TWI480238B - Production method and manufacturing apparatus of floating glass - Google Patents

Description

Floating glass manufacturing method and manufacturing device

The present invention relates to a method and apparatus for producing a floating glass, and more particularly to a method and apparatus for producing a floating glass in which a protective film for preventing flaws is formed in a slow cooling furnace.

As shown in Fig. 4, the floating glass is formed into a strip glass 44 having a desired thickness and width by supplying molten glass to the molten tin 43 of the float bath 42. The formed strip glass 44 is lifted from the exit of the float bath 42 by the pinch roller 48 of the pinch portion 45 provided adjacent to the float bath 42, and then cooled and cooled in the slow cooling furnace 46 to become a glass ribbon ( Floating glass) 41. Further, the glass ribbon 41 is further cooled to a room temperature which can be cut in the cooling annealing furnace 47, and is cut into a predetermined size by the cutting device 53. During this period, the glass ribbon 41 is pulled and conveyed by the transport roller 51, whereby it can be continuously manufactured.

It is known that in the above-described floating glass manufacturing step, in order to prevent the occurrence of flaws caused by the conveyance roller 51 or the subsequent conveyance or the occurrence of flaws during conveyance, the surface of the formed glass ribbon 41 is sprayed. Sulfuric acid gas (SO ₂ ) forms a protective coating of sulfate. For example, Patent Document 1 discloses that, as shown in FIG. 4, a nozzle 54 for spraying sulfurous acid gas is provided in an upstream region of the slow cooling furnace 46, and the nozzle 54 is moved from the nozzle 54 to the slow cooling furnace 46. The glass ribbon 41 during the conveyance of the conveyance roller 51 is sprayed with sulfurous acid gas to form a protective film. In the high-temperature slow cooling furnace 46, the sulfurous acid gas sprayed on the glass ribbon 41 reacts with the constituent components of the glass to form a protective film of sulfate such as sodium sulfate on the surface of the glass ribbon 41. The protective coating of the sulfate is finally removed by washing.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] International Publication No. 02/051767

When a protective coating of sulfate is formed in the slow cooling furnace of the floating glass manufacturing apparatus, sulfurous acid gas is sprayed upstream of the slow cooling furnace having a higher temperature. In Patent Document 1, a nozzle is provided in a region partitioned by a partition wall upstream of a slow cooling furnace, and sulfite gas is sprayed thereon, thereby increasing the concentration of sulfurous acid gas in the region and improving the reaction efficiency with glass. Thereby, the protective film is efficiently formed on the surface of the glass ribbon. However, even if sulfite gas is sprayed in the area partitioned by the partition wall, the remaining sulfurous acid gas will flow out to the slow cooling furnace in a large range, and the sulfurous acid gas is retained in the slow cooling furnace or the self-slow cooling furnace. Then leak to the outside.

The remaining sulfurous acid gas in the cooling furnace will corrode the structure of the slow cooling furnace or flow into the intervening portion adjacent to the slow cooling furnace from the gap of the conveying roller, thereby corroding the structure of the pinching portion in the same manner. And causing a large loss, not only that the rust or corrosive material on the corroded structure will fall onto the surface of the glass ribbon, or may adhere or fix on the surface of the roller, thereby causing foreign matter adhesion on the surface of the glass ribbon. Or defects such as defects, resulting in a decrease in the quality of the obtained float glass and a decrease in yield.

Therefore, in Patent Document 1, there is a description of the case where the sulfurous acid gas is self-sealing when a protective film is formed by spraying sulfurous acid gas in a sealed cooling annealing furnace (sealed lehr). The cooling annealing furnace flows into the floating bath to contaminate the molten tin in the floating bath, and a suction nozzle is disposed adjacent to the nozzle to suction the unused unused portion of the sprayed sulfurous acid gas to form a protective film of the glass ribbon The sulphurous acid gas is discharged to the outside of the system. However, in such a method, it is difficult to solve the above problems in the slow cooling furnace.

The present invention has been made in view of the above problems, and an object thereof is to provide a protective film having a sufficient thickness on a surface of a glass ribbon, and capable of reducing or preventing leakage of sulfurous acid gas from the inside of the slow cooling furnace to the outside. And a manufacturing method and a manufacturing apparatus of the floating glass which corrode the structure of a cooling furnace.

The present invention has been made in an effort to achieve the above object. The present invention provides a method for producing a floating glass, which comprises a glass ribbon which has been formed in a floating bath and lifted from the floating bath by the pinching portion. a step of transporting the glass ribbon to a slow cooling furnace having a temperature below the strain point temperature of the glass. In the method for producing a floating glass, the nozzle provided in the upstream portion of the slow cooling furnace is directed to the slow cooling furnace. The sulfite gas is supplied to the lower surface of the glass ribbon during the transport, and the exhaust chamber is provided in a region downstream of the position where the nozzle is provided to suck the environment in the slow cooling furnace. The gas stream of the sulfite gas is formed around the glass ribbon in the direction in which the glass ribbon is conveyed, and the gas stream is guided to the exhaust chamber to discharge the remaining sulfurous acid gas to the outside.

Preferably, an air supply chamber is disposed on a downstream side of the exhaust chamber, and external air is supplied from the air supply chamber to the glass ribbon, thereby forming a positive relationship with respect to the outside of the exhaust chamber. The environment of pressure.

Preferably, the rotational speed of the exhaust fan provided in the exhaust pipe connected to the exhaust chamber and/or the opening degree of the damper provided in the exhaust pipe are controlled to adjust the exhaust amount.

Preferably, the rotational speed of the air supply fan provided in the air supply pipe connected to the air supply chamber and/or the opening degree of the damper provided in the air supply pipe are controlled to adjust the air supply amount.

Preferably, the inside of the slow cooling furnace and the exhaust chamber are maintained at a temperature equal to or higher than an acid dew point of the sulfite gas.

Moreover, the present invention provides a floating glass manufacturing apparatus which has a slow cooling furnace in which a glass ribbon which has been formed in a floating bath and which is lifted from the floating bath by the pinching portion is slowly cooled to a temperature lower than a strain point temperature of the glass. In the floating glass manufacturing apparatus, a nozzle is provided in an upstream portion of the slow cooling furnace, and the nozzle sprays sulfurous acid gas on a lower surface of the glass ribbon during transport by the transfer roller in the slow cooling furnace. Further, in a region downstream of the position where the nozzle is provided, an exhaust chamber for sucking the environment in the slow cooling furnace is provided above the glass ribbon.

Preferably, on the downstream side of the exhaust chamber, an air supply chamber for supplying external air to the glass ribbon and forming an environment of positive pressure with respect to the outside behind the exhaust chamber is provided.

Preferably, a separator is provided above and/or below the glass ribbon during the transport in the slow cooling furnace on the downstream side of the exhaust chamber.

Preferably, the structure exposed to the environment above the glass ribbon during the transport in the slow cooling furnace is formed of an acid-resistant incombustible material.

Preferably, a scrubber that communicates with the exhaust pipe for exhausting the sulfurous acid gas is provided at a front end of the exhaust pipe that communicates with the exhaust chamber.

According to the present invention, since a gas stream containing an environment containing sulfurous acid gas is formed around the glass ribbon in the direction in which the glass ribbon is conveyed, a protective film can be formed by the sulfurous acid gas carried in the gas stream. As a result, in particular, the protective film can be efficiently formed on the lower surface of the glass ribbon, and therefore, generation of flaws due to the conveyance roller can be prevented. Further, it is possible to reduce or prevent the leakage of the sulfurous acid gas from the inside of the slow cooling furnace to the outside and the corrosion of the structure of the cooling furnace.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification, the lower surface of the glass ribbon refers to the surface on the side where the glass ribbon contacts the conveying roller, and the lower surface refers to the direction in which the lower surface faces, and the upper side of the glass ribbon refers to the opposite of the lower surface. The direction in which the side surface (upper surface) faces.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal sectional explanatory view of a floating glass manufacturing apparatus according to a preferred embodiment of the present invention, and Fig. 2 is a plan view of a portion A-A. Only one half of the slow cooling furnace is illustrated in Fig. 2, but one half of the cooling furnace is also symmetrical and identical. As shown in the figure, the glass ribbon 1 formed into the ribbon glass 4 on the molten tin 3 of the float bath 2 is self-molded from the molten tin 3 by the pinch roller 8 provided in the pinch portion 5 of the outlet of the float bath 2. It is lifted up and transferred to the slow cooling furnace 6 provided continuously in the pinching part 5. In the pinch portion 5, the pinch roller 8 is disposed at a higher level than the molten tin surface of the float bath 2. In the floating bath 2, the glass ribbon 1 formed into the strip glass 4 is lifted by the pinch roller 8, and then cooled in the pinch portion 5 having the surrounding structure 9 until it is in a stable state, and is transported to the slow cooling furnace. 6.

The slow cooling furnace 6 is a device having an adjustable temperature surrounding the structure 10 in the same manner as a slow cooling furnace commonly used in the manufacture of a plurality of glass products, and a plurality of conveying rollers 11 are arranged side by side inside. The conveyance rollers 11 are driven at a constant speed by a drive motor (not shown), and the belt-shaped glass ribbon 1 is pulled or conveyed at a predetermined constant speed. In this case, a part of the conveying roller can be rotatably driven without being drivenly coupled to the driving motor. The slow cooling furnace 6 has a length of several tens of meters, and the temperature inside the slow cooling furnace 6 having the surrounding structure 10 is subjected to temperature management to obtain a temperature from the upstream portion (for example, about 600 to 750 ° C) to the end temperature of the downstream portion. (for example, about 200 to 400 ° C) temperature distribution. Thereby, the glass ribbon 1 is gradually cooled to a temperature equal to or lower than the strain point temperature of the glass during the conveyance by the transfer roller 11 in the slow cooling furnace 6, so that non-ideal thermal stress does not remain in the glass. Moreover, usually, when reaching the exit of the slow cooling furnace 6, the glass ribbon 1 is cooled to a temperature lower than the strain point temperature of the glass. The glass ribbon 1 cooled in the slow cooling step of the slow cooling furnace 6 has a high temperature of about 200 to 400 ° C at the outlet of the slow cooling furnace 6 as described above, and thus is cooled in the cooling annealing furnace 7 to be cut off. After the temperature, the cutting device 13 is cut into a predetermined size. The cooling annealing furnace 7 may not have a temperature that surrounds the structure 10 as in the slow cooling furnace 6 as long as the slowly cooled glass ribbon can be cooled to near room temperature.

As shown in Fig. 1, the nozzle 14 for spraying sulfite gas to the lower surface of the glass ribbon 1 is provided at the upstream portion of the slow cooling furnace 6, and further, at the position where the nozzle 14 is provided (the spray of sulfurous acid gas) The downstream portion of the attached position is provided with the exhaust chamber 12 to suck the environment in the slow cooling furnace 6, whereby the sulfurous acid gas in the upstream portion is transported along the glass ribbon 1 into the airflow containing the environment of the sulfurous acid gas. The direction is formed around the glass ribbon 1, and is guided to the exhaust chamber 12 and discharged to the outside from the exhaust chamber 12. Thereby, in the slow cooling step of the slow cooling furnace 6, the nozzle 14 is used to spray sulfite gas to the lower surface of the glass ribbon 1 at a high temperature in the upstream portion, thereby forming a protective layer for preventing the sulphate containing sulphate (protection) By coating the film, it is possible to prevent the occurrence of defects caused by the conveyance roller or the occurrence of flaws during transportation or transportation.

In the present invention, the nozzle 14 is provided in the upstream portion of the slow cooling furnace 6, whereby the sulfurous acid gas is sprayed on the lower surface of the glass ribbon 1 having a high temperature, whereby the protective film can be preferably formed. The higher the temperature, the easier the surface of the lower surface of the glass ribbon 1 to form a protective film comprising sulfate derived from sulfurous acid gas. In the present invention, the upstream portion of the slow cooling furnace 6 is thus subjected to high temperature management. The temperature of the glass ribbon 1 suitable for forming the protective film varies depending on the type of the glass, etc., but is preferably 500 to 750 ° C, more preferably 600 to 750 ° C.

As the gas used for forming the protective film, sulfurous acid gas is preferred. The sulfite gas reacts with the chemical components in the glass to form a coating of a sulfate such as sodium sulfate on the surface of the glass ribbon 1, and the coating is easily removed by washing with water. Sulfurous acid gas is usually used alone, but may contain other gases as needed. When the sulfurous acid gas is sprayed onto the glass ribbon 1 at the upstream portion of the slow cooling furnace 6, in order to cool the glass ribbon at a temperature above the strain point without impairing the slow cooling treatment, the sulfurous acid gas is preferably pre-treated. Heat to, for example, around 400~600 °C.

In the present invention, the exhaust chamber 12 is provided in a region downstream of the position where the nozzle 14 is provided. FIG. 1 is an example in which the exhaust chamber 12 is provided at a downstream portion of the slow cooling furnace 6. In the upstream portion of the slow cooling furnace 6, most of the sulfurous acid gas sprayed from the nozzle 14 onto the glass ribbon 1 reacts with the glass component of the glass ribbon 1, so that the coating of the sulfate is formed on the lower surface of the glass ribbon 1. The remaining sulfurous acid gas is contained in the furnace environment upstream of the slow cooling furnace 6. The exhaust chamber 12 has a function of sucking an environment containing sulfurous acid gas in the furnace in the upstream portion in the downstream direction, thereby forming a sulfurous acid containing the sulfuric acid around the glass ribbon 1 in the direction in which the glass ribbon 1 is conveyed. The gas flow in the environment of the gas causes the stagnant state of the sulfurous acid gas to not be generated in the slow cooling furnace 6, and the protective film is formed by the air flow of the environment containing sulfurous acid gas formed around the glass ribbon 1, Further, the remaining sulfurous acid gas is discharged to the outside. If the exhaust chamber 12 is provided at the end (downstream end) of the slow cooling furnace 6, the airflow containing the environment of the sulfurous acid gas is guided to the end of the slow cooling furnace 6 and discharged through the exhaust chamber 12. Therefore, it is possible to prevent a part of the airflow from flowing toward the back (downstream side) of the exhaust chamber 12. However, the position of the exhaust chamber 12 may be a region downstream of the gas spraying position, or may be a flow portion or a downstream portion of the cooling furnace 6. Preferably, however, it is disposed in a glass temperature region (less than 500 ° C) which is lower than the temperature of the glass ribbon suitable for forming the protective film.

The inside of the exhaust chamber 12 has a cylindrical structure 27 for efficiently sucking an environment containing sulfurous acid gas in the slow cooling furnace 6, and an environment for sucking in the upper portion of the cylindrical structure 27 The exhaust pipe 15 is discharged to the outside. The exhaust pipe 15 is in communication with the exhaust chamber 12. The shape of the cylindrical structure 27 is not specific, but in order to uniformly suck the entire width direction of the cooling furnace 6 in the environment in the cooling furnace 6, as shown in Fig. 2, the cross-sectional shape is a rectangle. The shape of both sides is preferably equal to or greater than the width of the glass ribbon, and more preferably the outer portion of the transfer roller 11 protrudes outward. The width a of the tubular structure 27 is mainly determined by the amount of the furnace of the slow cooling furnace 6, and its size is preferably 0.5 to 4 m. If a has such a size, it can be slowly sucked without affecting the slow cooling operation in the environment within the slow cooling furnace 6. If a is too small, pressure loss will occur, so it is not ideal. Further, in the environment in the slow cooling furnace 6, in order to perform suction at a position relatively close to the glass ribbon 1, an atmosphere containing a sulfurous acid gas is formed as close as possible to the vicinity of the glass ribbon 1, preferably as a cylinder. The lower end of the structure 27 is spaced apart from the glass ribbon 1 by a predetermined interval (preferably 10 to 100 mm, more preferably 10 to 50 mm). At this time, it is preferable that the lower end of the upstream side of the cylindrical structure 27 is farther away from the glass ribbon than the lower end of the downstream side, and particularly preferably a distance of 20 to 70 mm.

The exhaust of the exhaust chamber 12 is realized by driving the exhaust fan 17 provided in the exhaust pipe 15 by the drive motor 18. A damper 16 may also be provided in the exhaust pipe 15 to adjust the amount of exhaust of the exhaust chamber 12. When the damper 16 is provided in the exhaust pipe 15 as described above, the amount of exhaust of the exhaust chamber 12 can be adjusted by controlling the rotational speed of the exhaust fan 17 and/or the opening degree of the damper 16. The amount of exhaust of the exhaust chamber 12 is adjusted in consideration of the amount of spraying of the sulfurous acid gas of the nozzle 14, and the like.

In the slow cooling furnace 6 shown in FIG. 1, as an example in which the exhaust chamber 12 is provided at the end of the slow cooling furnace 6, the exhaust chamber 12 is provided inside the slow cooling furnace 6. Although the case will be described, in the present invention, the exhaust chamber 12 may be provided outside the slow cooling furnace 6. The method is not shown, and the exhaust chamber 12 is provided in the cooling annealing furnace 7 adjacent to the outlet of the slow cooling furnace 6, that is, the entire end portion of the surrounding structure 10 of the slow cooling furnace 6 is removed. The exhaust chamber 12 is provided in the lower portion, and the slow cooling furnace 6 is distinguished from the cooling annealing furnace 7 having no surrounding structure. As a result, the exhaust chamber 12 is formed as a portion of the cooling furnace 6 to form a portion of the surrounding structure 10 of the slow cooling furnace 6. In the present invention, when the exhaust chamber 12 is provided at the end of the slow cooling furnace 6, the exhaust chamber 12 is placed adjacent to the outlet portion of the slow cooling furnace 6 in the cooling annealing furnace.

According to this method, the entire environment in the slow cooling furnace 6 is guided to the exhaust chamber 12 and flows over the entire area from the upstream portion to the end of the slow cooling furnace 6, and the sulfite is formed around the glass ribbon 1. The gas stream is passed, and the remaining sulfurous acid gas is discharged from the end of the slow cooling furnace 6. Therefore, if the exhaust chamber 12 is disposed in the intermediate portion or the downstream portion of the slow cooling furnace 6, substantially no part of the sulfurous acid gas is returned to the back of the exhaust chamber 12 and remains in the slow cooling. The inside of the furnace 6. Further, in this method, the exhaust chamber 12 can be provided by a cooling annealing furnace having no surrounding structure, so that the slow cooling furnace 6 can be largely modified, which is preferable.

Fig. 3 shows another preferred embodiment of the present invention. In the present example, as shown in the drawing, an air supply chamber 19 is provided on the downstream side of the exhaust chamber 12 provided at the downstream portion of the slow cooling furnace 6, and external air is supplied from the air supply chamber 19 to the exhaust chamber. The glass ribbon 1 behind the chamber 12 forms an environment with a positive pressure relative to the outside behind the exhaust chamber 12. Here, the back of the exhaust chamber 12 refers to the rear side of the exhaust chamber 12 in the transport direction of the glass ribbon 1, and specifically, is disposed downstream of the exhaust chamber 12 in the slow cooling furnace 6. The part near the side (the opposite side of the floating bath 2). When the exhaust chamber 12 is provided in the slow cooling furnace 6, the back of the exhaust chamber 12 is generally not easily subjected to a negative pressure state due to the suction of the exhaust chamber 12. Therefore, when the exhaust chamber 12 is provided at the end of the slow cooling furnace 6 as described above, dust or the like may flow into the slow cooling furnace 6 from the outlet portion of the slow cooling furnace 6 together with the outside air, and adhere thereto. The surface of the glass ribbon 1. In this example, the inflow of such dust or the like is prevented by the air supply chamber 19.

That is, as shown in FIG. 3, an air supply chamber 19 is arranged side by side on the downstream side of the exhaust chamber 12, and external air is supplied from the air supply chamber 19 to the glass ribbon 1 behind the exhaust chamber 12. The back of the exhaust chamber 12 is made positive with respect to the outside. The air supply chamber 19 has the same cylindrical structure 28 as the above-described exhaust chamber 12, and the cylindrical structure 28 is also substantially the same in shape and arrangement as the exhaust chamber 12 (however, preferably, the cylinder The lower end of the downstream side of the structure 28 is farther from the glass ribbon than the lower end of the upstream side, particularly preferably 20 to 70 mm. The upper portion of the tubular structure 28 is provided with a gas supply pipe 20 for gas supply. The air supply tube 20 is in communication with the air supply chamber 19. An air supply fan 21 and a damper 22 are provided in the air supply pipe 20. The air supply system of the air supply chamber 19 is realized by driving the air supply fan 21 by the drive motor 23, and the air supply amount of the air supply chamber 19 can be controlled by controlling the rotation speed of the air supply fan 21 and/or changing the opening degree of the damper 22. Adjustment.

Further, on the downstream side of the exhaust chamber 12 (between the exhaust chamber 12 and the supply air chamber 19 when the air supply chamber 19 is provided), it is preferably carried in the slow cooling furnace 6. A separator 26 is disposed above and/or below the glass ribbon 1 in the process (the separator above the glass ribbon is not shown in Fig. 3). The reason for this is that the exhaust efficiency or the gas supply efficiency can be improved.

When the spacer 26 is disposed above the glass ribbon 1, the spacing between the spacer 26 and the glass ribbon 1 is preferably 10 to 100 mm, more preferably 10 to 50 mm; when the spacer 26 is placed on the glass ribbon In the case of 1 below, the distance between the separator 26 and the glass ribbon 1 or the distance between the front end of the separator and the outer circumference of the conveying roller is preferably 10 to 100 mm, more preferably 10 to 50 mm. The width of the separator 2 is preferably greater than the width of the venting chamber 12.

As described in this example, the air supply chamber 19 is arranged side by side in the exhaust chamber 12, whereby the back (downstream side) of the exhaust chamber 12 is maintained relative to the outside by the air supply to the air supply chamber 19. It is a positive pressure of about 1 to 10 Pa, and therefore, it is possible to prevent a part of the sulfurous acid gas guided to the exhaust chamber 12 from flowing behind the exhaust chamber 12. In particular, when the exhaust chamber 12 and the supply chamber 19 are provided at the end of the slow cooling furnace 6 as described in this example, it is possible to prevent a part of the sulfurous acid gas from flowing to the back of the exhaust chamber 12 and further slowing down The end portion of the cooling furnace 6 flows out to the side of the cooling annealing furnace. Further, since the end portion of the slow cooling furnace 6 or the rear portion of the air supply chamber 19 is positively pressed with respect to the outside, it is possible to prevent dust or the like from flowing into the slow cooling furnace 6 from the outside.

As described above, the preferred embodiment of the present invention has been described. Preferably, the structure of the exhaust chamber 12 and the air supply chamber 19 exposed to the upper environment of at least the glass ribbon 1 in the slow cooling furnace 6 is preferably Formed from an acid-resistant, non-combustible material. The reason is that if it is formed of a material that is weak in acid resistance, it will be corroded by sulfurous acid gas, and the corrosive substance will fall onto the glass ribbon, or adhere or fix on the surface of the roller, thereby causing foreign matter adhesion on the surface of the glass ribbon. Or defects such as defects, resulting in a decrease in the quality of the obtained float glass and a decrease in yield. Examples of the acid-resistant incombustible material include stainless steel, caster casting, ceramic lining, and Teflon (registered trademark) processing.

Further, if the inside of the cooling furnace 6, the inside of the exhaust chamber 12, the inside of the exhaust pipe 15, and the inside of the air supply pipe 20 are equal to or lower than the acid dew point temperature (100 to 200 ° C) of the sulfurous acid gas, the cooling furnace 6 is cooled. The sulfurous acid gas sprayed on the lower surface of the glass ribbon 1 will condense when it comes into contact with the same phase, and the condensation will fall onto the glass ribbon to contaminate the glass ribbon. Therefore, it is preferable to cool the inside of the cooling furnace 6 and the exhaust chamber. The temperature in the chamber 12, the supply air chamber 19, the exhaust pipe 15, and the air supply pipe 20 maintain a higher acid dew point of the sulfuric acid gas.

Further, it is preferable that a gas scrubber that communicates with the exhaust pipe 15 for exhausting the sulfurous acid gas is provided at a front end of the exhaust pipe 15 that communicates with the exhaust chamber 12.

The present invention has been described in detail with reference to the specific embodiments of the present invention. It is understood that various changes and modifications may be made without departing from the spirit and scope of the invention.

The present application is based on Japanese Patent Application No. 2009-282459, filed on Dec.

[Industrial availability]

The present invention is suitable for a floating method in which sulfurous acid gas is sprayed to a floating glass in a high temperature region of a slow cooling furnace of a floating glass manufacturing apparatus, and the sulfate is used to prevent bismuth. Protect the film.

1, 41. . . Glass belt

2, 42. . . Floating bath

3,43. . . Molten tin

4, 44. . . Ribbon glass

5, 45. . . Pinch

6, 46. . . Slow cooling furnace

7, 47. . . Cooling annealing furnace

8, 48. . . Pinch roll

9, 10. . . Surrounding structure

11, 51. . . Transfer roller

12. . . Exhaust chamber

13,53. . . Cutting device

14, 54. . . nozzle

15. . . exhaust pipe

16. . . throttle

17. . . Exhaust fan

18. . . Drive motor

19. . . Air supply chamber

20. . . Airway

twenty one. . . Air supply fan

twenty two. . . throttle

twenty three. . . Drive motor

26. . . Isolation board

27. . . Cylindrical structure

28. . . Cylindrical structure

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal cross-sectional explanatory view showing a floating glass manufacturing apparatus according to a preferred embodiment of the present invention.

Figure 2 is a plan view of the A-A portion of Figure 1 (only half of which is shown).

Fig. 3 is a cross-sectional explanatory view showing a distal end portion of a slow cooling furnace of a floating glass manufacturing apparatus according to another preferred embodiment of the present invention.

Figure 4 is a cross-sectional explanatory view of a prior floating glass manufacturing apparatus.

1. . . Glass belt

2. . . Floating bath

3. . . Molten tin

4. . . Ribbon glass

5. . . Pinch

6. . . Slow cooling furnace

7. . . Cooling annealing furnace

8. . . Pinch roll

9. . . Surrounding structure

10. . . Surrounding structure

11. . . Transfer roller

12. . . Exhaust chamber

13. . . Cutting device

14. . . nozzle

15. . . exhaust pipe

16. . . throttle

17. . . Exhaust fan

18. . . Drive motor

27. . . Cylindrical structure

Claims (16)

A method for producing a floating glass, comprising: transporting a glass ribbon that has been formed in a float bath and lifted from the float bath by a pinch portion to a slow cooling of the glass ribbon to a temperature below a strain point temperature of the glass In the method for producing a floating glass, the nozzle provided in the upstream portion of the slow cooling furnace supplies sulfurous acid gas to the lower surface of the glass ribbon during the conveyance in the slow cooling furnace. Further, the exhaust chamber is provided only in a region downstream of the position where the nozzle is provided, that is, in the middle portion or the downstream portion of the slow cooling furnace, and the environment in the slow cooling furnace is sucked, thereby making the sulfurous acid on the one hand The gas stream is formed around the glass ribbon in the direction in which the glass ribbon is conveyed, and the gas stream is guided to the exhaust chamber to discharge the remaining sulfurous acid gas to the outside. The manufacturing method of the floating glass of claim 1, wherein a supply air chamber is provided on a downstream side of the exhaust chamber, and an external air is supplied from the air supply chamber to the glass ribbon, thereby being in the exhaust chamber Behind the chamber is an environment that is positively pressed against the outside. The method for manufacturing a floating glass according to claim 1 or 2, wherein the rotation speed of the exhaust fan provided in the exhaust pipe communicating with the exhaust chamber and/or the opening of the damper provided in the exhaust pipe Degree is controlled to adjust the amount of exhaust. The method for manufacturing a floating glass according to claim 2, wherein the rotation speed of the air supply fan provided in the air supply pipe connected to the air supply chamber and/or the opening degree of the damper provided in the air supply pipe is controlled, And adjust the amount of gas. The method for producing a float glass according to claim 1 or 2, wherein the inside of the slow cooling furnace and the exhaust chamber are maintained at a temperature equal to or higher than an acid dew point of the sulfite gas. The method for producing a float glass according to claim 3, wherein the inside of the slow cooling furnace and the exhaust chamber are maintained at a temperature equal to or higher than an acid dew point of the sulfite gas. The method for producing a float glass according to claim 4, wherein the inside of the slow cooling furnace and the exhaust chamber are maintained at a temperature equal to or higher than an acid dew point of the sulfite gas. A floating glass manufacturing apparatus comprising a slow cooling furnace that has been formed in a floating bath and is slowly cooled by a gripping portion from the floating bath to a strain point temperature of the glass, the floating glass In the manufacturing apparatus, a nozzle is provided in an upstream portion of the slow cooling furnace, and the nozzle sprays sulfite gas on a lower surface of the glass ribbon during transport by the transfer roller in the slow cooling furnace, and is only provided A region downstream of the position of the nozzle, that is, a middle portion or a downstream portion of the slow cooling furnace, is provided above the glass ribbon with an exhaust chamber for sucking the environment in the slow cooling furnace. The floating glass manufacturing apparatus according to claim 8, wherein the downstream side of the exhaust chamber is provided with an environment for supplying external gas to the glass ribbon and forming a positive pressure with respect to the outside behind the exhaust chamber The air supply chamber. The floating glass manufacturing apparatus of claim 8 or 9, wherein the downstream side of the exhaust chamber is in the process of transporting in the slow cooling furnace A separator is provided above and/or below the glass ribbon. The floating glass manufacturing apparatus according to claim 8 or 9, wherein the structure in the environment exposed above the glass ribbon in the process of transporting in the slow cooling furnace is formed of an acid-resistant incombustible material. The floating glass manufacturing apparatus according to claim 10, wherein the structure in the environment exposed above the glass ribbon in the process of transporting in the slow cooling furnace is formed of an acid-resistant incombustible material. The floating glass manufacturing apparatus according to claim 8 or 9, wherein a front end of the exhaust pipe connected to the exhaust chamber is provided to communicate with the exhaust pipe for exhausting the sulfurous acid gas. Scrubber. The floating glass manufacturing apparatus of claim 10, wherein at the front end of the exhaust pipe connected to the exhaust chamber, there is provided a scrubbing gas connected to the exhaust pipe for exhausting the sulfurous acid gas Device. The floating glass manufacturing apparatus of claim 11, wherein at the front end of the exhaust pipe connected to the exhaust chamber, there is provided a scrubbing gas connected to the exhaust pipe for exhausting the sulfurous acid gas Device. The floating glass manufacturing apparatus of claim 12, wherein at the front end of the exhaust pipe connected to the exhaust chamber, there is provided a scrubbing gas connected to the exhaust pipe for exhausting the sulfurous acid gas Device.