KR20110068896A - Method and apparatus for producing float glass - Google Patents

Abstract

PURPOSE: A manufacturing method and manufacturing device of the float glass is provided to form a protective film against scratches on the lower part of the glass ribbon by spraying sulfur dioxide gas to a float glass as to a high temperature area of an annealing furnace. CONSTITUTION: The manufacturing device of the float glass includes an annealing furnace(6) annealing a glass ribbon(1) pulled up from a float bath(2) below a distortion point temperature of the glass; a nozzle(14), which is installed in the upstream of the annealing furnace and provides sulfur dioxide gas to the lower part of the glass ribbon going back to the annealing furnace; and an exhaust chamber(12), which is installed in a lower area than the nozzle installation area, and inhales air inside of the annealing furnace. The manufacturing method of the float glass includes following steps.(a) The air current of the sulfur dioxide gas around the glass ribbon is formed at the opposite direction of the glass ribbon, and the air current is induced inside of the exhaust chamber.(b) And surplus sulfur dioxide gas is discharged to outside.

Description

Manufacturing method and apparatus for manufacturing float glass {METHOD AND APPARATUS FOR PRODUCING FLOAT GLASS}

TECHNICAL FIELD This invention relates to the manufacturing method and manufacturing apparatus of a float glass. Specifically, It is related with the manufacturing method and manufacturing apparatus of the float glass which forms the protective film for flaw prevention in a slow cooling furnace.

As shown in FIG. 4, the molten glass is supplied onto the molten tin 43 of the float bath 42 to be molded into a ribbon glass 44 having a desired thickness and width. The molded ribbon-shaped glass 44 is pulled up by the lift out roll 48 of the lift out part 45 provided adjacent to the float bath 42 from the exit of the float bath 42, and then the slow cooling furnace Slow cooling and cooling at 46 form a glass ribbon (float glass) 41. And this glass ribbon 41 is cooled to the room temperature which can be cut | disconnected by the cooling rare 47 again, and is cut | disconnected by the cutting device 53 to predetermined size. During this time, the glass ribbon 41 is continuously produced by being pulled and conveyed by the conveying roll 51.

In the above-mentioned float glass manufacturing process, in order to prevent generation | occurrence | production of the flaw by the said conveyance roll 51, or the occurrence of a flaw at the time of conveyance or conveyance after that, the sulfite is formed on the plate surface of the molded glass ribbon 41. It is known to form a protective film of sulfate by injecting gas (SO ₂ ). For example, Patent Document 1 provides a nozzle 54 for injecting sulfurous acid gas in an upstream region of the slow cooling furnace 46 as shown in FIG. 4, and provides the slow cooling furnace 46 from the nozzle 54. It is described to form a protective film by injecting sulfurous acid gas into the glass ribbon 41 conveying the inside with the conveyance roll 51. The sulfurous acid gas injected into the glass ribbon 41 in the high temperature slow cooling furnace 46 reacts with the constituents of the glass and the like, and a protective film of sulfate such as sodium sulfate is formed on the surface of the glass ribbon 41. The protective film of this sulfate is finally removed by washing.

International Publication No. 02/051767

When forming the protective film of sulfate in the slow cooling furnace of a float glass manufacturing apparatus, injection of sulfite gas is performed upstream of a slow cooling furnace with high temperature. In Patent Literature 1, by installing a nozzle in an area partitioned by a partition wall upstream of a slow cooling furnace and injecting sulfurous acid gas, the concentration of sulfurous acid gas in the area is increased to improve reaction efficiency with glass, and a protective film is formed on the glass ribbon. It is effectively formed on the surface. However, even when sulfurous acid gas is injected in the area partitioned by the partition wall, excess sulfurous acid gas flows out into the slow cooling furnace, and the sulfite gas stays in the slow cooling furnace or leaks out again from the slow cooling furnace.

Such surplus sulfurous acid gas in the slow cooling furnace not only corrodes the structure of the slow cooling furnace or flows into the lift out portion adjacent to the slow cooling furnace from the gap between the conveying rolls, but also damages the structure of the lift out portion in the same way, and causes great damage. The rust and corrosives of the corroded structure drop on the surface of the glass ribbon or adhere to or adhere to the roll surface, resulting in defects such as foreign matter adherence and scratches on the glass ribbon surface. It is causing.

Therefore, in Patent Literature 1, when sulfite gas forms an injection protective film in a shielded rare (lift out portion), sulfurous acid gas flows from the shield rare into the float bath to contaminate the molten tin of the float bath. In order to prevent it from being made, it is described that a suction nozzle is provided adjacent to the nozzle, and the excess sulfurous acid gas which is not used for forming a protective film of the glass ribbon is sucked out of the injected sulfurous acid gas and discharged out of the system. However, in such a method, it is difficult to solve the said problem in a slow cooling furnace.

This invention is made | formed in view of the said subject, and can form reliably a protective film of sufficient thickness in the plate surface of a glass ribbon, and also prevents the leakage of the sulfite gas from the inside of slow cooling furnace to the outside, and corrosion of the structure of a slow cooling furnace. It aims at providing the manufacturing method and manufacturing apparatus of the float glass which can be reduced or prevented.

This invention was obtained by earnestly examining in order to achieve the said objective, and it is made into the slow cooling furnace which slowly cools the glass ribbon shape | molded by the float bath and pulled out from the said float bath at the lift out part below the strain point temperature of glass. It is a manufacturing method of the float glass containing the process to convey,

The sulfite gas is supplied to the lower surface of the glass ribbon conveying the inside of the slow cooling furnace from the nozzle provided upstream of the slow cooling furnace, and an exhaust chamber is provided in an area downstream from the position where the nozzle is provided to provide the slow cooling. By sucking the atmosphere in the furnace, while drawing the air flow of the sulfurous acid gas in the conveying direction of the glass ribbon around the glass ribbon, the air flow is attracted to the exhaust chamber, and the excess sulfurous acid gas is discharged to the outside, Provided are methods for producing float glass.

It is preferable to form an air supply chamber downstream from the exhaust chamber and to supply external air from the air supply chamber toward the glass ribbon to form a positive pressure atmosphere behind the exhaust chamber.

It is preferable to control the displacement by controlling the rotational speed of the exhaust fan provided in the exhaust duct communicating with the exhaust chamber and / or the opening degree of the damper provided in the exhaust duct.

It is preferable to control the air supply amount by controlling the rotation speed of the air supply fan provided in the air supply duct communicating with the air supply chamber and / or the opening degree of the damper provided in the air supply duct.

It is preferable to maintain the inside of the slow cooling furnace and the inside of the exhaust chamber at a temperature not lower than the acid dew point of the sulfurous acid gas.

Moreover, this invention is a manufacturing apparatus of the float glass which has a slow cooling furnace which shape | molds in the float bath and pulls up the glass ribbon pulled out from the said float bath at the lift out part below the strain point temperature of glass,

The slow cooling furnace is provided in the upstream part of the said slow cooling furnace in the area | region downstream from the position where the said nozzle is installed in the lower surface of the said glass ribbon conveying the inside of the slow cooling furnace with a conveyance roll, and the said nozzle is provided. It provides the float glass manufacturing apparatus in which the exhaust chamber which attracts the atmosphere inside is provided above the said glass ribbon.

It is preferable that an air supply chamber is provided downstream of the exhaust chamber to supply the outside air toward the glass ribbon to form a positive pressure atmosphere to the outside behind the exhaust chamber.

It is preferable that a partition plate is provided above and / or below the said glass ribbon conveying the inside of the said slow cooling furnace downstream from the said exhaust chamber.

It is preferable that the structure exposed to the atmosphere above the said glass ribbon conveying the inside of the said slow cooling furnace is formed with the acid-resistant nonflammable material.

It is preferable that a scrubber for exhaust gas treatment of the sulfurous acid gas is provided in communication with the exhaust duct at the end of the exhaust duct communicating with the exhaust chamber.

According to this invention, since the airflow of the atmosphere containing sulfurous acid gas around a glass ribbon is formed in the conveyance direction of a glass ribbon, a protective film can also be formed also by the sulfurous acid gas supported by this airflow. As a result, since a protective film is efficiently formed especially in the lower surface of a glass ribbon, generation | occurrence | production of the scratch by a conveyance roll can be prevented. In addition, it is possible to reduce or prevent leakage of sulfurous acid gas from the slow cooling furnace to the outside and corrosion of the structure of the slow cooling furnace.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional explanatory drawing of the float glass manufacturing apparatus which concerns on preferable embodiment of this invention.
FIG. 2 is a plan view (half shown only) in the AA portion of FIG. 1. FIG.
Fig. 3 is a cross-sectional explanatory diagram of a terminal portion of a slow cooling furnace of a float glass manufacturing apparatus according to another preferred embodiment of the present invention.
4 is a cross-sectional explanatory diagram of a conventional float glass manufacturing apparatus.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings. In addition, in this specification, the lower surface of a glass ribbon is the surface of the side which a glass ribbon contact | connects a conveyance roll, and the lower side is the direction which the said lower surface is facing, and the upper side of a glass ribbon is the opposite side to the said lower surface. Points in the direction that the face (top) is facing.

1: is a longitudinal cross-sectional explanatory drawing of the float glass manufacturing apparatus which concerns on preferable embodiment of this invention, and FIG. 2 is a top view in the A-A part. Although only half of the slow cooling furnace is shown in FIG. 2, the half not shown is also symmetrical and the same. As shown, the glass ribbon 1 shape | molded with the ribbon glass 4 on the molten tin 3 of the float bath 2 is provided in the lift-out part 5 of the exit of the float bath 2. It is pulled up from the molten tin 3 by the lift out roll 8, and is conveyed to the slow cooling furnace 6 provided in the lift out part 5 continuously. In the lift out part 5, the lift out roll 8 is arrange | positioned at the level higher than the molten tin surface of the float bath 2, and the glass ribbon 1 shape | molded with the ribbon glass 4 in the float bath 2 ) Is pulled up by the lift-out roll 8, and is cooled and conveyed to the slow cooling furnace 6 until it becomes stable in the lift-out part 5 having the enclosure structure 9.

The slow cooling furnace 6 is a temperature-adjustable facility which has the surrounding structure 10 similarly to the slow cooling furnace generally used in manufacture of many glass products, and several conveyance rolls 11 are installed in parallel inside. . These conveying rolls 11 are driven at a fixed speed by a drive motor (not shown), and pull or convey the ribbon-shaped glass ribbon 1 at a fixed fixed speed. In this case, some conveyance rolls may rotate freely without drive connection to a drive motor. The slow cooling furnace 6 has a length of several tens of m, and the temperature in the slow cooling furnace 6 having the enclosing structure 10 varies from the high temperature of the upstream portion (for example, about 600 to 750 ° C) to the downstream end temperature. It is temperature-controlled so that the temperature distribution which feels bodily to (for example, about 200-400 degreeC) is obtained. Thereby, while the glass ribbon 1 conveys the inside of the slow cooling furnace 6 with the conveyance roll 11, it cools slowly to the temperature below the strain point temperature of glass so that undesirable thermal stress may not remain in glass. And normally, until it reaches the exit of the slow cooling furnace 6, the glass ribbon 1 is cooled until it becomes temperature lower than the strain point temperature of glass. Since the glass ribbon 1 cooled by the slow cooling process of the slow cooling furnace 6 still has the high temperature of about 200-400 degreeC at the exit of the slow cooling furnace 6, as mentioned above, it is further made to cool by the cooling rare 7. After cooling to the temperature which can be cut | disconnected, it cut | disconnects to predetermined size by the cutting device 13. The cooling rare 7 may not be a facility which can adjust the temperature which has the surrounding structure 10 like the slow cooling furnace 6, as long as the slow cooled glass ribbon can be cooled to near room temperature.

In the present invention, as shown in Fig. 1, a nozzle 14 for injecting sulfurous acid gas is provided on the lower surface of the glass ribbon 1 upstream of the slow cooling furnace 6, and the nozzle 14 is further provided. By installing the exhaust chamber 12 in a region downstream from the position (sulfite gas injection position) and sucking the atmosphere in the slow cooling furnace 6, the sulfite gas in the upstream part contains sulfurous acid gas around the glass ribbon 1 It forms in the conveyance direction of the glass ribbon 1 as airflow of an atmosphere, attracts to the exhaust chamber 12, and discharges it from the exhaust chamber 12 to the outside. Thereby, in the slow cooling process of the slow cooling furnace 6, the sulfite gas is sprayed into the nozzle 14 in the lower surface of the glass ribbon 1 which is in the high temperature state of an upstream part, and the formation of the flaw prevention protective layer (protective film) which consists of sulfates is formed. This prevents the occurrence of scratches by the conveyance roll and the occurrence of scratches during subsequent conveyance or transportation.

In this invention, by providing the said nozzle 14 in the upstream part of the slow cooling furnace 6, sulfurous acid gas is inject | poured on the lower surface of the high temperature glass ribbon 1, and a protective film can be formed suitably. At higher temperatures, a protective film made of sulfate derived from sulfurous acid gas is more likely to be formed on the lower surface of the glass ribbon 1. In this invention, the upstream part of the slow cooling furnace 6 is the area | region managed by high temperature in this way. Although the temperature of the glass ribbon 1 suitable for protective film formation may differ slightly according to the kind of glass etc., 500-750 degreeC is preferable and 600-750 degreeC is more preferable.

As a gas used for formation of a protective film, sulfurous acid gas is preferable. The sulfurous acid gas reacts with the chemical component in the glass to form a film of sulfate such as sodium sulfate on the plate surface of the glass ribbon 1, and the film can be easily removed by water washing. Although sulfurous acid gas is normally used independently, you may contain other gas as needed. When sulfurous acid gas is injected into the glass ribbon 1 in the upstream portion of the slow cooling furnace 6, sulfurous acid gas is, for example, so as to rapidly cool the glass ribbon having a temperature higher than the strain point so that the slow cooling process is not damaged. It is preferable to preheat about 400-600 degreeC.

In the present invention, the exhaust chamber 12 is provided in a region downstream from the position where the nozzle 14 is provided. 1 is an example in which the exhaust chamber 12 is provided downstream of the slow cooling furnace 6. Most of the sulfurous acid gas injected from the nozzle 14 to the glass ribbon 1 in the upstream portion of the slow cooling furnace 6 reacts with the glass component of the glass ribbon 1 to form a film of sulfate. Although formed on the lower surface, the remaining sulfurous acid gas is contained in the atmosphere in the furnace upstream of the slow cooling furnace 6. The exhaust chamber 12 sucks the atmosphere containing sulfurous acid gas in the furnace of this upstream part in a downstream direction, thereby conveying the airflow of the atmosphere containing sulfurous acid gas around the glass ribbon 1 in the conveyance direction of the glass ribbon 1. To prevent the stagnant state of sulfurous acid gas from occurring in the slow cooling furnace 6, and to form a protective film by an airflow in an atmosphere containing sulfurous acid gas formed around the glass ribbon 1, It also has the function of discharging excess sulfurous acid gas to the outside. If the exhaust chamber 12 is provided at the terminal end (downstream end) of the slow cooling furnace 6, the airflow of the atmosphere containing sulfurous acid gas is attracted to the terminal end of the slow cooling furnace 6, and is discharged by the exhaust chamber 12. Since it is exhausted, a part of airflow can be prevented from flowing to the rear (downstream side) of the exhaust chamber 12. However, the installation position of the exhaust chamber 12 may be a region downstream from the gas injection position, and may be a middlestream portion or a downstream portion of the slow cooling furnace 6. However, it is preferable to provide in the glass temperature range (less than 500 degreeC) lower than the glass ribbon temperature suitable for protective film formation.

The exhaust chamber 12 has a tubular structure 27 for efficiently sucking an atmosphere containing sulfurous acid gas in the slow cooling furnace 6, and has an intake atmosphere in the upper portion of the tubular structure 27. An exhaust duct 15 for discharging to the outside is provided. The exhaust duct 15 is in communication with the exhaust chamber 12. Although the shape of the cylindrical structure 27 is not specified, in order to suck in the atmosphere in the slow cooling furnace 6 uniformly in the width direction of the slow cooling furnace 6 as much as possible, as shown in FIG. Both sides of the rectangular shape, preferably have a glass ribbon width or more, more preferably has a size projecting outward from the end of the conveying roll (11). Although the width a of the cylindrical structure 27 is mainly determined by the furnace internal capacity of the slow cooling furnace 6, 0.5-4 m is preferable as the magnitude | size. If a has such a size, the atmosphere in the slow cooling furnace 6 can be sucked gently, without interrupting slow cooling operation. If a is too small, a pressure loss occurs, which is not preferable. And the atmosphere in the slow cooling furnace 6 is aspirated at the position relatively close to the glass ribbon 1, and the airflow of the atmosphere containing sulfurous acid gas is formed in the vicinity of the glass ribbon 1 as much as possible, and therefore the cylindrical structure 27 It is preferable that the lower end portion of the) is set to be a predetermined distance (preferably from 10 to 100 mm, more preferably from 10 to 50 mm) from the glass ribbon 1. In that case, it is preferable that the lower end part of the upstream side of the cylindrical structure 27 is spaced apart from a glass ribbon rather than the lower end part of a downstream side, and it is especially preferable that it is 20-70 mm apart.

The exhaust of the exhaust chamber 12 is performed by driving the exhaust fan 17 provided in the exhaust duct 15 by the drive motor 18. In the exhaust duct 15, a damper 16 may be provided to adjust the displacement of the exhaust chamber 12. When the damper 16 is provided in the exhaust duct 15 in this manner, the exhaust amount of the exhaust chamber 12 is adjusted by controlling the rotation speed of the exhaust fan 17 and / or the opening degree of the damper 16. Can be. The displacement of the exhaust chamber 12 is adjusted while taking into account the injection amount of sulfurous acid gas by the nozzle 14.

In the slow cooling furnace 6 shown in FIG. 1, as described above, the exhaust chamber 12 is provided at the end of the slow cooling furnace 6, and the exhaust chamber 12 is disposed inside the slow cooling furnace 6. Although the case where it installed is demonstrated, in this invention, the exhaust chamber 12 can be installed outside the furnace of the slow cooling furnace 6. In this method, although not shown, the exhaust chamber 12 is provided in the cooling rare 7 adjacent to the outlet, which is the end of the slow cooling furnace 6, specifically, with the cooling rare 7 having no enclosing structure. The exhaust chamber 12 is provided by removing all or the lower end of the end portion of the surrounding structure 10 of the slow cooling furnace 6 partitioned between. As a result, the exhaust chamber 12 forms the terminal part of the slow cooling furnace 6, and forms the part of the surrounding structure 10 of the slow cooling furnace 6. As shown in FIG. In the present invention, the exhaust chamber 12 is provided at the end of the slow cooling furnace 6 in the case where the exhaust chamber 12 is installed in the cooling rare adjacent to the outlet of the slow cooling furnace 6 in this way. It includes.

According to this method, the whole atmosphere in the slow cooling furnace 6 is attracted to the exhaust chamber 12, flows the whole region from the upstream part to the termination part of the slow cooling furnace 6, and the sulfurous acid gas around the glass ribbon 1 Airflow containing is formed, and excess sulfurous acid gas is exhausted from the end of the slow cooling furnace (6). Therefore, as in the case where the exhaust chamber 12 is installed in the midstream portion or the downstream portion of the slow cooling furnace 6, there is practically no fear that a part of the sulfurous acid gas remains behind the exhaust chamber 12 and remains in the cooling furnace 6. . This method is also excellent in that the exhaust chamber 12 can be installed by using a cooling rarer having no enclosing structure, so that the slow cooling furnace 6 does not have to be largely remodeled.

3 shows another preferred embodiment of the present invention. In this example, an air supply chamber 19 is provided downstream from the exhaust chamber 12 provided downstream of the slow cooling furnace 6, and the outside air is exhausted from the air supply chamber 19. It is supplied toward the glass ribbon 1 behind, and atmosphere of positive pressure is formed with respect to the exterior behind the exhaust chamber 12. Here, the back of the exhaust chamber 12 means the back side of the exhaust chamber 12 in the conveyance direction of the glass ribbon 1, and specifically, the exhaust chamber (13) installed in the slow cooling furnace 6 ( The part near the downstream side (side opposite to the float bath 2) of 12) is pointed out. When the exhaust chamber 12 is provided in the slow cooling furnace 6, the negative pressure state tends to generate | occur | produce generally behind the exhaust chamber 12 by the suction action of the exhaust chamber 12. As shown in FIG. Therefore, when the exhaust chamber 12 is provided at the end of the slow cooling furnace 6 as described above, dust and the like flow into the slow cooling furnace 6 from the outlet of the slow cooling furnace 6 together with the outside air. There exists a possibility of adhering to the surface of the glass ribbon 1. This example prevents the inflow of dust and the like by the air supply chamber 19.

That is, as shown in FIG. 3, the air supply chamber 19 is provided in the downstream side rather than the exhaust chamber 12, and the glass ribbon 1 behind the exhaust chamber 12 is removed from the air supply chamber 19. It supplies toward and makes the back of the exhaust chamber 12 into a positive pressure with respect to the exterior. The air supply chamber 19 has the same tubular structure 28 as the exhaust chamber 12 described above, and the shape and installation method of the tubular structure 28 are basically the same as those of the exhaust chamber 12. [It is preferable that the lower end part of the downstream side of the end cylindrical structure 28 is spaced apart from a glass ribbon rather than the lower end part of an upstream side, and it is preferable that it is especially 20-70 mm apart.] The upper part of the cylindrical structure 28 In the air supply air supply duct 20 is provided. The air supply duct 20 communicates with the air supply chamber 19. In the air supply duct 20, an air supply fan 21 and a damper 22 are provided. Air supply of the air supply chamber 19 is performed by driving the air supply fan 21 with the drive motor 23, and the air supply amount of the air supply chamber 19 is controlled by controlling the rotation speed of the air supply fan 21, and / or The opening degree of the damper 22 can be adjusted by changing.

Moreover, the glass ribbon 1 conveying the inside of the slow cooling furnace 6 in the downstream side (if there exists the air supply chamber 19) between the exhaust chamber 12 and the air supply chamber 19. It is preferable to provide the partition plate 26 above and / or below (the partition plate above a glass ribbon is not shown in FIG. 3). This is because the exhaust efficiency or the air supply efficiency increases.

When installing the partition plate 26 above the glass ribbon 1, the space | interval of the partition plate 26 and the glass ribbon 1 is 10-100 mm, Furthermore, 10-50 mm is preferable, and the partition plate ( In the case where 26 is provided below the glass ribbon 1, the interval between the partition plate 26 and the glass ribbon 1 or the interval between the partition plate tip and the transport roll outer circumference is 10 to 100 mm, further 10 to 50 mm. Is preferred. It is preferable that the width of the partition plate 26 is wider than the width of the exhaust chamber 12.

By providing the air supply chamber 19 in the exhaust chamber 12 as in this example, the backside (downstream side) of the exhaust chamber 12 is supplied at a constant pressure of about 1 to 10 Pa with respect to the outside by the air supply of the air supply chamber 19. Since it is retained, a part of the sulfurous acid gas attracted to the exhaust chamber 12 can be prevented from flowing behind the exhaust chamber 12. In particular, when the exhaust chamber 12 and the air supply chamber 19 are provided at the end of the slow cooling furnace 6 as in this example, part of the sulfurous acid gas flows behind the exhaust chamber 12 and then again. It can prevent that it flows out from the terminal part of the slow cooling furnace 6 to the cooling rare side. Moreover, since the terminal part of the slow cooling furnace 6 or the back part of the air supply chamber 19 becomes a positive pressure with respect to the exterior, it can prevent dust etc. from entering into the slow cooling furnace 6 from the exterior.

As mentioned above, although preferred embodiment of this invention was described, structures, such as the exhaust chamber 12 and the air supply chamber 19, exposed to the atmosphere above at least the glass ribbon 1 of the slow cooling furnace 6, are acid resistant. It is preferable that it is formed with the nonflammable material of. If it is formed of a material having a weak acid resistance, it is corroded by sulfurous acid gas, and the corrosive drops on the glass ribbon or adheres to or adheres to the roll surface, resulting in defects such as foreign matter adhesion and scratches on the glass ribbon surface. The reason for this is that the quality of the glass and the yield are reduced. As this acid-resistant nonflammable material, stainless steel or caster casting, ceramic lining, Teflon (registered trademark) processing, etc. are mentioned.

In addition, when the inside of the slow cooling furnace 6, the exhaust chamber 12, the exhaust duct 15, the air supply duct 20, etc. are below the acid dew point temperature (100-200 degreeC) of sulfurous acid gas, slow cooling The sulfurous acid gas injected into the lower surface of the glass ribbon 1 in the furnace 6 condenses when it comes into contact with it, and condensation falls on the glass ribbon and contaminates the glass ribbon. The chamber 12, the air supply chamber 19, the exhaust duct 15, and the air supply duct 20 are preferably maintained at a temperature higher than the acid dew point of sulfurous acid gas.

Moreover, it is preferable that the end of the exhaust duct 15 which communicates with the exhaust chamber 12 communicates with the said exhaust duct 15, and the scrubber for exhaust gas treatment of sulfurous acid gas is provided.

Although this invention was detailed also demonstrated with reference to the specific embodiment, it is clear for those skilled in the art that various changes and correction can be added without deviating from the mind and range of this invention.

This application is based on the JP Patent application 2009-282459 of an application on December 14, 2009, The content is taken in here as a reference.

[Industrial Availability]

This invention is suitable for the float method which injects sulfurous acid gas into the float glass in the high temperature area | region of the slow cooling furnace of a float glass manufacturing apparatus, and forms the protective film for a damage prevention with the sulfate.

1: glass ribbon
2: float bath
3: molten tin
4: ribbon shape glass
5: lift out
6: slow cooling furnace
7: cooling rare
8: lift out roll
9: surrounding structure
10: surrounding structure
11: bounce roll
12: exhaust chamber
13: cutting device
14: nozzle
15: exhaust duct
16: damper
17: exhaust fan
18: drive motor
19: air supply chamber
20: air supply duct
21: air supply fan
22: damper
23: drive motor
26: partition plate
27: tubular structure
28: tubular structure

Claims (10)

It is a manufacturing method of the float glass including the process of conveying the glass ribbon shape | molded by the float bath and pulled up from the said float bath at the lift out part to the slow cooling furnace which slow-cools below the strain point temperature of glass,
The sulfite gas is supplied to the lower surface of the glass ribbon conveying the inside of the slow cooling furnace from the nozzle provided upstream of the slow cooling furnace, and an exhaust chamber is provided in an area downstream from the position where the nozzle is provided to provide the slow cooling. A float for attracting the air stream to the exhaust chamber and discharging excess sulfurous acid gas to the outside while forming an air flow of the sulfurous acid gas in the conveying direction of the glass ribbon around the glass ribbon by sucking the atmosphere in the furnace. Method of making glass. The float glass according to claim 1, wherein an air supply chamber is provided downstream from the exhaust chamber, and air is supplied from the air supply chamber toward the glass ribbon, thereby forming a positive pressure atmosphere behind the exhaust chamber. Method of preparation. The manufacture of the float glass of Claim 1 or 2 which adjusts an exhaust amount by controlling the rotation speed of the exhaust fan installed in the exhaust duct which communicates with the said exhaust chamber, and / or the opening degree of the damper provided in the said exhaust duct. Way. The manufacturing method of the float glass of Claim 2 which adjusts an air supply amount by controlling the rotation speed of the air supply fan provided in the air supply duct which communicates with the said air supply chamber, and / or the opening degree of the damper provided in the said air supply duct. The manufacturing method of the float glass of any one of Claims 1-4 which hold | maintains the inside of the said slow cooling furnace and the said exhaust chamber at the temperature more than the acid dew point of the said sulfurous acid gas. It is a manufacturing apparatus of the float glass which has a slow cooling furnace which shape | molds in a float bath and pulls out the glass ribbon pulled out from the said float bath at the lift out part below the strain point temperature of glass,
The slow cooling furnace is provided in the upstream part of the said slow cooling furnace in the area | region downstream from the position where the said nozzle is installed in the lower surface of the said glass ribbon conveying the inside of the slow cooling furnace with a conveyance roll, and the said nozzle is provided. The float glass manufacturing apparatus in which the exhaust chamber which attracts the atmosphere inside is provided above the said glass ribbon. The float glass manufacturing apparatus of Claim 6 provided with the air supply chamber downstream of the said exhaust chamber, and supplying external air toward the said glass ribbon, and forming the atmosphere of a positive pressure with respect to the exterior behind the said exhaust chamber. The float glass manufacturing apparatus of Claim 6 or 7 with which a partition plate is provided above and / or below the said glass ribbon conveying the inside of the said slow cooling furnace downstream from the said exhaust chamber. The float glass manufacturing apparatus in any one of Claims 6-8 in which the structure exposed to the atmosphere above the said glass ribbon conveying the inside of the said slow cooling furnace is formed with acid-resistant nonflammable material. The float glass manufacturing apparatus as described in any one of Claims 6-9 in which the scrubber for exhaust gas processing of the sulfurous acid gas is provided in communication with the said exhaust duct at the end of the exhaust duct which communicates with the said exhaust chamber.

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