Nanosecond pulse plasma pipeline type grain conveying and sterilizing integrated device

Abstract

The invention relates to the technical field of grain conveying, disinfecting and killing, in particular to a nanosecond pulse plasma pipeline type grain conveying, disinfecting and killing integrated device. Comprising a nanosecond pulse power supply, a high-voltage electrode, a dielectric layer, a grounding metal shell, a driving motor, a spiral blade, a feed port and a discharge port, the dielectric layer and the grounding metal shell are nested to form a cylindrical processing channel, and the high-voltage electrode is coaxially arranged in the center of the cylindrical processing channel; a feeding hole is formed in one end of the cylindrical treatment channel; a discharge hole is formed in the other end; the spiral blade is connected with the driving motor, a temperature and humidity sensor and an ozone sensor are arranged on the inner wall of the metal shell, and the nanosecond pulse power supply dynamically adjusts output parameters according to feedback of the temperature and humidity sensor and the ozone sensor. Grain conveying and green sterilization are synchronously completed, and the device has the remarkable advantages of being high in treatment efficiency, low in energy consumption, free of chemical residues and the like.

Description

Technical Field

[0001] This invention relates to the field of grain transport and disinfection technology, specifically to a nanosecond pulse plasma pipeline-type integrated grain transport and disinfection device. Background Technology

[0002] During grain storage, pathogenic microorganisms such as Aspergillus flavus and Fusarium can easily proliferate. These microorganisms not only cause grain to mold and spoil, but also produce highly carcinogenic toxins, seriously threatening food safety and human health. Traditional disinfection technologies face multiple limitations: thermal sterilization inevitably leads to protein denaturation and significant vitamin loss during high-temperature treatment, significantly reducing grain quality; ultraviolet irradiation technology has limited penetration into stacked grains, and the sterilization effect in shaded areas decreases sharply; chemical fumigation carries the risk of toxic residues, and its long processing cycle is difficult to match the operational pace of modern grain depots.

[0003] In recent years, low-temperature plasma technology has been regarded as a novel solution for grain sterilization. Among them, plasma driven by nanosecond pulse power supplies has attracted much attention due to its uniform discharge and low gas temperature. Its advantages are mainly reflected in the extremely high peak power and extremely fast rise time (nanosecond level) of nanosecond pulses. This instantaneous high-power injection can generate an extremely strong electric field in the gas gap, efficiently coupling energy to electrons rather than heavy particles (ions, neutral molecules). This allows electrons to be accelerated to very high energies in a very short time, far exceeding the ionization energy and chemical bond energy of gas molecules, thereby efficiently ionizing and dissociating gas molecules (such as O2, N2, H2O), producing a large number of highly active and highly bactericidal substances (such as O, OH, O3, excited-state N2, UV photons, etc.). Due to the extremely short pulse duration (nanosecond level), the energy is mainly deposited on electrons. The timescale for electrons to collide with heavy particles (ions, neutral molecules) and transfer energy is much longer than the pulse width. Therefore, during the interval between two pulses, the electron energy has sufficient time to be consumed through inelastic collisions (excitation, ionization), rather than being converted into the disordered thermal motion of gas molecules. This allows the overall temperature of the discharge gas to be maintained close to room temperature, fundamentally avoiding protein denaturation and vitamin loss caused by thermal sterilization, perfectly meeting the processing needs of heat-sensitive materials such as grains. The extremely short pulse width limits the accumulation of space charge in the discharge channel, which helps to suppress the transformation of the discharge from uniform discharge to energy-concentrated, highly destructive filamentary arc discharge. This makes it easier for nanosecond pulse discharge to form a relatively uniform and diffuse plasma region in a larger space, which is beneficial for processing grains with irregular surfaces and a certain thickness of accumulation. The high-energy electrons and short-wavelength ultraviolet light generated have better penetrability than the active substances generated by long pulses or AC discharges, providing a physical basis for solving the problem of grain stacking shadows. By precisely adjusting the parameters of the nanosecond pulse (such as pulse voltage, width, repetition frequency, rise / fall edge), the distribution of electron energy and the type / concentration of active particles in the plasma can be finely controlled. For example, optimizing parameters can effectively control the generation of ozone (O3) while ensuring sterilization effectiveness (dependent on high-energy electrons, O, OH, etc.), reducing its potential negative impact on grain quality (such as lipid oxidation and vitamin destruction) and the pressure on subsequent exhaust gas treatment. This ability to "customize" active species on demand is difficult to achieve with traditional continuous wave or long pulse power supplies. This provides a key technical basis for adapting to the dynamically changing environment during grain transportation (such as fluctuations in grain flow rate and changes in humidity / temperature), maintaining the equipment's optimal sterilization state and operational stability through real-time feedback control.

[0004] Existing equipment mostly employs a static processing mode, making it difficult to integrate effectively with continuous grain conveying systems, and its processing efficiency is insufficient to meet the needs of large-scale grain depots. More importantly, dynamic environmental changes during grain processing lead to decreased stability of plasma generators, such as the susceptibility to abnormal discharge accidents under high humidity conditions and the impact on grain quality under high temperature and high ozone concentrations. Such equipment often lacks the ability to monitor key process parameters (such as real-time changes in temperature, humidity, ozone concentration, and grain flow rate within the processing chamber) online, and cannot dynamically control the discharge process based on this real-time data. The direct consequence is that sterilization efficiency fluctuates drastically under complex operating conditions, reducing equipment reliability, increasing the risk of failure, and making it difficult to operate stably and safely for extended periods in actual continuous, high-throughput grain depot conveying systems.

[0005] Therefore, the industry urgently needs a grain disinfection technology that can truly achieve continuous operation, strong dynamic adaptability, and safe and controllable operation. This technology not only needs to ensure efficient sterilization and maximize grain quality preservation, but more importantly, it must be seamlessly integrated into the raw grain conveying system, enabling simultaneous disinfection during grain transport and flow, thus completely eliminating efficiency bottlenecks. This means that the core equipment must be able to intelligently sense and quickly respond to constantly changing operating conditions within the conveying pipeline—including fluctuations in grain flow rate, changes in ambient temperature and humidity, changes in dust concentration, and the accumulation level of active substances such as ozone. Only by collecting these key parameters in real time and utilizing the unique rapid response and high-precision controllability of nanosecond pulse power supplies to dynamically adjust their discharge parameters (such as pulse voltage, frequency, and pulse width) can stable and uniform discharge be maintained in high-humidity environments, avoiding abnormal arcs; ozone generation be actively suppressed when the ozone concentration approaches the threshold to prevent grain quality deterioration; and energy injection be optimized in real time when grain flow rate changes to ensure a consistent and efficient sterilization dose at different flow rates. By deeply integrating the high-efficiency, low-temperature sterilization advantages of nanosecond pulsed plasma with a pipeline-type continuous processing structure and an intelligent closed-loop control system based on multi-sensor feedback, an integrated transmission and disinfection equipment can be constructed. This is the only way to fundamentally overcome the limitations of existing technologies and meet the needs of large-scale, continuous, and intelligent operations in modern grain depots. Summary of the Invention

[0006] This invention addresses the problems of low processing efficiency, inability to guarantee the nutritional quality of grain, complex structure, high cost, poor equipment stability and adaptability to operating conditions, and complicated operation of existing plasma grain sterilization devices. It proposes a nanosecond pulse plasma pipeline-type integrated grain transport and sterilization device, comprising: a nanosecond pulse power supply, a high-voltage electrode, a dielectric layer, a grounded metal shell, a drive motor, spiral blades, an inlet, and an outlet. The dielectric layer and the grounded metal shell are nested to form a cylindrical processing channel, with the high-voltage electrode coaxially positioned at the center of the cylindrical processing channel. An inlet is located at one end of the cylindrical processing channel, and an outlet is located at the other end. The spiral blades are connected to the drive motor. Temperature and humidity sensors and an ozone sensor are installed on the inner wall of the metal shell. The nanosecond pulse power supply dynamically adjusts its output parameters based on feedback from the temperature and humidity sensors and the ozone sensor. The spiral blades are continuous spiral ribbon structures with equal pitch and thickness, and the helix angle is 15°-20°; the spiral blades coaxially surround the high-voltage electrode, and an annular gap channel is formed between them.

[0007] According to the nanosecond pulse plasma pipeline grain conveying and sterilization integrated device described above, the high voltage pulse amplitude output by the nanosecond pulse power supply is continuously adjustable from 20 to 60 kV, and the pulse rise time is <100 ns.

[0008] According to the nanosecond pulse plasma pipeline grain conveying and sterilization integrated device described above, the high-voltage electrode is a surface-polished stainless steel metal rod, and the minimum gap between it and the inner edge of the spiral blade is >1cm.

[0009] According to the nanosecond pulse plasma pipeline grain conveying and sterilization integrated device described above, the material of the medium layer is polytetrafluoroethylene, and the thickness is 0.2-0.5cm.

[0010] According to the nanosecond pulse plasma pipeline grain conveying and sterilization integrated device described above, the spiral blade is made of polytetrafluoroethylene composite material, with an outer diameter of 5-8cm and an axial length of 50-80cm.

[0011] According to the nanosecond pulse plasma pipeline grain conveying and sterilization integrated device described above, the grounded metal shell is made of 304 stainless steel with a thickness of 0.1-0.4cm.

[0012] According to the nanosecond pulse plasma pipeline grain conveying and disinfection integrated device described above, the sensing end faces of the temperature and humidity sensor and the ozone sensor are conformally flush with the inner wall of the metal shell, and their protrusion height is <0.1mm.

[0013] According to the nanosecond pulse plasma pipeline grain conveying and sterilization integrated device described above, the drive motor is a variable frequency speed control motor, which is connected to the spiral blades through a coupling.

[0014] The nanosecond pulse plasma pipeline grain conveying and disinfection integrated device described above also includes a control unit connected to a temperature and humidity sensor and an ozone sensor, used to receive signals from the temperature and humidity sensor and ozone sensor and feed back the output parameters of the nanosecond pulse power supply.

[0015] According to the nanosecond pulse plasma pipeline grain conveying and sterilization integrated device described above, the device realizes the synchronous operation of grain conveying and plasma sterilization. The cylindrical processing channel has a length of 60-80cm and an outer diameter of 5-10cm.

[0016] The beneficial effects of this invention are as follows: 1. Significantly Improved Grain Disinfection and Processing Efficiency. Traditional plasma disinfection equipment is mostly a closed-chamber structure, requiring a batch processing mode, i.e., "loading-static treatment-unloading," which involves a significant amount of auxiliary time, resulting in low efficiency and making it unsuitable for integration into continuously operating grain depot conveyor lines. This invention integrates a shaftless screw conveyor and a plasma generator into the same pipeline: a channel formed by a medium layer and a grounded metal shell. The uniform rotation of the screw blades allows grain particles to continuously pass through the plasma treatment zone at a stable flow rate, achieving continuous operation of "simultaneous conveying and processing." Simultaneously, the screw blades adopt a continuous helical strip structure with equal pitch and thickness, optimizing the pitch, blade height, gap and roughness between the blade outer edge and the inner wall of the metal shell, and the helix angle. The rationality of the structural design and the uniformity of material flow are verified through fluid dynamics (CFD) simulation experiments. The simulation model is built to a 1:1 scale based on the actual equipment size. It employs the Discrete Element Method (DEM) coupled with gas flow simulation to analyze the trajectory, velocity distribution, and shear force state of grain particles during the spiral propulsion process. This ensures that the grain particles in the device are subjected to uniform shear force during transport, flowing in a thin, dispersed state, avoiding local accumulation or stagnation. On one hand, this creates a stable and uniform material distribution, providing an unobstructed path for the plasma and significantly improving the contact efficiency between active particles and the grain surface. On the other hand, it reduces frictional losses between particles and blades, preventing grain breakage and ensuring the continuity and stability of the transport process. Its structural design ensures uniform, thin-layer material flow, solving the "shadowing effect" and sterilization dead zones caused by grain accumulation in traditional ultraviolet or static plasma treatments. Compared to existing technologies, this device improves processing efficiency several times, truly matching the high-throughput operation rhythm of modern grain depots.

[0017] 2. Improvement of Grain Nutritional and Sensory Quality. Existing plasma sterilization equipment inevitably leads to protein denaturation, vitamin degradation, and loss of flavor substances. The core of this invention lies in the use of a dielectric barrier discharge (DBD) mechanism driven by a nanosecond pulse power supply. The extremely fast rise time and short pulse width of the nanosecond-level pulse can efficiently couple energy to electrons, forming a low-temperature non-equilibrium plasma with an electron temperature (Te>5eV) much higher than the temperature of ions and neutral particles (Ti,Tn<40℃). The dielectric layer further restricts the current and inhibits Joule heat accumulation. Therefore, thermal damage can be fundamentally avoided. Tests show that the internal temperature rise of grain ΔT is <2℃, and the thermal damage layer on the outer skin is ≤50μm, thus preserving the original nutritional value and sensory quality of the grain to the greatest extent.

[0018] 3. Significantly reduced energy consumption and operating costs, and complete elimination of chemical residues. Traditional plasma sterilization equipment is energy-intensive. This invention utilizes a nanosecond pulse discharge structure, injecting peak power only within a nanosecond, but with extremely low average power. Almost all energy is used to excite high-energy electrons to generate active particles, rather than being wasted heat. Therefore, overall energy consumption is reduced by more than 50% compared to thermal sterilization. Furthermore, the plasma is generated by the ionization of air (O2, N2, H2O). After sterilization, the active particles recombine into harmless nitrogen, oxygen, and water. No chemical agents are added throughout the process, eliminating the risk of residual toxic and harmful substances at the source, making it a truly green sterilization technology.

[0019] 4. Closed-loop control significantly enhances equipment stability and adaptability to operating conditions. A major drawback of existing technologies is the lack of responsiveness to dynamically changing operating conditions. High humidity environments can easily lead to short-circuit discharges in equipment, and excessively high ozone concentrations can damage the fat and vitamins in grains. This invention integrates temperature and humidity sensors and an ozone sensor, and constructs an intelligent closed-loop control system based on multi-signal feedback with a nanosecond pulse power supply and a drive motor. This system, with an embedded control unit at its core, collects sensor signals in real time and dynamically adjusts the output voltage, pulse repetition frequency, and spiral blade speed of the nanosecond pulse power supply through a PID algorithm, achieving precise control of the environment within the processing chamber. When the relative humidity inside the processing chamber exceeds 80%, the control unit can gradually reduce the pulse voltage from 40kV to below 25kV and the pulse repetition frequency from 500Hz to 200Hz according to a preset strategy, thereby suppressing the occurrence of abnormal arcs under high humidity conditions; simultaneously, it fine-tunes the spiral blade speed, extending the material throughput time by approximately 15%, ensuring that the sterilization dosage is not affected by the voltage reduction. For example, when the real-time ozone concentration approaches the preset upper limit, the control unit can respond within 5ms, adjusting the pulse rise edge from 100ns to 50ns and appropriately increasing the pulse repetition frequency to suppress the O3 generation pathway and prevent the destruction of grain nutrients. This dynamic control mechanism based on multi-sensor feedback enables the equipment to adapt to changes in grain type, flow rate, and ambient temperature and humidity, always maintaining the optimal and most stable sterilization state, significantly improving the equipment's reliability and service life.

[0020] 5. The modular, integrated structure enables simple integration and operation. Traditional plasma sterilization equipment typically requires separate deployment of the conveying and sterilization systems, resulting in large space requirements and complex interfaces. This invention employs a highly integrated "pipeline-style" design, integrating conveying, sterilization, and monitoring functions into a compact cylindrical unit. The spiral blades are made of insulated polytetrafluoroethylene composite material, fundamentally eliminating the risk of electrical breakdown with the high-voltage electrodes and eliminating the need for complex isolation and sealing structures. The inlet and outlet can be directly connected to the flanges of existing grain depot conveying chutes, elevators, and other equipment, offering plug-and-play functionality without requiring large-scale modifications to existing production lines. This modular design makes installation, operation, and maintenance exceptionally simple, significantly reducing integration difficulty and operation and maintenance costs for users. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the nanosecond pulse plasma pipeline grain conveying and sterilization integrated device of the present invention.

[0022] Figure 2 This is a schematic diagram of the shaftless screw feeder structure of the nanosecond pulse plasma pipeline grain conveying and sterilization integrated device of the present invention.

[0023] Figure 3This is a partial structural schematic diagram of the nanosecond pulse plasma pipeline-type integrated grain transport and sterilization device of the present invention.

[0024] In the diagram: 1-nanosecond pulse power supply, 2-high voltage electrode, 3-dielectric layer, 4-grounded metal shell, 5-temperature and humidity sensor, 6-ozone sensor, 7-drive motor, 8-spiral blade, 9-feed inlet, 10-discharge outlet. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0026] like Figures 1 to 3 As shown, the nanosecond pulse plasma pipeline grain conveying and sterilization integrated device of this embodiment includes a nanosecond pulse power supply 1, a high voltage electrode 2, a dielectric layer 3, a grounded metal shell 4, a temperature and humidity sensor 5, an ozone sensor 6, a drive motor 7, a spiral blade 8, a feed inlet 9, and a discharge outlet 10.

[0027] The dielectric layer 3 and the grounded metal shell 4 are tightly fitted and nested to form a cylindrical pipe. The top of the pipe is provided with an inlet 9 near the motor side, and the bottom is provided with an outlet 10 away from the motor side. The high-voltage electrode 2 extends coaxially through the inner cavity of the cylindrical pipe formed by the dielectric layer 3 and the grounded metal shell 4. This coaxial nesting structure makes the inner cavity form a uniformly distributed dielectric barrier discharge area along the axial direction. When the high-voltage electrode 2 applies a high-frequency AC voltage, the working gas in the inner cavity generates a large area of ​​low-temperature non-equilibrium plasma in the radial direction of the pipe under the synergistic current limiting effect of the dielectric layer 3 and the grounded metal shell 4. The physical barrier effect of the dielectric layer 3 on the discharge current effectively suppresses the generation of electric arc and spark, and avoids instantaneous high-temperature carbonization or local burning of the grain. The insulation characteristics of the dielectric layer 3 completely isolate the high-voltage electrode 2 and the grounded metal shell 4, eliminating the risk of combustion and explosion in the grain dust environment, and at the same time avoiding the pollution caused by the metal electrode directly contacting the grain. The helical blades 8 are arranged around the high-voltage electrode 2, with a constant gap of more than 1 cm between their inner edges and the outer surface of the high-voltage electrode 2. This gap size is mainly designed to suppress periodic eddies and local low-pressure areas induced by the high-speed rotating helical blades around the high-voltage electrode. When the gap is too small, the shearing effect of the rotating blade surface on the nearby airflow will be significantly enhanced, easily generating unsteady flow structures such as Karman vortex streets. These vortex structures will disturb the gas medium in the plasma region, causing the transport paths of discharge particles (electrons and ions) to deflect and diverge, thereby disrupting the spatial uniformity and temporal stability of the plasma plume. A gap of more than 1 cm provides sufficient buffer space for the airflow, allowing the airflow driven by the blade rotation to fully develop and transition smoothly, effectively weakening the direct impact of the aforementioned periodic disturbance sources on the plasma core region, and ensuring the uniformity of the active particle generation density and spatial distribution. In addition, this gap also acts as an important insulating barrier. When the nanosecond pulse power supply is working, an extremely strong transient electric field is formed between the high-voltage electrode and the grounding component. Although the helical blades are made of insulating material, their surface may adsorb grain dust or tiny conductive impurities. A safety gap of more than 1cm provides sufficient creepage distance, which can effectively prevent the high-voltage electrode from flashing or breaking down along the surface of the blade with impurities in high humidity or dusty environments, thus eliminating the risk of abnormal discharge and short circuit and ensuring the long-term reliability of the equipment.

[0028] The drive motor 7 is connected to the drive end of the spiral blade 8 via a coupling; the high voltage output end of the nanosecond pulse power supply 1 is connected to the high voltage electrode 2; the temperature and humidity sensor 5 and the ozone sensor 6 are integrated into the inner wall of the axial central area of ​​the grounded metal housing 4, with the sensing end face conformally flush with the cavity wall (protrusion height ≤ 0.1mm), synchronously eliminating electromagnetic interference and capturing typical environmental parameters, ensuring that the temperature / humidity response time is ≤ 100ms and the ozone detection accuracy is ±1ppm.

[0029] The nanosecond pulse power supply 1 has an continuously adjustable output voltage amplitude of 20-60kV. It is connected to the sensors through a built-in dedicated control unit. The analog or digital signals output by the temperature, humidity and ozone sensors are first filtered, amplified and electrically isolated by an isolated signal conditioning circuit, and then acquired in real time by a microcontroller (MCU) through an analog-to-digital converter (ADC). The MCU runs a fuzzy PID control algorithm to calculate the control amount in real time based on the deviation between the sensor data and the set value, and outputs analog instructions to the high-voltage modulation circuit through a digital-to-analog converter (DAC). Finally, it dynamically adjusts the output voltage amplitude of the nanosecond pulse, thus forming a complete, isolated and fast-responding intelligent closed-loop control system to adapt to the differentiated plasma response characteristics of different types and forms of grains, ensuring uniform processing results.

[0030] The nanosecond pulse power supply 1 has a pulse rise edge of 100ns. The steep rise edge combined with the nanosecond pulse width forms an instantaneous high voltage field, which efficiently excites non-equilibrium plasma in the gaps between grain particles. This characteristic allows energy to be preferentially injected into the electron system (electron temperature Te > 5eV), while the temperature of ions and neutral particles (Ti, Tn < 40℃) is maintained at near-ambient low temperature, generating a large-volume diffuse plasma plume. Simultaneously, three-order optimizations are achieved: 1) suppressing the transition from electron avalanche to arc discharge; 2) limiting Joule heat accumulation to ensure that the depth of thermal damage to grain is ≤ 50μm; 3) suppressing the generation of long-lived harmful chemical residues through non-equilibrium reaction characteristics, which is more conducive to their generation in the gaps between grain particles.

[0031] The dielectric layer 3 is made of polytetrafluoroethylene and has a thickness of 0.3 cm. The grounding metal casing 4 is made of 304 stainless steel and has a thickness of 0.2 cm.

[0032] The dielectric layer 3 and the grounded metal outer shell 4 are coaxially nested to form a cylindrical plasma treatment cavity. Its structural parameters are: axial length 70.0±0.5cm, outer diameter 9.0±0.1cm, and composite wall thickness 0.5±0.05cm. The dielectric layer 3 realizes a triple composite protection mechanism: 1) suppresses spark / arc breakdown between electrodes through an insulating barrier; 2) blocks ≥95% of high-energy secondary electrons and metal ions from bombarding and sputtering the electrodes, so that the annual corrosion rate of the electrodes is ≤0.1μm; 3) regulates the plasma heat conduction path to control the overall thermodynamic temperature in the treatment cavity within the range of 35±3℃, and simultaneously achieves the core protection indicators of grain surface thermal damage layer thickness ≤50μm and grain internal temperature rise ΔT <2℃.

[0033] The spiral blade 8 is made of polytetrafluoroethylene composite material. Under the strong electric field environment established between the high-voltage electrode 2 and the grounded metal shell 4, polytetrafluoroethylene itself has extremely low carrier mobility and conductivity, which fundamentally eliminates the possibility of forming additional conductive channels or leakage current through the blade body, ensuring that the discharge energy is concentrated in the preset plasma generation area. In addition, polytetrafluoroethylene material has excellent chemical inertness, low outgassing rate and plasma erosion resistance, which can effectively prevent the metal blade from introducing metal contamination particles in the plasma environment due to sputtering, evaporation or chemical reaction, interfering with the plasma chemical composition, or even causing unstable changes in the discharge mode.

[0034] The spiral blade 8 is made of polytetrafluoroethylene composite material with an axial length of 65±0.3cm and an outer diameter of 6.0±0.1cm. By controlling the high stiffness characteristics of the material (flexural modulus ≥4GPa) in conjunction with the structural dimensions, it is ensured that the deformation deflection under self-weight and 1500rpm rotation conditions is <0.1mm, eliminating the risk of mechanical collision with the high voltage electrode 2.

[0035] The drive motor 7 is a variable frequency speed control motor, which controls the speed to ensure that the grain passes through the processing zone at a uniform speed.

[0036] Material enters the equipment through inlet 9 and is conveyed at a uniform speed of 1.2 m / min through a processing channel 70 cm long and 8 cm in diameter by shaftless spiral blades 8. During this process, high-voltage electrode 2, driven by nanosecond pulse power supply 1 with an amplitude of 20 kV and a rise time of 100 ns, excites uniform low-temperature plasma within the cylindrical channel formed by dielectric layer 3 and grounded metal shell 4. This plasma deeply sterilizes and inactivates the transported grain, effectively eliminating harmful microorganisms such as Aspergillus flavus without causing thermal damage to the grain. Temperature and humidity sensors 5 and ozone sensors 6 are located in the middle of the channel to monitor environmental parameters in real time.

[0037] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A nanosecond pulsed plasma pipeline grain conveying, disinfecting and killing integrated device, characterized in that, It comprises: nanosecond pulse power supply (1), high voltage electrode (2), dielectric layer (3), grounded metal shell (4), drive motor (7), spiral blade (8), feed inlet (9) and discharge outlet (10); the dielectric layer (3) and the grounded metal shell (4) are nested to form a cylindrical treatment channel, and the high voltage electrode (2) is coaxially arranged in the center of the cylindrical treatment channel; the cylindrical treatment channel is provided with a feed inlet (9) at one end; the other end is provided with a discharge outlet (10); the spiral blade (8) is connected with the drive motor (7), and the metal shell (4) is provided with a temperature and humidity sensor (5) and an ozone sensor (6) on the inner wall, and the nanosecond pulse power supply (1) dynamically adjusts the output parameters according to the feedback of the temperature and humidity sensor (5) and the ozone sensor (6); The spiral blade (8) is a continuous spiral belt structure with equal pitch and equal thickness, and the spiral angle is 15°-20°; the spiral blade (8) coaxially surrounds the high voltage electrode (2), and an annular gap channel is formed between the two.

2. The nanosecond pulsed plasma pipeline grain conveying, disinfecting and killing integrated device according to claim 1, characterized in that: The high voltage pulse amplitude output by the nanosecond pulse power supply (1) is continuously adjustable at 20-60 kV, and the pulse rising edge is ≤100 ns.

3. The nanosecond pulsed plasma ducted grain conveying, disinfecting and killing integrated device according to claim 2, characterized in that: The high voltage electrode (2) is a stainless steel rod with polished surface, and the minimum gap between the high voltage electrode (2) and the inner edge of the spiral blade (8) is >1 cm.

4. The nanosecond pulsed plasma pipeline grain conveying, disinfecting and killing integrated device according to claim 3, characterized in that: The material of the dielectric layer (3) is polytetrafluoroethylene, and the thickness is 0.2-0.5 cm.

5. The nanosecond pulsed plasma ducted grain conveying, disinfecting and killing integrated device according to claim 4, characterized in that: The spiral blade (8) is made of polytetrafluoroethylene-based composite material, the outer diameter is 5-8 cm, and the axial length is 50-80 cm.

6. The nanosecond pulsed plasma ducted grain conveying, disinfecting and killing integrated device according to claim 5, characterized in that: The grounded metal shell (4) is made of 304 stainless steel, and the thickness is 0.1-0.4 cm.

7. The nanosecond pulsed plasma ducted grain conveying, disinfecting and killing integrated device according to claim 6, characterized in that: The sensing end face of the temperature and humidity sensor (5) and the ozone sensor (6) is conformal and flush with the inner wall of the metal shell (4), and the protruding height is <0.1 mm.

8. The nanosecond pulsed plasma ducted grain conveying, disinfecting and killing integrated device according to claim 7, characterized in that: The drive motor (7) is a variable frequency speed regulation motor connected with the spiral blade (8) through a shaft coupling.

9. The nanosecond pulsed plasma ducted grain conveying, disinfecting and killing integrated device according to claim 8, characterized in that: It also includes a control unit connected with the temperature and humidity sensor (5) and the ozone sensor (6) for receiving the signals of the temperature and humidity sensor (5) and the ozone sensor (6) and feeding back the output parameters of the nanosecond pulse power supply (1).

10. The nanosecond pulsed plasma ducted grain conveying, disinfecting and killing integrated device according to claim 9, characterized in that: The device realizes the synchronous operation of grain conveying and plasma sterilization, and the length of the cylindrical treatment channel is 60-80 cm and the outer diameter is 5-10 cm.

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