Hot air circulation device

Abstract

The present invention discloses a hot air circulation device, which is applied to a film stretching machine. The hot air circulation device includes a first air outlet component and a second air outlet component. The first air outlet component and the second air outlet component are arranged opposite to each other and form a heating channel for the film to pass through. The first air outlet component includes a first fan, a first heater and a first cavity. The first cavity is formed with a first air balancing cavity and a plurality of first air outlet holes, and the first fan is connected to the first cavity. The second air outlet component includes a second fan, a second heater and a second cavity. The second cavity is formed with a second air balancing cavity and a plurality of second air outlet holes, and the second fan is connected to the second cavity. Among them, the plurality of first air outlet holes and the plurality of second air outlet holes are arranged opposite to each other and are suitable for being respectively arranged corresponding to the upper surface and the lower surface of the film. The present invention proposes a hot air circulation device, which improves the uniformity of the air outlet, independently controls the air temperature, and adjusts the air volume of the fan.

Description

Technical Field

[0001] The present invention relates to the technical field of film stretching machines, and in particular to a hot air circulation device. Background Art

[0002] Hot air circulation devices are usually used in the baking oven of film transverse stretching machines. Their main function is to control the stretching, shaping and cooling of the film under different temperature environments. It is the key point to control the thickness quality of the film surface.

[0003] In one exemplary technology, a hot air circulation device includes a housing, inner guide rails mounted within the housing, an insulation layer mounted outside the housing, and outer guide rails mounted outside the insulation layer. The housing is equipped with a fan, heater, air duct, air duct connecting plate, and protective cover. However, the housing has a convex structure. Driven by the fan, air flows within the housing's air duct, resulting in poor uniformity in air velocity and pressure, significantly affecting the quality of film stretching. Summary of the Invention

[0004] The main purpose of the present invention is to provide a hot air circulation device, aiming to improve the uniformity of air output and thus improve the quality of film stretching.

[0005] To achieve the above objectives, the present invention provides a hot air circulation device, which is applied to a film stretching machine, wherein the film stretching machine is provided with a baking oven, and the hot air circulation device is installed in the baking oven. The hot air circulation device includes a first air outlet component and a second air outlet component, wherein the first air outlet component and the second air outlet component are arranged opposite to each other and form a heating channel for the film to pass through;

[0006] The first air outlet assembly includes a first fan, a first heater, and a first cavity. The first cavity is formed with a first air balancing cavity for uniform wind speed and pressure and a plurality of first air outlet holes connected to the first air balancing cavity. The air outlet and air inlet of the first fan are connected to the first cavity. The first heater is provided in the first cavity and is used to change the air temperature.

[0007] The second air outlet assembly includes a second fan, a second heater, and a second cavity. The second cavity is formed with a second air balancing cavity for uniform wind speed and pressure and a plurality of second air outlet holes connected to the second air balancing cavity. The air outlet and air inlet of the second fan are connected to the second cavity. The second heater is provided in the second cavity and is used to change the air temperature.

[0008] The plurality of first air outlet holes and the plurality of second air outlet holes are arranged opposite to each other and are adapted to be arranged corresponding to the upper surface and the lower surface of the film respectively.

[0009] Optionally, the first air outlet assembly further includes a first filter, which is arranged between the air outlet end of the first fan and the first air equalizing cavity to filter particulate matter in the air.

[0010] Optionally, the second air outlet assembly further includes a second filter, which is arranged between the air outlet end of the second fan and the second air equalizing cavity to filter particulate matter in the air.

[0011] Optionally, the first air equalizing cavity and the second air equalizing cavity both include a first-level energy storage static pressure cavity and a second-level energy storage static pressure cavity connected to the first-level energy storage static pressure cavity; an air equalizing mesh plate is provided in the first cavity and the second cavity, and the air equalizing mesh plate divides the first-level energy storage static pressure cavity into two sub-first-level energy storage static pressure cavities and divides the second-level energy storage static pressure cavity into two sub-second-level energy storage static pressure cavities.

[0012] Optionally, the cross-sectional width of the first-stage energy storage static pressure chamber presents a trend of first being constant and then gradually decreasing in a direction approaching the film.

[0013] Optionally, the secondary energy storage static pressure chamber is arranged in a "concave" shape.

[0014] Optionally, the first cavity and the second cavity are both provided with air supply ports adapted to admit fresh air. Optionally, the first cavity and the second cavity are both provided with air return ports adapted to communicate with the inner cavity of the oven.

[0015] Optionally, the first cavity includes a first air outlet cavity and a first air return cavity that are spaced apart from each other, the first air outlet cavity is connected to the air outlet end of the first fan, and the first air return cavity is connected to the air inlet end of the first fan, the first air outlet cavity and the first air return cavity are both formed with the first air balancing cavity and the first air outlet hole, and the inner cavity width of the first return air cavity is arranged to decrease in a step-like manner from the direction away from the first fan;

[0016] The second cavity includes a second air outlet cavity and a second air return cavity that are spaced apart from each other. The second air outlet cavity is connected to the air outlet end of the second fan, and the second air return cavity is connected to the air inlet end of the second fan. The second air outlet cavity and the second air return cavity are both formed with a second air balancing cavity and a second air outlet hole. The inner cavity width of the second return air cavity is arranged to decrease in a step-like manner from the direction away from the second fan.

[0017] Among them, a plurality of first strip openings evenly spaced along the length direction are provided on the opposite sides of the first return air cavity and the second return air cavity, and a plurality of second strip openings evenly spaced along the length direction are provided on the other side of the first return air cavity and the second return air cavity, and the plurality of first strip openings and the plurality of second strip openings constitute the return air opening.

[0018] Optionally, the first air outlet assembly further includes a first temperature sensor, which is installed in the first cavity and connected to the first heater, so as to detect the air temperature in the first cavity;

[0019] The second air outlet assembly further includes a second temperature sensor, which is installed in the second cavity and connected to the second heater to detect the air temperature in the second cavity.

[0020] In the technical solution of the present invention, the hot air circulation device includes a first air outlet component and a second air outlet component. The first air outlet component and the second air outlet component are arranged opposite to each other and form a heating channel for the film to pass through. The first air outlet component includes a first fan, a first heater and a first cavity. The first cavity is formed with a first air balancing cavity for uniform wind speed and wind pressure and a plurality of first air outlet holes connected to the first air balancing cavity. The air outlet end and the air inlet end of the first fan are connected to the first cavity. The first heater is arranged in the first cavity and is used to change the air temperature. The second air outlet component includes a second fan, a second heater and a second cavity. The second cavity is formed with a second air balancing cavity for uniform wind speed and wind pressure and a plurality of second air outlet holes connected to the second air balancing cavity. The air outlet end and the air inlet end of the second fan are connected to the second cavity. The second heater is arranged in the second cavity and is used to change the air temperature. Among them, the plurality of first air outlet holes and the plurality of second air outlet holes are arranged opposite to each other and are suitable for being arranged corresponding to the upper surface and the lower surface of the film respectively.

[0021] It can be understood that since the first cavity is provided with a first air balancing cavity for uniform wind speed and wind pressure, and the second cavity is provided with a second air balancing cavity for uniform wind speed and wind pressure, the uniformity of the air outlet is improved, the temperature of the upper and lower surfaces of the film is more uniform, and the quality of the film stretching is improved.

[0022] In addition, the first and second chambers of the hot air circulation device are equipped with independent heaters, which can be adjusted by temperature sensors to achieve controllable air outlet temperature. Furthermore, the circulating fan adopts variable frequency control, which can be used to adjust the frequency and control the air volume on the membrane surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0024] Figure 1 This is a schematic structural diagram of an embodiment of a hot air circulation device of the present invention;

[0025] Figure 2 A front view of an embodiment of a hot air circulation device of the present invention;

[0026] Figure 3 for Figure 2 Cross-sectional view at AA in the middle;

[0027] Figure 4 for Figure 2 Cross-sectional view at the middle BB;

[0028] Figure 5 for Figure 2 Cross-sectional view at CC;

[0029] Figure 6 for Figure 2 Cross-sectional view at DD in the middle;

[0030] Figure 7 for Figure 2 Cross-sectional view at EE;

[0031] Figure 8 for Figure 7 A cross-sectional view of the first air outlet assembly;

[0032] Figure 9 This is a schematic structural diagram of the first air outlet cavity in one embodiment of the hot air circulation device of the present invention;

[0033] Figure 10 for Figure 9 Structural diagram of the ventilation hole between the first-stage and second-stage static pressure energy storage chambers;

[0034] Figure 11 for Figure 9 Structural diagram of the air outlet of the first air outlet cavity.

[0035] Description of Figure Numbers:

[0036] 10. First air outlet component; 20. Second air outlet component; 100a. Heating channel; 100. Film; 11. First fan; 12. First heater; 13. First cavity; 14. First filter; 101a. First air equalizing cavity; 101b. First air outlet; 21. Second fan; 22. Second heater; 23. Second cavity; 24. Second filter; 102a. Second air equalizing cavity; 102b. Second air outlet; 10a1. Primary energy storage static pressure cavity; 10a2. Second energy storage static pressure cavity; 15. Air equalizing mesh plate; 101c. Air supply port; 101d. Return air port; 131. First air outlet cavity; 132. First return air cavity; 231. Second air outlet cavity; 232. Second return air cavity; 101e. Ventilation hole.

[0037] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0040] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if the meaning of "and / or" appearing in the full text is to include three parallel schemes, taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] The present invention provides a hot air circulation device, which is applicable to a film stretching machine, etc., but is not limited here.

[0042] In one embodiment of the present invention, the film stretching machine used by the hot air circulation device is provided with a baking oven, and the hot air circulation device is installed in the baking oven. Figures 1 to 5 The hot air circulation device includes a first air outlet assembly 10 and a second air outlet assembly 20. The first air outlet assembly 10 and the second air outlet assembly 20 are arranged opposite each other and form a heating channel 100a for the film 100 to pass through. The first air outlet assembly 10 includes a first fan 11, a first heater 12, and a first cavity 13. The first cavity 13 is formed with a first air balancing cavity 101a for uniform wind speed and wind pressure and a plurality of first air outlet holes 101b connected to the first air balancing cavity 101a. The air outlet and air inlet ends of the first fan 11 are connected to the first cavity 13. The first heater 12 is disposed in the first cavity 13 and is used to change the air temperature. The second air outlet assembly 20 includes a second fan 21, a second heater 22, and a second cavity 23. The second cavity 23 is formed with a second air balancing cavity 102a for uniform wind speed and pressure, and a plurality of second air outlet holes 102b connected to the second air balancing cavity 102a. The air outlet and air inlet of the second fan 21 are connected to the second cavity 23. The second heater 22 is located in the second cavity 23 and is used to change the air temperature. The plurality of first air outlet holes 101b and the plurality of second air outlet holes 102b are arranged opposite each other and are respectively arranged on the upper and lower surfaces of the film 100.

[0043] In this embodiment, both the first heater 12 and the second heater 22 may be PTC heaters, etc., which is not limited here.

[0044] It should be noted that both the first cavity 13 and the second cavity 23 can be box structures, and their specific size and shape can be designed according to the internal structure of the baking oven of the film stretching machine and the specifications of the film 100 product, and are not specifically limited here. Figure 2 In this embodiment, the first cavity 13 and the second cavity 23 are both provided with a return air port 101d adapted to communicate with the inner cavity of the baking oven.

[0045] In order to improve production efficiency and make the air flow more uniform, it is better to refer to Figures 1 to 4 、 Figure 11 The first cavity 13 may include a first air outlet cavity 131 and a first air return cavity 132 arranged at intervals. The first air outlet cavity 131 is connected to the air outlet end of the first fan 11, and the first return air cavity 132 is connected to the air inlet end of the first fan 11. The first air outlet cavity 131 and the first return air cavity 132 are both formed with a first air balancing cavity 101a and a first air outlet hole 101b. The inner cavity width of the first return air cavity 132 is arranged to decrease in a step-like manner from the direction away from the first fan 11.

[0046] Correspondingly, the second cavity 23 may also include a second air outlet cavity 231 and a second air return cavity 232 arranged at intervals. The second air outlet cavity 231 is connected to the air outlet end of the second fan 21, and the second return air cavity 232 is connected to the air inlet end of the second fan 21. The second air outlet cavity 231 and the second return air cavity 232 are both formed with a second air balancing cavity 102a and a second air outlet hole 102b. The inner cavity width of the second return air cavity 232 is arranged to decrease in a step-like manner from the direction away from the second fan 21.

[0047] refer to Figure 2 、 Figure 5 and Figure 6 The opposing sides of the first and second return air cavities 132 and 232 each have multiple first strip-shaped openings spaced evenly along the length. The other sides of the first and second return air cavities 132 and 232 each have multiple second strip-shaped openings spaced evenly along the length. These multiple first and second strip-shaped openings constitute the return air vent 101d. This improves the uniformity of the return air volume.

[0048] The return air box design structure of the hot air circulation device adopts a gradient design, the purpose of which is to achieve a gradient distribution of return air pressure in an overly long return air cavity, achieve uniformity of return air, and avoid the phenomenon of uneven return air due to the excessive length of the return air cavity.

[0049] The first air balancing cavity 101a and the second air balancing cavity 102a may each include a plurality of sub-cavities, in which an air balancing mesh plate 15 or a guide plate may be provided, and the plurality of first air outlet holes 101b and the plurality of second air outlet holes 102b may be evenly spaced to achieve the function of uniform air outlet.

[0050] It can be understood that since the first cavity 13 is provided with a first air balancing cavity 101a for uniform wind speed and pressure, and the second cavity 23 is provided with a second air balancing cavity 102a for uniform wind speed and pressure, the uniformity of the air output is improved, the temperature of the upper and lower surfaces of the film 100 is more uniform, and the stretching quality of the film 100 is improved.

[0051] Furthermore, the first and second cavities 13 and 23 of the hot air circulation device are equipped with independent heaters, which can be adjusted via temperature sensors to achieve controllable air outlet temperature. Furthermore, the circulating fan utilizes variable frequency control, enabling control of airflow across the film 100 surface through frequency regulation. This thermal circulation device is large in size and length, with a high air outlet speed, making it suitable for high-speed film stretching equipment, effectively controlling the uniformity of film surface thickness.

[0052] In order to improve the cleanliness of the air and prevent particles or impurities in the air from being blown onto the surface of the film 100 and affecting the product quality, the main reference is Figure 1 and Figure 2 In one embodiment, the first air outlet assembly 10 may further include a first filter 14. The first filter 14 is disposed between the air outlet end of the first fan 11 and the first air equalizing cavity 101a to filter particulate matter in the air.

[0053] In this embodiment, the second air outlet assembly 20 may further include a second filter 24. The second filter 24 is disposed between the air outlet end of the second fan 21 and the second air equalizing cavity 102a to filter particulate matter in the air.

[0054] In this embodiment, the first filter 14 and the second filter 24 can both adopt coal-catalyst filters and high-precision filter screens to effectively filter particulate matter and precipitates in the hot air, thereby achieving internal circulating air to achieve purification.

[0055] refer to Figure 7 and Figure 8 In this embodiment, both the first and second air balancing chambers 101a, 102a include a primary energy storage static pressure chamber 10a1 and a secondary energy storage static pressure chamber 10a2 connected to the primary energy storage static pressure chamber 10a1. Air balancing mesh plates 15 are installed within the first and second cavities 13, 23. These divide the primary energy storage static pressure chamber 10a1 into two primary sub-cavities and the secondary energy storage static pressure chamber 10a2 into two secondary sub-cavities. Each of the two secondary sub-cavities can be independently equipped with two exhaust holes to improve air uniformity. The entire device achieves excellent air balancing through multiple air balancing cycles.

[0056] The heat circulation device of the present invention circulates the air in the stretching machine baking box internally, reducing energy consumption; internal air circulation is carried out in a closed and heat-insulating baking box, and through the internal circulation of the upper and lower cavities, the fan draws the air inside the baking box into the return air cavity through the return air port 101d, and flows into the cavity through the heater, the fan volute, and the precision filter in turn, and then blows out uniform air with a certain temperature through the air outlet, thereby achieving the effect of heating, cooling and shaping the film surface of the film 100.

[0057] refer to Figure 8 In this embodiment, the cross-sectional width of the first-stage energy storage static pressure chamber 10a1 is constant at first and then gradually decreases in the direction close to the film 100. The second-stage energy storage static pressure chamber 10a2 is arranged in a "concave" shape. The first-stage energy storage static pressure chamber 10a1 is partially embedded in the second-stage energy storage static pressure chamber 10a2. The two oblique sides of the box body constituting the first-stage energy storage static pressure chamber 10a1 can be provided with connecting holes to communicate with the second-stage energy storage static pressure chamber 10a2, or the two top sides of the box body constituting the second-stage energy storage static pressure chamber 10a2 can be provided with multiple ventilation holes 101e to communicate with the first-stage energy storage static pressure chamber 10a1, such as Figures 8 to 10 shown.

[0058] The first cavity 13 and the second cavity 23 of the present invention realize uniform air outlet through the internal structure design. The wind output from the air outlet of the fan is evenly distributed through the multi-stage distribution of the cavity: release wind pressure → evenly distribute to the double chambers → compress air → release air. Specifically: in the first stage, the air is blown from the air outlet of the fan to the filter for filtering; in the second stage, the filtered wind enters the two sub-first-level energy storage static pressure chambers of the first-level energy storage static pressure chamber 10a1 for uniform treatment; in the third stage, the air is evenly distributed through the wind-equalizing mesh plate 15 in the middle of the two sub-first-level energy storage static pressure chambers; in the fourth stage, the evenly distributed wind enters the second-level energy storage static pressure chamber 10a2 under the action of gravity to compress the air; in the fifth stage, the compressed wind is blown to the surface of the film 100 through the air outlet.

[0059] Main references Figure 2 In one embodiment, both the first cavity 13 and the second cavity 23 are provided with an air supply port 101c suitable for introducing fresh air.

[0060] It should be noted that the air inside the oven is constantly circulating, and this air contains a large amount of diluents, which may contaminate the film surface 100. Replacing the air inside the oven by supplying fresh air can effectively improve the quality of the film 100. In this embodiment, the return air cavity is provided with a supply air port 101c for supplying fresh air. Before entering, the fresh air is heated to prevent temperature fluctuations inside the oven. During supply air, the air is exhausted through the oven's exhaust port.

[0061] To improve the precise control of the outlet air temperature, enhance the heating effect, and thus improve the stretching quality of the film 100, in some embodiments, the first outlet assembly 10 may further include a first temperature sensor, which is installed in the first cavity 13 and connected to the first heater 12, for detecting the air temperature in the first cavity 13. The second outlet assembly 20 may further include a second temperature sensor, which is installed in the second cavity 23 and connected to the second heater 22, for detecting the air temperature in the second cavity 23.

[0062] In this embodiment, the number of the first temperature sensor and the second temperature sensor can be multiple, and thermistors and the like can be used, but are not limited here.

[0063] The above descriptions are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present description and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A hot air circulation device, applied to a film stretching machine, wherein the film stretching machine is provided with a baking oven, and the hot air circulation device is installed in the baking oven, characterized in that: The hot air circulation device includes a first air outlet component and a second air outlet component, wherein the first air outlet component and the second air outlet component are arranged opposite to each other and form a heating channel for the film to pass through; The first air outlet component includes a first fan, a first heater, a first cavity and a first filter, the first cavity forming a first air balancing cavity for uniform wind speed and pressure and a plurality of first air outlet holes connected with the first air balancing cavity, the air outlet end and the air inlet end of the first fan are connected with the first cavity, the first heater is arranged in the first cavity and is used to change the air temperature, the first filter is arranged between the air outlet end of the first fan and the first air balancing cavity for filtering particulate matter in the air; the first cavity includes a first air outlet cavity and a first return air cavity arranged at intervals, the first air outlet cavity is connected with the air outlet end of the first fan, the first return air cavity is connected with the air inlet end of the first fan, the first air outlet cavity and the first return air cavity are both formed with the first air balancing cavity and the first air outlet holes, and the inner cavity width of the first return air cavity is arranged to decrease in a step-like manner from the direction away from the first fan; The second air outlet assembly includes a second fan, a second heater and a second cavity, the second cavity is formed with a second air balancing cavity for uniform wind speed and pressure and a plurality of second air outlet holes connected to the second air balancing cavity, the air outlet end and the air inlet end of the second fan are connected to the second cavity, the second heater is arranged in the second cavity and is used to change the air temperature; the second cavity includes a second air outlet cavity and a second air return cavity arranged at intervals, the second air outlet cavity is connected to the air outlet end of the second fan, the second air return cavity is connected to the air inlet end of the second fan, the second air outlet cavity and the second return air cavity are both formed with the second air balancing cavity and the second air outlet holes, and the inner cavity width of the second return air cavity is arranged to decrease in a step-like manner from the direction away from the second fan; In which, the first cavity and the second cavity are both provided with an air supply port suitable for introducing fresh air and a return air port suitable for communicating with the inner cavity of the baking oven; multiple first air outlet holes and multiple second air outlet holes are arranged opposite to each other and are suitable for being arranged corresponding to the upper surface and lower surface of the film respectively; multiple first strip openings are opened on the opposite sides of the first return air cavity and the second return air cavity, and multiple second strip openings are opened on the other sides of the first return air cavity and the second return air cavity, which are evenly spaced along the length direction. The multiple first strip openings and the multiple second strip openings constitute the return air port.

2. The hot air circulation device according to claim 1, wherein The second air outlet assembly further includes a second filter, which is arranged between the air outlet end of the second fan and the second air equalization cavity to filter particulate matter in the air.

3. The hot air circulation device according to claim 1, wherein The first air equalizing cavity and the second air equalizing cavity both include a first-level energy storage static pressure cavity and a second-level energy storage static pressure cavity connected to the first-level energy storage static pressure cavity; an air equalizing mesh plate is provided in the first cavity and the second cavity, and the air equalizing mesh plate divides the first-level energy storage static pressure cavity into two sub-first-level energy storage static pressure cavities and divides the second-level energy storage static pressure cavity into two sub-second-level energy storage static pressure cavities.

4. The hot air circulation device according to claim 3, wherein: The cross-sectional width of the first-level energy storage static pressure cavity shows a trend of first being constant and then gradually decreasing in a direction approaching the film.

5. The hot air circulation device according to claim 4, wherein: The secondary energy storage static pressure chamber is arranged in a "concave" shape.

6. The hot air circulation device according to claim 1, wherein: The first air outlet assembly further includes a first temperature sensor, which is installed in the first cavity and connected to the first heater to detect the air temperature in the first cavity; The second air outlet assembly further includes a second temperature sensor, which is installed in the second cavity and connected to the second heater to detect the air temperature in the second cavity.

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