A casting production line for fuel cell carbon paper preparation

Abstract

This invention provides a casting production line for preparing carbon paper for fuel cells. This production line uses a casting process to replace the traditional papermaking process for preparing carbon paper. Compared to papermaking, this casting production line has simpler equipment, lower investment, simpler operation, lower personnel skill requirements, and can achieve large-scale continuous production. The casting production line for preparing carbon paper for fuel cells includes a feeding device, an overflow trough, a material belt, a filtration device, and a baking device. The feeding device is connected to the overflow trough to inject slurry into the overflow trough. The overflow trough has an overflow port, which is located on the same plane as the upper surface of the material belt. The material belt has mesh openings. The filtration device directly or indirectly abuts against the lower surface of the material belt. The baking device is used to bake the wet fibers on the material belt. In the conveying direction of the material belt, the baking device is located downstream of the filtration device.

Description

Technical Field

[0001] This utility model relates to the field of carbon paper preparation technology, specifically to a casting production line for preparing carbon paper for fuel cells. Background Technology

[0002] With the increasing global demand for clean energy, hydrogen fuel cells, as a highly efficient and environmentally friendly energy conversion device, are receiving increasing attention. Currently, carbon paper preparation methods are mainly divided into two categories: dry preparation and wet preparation. Among them, the wet preparation process is widely used in the production of high-quality carbon paper because it can better control the uniformity of carbon fiber dispersion and the microstructure of the paper. The basic process of wet preparation involves soaking and uniformly dispersing short-cut carbon fibers in a specific solution, followed by using a papermaking process to convert the carbon fiber slurry into carbon paper with a certain mechanical strength and porous structure. The advantage of this technology lies in its high technological maturity; by precisely controlling the slurry composition and papermaking parameters, it is possible to produce carbon paper products with a dense structure and stable performance, meeting the high-performance requirements of hydrogen fuel cells for gas diffusion layer materials.

[0003] However, the wet preparation process is relatively complex, involving multiple delicate operation steps, which requires a high level of technical skills and experience from the operators. Professional training is needed to improve the quality of personnel. At the same time, the equipment required for wet preparation includes high-precision dispersion, stirring, paper making and other steps, which requires a large investment in equipment and increases the initial operating costs of enterprises. Utility Model Content

[0004] The purpose of this invention is to provide a casting production line for preparing carbon paper for fuel cells. This production line uses a casting process to replace the traditional papermaking process for preparing carbon paper. Compared with the papermaking process, the casting production line has simpler equipment, lower investment, simpler operation, lower requirements for personnel skills, and can achieve large-scale continuous production operations.

[0005] To achieve the above objectives, this utility model provides a casting production line for preparing carbon paper for fuel cells. The casting production line includes a feeding device, an overflow trough, a material belt, a filtration device, and a baking device. The feeding device is connected to the overflow trough to inject slurry into the overflow trough. The overflow trough has an overflow port, which is located on the same plane as the upper surface of the material belt. The material belt has mesh holes. The filtration device directly or indirectly abuts against the lower surface of the material belt. The baking device is used to bake the slurry located on the material belt. In the transport direction of the material belt, the baking device is located downstream of the filtration device.

[0006] By using the casting production line of this application to prepare carbon paper for fuel cells, compared with the traditional wet carbon paper preparation process, the casting production line has simple equipment, low investment, simple operation, low personnel skill requirements, and can realize large-scale continuous production operations.

[0007] Optionally, it also includes a squeegee plate located on the upper side of the strip and having a predetermined gap between it and the upper surface of the strip in the vertical direction.

[0008] Optionally, in the conveying direction of the conveyor belt, the squeegee is disposed on the downstream side of the overflow trough and on the upstream side of the filtration device.

[0009] Optionally, a sealing plate is also provided on the outside of the overflow trough. The upper surface of the sealing plate is located on the same plane as the overflow port. The sealing plate extends to the material strip, and the lower surface of the sealing plate presses against the material strip vertically.

[0010] Optionally, the filtration device includes a filtration box, which is connected to a first negative pressure device. A support mesh plate is provided on the upper surface of the filtration box, and the support mesh plate is in contact with the lower surface of the material belt.

[0011] Optionally, the filtration box has a right-angled trapezoidal cross-section in the vertical direction, with a long side wall, a short side wall, and a straight side wall and a hypotenuse connecting the long side wall and the short side wall; a drain port is provided at the intersection of the long side wall and the hypotenuse, and the drain port can be connected to or disconnected from the waste liquid recovery pipeline.

[0012] Optionally, a first air outlet is provided on the short sidewall, and the first air outlet is connected to the air inlet side of the first negative pressure device; the air outlet side of the first negative pressure device is also connected to a condensation recovery device.

[0013] Optionally, the baking apparatus includes a box-shaped or tubular oven extending in the same direction as the conveyor belt. The oven is located downstream of the filtration device and covers the conveyor belt located above it. Air inlets, designated as a first air inlet and a second air inlet, are located at the front and rear ends of the oven in the conveying direction, respectively. An exhaust port is located at the top of the oven. The exhaust port is connected to the air inlet side of a second negative pressure device, and the air outlet side of the second negative pressure device is connected to a condensation recovery device.

[0014] Optionally, the oven is provided with a first heating element and a second heating element, with the first heating element located on the upper side of the conveyor belt and the second heating element located on the lower side of the conveyor belt.

[0015] Optionally, it also includes a feeding cylinder, the bottom of which has an outlet connected to the inlet of the overflow tank, and a first pump is connected between the inlet and the outlet; the top of the feeding cylinder also has a return outlet connected to the outlet of the overflow tank, and a second pump is connected between the return outlet and the outlet.

[0016] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0018] Figure 1 This is a schematic diagram of the casting production line used for preparing carbon paper for fuel cells in an embodiment of this utility model.

[0019] Figure label:

[0020] 1-Feeding cylinder; 2-Agitator; 3-Second liquid level sensor; 4-Slurry supply pipeline; 5-First valve; 6-Raw material inlet (feeding cylinder); 7-Return port; 8-Overflow trough; 9-Discharge port; 10-Inlet; 11-Second pump; 12-Second valve; 13-First roller; 14-First liquid level sensor; 15-Smoothing plate; 16-Support mesh plate; 17-First negative pressure device; 18.1-First air inlet; 18.2-Second air inlet; 19-Drain port;

[0021] 20-Filter box; 21-First air outlet; 22-Condensation recovery device; 23-Second negative pressure device; 24-Exhaust port; 25-Oven; 26.1-First heating element; 26.2-Second heating element; 27-Thickness gauge; 28-First correction device; 29-Tension testing device;

[0022] 30.1-First idler roller; 30.2-Second idler roller; 31-Rewinding shaft; 32-Second roller; 33-Material belt; 34-Cleaning device; 35-Second correction device; 36-Third pump; 37-First pump; 38-Third valve; 39-Liquid outlet; 40-Waste liquid recovery pipeline. Detailed Implementation

[0023] This invention provides a casting production line for preparing carbon paper for fuel cells. This production line uses casting technology to replace the traditional papermaking process for preparing carbon paper. Compared with the papermaking process, the casting production line has simpler equipment, lower investment, simpler operation, lower personnel skill requirements, and can achieve large-scale continuous production operations.

[0024] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0026] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the casting production line used for preparing carbon paper for fuel cells in an embodiment of this utility model.

[0027] like Figure 1 As shown, this utility model provides a casting production line for preparing carbon paper for fuel cells. The casting production line includes a feeding device, an overflow trough 8, a material belt 33, a filtration device, and a baking device. The feeding device is responsible for stably supplying carbon fiber slurry (hereinafter referred to as slurry) to the casting production line. The feeding device is connected to the overflow trough 8 to inject the slurry into the overflow trough 8. The overflow trough 8 has an overflow port, and the overflow port is located on the same plane as the upper surface of the material belt 33. The material belt 33 has mesh. The filtration device directly or indirectly abuts against the lower surface of the material belt 33. The baking device is used to bake the slurry located on the material belt 33. In the slurry transport direction, the baking device is located downstream of the filtration device.

[0028] In a specific example, the conveyor belt 33 is a closed-loop conveyor belt. Specifically, the conveyor belt 33 is wound around two rollers, namely the first roller 13 and the second roller 32. The casting production line includes a loading side and a unloading side. In the conveying direction, the loading side is located on the left side (loading side), and the unloading side is located on the right side (unloading side). The upper conveyor belt 33 is used to convey the slurry. The upper conveyor belt 33 refers to the portion located above the two rollers during the process of the conveyor belt 33 rotating around them. In this embodiment, the upper conveyor belt 33 extends horizontally. The overflow port is on the same plane as the upper surface of the upper conveyor belt 33 and is in contact with it.

[0029] In this embodiment, the material strip 33 is a key component in the casting process, and has the characteristics of high temperature resistance (not less than 200°C), tensile strength (tensile strength not less than 600 N / cm), smooth and non-sticky surface, microporous air permeability (pore size 20-100 mesh), and material of PET or PTFE.

[0030] As an optional example, a soft seal is provided between the overflow port and the conveyor belt 33 to prevent slurry from flowing back through the gap between the overflow trough 8 and the conveyor belt 33. Specifically, a sealing plate with a certain slope is also provided on the outside of the overflow trough 8. The upper surface of the sealing plate is on the same plane as the overflow port, the sealing plate extends to the conveyor belt 33, and the lower surface of the sealing plate presses vertically against the conveyor belt 33. The sealing plate is made of a flexible material, such as rubber or silicone.

[0031] By using a sealing plate, the slurry can be better guided to the material belt 33, while also preventing the slurry in the material belt 33 from flowing back into the overflow tank 8.

[0032] In this embodiment, the casting production line for preparing fuel cell carbon paper also includes a smoothing plate 15, which is located above the material belt 33 and has a predetermined gap in the vertical direction with the upper surface of the material belt 33. The smoothing plate 15 is used to smooth the upper surface of the slurry flow to improve the surface smoothness of the finished paper. The gap between the smoothing plate 15 and the overflow trough 8 is adjustable. By setting the smoothing plate 15, the slurry can be smoothed, and the thickness of the slurry layer on the material belt 33 can also be kept within a predetermined range by the predetermined gap. In the slurry transport direction, the smoothing plate 15 is located downstream of the overflow trough 8 and upstream of the filtration device. That is, after the slurry overflows to the material belt 33, it is first smoothed by the smoothing plate 15, and then the slurry layer is filtered by the filtration device.

[0033] Meanwhile, a first liquid level sensor 14 is also provided on the upstream side of the slurry plate 15. The first liquid level sensor 14 is used to limit the limit value of the slurry height on the material belt 33. After the slurry height on the material belt 33 reaches the limit value, the first liquid level sensor 14 sends a signal. The pumping rate of the first pump 37 can be adjusted according to this signal, and the rotation speed of the material belt 33 can also be adjusted according to this signal. Those skilled in the art can set these settings themselves.

[0034] An overflow trough 8, equipped with an overflow port, is connected to a feeding device. The feeding device includes a feeding cylinder 1, the bottom of which has an outlet 39 connected to the inlet 10 of the overflow trough 8. A first pump 37 connects the inlet 10 and the outlet 39. Activating the first pump 37 pumps slurry from the feeding cylinder 1 into the overflow trough 8. The overflow trough 8 has an overflow port, the lowest point of which is on the same plane as the material belt 33. Therefore, when the height of the slurry in the overflow trough 8 is higher than the lowest point of the overflow port, it overflows into the material belt 33. The specific structure of the overflow trough 8 can be selected by those skilled in the art as needed.

[0035] In a specific example, the first pump 37 forms negative feedback with the first liquid level sensor 14. That is, when the slurry level in the overflow tank 8 is detected to be high, the speed of the first pump 37 slows down, the slurry supply decreases, and the liquid level drops until the set value is reached. Then the speed of the first pump 37 tends to stabilize, and the slurry supply tends to stabilize, thus achieving a stable casting of the set thickness. The reverse is also true.

[0036] As an optional approach, the top of the feeding cylinder 1 is also provided with a return port 7 that communicates with the discharge port 9 of the overflow tank 8, and a second pump 11 is connected between the return port 7 and the discharge port 9. In this way, excess slurry can be recovered and reused. In the above scheme, a second liquid level sensor 3 is also provided on the top of the feeding cylinder 1 to detect the liquid level of the carbon paper material in the feeding cylinder 1.

[0037] In the specific operation process, the first pump 37 is started to pump the set amount of carbon paper into the overflow tank 8. After the corresponding slurry has completed the casting process, the first pump 37 is turned off and the second pump 11 is turned on to recover the remaining slurry in the overflow tank 8 to prevent it from settling over time. The feeding cylinder 1 is also equipped with a stirring device 2, which is used to stir the slurry in the feeding cylinder 1 in real time, so as to play the role of stirring while casting and prevent the slurry from stratifying unevenly.

[0038] In the aforementioned scheme, the first pump 37 and the second pump 11 can be variable frequency speed-regulating screw pumps, which can change the slurry delivery flow rate in real time by adjusting the rotation speed. Other types of pumps can also be used, and those skilled in the art can choose according to their needs.

[0039] In the aforementioned technical solution, the feeding cylinder 1 is also connected to a slurry supply pipe 4, which is connected to the raw material inlet 6 of the feeding cylinder 1. The slurry supply pipe 4 is also equipped with a first valve 5 to regulate its connection and disconnection. Furthermore, a second valve 12 is installed between the outlet 9 and the second pump 11, and a third valve 38 is installed between the liquid outlet 39 and the first pump 37. The second liquid level sensor 3, the first valve 5, and the slurry delivery pump of the pulping production line are interlocked to ensure stable material supply.

[0040] In some other specific embodiments, one of the first roller 13 and the second roller 32 is connected to a power source to serve as a drive roller, while the other serves as a redirecting roller. The power source can be a servo motor, thereby allowing for adjustable and controllable rotational speed of the drive roller.

[0041] A first idler roller 30.1 and a take-up shaft 31 are also provided on the rear side of the second roller 32. In the example shown, the take-up shaft 31 is also provided on the side of the second roller 32 away from the first roller 13; the first idler roller 30.1 is also provided between the take-up shaft 31 and the second roller 32. The first idler roller 30.1 supports and guides the formed carbon paper, preventing the carbon paper from breaking or bending. The take-up shaft 31 is located at the end of the production line and is used to take up the carbon fiber base paper separated from the drying strip 33. The take-up shaft 31 is driven by a servo motor and torque controlled. The first idler roller 30.1 is located between the second roller 32 and the take-up shaft 31.

[0042] A first correction device 28, a tension detection device 29, and a thickness gauge 27 are also provided between the first idler roller 30.1 and the second roller 32. The first correction device 28 can straighten the carbon paper in its width direction, the tension detection device 29 can determine the tension on the carbon paper, and the thickness gauge 27 can measure and evaluate the thickness of the carbon paper.

[0043] The tension detection device 29 and the servo motor of the take-up shaft 31 form a torque closed-loop control. When the paper winding tension is detected to exceed the set range, the servo motor of the take-up shaft 31 automatically decelerates to reduce the winding tension to the set range, preventing the paper from breaking due to excessive tension. When the paper winding tension is detected to be below the set range, the servo motor of the take-up shaft 31 automatically accelerates to restore the winding tension to the set range, preventing uneven winding of the paper. The first deviation correction device 28 is used to solve the problem of the material belt 33 running off-track during operation.

[0044] As a more specific example, the lower strip 33 is also provided with several spaced second idlers 30.2. A cleaning device 34 and a second deviation correction device 35 can also be provided on the lower strip 33. The cleaning device 34 cleans the strip 33 of contaminants in real time to ensure the quality of the casting process.

[0045] The specific structure of the filtration device in this application is described below. The working principle of the filtration device is to achieve solid-liquid separation of carbon fiber slurry through low-pressure adsorption. That is, the carbon fiber mesh is uniformly dispersed above the material belt 33, enters the baking device to dry into paper, and the slurry solvent passes through the material belt 33 and is recovered and drawn away for the preparation of the next batch of slurry.

[0046] In an embodiment of this application, the filtration device includes a filtration box 20, which is connected to a first negative pressure device 17. The filtration box 20 has a right-angled trapezoidal cross-section in the vertical direction, with a long side wall, a short side wall, and a straight side wall and an inclined side wall connecting the long and short side walls. The long side wall is located near the overflow trough 8, and the short side wall is further away from the overflow trough 8 than the long side wall. A drain port 19 is provided at the intersection of the long side wall and the inclined side wall, and the drain port 19 can be connected to or disconnected from the waste liquid recovery pipe 40. Specifically, the waste liquid recovery tank is also equipped with a third pump 36 to pump out the slurry from the filtration box 20.

[0047] This allows the filtered slurry to be guided and collected at the bottom of the filtration box 20, facilitating smooth drainage from the filtration box 20.

[0048] In the example shown in the figure, the short sidewall is closer to the baking device than the long sidewall. A first air outlet 21 is provided on the short sidewall, and the first air outlet 21 is connected to the air inlet side of the first negative pressure device 17. The air outlet side of the first negative pressure device 17 is also connected to a condensation recovery device 22.

[0049] In the above embodiment, the first negative pressure device 17 is an exhaust fan with controllable airflow to achieve low air pressure inside the filtration box 20. A liquid outlet 39 is provided at the bottom of the filtration box 20, and the outlet 39 is sequentially connected to the third pump 36 and the waste liquid recovery pipe 40. The cross-section of the filtration box 20 is a right-angled trapezoid to achieve gas-liquid separation between the waste liquid and the low-pressure air.

[0050] Therefore, by placing the first air outlet 21 on the short side wall, the slurry can be filtered better, and the extracted slurry can be prevented from entering the first air outlet 21.

[0051] In the example shown, a support mesh plate 16 is provided on the side with the straight side wall (i.e., the upper end face of the filtration box 20). The support mesh plate 16 is made of stainless steel, with 1mm diameter holes arranged in a staggered pattern longitudinally, and has a smooth and flat surface. The upper surface of the support mesh plate 16 is in contact with the lower surface of the material belt 33. The support mesh plate 16 is in close contact with the lower surface of the material belt 33. By providing the support mesh plate 16, the material belt 33 is supported, preventing deformation of the material belt 33 during the filtration process. In the technical solution of this application, the material belt 33 located on the upper side extends horizontally, and both the squeegee 15 and the support mesh plate 16 extend horizontally.

[0052] The specific structure of the baking apparatus in this application will be described below.

[0053] The baking apparatus includes a box-shaped or tubular oven 25, which extends in the same direction as the conveyor belt 33. The oven 25 is located downstream of the filtration device and covers the conveyor belt 33 located above it. Air inlets are provided at the front and rear ends of the oven 25 in the conveying direction, namely a first air inlet 18.1 and a second air inlet 18.2, respectively. An exhaust port 24 is provided at the top of the oven 25. The exhaust port 24 is connected to the air inlet side of a second negative pressure device 23, and the air outlet side of the second negative pressure device 23 is connected to a condensation recovery device 22. The second negative pressure device 23 is an exhaust fan with controllable airflow, capable of promptly removing the water and alcohol vapors generated during the baking process. The condensation recovery device 22 is used to recover the water and alcohol vapors.

[0054] A first heating element 26.1 and a second heating element 26.2 are installed inside the drying oven 25. The first heating element 26.1 is located on the upper side of the conveyor belt 33, and the second heating element 26.2 is located on the lower side of the conveyor belt 33. The first heating element 26.1 can be an infrared lamp tube directly or indirectly fixedly connected inside the drying oven 25, and the second heating element 26.2 is a heating plate that can be attached to the lower surface of the conveyor belt 33. The heating plate can be a cast aluminum heating plate. This not only supports the conveyor belt 33 but also improves the heating efficiency of the slurry on the upper part of the conveyor belt 33.

[0055] In the example shown, the first heating elements 26.1 are spaced apart along the conveying direction, and when the second heating element 26.2 is a heating plate, several heating plates are connected sequentially along the conveying direction. The temperature of each heating element is independently controllable. By adjusting the temperature of each group of heating elements through gradient adjustment, the carbon fiber mesh is dried into paper quickly and efficiently.

[0056] In this embodiment, one end of the oven 25 extends to the side where the second roller 32 is located, and the other end extends to the side where the filtration device is located, thereby increasing the baking length of the slurry.

[0057] The following is a detailed description of the operation process of the casting production line for preparing carbon paper for fuel cells:

[0058] First, preheat the oven 25 to the required temperature.

[0059] Second, set the pulp supply and the running speed of the conveyor belt 33 according to the target thickness of the paper.

[0060] Third, start the casting production line and begin casting production. This step should be linked with the pulping production line to ensure a stable supply of carbon fiber pulp and to ensure that waste liquid generated during casting is removed in a timely manner.

[0061] Fourth, after production ends, shut down the casting production line.

[0062] By using the casting production line of this application to prepare carbon paper for fuel cells, compared with the traditional papermaking process, the casting production line has simple equipment, low investment, simple operation, low personnel skill requirements, and can realize large-scale continuous production operations.

[0063] Specifically, this technical solution uses processes such as feeding, casting, filtration, drying, separation, and winding to produce carbon fiber base paper, and the process is simple.

[0064] In addition, it can precisely control the amount of material supplied, thereby achieving precise control over the thickness of the finished paper.

[0065] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A casting production line for preparing carbon paper for fuel cells, characterized in that, It includes a feeding device, an overflow trough (8), a mesh belt (33), a filtration device, and a baking device; The feeding device is connected to the overflow trough (8) to inject slurry into the overflow trough (8). The overflow trough (8) has an overflow port. The lowest position of the overflow port is on the same plane as the upper surface of the material belt (33). The filtration device directly or indirectly abuts against the lower surface of the material belt (33). The baking device is used to bake the slurry located on the material belt (33). In the direction of slurry transport, the baking device is located downstream of the filtration device.

2. The casting production line for preparing fuel cell carbon paper according to claim 1, characterized in that, It also includes a smearing plate (15), which is located on the upper side of the strip (33) and has a set gap with the upper surface of the strip (33) in the vertical direction.

3. The casting production line for preparing fuel cell carbon paper according to claim 2, characterized in that, In the direction of slurry transport, the slurry plate (15) is positioned between the overflow trough (8) and the filtration device.

4. The casting production line for preparing fuel cell carbon paper according to claim 1, characterized in that, The overflow trough (8) is also provided with a sealing plate. The upper surface of the sealing plate is on the same plane as the overflow port, and the lower surface of the sealing plate is pressed against the material strip (33) vertically.

5. The casting production line for preparing fuel cell carbon paper according to claim 1, characterized in that, The filtration device includes a filtration box (20), which is connected to a first negative pressure device (17). A support mesh plate (16) is provided on the upper surface of the filtration box (20), and the support mesh plate (16) is in contact with the lower surface of the material belt (33).

6. The casting production line for preparing fuel cell carbon paper according to claim 5, characterized in that, The filtration box (20) has a right trapezoidal cross section in the vertical direction, and has a long side wall, a short side wall, and a straight side wall and a hypotenuse connected to the long side wall and the short side wall. A drain port (19) is provided at the intersection of the long side wall and the hypotenuse, and the drain port (19) can be connected to or disconnected from the waste liquid recovery pipe (40).

7. The casting production line for preparing fuel cell carbon paper according to claim 6, characterized in that, A first air outlet (21) is provided on the short side wall, and the first air outlet (21) is connected to the air inlet side of the first negative pressure device (17); the air outlet side of the first negative pressure device (17) is connected to a condensation recovery device (22).

8. The casting production line for preparing fuel cell carbon paper according to any one of claims 1-7, characterized in that, The baking device includes an oven (25) that extends in the same direction as the conveyor belt (33). The oven (25) is located downstream of the filtration device, and part of the conveyor belt (33) passes through the oven (25). In the transmission direction, the oven (25) is provided with a first air inlet (18.1) and a second air inlet (18.2). An exhaust port (24) is provided at the top of the oven (25). The exhaust port (24) is connected to the air inlet side of the second negative pressure device (23), and the air outlet side of the second negative pressure device (23) is connected to the condensation recovery device (22).

9. The casting production line for preparing fuel cell carbon paper according to claim 8, characterized in that, The oven (25) is provided with a first heating element (26.1) and a second heating element (26.2). The first heating element (26.1) is located on the upper side of the material belt (33), and the second heating element (26.2) is located on the lower side of the material belt (33).

10. The casting production line for preparing fuel cell carbon paper according to any one of claims 1-7, characterized in that, It also includes a feeding cylinder (1), the bottom of which is provided with an outlet (39) connected to the inlet (10) of the overflow tank (8), and a first pump (37) is connected between the inlet (10) and the outlet (39); the top of the feeding cylinder (1) is also provided with a return port (7) connected to the outlet (9) of the overflow tank (8), and a second pump (11) is connected between the return port (7) and the outlet (9).

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