Drying oven structure of casting machine

Abstract

The utility model discloses a drying oven structure of a casting machine, which comprises an upper drying tunnel and a lower drying tunnel, the upper drying tunnel is provided with a first temperature zone, a parallel air circulation processing device is arranged in the first temperature zone, and the parallel air circulation processing device comprises at least one group of parallel air duct air inlet part and parallel air duct air outlet part which are oppositely arranged; and the parallel air duct air inlet part and the parallel air duct air outlet part are arranged above and below the steel belt, or are only independently arranged above the steel belt. According to the drying oven structure of the casting machine, different treatment areas are divided according to the moving path of a film, different treatment modes are adopted, and when film slurry just enters the drying channel, the parallel air channels are adopted to blow preheating air, so that the surface of the film slurry begins to be hardened, and air flow is ensured; the hot air is prevented from directly blowing towards the film surface of the film slurry to influence the film quality; and hot air can be blown in a manner of directly facing the film surface subsequently, so that the efficiency and effect of heating and evaporating the solvent are ensured.

Description

Technical Field

[0001] This utility model belongs to the field of casting machine technology, and specifically relates to an oven structure for a casting machine. Background Technology

[0002] A casting machine is a type of thin film manufacturing equipment. Existing technologies include, for example, Chinese invention patent application publication number CN117754794A. However, this patent does not explicitly describe the air outlet method of the static pressure chamber. The basic principle of the casting machine's oven is to use hot air to initially dry the film slurry on the steel belt, causing solvent evaporation and the film to begin hardening. The specific hot air outlet method affects film quality, especially for high-end films. For example, existing ovens typically outlet air from the side of the steel belt containing the film slurry; direct airflow may affect the uniformity of the slurry and cause the steel belt to vibrate or sag. Therefore, a novel casting machine oven structure is needed to further improve film quality. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide an oven structure for a casting machine, which solves the problem that the air outlet method of the existing solution may affect the uniformity of the film slurry. By improving the air outlet method, the desired drying effect can be achieved while ensuring the quality of the film, especially for high-end film processes such as polyimide film.

[0004] According to the technical solution of this utility model, this utility model provides an oven structure for a casting machine, including an upper drying tunnel and a lower drying tunnel. A first temperature zone is provided in the upper drying tunnel, and a parallel air circulation treatment device is provided in the first temperature zone. The parallel air circulation treatment device includes at least one set of parallel air duct inlet and parallel air duct outlet arranged opposite to each other. The parallel air duct inlet and parallel air duct outlet are arranged above and below the steel strip, or are arranged only above the steel strip.

[0005] Furthermore, the air inlet and outlet of the parallel air duct are equipped with flow equalization plates and / or air regulating plates; wherein, the flow equalization plates are provided with a number of air holes or a number of slit holes.

[0006] Furthermore, the air outlet of the parallel air duct is located near the entrance of the upper drying duct, and the air inlet of the parallel air duct is located on the opposite side of the air outlet of the parallel air duct.

[0007] Furthermore, the upper and lower drying tunnels include several temperature zones using a longitudinal air circulation system, each of which is an adjustable temperature zone.

[0008] Furthermore, an active roller temperature zone is provided on one side of the upper and lower drying tunnels, and a passive roller temperature zone is provided on the other side. The passive roller temperature zone is equipped with a far-infrared heating device or a ceramic heating device.

[0009] Furthermore, partitions are installed at the adjacent locations of the two temperature zones and at the entrances and exits of the upper and lower drying tunnels. The partitions have a connecting opening in the middle, and a negative pressure air curtain device is installed at the connecting opening. The negative pressure air curtain device includes a first exhaust section and a second exhaust section arranged opposite to each other. A channel space for the steel belt to pass through is formed between the first exhaust section and the second exhaust section. The width of the channel space is adapted to the width of the film.

[0010] Furthermore, both the first exhaust section and the second exhaust section are located on the air curtain static pressure box, and both the first exhaust section and the second exhaust section are equipped with air curtain flow equalization plates and / or air regulating plates.

[0011] Furthermore, the oven body has an oven exhaust vent located near the side partitions and / or on the side wall of the oven body parallel to the partitions.

[0012] Furthermore, an air inlet is provided on the side wall of the box perpendicular to the partition.

[0013] Furthermore, explosion vents are provided in the first temperature zone and / or other temperature zones of the upper drying tunnel.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0015] In the oven structure of this casting machine, different processing zones are divided according to the film's movement path, and different processing methods are adopted. When the film slurry just enters the drying tunnel, preheating air is blown through parallel air ducts to harden the surface of the film slurry and ensure airflow, while avoiding hot air directly blowing onto the film surface, which could affect film quality. Subsequently, hot air is blown directly onto the film surface to ensure the efficiency and effectiveness of heating and solvent evaporation. Furthermore, this design preferably places the exhaust vent in a specific dead corner to better discharge the solvent and avoid solvent gas accumulation, which could lead to recondensation and dripping onto the film or cause potential combustion or explosion. Furthermore, this solution preferably incorporates a negative pressure air curtain device, in which two oppositely positioned exhaust vents simultaneously draw air, each equipped with an air curtain flow equalization plate to ensure uniform airflow intensity. A negative pressure air curtain is formed in the channel space between the two exhaust vents, allowing the film to be transmitted between the two spaces. Because of the negative pressure air curtain between these two spaces, issues such as temperature and gas interaction (e.g., escape / cross-contamination of gases with different temperatures and compositions) are avoided, effectively ensuring the accuracy and stability of process environment control for high-end processes. Attached Figure Description

[0016] Figure 1 This is a cross-sectional structural schematic diagram of a casting machine according to an embodiment of the present invention.

[0017] Figure 2 yes Figure 1The diagram shows a top view of the casting machine in the embodiment shown.

[0018] Figure 3 This is a three-dimensional structural diagram of a negative pressure air curtain device according to an embodiment of the present utility model.

[0019] Figure 4 yes Figure 3 The rear view of the negative pressure air curtain device in the embodiment shown is a schematic diagram.

[0020] Figure 5 yes Figure 3 The left view of the negative pressure air curtain device in the embodiment shown is a schematic diagram.

[0021] Explanation of reference numerals in the attached figures:

[0022] 1. Upper drying tunnel; 2. Lower drying tunnel; 3. Parallel air box; 31. Parallel air duct outlet; 32. Parallel air duct inlet; 4. Nozzle-type static pressure box; 5. Negative pressure air curtain device; 51. First exhaust section; 52. Second exhaust section; 53. Air curtain flow equalization plate; 54. Channel space; 55. Channel side plate; 56. Slit baffle; 57. First airtight air box; 58. Second airtight air box; 59. First exhaust pipe; 510. Second exhaust pipe; 61. Oven exhaust port; 62. Oven inlet; 63. Explosion vent; 71. Active rotating drum; 72. Passive rotating drum; 81. Active rotating drum chamber; 82. Passive rotating drum chamber. Detailed Implementation

[0023] This invention provides an oven structure for a casting machine, which solves the problem that the air outlet method of the existing solution may affect the uniformity of the film slurry. By improving the air outlet method, it can ensure the film quality while achieving the required drying effect, especially for high-end film processes such as polyimide films.

[0024] Please see Figure 1 , Figure 2 The casting machine includes an active drum 71, a passive drum 72, and a steel belt that drives the drums. The steel belt is located inside an oven, which has an upper drying channel 1 and a lower drying channel 2 corresponding to the steel belt, thereby drying the film slurry on the steel belt. This type of casting machine is existing technology and will not be described in detail here. In the oven structure of a casting machine according to an embodiment of the present invention, a first temperature zone is provided in the upper drying channel 1, and a parallel air circulation treatment device is provided in the first temperature zone. The first temperature zone is preferably located at the inlet of the upper drying channel 1. The parallel air circulation treatment device includes at least one set of parallel air duct inlet 32 ​​and parallel air duct outlet 31 arranged opposite to each other. The parallel air duct inlet 32 ​​and parallel air duct outlet 31 are arranged above and below the steel belt, or only above the steel belt.

[0025] A parallel air circulation treatment device is located at least above the steel belt (the film slurry is also located above the steel belt in this area). The parallel air circulation treatment device is used to blow preheating air in a direction generally parallel to the steel belt. In this embodiment, in the remaining part of the upper drying tunnel 1 and the lower drying tunnel 2, a nozzle-type static pressure box 4 is provided at least on the outer side of the steel belt, and the nozzle of the nozzle-type static pressure box 4 faces the steel belt (i.e., towards the film).

[0026] Taking polyimide film as an example, a mixer is used to uniformly mix the main material, polyamic acid resin, and the auxiliary material, imidizing agent. Then, the mixed slurry is output from the mold at the discharge end of the mixer onto the steel belt at the active drum 71 of the casting machine. The slurry moves, heats, evaporates the solvent, and gradually begins to solidify into a film as the steel belt rotates. Finally, after nearly one revolution, it is peeled off from the steel belt at the active drum 71 by a peeling roller; this process continues. Specifically, using… Figure 1 For example, the film slurry first drips onto the upper right of the annular steel belt. Then, as the steel belt moves counterclockwise, it first enters the area of ​​the parallel air circulation treatment device. This area is used for preheating and pre-evaporation, and to give the film surface a certain hardness. The parallel air duct method is used to ensure airflow in this area, allowing the surface of the film slurry (wet film) to begin to harden, while avoiding direct hot air blowing onto the film surface. Subsequently, the film enters the area with the nozzle-type static pressure box 4. At this point, the film surface is hard enough to withstand the hot air. Hot air is then blown roughly directly onto the film surface to transfer heat more directly and efficiently and accelerate solvent evaporation.

[0027] The parallel air circulation treatment device preferably adopts a static pressure box structure. Both the parallel air duct inlet 32 ​​and the parallel air duct outlet 31 are located on the parallel air box 3. A parallel air duct flow equalization plate and / or air regulating plate are provided within the parallel air duct inlet 32 ​​and the parallel air duct outlet 31 to ensure the uniformity of the parallel airflow and preheating effect. Furthermore, it can be optionally equipped with adjustable wind speed or direction. More specifically, the parallel air duct flow equalization plate is, for example, a perforated flat plate, and the air regulating plate is, for example, a grid. The parallel air duct flow equalization plate is provided with several air holes or several slits. The parallel air duct flow equalization plate can be configured as multiple layers, with the air holes or slits in each layer arranged opposite to or staggered. In some embodiments, the air vents are, for example, small holes arranged closely on the flow equalization plate; in other embodiments, the air vents are arranged strip-shaped holes, or the flow equalization plate is grid-shaped or mesh-shaped; or it is a combination of multiple hole types; the slit hole is a long and narrow slit-shaped hole, for example, one or more slit holes, and the length direction of the slit hole is, for example, parallel to the width direction of the film or inclined at a certain angle.

[0028] Parallel airflow is used in the first temperature zone because the membrane has not yet formed. Parallel airflow is used to reduce the impact of wind speed on the appearance quality of the unformed membrane.

[0029] In a preferred embodiment, in the parallel air circulation processing device, the parallel air duct outlet 31 is located near the inlet of the upper drying tunnel 1; the parallel air duct inlet 32 ​​is located on the opposite side of the parallel air duct outlet 31, that is, relatively far from the inlet of the upper drying tunnel 1. The parallel air flows in the opposite direction to the movement of the film slurry, ensuring the airflow velocity above the film slurry in a relatively gentle and stable manner, which helps the film surface to harden.

[0030] Preferably, a parallel air circulation treatment device is also provided below the steel belt, and the flow rate, direction, and other parameters of the parallel air on both the upper and lower sides are optionally consistent. This preheats the steel belt and the other side of the film, improving temperature uniformity and heating efficiency. Furthermore, since there is airflow on both the upper and lower sides of the steel belt, it effectively avoids the problem of uneven stress on both sides causing local bending of the steel belt, which would affect the quality of the film.

[0031] Similarly, it is preferable to also provide a nozzle-type static pressure box 4 on the inner side of the steel strip. The nozzle-type static pressure boxes 4 on the inner and outer sides of the steel strip are arranged in groups opposite each other so that the impact of hot air on the upper and lower sides is basically offset. If the nozzle-type static pressure box 4 blows directly onto the steel strip, the bending of the steel strip under force will be more obvious if it is only located on one side.

[0032] Please see Figure 1 More preferably, the upper drying tunnel 1 and the lower drying tunnel 2 include several temperature zones using a longitudinal air circulation treatment device. Each temperature zone is an adjustable temperature zone (temperature adjusted by a blower or static pressure box). The temperature zones are divided in the direction from the inlet to the outlet of the upper drying tunnel 1 and the lower drying tunnel 2. The longitudinal air circulation treatment device is, for example, a nozzle-type static pressure box 4, used to blow air directly onto the film surface. The temperature zones include a first temperature zone in the upper drying tunnel 1, which is the area where the film just enters the steel strip casting machine and has not yet formed a film. The parallel air circulation treatment device is set in the first temperature zone. Multiple (or groups of) nozzle-type static pressure boxes 4 are arranged side by side in the direction from the inlet to the outlet. Each (or group of) nozzle-type static pressure box 4 corresponds to one temperature zone, thereby forming multiple (five in the illustrated embodiment) temperature zones in the direction from the inlet to the outlet. The parallel air circulation treatment devices and nozzle-type static pressure boxes 4 in different temperature zones are relatively independent and can be set with different hot air temperatures as needed to control the temperature of each temperature zone separately.

[0033] Furthermore, partitions are installed at the adjacent locations of the two temperature zones and at the entrances and exits of the upper drying tunnel 1 and the lower drying tunnel 2. Each partition has a connecting opening in the middle, and a negative pressure air curtain device 5 is sealed and connected at the connecting opening. A partition is also installed between the upper drying tunnel 1 and the lower drying tunnel 2. This creates a temperature and air isolation effect between the various temperature zones, preventing uncontrollable mutual interference caused by gas diffusion between the temperature zones. The negative pressure air curtain device 5 includes a first exhaust section 51 and a second exhaust section 52 arranged opposite to each other. The first exhaust section 51 and the second exhaust section 52 are used for simultaneous exhaust. A channel space 54 is formed between the first exhaust section 51 and the second exhaust section 52 for the steel belt to pass through. The width of the channel space 54 is adapted to the width of the film (and the steel belt), specifically, the width covers the film and is generally greater than or equal to the width. Essentially, the steel belts in each temperature zone of the oven can only pass through the channel space 54 (connecting port), while the rest is sealed. When the airflow flows towards the partition between adjacent spaces, it is drawn away by the first exhaust fan 51 and the second exhaust fan 52 on the upper and lower sides, thus preventing the airflow from entering adjacent spaces. Especially for polyimide films, it is necessary to ensure that the evaporated solvent (flammable gas) is discharged from the oven in a timely manner, to ensure solvent evaporation efficiency, and to prevent the solvent from escaping into other temperature zones or spaces, such as to prevent excessive solvent content in high-temperature zones from causing combustion and explosion. Since hot air cannot flow between spaces, the temperature cannot flow between them either; and since the airflow in adjacent spaces is drawn towards the center, a certain temperature transition zone is formed between adjacent spaces, which can prevent sudden changes in ambient temperature when the film enters or exits the temperature zone.

[0034] Please see Figures 3 to 5The negative pressure air curtain device 5 preferably adopts a static pressure box structure. The first exhaust section 51 and the second exhaust section 52 are both located on the air curtain static pressure box. Air curtain flow equalization plates 53 and / or air regulating plates are provided at both the first exhaust section 51 and the second exhaust section 52. The air curtain flow equalization plates 53 ensure uniform airflow. Without these plates, problems such as higher airflow near the exhaust port (exhaust duct) and insufficient airflow further away from the exhaust port (exhaust duct) will occur. Furthermore, the membrane will not be subjected to strong airflow impact when passing through, further ensuring the ventilation effect within the space. Preferably, the air curtain flow equalization plates 53 inside the first exhaust section 51 and / or the second exhaust section 52 are multi-layered (e.g., two or more layers) to improve the flow equalization effect. The multi-layered air curtain equalization plate 53 is arranged parallel to or inclined along the film conveying direction. For example, in some embodiments, the air curtain equalization plate 53 consists of two layers arranged parallel to (horizontally) along the film conveying direction; in other embodiments, the air curtain equalization plate 53 is not parallel to the film conveying direction but forms an angle with it, i.e., the inclined arrangement. The air curtain equalization plate 53 has air holes, and the air holes in each layer are arranged oppositely or staggeredly; where opposite arrangement means that the air holes are corresponding in the wind speed direction, and the line connecting several corresponding air holes is consistent with the wind speed direction; while staggered arrangement means that the air holes are staggered in the wind speed direction. In some embodiments, the air holes are, for example, small holes, closely arranged on the air curtain equalization plate 53; in other embodiments, the air holes are arranged strip holes, or the air curtain equalization plate 53 is grid-like or mesh-like; or it is a combination of multiple hole types, and the specific design is selected according to the actual situation.

[0035] Furthermore, preferably, channel side plates 55 are provided on both the outer sides of the first exhaust section 51 and the second exhaust section 52. The channel side plates 55, together with the air curtain equalization plates 53 of the first exhaust section 51 and the second exhaust section 52, form the four side walls of the channel space 54. Thus, the position and size of the channel space 54 are no larger than the connection opening between the two spaces, and it is sealed to the connection opening, ensuring that the airflow at the connection opening can only flow to the first exhaust section 51 and the second exhaust section 52, and cannot escape from other places around the connection opening. It is understood that for cases where the temperature zone or other process space is small, or the first exhaust section 51 and the second exhaust section 52 are large, the side walls of the temperature zone or other process space can be equivalent to the side walls of the channel space 54, effectively achieving the desired effect, thus eliminating the need for channel side plates 55 (and other structures restricting the connection opening).

[0036] In some embodiments, a slit baffle 56 is provided on at least one side of the first exhaust section 51 and the second exhaust section 52, adjacent to the channel side plate 55; for example, in the illustrated embodiment, this is a sealing connection between two upper and lower baffles fixed to the outside; the slit baffle 56 forms a slit at the entrance and / or exit of the channel space 54, the size of which is smaller than the channel space 54. The distance between the first exhaust section 51 and the second exhaust section 52 cannot be too close, therefore the slit baffle 56 further defines the size of the entrance and / or exit of the channel space 54, and preferably the position and size of the slit are adjustable (e.g., the slit is limited by two detachable / adjustable baffles). Specifically, for example, the slit is located in a central position between the first exhaust section 51 and the second exhaust section 52, so that the distance between the membrane and the first exhaust section 51 and the second exhaust section 52 is substantially the same.

[0037] In some embodiments, both the first exhaust section 51 and the second exhaust section 52 are strip-shaped to fit the width of the space connection opening; the air curtain equalization plate 53 is a porous strip-shaped flat plate, and the air curtain equalization plates 53 of the first exhaust section 51 and the second exhaust section 52 are parallel. This solution is small in size while achieving the required functions, which is convenient for production and use; the negative pressure air curtain device in the oven should not be too large to ensure the uniformity and efficiency of the main heating equipment (static pressure box). In addition, if the air curtain device is too large, it will affect the overall size of the equipment box, resulting in increased costs, low heating efficiency, and poor heat preservation.

[0038] More specifically, the two air curtain static pressure boxes (first airtight air box 57 and second airtight air box 58) of the negative pressure air curtain device 5 are respectively connected to exhaust pipes (first exhaust pipe 59 and second exhaust pipe 510). The exhaust pipes are preferably located on both sides of the air curtain static pressure box; this method of connecting exhaust pipes on both sides helps to ensure uniform airflow throughout the air curtain equalization plate 53. Preferably, the ends of the exhaust pipes furthest from the air curtain static pressure box are arranged side-by-side, such as sharing a side wall and being fixedly connected together, making the structure more compact, facilitating installation, and reducing the number of air outlets in the oven.

[0039] Please see again Figure 1 , Figure 2 The oven body has exhaust vents 61 located near the side partitions (partitions at both ends of the oven body's length) and / or on the side walls parallel to the partitions (i.e., side walls at both ends of the oven body's length). Optionally, exhaust vents may be located on both sides of each partition. This design places the oven exhaust vents in the dead corners of the oven, i.e., locations where evaporated solvent tends to stagnate and accumulate. This focuses exhaust from these solvent-prone areas, ensuring airflow in the dead corners and improving the efficiency and effectiveness of solvent removal.

[0040] The oven air inlet 62 is related to the setting of the static pressure chamber. For example, an air inlet is provided on the side wall of the chamber perpendicular to the partition (i.e., on both sides of the chamber's length). Specifically, for example, the oven air inlet 62 corresponding to the nozzle-type static pressure chamber 4 is located in the middle of the temperature zone, on both sides of the oven body; the air inlet position corresponding to the parallel air circulation treatment device corresponds to the parallel air duct air inlet 32. For the upper drying duct, the air inlet and exhaust port can also be opened at the top of the oven body; for the lower drying duct, the situation and setting principle of the air inlet and exhaust port can be similar to that of the upper drying duct, the difference being that they are opened on the left and right sides of the oven body. The oven exhaust port 61 is sealed to the chamber body and is connected to a negative pressure fan and exhaust gas treatment system, etc. The relevant required components / systems are existing technology and will not be described in detail here.

[0041] The oven body has two ends, namely an active drum chamber 81 and a passive drum chamber 82, corresponding to the active drum 71 and the passive drum 72, respectively. Accordingly, an active roller temperature zone is provided on one side of the upper drying tunnel 1 and the lower drying tunnel 2, and a passive roller temperature zone is provided on the other side. The active roller temperature zone is located inside the active drum chamber 81 and may be a single temperature zone or may be divided into two or more temperature zones within the active drum chamber 81; similarly, the passive roller temperature zone is located inside the passive drum chamber 82 and may be a single temperature zone or may be divided into two or more temperature zones. Preferably, the passive roller heating zone is equipped with a far-infrared heating device or a ceramic heating device. The film and steel strip are heated in the passive roller heating zone using far-infrared or ceramic heating methods. The passive roller heating zone is located between the upper and lower drying tunnels in the film conveying path. In existing equipment, there is no heating device in the passive drum chamber 82, and the temperature is only maintained by the box structure. After the film passes through this section, the temperature will drop. When it enters the temperature zone of the lower drying tunnel, the film temperature will change abruptly, which will affect the process quality. This solution can achieve more precise temperature control, which can make the film temperature change basically continuously and avoid temperature changes affecting film quality.

[0042] Preferably, explosion vents 63 are provided in the first temperature zone and / or other temperature zones in the upper drying tunnel (such as the second and third temperature zones downstream of the first temperature zone). Explosion vents 63 are preferably located at least in the first temperature zone and the second temperature zone downstream of it, where the solvent concentration is high, allowing for pressure relief in extreme conditions. Explosion vents 63 are, for example, located at the top of the chamber. More preferably, each temperature zone is also equipped with monitoring devices for temperature, air pressure, and other conditions, facilitating timely intervention or explosion relief in extreme situations, thereby protecting equipment and personnel safety.

[0043] In summary, the oven structure of the casting machine of this invention divides different processing zones and adopts different processing methods according to the path of the film movement. When the film slurry just enters the drying tunnel, preheating air is blown through parallel air ducts to harden the surface of the film slurry and ensure airflow, while avoiding hot air blowing directly onto the film surface, which would affect the film quality. Subsequently, hot air is blown directly onto the film surface to ensure the efficiency and effect of heating and solvent evaporation. Furthermore, this solution preferably places the exhaust vent in a specific dead corner to better discharge the solvent and avoid solvent gas accumulation, which could lead to recondensation and dripping onto the film or cause combustion and explosion problems. Furthermore, this solution preferably incorporates a negative pressure air curtain device, in which two oppositely positioned exhaust vents simultaneously draw air, each equipped with an air curtain flow equalization plate to ensure uniform airflow intensity. A negative pressure air curtain is formed in the channel space between the two exhaust vents, allowing the film to be transmitted between the two spaces. Because of the negative pressure air curtain between these two spaces, issues such as temperature and gas interaction (e.g., escape / cross-contamination of gases with different temperatures and compositions) are avoided, effectively ensuring the accuracy and stability of process environment control for high-end processes.

Claims

1. An oven structure for a casting machine, comprising an upper drying tunnel (1) and a lower drying tunnel (2), characterized in that, A first temperature zone is provided in the upper drying tunnel (1), and a parallel air circulation treatment device is provided in the first temperature zone. The parallel air circulation treatment device includes at least one set of parallel air duct inlet (32) and parallel air duct outlet (31) arranged opposite to each other. The parallel air duct inlet (32) and parallel air duct outlet (31) are arranged above and below the steel belt, or are arranged only above the steel belt.

2. The oven structure of the casting machine according to claim 1, characterized in that, The parallel air duct inlet (32) and parallel air duct outlet (31) are provided with flow equalization plates and / or air regulating plates; wherein, the flow equalization plates are provided with a number of air holes or a number of slit holes.

3. The oven structure of the casting machine according to claim 2, characterized in that, The parallel air duct outlet (31) is located near the entrance of the upper drying duct (1), and the parallel air duct inlet (32) is located on the opposite side of the parallel air duct outlet (31).

4. The oven structure of the casting machine according to any one of claims 1 to 3, characterized in that, The upper drying tunnel (1) and the lower drying tunnel (2) contain several temperature zones using a longitudinal air circulation treatment device, each of which is an adjustable temperature zone.

5. The oven structure of the casting machine according to claim 4, characterized in that, An active roller temperature zone is provided on one side of the upper drying tunnel (1) and the lower drying tunnel (2), and a passive roller temperature zone is provided on the other side. The passive roller temperature zone is equipped with a far-infrared heating device or a ceramic heating device.

6. The oven structure of the casting machine according to claim 5, characterized in that, Partitions are provided at the adjacent locations of the two temperature zones and at the entrances and exits of the upper drying tunnel (1) and the lower drying tunnel (2). The partitions have a connecting opening in the middle, and a negative pressure air curtain device (5) is provided at the connecting opening. The negative pressure air curtain device (5) includes a first exhaust section (51) and a second exhaust section (52) arranged opposite to each other. A channel space (54) for the steel belt to pass through is formed between the first exhaust section (51) and the second exhaust section (52). The width of the channel space (54) is adapted to the width of the film.

7. The oven structure of the casting machine according to claim 6, characterized in that, The first exhaust section (51) and the second exhaust section (52) are both located on the air curtain static pressure box. An air curtain flow equalization plate (53) and / or an air regulating plate are provided at both the first exhaust section (51) and the second exhaust section (52).

8. The oven structure of the casting machine according to any one of claims 1 to 3, characterized in that, The oven body has an exhaust vent (61) near the side partitions and / or parallel to the partitions on the side walls.

9. The oven structure of the casting machine according to claim 8, characterized in that, An air inlet is provided on the side wall of the box perpendicular to the partition.

10. The oven structure of the casting machine according to claim 4, characterized in that, Explosion vents (63) are provided in the first temperature zone and / or other temperature zones of the upper drying tunnel (1).

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