A slab film surface cooling device

Abstract

The utility model provides a cast piece film surface cooling device, the air knife subassembly includes first flaps and second flaps, first flaps are in the top of second flaps, first flaps include first air outlet plate and intercepts the board, second flaps include second air outlet plate and follows the board, follows the board and folds down and is equipped with the air intake on the following board, intercepts the board and folds up and forms intercepts the groove, a plurality of air knife subassembly stacks, the following board of air knife subassembly in the top is overlapped in the outside of first air outlet plate or intercepts the groove of air knife subassembly in the bottom. The utility model discloses a cast piece film surface cooling device, through the specific structure design of first flaps and second flaps, can draw off the air intake on the following board in time from the flue gas, intercepts the groove can intercept the condensate on the following board, prevents its fall into the air outlet below and is blown to the film surface by high -speed airflow, effectively avoids the generation of " black point", " bright point " or " white point " and so on appearance defect.

Description

Technical Field

[0001] This utility model relates to the field of casting processing technology, and in particular to a casting film surface cooling device. Background Technology

[0002] In the extrusion casting process of polymer films, after the melt flows from the die, it adheres to the surface of a low-temperature casting roller for cooling, solidification, and crystallization. To enhance the crystallization effect and form a suitable crystal structure for subsequent stretching, a certain cooling rate is required for simultaneous, efficient, and rapid cooling of both sides of the film. During this process, it is essential to ensure uniform cooling on both sides, uniform film thickness, and uniformity in crystallization rate and crystal distribution. During the high-temperature melt cooling process, the introduction of new substances must be prevented. A clean cooling medium and cooling structure with controllable temperature and pressure are recommended to ensure that the cooling medium and heat exchange derivatives do not remain on the casting film surface, causing product defects. Technically and in terms of equipment, a back-cooling fan system with adjustable temperature, pressure, and airflow should typically be installed on the back of the area where the high-temperature melt flows onto the low-temperature casting roller. The back-cooling shroud system uses air knife components to spray high-speed, uniform cooling airflow with controllable temperature and pressure directly onto the surface of the cast film for cooling. During this process, oil fumes and oil-water condensate generated by heat exchange on the high-temperature film surface need to be discharged, and the flue gas needs to be extracted and sent to the purification system for treatment.

[0003] However, in existing casting cooling devices of this type, the cooling airflow emitted by the air knife assembly is typically at a low temperature during long-term use. When encountering humid and hot air or oil vapors from the molten metal, condensation easily forms on the even cooler metal surfaces such as the air knife nozzles and guide plates. These condensed water droplets or oil-water mixtures, carried by the high-speed airflow, may be directly blown onto the not-yet-fully-solidified casting surface, forming persistent defects such as "black spots," "bright spots," or "white spots," severely impacting film quality. Therefore, preventing condensation on the air knives of casting cooling equipment from affecting film quality is a problem that needs to be solved. Utility Model Content

[0004] This invention provides a casting film surface cooling device to solve the above-mentioned problems.

[0005] A casting film surface cooling device includes: an air knife assembly, an air shroud body, and an exhaust system; The air knife assembly includes a first folding plate and a second folding plate. The first folding plate is located above the second folding plate. The first folding plate includes a first air outlet plate and a flow-blocking plate. The second folding plate includes a second air outlet plate and a flow-following plate. The distance between the first air outlet plate and the second air outlet plate gradually decreases to form an air outlet. The flow-following plate is folded downward and has an air intake on it; the flow-cutting plate is folded upward to form a flow-cutting groove; a plurality of air knife assemblies are stacked vertically, with the flow-following plate of the upper air knife assembly overlapping the outside of the first air outlet plate of the lower air knife assembly or inside the flow-cutting groove. The inner cavity of the air shroud is provided with a plurality of air knife assemblies. The two sides of the air shroud are a cooling side and an exhaust side, respectively, and the air outlet of the air knife assembly is located on the cooling side. The air intake is connected to the inner cavity of the hood, and the exhaust system is located on the exhaust side, with the exhaust port of the exhaust system connected to the inner cavity of the hood. The air knife assembly has air inlets on both sides. Cooling air enters the air knife assembly from the air inlets and is blown out from the air outlets. The flue gas on the cooling side enters the inner cavity of the air hood body from the air intake between the air outlets and is discharged from the exhaust port.

[0006] Furthermore, the wind shroud body is provided with a first air inlet cavity and a second air inlet cavity on both sides. The air inlets on both sides of the air knife assembly are connected to the first air inlet cavity or the second air inlet cavity. The first air inlet cavity is located above the second air inlet cavity. The air inlet pipes connected to the first air inlet cavity and the second air inlet cavity are different.

[0007] Furthermore, the air volume of the first air inlet chamber is greater than that of the second air inlet chamber.

[0008] Furthermore, the top of the hood is equipped with an oil fume exhaust device, which is connected to an external oil fume exhaust system.

[0009] Furthermore, a pressure detection device is provided on the hood body, and the pressure detection device is located on the exhaust side.

[0010] Furthermore, a protective plate is provided on the cooling side of the shroud, and the protective plate is located on both sides of the air outlet. The shape of the protective plate is adapted to the shape of the casting roller.

[0011] Furthermore, the hood body is provided with a temperature detection device, which is located above and below the outer side of the inner cavity of the hood body, outside the first air inlet cavity and outside the second air inlet cavity.

[0012] Furthermore, several of the air knife assemblies are stacked one on top of the other, with the angle between the air knife assemblies being greater than or equal to 0° and less than or equal to 90°, and the air outlet direction of the air knife assembly is toward the rotation axis of the casting roller.

[0013] This utility model discloses a casting film cooling device. Through the specific structural design of the first and second folding plates, a gradually narrowing air outlet is formed to ensure the uniformity and speed of the cooling air. The air intake on the flow plate can promptly remove the flue gas. The intercepting groove can intercept the condensate dripping from above, preventing it from falling into the lower air outlet and being blown onto the film surface by the high-speed airflow. The overlapping structure of the upper and lower air knife components ensures the interlayer sealing and structural stability, structurally blocking the path of condensate into the airflow and effectively avoiding the generation of appearance defects such as "black spots," "bright spots," or "white spots." Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the air knife assembly structure disclosed in the embodiments of this utility model; Figure 2 This is a schematic diagram of the structure of the casting film cooling device disclosed in the embodiments of this utility model; Figure 3 This is a front view of the casting film cooling device disclosed in the embodiments of this utility model; Figure 4 for Figure 3 sectional perspective view of the AA position; Figure 5 for Figure 3 sectional perspective view of the middle BB position; Figure 6 for Figure 5 Enlarged view of position C in the middle; Figure 7 This is a schematic diagram of the exhaust side structure of the casting film cooling device disclosed in the embodiments of this utility model.

[0016] In the diagram: 1. Air knife assembly; 11. First folding plate; 111. First air outlet plate; 112. Cut-off plate; 12. Second folding plate; 121. Second air outlet plate; 122. Flow-following plate; 13. Air outlet; 14. Air inlet; 15. Cut-off groove; 16. Air inlet; 2. Fan cover; 21. Cooling side; 22. Exhaust side; 23. First air inlet chamber; 24. Second air inlet chamber; 25. Air inlet duct; 3. Exhaust system; 31. Exhaust vent; 4. Fume extraction device; 5. Pressure detection device; 6. Protective panels; 7. Temperature detection device. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0018] like Figures 1 to 7 As shown, this embodiment provides a casting film surface cooling device for efficient cooling of the casting film surface in the polymer film extrusion casting process, while effectively avoiding contamination of the casting film surface by condensation or oil-water mixture.

[0019] The casting film cooling device in this embodiment mainly includes an air knife assembly 1, an air shroud 2, and an exhaust system 3.

[0020] The air knife assembly 1 includes a first folding plate 11 and a second folding plate 12. The first folding plate 11 is positioned above the second folding plate 12.

[0021] The first baffle 11 includes a first air outlet plate 111 and a flow interceptor plate 112, and the second baffle 12 includes a second air outlet plate 121 and a flow-following plate 122.

[0022] The first air outlet plate 111 and the second air outlet plate 121 are arranged opposite to each other, and the distance between them gradually decreases along the air outlet direction to form a slit-shaped air outlet 13. This tapering structure causes the cooling air to accelerate at the air outlet 13, forming a high-speed and uniform cooling airflow.

[0023] The flow-through plate 122 is located below the second air outlet plate 121, and extends downward to form a flow-guiding structure. An air intake 14 is provided on the flow-through plate 122, which is used to extract the flue gas and any condensate that may be present on the cooling side 21.

[0024] The intercepting plate 112 is located above the first air outlet plate 111 and is folded upward to form an intercepting groove 15. The intercepting groove 15 has a groove-shaped structure and is used to receive the condensate on the upper air knife assembly 1 to prevent the condensate from falling directly to the air outlet 13 of the lower air knife assembly 1.

[0025] When the fumes pass through the air intake 14 on the flow vane 122, oil condenses on the flow vane. The condensed oil flows downwards along the flow vane 122 and is caught by the first exhaust plate 111, preventing it from dripping onto the casting. To further prevent oil accumulation, in this embodiment, the intercepting plate 112 is folded upwards to form an intercepting groove 15, which can store a small amount of oil. At the same time, the oil can flow to both sides along the intercepting groove and be collected and cleaned on both sides, completely eliminating oil contamination of the casting.

[0026] Several air knife assemblies 1 are stacked vertically to form a multi-layer cooling structure. The flow plate 122 of the upper air knife assembly 1 overlaps the outside of the first air outlet plate 111 of the lower air knife assembly 1 or the inside of the intercepting groove 15. This overlapping structure forms an interlayer seal to prevent cooling air leakage between layers, while ensuring the structural stability between each layer of air knife assembly 1.

[0027] The overlap position of the co-flow plate 122 can be selected according to the density of the air knife assembly and the size and angle of the co-flow plate 122. When the co-flow plate 122 overlaps the outside of the first air outlet plate 111, oil can flow into the intercepting groove 15 through the first air outlet plate 111. When the co-flow plate 122 overlaps inside the intercepting groove 15, oil can flow directly into the intercepting groove 15. Different overlap positions allow for more flexible layout and installation of the co-flow plate 122, meeting the needs of more working conditions.

[0028] In this embodiment, when several air knife assemblies 1 are stacked vertically, the air knife assemblies 1 have a certain tilt angle between them. The angle between the air knife assemblies is greater than or equal to 0° and less than or equal to 90°, and can be arranged according to the thickness and density of the air knife assemblies. The air outlet direction of the air knife assembly 1 is towards the rotation axis of the casting roller. This angular arrangement allows the cooling air blown out of the air outlets 13 of each layer to be concentrated on the film surface area of ​​the casting roller, improving cooling efficiency.

[0029] Through the specific structural design of the first folding plate 11 and the second folding plate 12, a gradually narrowing air outlet 13 is formed to ensure the uniformity and speed of the cooling air; the air intake 14 on the flow plate 122 can promptly extract the flue gas; the intercepting groove 15 can intercept the condensate dripping from above, preventing it from falling into the lower air outlet 13 and being blown onto the membrane surface by the high-speed airflow; the overlapping structure of the upper and lower air knife components 1 ensures the interlayer sealing and structural stability, structurally blocking the path of condensate into the airflow, effectively avoiding the generation of appearance defects such as "black spots", "bright spots" or "white spots".

[0030] The air knife components 1 are at a certain angle and the air outlet direction is towards the rotation axis of the casting roller, which allows the multi-layer cooling airflow to converge and act on the film cooling area, improving cooling efficiency and cooling uniformity, and helping to ensure the consistency of double-sided cooling and film thickness.

[0031] The inner cavity of the air hood body 2 is provided with several air knife assemblies 1 as described above. The two sides of the air hood body 2 are a cooling side 21 and an exhaust side 22, respectively. The cooling side 21 is the side facing the object being cooled, and the exhaust side 22 is the side facing away from the object being cooled. The air outlet 13 of the air knife assembly 1 is located on the cooling side 21, blowing cooling air toward the film surface of the casting roller.

[0032] The air intake 14 is connected to the inner cavity of the hood 2. The exhaust system 3 is located on the exhaust side 22, and the exhaust port 31 of the exhaust system 3 is connected to the inner cavity of the hood 2.

[0033] The air knife assembly 1 has air inlets 16 on both sides. Cooling air enters the air knife assembly 1 through the air inlets 16 and is blown out through the air outlets 13. The flue gas from the cooling side 21 (including high-temperature oil fumes generated by melt volatilization and oil fumes generated by heat exchange) enters the inner cavity of the air hood body 2 through the air intake 14 between the air outlets 13, and is discharged from the air outlet 31 under the negative pressure of the exhaust system 3.

[0034] In this embodiment, the exhaust system 3 uses a variable frequency fan, which is connected to the suction hood on the rear side of the hood body 2. The exhaust volume can be adjusted according to the actual working conditions to maintain an appropriate negative pressure inside the hood body 2.

[0035] The air hood 2 integrates the air knife assembly 1 into its inner cavity, forming an airflow circulation with the exhaust system 3: cooling air enters from the air inlet 16, is blown onto the membrane surface through the air outlet 13 for cooling, and the flue gas generated during the cooling process and any trace amounts of condensate that may be carried are drawn into the inner cavity of the air hood 2 through the air intake 14, and finally discharged through the air outlet 31. This "blowing-suction" combined airflow organization method ensures cooling efficiency on the one hand, and timely removes and purifies high-temperature oil fumes and condensate byproducts on the other hand, preventing them from accumulating and falling back inside the equipment, fundamentally reducing the risk of condensate contaminating the membrane surface.

[0036] The wind shroud 2 has a first air inlet chamber 23 and a second air inlet chamber 24 on both sides. The air inlets 16 on both sides of the air knife assembly 1 are respectively connected to the first air inlet chamber 23 or the second air inlet chamber 24.

[0037] The first air inlet chamber 23 is located above the second air inlet chamber 24. The first air inlet chamber 23 and the second air inlet chamber 24 are respectively connected to different air inlet pipes 25, that is, the air inlet pipes 25 of the first air inlet chamber 23 and the second air inlet chamber 24 are independent of each other and can be controlled separately.

[0038] In this embodiment, the air volume of the first air inlet chamber 23 is greater than that of the second air inlet chamber 24. Specifically, the air inlet pipe 25 connected to the first air inlet chamber 23 has a larger diameter or a higher fan power, resulting in a greater cooling air volume supplied to the upper air knife assembly 1 than to the lower air knife assembly 1. This air volume distribution method takes into account that the lower region is closer to the high-temperature molten lava flow zone, and the casting sheet is just beginning to cool and is prone to deformation. Supplying less air to the lower air knife assembly avoids deformation of the casting sheet edges due to a large cooling air volume. After a small amount of cooling, the casting sheet has stronger resistance to deformation, allowing more cooling air to be supplied to the upper first air inlet chamber.

[0039] The use of an independent upper and lower dual air inlet structure allows the air knife assembly 1 at different levels to receive an independent and controllable cooling air supply, which facilitates differentiated adjustment according to the cooling needs of different height areas of the casting roller, thereby improving the flexibility and precision of the cooling process.

[0040] The top of the hood 2 is equipped with an oil fume exhaust device 4. The oil fume exhaust device 4 is connected to an external oil fume exhaust system.

[0041] In this embodiment, the fume extraction device 4 includes a fume collection hood and a connecting pipe. The fume collection hood is located at the top of the hood body 2, and the connecting pipe leads to an external fume purification system. Since high-temperature fumes have the characteristic of rising upwards, the fume extraction device 4 located at the top can capture the rising hot fumes in a timely manner.

[0042] The hood 2 is equipped with a pressure detection device 5. The pressure detection device 5 is located on the exhaust side of the hood 2.

[0043] In this embodiment, the pressure detection device 5 uses a differential pressure sensor, which is installed on the wall of the hood 2 on the exhaust side 22, to monitor the air pressure state of the inner cavity of the hood 2 relative to the external environment in real time.

[0044] A pressure detection device 5 is installed on the exhaust side 22 to monitor the pressure status inside the hood 2 in real time, providing feedback for the airflow adjustment of the exhaust system 3. By maintaining an appropriate negative pressure, the effective extraction of flue gas is ensured, while preventing a large amount of external hot and humid air from seeping in and causing increased condensation on the surface of the air knife, thus achieving a clean cooling environment with controllable pressure.

[0045] The cooling side 21 of the shroud 2 is provided with a protective plate 6. The protective plate 6 is located on both sides of the air outlet 13, and the shape of the protective plate 6 is adapted to the shape of the casting roller.

[0046] In this embodiment, the protective plate 6 is an arc-shaped plate structure with a curvature that matches the outer circumference of the casting roller. The protective plate 6 maintains an appropriate gap (e.g., 5-15mm) with the surface of the casting roller, which neither hinders the rotation of the roller nor prevents the humid and hot air from the external environment from directly entering the air outlet 13 area.

[0047] The protective plate 6 forms a physical barrier on both sides of the air outlet 13, preventing the hot and humid air in the environment from directly contacting the metal surface of the low-temperature air knife, which significantly reduces the possibility of condensation on the surface of the air knife; at the same time, the shape of the protective plate 6 is adapted to the casting roller, ensuring that the cooling airflow can accurately act on the target area of ​​the film surface, thus improving the cooling efficiency.

[0048] The shroud 2 is equipped with a temperature detection device 7. The temperature detection device 7 is located above and below the outer side of the inner cavity of the shroud 2, outside the first air inlet cavity 23, and outside the second air inlet cavity 24.

[0049] In this embodiment, the temperature detection device 7 includes multiple thermocouple temperature sensors, which are respectively arranged on: the upper outer part of the inner cavity of the shroud 2, the lower outer part of the inner cavity of the shroud 2, the outer wall of the first air inlet cavity 23, and the outer wall of the second air inlet cavity 24. Through multi-point temperature monitoring, the temperature distribution of each key area of ​​the equipment can be fully understood.

[0050] Temperature detection device 7 is installed to achieve comprehensive monitoring of the temperature in critical areas of the equipment. Temperature data can be used to promptly identify areas with abnormal temperature rises or condensation risks, providing data support for cooling airflow distribution and exhaust intensity adjustment, ensuring controllable cooling medium temperature, and guaranteeing the safety and stability of the cooling process.

[0051] In this embodiment, when the casting film cooling device is in operation, the cooling air enters each layer of air knife assembly 1 through the air inlet 16 via the first air inlet chamber 23 and the second air inlet chamber 24. After being accelerated by the gradually narrowing air outlet 13, it forms a high-speed uniform airflow, which blows onto the high-temperature film surface of the casting roller for rapid cooling.

[0052] During the cooling process, the oil fumes volatilized from the high-temperature film surface and the oil vapors generated by heat exchange form fumes on the cooling side 21. Part of these fumes are drawn into the inner cavity of the hood body 2 from the air intake 14 between the air outlets 13 under the negative pressure of the exhaust system 3, and discharged through the exhaust port 31; the other part of the rising hot oil fumes are captured and discharged by the top oil fume exhaust device 4.

[0053] To prevent condensation contamination, the device features an upward-folding intercepting plate 112 forming an intercepting groove 15, which can collect any condensate dripping from the top of the upper air knife assembly 1 or the air hood 2, preventing it from falling into the lower air outlet 13. A downward-folding flow plate 122 with an air intake 14 allows the flue gas and any entrained trace amounts of condensate from the cooling side 21 to be promptly removed, preventing it from accumulating on the air knife surface. The overlapping structure of the upper and lower air knife assemblies 1 and the protective plate 6 effectively isolate external humid and hot air, reducing condensation conditions on the metal surface of the air knife. The exhaust system 3 and the fume extraction device 4 form an organized airflow, reducing the retention and condensation of fumes inside the equipment. The pressure detection device 5 and temperature detection device 7 monitor operating parameters in real time, providing a basis for dynamic adjustment of airflow and exhaust volume, maintaining optimal operating conditions, and avoiding the risk of condensation under extreme conditions. Through the synergistic effect of the above structures, the casting film surface cooling device of this embodiment can effectively avoid contamination of the casting film surface by condensation or oil-water mixture while achieving efficient and uniform cooling, thus ensuring the appearance quality and performance consistency of the film products.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A casting film surface cooling device, characterized in that, include: Air knife assembly, air shroud and exhaust system; The air knife assembly includes a first folding plate and a second folding plate. The first folding plate is located above the second folding plate. The first folding plate includes a first air outlet plate and a flow-blocking plate. The second folding plate includes a second air outlet plate and a flow-following plate. The distance between the first air outlet plate and the second air outlet plate gradually decreases to form an air outlet. The flow-following plate is folded downward and has an air intake on it; the flow-cutting plate is folded upward to form a flow-cutting groove; a plurality of air knife assemblies are stacked vertically, with the flow-following plate of the upper air knife assembly overlapping the outside of the first air outlet plate of the lower air knife assembly or inside the flow-cutting groove. The inner cavity of the air shroud is provided with a plurality of air knife assemblies. The two sides of the air shroud are a cooling side and an exhaust side, respectively, and the air outlet of the air knife assembly is located on the cooling side. The air intake is connected to the inner cavity of the hood, and the exhaust system is located on the exhaust side, with the exhaust port of the exhaust system connected to the inner cavity of the hood. The air knife assembly has air inlets on both sides. Cooling air enters the air knife assembly from the air inlets and is blown out from the air outlets. The flue gas on the cooling side enters the inner cavity of the air hood body from the air intake between the air outlets and is discharged from the exhaust port.

2. The casting film cooling device according to claim 1, characterized in that, The wind hood body is provided with a first air inlet cavity and a second air inlet cavity on both sides. The air inlets on both sides of the air knife assembly are connected to the first air inlet cavity or the second air inlet cavity. The first air inlet cavity is located above the second air inlet cavity. The air inlet pipes connected to the first air inlet cavity and the second air inlet cavity are different.

3. The casting film cooling device according to claim 2, characterized in that, The air volume of the first air inlet chamber is greater than that of the second air inlet chamber.

4. The casting film cooling device according to claim 1, characterized in that, The top of the hood is equipped with an oil fume exhaust device, which is connected to an external oil fume exhaust system.

5. The casting film cooling device according to claim 1, characterized in that, The hood is equipped with a pressure detection device, which is located on the exhaust side.

6. The casting film cooling device according to claim 1, characterized in that, The cooling side of the shroud is provided with a protective plate, which is located on both sides of the air outlet. The shape of the protective plate is adapted to the shape of the casting roller.

7. The casting film cooling device according to claim 2, characterized in that, The hood is equipped with a temperature detection device, which is located above and below the outer side of the inner cavity of the hood, outside the first air inlet cavity, and outside the second air inlet cavity.

8. The casting film cooling device according to claim 1, characterized in that, Several air knife assemblies are stacked one on top of the other, with the angle between the air knife assemblies being greater than or equal to 0° and less than or equal to 90°, and the air outlet direction of the air knife assemblies being towards the rotation axis of the casting roller.

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