A low-temperature plasma activated water generating device for preserving soy products

Abstract

The utility model belongs to food preservation equipment technical field, concretely relates to a kind of low temperature plasma activated water generation device for bean product preservation, its structure includes PP container, the upper barrier plate and the lower barrier plate fixed on its upper and lower ends respectively, and high voltage electrode and ground electrode are correspondingly installed on the outside of barrier plate;Upper barrier plate inside is integrated with gas delivery assembly, and the component includes by shunt pipe, short pipe and the low temperature plasma discharge body located above the liquid level of PP container.Concrete working, the mixed gas of oxygen, carbon dioxide and nitrogen is directly sent to the discharge area above liquid level by gas delivery assembly, and low temperature plasma activated water is generated by electrode to generate dielectric barrier discharge effect.By the device processing bean products such as beancurd, shelf life can be extended, while maintaining original sensory quality.Compared with prior art, the device has the advantages of no chemical residues, low energy consumption and easy operation, and is suitable for industrialized preservation treatment of various bean products.

Description

Technical Field

[0001] This utility model belongs to the technical field of food preservation equipment, specifically relating to a low-temperature plasma activated water generation device for preserving bean products. Background Technology

[0002] Soy products, being high in protein, are highly susceptible to spoilage due to microbial growth during storage. Traditional preservation methods primarily employ high-temperature sterilization or the addition of chemical preservatives, but these methods have significant drawbacks: high-temperature treatment can denature proteins, affecting product texture; and chemical additives may pose food safety risks and do not meet modern consumers' demands for food safety. According to statistics from the China Soy Products Association in 2024, the loss rate of soy products due to improper preservation is as high as 12%-15%.

[0003] In recent years, non-thermal sterilization technologies have achieved significant breakthroughs in food preservation, with low-temperature plasma technology attracting considerable attention due to its unique sterilization mechanism. Plasma-activated water (PAW) generates reactive oxygen species (RONS) through dielectric barrier discharge, including hydroxyl radicals, singlet oxygen, hydrogen peroxide, and nitrites. These active substances can effectively penetrate microbial cell membranes, disrupting their DNA and protein structures. Studies have shown that PAW treatment can reduce E. coli in tofu by 4-5 logarithmic cycles while maintaining the integrity of the secondary structure of soybean protein.

[0004] However, existing PAW equipment faces three major technical bottlenecks in practical applications: First, the gas utilization rate is low, with traditional bubbling methods achieving less than 30% gas utilization; second, the electrodes are prone to corrosion, resulting in a service life of only 200-300 hours; and third, there is a lack of dynamic gas ratio adjustment functionality. To address these issues, this device utilizes innovative solutions such as optimized electrode design and integrated gas control valves and spray components.

[0005] It is particularly important to note that the gas composition has a decisive influence on the properties of PAW (Polymerized Water Activated by Plasma) products. Research published in *Innovative Food Science & Emerging Technologies* (2024) shows that PAW generated using a mixture of O2 / N2 / CO2 (65% / 30% / 5%) gas can achieve an oxidation-reduction potential (ORP) exceeding +450mV, and its inhibitory effect on mold is three times better than that of pure air treatment. However, existing equipment generally uses a fixed-ratio gas supply system, which cannot achieve dynamic adjustment of the gas composition. This severely limits the application effect of PAW technology in the preservation of soy products. Therefore, developing a dedicated device that can efficiently and uniformly generate low-temperature plasma-activated water and is suitable for the preservation of soy products has become a pressing technical challenge for the soy product industry. Utility Model Content

[0006] The purpose of this invention is to provide a low-temperature plasma activated water generation device for preserving soy products, so as to solve the problem of low generation efficiency mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a low-temperature plasma activated water generation device for preserving bean products, comprising a lower baffle plate, a PP container fixed to the top of the lower baffle plate, and an upper baffle plate fixed to the top of the PP container, wherein the upper baffle plate has a cavity inside.

[0008] The grounding electrode is fixed below the lower barrier plate;

[0009] A high-voltage electrode is fixed above the upper barrier plate. The high-voltage electrode and the grounding electrode together constitute an electrode system for generating plasma discharge above the liquid surface in the PP container.

[0010] A gas delivery assembly, disposed on the upper barrier plate, is used to deliver a mixed gas containing oxygen, carbon dioxide, and nitrogen to the discharge area formed by the electrode system. The gas delivery assembly includes:

[0011] The diversion pipe is installed laterally in the cavity;

[0012] At least one short pipe, one end of which is connected to the branch pipe;

[0013] A low-temperature plasma discharge body is horizontally fixed to the other end of the at least one short tube and located above the liquid surface in the PP container, for uniformly releasing gas from the shunt tube to the discharge area.

[0014] And a precisely calibrated gas proportional control valve installed on the outside of the upper barrier plate, the gas proportional control valve being connected to the split pipe and used to regulate the gas flow rate entering the split pipe.

[0015] Furthermore, one side of the gas proportional control valve is connected to the split pipe, and the short pipe is connected between the split pipe and the low-temperature plasma discharge body, forming a fluid passage for transporting the mixed gas containing oxygen, carbon dioxide and nitrogen.

[0016] Furthermore, the device also includes an electrode spacing adjustment mechanism, which includes a support frame fixed to the lower barrier plate and a connecting component connected to the ground electrode and the high voltage electrode and movable relative to the support frame.

[0017] Furthermore, a plug rod is fixed on the support frame, and the connecting assembly includes a connecting rod connected to the ground electrode and the high-voltage electrode, and a sleeve fixed on the connecting rod. The sleeve is movably inserted into the plug rod, so that the sleeve can move vertically along the outer wall of the plug rod.

[0018] Furthermore, the sleeve is threaded with a bolt, which is used to lock the sleeve in a preset position on the insert rod.

[0019] Furthermore, the grounding electrode and the high-voltage electrode are fitted with outer covers for electrical insulation and stabilizing the electric field, and the grounding electrode and the high-voltage electrode are respectively fixed with terminals for connecting the power supply through the outer covers.

[0020] Furthermore, the device also includes a fan-shaped spray treatment assembly, which includes a suction tube whose lower opening is located inside the PP container, and a liquid pump fixed to the outside of the PP container and whose inlet is connected to the upper end of the suction tube.

[0021] Furthermore, the fan-shaped spray treatment assembly also includes a hose with one end connected to the outlet of the liquid pump, and a fan-shaped spray head fixed to the other end of the hose.

[0022] Furthermore, a support rod is fixed to the outside of the PP container, and the support rod is provided with a slot for receiving the hose and the fan-shaped spray head.

[0023] Furthermore, the electrode system is also connected to a pulse frequency adjustment module, which is used to adjust the voltage frequency applied between the high-voltage electrode and the ground electrode to optimize the generation of active substances.

[0024] Compared with the prior art, the beneficial effects of this utility model are:

[0025] (1) This utility model provides a low-temperature plasma activated water generation device for preserving soy products, which uses low-temperature plasma activated water technology to sterilize the surface of soy products. Compared with traditional methods, it avoids protein denaturation and taste deterioration caused by traditional high-temperature treatment, and eliminates the food safety risks caused by chemical preservatives, thus maximizing the preservation of the original nutrition and appearance quality of soy products.

[0026] (2) This utility model provides a low-temperature plasma activated water generation device for preserving soy products. Its innovation lies in the configuration of a high-precision gas proportioning control valve, which can accurately adjust the O2 / CO2 / N2 mixing ratio to promote the generation of nitrogen species (RONS) with strong antibacterial activity; the use of an adjustable electrode design, which changes the electric field strength of the discharge gap by adjusting the electrode spacing; and the support for pulse frequency adjustment, which can accurately control the proportion of active species generated. This design enables the device to customize the production of activated water with specific pH values, conductivity and RONS components according to different types of soy products such as tofu and dried tofu, and also enhances the flexibility and applicability of the device.

[0027] (3) This utility model provides a low-temperature plasma activated water generation device for the preservation of bean products. It integrates a fan-shaped spray treatment component including a liquid pump, hose, fan-shaped spray head, and a storage structure including a support rod and a slot. This device integrates the functions of activated water generation, extraction, distribution, and storage into one compact structure with a simple operation process. Simultaneously, the device uses a fan-shaped spray head to spray the generated activated water, ensuring uniform and thorough coverage of the bean product surface, guaranteeing consistent treatment results and avoiding the unevenness issues of traditional treatment methods. Combined with the activated water generation system, this device fully meets the needs of industrialized production line operations for bean products, significantly improving the efficiency of bean product preservation.

[0028] (4) This utility model provides a low-temperature plasma activated water generation device for preserving bean products. The device adopts a modular design and has a compact structure. The high-voltage components are wrapped with a PP material outer cover, which ensures operational safety and effectively prevents equipment corrosion. The outer cover also helps to confine the electric field, reduce energy dissipation, and make the discharge more stable and efficient. The integrated liquid extraction, distribution, and storage functions simplify the overall operation process. Compared with the prior art, it has the comprehensive advantages of low energy consumption, no chemical residue, and low maintenance cost. Attached Figure Description

[0029] Figure 1 This is a front view cross-sectional structural diagram of the present invention;

[0030] Figure 2 This is a front view cross-sectional structural diagram of the PP container of this utility model;

[0031] Figure 3 This is a front view cross-sectional structural diagram of the outer cover of this utility model;

[0032] Figure 4 This is a front view cross-sectional structural diagram of the support rod of this utility model.

[0033] In the diagram: 1. Lower baffle plate; 2. PP container; 3. Grounding electrode; 4. Terminal; 5. Outer cover; 6. Connecting rod; 7. Sleeve; 8. Bolt; 9. Insert rod; 10. Support frame; 11. Screw hole; 12. Upper baffle plate; 13. Low-temperature plasma discharge body; 14. High-voltage electrode; 15. Cavity; 16. Diverter pipe; 17. Short pipe; 18. Gas proportional control valve; 19. Hose; 20. Through groove; 21. Support rod; 22. Cover; 23. Fan-shaped spray head; 24. Slot; 25. Suction pipe; 26. Liquid pump. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0035] like Figures 1 to 4 An embodiment of this utility model is provided: a low-temperature plasma activated water generation device for preserving bean products, including a lower baffle plate 1, a PP container 2 fixed to the top of the lower baffle plate 1, and an upper baffle plate 12 fixed to the top of the PP container 2. A gas proportioning control valve 18 is installed on the left side of the upper baffle plate 12. A cavity 15 is provided inside the upper baffle plate 12, and a diversion pipe 16 is installed horizontally in the cavity 15. A short pipe 17 is fixed to the bottom of the diversion pipe 16, and a low-temperature plasma discharge body 13 is fixed horizontally between the bottoms of the short pipes 17.

[0036] The right side of the gas proportional control valve 18 is connected to the split pipe 16, and the short pipe 17 is connected between the split pipe 16 and the low-temperature plasma discharge body 13.

[0037] The core working principle of this device is dielectric barrier discharge (DBD). DBD is an effective way to generate low-temperature plasma under high pressure (such as atmospheric pressure). In this embodiment, a high-frequency AC voltage is applied between the high-voltage electrode 14 and the ground electrode 3, and the wall of the PP container 2 or an additional insulating layer acts as a barrier medium. The function of this dielectric layer is to prevent the current from increasing indefinitely, thereby avoiding the formation of an electric arc and ensuring the generation of "cold" plasma with a temperature close to room temperature.

[0038] The specific reaction process and principle are as follows:

[0039] When the voltage between the electrodes reaches the breakdown voltage of the gas, the mixture of air, carbon dioxide, and water vapor in the discharge region is ionized. High-energy electrons in the electric field undergo inelastic collisions with neutral gas molecules (such as N2, O2, CO2, and H2O). These collisions cause the gas molecules to be excited, dissociated, and ionized, producing a large number of highly chemically reactive particles, collectively known as reactive oxygen species (ROS) and reactive nitrogen species (RONS), including but not limited to hydroxyl radicals (·OH), atomic oxygen (·O), ozone (O3), hydrogen peroxide (H2O2), and nitrogen oxides (NO). x These reactions form the chemical basis for the generation of activated water. In this device, the low-temperature plasma discharger 13 is placed immediately adjacent to the liquid surface inside the PP container 2. This design allows the generated RONS to dissolve and diffuse rapidly and efficiently into the water, further reacting with water molecules to alter the water's pH, conductivity, redox potential, and other physicochemical properties, ultimately forming activated water with specific biochemical activities.

[0040] Specifically, such as Figure 1 and Figure 2 As shown, the left side of the gas proportional control valve 18 is connected to an external pipeline. After opening the gas proportional control valve 18, a mixed gas containing oxygen, carbon dioxide and trace amounts of nitrogen, prepared according to a preset ratio, can be injected into the diversion pipe 16 of the cavity 15. Then, it flows into the low-temperature plasma discharge body 13 through each short pipe 17. The low-temperature plasma discharge body 13 at the bottom of the short pipe 17 is attached to the liquid surface of the PP container 2. After connecting the power supply at the high-voltage electrode 14 and the grounding electrode 3, the activated water production operation can be carried out, eliminating the reaction time between gas and water in this process.

[0041] A grounding electrode 3 is fixed below the lower baffle plate 1, and a high-voltage electrode 14 is fixed above the upper baffle plate 12. An outer cover 5 is sleeved around the grounding electrode 3 and the high-voltage electrode 14. A connecting rod 6 is fixed to the right side of the outer cover 5. A sleeve 7 is fixed longitudinally on the surface of the connecting rod 6. An insert rod 9 is movably inserted at the center between the upper and lower sleeves 7. Screw holes 11 are arranged between the upper and lower parts inside the insert rod 9. A support frame 10 is fixed to the right side of the top of the lower baffle plate 1. A through groove 20 is provided inside the top of the support frame 10. A bolt 8 is threaded to the front end of the sleeve 7. Terminals 4 are fixed through the outer cover 5 to the grounding electrode 3 and the high-voltage electrode 14. The insert rod 9 is fixedly connected in the through groove 20. The sleeve 7 moves vertically along the outer wall of the insert rod 9.

[0042] Specifically, such as Figure 1 and Figure 3As shown, along the insertion rod 9 fixed by the support frame 10, adjust the positions of the upper and lower sleeves 7, and then align them with the screw holes 11 on the surface of the insertion rod 9 and screw in the bolts 8 for reinforcement. This can prevent the sleeves 7 from continuing to slide along the insertion rod 9, thereby achieving the purpose of adjusting the distance between the upper and lower high voltage electrodes 14 and the grounding electrode 3. Furthermore, the exterior of the high voltage electrodes 14 and the grounding electrode 3 is wrapped and protected by the outer cover 5.

[0043] In addition, the electrode system is connected to a pulse frequency adjustment module (not shown in the figure), which is used to adjust the voltage frequency applied between the high-voltage electrode 14 and the ground electrode 3, preferably in the range of 20-50 kHz. By coordinating the adjustment of the electrode spacing and the pulse frequency, the discharge intensity and energy of the plasma can be precisely controlled, thereby optimizing the generation spectrum of active substances to obtain the optimal activated water for different soy product preservation needs.

[0044] A straw 25 is fixed inside the upper left corner of the PP container 2, a liquid pump 26 is fixed outside the upper left corner of the PP container 2, a hose 19 is fixed to the left side of the liquid pump 26, a fan-shaped spray head 23 is fixed to the end of the hose 19, and a cover 22 is movably connected to the surface of the fan-shaped spray head 23. A support rod 21 is fixed at the center of the left side of the outside of the PP container 2, and a slot 24 is provided inside the left side of the support rod 21. The hose 19 is embedded in the slot 24, and the top of the straw 25 is connected to the liquid pump 26.

[0045] Specifically, such as Figure 1 and Figure 4 As shown, the opening of the straw 25 is below the liquid surface of the PP container 2. After the liquid inside is made into low-temperature plasma activated water, the liquid pump 26 can be started to introduce the activated water into the hose 19 through the straw 25. The fan-shaped spray head 23 is removed from the slot 24 of the support rod 21 in advance. Then, the hinged cover 22 is opened so that the fan-shaped spray head 23 can be aligned with the collection container to collect the activated water.

[0046] When used for preserving soy products, this device places tofu and other soy products on a conveyor belt and uses a spray system consisting of a liquid pump 26 and fan-shaped spray nozzles 23 to evenly spray low-temperature plasma-activated water for surface treatment. Tofu treated with this device has a significantly extended shelf life under refrigeration conditions while maintaining its original protein content and texture. During the treatment process, an external control unit can automatically adjust the activation water generation and spray parameters to ensure stable treatment results.

[0047] Working Principle: In use, this invention first adjusts the positions of the upper and lower sleeves 7 along the insertion rod 9 fixed to the support frame 10. Then, aligning with the screw holes 11 on the surface of the insertion rod 9, bolts 8 are screwed in for reinforcement, preventing the sleeves 7 from continuing to slide along the insertion rod 9. This achieves the purpose of adjusting the distance between the upper and lower high-voltage electrodes 14 and the grounding electrode 3. Furthermore, the high-voltage electrodes 14 and the grounding electrode 3 are both encased in an outer cover 5, which does not affect the flow of electricity and facilitates connection to the power supply via the terminal 4. Afterward, the left side of the gas proportional control valve 18 is connected to an external pipeline. After opening and adjusting the gas proportional control valve 18, a mixture of oxygen, carbon dioxide, and nitrogen gas prepared according to a preset ratio can be injected. The liquid enters the shunt tube 16 of the cavity 15 and then flows into the low-temperature plasma discharge body 13 through each short tube 17. The low-temperature plasma discharge body 13 at the bottom of the short tube 17 is attached to the liquid surface of the PP container 2. After the power is turned on at the high voltage electrode 14 and the ground electrode 3, the activated water production operation can be carried out. The opening of the suction tube 25 is located below the liquid surface of the PP container 2. After the liquid inside is made into low-temperature plasma activated water, the liquid pump 26 can be started and the activated water is introduced into the hose 19 through the suction tube 25. The fan-shaped spray head 23 is removed from the slot 24 of the support rod 21 in advance. Then, the hinged cover 22 is opened, and the fan-shaped spray head 23 can be aligned with the collection container to collect the activated water.

[0048] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A low-temperature plasma activated water generation device for preserving bean products, comprising a lower baffle plate (1), characterized in that: The top of the lower barrier plate (1) is fixed with a PP container (2), and the top of the PP container (2) is fixed with an upper barrier plate (12). The upper barrier plate (12) has a cavity (15) inside. The grounding electrode (3) is fixed below the lower barrier plate (1); The high-voltage electrode (14) is fixed above the upper barrier plate (12). The high-voltage electrode (14) and the grounding electrode (3) together constitute an electrode system for generating plasma discharge above the liquid surface in the PP container (2). A gas delivery assembly, disposed on the upper barrier plate (12), is used to deliver a mixed gas containing oxygen, carbon dioxide, and nitrogen to the discharge area formed by the electrode system. The gas delivery assembly includes: The diversion pipe (16) is installed laterally in the cavity (15); At least one short tube (17) has one end connected to the branch tube (16); The low-temperature plasma discharge body (13) is horizontally fixed to the other end of the at least one short tube (17) and located above the liquid surface in the PP container (2) for uniformly releasing gas from the diversion tube (16) to the discharge area. And a precisely calibrated gas proportional control valve (18) installed on the outside of the upper baffle plate (12), the gas proportional control valve (18) being connected to the diverter pipe (16) for regulating the gas flow rate entering the diverter pipe (16).

2. The low-temperature plasma activated water generation device for preserving bean products according to claim 1, characterized in that: One side of the gas proportional control valve (18) is connected to the diverter pipe (16), and the short pipe (17) is connected between the diverter pipe (16) and the low-temperature plasma discharge body (13), forming a fluid passage for transporting the mixed gas containing oxygen, carbon dioxide and nitrogen.

3. The low-temperature plasma activated water generation device for preserving bean products according to claim 1, characterized in that: The device further includes an electrode spacing adjustment mechanism, which includes a support frame (10) fixed on the lower barrier plate (1) and a connecting component connected to the ground electrode (3) and the high voltage electrode (14) and movable relative to the support frame (10).

4. The low-temperature plasma activated water generation device for preserving bean products according to claim 3, characterized in that: The support frame (10) is fixed with a plug rod (9). The connecting assembly includes a connecting rod (6) connected to the grounding electrode (3) or the high voltage electrode (14) and a sleeve (7) fixed on the connecting rod (6). The sleeve (7) is movably inserted into the plug rod (9) and can move vertically along the outer wall of the plug rod (9).

5. A low-temperature plasma activated water generation device for preserving soybean products according to claim 4, characterized in that: The sleeve (7) is threaded with a bolt (8), which is used to lock the sleeve (7) at a preset position on the insert rod (9).

6. The low-temperature plasma activated water generation device for preserving bean products according to claim 1, characterized in that: The grounding electrode (3) and the high voltage electrode (14) are fitted with an outer cover (5) for electrical insulation and stabilizing the electric field. The grounding electrode (3) and the high voltage electrode (14) are respectively fixed with terminals (4) for connecting the power supply through the outer cover (5).

7. The low-temperature plasma activated water generation device for preserving bean products according to claim 1, characterized in that: The device also includes a fan-shaped spray treatment assembly, which includes a suction tube (25) whose lower end opening is located inside the PP container (2), and a liquid pump (26) fixed to the outside of the PP container (2) and whose inlet is connected to the upper end of the suction tube (25).

8. A low-temperature plasma activated water generation device for preserving soybean products according to claim 7, characterized in that: The fan-shaped spray treatment assembly also includes a hose (19) with one end connected to the outlet of the liquid pump (26), and a fan-shaped spray head (23) fixed to the other end of the hose (19).

9. A low-temperature plasma activated water generation device for preserving bean products according to claim 8, characterized in that: The PP container (2) is fixed with a support rod (21) on the outside, and the support rod (21) is provided with a slot (24) for receiving the hose (19) and the fan-shaped spray head (23).

10. A low-temperature plasma activated water generation device for preserving bean products according to claim 1, characterized in that: The electrode system is also connected to a pulse frequency adjustment module for adjusting the voltage frequency applied between the high voltage electrode (14) and the ground electrode (3).

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