Transverse temperature difference control device for glass plates in glass annealing kiln and use method

Abstract

The invention relates to a transverse temperature difference control device for glass plates in a glass annealing kiln and a using method, the transverse temperature difference control device comprises a pulley assembly and a partition plate assembly, the pulley assembly is located at the top of the annealing kiln, the partition plate assembly is in sliding connection with the pulley assembly, and the partition plate assembly and the pulley assembly cooperate to divide the interior of the annealing kiln into a plurality of subareas; the partition plate assembly comprises heat preservation cotton and a partition plate, the partition plate is a hollow rectangular steel plate component, and the heat preservation cotton is located in a steel plate. The annealing furnace has the advantages that the interior of the annealing furnace is partitioned by arranging the partition plate assembly, mutual interference between cooling air systems in the annealing furnace is avoided, after partitioning, especially the edge temperature of a glass plate is easier to control, it can be guaranteed that the transverse temperature in the whole annealing furnace is kept stable, and the glass production quality is improved.

Description

Technical Field

[0001] This invention belongs to the field of annealing furnace technology, specifically relating to a device for controlling the transverse temperature difference of glass plates in a glass annealing furnace and its usage method. Background Technology

[0002] An annealing furnace is an industrial device used after glass forming to appropriately control the rate of temperature reduction, keeping the thermal stress in the glass within an acceptable range. The core function of a float glass annealing furnace is to permanently eliminate internal stress by precisely controlling the cooling rate of the glass during its transport from the tin bath to the cold end. The main structure of an annealing furnace includes a shell, an electric heating system, a cooling air system, conveyor rollers, and a control system.

[0003] Ideally, glass production involves the glass sheet passing sequentially through the insulated and open zones of an annealing furnace at a set temperature to complete the annealing process. However, due to radiation and convection heat transfer between the glass sheet's two edges and components such as the furnace's inner plates, the heat dissipation area is much larger than that of the glass sheet's center. This results in heat loss from the edges of the glass sheet being much faster than from the center, creating a temperature distribution pattern of "cold edges and hot center." Heat from the glass sheet also dissipates through rollers and the cooling air system. Since heat loss through rollers is difficult to control, annealing furnaces are designed with the cooling air system grouped to regulate the lateral temperature difference of the glass sheet.

[0004] However, in float annealing furnaces, when the glass thickness is large and the heat in the center of the glass sheet is much greater than that at the edges, or when the glass sheet width becomes narrow and the edges dissipate heat too quickly, many production lines experience situations where the edge temperature of the glass sheet remains low even when the edge cooling air system is completely shut down. To meet production needs, many manufacturers have to use electric heating to compensate for the temperature at the glass sheet edges. This increases energy consumption and control complexity, hindering automation.

[0005] Therefore, there is an urgent need for a method that can overcome the above-mentioned defects, thereby reducing the problem of excessive lateral temperature difference in float glass annealing furnaces. Summary of the Invention

[0006] The present invention aims to solve the problem of difficulty in controlling the transverse temperature difference in existing float glass annealing furnaces.

[0007] The present invention solves the above-mentioned technical problems through the following technical means: A transverse temperature difference control device for glass plates inside a glass annealing furnace includes a pulley assembly and a partition plate assembly. The pulley assembly is located at the top of the annealing furnace, and the partition plate assembly is slidably connected to the pulley assembly. The partition plate assembly and the pulley assembly work together to divide the interior of the annealing furnace into multiple zones. The partition plate assembly includes insulation cotton and a partition plate. The partition plate is a hollow rectangular steel plate component, and the insulation cotton is located inside the steel plate.

[0008] This invention divides the interior of the annealing furnace into partitions by setting up partition plate components, which avoids mutual interference between the cooling air systems inside the annealing furnace. After partitioning, the temperature of the glass plate edges is easier to control, which can ensure that the transverse temperature inside the entire annealing furnace remains stable and improves the quality of glass production.

[0009] Preferably, the partition panel assembly further includes an upper hanging plate, which consists of two sets, each set including two L-shaped steel plates. The sum of the widths of the shorter sides of the two L-shaped steel plates is less than the width of the partition panel. The upper hanging plates are located on the top two sides of the partition panel, forming a "door" shape with a groove in the middle.

[0010] The design of the upper hanging panel facilitates the installation and removal of the partition panel.

[0011] Preferably, the pulley assembly includes a connecting plate, which comprises multiple pieces and is welded to the top of the annealing furnace. The width of the connecting plate matches the size of the reserved groove on the upper hanging plate.

[0012] Preferably, the pulley assembly further includes multiple pairs of pulley groups, each pair of pulley groups being fixed to the lower part of the connecting plate by a pin, the distance between each pair of pulley groups being less than the width of the partition plate, and the pulley groups being able to slide freely inside the upper hanging plate.

[0013] The pulley system not only facilitates the installation of partition panels, but also provides rolling to accommodate the expansion of the partition panels due to heat.

[0014] Preferably, the partition panel assembly includes various sizes, and the selection of the size of the partition panel assembly is related to the size of the glass plate processed in the annealing furnace.

[0015] The variety of partition plate assemblies provides more options for controlling the internal temperature stability of the annealing furnace.

[0016] Preferably, it also includes a cooling air system, which comprises multiple sets and is located at the top of the annealing furnace.

[0017] Preferably, it also includes a temperature control system, which includes multiple sets of thermocouples, multiple sets of electric heating components, and an infrared meter. The thermocouples and infrared meter are located at the top of each cooling air system, and the electric heating components are located on both sides of the annealing furnace.

[0018] Preferably, the cooling air system includes a pneumatic butterfly valve, which controls the opening degree of the cooling air system.

[0019] Preferably, the method also includes a method for using a transverse temperature difference control device for glass plates inside a glass annealing furnace. The method includes: firstly, welding a pulley assembly to the top of the annealing furnace between the first and second cooling air systems on both sides; secondly, selecting a suitable partition plate assembly based on experience and suspending it on the pulley assembly to divide the annealing furnace into zones; then conducting preliminary tests, observing the temperature of each zone inside the annealing furnace using thermocouples and infrared instruments, controlling the airflow of the cooling air system with pneumatic butterfly valves, and simultaneously adjusting the power of the electric heating components until the transverse temperature in each zone stabilizes and meets the production standards of the annealing furnace; finally, determining the parameters and starting formal production.

[0020] Preferably, if adjusting the pneumatic butterfly valve and electric heating assembly fails to achieve lateral temperature stability, the partition plate model is adjusted, and a preliminary test is conducted again. The pneumatic butterfly valve and electric heating assembly are adjusted until lateral temperature stability is achieved, meeting the production standards of the annealing kiln. Once all parameters are determined, formal production can begin.

[0021] The advantages of this invention are: (1) By setting up a partition plate assembly, the present invention divides the interior of the annealing furnace into partitions, avoiding mutual interference between the cooling air systems inside the annealing furnace. After partitioning, the temperature at the edge of the glass plate is easier to control, ensuring that the transverse temperature inside the entire annealing furnace remains stable and improving the quality of glass production. (2) The design of the upper hanging plate facilitates the installation and disassembly of the partition board; (3) The pulley system not only facilitates the installation of the partition, but also provides rolling to cope with the expansion of the partition due to heat. (4) Multiple types of partition plate assemblies provide more options for controlling the internal temperature stability of the annealing furnace. Attached Figure Description

[0022] Figure 1 This is a diagram showing the transverse temperature gradient of glass plates under natural cooling conditions inside a traditional annealing furnace. Figure 2 This diagram illustrates the transverse temperature gradient of glass plates inside a conventional annealing furnace when the side cooling air system is closed. Figure 3 This is a front view of the transverse temperature difference control device for the glass plate inside the annealing furnace in Embodiment 1; Figure 4 This is a side view of the transverse temperature difference control device for the glass plate inside the annealing furnace in Embodiment 1. Figure 5This is a schematic diagram showing the location of the transverse temperature difference control device for the glass plate inside the annealing furnace in Example 1. Figure 6 This is a diagram showing the lateral temperature gradient of the glass plate in Example 1, which uses a lateral temperature difference control device for the glass plate inside the annealing furnace.

[0023] Numbering on the map: 1. Partition panel assembly; 11. Partition panel; 12. Insulation cotton; 13. Upper hanging panel; 2. Pulley assembly; 21. Connecting plate; 22. Pulley block; 3. Cooling air system; 31. Cooling fan; 32. Pneumatic butterfly valve; 4. Temperature control components; 41. Electric heating components; 42. Thermocouples. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0025] Combination Figures 1-2 As shown, in traditional float glass annealing furnaces, the theoretical goal is for the glass sheets to sequentially pass through the holding and open zones of the furnace at a set temperature to complete the annealing process. By precisely controlling the cooling rate, the internal stress of the glass is permanently eliminated. This is under natural cooling conditions. (See also...) Figure 1 As shown, because the two edges of the glass plate undergo radiation and convection heat transfer with components such as the inner plate of the furnace, the heat dissipation area is much larger than that of the middle of the glass plate. This results in the heat loss rate at the edges of the glass plate being much faster than that in the middle, thus forming a temperature distribution pattern of "cold edges and hot middle." To ensure the quality of the glass annealing stage, float glass annealing furnaces generally use a cooling air system installed at the top of the annealing furnace. The initial design goal was to control the cooling air volume at the edges and middle of the glass plate, increasing the air volume in the high-temperature middle area and decreasing the air volume in the low-temperature edge area, thereby maintaining a stable transverse temperature of the glass plate throughout the annealing furnace. However, in practical applications, when the glass thickness is large and the heat in the middle of the glass plate is much greater than that at the edges, or when the glass plate width becomes narrow and the heat dissipation at the edges is too fast, many production lines experience situations where the edge temperature of the glass plate remains low even when the edge cooling air system is completely shut down. (See also...) Figure 2As shown, even if the cooling air system at the edge is completely shut off and the cooling air system in the middle is fully turned on, the convection of the cooling air in the middle will indirectly reduce the temperature at the edge of the glass plate. As a result, the transverse temperature of the entire glass plate is still difficult to stabilize, which makes it difficult to guarantee the production quality of the glass plate.

[0026] Example 1: This embodiment provides a transverse temperature difference control device for glass plates inside a glass annealing furnace, including a partition plate assembly 1 and a pulley assembly 2. The pulley assembly 2 is welded to the top of the annealing furnace, the partition plate assembly 1 is slidably connected to the pulley assembly 2, the cooling air system 3 is installed on the top of the annealing furnace, and the temperature control assembly 4 is located above the cooling air system 3 and on both sides of the annealing furnace. For details, please refer to Figure 3 The partition panel assembly 1 includes a partition panel 11, insulation cotton 12, and an upper hanging plate 13. The partition panel 11 is a hollow rectangular plate-shaped component composed of six steel plates, made of heat-resistant steel with a low coefficient of thermal expansion. The length of the partition panel 11 is determined according to the length of the annealing furnace, the height ensures that the distance between the bottom and the glass plate after installation is not less than 50mm, and the thickness is approximately 50mm. Various models of the partition panel 11 are available, with differences in thickness and length between different models. The insulation cotton 12 fills the interior of the partition panel 11. To ensure the actual effect of the partition panel assembly 1, the insulation cotton 12 is generally made of ceramic fiber, with a filling density of 150kg / m³. 3 (Other filling materials or materials that meet the requirements may also be selected). Each partition panel assembly 1 comprises two sets of upper hanging panels 13, located at the front and rear tops of the partition panel 11, respectively. See reference. Figure 3 and Figure 4 Each set of upper hanging plates 13 includes two L-shaped steel plates of a certain length. The sum of the widths of the shorter sides of the two L-shaped steel plates is less than the width of the partition plate 11. The two L-shaped steel plates are inverted, and their long sides are welded to the steel plates of the partition plate 11. The shorter sides of the two inverted L-shaped steel plates are opposite each other, forming a groove.

[0027] See Figure 3 and Figure 4 The pulley assembly 2 includes a connecting plate 21 and a pulley block 22. The connecting plate 21 is a rectangular plate-shaped component, its length being less than the length of the upper hanging plate 13, and its width being less than the width of the groove formed by the upper hanging plate 13. One end of the connecting plate 21 is fixed to the top of the annealing furnace and is located between two cooling fans 31; its number and position are consistent with the upper hanging plate 13. Each partition plate assembly 1 includes two pulley blocks 22, and each pulley block 22 includes two pulleys. (See reference...) Figure 3 and Figure 4The pulley block 22 consists of two pulleys and a bearing that passes through the connecting plate 21. The two pulleys are located on both sides of the connecting plate 21 and can rotate via the bearing. In use, the sliding groove of the upper hanging plate 13 of the partition plate assembly 1 is aligned with the connecting plate 21, and the partition plate assembly 1 is hung on the connecting plate 21. The pulley block 22 can be locked inside the upper hanging plate 13, and the partition plate assembly 1 can slide within a certain range via the pulley block 22, reducing the difficulty of installing the partition plate assembly 1. Moreover, the pulley block 22 provides a certain rolling friction for the partition plate assembly 1. When the partition plate assembly 1 expands due to heat, the partition plate assembly 1 and the pulley block 22 roll relative to each other, which can counteract the displacement caused by the thermal expansion.

[0028] See Figure 5 The cooling air system 3 includes cooling air ducts 31 and pneumatic butterfly valves 32. The cooling air ducts 31 consist of four groups (the specific number varies depending on the size of the annealing furnace; it can be four, six, eight, etc.). The cooling air ducts 31 are evenly distributed at the top of the annealing furnace. A partition plate assembly 1 is arranged between the first and second groups of cooling air ducts 31, and between the third and fourth groups. The partition plate assembly 1 horizontally divides the entire interior of the annealing furnace into three areas. The pneumatic butterfly valve 32 is located at the air inlet of each group of cooling air ducts and is used to individually control each group of cooling air ducts 31 and adjust the airflow of the cooling air ducts 31.

[0029] See Figure 5 The temperature control assembly 4 includes an electric heating assembly 41 and a thermocouple 42. The electric heating assembly 41 is located on both sides of the annealing furnace and extends to the edge of the glass plate, its function being to provide supplemental heating to the edge of the glass plate. The thermocouple 42 is installed at the cooling fan 31, its function being to measure the temperature of the area corresponding to each cooling fan 31.

[0030] Combination Figures 5-6 As shown, the method of using the device of this application is as follows: When annealing a batch of glass, the transverse temperature difference control device for the glass plates in the float glass annealing furnace of this application is first assembled. Using machinery, the partition plate 11 is lifted to the position of the connecting plate 21, the groove of the upper hanging plate 13 is aligned with the connecting plate 21, and the partition plate 11 is installed using the pulley block 22. The various devices on the production line are then started for a preliminary test. Based on the temperature feedback from the thermocouple 42 and the infrared meter, the electric heating component 41 and the pneumatic butterfly valve 32 are adjusted until the temperature inside the annealing furnace is adjusted to a transversely stable state. The parameters at this point are recorded for later use. Large-scale mass production is only permitted after the preliminary test is completed. If the pre-test adjustment of the pneumatic butterfly valve 32 and thermocouple 42 fails to achieve the target transverse temperature difference, a different model of partition plate component 1 is tried, and adjustments are continued until the transverse temperature difference of the glass plates inside the annealing furnace meets the production requirements. When the model of the glass plate requiring annealing changes, the partition plate component 1, the pneumatic butterfly valve 32, and the electric heating component 41 need to be readjusted.

[0031] See Figure 6 After using the device of this application, the low temperature at the edge of the glass plate was significantly improved.

[0032] This invention divides the interior of the annealing furnace into zones by setting up a partition plate assembly 1, avoiding mutual interference between the cooling air systems inside the annealing furnace. After partitioning, the temperature of the glass plate edges is easier to control, ensuring that the lateral temperature inside the entire annealing furnace remains stable and improving the quality of glass production. The design of the upper hanging plate 13 facilitates the installation and removal of the partition plate 11; the pulley group 22 not only facilitates the installation of the partition plate 11 but also provides rolling to cope with the expansion of the partition plate 11 due to heat; the multiple models of the partition plate assembly 1 provide more options and combinations for controlling the stable temperature inside the annealing furnace.

[0033] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Terms such as "upper," "lower," "left," "right," "front," and "rear" used in the invention are merely for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0034] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for controlling the transverse temperature difference of glass plates in a glass annealing furnace, characterized in that, The furnace includes a pulley assembly and a partition plate assembly. The pulley assembly is located at the top of the annealing furnace, and the partition plate assembly is slidably connected to the pulley assembly. The partition plate assembly and the pulley assembly work together to divide the interior of the annealing furnace into multiple zones. The partition plate assembly includes insulation cotton and a partition plate. The partition plate is a hollow rectangular steel plate component, and the insulation cotton is located inside the steel plate.

2. The transverse temperature difference control device for glass plates in a glass annealing furnace according to claim 1, characterized in that, The partition panel assembly also includes an upper hanging plate, which consists of two sets, each set including two L-shaped steel plates. The sum of the widths of the shorter sides of the two L-shaped steel plates is less than the width of the partition panel. The upper hanging plates are located on the top two sides of the partition panel, forming a "door" shape with a groove in the middle.

3. The transverse temperature difference control device for glass plates in a glass annealing furnace according to claim 2, characterized in that, The pulley assembly includes a connecting plate, which comprises multiple pieces and is welded to the top of the annealing kiln. The width of the connecting plate matches the reserved groove size of the upper hanging plate.

4. The transverse temperature difference control device for glass plates in a glass annealing furnace according to claim 3, characterized in that, The pulley assembly also includes multiple pairs of pulley groups, each pair of pulley groups is fixed to the lower part of the connecting plate by a pin, the distance between each pair of pulley groups is less than the width of the partition plate, and the pulley groups are located inside the upper hanging plate and slide freely.

5. The transverse temperature difference control device for glass plates in a glass annealing furnace according to claim 1, characterized in that, The partition panel assembly includes various sizes, and the selection of the size of the partition panel assembly is related to the size of the glass plate processed in the annealing furnace.

6. The transverse temperature difference control device for glass plates in a glass annealing furnace according to claim 1, characterized in that, It also includes a cooling air system, which comprises multiple sets and is located at the top of the annealing furnace.

7. The transverse temperature difference control device for glass plates in a glass annealing furnace according to claim 1, characterized in that, It also includes a temperature control system, which comprises multiple sets of thermocouples, multiple sets of electric heating components, and an infrared meter. The thermocouples and infrared meter are located at the top of each cooling air system, and the electric heating components are located on both sides of the annealing furnace.

8. The transverse temperature difference control device for glass plates in a glass annealing furnace according to claim 6, characterized in that, The cooling air system includes a pneumatic butterfly valve, which controls the opening degree of the cooling air system.

9. A method of using the transverse temperature difference control device for glass plates in a glass annealing furnace according to any one of claims 1 to 8, characterized in that, First, a pulley assembly is welded to the top of the annealing furnace, located between the first and second cooling air systems on both sides. Next, based on experience, a suitable partition plate assembly is selected and suspended from the pulley assembly to divide the annealing furnace into zones. Then, preliminary tests are conducted, using thermocouples and infrared thermometers to observe the temperature of each zone within the annealing furnace. Pneumatic butterfly valves are controlled to adjust the cooling air system, and the electric heating components are adjusted until the transverse temperature in each zone stabilizes and meets the production standards for float glass annealing furnaces. Finally, all parameters are determined, and formal production begins.

10. The method of using the transverse temperature difference control device for glass plates in a glass annealing furnace according to claim 9, characterized in that, If adjusting the pneumatic butterfly valve and electric heating assembly fails to achieve lateral temperature stability, adjust the partition plate model, conduct another preliminary test, and adjust the pneumatic butterfly valve and electric heating assembly until lateral temperature stability is achieved, meeting the annealing kiln production standards. Once all parameters are determined, formal production can begin.

Images