Low-viscosity liquid food sterilization device and method

Abstract

The invention relates to a low-viscosity liquid food sterilization device and method, and the low-viscosity liquid food sterilization device comprises a control unit, and a microwave heating unit, a high-voltage pulse electric field unit and a cooling unit which are connected with the control unit; the microwave heating unit, the high-voltage pulse electric field unit and the cooling unit are sequentially connected end to end, and under the control of the control unit, microwave rapid heating sterilization, high-voltage pulse electric field sterilization and low-temperature cooling are sequentially carried out on the low-viscosity liquid food. The invention provides a low-viscosity liquid food sterilization device which can retain the functional nutrition of low-viscosity liquid food, preserve the flavor of the low-viscosity liquid food, thoroughly sterilize, prolong the storage period and improve the production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing devices, and in particular to a low-viscosity liquid food sterilization device and method. Background Art

[0002] Low-viscosity liquid foods, such as water, fresh milk, formula milk powder solution, low-concentration sugar water solution, low-viscosity fruit juice drinks, soda, glucose solution and saline, are rich in nutrients such as protein, fat, lactose, minerals, vitamins, etc. However, such foods are very susceptible to microbial contamination during processing, storage and transportation, resulting in product quality deterioration. Existing food sterilization methods mainly include thermal sterilization and non-thermal sterilization. Thermal sterilization methods include pasteurization, high-temperature short-time sterilization, ultra-high temperature instantaneous sterilization, ohmic sterilization, etc. Although it can effectively kill microorganisms, for foods rich in heat-sensitive nutrients such as protein, vitamins, and unsaturated fatty acids, excessively high sterilization temperatures will lead to loss of food nutrition and flavor. Non-thermal sterilization includes sterilization technologies such as high-voltage pulse electric field technology, ultra-high static pressure technology, microwave irradiation technology, and oscillating magnetic field technology. Taking high-voltage pulse electric field technology as an example, the Chinese patent with publication number CN212014312U discloses a high-voltage pulse electric field milk sterilization device, which uses a high-voltage pulse electric field to sterilize milk. This non-thermal sterilization cannot completely eliminate corruption and pathogenic microorganisms, and is therefore difficult to adapt to industrial and large-scale applications.

[0003] Therefore, how to provide a device that can retain the functional nutrition of low-viscosity liquid food, preserve the flavor of low-viscosity liquid food, and can thoroughly sterilize, improve the storage period and production efficiency, is a technical problem that needs to be urgently solved in this field. Summary of the invention

[0004] In order to solve at least one of the above technical problems, the present invention provides a low-viscosity liquid food sterilization device, comprising: a control unit, and a microwave heating unit, a high-voltage pulse electric field unit and a cooling unit connected to the control unit;

[0005] The microwave heating unit, the high-voltage pulse electric field unit and the cooling unit are connected end to end in sequence, and under the control of the control unit, they respectively perform the following on the low-viscosity liquid food: microwave rapid heating sterilization, high-voltage pulse electric field sterilization and low-temperature cooling.

[0006] Further, the microwave heating unit comprises: a tunnel-type microwave cavity, a spiral glass tube and a microwave generator;

[0007] A spiral glass tube is arranged inside the tunnel-type microwave cavity;

[0008] The microwave generator is arranged on the tunnel type microwave cavity and faces the spiral glass tube.

[0009] Furthermore, the high-voltage pulsed electric field unit includes: multiple high-voltage pulsed electric field pipes connected in parallel;

[0010] The high-voltage pulsed electric field pipe includes: a high-voltage electric field pulse generator, a plate, and a first liquid flow pipe arranged at intervals;

[0011] The plate is arranged on both sides of the first liquid flow pipe and is connected to both poles of the high-voltage electric field pulse generator respectively.

[0012] Furthermore, the high-voltage electric field pulse generator includes: a power supply, a voltage transformation switch, and a transformer connected to the plate, which are connected in sequence;

[0013] The voltage transformation switch is used to control the opening and closing of the power supply;

[0014] The transformer includes: an iron core assembly, a primary coil winding, a secondary coil winding, and a base;

[0015] The iron core assembly is provided with a first cylindrical core on the upper side, a second cylindrical core on the lower side, and both left and right ends are embedded in the base;

[0016] The primary coil winding is arranged on the second cylindrical core;

[0017] The secondary coil winding is arranged on the first cylindrical core.

[0018] Furthermore, the first cylindrical core includes: a winding winding space and an electrical isolation interval space divided by multiple plates;

[0019] For the winding winding space and the electrical isolation interval space, lead-out notches are provided on adjacent plates, and two adjacent lead-out notches are arranged radially staggered;

[0020] One end of the insulating enameled wire of the secondary coil winding is connected from the terminal beside the first winding winding space, winds in the first winding winding space, then passes through the lead-out notch and enters the next winding winding space to wind, and finally winds out from the terminal beside the last winding winding space.

[0021] Furthermore, multiple insulating circles for spacing are provided inside the insulating enameled wire wound in the winding winding space;

[0022] Insulating resin is poured into the winding winding space and the electrical isolation interval space.

[0023] Furthermore, the high-voltage electric field pulse generator further includes: a voltage multiplier module arranged at the rear end of the transformer;

[0024] The voltage multiplier module includes: a capacitor voltage multiplier circuit, a first side voltage output terminal, and a first input terminal and a second input terminal arranged on the second side;

[0025] A voltage output terminal, connected to the plate

[0026] A first input terminal and a second input terminal, connected to both ends of the transformer

[0027] Furthermore, a cooling unit, comprising: a plate-frame cooler, a cooling pipeline arranged on the plate-frame cooler, and a second liquid flow pipeline arranged inside the plate-frame cooler

[0028] One end of the second liquid flow pipeline is connected to the first liquid flow pipeline, and the other end is provided with a discharge port

[0029] Furthermore, a control unit, comprising: a monitoring and data acquisition module, a central control module, a motion module, and a human-machine interface that are interconnected

[0030] The monitoring and data acquisition module collects and monitors the material temperature in the microwave heating unit, the material temperature in the cooling unit, and the voltage of the high-voltage electric field pulse unit, and simultaneously collects and monitors the material flow rates of the microwave heating unit, the high-voltage pulse electric field unit, and the cooling unit

[0031] The motion module is used to adjust the material flow rate and the opening and closing state of the material in the microwave heating unit, the high-voltage electric field pulse unit, and the cooling unit

[0032] The central control module uses the data collected by the monitoring and data acquisition module, combines the instructions input by the human-machine interface, and adjusts the output power and material flow rate of the microwave heating unit, the high-voltage electric field pulse unit, and the cooling unit

[0033] The human-machine interface is used to input control instructions and display the data and working status collected by the monitoring and data acquisition module, the motion module, and the central control module

[0034] A method for sterilizing low-viscosity liquid food, using any of the above-mentioned low-viscosity liquid food sterilization devices, the steps include: First, the monitoring and data acquisition module of the control unit performs data acquisition, simulation, and emulation

[0035] Then, the distributed control module and the central control module control the microwave heating unit, the high-voltage pulse electric field unit, and the cooling unit through the input logical operation instructions and timer / counter instructions

[0036] Next, the low-viscosity liquid food is introduced into the microwave heating unit; the microwave heating unit adjusts the microwave generation power, the low-viscosity liquid food flow rate, and the low-viscosity liquid food temperature to preset values

[0037] Then, the ambient temperature of the high-voltage pulse electric field unit is adjusted to be consistent with the liquid food temperature at the feed inlet, and different preset electric field intensities are adopted according to the type of low-viscosity liquid food

[0038] Finally, the low-viscosity liquid food is introduced into the cooling unit. After cooling, the above sterilization process is repeated or aseptic filling is carried out according to the sterilization effect.

[0039] In this embodiment, a sterilization device for low-viscosity liquid food is provided. When in use, first, the low-viscosity liquid food is introduced into the microwave heating unit. Microwave heating can raise the temperature of the low-viscosity liquid food to the temperature required for sterilization within a short time, sterilize the low-viscosity liquid food, effectively kill most microorganisms, and at the same time maintain the flavor and nutritional components of the food. Then, the low-viscosity liquid food is introduced into the high-voltage pulsed electric field unit. The high-voltage pulsed electric field destroys the cell membrane of microorganisms, making them lose their activity, thereby further reducing the number of microorganisms in the food, ensuring food safety, and at the same time not causing an obvious thermal effect, and better maintaining the original quality and flavor of the food. Finally, the low-viscosity liquid food after sterilization enters the cooling unit. Through rapid cooling, the food temperature is reduced, preventing the loss of flavor and nutrients caused by high temperature, and improving the storage stability of the food. At the same time, using instantaneous low temperature, some microorganisms are killed again. Moreover, due to the use of the fluidity of the low-viscosity liquid food by this device, the low-viscosity liquid food can be continuously processed, greatly improving the production efficiency. It should be noted that for the low-viscosity liquid food cooled by the cooling unit, the operator can directly export and store it according to actual needs, or re-introduce the processed low-viscosity food into the microwave heating unit for multiple cycle processing. In addition, the sterilization device for low-viscosity liquid food provided by the present invention can also be used for the sterilization of other liquid foods with fluidity or liquid materials with fluidity. The sterilization device for low-viscosity liquid food provided by the present invention especially utilizes the rapid heating of the microwave heating unit, the rapid discharge of the high-voltage pulsed electric field unit, and the rapid cooling of the cooling unit. Under the drastic environmental changes, it can more effectively kill microorganisms and ensure the food flavor. In summary, the present invention provides a sterilization device for low-viscosity liquid food, which can retain the functional nutrition of the low-viscosity liquid food, preserve the flavor of the low-viscosity liquid food, and can thoroughly sterilize, improving the storage period and production efficiency. Description of the Drawings

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the structures shown in these drawings. In the drawings, the same components are denoted by the same reference numerals. The drawings are not drawn to actual scale.

[0041] Figure 1Schematic diagram of an embodiment of a low-viscosity liquid food sterilization device of the present invention;

[0042] Figure 2 Cross-sectional view of an embodiment of a microwave heating unit of a low-viscosity liquid food sterilization device of the present invention;

[0043] Figure 3 Schematic diagram of an embodiment of a high-voltage pulsed electric field unit of a low-viscosity liquid food sterilization device of the present invention;

[0044] Figure 4 Schematic diagram of an embodiment of a high-voltage electric field pulse generator of a Fenton low-viscosity liquid food sterilization device of the present invention;

[0045] Figure 5 Schematic diagram of an embodiment of a secondary coil winding of a Fenton low-viscosity liquid food sterilization device of the present invention;

[0046] Figure 6 For Figure 5 Schematic diagram of the A-A cross-section of;

[0047] Figure 7 Exploded view of an embodiment of a transformer of a Fenton low-viscosity liquid food sterilization device of the present invention;

[0048] Figure 8 Schematic diagram of an embodiment of an iron core assembly of a Fenton low-viscosity liquid food sterilization device of the present invention;

[0049] Figure 9 Schematic diagram of an embodiment of an insulating ring of a Fenton low-viscosity liquid food sterilization device of the present invention;

[0050] Figure 10 Schematic diagram of another embodiment of a secondary coil winding of a Fenton low-viscosity liquid food sterilization device of the present invention;

[0051] Figure 11 Schematic diagram of an embodiment of a voltage multiplier module of a Fenton low-viscosity liquid food sterilization device of the present invention;

[0052] Figure 12 Schematic diagram of an embodiment of a first rectifying circuit and a second rectifying circuit of a Fenton low-viscosity liquid food sterilization device of the present invention. Detailed implementation manners

[0053] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0054] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may be a middle element at the same time. When an element is referred to as "connected" to another element, it can be directly connected to the other element or there may be a middle element at the same time.

[0055] It should also be noted that if there are directional indications involved in the embodiments of the present invention, such as up, down, left, right, front, back..., then the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly. In addition, if there are descriptions such as "first, second", "S1, S2", "step one, step two" in the embodiments of the present invention, such descriptions are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features or indicating the execution order of the method, etc. Those skilled in the art can understand that all those that do not violate the invention points under the inventive concept of the invention should be included in the protection scope of the present invention.

[0056] The present invention provides a sterilization device for low-viscosity liquid food, referring to Figure 1 , including: a control unit 100, and a microwave heating unit 200, a high-voltage pulsed electric field unit 300, and a cooling unit 400 connected to the control unit 100;

[0057] The microwave heating unit 200, the high-voltage pulsed electric field unit 300, and the cooling unit 400 are connected in sequence from beginning to end, and under the control of the control unit 100, sequentially perform microwave rapid heating sterilization, high-voltage pulsed electric field sterilization, and low-temperature cooling on the low-viscosity liquid food respectively.

[0058] In this embodiment, a sterilization device for low-viscosity liquid food is provided. When in use, first, the low-viscosity liquid food is introduced into the microwave heating unit. Microwave heating can, within a short period of time, raise the temperature of the low-viscosity liquid food to the temperature required for sterilization, sterilize the low-viscosity liquid food, effectively kill most microorganisms, and at the same time maintain the flavor and nutritional components of the food. Then, the low-viscosity liquid food is introduced into the high-voltage pulsed electric field unit. The high-voltage pulsed electric field destroys the cell membranes of microorganisms, making them lose their activity, thereby further reducing the number of microorganisms in the food, ensuring food safety, and at the same time not causing an obvious thermal effect, and preferably maintaining the original quality and flavor of the food. Finally, the sterilized low-viscosity liquid food enters the cooling unit. Through rapid cooling, the food temperature is reduced, preventing the loss of flavor and nutrients caused by high temperature, and improving the storage stability of the food. At the same time, using instantaneous low temperature, some microorganisms are killed again. Moreover, due to the fact that this device utilizes the fluidity of the low-viscosity liquid food, the low-viscosity liquid food can be continuously processed, greatly improving the production efficiency. It should be noted that for the low-viscosity liquid food cooled by the cooling unit, the operator can directly export and store it according to actual needs, or can reintroduce the processed low-viscosity food into the microwave heating unit for multiple cycle processing. In addition, the sterilization device for low-viscosity liquid food provided by the present invention can also be used for sterilization of other liquid foods with fluidity or liquid materials with fluidity.

[0059] Exemplarily, to compare the differences between the present invention and traditional pasteurization, existing microwave radiation sterilization, and a single pulsed electric field sterilization device, the low-viscosity liquid food sterilization device of the present invention is used for the sterilization of fresh milk as an example. First, put fresh milk into the microwave heating unit and heat it for 18 s. The outlet temperature of the fresh milk in the microwave heating unit reaches 75 °C. Then, the fresh milk flows into the high-voltage pulsed electric field unit, and the electric field strength is controlled at 40 kV / cm, the treatment time is 50 s, and the number of pulses is 10. Finally, the fresh milk is cooled in the cooling unit for 20 s, so that the temperature of the low fresh milk at the outlet of the cooling unit is 3 °C, and then the treated fresh milk is exported to obtain Experimental Group 1. Using traditional pasteurization, the fresh milk is treated at 75 °C for 20 s and then rapidly cooled to 4 °C to obtain Product 1. Using existing microwave radiation sterilization, the fresh milk is treated in a microwave generator at 500 W for 30 s and then rapidly cooled to 4 °C to obtain Product 2. Using a single high-voltage pulsed electric field sterilization, the fresh milk is treated under the conditions of an electric field strength of 70 kV / cm, a pulse number of 10, and a material temperature of 70 °C for 70 s and then rapidly cooled to 4 °C to obtain Product 3. Comparing Experimental Group 1, Product 1, Product 2, and Product 3, referring to Table 1, when using the low-viscosity liquid food sterilization device provided by the present invention and the low-viscosity liquid food sterilization method described below, compared with existing pasteurization, microwave radiation sterilization, and a single pulsed electric field sterilization, in terms of functional nutrition: the degree of protein denaturation, the degree of immunoglobulin loss, the degree of lactoferrin loss, and the degree of vitamin C content loss are all significantly reduced; in terms of microbial treatment: the total number of bacteria, Escherichia coli, heat-resistant spores, and lactic acid bacteria are not detected; in terms of flavor, the color is bright, the aroma is rich and pure, and the taste is rich and mellow; in terms of storage, the shelf life is significantly extended; and there is a significant improvement in production efficiency.

[0060] Table 1: Comparison table of the sterilization effects of different sterilization devices on fresh milk

[0061]

[0062]

[0063] The low-viscosity liquid food sterilization device provided by the present invention particularly utilizes the rapid heating of the microwave heating unit, the rapid discharge of the high-voltage pulsed electric field unit, and the rapid cooling of the cooling unit. Under the drastic environmental changes, it can more effectively kill microorganisms and ensure the food flavor. In summary, the present invention provides a low-viscosity liquid food sterilization device that can retain the functional nutrition of low-viscosity liquid food, preserve the flavor of low-viscosity liquid food, and can thoroughly sterilize, improve the storage period and production efficiency.

[0064] Preferably, referring to Figure 1 and Figure 2, the microwave heating unit 200 includes: a tunnel-type microwave cavity 15, a spiral glass tube 16, and a microwave generator 17;

[0065] The spiral glass tube 16 is disposed inside the tunnel-type microwave cavity 15;

[0066] The microwave generator 17 is disposed on the tunnel-type microwave cavity 15 and is directly opposite to the spiral glass tube 16.

[0067] In this embodiment, the microwave generator is directly aligned with the spiral glass tube, so that the microwave energy acts on the low-viscosity liquid food therein, greatly reducing energy loss. By using a spiral glass tube, compared with a straight heating pipe, it can provide a longer heating path and a more compact layout, realizing continuous heating of low-viscosity liquid food, and is suitable for industrial and large-scale applications. By using the microwave generator to heat with microwaves, rapid heating and cooling of low-viscosity liquid food can be achieved, further improving the controllability of the heating process.

[0068] Preferably, referring to Figure 1 and Figure 3 , the high-voltage pulsed electric field unit 300 includes: a plurality of parallel high-voltage pulsed electric field pipes 18. Through the high-voltage pulsed electric field pipes, the sterilization treatment of low-viscosity liquid food is completed by using high-voltage pulses.

[0069] More preferably, referring to Figure 1 and Figure 3 , the high-voltage pulsed electric field pipe 18 includes: a high-voltage electric field pulse generator 18a, a plate 18b, and a first liquid flow pipe 18c;

[0070] The plate 18b is disposed on both sides of the first liquid flow pipe 18c and is connected to both poles of the high-voltage electric field pulse generator 18a respectively.

[0071] In this embodiment, the high-voltage electric field pulse generator is used to generate high-voltage pulses and transmit them to the plates disposed on both sides of the first liquid flow pipe, so that the low-viscosity liquid food in the first liquid flow pipe is always uniformly under the action of the high-voltage pulsed electric field, ensuring the consistency, continuity, and stability of the sterilization effect. Due to the action of the high-voltage pulsed electric field, mainly through the electroporation effect, the microbial cell membrane is destroyed, and the liquid temperature will not be significantly increased, avoiding the loss of nutrients and flavors caused by traditional heat treatment methods. The first liquid flow pipe supports the continuous flow of low-viscosity liquid food, reduces the time interval of material handling, and improves the overall production capacity.

[0072] Preferably, referring to Figure 4 and Figure 7 , the high-voltage electric field pulse generator 18a includes: a power supply 101, a voltage transformation switch, and a transformer 4 connected to the plates in sequence;

[0073] A variable voltage switch for controlling the opening and closing of the power supply 101;

[0074] A transformer 4, comprising: a core assembly 5, a primary coil winding 6, a secondary coil winding 2, and a base 7;

[0075] The core assembly 5 is provided with a first cylindrical core 21 on the upper side, a second cylindrical core 50 on the lower side, and the left and right ends are embedded in the base 7;

[0076] The primary coil winding 6 is arranged on the second cylindrical core 50;

[0077] The secondary coil winding 2 is arranged on the first cylindrical core 21.

[0078] In this embodiment, the transformer performs a preliminary boost on the power supply to ensure that sufficient high-voltage pulses can be provided, enabling the electrode plates to form a strong electric field and improving the electric field treatment effect. The variable voltage switch is used to control the opening and closing of the power supply to improve the voltage controllability of the electric field pulse generator. Optionally, the variable voltage switch is an element with a switching function such as a knife switch or a safety switch. The left and right ends of the core assembly are embedded in the base, improving the structural stability of the transformer. The primary coil winding is arranged on the second cylindrical core, while the secondary coil winding is arranged on the first cylindrical core, making the output of high-voltage pulses more stable and ensuring the continuous working reliability of the high-voltage electric field pulse generator. Through the structure of the first cylindrical core and the second cylindrical core of the core assembly, efficient magnetic flux guiding is achieved, reducing magnetic flux leakage and improving the electromagnetic coupling efficiency. More preferably, referring to Figure 4 , the high-voltage electric field pulse generator 18a further includes: an inverter controller 102 arranged at the rear end of the power supply 101; to be applicable to the scenario where the power supply is a DC power supply.

[0079] More preferably, referring to Figure 7 and Figure 8 , the core assembly 5 includes: two symmetrically arranged cores; both ends of the cores have columnar protrusions; the columnar protrusions 51 at the first end are connected to form the first cylindrical core 21; the columnar protrusions 52 at the second end are connected to form the second cylindrical core 50. To reduce the processing difficulty and installation difficulty of the core assembly, and reduce the deployment difficulty and processing cost of the low-viscosity liquid food sterilization device.

[0080] More preferably, referring to Figure 5 , the first cylindrical core 21 includes: a winding winding space 22 and an electrical isolation interval space 23 divided by multiple layers of plates;

[0081] For the winding winding space 22 and the electrical isolation interval space 23, lead-out slots 26 are provided on adjacent plates, and two adjacent lead-out slots 26 are arranged radially staggered;

[0082] The enameled wire of the secondary coil winding 2 has one end connected at the terminal 24 beside the first winding winding space 22. After winding in the first winding winding space 22, it passes through the winding-out notch 26, enters the next winding winding space 22 for winding, and finally winds out from the terminal 24 beside the last winding winding space.

[0083] In this embodiment, the first cylindrical core is divided by a multi-layer plate body to form a winding winding space and an electrical isolation interval space. The winding winding space is used to accommodate the secondary coil winding, while the electrical isolation interval space provides insulation to avoid electrical interference between windings, effectively improving the insulation performance between windings, reducing the risk of inter-turn voltage breakdown, and enabling the device to provide a stronger high-voltage electric field pulse. The enameled wire of the secondary coil winding is connected from the terminal, wound in the first winding winding space, and then enters the next winding winding space through the winding-out notch, and is sequentially transmitted downward according to the winding-out notches arranged in a staggered manner on adjacent plate bodies, and finally winds out from the terminal of the last winding winding space. This ensures that the windings are wound layer by layer in an orderly manner along a predetermined path and can maintain insulation and mechanical stability between the windings.

[0084] Preferably, referring to Figure 6 and Figure 9 , within the enameled wire wound on the winding winding space 22, there are multiple insulating rings 27 for spacing;

[0085] Insulating resin is poured into the winding winding space 22 and the electrical isolation interval space 23, and a vacuum machine is used to exhaust the gas in the resin.

[0086] In this embodiment, the setting of the insulating rings effectively enhances the inter-layer insulation ability, prevents arc breakdown between high-voltage windings, prolongs the service life of the windings, and can also ensure that the high-voltage pulse electric field unit provides a higher electric field pulse. The insulating resin, on the one hand, is an insulating heat-conducting medium, which helps to evenly conduct the heat generated during the operation of the windings to the outside, reduce local overheating, and improve the electrical stability of the equipment; on the other hand, after pouring the insulating resin, the entire winding structure will become stronger, which can effectively prevent vibrations and external mechanical stresses from damaging the windings and improve the structural reliability of the equipment. More preferably, when pouring the insulating resin, a vacuum machine is used to exhaust the gas in the resin to eliminate the bubbles in the resin, avoid partial discharge caused by air gaps, and improve the electrical insulation performance. More preferably, referring to Figure 10 , a resin casting bonding plate 8 is arranged outside the secondary coil winding 2 to further improve the insulation of the device.

[0087] More preferably, referring to Figure 9, the insulating coil 27 includes: two symmetric insulating arc coils; one of the insulating arc coils is provided with a perforation 271 to facilitate the winding, installation, disassembly and recycling of the enameled wire.

[0088] Preferably, the high-voltage electric field pulse generator 18a further includes: a voltage multiplier module 3 provided at the rear end of the transformer 4;

[0089] The voltage multiplier module 3, refer to Figure 3 , Figure 4 and Figure 11 , includes: a capacitor voltage multiplier circuit 34, a first-side voltage output terminal 33 provided, and a first input terminal 31 and a second input terminal 32 provided on the second side;

[0090] The voltage output terminal 33 is connected to the plate 18c;

[0091] The first input terminal 31 and the second input terminal 32 are connected to both ends of the transformer 4.

[0092] In this embodiment, the voltage multiplier module can, through the capacitor voltage multiplier circuit, rectify and double the alternating voltage after receiving the alternating voltage from both ends of the transformer at the input end, boost the lower alternating voltage to a higher direct current voltage, and output it to the plate through the voltage output terminal. The effect of obtaining a high-voltage output is achieved without increasing the size or the number of turns of the transformer winding, effectively improving the output voltage level of the power supply, simplifying the overall circuit structure, and reducing the manufacturing cost.

[0093] More preferably, refer to Figure 11 and Figure 12 , the capacitor voltage multiplier circuit 34 includes: a first rectifying circuit 34a and a second rectifying circuit 34b;

[0094] The first rectifying circuit 34a adopts a multi-stage voltage multiplier rectifying circuit combined with a diode and a capacitor to boost-rectify the alternating current provided by the power supply;

[0095] The second rectifying circuit 34b adopts a bridge rectifying circuit to rectify the alternating current provided by the alternating power supply;

[0096] The first rectifying circuit 34a and the second rectifying circuit 34b are switchably connected to the plate 18c.

[0097] In this embodiment, for the aforementioned power input transformer, through turns ratio transformation, the transformer raises the voltage to the required high-voltage alternating current. Then, it is input into the first rectification circuit or the second rectification circuit to obtain the secondarily boosted direct current to cooperate with the electrode plates to complete the output of the high-voltage electric field. The first rectification circuit and the second rectification circuit can be switched with each other to increase the boost adjustment range of the high-voltage electric field pulse generator. By selecting high-voltage multiple DC output or low-voltage DC output, it can adapt to different electric field intensity requirements.

[0098] Preferably, the cooling unit includes: a plate-frame cooler, a cooling pipeline arranged on the plate-frame cooler, and a second liquid flow pipeline arranged inside the plate-frame cooler;

[0099] One end of the second liquid flow pipeline is connected to the first liquid flow pipeline, and the other end is provided with a discharge port.

[0100] In this embodiment, for the cooling pipeline arranged on the plate-frame cooler, through the circulation of the coolant in the cooling pipeline and in combination with the large-area plate heat exchange structure of the plate-frame cooler, it realizes the rapid cooling of the low-viscosity liquid food in the second liquid flow pipeline. By utilizing this drastic change in temperature, it further kills microorganisms and retains the flavor of the food.

[0101] Preferably, the control unit includes: a monitoring and data acquisition module, a central control module, a motion module, and a human-machine interface that are interconnected;

[0102] The monitoring and data acquisition module collects and monitors the temperature of the material in the microwave heating unit, the temperature of the material in the cooling unit, and the voltage of the high-voltage electric field pulse unit. At the same time, it collects and monitors the material flow rates of the microwave heating unit, the high-voltage pulsed electric field unit, and the cooling unit;

[0103] The motion module is used to adjust the material flow rate and the open / close state of the materials in the microwave heating unit, the high-voltage electric field pulse unit, and the cooling unit;

[0104] The central control module uses the data collected by the monitoring and data acquisition module and combines the instructions input through the human-machine interface to adjust the output power and the material flow rate of the microwave heating unit, the high-voltage electric field pulse unit, and the cooling unit;

[0105] The human-machine interface is used to input control instructions and display the data and working status collected by the monitoring and data acquisition module, the motion module, and the central control module.

[0106] In this embodiment, the monitoring and data acquisition module continuously and real-time monitors the key operating parameters of the microwave heating, high-voltage electric field pulse, and cooling unit, including temperature, voltage, material flow rate, etc. The central control module makes dynamic adjustments according to the collected data and the instructions input through the human-machine interface to ensure that the processing time, power, and flow rate of the material in different processing units are automatically optimized, improving the overall processing efficiency and automation efficiency.

[0107] Specifically, referring to Figure 1 , the motion module includes: a first water pump 9, a second water pump 10, a third water pump 11, a first valve 12, and a third valve 14;

[0108] The first water pump 9 is arranged at the front end of the microwave heating unit 200;

[0109] The second water pump 10 is arranged at the front end of the high-voltage pulsed electric field unit 300;

[0110] The third water pump 11 is arranged at the front end of the cooling unit 400;

[0111] The first valve 12 is arranged between the cooling unit 400 and the microwave heating unit 400;

[0112] The third valve 14 is arranged at the discharge port position of the cooling unit 400.

[0113] In this embodiment, the central control module adjusts the output power of the first water pump, the second water pump, and the third water pump of the motion module to regulate the flow rate of the low-viscosity liquid food in the device, and combines the control of the opening and closing states of the first valve and the third valve to achieve accurate matching of the flow rate requirements in the microwave heating, pulsed electric field, and cooling processes, while optimizing energy consumption and improving the material processing efficiency.

[0114] More preferably, referring to Figure 1 , the motion module further includes: a second valve 13 connected to the central control module;

[0115] The first valve 12 is arranged at one end close to the cooling unit 400;

[0116] The second valve 13 is arranged at one end far from the cooling unit 400.

[0117] In this embodiment, a second valve is added to the motion module. When the central control module controls the second valve to close and the third valve to open, the export of the low-viscosity liquid food material is realized; when the central control module controls the first valve to open and the third valve to close, the cyclic processing of the low-viscosity liquid food material is realized. Avoid the stagnation of the low-viscosity liquid food in the connection channel between the first valve and the second valve.

[0118] A sterilization method for low-viscosity liquid food, using any one of the above-mentioned low-viscosity liquid food sterilization devices, the steps include: First, the monitoring and data acquisition module of the control unit performs data acquisition, simulation and emulation;

[0119] Next, the distributed control module and the central control module control the microwave heating unit, the high-voltage pulsed electric field unit and the cooling unit through the input logic operation instructions and timer / counter instructions;

[0120] Then, introduce the low-viscosity liquid food into the microwave heating unit; the microwave heating unit adjusts the microwave generation power, the flow rate of the low-viscosity liquid food and the temperature of the low-viscosity liquid food to preset values;

[0121] Then, adjust the ambient temperature of the high-voltage pulsed electric field unit to be consistent with the temperature of the liquid food flowing at the feed inlet, and adopt different preset electric field intensities according to the type of low-viscosity liquid food;

[0122] Finally, introduce the low-viscosity liquid food into the cooling unit, and after cooling, select to repeat the above sterilization process or perform aseptic filling according to the sterilization effect.

[0123] In this embodiment, a sterilization method for low-viscosity liquid food is provided, which uses microwave heating, high-voltage pulsed electric field and rapid cooling for synergistic sterilization, and uses the sharp change of the environment to improve the killing rate of microorganisms. It solves the disadvantages that in traditional sterilization methods, it is impossible to take into account the preservation of nutrition, flavor, effective killing of spoilage and pathogenic microorganisms, and also solves the defects of incomplete non-thermal sterilization and difficulty in industrial application of new non-thermal sterilization.

[0124] Exemplarily, to compare the differences between the present invention and traditional pasteurization, existing microwave radiation sterilization, and single pulsed electric field sterilization methods, the low-viscosity liquid food sterilization method of the present invention is used for apple juice sterilization as an example. First, the apple juice is put into the microwave heating unit and heated for 25 s, and the outlet temperature of the apple juice in the microwave heating unit reaches 75 °C; then, the apple juice flows into the high-voltage pulsed electric field unit, and the electric field strength is controlled at 50 kV / cm, the treatment time is 50 s, and the number of pulses is 10; finally, the apple juice is cooled in the cooling unit for 25 s, so that the temperature of the low-viscosity liquid food at the outlet of the cooling unit is 4 °C, and then the treated apple juice is exported to obtain Experimental Group 2. For traditional pasteurization, the apple juice is treated at 75 °C for 20 s and then rapidly cooled to 4 °C to obtain Product 4; for existing microwave radiation sterilization, the apple juice is treated in a microwave generator at 500 W for 30 s and then rapidly cooled to 4 °C to obtain Product 5; for single high-voltage pulsed electric field sterilization, the apple juice is treated under the conditions of an electric field strength of 70 kV / cm, a pulse number of 10, and a material temperature of 70 °C for 70 s and then rapidly cooled to 4 °C to obtain Product 6. Comparing Experimental Group 2, Product 4, Product 5, and Product 6, referring to Table 1, when using the low-viscosity liquid food sterilization method, compared with the existing pasteurization, microwave radiation sterilization, and single pulsed electric field sterilization methods, in terms of functional nutrition: the degree of protein denaturation, the content of vitamin C, and the loss degree of vitamin B6 are all significantly reduced, while the polyphenol content is significantly increased; in terms of microbial treatment: the total number of bacteria, Escherichia coli, yeast, and mold are not detected; in terms of flavor, the color is bright yellow, fresh and fragrant, and pure; in terms of storage, the shelf life is significantly extended, and the inactivation degree of lipoxygenase is significantly increased; there is a significant improvement in production efficiency.

[0125] Table 2: Comparison Table of the Sterilization Effects of Different Sterilization Methods on Apple Juice

[0126]

[0127]

[0128] In summary, the low-viscosity liquid food sterilization method provided by the present invention has great advantages in terms of flavor retention, sterilization effect, shelf life, and production efficiency compared with traditional pasteurization, single microwave radiation, and pulsed electric field sterilization methods.

[0129] More preferably, the power of the microwave heating unit is controlled to be 200 - 500 w. By controlling the flow rate of the liquid food in the spiral glass pipeline to be 0.085 - 0.25 m / s, after the material liquid undergoes microwave treatment for 15 - 20 s, the outlet temperature of the microwave heating unit is 60 - 75 °C. In the high-voltage pulsed electric field unit, the high-voltage pulsed electric field intensity is controlled at 40 - 50 kV / cm, the treatment time is 30 - 50 s, and the number of pulses is 5 - 10. Different electric field intensities are adopted according to different material categories. First, the first rectifier circuit of the transformer is used for pulsed electric field sterilization and the treatment time is controlled. Then, the second rectifier circuit is used for pulsed electric field sterilization and the treatment time is controlled. The outlet temperature of the cooling unit is maintained between 3 - 4 °C. By precisely controlling the key parameters of microwave heating, high-voltage pulsed electric field, and the cooling unit, it is ensured that the low-viscosity liquid food achieves efficient sterilization, quality retention, and energy consumption optimization during the sterilization process.

[0130] The above-mentioned low-viscosity liquid food sterilization method is created based on the above-mentioned low-viscosity liquid food sterilization device. The combination of its technical effects and technical features will not be elaborated here. The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A low-viscosity liquid food sterilization device, characterized in that, Including: a control unit, and a microwave heating unit, a high-voltage pulsed electric field unit, and a cooling unit connected to the control unit; The microwave heating unit, the high-voltage pulsed electric field unit, and the cooling unit are connected in sequence from beginning to end, and under the control of the control unit, they respectively perform on low-viscosity liquid food in sequence: rapid microwave heating and sterilization, high-voltage pulsed electric field sterilization, and low-temperature cooling.

2. The low-viscosity liquid food sterilization device according to claim 1, characterized in that, The microwave heating unit includes: a tunnel-type microwave cavity, a spiral glass tube, and a microwave generator; The spiral glass tube is arranged inside the tunnel-type microwave cavity; The microwave generator is arranged on the tunnel-type microwave cavity and is facing the spiral glass tube.

3. The low-viscosity liquid food sterilization device according to claim 2, wherein, The high-voltage pulsed electric field unit includes: multiple parallel high-voltage pulsed electric field pipes; The high-voltage pulsed electric field pipe includes: a high-voltage electric field pulse generator, electrode plates, and a first liquid flow pipe arranged at intervals; The electrode plates are arranged on both sides of the first liquid flow pipe and are connected to the two poles of the high-voltage electric field pulse generator respectively.

4. The low-viscosity liquid food sterilization device according to claim 3, characterized in that, The high-voltage electric field pulse generator includes: a power supply, a voltage transformation switch, and a transformer connected to the electrode plates connected in sequence; The voltage transformation switch is used to control the opening and closing of the power supply; The transformer includes: an iron core assembly, a primary coil winding, a secondary coil winding, and a base; The iron core assembly is provided with a first cylindrical core on the upper side, a second cylindrical core on the lower side, and the left and right ends are embedded in the base; The primary coil winding is arranged on the second cylindrical core; The secondary coil winding is arranged on the first cylindrical core.

5. The low-viscosity liquid food sterilization device according to claim 4, wherein, The first cylindrical core includes: a winding winding space and an electrical isolation interval space divided by multiple layers of plate bodies; For the winding winding space and the electrical isolation interval space, the adjacent plate bodies are provided with winding outlets, and the adjacent two winding outlets are arranged radially staggered; One end of the insulating enameled wire of the secondary coil winding is connected from the terminal beside the first winding winding space, after winding in the first winding winding space, it enters the next winding winding space through the winding outlet and winds, and finally winds out from the terminal beside the last winding winding space.

6. The low-viscosity liquid food sterilization device according to claim 5, characterized in that, Inside the insulating enameled wire wound on the winding winding space, there are multiple layers of insulating rings arranged at intervals; Insulating resin is poured into the winding winding space and the electrical isolation interval space.

7. The low-viscosity liquid food sterilization device according to claim 6, characterized in that, The high-voltage electric field pulse generator further includes: a voltage multiplier module arranged at the rear end of the transformer; The voltage multiplier module includes: a capacitor voltage multiplier circuit, a first side voltage output terminal, and a first input terminal and a second input terminal arranged on the second side; The voltage output terminal is connected to the electrode plate; The first input terminal and the second input terminal are connected to both ends of the transformer.

8. The low-viscosity liquid food sterilization device according to claim 7, characterized in that, The cooling unit includes: a plate-frame cooler, a cooling pipe arranged on the plate-frame cooler, and a second liquid flow pipe arranged inside the plate-frame cooler; One end of the second liquid flow pipe is connected to the first liquid flow pipe, and the other end is provided with a discharge port.

9. The low-viscosity liquid food sterilization device according to claim 8, characterized in that, The control unit includes: a monitoring and data acquisition module, a central control module, a motion module, and a human-machine interface connected to each other; The monitoring and data acquisition module collects and monitors the material temperature in the microwave heating unit, the material temperature in the cooling unit, the voltage of the high-voltage electric field pulse unit, and at the same time collects and monitors the material flow rates of the microwave heating unit, the high-voltage pulsed electric field unit, and the cooling unit; A motion module, which is used to adjust the material flow rate and the opening and closing state of the material of the microwave heating unit, the high-voltage electric field pulse unit and the cooling unit; A central control module, which uses the data collected by the monitoring and data acquisition module, combines the instructions input by the human-machine interaction interface, and adjusts the output power and the material flow rate of the microwave heating unit, the high-voltage electric field pulse unit and the cooling unit; A human-machine interaction interface, which is used to input control instructions and display the data and working status collected by the monitoring and data acquisition module, the motion module and the central control module.

10. A method for sterilizing a low-viscosity liquid food, characterized in that, When using the low-viscosity liquid food sterilization device described in any one of claims 1-9, the steps include: First, the monitoring and data acquisition module of the control unit performs data acquisition, simulation and emulation; Next, the distributed control module and the central control module control the microwave heating unit, the high-voltage pulse electric field unit and the cooling unit through the input logic operation instructions and timer / counter instructions; Next, the low-viscosity liquid food is introduced into the microwave heating unit; the microwave heating unit adjusts the microwave generation power, the low-viscosity liquid food flow rate and the low-viscosity liquid food temperature to preset values; Then, the ambient temperature of the high-voltage pulse electric field unit is adjusted to be consistent with the temperature of the liquid food flowing at the feed port, and different preset electric field intensities are adopted according to the type of the low-viscosity liquid food; Finally, the low-viscosity liquid food is introduced into the cooling unit, and after cooling, the above sterilization process is selected to be repeated or aseptic filling is performed according to the sterilization effect.

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