A device for reducing molten tin contamination at the tail end of a solder bath

Abstract

This invention discloses a device for reducing molten tin contamination at the tail end of a tin bath, comprising a tin bath with a molten tin pan inside. A transition chamber is located at one end of the molten tin pan, and a slag box is located at the lower end of the transition chamber. A cooling mechanism is installed inside the slag box. A buffer chamber is located at the end of the transition chamber away from the molten tin pan, and an adjustment mechanism is located at the upper end of the buffer chamber. An annealing chamber is fixedly connected to the end of the buffer chamber away from the transition chamber. This invention can reduce the degree of contamination of molten tin in the tin bath, improve glass quality, and reduce molten tin consumption. A cooling mechanism and a pressure detection device are installed at the bottom of the slag box. The opening at the connection between the transition chamber and the annealing chamber is adjustable. A buffer chamber is located at the front end of the annealing chamber, and a gas flow rate detection device is installed in the buffer chamber to monitor the flow rate and prevent excessive gas from the transition chamber from entering the annealing chamber.

Description

Technical Field

[0001] This invention relates to the field of glass production technology, specifically to a device for reducing molten tin contamination at the tail end of a tin bath. Background Technology

[0002] In float glass production, the glass floats on molten tin in a tin bath to form its shape, and then enters the annealing chamber for annealing and cutting to become the glass product sold. The connection between the tin bath and the annealing chamber is a transition chamber, below which is the slag box. Because the molten tin in the tin bath needs to operate under a reducing protective atmosphere, and the transition chamber and slag box are connected to the tin bath, this area is usually sealed during production. Multiple partitions are installed inside the slag box to prevent the entry of external gases and contamination of the molten tin. However, in actual production, gaps exist at the seals, or some sealing and partitioning devices are damaged (such as burnt graphite strips used to clean the support rollers), resulting in imperfect sealing. This allows external gases to enter the tin bath through this point, oxidizing the molten tin and forming tin ash that floats on the surface of the molten tin. When there is a lot of tin ash, it accumulates at the end of the tin bath, requiring timely manual cleaning; otherwise, it will contaminate the lower surface of the glass, creating defects.

[0003] To mitigate molten tin contamination, gas seals have been added to the molten tin bath outlet. However, if external gases continuously enter the slag box, contamination of the molten tin remains significant despite the gas seals. Inert gas has also been introduced into the bottom of the slag box to prevent external gases from entering, but this method proved ineffective. The upper part of the connection between the transition chamber outlet and the annealing chamber is generally open, allowing the protective gas at the rear of the molten tin bath to exit through this outlet. Because the outlet is located at the top, a chimney effect is created, drawing gas from the transition chamber and the slag box. This suction effect easily creates negative pressure at the bottom of the slag box, further exacerbating the inflow of external gases into the slag box.

[0004] The pressure at the opening is the same as the ambient pressure. Based on Bernoulli's equation for gas flow, the following relationship can be derived.

[0005]

[0006] in

[0007] The pressure at the bottom of the slag box, in Pa;

[0008] The ambient atmospheric pressure is Pa.

[0009] The gas velocity at the bottom of the slag box is m / s;

[0010] The gas velocity at the open connection between the transition compartment and the annealing compartment, in m / s;

[0011] The distance from the top of the open section to the bottom of the slag box is expressed in meters (m).

[0012] The density of ambient air, kg / m³ 3 ;

[0013] The density of the gas at the bottom of the slag box is kg / m³. 3 ;

[0014] The density of the gas at the open junction between the transition compartment and the annealing compartment, kg / m³ 3 ;

[0015] To prevent external gas from entering the slag box, it should be made Make it as large as possible. As the formula shows, increasing... , reduce All of them can make Increase and The relationship needs to be determined based on the actual situation. (The right side of the formula is then compared with...) By merging the relevant items, we obtain The results, obtained through on-site measurements and numerical simulation calculations, show that under all working conditions... The variation range is between 0-3 m / s, depending on operational needs and general design practices. Between 1.8 and 2.2 meters, This is the acceleration due to gravity, which is 9.8 m / s². Therefore, in float glass production, It is a positive value. and Positive correlation, that is, increase , can enable The effect of introducing inert gas to prevent external gas from entering, as mentioned above, is not good because when introducing inert gas, in order to avoid the cold gas impacting the temperature of the glass plate and causing it to break, the gas is heated to 350 degrees Celsius. The above-mentioned approach actually reduces the risk. This reduces the pressure at this point, weakening the protective effect of the introduced gas.

[0016] It is related to the gas temperature at the outlet and is affected by the environment at the outlet, the temperature at the tail end of the tin bath, and the gas volume, so it is generally difficult to control. Due to the influence of the bottom structure of the slag box, this structure is difficult to change after construction. Once the production line is built, it is fixed and cannot be adjusted.

[0017] Therefore, increasing the size can be considered. and To increase This achieves the purpose of preventing external gases from entering the slag box and reducing molten tin contamination. Summary of the Invention

[0018] The purpose of this invention is to provide a device for reducing molten tin contamination at the tail end of the tin bath to solve the problems mentioned in the background art.

[0019] To achieve the above objectives, the present invention provides the following technical solution:

[0020] The device includes a tin bath, inside which is a molten tin pan. One end of the molten tin pan is a transition chamber, and the lower end of the transition chamber is a slag box. The slag box contains a cooling mechanism. The end of the transition chamber away from the molten tin pan is a buffer chamber, and the upper end of the buffer chamber is an adjustment mechanism. The end of the buffer chamber away from the transition chamber is fixedly connected to an annealing chamber. Support rollers are provided inside the transition chamber, the annealing chamber, and the buffer chamber.

[0021] Preferably, the cooling mechanism includes multiple cooling pipes, with multiple heat dissipation rings fixedly connected to each cooling pipe. Both ends of the cooling pipe extend through the transition chamber, and an input pipe and an output pipe are fixedly connected to the two extended ends of the cooling pipe, respectively.

[0022] Preferably, a valve is provided at the connection between the cooling pipe and the input pipe, and a flow meter is provided at the connection between the cooling pipe and the output pipe. The valve and the flow meter are respectively located on both sides of the transition chamber, and the input pipe and the output pipe are both arranged parallel to the outer wall of the transition chamber.

[0023] Preferably, the interior of the transition chamber is provided with multiple partitions, which are located at the bottom of the transition chamber. The partitions are all arranged on both sides of the cooling pipe, and a graphite strip is fixedly connected above the partition. The upper end of the graphite strip is in contact with the lower surface of the support roller.

[0024] Preferably, the adjustment mechanism includes a ventilation hole on the upper surface of the buffer chamber near the transition chamber, two pressure strips fixedly connected to the upper surface of the ventilation hole, and a sliding plate slidably connected below the two pressure strips. The sliding plate is adapted to the size of the ventilation hole, and a handle is fixedly connected to the upper surface of the sliding plate.

[0025] Preferably, a transition chamber curtain is provided above the support roller, a buffer chamber curtain is provided between the transition chamber and the buffer chamber, and an annealing chamber curtain is provided between the buffer chamber and the annealing chamber.

[0026] Preferably, a pressure detection device is provided at the bottom of the partition in the transition chamber, and a flow rate detection device is provided inside the buffer chamber.

[0027] Preferably, a Pitot tube is fixedly connected to the flow rate checking device.

[0028] Compared with existing technologies, the advantages of this invention are: it can reduce the degree of contamination of molten tin in the tin bath, improve glass quality, and reduce molten tin consumption. A cooling mechanism and pressure detection device are installed at the bottom of the slag box. The opening at the connection between the transition chamber and the annealing chamber can be adjusted to regulate the flow rate and thus the pressure at the bottom of the transition chamber. A buffer chamber is installed at the front end of the annealing chamber, and a gas flow rate detection device is installed in the buffer chamber to monitor the flow rate and prevent excessive gas from the transition chamber from entering the annealing chamber. The cooling pipe below the support roller can cool the slag box through the injected liquid, reducing the temperature at the bottom of the slag box, increasing the gas density, and thus increasing the pressure. This effectively prevents external gas from entering and avoids excessive oxygen reaching the tail end of the tin bath, contaminating the molten tin. It also reduces tin ash floating on the surface of the molten tin due to oxidation, reducing tin ash contamination of the glass surface, improving glass quality, and reducing molten tin consumption. The heat exchange method using pipeline cooling provides a gentle cooling effect, avoiding direct impact on the glass plate temperature and preventing plate breakage. Furthermore, the pipeline flow rate is adjustable, facilitating temperature control by operators. A flow rate detection device is installed at the front end of the annealing chamber to monitor and control the gas flow rate entering the annealing chamber, preventing gas exiting the transition chamber from entering the annealing chamber and causing temperature fluctuations and contamination from tin compounds in the gas. Attached Figure Description

[0029] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0030] Figure 2 This is a schematic diagram of the first cross-sectional structure of the present invention;

[0031] Figure 3 This is a schematic diagram of the second cross-sectional structure of the present invention;

[0032] Figure 4 This is a schematic diagram of the front structure of the present invention:

[0033] Figure 5 This is a top view of the structure of the present invention;

[0034] Figure 6 This is a top view of the transition compartment structure of the present invention.

[0035] In the diagram: 1. Solder bath; 2. Solder pan; 3. Transition chamber; 4. Slag box; 5. Cooling mechanism; 6. Annealing chamber; 7. Adjustment mechanism; 8. Buffer chamber; 9. Support roller; 10. Cooling pipe; 11. Heat dissipation ring; 12. Input pipe; 13. Output pipe; 14. Valve; 15. Flow meter; 16. Partition; 17. Graphite strip; 18. Ventilation hole; 19. Pressure strip; 20. Sliding plate; 21. Handle; 22. Transition chamber curtain; 23. Buffer chamber curtain; 24. Annealing chamber curtain; 25. Pressure detection device; 26. Flow rate detection device. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Please see Figures 1-6 The embodiments provided by the present invention are as follows:

[0038] Example: The device includes a solder bath 1, inside which is a molten solder tray 2. A transition chamber 3 is located at one end of the molten solder tray 2, and a slag box 4 is located at the lower end of the transition chamber 3. A cooling mechanism 5 is installed inside the slag box 4. The cooling mechanism 5 reduces the temperature inside the slag box 4, thereby increasing the air pressure inside the slag box 4. A buffer chamber 8 is located at the end of the transition chamber 3 away from the molten solder tray 2, and an adjusting mechanism 7 is located at the upper end of the buffer chamber 8. The adjusting mechanism 7 adjusts the amount of air vented outward from the buffer chamber 8. An annealing chamber 6 is fixedly connected to the end of the buffer chamber 8 away from the transition chamber 3. Support rollers 9 are installed inside the transition chamber 3, the annealing chamber 6, and the buffer chamber 8.

[0039] The cooling mechanism 5 includes multiple cooling pipes 10, each with a fixed heat dissipation ring 11. Both ends of the cooling pipes 10 extend through the transition chamber 3, and an input pipe 12 and an output pipe 13 are fixedly connected to each end. The output pipe 13 inputs cooling water into the cooling pipes 10, thus cooling them and lowering the temperature inside the slag box 4. The heat dissipation rings 11 increase the contact area between the cooling pipes 10 and the air, facilitating temperature regulation.

[0040] A valve 14 is provided at the connection between the cooling pipe 10 and the input pipe 12, and a flow meter 15 is provided at the connection between the cooling pipe 10 and the output pipe 13. The valve 14 and the flow meter 15 are respectively located on both sides of the transition chamber 3. The input pipe 12 and the output pipe 13 are both arranged parallel to the outer wall of the transition chamber 3. The valve 14 and the flow meter 15 can respectively regulate the flow rate in the cooling pipe 10 and detect the flow rate in the cooling pipe 10.

[0041] The transition chamber 3 is provided with multiple partitions 16. The partitions 16 are located at the bottom of the transition chamber 3. The partitions 16 are all arranged on both sides of the cooling pipe 10. Graphite strips 17 are fixedly connected to the top of the partitions 16. The upper end of the graphite strips 17 is in contact with the lower surface of the support roller 9.

[0042] The adjustment mechanism 7 includes a ventilation hole 18 on the upper surface of the buffer chamber 8 near the transition chamber 3, two pressure strips 19 fixedly connected to the upper surface of the ventilation hole 18, and a sliding plate 20 slidably connected below the two pressure strips 19. The sliding plate 20 is adapted to the size of the ventilation hole 18, and a handle 21 is fixedly connected to the upper surface of the sliding plate 20. Adjusting the sliding plate 20 can change the flow rate of the ventilation hole 18.

[0043] A transition chamber curtain 22 is provided above the support roller 9, a buffer chamber curtain 23 is provided between the transition chamber 3 and the buffer chamber 8, and an annealing chamber curtain 24 is provided between the buffer chamber 8 and the annealing chamber 6.

[0044] The bottom of the partition 16 in the transition chamber 3 is equipped with a pressure detection device 25, and the interior of the buffer chamber 8 is equipped with a flow rate detection device 26.

[0045] A Pitot tube is fixedly connected to the flow rate checking device 26.

[0046] The specific operating method is as follows: First, the control method of cooling mechanism 5. Maximize the flow rate of cooling mechanism 5 to reduce the temperature at the bottom of slag box 4, increase the gas density there, and thus increase the pressure. However, considering that excessive cooling intensity will increase the temperature difference between the top and bottom of the glass plate, easily causing defects such as glass plate warping, the flow rate of cooling water in cooling mechanism 5 is adjusted so that the temperature difference between the bottom of the glass plate and when cooling mechanism 5 is not turned on is less than 5°C.

[0047] Part Two: Control Method of Adjustment Mechanism 7. The opening size of the ventilation hole 18 is minimized to increase the gas velocity and thus increase the pressure at the bottom of the slag box 4. However, if the opening of the ventilation hole 18 is too small, the gas from the transition chamber 3 cannot fully exit through this outlet and will enter the annealing chamber 6. This gas contains tin compound particles, which will contaminate the annealing chamber 6. Furthermore, the gas carries a certain temperature, which will affect the stability of the annealing temperature. A flow rate detection device installed in the buffer chamber monitors the amount of gas flowing into the annealing chamber. In actual production, the gas flow rate here is controlled to be less than 1 m / s.

[0048] Test 1: With cooling mechanism 5 off and adjustment mechanism 7 fully open, the pressure at the bottom of slag box 4 was measured to be -2Pa. The temperature at this location was measured to be 230℃ using a portable thermocouple and thermometer. The gas velocity in buffer chamber 8 was <1m / s. At this time, the tin ash accumulation rate at the tail end of tin bath 1 was relatively fast, requiring manual cleaning approximately every three days. After exiting annealing chamber 6, the glass plate showed no warping, and its flatness met product requirements.

[0049] Test 2: With cooling mechanism 5 open and cooling water introduced at a flow rate of 5 m³ / h, and adjustment mechanism 7 fully open, the pressure at the bottom of slag box 4 was measured to be -1 Pa. The temperature at this location was measured to be 210℃ using a portable thermocouple and thermometer. The temperature under the glass plate decreased by 4℃. The gas flow rate in buffer chamber 8 was <1 m / s. At this point, the accumulation rate of tin ash at the tail end of tin bath 1 decreased, requiring manual cleaning approximately every seven days. No warping occurred after the glass plate exited annealing chamber 6, and its flatness met product requirements.

[0050] Test 3: Cooling mechanism 5 is opened, cooling water is introduced at a flow rate of 10 m³ / h, and regulating mechanism 7 is fully open. The pressure at the bottom of slag box 4 is measured to be 0 Pa. The temperature at this location is measured to be 190℃ using a portable thermocouple and thermometer. The temperature under the glass plate drops by 7℃, and the gas flow rate in buffer chamber 8 is <1 m / s. At this point, the accumulation rate of tin ash at the tail end of tin bath 1 decreases, requiring manual cleaning approximately every twenty days. However, due to the large temperature difference between the plate and the bottom, warping occurs after the glass plate exits annealing chamber 6, and the flatness does not meet product requirements.

[0051] Test 4: Cooling mechanism 5 is opened, and cooling water is introduced at a flow rate of 5 m³ / h. Adjustment mechanism 7 is closed by 9 cm, reducing the opening to half its original value. The pressure at the bottom of slag box 4 is measured to be 0 Pa. The temperature at this location is measured to be 210℃ using a portable thermocouple and thermometer. The temperature under the glass plate drops by 4℃. The gas flow rate in buffer chamber 8 is <1 m / s. At this point, the accumulation rate of tin ash at the tail end of tin bath 1 decreases, requiring manual cleaning approximately every twenty days. No warping occurs after the glass plate exits annealing chamber 6, and its flatness meets product requirements.

[0052] Test 5: Cooling mechanism 5 is opened, cooling water is introduced at a flow rate of 5 m³ / h, and adjusting mechanism 7 is closed by 12 cm, reducing the opening to 1 / 3 of its original size. The pressure at the bottom of slag box 4 is measured to be 1 Pa. The temperature at this location is measured to be 210℃ using a portable thermocouple and thermometer. The temperature under the glass plate drops by 4℃, and the gas flow rate in buffer chamber 8 is >1 m / s. At this point, the accumulation rate of tin ash at the tail end of tin bath 1 decreases, requiring manual cleaning approximately every 25 days. After exiting annealing chamber 6, the glass plate shows no warping, and its flatness meets product requirements. However, after approximately 15 days, it is found that there are fallen substances attached to the upper surface of the glass plate, which are tin compounds. Upon opening the side wall of annealing chamber 6, a layer of grayish-white dust is observed attached to the inner wall of buffer chamber 8. Samples are taken and tested, and the composition is also a tin compound, identical to the composition of the fallen substances.

[0053] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A device for reducing molten tin contamination at the tail end of a tin bath, comprising a tin bath (1), characterized in that: The tin bath (1) is provided with a tin liquid tray (2) inside. A transition chamber (3) is provided at one end of the tin liquid tray (2). A slag box (4) is provided at the lower end of the transition chamber (3). A cooling mechanism (5) is provided inside the slag box (4). A buffer chamber (8) is provided at the end of the transition chamber (3) away from the tin liquid tray (2). An adjustment mechanism (7) is provided at the upper end of the buffer chamber (8). An annealing chamber (6) is fixedly connected at the end of the buffer chamber (8) away from the transition chamber (3). Support rollers (9) are provided inside the transition chamber (3), the annealing chamber (6) and the buffer chamber (8). The cooling mechanism (5) includes multiple cooling pipes (10), and multiple heat dissipation rings (11) are fixedly connected to the cooling pipes (10). Both ends of the cooling pipes (10) extend through the transition chamber (3), and the two ends of the extended cooling pipes (10) are respectively fixedly connected to an input pipe (12) and an output pipe (13). The adjustment mechanism (7) includes a ventilation hole (18) on the upper surface of the buffer chamber (8) near the transition chamber (3), two pressure strips (19) fixedly connected to the upper surface of the ventilation hole (18), and a sliding plate (20) slidably connected below the two pressure strips (19). The sliding plate (20) is adapted to the size of the ventilation hole (18), and a handle (21) is fixedly connected to the upper surface of the sliding plate (20).

2. The device for reducing molten tin contamination at the tail end of the tin bath according to claim 1, characterized in that: A valve (14) is provided at the connection between the cooling pipe (10) and the input pipe (12), and a flow meter (15) is provided at the connection between the cooling pipe (10) and the output pipe (13). The valve (14) and the flow meter (15) are respectively located on both sides of the transition chamber (3). The input pipe (12) and the output pipe (13) are both arranged parallel to the outer wall of the transition chamber (3).

3. The device for reducing molten tin contamination at the tail end of the tin bath according to claim 2, characterized in that: The interior of the transition chamber (3) is provided with multiple partitions (16). The partitions (16) are located at the bottom of the transition chamber (3). The partitions (16) are all arranged on both sides of the cooling pipe (10). A graphite strip (17) is fixedly connected above the partition (16). The upper end of the graphite strip (17) is in contact with the lower surface of the support roller (9).

4. The device for reducing molten tin contamination at the tail end of the tin bath according to claim 1, characterized in that: A transition chamber curtain (22) is provided above the support roller (9), a buffer chamber curtain (23) is provided between the transition chamber (3) and the buffer chamber (8), and an annealing chamber curtain (24) is provided between the buffer chamber (8) and the annealing chamber (6).

5. The device for reducing molten tin contamination at the tail end of the tin bath according to claim 3, characterized in that: The bottom of the partition (16) in the transition chamber (3) is equipped with a pressure detection device (25), and the interior of the buffer chamber (8) is equipped with a flow rate detection device (26).

6. The device for reducing molten tin contamination at the tail end of the tin bath according to claim 5, characterized in that: A Pitot tube is fixedly connected to the flow rate checking device (26).

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