A dripping device and process for dripping wet film of high-calcium tofu skin of kale

Abstract

The present application belongs to the technical field of draining, and discloses a draining device for kale high-calcium dried beancurd sheet wet film, which comprises a conveying belt for transporting dried beancurd sheet wet film, a working cavity is arranged below the conveying belt along the conveying direction of the conveying belt, and the working surface of the working cavity faces the lower surface of the conveying belt; when the working cavity is in a negative pressure state, the dried beancurd sheet wet film is subjected to a downward suction force through the holes of the flexible mesh belt, so as to accelerate the migration and removal of internal moisture of the dried beancurd sheet wet film; when the working cavity is in a positive pressure state, gas is sprayed upward through the holes, and a transient micro air gap is formed between the dried beancurd sheet wet film and the flexible mesh belt, so as to release liquid bridge adsorption and avoid structural damage of the wet film due to continuous adhesion; through periodic switching of the negative pressure and the positive pressure, water migration and removal are realized in the negative pressure stage, and gas is actively injected in the positive pressure stage to form a transient micro air gap, so as to cut off the liquid bridge adsorption force and make the wet film temporarily separate from the supporting surface.

Description

Technical Field

[0001] This invention belongs to the field of drainage technology, specifically relating to a drainage device and drainage process for a wet film of kale and high-calcium bean curd sticks. Background Technology

[0002] As a traditional soy protein product, dried bean curd sticks have been gradually developing towards functional and nutritionally fortified directions in recent years, driven by the trend of health foods. For example, kale is compounded with soluble calcium sources (such as calcium lactate and calcium glycine) and added to the dried bean curd stick base to produce "high-calcium kale dried bean curd sticks," meeting consumers' demand for high-protein, high-calcium, plant-based functional foods. Because the moisture content of dried bean curd stick wet film is usually as high as 70%–80%, and its texture is soft and gel-like, it is necessary to reduce the moisture content to about 50% through a draining device to ensure the smooth progress of subsequent cutting and drying processes. However, in actual production, it has been found that due to the special composition and structure of high-calcium kale dried bean curd stick wet film, traditional draining methods, especially negative pressure suction draining, have significant drawbacks: Modern tofu skin production lines generally employ a continuous moving conveyor system, where the wet film moves at a constant speed through a fixed negative pressure chamber along a flexible mesh belt. During this dynamic process, the continuously applied negative pressure keeps the wet film in an adsorbed state throughout, tightly adhering to the porous support plate or mesh belt surface. If the wet film encounters mesh belt seams, uneven tension, or even slight fluctuations in operating speed, localized areas of the wet film are prone to uneven stretching or high-frequency vibration, leading to edge curling, microporous tearing, or even complete breakage.

[0003] Even with an intermittent (pulsed) negative pressure strategy, attempting to alleviate the adsorption problem by periodically shutting off the negative pressure, the wet membrane still struggles to detach quickly from the support surface during the brief window of negative pressure closure. The fundamental reasons are twofold: firstly, the wet membrane itself has an extremely high water content and high surface tension; secondly, the thin layer of water remaining between the membrane and the support surface forms a stable "liquid bridge," generating significant capillary adsorption force. This adsorption force far exceeds the structural strength of the wet membrane itself, preventing effective desorption within milliseconds.

[0004] As a result, the wet film repeatedly experienced cyclical stress of "adsorption-dragging-partial release" during its movement, which not only failed to alleviate the damage but also accelerated the propagation of microcracks. Under the dual effects of kale fiber disrupting the protein network and uneven calcium distribution causing local embrittlement, the wet film was extremely sensitive to dynamic stress and eventually broke due to fatigue, seriously affecting the yield and production line stability. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a draining device and draining process for a wet film of kale and high-calcium bean curd sticks, so as to solve the problems existing in the above-mentioned background art.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is a draining device for a high-calcium kale and bean curd wet film, including a conveyor belt for transporting the bean curd wet film. The conveyor belt is a porous flexible mesh belt, which allows the bean curd wet film to drain water through the holes during the transport process. A working chamber is provided below the conveyor belt along its own transport direction, and the execution surface of the working chamber faces the lower surface of the conveyor belt. When the working chamber is under negative pressure, a downward suction force is applied to the bean curd wet film through the holes of the flexible mesh belt, which accelerates the migration and removal of internal water in the bean curd wet film. When the working chamber is under positive pressure, gas is ejected upward through the holes, forming an instantaneous micro-air gap between the bean curd wet film and the flexible mesh belt, so as to release liquid bridge adsorption and avoid structural damage to the wet film due to continuous adhesion.

[0007] Preferably, the working chamber is equipped with a control component, which includes a negative pressure interface and a positive pressure interface communicating with the interior of the working chamber. The negative pressure interface is connected to a negative pressure generator to establish a negative pressure environment in the working chamber, so as to draw out the moisture in the tofu skin wet film through the holes of the flexible mesh belt. The positive pressure interface is connected to a positive pressure generator to introduce gas into the working chamber, so as to temporarily detach the tofu skin wet film from the surface of the flexible mesh belt, thereby eliminating liquid bridge adsorption and relieving the structural stress caused by continuous adhesion.

[0008] Furthermore, in one deployment scheme for the negative pressure and positive pressure interfaces: the negative pressure and positive pressure interfaces are independently located at both ends of the working cavity; the bottom surface of the working cavity is an inclined surface, with the negative pressure interface located at the lower end of the inclined surface and the positive pressure interface located at the upper end of the inclined surface.

[0009] Furthermore, in the second deployment scheme for the negative pressure interface and the positive pressure interface, the negative pressure interface and the positive pressure interface are both located at the same end of the working chamber; through the alternating connection between the negative pressure generator and the positive pressure generator and the working chamber, the working chamber is periodically switched between negative pressure state and positive pressure state.

[0010] Furthermore, the working cavity includes a fixed cavity and a rotating joint, the rotating joint being rotatably mounted on the fixed cavity; the contact area between the fixed cavity and the rotating joint is provided with a docking window, and the negative pressure interface and the positive pressure interface are provided on the rotating joint; when the rotating joint rotates, the docking window alternately connects with the negative pressure interface or the positive pressure interface in sequence, so that the working cavity periodically switches to a negative pressure state or a positive pressure state.

[0011] Furthermore, the contact area between the rotary joint and the fixed cavity is divided into a negative pressure area and a positive pressure area along the circumference; the negative pressure interface is distributed in an arc shape on the negative pressure area, and the positive pressure interface is disposed on the positive pressure area; when the rotary joint rotates, the negative pressure area gradually connects with the docking window, so that the negative pressure state in the working cavity increases with the increase of the overlapping area.

[0012] Furthermore, the bottom surface of the working cavity has at least one slope, which is inclined along the direction of the rotary joint to guide condensate or residual moisture to collect and discharge into a predetermined area.

[0013] To solve the above-mentioned technical problems, the second technical solution of the present invention is a drainage process for a wet film of high-calcium kale and dried bean curd, which applies the drainage device described in the deployment scheme one of the internal negative pressure interface and positive pressure interface in the first technical solution. The drainage process includes the following steps: Step S1: Place the wet film of dried bean curd sticks to be drained on the flexible mesh belt and convey it through the working cavity at a uniform speed with the flexible mesh belt; Step S2: Alternately activate the negative pressure generator and the positive pressure generator: When the negative pressure generator is activated, the negative pressure interface located at the lower end of the inclined surface draws water into the working chamber, causing moisture to be discharged downwards through the holes of the flexible mesh belt and flow along the inclined bottom surface of the working chamber to be concentrated and discharged at the lower end; when the positive pressure generator is activated, the positive pressure interface located at the upper end of the inclined surface introduces gas into the working chamber, and the gas is sprayed upwards through the holes of the flexible mesh belt, forming a momentary micro-air gap between the tofu skin wet film and the flexible mesh belt to relieve liquid bridge adsorption; through the periodic synergistic effect of negative pressure dehydration and positive pressure desorption, the moisture content of the tofu skin wet film is reduced.

[0014] To solve the above-mentioned technical problems, the third technical solution of the present invention is a drainage process for a wet film of high-calcium kale and dried bean curd, which applies the drainage device described in the second deployment scheme of the internal negative pressure interface and positive pressure interface of the first technical solution, characterized in that... Step S1: Place the wet film of dried bean curd sticks to be drained on the flexible mesh belt and convey it through the working cavity at a uniform speed with the flexible mesh belt; Step S2: Drive the rotary joint to rotate at a constant angular velocity, so that the negative pressure area on the rotary joint gradually connects with the docking window of the fixed cavity. The negative pressure in the working cavity gradually increases with the increase of the connection area, so as to achieve the gentle suction of the wet film. When the rotary joint continues to rotate until the positive pressure area connects with the docking window, the positive pressure gas is injected instantaneously, so that the wet film is briefly separated from the surface of the mesh belt. Through the continuous rotation of the rotary joint, the working cavity periodically experiences the switching between the gradual increase of negative pressure and the positive pressure pulse, so as to complete the reduction of the moisture content of the wet film.

[0015] The main technical effects of this invention are reflected in the following aspects: Traditional dehydration relies on a single negative pressure, which, while effective in dehydration, is prone to damage to the wet film structure due to continuous adsorption. This invention addresses this by periodically switching between negative and positive pressure. During the negative pressure phase, moisture migrates and is discharged; during the positive pressure phase, gas is actively injected to create instantaneous micro-gaps, breaking the liquid bridge adsorption force and causing the wet film to briefly detach from the support surface. This dynamic balance mechanism of "adsorption and desorption" ensures dehydration efficiency while avoiding the accumulation of tensile stress and the propagation of microcracks caused by continuous adhesion, thus solving the industry problem of highly sensitive functional tofu skin wet films breaking upon detachment during continuous production.

[0016] The bottom surface of the working chamber is designed as an inclined surface, with the negative pressure interface at the lower end and the positive pressure interface at the higher end, forming a "high inlet, low outlet" fluid guidance layout. Condensate and residual liquid generated by negative pressure suction can flow naturally along the slope to the lower end for centralized discharge, avoiding liquid accumulation. Simultaneously, positive pressure gas is injected from the higher end, penetrating the wet film upwards, which is beneficial for the uniform formation of the air cushion. This not only improves drainage efficiency but also prevents water accumulation from affecting the gas path seal or contaminating the back of the product, enhancing the long-term operational stability of the system.

[0017] By arranging the negative pressure interfaces in an arc shape within the negative pressure area of ​​the rotary joint, the connection area between the docking window and the negative pressure area continuously increases with the rotation angle. The negative pressure within the working chamber then rises smoothly, rather than abruptly. This slow-start mechanism effectively suppresses the "pressure shock" experienced during the initial startup of traditional negative pressure systems, preventing localized deformation of the wet film due to sudden suction or accelerated erosion by internal water flow. It is particularly suitable for nutrient-fortified tofu skin wet films with fragile protein networks and poor shock resistance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 A schematic diagram showing the structure with different ends of the negative pressure interface and positive pressure interface for the working chamber; Figure 3 A schematic diagram of a structure in which the working chamber uses both negative pressure and positive pressure interfaces on the same end; Figure 4 for Figure 2 Schematic diagram of the rotating joint; In the diagram: 1. Conveyor belt; 2. Working chamber; 21. Fixed chamber; 22. Rotary joint; 23. Docking window; 24. Negative pressure area; 25. Positive pressure area; 26. Slope; 27. Inclined surface; 3. Negative pressure interface; 4. Positive pressure interface. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, so as to make the technical solution of the present invention easier to understand and master. In the embodiments, it should be understood that the terms "middle," "upper," "lower," "top," "right side," "left end," "above," "back," "center," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, unless otherwise specified in this specific embodiment, the connection or fixing method between components can be achieved by bolt fixing, pin fixing, or pin connection commonly used in the prior art, etc., and therefore will not be described in detail in this embodiment.

[0020] The kale high-calcium bean curd wet film dewatering device and process provided by this invention are mainly applied to the continuous dewatering treatment of plant-based protein wet films (such as functional bean curd, bean curd sheets, vegetarian chicken films, etc.) containing high-fiber, high-calcium and other nutritionally fortified components. It is understood that the above technical solution can also be applied to the dewatering process of other food or bio-gel film materials with similar physical properties (such as high moisture content, low mechanical strength, and easy adhesion), such as high-moisture plant-based meat molding films, algae protein films, or whey protein gel sheets, and its application scope should not be limited to the specific embodiments listed herein.

[0021] Furthermore, as is common knowledge in this field, the flexible conveyor belts (such as silicone-coated polyester conveyor belts), variable frequency vacuum pumps, clean compressed air sources, high-speed electromagnetic pulse valves, servo motor drive systems, and PLC automatic control units mentioned above are all conventional components in the food machinery industry. Their structures, working principles, and selection methods have been fully disclosed in relevant technical literature and engineering practices. Therefore, the specific construction and control logic of these general components will not be elaborated upon in this article.

[0022] Example 1 This embodiment discloses a dewatering device for a high-calcium kale and bean curd wet film, aiming to solve the problems mentioned in the background art, such as the fragile structure of the wet film, strong liquid bridge adsorption, and damage and nutrient loss caused by continuous negative pressure. This device achieves a balance between efficient dehydration and zero-damage protection under continuous moving conditions through a synergistic mechanism of "negative pressure suction and positive pressure pulse". Specifically: The draining device includes a conveyor belt 1 for transporting the wet tofu skin film. The conveyor belt 1 is a porous, flexible mesh belt, specifically made of food-grade silicone-coated polyester material. Its surface has uniformly distributed micropores with a diameter of 0.4 mm, ensuring sufficient air permeability to support moisture drainage while also possessing low surface energy to reduce adhesion. The wet film falls directly onto the mesh belt from the film-forming machine outlet and is conveyed forward at a uniform speed, entering the working chamber 2 area below. Specifically, the working chamber 2 of the conveyor belt 1 is only located below the incoming section, with its execution surface facing the lower surface of the incoming section, for draining the wet tofu skin film passing through this area; the return section does not have a working chamber 2 to avoid ineffective energy consumption and structural interference.

[0023] Preferred, see Figure 1 , Figure 2 The conveyor belt 1 has a working cavity 2 below it along its own conveying direction. The execution surface of the working cavity 2 faces the lower surface of the conveyor belt 1. The working cavity 2 has a hollow structure inside and is connected to the micropores of the flexible mesh belt through the top opening (execution surface) to form a gas-liquid channel.

[0024] The key improvement is: see: Figure 2 The working chamber 2 is equipped with control components, including a negative pressure interface 3 and a positive pressure interface 4, both of which communicate with the interior of the working chamber 2. The bottom surface of the working chamber 2 is designed as an inclined surface 27 with an inclination angle of 5°. The negative pressure interface 3 is located at the lower end of the inclined surface 27, and the positive pressure interface 4 is located at the higher end. The negative pressure interface 3 is connected to a negative pressure generator (variable frequency vacuum pump), which is adjustable within the range of -0.8 kPa to -2.5 kPa, used to establish a negative pressure environment within the working chamber 2 to draw moisture from the wet film of the tofu skin through the holes of the flexible mesh belt. The positive pressure interface 4 is connected to a positive pressure generator (clean compressed air source), used to introduce gas into the working chamber 2, causing the wet film of the tofu skin to temporarily detach from the surface of the flexible mesh belt, thereby eliminating liquid bridge adsorption and alleviating structural stress caused by continuous adhesion. The compressed air source is equipped with a high-speed electromagnetic pulse valve for outputting instantaneous positive pressure pulses.

[0025] In actual operation, when the wet membrane of dried bean curd enters the coverage area of ​​the working chamber 2, the system first enters the negative pressure stage: the vacuum pump starts, and a stable negative pressure is formed in the working chamber 2. Under the pressure difference, moisture migrates from the inside of the wet membrane through the capillary pores of the protein network to the surface, and then passes through the micropores of the flexible mesh belt into the chamber, and is finally drawn away. However, if only the negative pressure is maintained, the wet membrane will form a liquid bridge with the mesh belt due to its high water content, generating a strong capillary adsorption force, causing it to be "nailed" to the mesh belt during its movement. Once it encounters a mesh belt seam or tension fluctuation, local tensile stress can easily cause microcracks. Therefore, unlike the traditional production line that only relies on intermittent negative pressure strategy, this embodiment innovatively introduces periodic positive pressure pulses in the negative pressure cycle: clean gas is injected into the working chamber 2 from the positive pressure interface 4 and sprayed upward through the micropores of the mesh belt. The gas forms an instantaneous air cushion between the wet membrane and the mesh belt, effectively cutting off the liquid bridge and making the wet membrane briefly "suspended". The wet membrane completely detaches from the support surface, releasing accumulated mechanical stress and preventing localized over-dehydration or structural collapse caused by continuous adhesion. It's important to emphasize that the positive pressure pulse, which "blows" the wet membrane up, is only used to decouple the interface and does not interfere with the overall conveying rhythm. After the pulse ends, the negative pressure immediately returns to continue dehydration. This cycle repeats, allowing the wet membrane to complete drainage in a dynamic balance of adsorption and desorption, ensuring dehydration efficiency, significantly improving integrity, and increasing chlorophyll retention, resulting in a bright green product.

[0026] Example 2 This embodiment discloses a draining device for a wet film of kale and high-calcium bean curd, which is suitable for production line scenarios with higher requirements for compact pipeline layout; it mainly achieves automatic periodic switching between negative and positive pressure through mechanical rotary air circuit switching, without the need for a high-frequency solenoid valve (Embodiment 1).

[0027] The draining device also includes a porous flexible mesh belt (structure same as in Embodiment 1) and a working chamber 2 located below it. Unlike Embodiment 1, in this embodiment, the negative pressure interface 3 and the positive pressure interface 4 are both located at the same end of the working chamber 2, and are alternately connected to the negative pressure generator (variable frequency vacuum pump) and the positive pressure generator (clean compressed air source) through a rotating mechanism, enabling the working chamber 2 to periodically switch between negative and positive pressure states. Specifically: See Figure 3 , Figure 4 The working chamber 2 includes a fixed chamber 21 and a rotating joint 22. The rotating joint 22 is rotatably mounted on the fixed chamber 21 via a rotating shaft and is driven by a servo motor. The rotational speed of the rotating joint 22 is synchronized with the speed of the conveyor belt 1 (for example, each rotation corresponds to a section of wet film passing through). A docking window 23 penetrating the wall of the fixed chamber 21 is provided on the contact surface between the fixed chamber 21 and the rotating joint 22.

[0028] Preferred, see Figure 4The contact area between the fixed cavity 21 and the rotary joint 22 is provided with a docking window 23. Both the negative pressure interface 3 and the positive pressure interface 4 are located on the rotary joint 22. The contact area between the rotary joint 22 and the fixed cavity 21 is circumferentially divided into a negative pressure region 24 and a positive pressure region 25: the negative pressure interface 3 is arc-shaped and located in the negative pressure region 24, while the positive pressure interface 4 is a point or a short arc segment located in the positive pressure region 25. When the rotary joint 22 rotates at a constant angular velocity, the docking window 23 on the fixed cavity 21 sequentially connects with the negative pressure region 24 and the positive pressure region 25 on the rotary joint 22. It is worth noting that as the negative pressure area 24 gradually overlaps with the docking window 23, the connecting area increases from small to large, causing the negative pressure state in the working chamber 2 to gradually increase with the increase of the overlapping area, thus achieving a gentle suction of the wet film. The structural design of the fixed chamber 21 and the rotating joint 22 can effectively suppress the instantaneous impact of negative pressure, avoid local stretching of the wet film, micropore tearing, or loss of functional components due to sudden pressure changes, and also eliminate the need to rely on an additional electronic control valve to throttle and regulate the negative pressure. When the rotating joint 22 continues to rotate until the positive pressure area 25 is aligned with the docking window 23, the positive pressure gas is instantaneously injected into the working chamber 2 and ejected upward through the micropores of the flexible mesh belt, forming an instantaneous micro-air gap between the tofu skin wet film and the mesh belt, causing the wet film to temporarily detach from the support surface, effectively relieving liquid bridge adsorption and releasing accumulated stress.

[0029] In addition, the bottom surface of the working chamber 2 has at least one slope 26, which is inclined along the rotation direction of the rotary joint 22 to guide the condensate or residual water generated during operation to the lowest point (usually located below the negative pressure area 24) and discharge it through the drain port to prevent liquid retention from affecting the rotary seal performance.

[0030] Example 3 This embodiment discloses a drainage process for a kale high-calcium bean curd wet film, which uses the drainage device described in Embodiment 1 (i.e., the structure in which negative pressure interface 3 and positive pressure interface 4 are respectively located at both ends of the working cavity 2). The drainage process includes the following steps: Step S1: The kale high-calcium bean curd wet film with a moisture content of 75%–80% is smoothly transferred from the outlet of the film forming machine to the porous flexible mesh belt, and conveyed at a uniform speed with the mesh belt into the working chamber 2 coverage area.

[0031] Step S2: The control system alternately starts the negative pressure generator and the positive pressure generator according to a preset cycle. Specifically, each working cycle is 8 seconds: the negative pressure generator is started for the first 7.85 seconds, and then switched to the positive pressure generator for the next 0.15 seconds.

[0032] During the negative pressure stage, the variable frequency vacuum pump connected to the negative pressure interface 3 at the lower end of the inclined surface 27 is started, and a stable negative pressure is established in the working chamber 2. Driven by the pressure difference, moisture migrates from the inside of the wet film through the capillary pores of the soybean protein network to the surface, and enters the chamber through the 0.4mm micropores of the flexible mesh belt. Since the bottom surface of the chamber is inclined at 5°, the discharged condensate and residual liquid flow naturally along the slope 26 to the lower drain outlet, achieving centralized discharge and avoiding liquid backflow.

[0033] During the positive pressure phase, the positive pressure port 4, located at the high end of the inclined surface 27, opens, and clean compressed air is instantaneously injected into the working chamber 2 via a high-speed electromagnetic pulse valve. This air is then ejected upwards through the micro-pores of the mesh belt, creating a momentary micro-air gap between the wet film and the mesh belt that lasts approximately 0.15 seconds. This air gap effectively cuts off the liquid bridge, allowing the wet film to briefly detach from the support surface, releasing the mechanical stress accumulated due to continuous adsorption, and preventing edge curling or micro-pore tearing.

[0034] Example 4 This embodiment discloses a drainage process for a kale high-calcium bean curd wet film, using the drainage device described in Embodiment 2 (i.e., a structure that uses a rotating joint 22 to achieve air path switching). The drainage process includes the following steps: Step S1: The kale high-calcium bean curd wet film with a moisture content of 75%–80% is smoothly transferred from the outlet of the film forming machine to the porous flexible mesh belt, and conveyed at a uniform speed with the mesh belt into the working chamber 2 coverage area.

[0035] Step S2: The synchronously driven rotary joint 22 rotates at a constant angular velocity (matching the time it takes for the wet membrane to pass through). The negative pressure region 24 (arc-shaped distribution, occupying at least 180° circumferentially) on the rotary joint 22 first overlaps with the docking window 23 on the fixed cavity 21, and the connecting area gradually increases from zero, causing the negative pressure in the working cavity 2 to rise smoothly from zero. This "gradual increase in negative pressure" process achieves gentle suction of the wet membrane, avoiding the local water flow concentration and structural impact caused by the traditional sudden application of negative pressure.

[0036] Subsequently, the rotary joint 22 continues to rotate, and the negative pressure area 24 completely disengages from the docking window 23. After a brief transition, the positive pressure area 25 (point-like interface) aligns with the docking window 23, and clean gas is instantly injected into the working chamber 2. The gas is ejected upwards through the micropores of the mesh belt, forming a micro-air gap at the bottom of the wet film, causing it to be temporarily suspended, releasing the liquid bridge adsorption, and releasing stress. The rotary joint 22 continues to rotate, completing a full cycle. The working chamber 2 periodically experiences state switching of "gradually increasing negative pressure, maintaining negative pressure, positive pressure pulse, and brief isolation." During this process, the wet film always moves smoothly with the mesh belt without additional vibration or pulling. At the same time, the slope 26 of the bottom surface of the working chamber 2 (inclined at 5° along the direction of rotation) guides the moisture generated during operation to collect at the lowest point and discharges it through the drain outlet located below the negative pressure area 24, ensuring that the rotating sealing surface is dry and clean and maintaining the reliability of the gas path switching.

[0037] Of course, the above are just typical examples of the present invention. In addition, the present invention may have many other specific embodiments. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.

Claims

1. A draining device for a wet film of kale and high-calcium dried bean curd, characterized in that, Includes a conveyor belt for transporting wet tofu skin, said conveyor belt being a porous flexible mesh belt to allow moisture to drain from the wet tofu skin through the holes during transport; The conveyor belt has a working cavity below it along its own conveying direction, and the execution surface of the working cavity faces the lower surface of the conveyor belt; When the working chamber is under negative pressure, the flexible mesh belt applies a downward suction force to the tofu skin wet film, accelerating the migration and removal of moisture inside the tofu skin wet film. When the working chamber is under positive pressure, the gas is ejected upward through the holes, forming a momentary micro-air gap between the wet film of dried bean curd and the flexible mesh belt, so as to release the adsorption of liquid bridge and avoid structural damage to the wet film due to continuous adhesion.

2. The draining device as described in claim 1, characterized in that, The working chamber is equipped with a control component, which includes a negative pressure interface and a positive pressure interface communicating with the interior of the working chamber. The negative pressure interface is connected to a negative pressure generator, which is used to create a negative pressure environment in the working chamber so as to draw out the moisture in the wet film of the dried bean curd through the holes of the flexible mesh belt. The positive pressure interface is connected to a positive pressure generator, which is used to introduce gas into the working chamber, so that the wet film of the dried bean curd sticks temporarily detaches from the surface of the flexible mesh belt, thereby eliminating liquid bridge adsorption and relieving the structural stress caused by continuous adhesion.

3. The draining device as described in claim 2, characterized in that, The negative pressure interface and the positive pressure interface are respectively and independently arranged at both ends of the working cavity; The bottom surface of the working chamber is an inclined surface, the negative pressure interface is located at the lower end of the inclined surface, and the positive pressure interface is located at the upper end of the inclined surface.

4. The draining device as described in claim 2, characterized in that, The negative pressure interface and the positive pressure interface are both located at the same end of the working chamber; the working chamber is periodically switched between negative pressure state and positive pressure state by the alternating connection between the negative pressure generator and the positive pressure generator.

5. The draining device as described in claim 4, characterized in that, The working cavity includes a fixed cavity and a rotating joint, wherein the rotating joint is rotatably assembled on the fixed cavity; The contact area between the fixed cavity and the rotary joint is provided with a docking window, and the negative pressure interface and the positive pressure interface are provided on the rotary joint; When the rotary joint rotates, the docking window alternately connects with the negative pressure interface or the positive pressure interface in sequence, so that the working chamber periodically switches to a negative pressure state or a positive pressure state.

6. The draining device as described in claim 5, characterized in that, The contact area between the rotary joint and the fixed cavity is divided into a negative pressure area and a positive pressure area along the circumference; the negative pressure interface is distributed in an arc shape on the negative pressure area, and the positive pressure interface is disposed on the positive pressure area; As the rotary joint rotates, the negative pressure area gradually connects with the docking window, causing the negative pressure state in the working cavity to increase with the increase of the overlapping area.

7. The draining device as described in claim 5 or 6, characterized in that, The bottom surface of the working chamber has at least one slope, which is inclined along the direction of the rotary joint to guide condensate or residual moisture to collect and drain into a predetermined area.

8. A draining process for a wet film of high-calcium kale and dried bean curd, using the draining device described in claim 3, characterized in that, The draining process includes the following steps: Step S1: Place the wet film of dried bean curd sticks to be drained on the flexible mesh belt and convey it through the working cavity at a uniform speed with the flexible mesh belt; Step S2: Alternately start the negative pressure generator and the positive pressure generator; When the negative pressure generator is started, the negative pressure interface located at the lower end of the inclined surface draws water into the working chamber, causing the water to be discharged downward through the holes of the flexible mesh belt and flow along the inclined bottom surface of the working chamber to the lower end for centralized discharge. When the positive pressure generator is started, the positive pressure interface located at the high end of the inclined surface introduces gas into the working chamber. The gas is sprayed upward through the holes of the flexible mesh belt, forming an instantaneous micro air gap between the wet film of the bean curd stick and the flexible mesh belt to relieve the adsorption of the liquid bridge. The moisture content of the tofu skin wet film is reduced through the periodic synergistic effect of negative pressure dehydration and positive pressure desorption.

9. A draining process for a wet film of high-calcium kale and dried bean curd, using the draining device described in any one of claims 5 to 7, characterized in that, The draining process includes the following steps: Step S1: Place the wet film of dried bean curd sticks to be drained on the flexible mesh belt and convey it through the working cavity at a uniform speed with the flexible mesh belt; Step S2: Drive the rotary joint to rotate at a constant angular velocity, so that the negative pressure area on the rotary joint is gradually connected with the docking window of the fixed cavity. The negative pressure in the working cavity gradually increases as the connection area increases, so as to achieve gentle suction of the wet film. When the rotary joint continues to rotate until it connects with the docking window in the positive pressure area, positive pressure gas is injected instantaneously, causing the wet film to briefly detach from the surface of the mesh belt. By continuously rotating the rotary joint, the working chamber periodically experiences the switching between gradually increasing negative pressure and positive pressure pulses, thereby reducing the moisture content of the wet film.

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