between the upstream wall along the extending direction of the glass melting furnace and the most upstream air-assisted burner (burner 8B) in the second burner group was 0.9L.

The contribution of the oxygen-fired burner to the total heat supplied was 94%. In addition, the contribution rate of the oxygen-supporting burner to the supplied heat in the first partition PA is 100%. The contribution rate of the oxygen-fired burner to the supplied heat in the second partition PB is 90%.

Example 14

However, in this example 14, the first burner 1A and the fifth to eighth burners 5A to 8A in the first burner group are set as air-assisted burners. Similarly, the first burner 1B and the fifth to eighth burners 5B to 8B in the second burner group are set as air-assisted burners. The remaining burner is set as an oxygen-fired burner.

The distance between the most upstream air-assisted burner (burner 1A) and the upstream wall in the first burner group along the extending direction of the glass melting furnace was 0.1L. In addition, the distance between the most upstream air-assisted burner (burner 1B) and the upstream wall in the second burner group along the extending direction of the glass melting furnace was 0.1L.

The contribution of the oxygen-fired burner to the total heat supplied was 44%. In addition, the contribution rate of the oxygen-supporting burner to the supplied heat in the first partition PA was 71%. The contribution rate of the oxygen-fired burner to the supplied heat in the second partition PB is 24%.

Example 15

However, in this example 15, the first to second burners 1A to 2A and the fifth to eighth burners 5A to 8A in the first burner group were set as air-assisted burners. Similarly, the first to eighth burners 1B to 2B and 5B to 8B in the second burner group are set as air-assisted burners. The remaining burner is set as an oxygen-fired burner.

The contribution of the oxygen-fired burner to the total heat supplied was 29%. In addition, the contribution rate of the oxygen-supporting burner to the supplied heat in the first partition PA was 36%. The contribution rate of the oxygen-fired burner to the supplied heat in the second partition PB is 24%.

Table 1 below shows the structure of the burner of the glass melting furnace used in each example.

(evaluation)

In each example, the fuel usage amount per 1 hour in the operation of the glass melting furnace was evaluated. In each example, the ease of volatilization of the volatile components in the molten glass was evaluated. Further, β -OH in the molten glass obtained in each example was evaluated.

The volatile component volatility was evaluated as follows.

The surface temperature of the molten glass was measured near the tip of the flame of the first burner 1A in the first burner group. When the surface temperature is higher than 1650 ℃, it is determined that the volatile component is easily volatilized, and when the surface temperature is 1650 ℃ or lower, it is determined that the volatile component is hardly volatilized. A two-color radiation thermometer was used for the temperature measurement.

In addition, β -OH was evaluated in the following manner.

First, the moisture concentration and the like contained in the gas after combustion are calculated from the composition and the like of the fuel and the gas combusted by each burner. Next, the distribution of the moisture concentration in the atmosphere in the melting chamber is calculated in consideration of the flow of the burned gas to the first exhaust port and the second exhaust port. Then, the amount of water finally diffused into the molten glass is calculated from the distribution of the water concentration and the average flow rate of the molten glass, and converted into β -OH contained in the glass after production.

The results obtained in each example are summarized in table 2 below.

TABLE 2

In table 2, the column "fuel usage" indicates the standard value of the fuel usage in example 11. That is, the fuel usage amount in example 11 was set to 100, and the "fuel usage amount" in each example was expressed as a ratio with respect to the fuel usage amount.

In table 2, the "evaporation suppression effect" is indicated by "o" indicating that the volatile component is not easily evaporated, and by "x" indicating that the volatile component is easily evaporated.

From the obtained results, it was found that in example 11 in which all the burners were set as oxygen-assisted burners, the fuel consumption was suppressed to be low. However, it can be seen that in example 11, the β -OH in the glass is highest. In example 11, it can be seen that the volatile components in the glass raw material are easily volatilized.

In addition, it was found that in examples 12 to 13, the volatile components in the glass raw materials were easily volatilized.

In examples 14 to 15, the volatilization of the volatile components tended to be suppressed, but the fuel usage amount increased, and the efficiency decreased.

On the other hand, it can be seen that in examples 1 to 3, volatilization of volatile components hardly occurs. In examples 1 to 3, the fuel consumption was also significantly suppressed. In examples 1 to 3, β -OH was also significantly suppressed.

It was confirmed that by setting the contribution ratio of the oxygen combustion burner to the total combustion heat to 70% or more in this way, the thermal efficiency can be significantly improved. It was also confirmed that the volatilization of the volatile components can be significantly suppressed by setting the first and second most upstream burners 1A, 1B as air-assisted burners and the distance from the upstream wall to these burners 1A, 1B along the extending direction to 0.15L or less.

Claims

1. A glass melting furnace, wherein the glass melting furnace has an upstream wall and a downstream wall opposite to each other, and a first side wall and a second side wall opposite to each other,

a first burner group comprising an oxygen-assisted burner and an air-assisted burner is arranged on the first side wall, a second burner group comprising an oxygen-assisted burner and an air-assisted burner is arranged on the second side wall,

More than 70% of the total combustion heat per 1 hour supplied by the first burner group and the second burner group is supplied by the oxygen-assisted burner,

the first most upstream burner is an air-assisted burner.

2. The glass melting furnace of claim 1, wherein the first most upstream burner is disposed upstream of the particular vent.

3. The glass melting furnace according to claim 1 or 2, wherein when a burner located on the most upstream side in the second burner group is referred to as a second most upstream burner, the second most upstream burner is disposed at a position within 0.15L from the upstream wall in the extending direction,

The second most upstream burner is an air-assisted burner.

4. The glass melting furnace of claim 3, wherein the second most upstream burner is disposed upstream of the particular exhaust port.

5. The glass melting furnace according to any one of claims 1 to 4, wherein the specific vent is arranged at a position 0.3L to 0.7L from the upstream wall along the extending direction.

6. The glass melting furnace according to any one of claims 1 to 5, wherein,

the first side wall is provided with 1 or more than 2 first exhaust ports,

and more than 1 or 2 second exhaust ports are arranged on the second side wall.

7. The glass melting furnace according to claim 6, wherein,

one for each of the first and second exhaust ports,

the second exhaust port is arranged at a position offset from the first exhaust port by 0L to 0.2L in the extending direction.

8. The glass melting furnace according to any one of claims 1 to 7, wherein L/w=2 to 5 when a distance between the first side wall and the second side wall is set to a width W.

9. The glass melting furnace according to any one of claims 1 to 8, wherein a partition wall for guiding molten glass is provided between the upstream wall and the downstream wall,

The molten glass flows at the bottom of the glass melting furnace while passing through the partition wall.

10. A manufacturing apparatus that is a manufacturing device for glass products, wherein the manufacturing apparatus has:

a glass melting furnace,

Forming device

A conveying device connecting the glass melting furnace and the forming device,

the glass melting furnace is the glass melting furnace according to any one of claims 1 to 9.

11. A manufacturing method, which is a manufacturing method of a glass product, wherein the manufacturing method has:

a melting step,

Conveying process

In the forming process, the forming step is carried out,

the glass melting furnace according to any one of claims 1 to 9 is used in the melting step.

12. The manufacturing method according to claim 11, wherein,

the glass article is comprised of alkali-free glass,

the alkali-free glass contains, in mass% based on oxides:

SiO ₂ ：54％～73％、

Al ₂ O ₃ ：10％～23％、

B ₂ O ₃ ：0.1％～12％、

MgO：0～12％、

CaO：0～15％、

SrO:0 to 16%, and

BaO:0 to 15 percent, and

MgO+CaO+SrO+BaO accounts for 8 to 26 percent.

13. The method of manufacturing of claim 11 or 12, wherein the glass article has a beta-OH of 0.3mm ^-1 ～0.45mm ^-1 Within a range of (2).