Method for controlling drawing amount in photovoltaic glass production

Abstract

The invention provides a method for controlling the drawing amount in photovoltaic glass production, which is characterized by comprising the following steps of: arranging a flame blocking brick at a melting overflow port, reducing an open area on the outer side of the overflow port, and increasing the temperature of glass; an upper roller and a lower roller of the calender are different in rotating speed, a set of auxiliary rollers, a set of transition rollers and an annealing roller are sequentially distributed on one side of the upper roller and one side of the lower roller, and the auxiliary rollers, the transition rollers and the annealing roller are different in rotating speed. The control mode is simple, the implementation is convenient, the temperature of the glass liquid before entering the press rollers of the calender is increased, the speed control among the rollers is easier, the glass plate can stretch the glass more easily, the thickness of the glass is more uniform, the load of the calender is reduced, and the operation safety of the equipment is protected.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic glass production, and specifically to a method for controlling the drawing rate in the production of photovoltaic glass. Background Art

[0002] The glass drawing rate refers to adjusting the thickness of the glass by stretching the glass during the glass manufacturing process. Stretching the glass means heating the glass plate to a semi-molten state and then stretching it on a calender, thereby deforming the glass plate and reducing its thickness. By controlling the stretching speed and stretching ratio during the stretching process, the thickness of the glass plate can be precisely controlled. This is very important for glass manufacturing and processing because the thickness of the glass has a very important impact on its performance and uses.

[0003] With the rapid iteration and update of the photovoltaic industry, as an important auxiliary material, photovoltaic glass is moving forward in the direction of ultra-thin and lightweight. To cope with the market changes, the original glass production line of the company, which produced glass with a specification of 2.0 mm, needs to be completely changed to produce 1.6 mm. Technologically, when producing glass with a specification of 1.6 mm, the difficulty of thickness control is much greater than that of 2.0 mm. Secondly, the calender applies pressure at both ends, and the thickness in the middle is more difficult to control than at the edges, resulting in an increase in the thickness difference. The uneven thickness of the glass will inevitably cause an increase in the drawing rate. The maximum melting capacity of the melting furnace is 550 tons per day. When three production lines produce 1.6 mm glass, the drawing rate exceeds 570 tons per day, and the melting capacity of the melting furnace cannot reach the required level, which affects the service life and production of the furnace. Summary of the Invention

[0004] The present invention is to overcome the deficiencies in the prior art and provide a method for controlling the drawing rate in the production of photovoltaic glass.

[0005] The present application provides the following technical solutions: A method for controlling the drawing rate in the production of photovoltaic glass, characterized in that it includes: arranging a flame baffle brick at the melting overflow port to reduce the open area outside the overflow port and raise the glass temperature to 1050°C - 1060°C; the upper and lower rollers of the calender have different rotation speeds, and a set of auxiliary rollers, a set of transition rollers, and annealing rollers are sequentially distributed on one side of the upper and lower rollers, and the rotation speeds of the auxiliary rollers, transition rollers, and annealing rollers are different.

[0006] Based on the above technical solutions, the following further technical solutions may be available: The rotation speeds of the upper roller, lower roller, auxiliary roller, transition roller, and annealing roller are set to increase.

[0007] The thickness of the photovoltaic glass after passing through the annealing roller is 1.63 mm - 1.75 mm.

[0008] The pressures received by the end surfaces of the two ends of the upper roller are different.

[0009] The rotational speed of the lower roller is 2% - 8% faster than that of the upper roller, the rotational speed of the auxiliary roller is 1% - 15% faster than that of the lower roller, the rotational speed of the transition roller is 5% - 20% faster than that of the auxiliary roller, and the rotational speed of the annealing roller is 20% - 35% faster than that of the transition roller.

[0010] Advantages of the invention: The control method of the present invention is simple and easy to implement. By adding a baffle brick in front of the overflow port of the melting furnace, the open area between the melting furnace and the calender is reduced, the heat dissipation rate of the molten glass is decreased, and thus the temperature of the molten glass before entering the calender rollers is increased. This makes it easier to control the speed between each roller, enables the glass plate to stretch the glass more easily, ensures that the thickness of the glass is more uniform, and also reduces the load on the calender, protecting the safe operation of the equipment. Description of the drawings

[0011] Figure 1 It is a schematic diagram of the distribution of each roller in the drawing-in device of the present invention. Detailed implementation manners Embodiment

[0012] As Figure 1 shown, a method for controlling the drawing rate in the production of photovoltaic glass includes: installing a baffle brick 1 on the outer wall of the glass melting furnace above the outer side of the melting overflow port of the glass melting furnace. By means of the baffle brick 1, the area of the open area between the melting furnace and the calender is reduced, the heat dissipation rate of the molten glass 3 is decreased, and the temperature of the molten glass before entering the calender rollers is increased to 1050°C.

[0013] The roller diameter of the upper roller 4 of the calender is a convex roller of 315 mm ± 5 mm, and the roller diameter of the lower roller 5 is a patterned roller of 320 mm ± 5 mm. A set of auxiliary rollers 6, a set of transition rollers 7, and an annealing roller 8 are sequentially distributed on one side of the upper and lower rollers 4 and 5. The horizontal height of the set of auxiliary rollers 6 gradually decreases, while the set of transition rollers 7 and the annealing roller 8 are horizontally distributed.

[0014] The speed of the upper roller is controlled at 7 - 7.4 m / min, the speed of the lower roller is controlled at 7.5 - 7.9 m / min, the speed of the auxiliary roller is controlled at 7.7 - 8.9 m / min, the speed of the movable roller is controlled at 9.2 - 10 m / min, and the speed of the annealing roller is controlled at 11.5 - 13 m / min.

[0015] Calculate the speed ratios between each roller as follows: Speed ratio between the upper roller and the lower roller: (V lower - V upper) / V lower * 100% = 5.94% (the rotational speed of the lower roller is 5.94% faster than that of the upper roller); Speed ratio between the lower roller and the auxiliary roller: (V auxiliary - V lower) / V auxiliary * 100% = 1.69% (the rotational speed of the auxiliary roller is 1.69% faster than that of the lower roller); Auxiliary roller and transition roller speed ratio: (V_trans - V_aux) / V_trans * 100% = 16.65% (The transition roller rotates 16.65% faster than the auxiliary roller); Transition roller and annealing roller speed ratio: (V_anneal - V_trans) / V_anneal * 100% = 28.85% (The annealing roller rotates 28.85% faster than the transition roller).

[0016] The pressure at one end of the upper roller pressing bar 2 of the calender is 6921 kg, and the other end is 6002 kg. The width of the glass plate is controlled at 2400 mm. After annealing and cutting, the finished glass is obtained. The average thickness from the left side to the right side is measured to be 1.71 mm, and the drawing amount is 192.07 T / d. Example

[0017] In Examples 1 and 2, the overall structure of the equipment remains unchanged, the temperature of the overflow port and the roller diameters of the upper and lower rollers of the calender remain unchanged. Adjust the speeds of the new upper and lower rollers, auxiliary rollers, movable rollers, and annealing rollers, and recalculate the speed ratios between the rollers for adjustment. The specific values are as follows: Upper roller and lower roller speed ratio: (V_lower - V_upper) / V_lower * 100% = 3.29% (The lower roller rotates 3.29% faster than the upper roller); Lower roller and auxiliary roller speed ratio: (V_aux - V_lower) / V_aux * 100% = 8.10% (The auxiliary roller rotates 8.10% faster than the lower roller); Auxiliary roller and transition roller speed ratio: (V_trans - V_aux) / V_trans * 100% = 16.88% (The transition roller rotates 16.88% faster than the auxiliary roller); Transition roller and annealing roller speed ratio: (V_anneal - V_trans) / V_anneal * 100% = 23.46% (The annealing roller rotates 23.46% faster than the transition roller).

[0018] The pressure at one end of the upper roller pressing bar 2 of the calender is 5563 kg, and the other end is 4929 kg. The width of the original plate is controlled at 2400 mm. After annealing and cutting, the finished glass is obtained. The average thickness from the left side to the right side is measured to be 1.69 mm, and the drawing amount is 189.82 T / d. Example

[0019] In Examples 1 and 3, the overall structure of the equipment remains unchanged, the temperature of the overflow port and the roller diameters of the upper and lower rollers of the calender remain unchanged. Adjust the speeds of the new upper and lower rollers, auxiliary rollers, movable rollers, and annealing rollers, and recalculate the speed ratios between the rollers for adjustment. The specific values are as follows: Upper roller and lower roller speed ratio: (V_lower - V_upper) / V_lower * 100% = 5.26% (The lower roller rotates 5.26% faster than the upper roller); Lower roller and auxiliary roller speed ratio: (V_aux - V_lower) / V_aux * 100% = 11.11% (The auxiliary roller rotates 11.11% faster than the lower roller); Auxiliary roller and transition roller speed ratio: (V_trans - V_aux) / V_trans * 100% = 8.06% (The rotational speed of the transition roller is 8.06% faster than that of the auxiliary roller); Transition roller and annealing roller speed ratio: (V_anneal - V_trans) / V_anneal * 100% = 26.77% (The rotational speed of the annealing roller is 26.77% faster than that of the transition roller).

[0020] The pressure at one end of the upper roller of the pressing bar 2 on the calender is 5940 kg, and the other end is 5982 kg. The width of the original plate is controlled at 2400 mm. After annealing and cutting, the finished glass is obtained. The average thickness from the left side to the right side is measured to be 1.65 mm, and the drawing rate is 181.05 T / d.

[0021] Statistically analyze the forming experimental parameters and glass parameters of Examples 1 - 3. The parameters obtained in Example 1 mainly show that it is difficult to press the thickness by relying on the pressure of the pressing bar of the calender, and the equipment load is relatively large (the operating load of the pressing bar of the experimental calender is about 7000 kg); The parameters of Example 2 mainly show that it is difficult to control the thickness difference of the glass by controlling the forming with a large speed ratio; the parameters of Example 3 show that better glass can be obtained by combining the pressure of the upper roller pressing bar and the speed ratio, and the equipment load is also within the safe range.

[0022] As mentioned above, the experimental results only obtain the preferred specific implementation manners of the present invention under the existing equipment and conditions of the company. However, the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A method for controlling the pulling amount in photovoltaic glass production, characterized in that It includes: A flame-blocking brick is arranged at the melting overflow port to reduce the opening area outside the overflow port and increase the glass temperature to 1050°C-1060°C; the rotation speeds of the upper and lower rollers (4, 5) of the calender are different; a group of auxiliary rollers (6), a group of transition rollers (7) and an annealing roller (8) are sequentially arranged on one side of the upper and lower rollers (4, 5); the rotation speeds of the auxiliary rollers (6), the transition rollers (7) and the annealing rollers (8) are different.

2. A method for controlling the pulling amount in photovoltaic glass production according to claim 1, characterized in that: The rotation speeds of the upper roller (4), the lower roller (5), the auxiliary roller (6), the transition roller (7) and the annealing roller (8) are set to be accelerated.

3. A method for controlling the pulling amount in photovoltaic glass production according to claim 1, characterized in that: After passing through the annealing roller (8), the thickness of the photovoltaic glass is 1.63 mm to 1.75 mm.

4. A method for controlling the pulling amount in photovoltaic glass production according to claim 1, characterized in that: The pressures exerted on the roller surfaces at both ends of the upper roller (4) are different.

5. A method for controlling the pulling amount in photovoltaic glass production according to claim 2, characterized in that: The rotation speed of the lower roller (5) is 2%-8% faster than the rotation speed of the upper roller (4); the rotation speed of the auxiliary roller (6) is 1%-15% faster than the rotation speed of the lower roller (5); the rotation speed of the transition roller (7) is 5%-20% faster than the rotation speed of the auxiliary roller (6); and the rotation speed of the annealing roller is 20%-35% faster than the rotation speed of the transition roller (7).

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