Micro-nano bubble generator, hydroponic system and use method

Abstract

The invention relates to the technical field of agricultural engineering cultivation, and discloses a micro-nano bubble generator, a hydroponic system and a using method.The micro-nano bubble generator comprises a bubble generating pipe, and the micro-nano bubble generator is sequentially provided with a primary bubble generating unit and a secondary bubble generating unit in the liquid flowing direction, the primary bubble generating unit comprises a waterproof breathable film and an air inlet assembly, and the waterproof breathable film is arranged in an inner cavity of the bubble generating pipe; an inner cavity of the bubble generating pipe is divided into a liquid cavity and a gas cavity which are isolated from each other, and an air inlet communicated with the gas cavity is formed in the side wall of the bubble generating pipe; the air inlet assembly is communicated with the air inlet hole; the secondary bubble generation unit comprises an impeller and a driving part, a two-stage bubble generation mechanism is adopted, the primary bubble generation unit performs primary dispersion on gas by utilizing a waterproof breathable film, and the secondary bubble generation unit performs powerful mechanical shearing on primary micro bubbles through high-speed rotation of the impeller, so that secondary crushing and homogenization of the bubbles are realized; the bubble size distribution range is obviously reduced, and the uniformity and stability of a bubble group are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of agricultural engineering cultivation technology, and in particular to a micro / nano bubble generator, a hydroponic system, and a method of using it. Background Technology

[0002] Currently, the average grade of arable land in my country is only 4.76, with low-grade arable land (grades 7 to 10) accounting for as much as 22%. Traditional soil cultivation methods are limited by both the quality and area of ​​arable land, making it difficult to meet the needs of efficient modern agricultural production. Therefore, it is urgent to explore new planting methods that require less land and yield higher output. Hydroponics, as a feasible technology to address this challenge, has unique advantages: First, the nutrient solution composition can be precisely configured according to the growth needs of different crops, directly providing key growth factors such as water, nutrients, and oxygen to the crop roots instead of soil. Second, artificial light sources can simulate and controllably adjust the natural photoperiod, ensuring stable photosynthesis while remaining unaffected by natural weather changes. Third, compared with traditional soil cultivation, hydroponic crops are not affected by arable land conditions and can be grown in non-arable areas (such as factories and rooftops), significantly saving arable land resources. It has become an important production technology for efficient crop cultivation in the context of current arable land scarcity.

[0003] As agricultural technology advances towards precision and intelligence, automated production has become a key means to improve hydroponic efficiency. In leading agricultural technology countries such as the Netherlands and Israel, dynamic environmental control technology based on real-time parameter monitoring has been applied to hydroponic systems. Based on different crop growth stages, automated PLC control systems dynamically adjust supply strategies, precisely controlling parameters such as temperature and humidity, nutrient solution flow, and light duration in the hydroponic environment. This significantly improves production efficiency and crop quality stability while reducing the cost of manual intervention. Chinese researchers are also continuously focusing on the research and development of automated hydroponic technology. By optimizing automatic control systems and improving nutrient solution circulation and parameter feedback logic, they are driving the transformation of hydroponic technology from semi-manual control to fully intelligent adaptation, further releasing the potential for large-scale production of hydroponic systems.

[0004] For example, patent application CN115413572A discloses a micro-nano bubble hydroponic device and system. The micro-nano bubble hydroponic device includes a circulation component and at least one planting component. One side of the circulation component is connected to the planting component through a water inlet unit, and the side of the circulation component away from the water inlet unit is connected to the planting component through a water outlet unit. The circulation component includes a stirring tank and a micro-nano bubble generator. The micro-nano bubble generator performs high-pressure treatment on the nutrient solution, and the stirring tank is used to achieve automatic proportioning and circulation of the nutrient solution. At the same time, a controller is provided to achieve automatic control of the planting component and the circulation component. This technology improves the automation level and oxygen supply efficiency of the hydroponic system to a certain extent. However, the existing micro-nano bubble hydroponic devices and systems have a wide range of bubble size distribution and poor uniformity. They cannot adapt to the dynamic needs of dissolved oxygen and nutrient solution delivery according to different growth stages of crops, which limits the further improvement of the growth rate and quality of hydroponic crops. Summary of the Invention

[0005] The technical problem to be solved by this invention is that the existing micro-nano bubble hydroponic devices and micro-nano bubble generators in hydroponic systems produce bubbles with a wide range of size distribution and poor uniformity. They cannot be adapted to the dynamic needs of dissolved oxygen and nutrient transport according to different growth stages of crops, thus limiting the further improvement of the growth rate and quality of hydroponic crops.

[0006] To address the aforementioned technical problems, this invention provides a micro / nano bubble generator, comprising: The first bubble generating tube has an internal waterproof and breathable membrane that divides the inner cavity of the first bubble generating tube into a gas cavity and a liquid cavity. The second bubble generating tube is connected to the outlet of the liquid chamber, and an impeller assembly is rotatably installed inside the second bubble generating tube. The liquid inlet assembly is connected to the inlet of the liquid chamber and is used to drive the liquid to pass through the first bubble generating tube and the second bubble generating tube in sequence. The air intake assembly, which is connected to the gas chamber, is used to supply gas to the gas chamber; The drive unit has its output shaft connected to the impeller assembly and is used to drive the impeller assembly to rotate.

[0007] Preferably, it also includes a liquid inlet pipe, the liquid inlet assembly is connected to the inlet of the liquid inlet pipe, the outlet of the liquid inlet pipe is connected to the inlet of the liquid inlet chamber, and the liquid inlet assembly drives the liquid to pass through the liquid inlet pipe, the first bubble generating pipe and the second bubble generating pipe in sequence.

[0008] Preferably, the diameter of the inlet pipe gradually decreases along the direction of liquid flow; The diameter of the second bubble generating tube gradually increases along the direction of liquid flow.

[0009] Preferably, the diameter of the first bubble generating tube is the same along the liquid flow direction; the diameter of the first bubble generating tube is larger than the diameter of the outlet of the liquid inlet tube, and the diameter of the first bubble generating tube is larger than the diameter of the inlet of the second bubble generating tube, so as to form annular mounting steps on the inner wall at both ends of the first bubble generating tube. The water-proof and breathable membrane is annular, with its two ends fixed to each mounting step, so that the outer wall of the water-proof and breathable membrane and the inner wall of the first bubble generating tube form an annular gas cavity, and the inner cavity of the water-proof and breathable membrane forms a cylindrical liquid cavity. The side wall of the first bubble generating tube is provided with an air inlet that communicates with the annular gas chamber, and the air inlet assembly is connected to the air inlet. The inner cavity of the inlet pipe, the liquid cavity, and the inner cavity of the second bubble generating pipe are connected in sequence to form a liquid flow channel.

[0010] The present invention also provides a micro / nano bubble hydroponic system, including the aforementioned micro / nano bubble generator, and further comprising: A planting assembly for planting plants, which includes a liquid channel. PLC control system; The outlet of the second bubble generating tube is connected to the inlet end of the liquid channel in the planting component, and the outlet end of the liquid channel in the planting component is connected to the inlet component to form a liquid loop. The liquid inlet assembly drives the liquid to circulate within the liquid circuit; The PLC control system is electrically connected to the liquid inlet assembly, air inlet assembly, and drive unit, respectively.

[0011] Preferably, the planting components include: The annular pipe has a liquid channel formed inside. The annular pipe is equipped with an inlet and an outlet. The outlet of the second bubble generating pipe is connected to the inlet of the annular pipe, and the outlet of the annular pipe is connected to the inlet assembly. Multiple orifice plates are provided, with each orifice plate spaced apart in the inner cavity of the annular pipe. The surface of each orifice plate is perpendicular to the flow direction of the nutrient solution, and each orifice plate has multiple liquid passage holes. Planting baskets; multiple baskets are provided, each positioned in the gap between two adjacent perforated plates. Each basket contains plants, and each basket has a through hole at the bottom for the plant roots to pass through.

[0012] The present invention also provides a method for using the above-mentioned micro / nano bubble hydroponic system, comprising the following steps: S1. Prepare the nutrient solution and inject it into the storage tank; S2. Start the liquid inlet assembly to pump the nutrient solution into the bubble generation tube of the micro-nano bubble generator; S3. Start the air intake assembly to supply gas to the gas chamber in the bubble generating tube. The gas penetrates the water-proof and breathable membrane and enters the liquid chamber in the bubble generating tube to mix with the flowing nutrient solution and generate microbubbles. S4. Start the drive unit to drive the impeller to rotate, and shear the nutrient solution carrying primary microbubbles to break and refine the primary microbubbles into secondary microbubbles. S5. The nutrient solution rich in secondary microbubbles is delivered to the planting component for absorption by the plant roots, and then the nutrient solution is returned to the storage tank.

[0013] Preferably, in step S3, the air intake flow rate of the air compressor in the air intake assembly ranges from 100 mL / min to 300 mL / min, the water-proof and breathable membrane is made of polytetrafluoroethylene, and the water-proof and breathable membrane has multiple vents, each with a pore diameter of 0.5 μm to 0.8 μm, generating 0.5 × 10⁻⁶ microbubbles per primary. 8 From 0.7 × 10⁻⁶ cells / L to 0.7 × 10⁻⁶ cells / L 8 The number of microbubbles produced per L is 0.8 μm to 1 μm on average.

[0014] Preferably, in step S4, the driving component is a motor with a frequency of 40kHz to 48kHz; the impeller speed is 2500rpm to 2900rpm; and the number of secondary microbubbles generated is 1.7×10⁻⁶. 8 From 100 cells / L to 2.0 × 10⁻⁶ 8 The number of microbubbles produced per L is 0.1 μm to 0.2 μm on average.

[0015] Preferably, in step S5, the perforated plate material in the planting component is a mixed fiber ester, and the diameter of the liquid passage holes on the perforated plate is 0.7 mm to 1 mm.

[0016] Compared with the prior art, the micro / nano bubble generator of this invention has the following advantages: The micro-nano bubble generator of this invention employs a two-stage bubble generation mechanism. First, a water-proof and breathable membrane is used to initially disperse the gas, forming relatively uniform primary microbubbles through its uniform microporous structure, laying the foundation for precision. Then, the high-speed rotation of the impeller assembly performs strong mechanical shearing on the primary microbubbles, achieving secondary breakage and homogenization of the bubbles. This significantly reduces the bubble size distribution range and greatly improves the uniformity and stability of the bubble cluster. Operators can control the size, density, and distribution of the final secondary microbubbles in real time by adjusting the air intake flow rate of the air intake assembly and the rotation speed of the impeller assembly. This allows the bubble characteristics to flexibly adapt to the dynamic needs of different crops and their various growth stages for dissolved oxygen and nutrient solution transport efficiency, providing a reliable technical guarantee for improving the growth rate and quality of hydroponic crops. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the micro-nano bubble hydroponic system provided in an embodiment of the present invention; Figure 2 This is an overall schematic diagram of the connection structure between the liquid inlet pipe, the first bubble generating pipe, and the second bubble generating pipe in the micro / nano bubble generator provided in an embodiment of the present invention. Figure 3 This is a partial cross-sectional view of the connection structure between the liquid inlet pipe, the first bubble generating pipe, and the second bubble generating pipe in the micro / nano bubble generator provided in an embodiment of the present invention.

[0018] In the diagram, 1. First bubble generating tube; 101. Waterproof and breathable membrane; 102. Gas chamber; 103. Liquid chamber; 104. Mounting step; 2. Second bubble generating tube; 201. Impeller assembly; 3. Liquid inlet assembly; 301. Liquid storage tank; 302. Water pump; 303. Liquid flow meter; 4. Air inlet assembly; 401. Air compressor; 402. Gas flow meter; 5. Drive component; 6. Liquid inlet pipe; 7. Planting assembly; 701. Annular pipe; 702. Orifice plate; 703. Planting basket; 8. Fluorescent lamp; 9. Temperature controller; 10. Pressure sensor; 11. PLC control system; 12. PC system. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0020] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] It should be understood that the terms "first," "second," etc., are used in this invention to describe various types of information, but these terms are not limited to them; they are only used to distinguish information of the same type from one another. For example, without departing from the scope of this invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] like Figures 1 to 3 As shown, a preferred embodiment of the present invention provides a micro / nano bubble generator, comprising: The first bubble generating tube 1 has a water-proof and air-permeable membrane 101 inside, which divides the inner cavity of the first bubble generating tube 1 into a gas cavity 102 and a liquid cavity 103. The second bubble generating tube 2 is connected to the outlet of the liquid chamber 103, and an impeller assembly 201 is rotatably provided inside the second bubble generating tube 2. The liquid inlet assembly 3 is connected to the inlet of the liquid chamber 103 and is used to drive the liquid to pass through the first bubble generating tube 1 and the second bubble generating tube 2 in sequence. The air intake assembly 4 is connected to the gas chamber 102 and is used to supply gas to the gas chamber 102. The drive component 5 has its output shaft connected to the impeller assembly 201 and is used to drive the impeller assembly 201 to rotate.

[0024] The micro-nano bubble generator of this invention employs a two-stage bubble generation mechanism. First, the gas is initially dispersed using a water-proof and breathable membrane 101, forming relatively uniform primary microbubbles through its uniform microporous structure, laying the foundation for precision. Then, the high-speed rotation of the impeller assembly 201 performs strong mechanical shearing on the primary microbubbles, achieving secondary breakage and homogenization of the bubbles. This significantly reduces the bubble size distribution range and greatly improves the uniformity and stability of the bubble cluster. Operators can control the size, density, and distribution of the final secondary microbubbles in real time by adjusting the air intake flow rate of the air intake assembly 4 and the rotation speed of the impeller assembly 201. This allows the bubble characteristics to flexibly adapt to the dynamic needs of different crops and their various growth stages for dissolved oxygen and nutrient solution transport efficiency, providing a reliable technical guarantee for improving the growth rate and quality of hydroponic crops.

[0025] Specifically, it also includes a liquid inlet pipe 6, a liquid inlet assembly 3 connected to the inlet of the liquid inlet pipe 6, and an outlet of the liquid inlet pipe 6 connected to the inlet of the liquid inlet chamber. The liquid inlet assembly 3 drives the liquid to pass through the liquid inlet pipe 6, the first bubble generating pipe 1, and the second bubble generating pipe 2 in sequence.

[0026] Specifically, such as Figure 2 and Figure 3As shown, the diameter of the inlet pipe 6 gradually decreases along the direction of liquid flow; the diameter of the second bubble generating pipe 2 gradually increases along the direction of liquid flow.

[0027] The tapering design of the inlet pipe 6 accelerates the flow rate of the inflowing liquid, increases the fluid kinetic energy, and provides more energy for the subsequent generation and breakup of bubbles. In addition, the tapering design of the second bubble generating pipe 2 reduces the fluid flow rate when the liquid flows out of the second bubble generating pipe 2, so that the liquid flow rich in secondary microbubbles can be smoothly discharged, ensuring the size uniformity and dispersion stability of the microbubble group.

[0028] Specifically, such as Figure 2 and Figure 3 As shown, the diameter of the first bubble generating tube 1 is the same along the liquid flow direction; the diameter of the first bubble generating tube 1 is larger than the diameter of the outlet of the liquid inlet tube 6, and the diameter of the first bubble generating tube 1 is larger than the diameter of the inlet of the second bubble generating tube 2, so as to form annular mounting steps 104 on the inner wall at both ends of the first bubble generating tube 1 in the axial direction. The water-proof and breathable membrane 101 is annular, and its two ends are fixed to each mounting step 104, so that the outer wall of the water-proof and breathable membrane 101 and the inner wall of the first bubble generating tube 1 form an annular gas cavity 102, and the inner cavity of the water-proof and breathable membrane 101 forms a cylindrical liquid cavity 103. The first bubble generating tube 1 has an air inlet hole on its side wall that communicates with the annular gas chamber 102, and the air inlet assembly 4 communicates with the air inlet hole. The inner cavity of the liquid inlet pipe 6, the liquid cavity 103, and the inner cavity of the second bubble generating pipe 2 are connected in sequence to form a liquid flow channel.

[0029] The annular mounting steps 104 at both ends of the first bubble generating tube 1 reliably fix the annular water-proof and breathable membrane 101, thereby dividing the interior of the first bubble generating tube 1 into an inner and outer spaced liquid chamber 103 and a gas chamber 102, ensuring the sealing of gas-liquid separation and the stability of long-term operation; the annular gas chamber 102 provides a stable buffer space for gas to penetrate the water-proof and breathable membrane 101 and mix fully with the liquid, which is conducive to generating more uniform primary microbubbles.

[0030] Specifically, the air intake assembly 4 includes an air compressor 401 and a gas flow meter 402 connected in sequence, with one end of the gas flow meter 402 connected to the air intake port.

[0031] The air compressor 401 provides a stable air source, and the gas flow meter 402 can monitor and control the intake air volume in real time, enabling operators to precisely adjust the total amount of gas penetrating the water-proof and breathable membrane 101 according to actual needs, ensuring that the number and size of microbubbles generated at one time remain highly stable.

[0032] Specifically, the liquid inlet assembly 3 includes a liquid storage tank 301, and a water pump 302 and a liquid flow meter 303 connected in sequence. The water pump 302 is installed inside the liquid storage tank 301, and one end of the liquid flow meter 303 is connected to the inlet of the liquid inlet pipe 6.

[0033] Specifically, the driving component 5 is a motor, which is located at the end of the liquid inlet pipe 6. The impeller assembly 201 is located inside the second bubble generating pipe 2. The output shaft of the motor passes through the liquid inlet pipe 6 and the liquid chamber 103 inside the first bubble generating pipe 1 and enters the second bubble generating pipe 2. The impeller assembly 201 includes two impellers, both of which are rotatably mounted on the output shaft of the motor.

[0034] By placing the motor externally, direct contact between the motor and the nutrient solution is avoided, improving the durability and safety of the equipment. Operators can adjust the motor speed to flexibly control the impeller speed, thereby precisely controlling the shear strength and dynamically adjusting the fineness and size distribution of the secondary microbubbles.

[0035] like Figure 1 As shown, the present invention also provides a micro / nano bubble hydroponic system, including the aforementioned micro / nano bubble generator, and the micro / nano bubble hydroponic system further includes: Planting component 7 is used for planting plants and has a liquid channel inside. PLC control system 11; The outlet of the second bubble generating tube 2 is connected to the inlet end of the liquid channel in the planting component 7, and the outlet end of the liquid channel in the planting component 7 is connected to the inlet component 3 to form a liquid circuit. Liquid inlet assembly 3 drives the liquid to circulate within the liquid circuit; The PLC control system 11 is electrically connected to the liquid inlet assembly 3, the air inlet assembly 4, and the drive unit 5, respectively.

[0036] The aforementioned micro-nano bubble generator is integrated into the micro-nano bubble hydroponic system. The micro-nano bubble generator continuously injects micro-bubbles of controllable size and concentration into the nutrient solution through a two-stage bubble generation mechanism. When the nutrient solution rich in uniformly sized micro-bubbles flows through the planting component 7, it can greatly improve the dissolved oxygen level of the rhizosphere environment and the mass transfer efficiency of nutrients, directly promoting crop root development and nutrient absorption. The PLC control system 11 adjusts the working parameters of the liquid inlet component 3, the air inlet component 4, and the drive component 5 in a coordinated manner according to the set pressure range, controlling the gas and liquid flow rate and pressure within the set range, thereby ensuring the continuity and efficiency of the bubble generation process.

[0037] Specifically, the PLC control system 11 is electrically connected to the water pump 302 of the liquid inlet assembly 3, the air compressor 401 of the air inlet assembly 4, and the motor 5, which serves as the drive component. Furthermore, a mounting hole is provided on the side wall of the second bubble generating tube 2, and a pressure sensor 10 is installed in this mounting hole via a threaded connection. The sensing end of the pressure sensor 10 is in direct contact with the liquid inside the second bubble generating tube 2, used to detect the liquid pressure near the working area of ​​the impeller assembly 201 in real time. This pressure sensor 10 is electrically connected to the PLC control system 11, feeding back the pressure signal to the PLC control system 11 in real time. The PLC control system 11 adjusts the operating parameters of the water pump 302, the air compressor 401, and the motor in a coordinated manner based on the real-time pressure test data, ensuring that the pressure is within the set pressure range.

[0038] Specifically, planting component 7 includes: The annular pipe 701 has a liquid channel formed in its inner cavity. The annular pipe 701 is provided with an inlet and an outlet. The outlet of the second bubble generating pipe 2 is connected to the inlet of the annular pipe 701, and the outlet of the annular pipe 701 is connected to the inlet assembly 3. Multiple orifice plates 702 are provided, and each orifice plate 702 is arranged at intervals in the inner cavity of the annular pipe 701. The plate surface of each orifice plate 702 is perpendicular to the flow direction of the nutrient solution, and each orifice plate 702 is provided with multiple liquid passage holes. Planting baskets 703 are provided in multiple ways. Each planting basket 703 is set in the interval between two adjacent perforated plates 702. Each planting basket 703 is planted with plants. Each planting basket 703 has a through hole at the bottom for the plant roots to pass through.

[0039] A perforated plate 702 is placed at regular intervals in the annular pipe 701 at every number of planting baskets 703 to ensure that microbubbles enter the annular pipe 701 evenly, preventing bubble aggregation or loss, enhancing oxygen mass transfer efficiency, and creating an oxygen-rich and highly efficient nutrient transport environment for plant roots.

[0040] Specifically, an orifice plate 702 is provided at the liquid outlet of the second bubble generating tube 2. The flow rate of the secondary microbubbles sheared by the impeller decreases in the gradually expanding second bubble generating tube 2, which poses a risk of local aggregation. The orifice plate 702 is set at the liquid outlet of the second bubble generating tube 2. The micropores evenly distributed on the orifice plate 702 prevent bubble aggregation or loss, and ensure the final uniformity of the output bubble size.

[0041] Specifically, each orifice plate 702 is welded to the inner wall of the annular pipe 701; the end of the second bubble generating pipe 2 is welded to the liquid inlet of the annular pipe 701.

[0042] Specifically, the top of the annular pipe 701 is evenly provided with multiple slots along its annular direction, and the lower part of each planting basket 703 is provided with a locking part that matches the slot, so that each planting basket 703 can be securely embedded in the slot one by one, thereby achieving radial and circumferential positioning of the planting basket 703 and effectively preventing it from shifting or tipping over during the circulation of nutrient solution; the upper opening of each planting basket 703 is higher than the top of the annular pipe 701, ensuring that the plant stems and leaves can extend upward normally and receive light; a fluorescent lamp 8 is suspended directly above the middle of the annular pipe 701, which provides uniform and sufficient light for all plants in the annular pipe 701.

[0043] Specifically, the liquid inlet pipe 6, the first bubble generating pipe 1, and the second bubble generating pipe 2 are all made of stainless steel.

[0044] Specifically, a temperature controller 9 is installed in the annular pipe 701. The temperature controller 9 contains a temperature sensor and a heating rod. The heating rod and the sensing end of the temperature sensor are both immersed in the nutrient solution in the annular pipe 701. The temperature sensor and the heating rod are electrically connected to the PLC control system 11. The temperature sensor detects the temperature of the nutrient solution in real time and feeds it back to the PLC control system 11. When the detected temperature is lower than the lower limit of the set range, the PLC controls the start of the heating rod to heat the nutrient solution in the storage tank 301. When the temperature rises to the upper limit of the set range, the PLC control system 11 issues a shutdown command to stop heating, thus forming a closed-loop control to achieve precise and automatic adjustment of the nutrient solution temperature.

[0045] Specifically, it also includes a PC system 12, which is electrically connected to the PLC control system 11. The PC system 12 is used for real-time recording of process parameters and effective setting of system process parameters.

[0046] The present invention also provides a method for using the above-mentioned micro / nano bubble hydroponic system, comprising the following steps: S1. Prepare the nutrient solution and inject it into the storage tank 301; S2. Start the liquid inlet assembly 3 to pump the nutrient solution into the bubble generation tube of the micro-nano bubble generator; S3. Start the air intake assembly 4 to supply gas to the gas chamber 102 in the bubble generating tube. The gas penetrates the water-proof and breathable membrane 101 and enters the liquid chamber 103 in the bubble generating tube to mix with the flowing nutrient solution and generate microbubbles. S4. Start the drive unit 5 to drive the impeller to rotate, and shear the nutrient solution carrying primary microbubbles, breaking and refining the primary microbubbles to form secondary microbubbles. S5. The nutrient solution rich in secondary microbubbles is delivered to the planting component 7 for absorption by the plant roots, and then the nutrient solution is returned to the storage tank 301.

[0047] Specifically, in step S1, the nutrient solution includes nutrients such as ammonium phosphate and potassium dihydrogen phosphate. The concentration of ammonium phosphate in the nutrient solution ranges from 100 mg / L to 115 mg / L, and the concentration of potassium dihydrogen phosphate in the nutrient solution ranges from 120 mg / L to 136 mg / L.

[0048] Specifically, in step S2, the flow rate of the liquid delivered by the water pump ranges from 85L / min to 100L / min.

[0049] Specifically, in step S3, the intake gas flow rate of the air compressor 401 in the intake assembly 4 ranges from 100 mL / min to 300 mL / min. The water-proof and breathable membrane 101 is made of polytetrafluoroethylene and has multiple vent holes with a pore diameter of 0.5 μm to 0.8 μm, generating 0.5 × 10⁻⁶ microbubbles per 10⁻⁶. 8 From 0.7 × 10⁻⁶ cells / L to 0.7 × 10⁻⁶ cells / L 8 The number of microbubbles produced per L is 0.8 μm to 1 μm on average.

[0050] Specifically, in step S4, the driving component 5 is a motor with a frequency of 40kHz to 48kHz; the impeller speed is 2500rpm to 2900rpm; and the number of secondary microbubbles generated is 1.7×10⁻⁶. 8 From 100 cells / L to 2.0 × 10⁻⁶ 8 The number of microbubbles produced per L is 0.1 μm to 0.2 μm on average.

[0051] Specifically, in step S5, the perforated plate 702 in the planting component 7 is made of mixed fiber ester, and the diameter of the liquid passage holes on the perforated plate 702 is 0.7mm to 1mm.

[0052] Specifically, it also includes: S6. Turn on the fluorescent lamp 8 and provide the crops with light intensity of 15W to 18W and light duration of 14h / d to 18h / d according to the set time period and duration. The distance between the fluorescent lamp 8 and the planting basket 703 is 25cm to 30cm. S7. Pressure sensor 10 receives changes in liquid pressure near the impeller and feeds them back to PLC control system 11. PLC control system 11 outputs electrical signals to adjust the working load of motor, air compressor 401 and water pump 302, and controls the gas and liquid flow rate and pressure within the set range. The pressure setting range is 1 MPa to 3 MPa. S8 and temperature controller 9 receive the temperature of the nutrient solution in the annular pipe 701 and feed it back to the PLC control system 11. The PLC control system 11 outputs an electrical signal to regulate the temperature within the set range, which is 20℃ to 25℃.

[0053] S9, PC system 12 and PLC control system 11 are electrically connected to ensure real-time recording of process parameters and effective setting of system process parameters.

[0054] Example 1: The circulating nutrient solution was prepared according to the following composition: ammonium phosphate 115 mg / L, potassium dihydrogen phosphate 136 mg / L, and pH adjusted to 6.0 with 100 mg / L citric acid. Under the conditions of an air flow rate of 0.3 L / min, an impeller speed of 2900 rpm, and a microbubble aeration time of 1 hour, the number of bubbles was 2.0 × 10⁻⁶. 8 The average size of the bok choy was 105nm to 115nm. The weight of the bok choy was measured 21 days after planting. The results were: plant height 15cm, plant width 23cm, root length 17cm, fresh weight 28g, soluble sugar 10%, and vitamin C content 370mg / g.

[0055] Example 2: The circulating nutrient solution was prepared according to the following composition: ammonium phosphate 115 mg / L, potassium dihydrogen phosphate 136 mg / L, and pH adjusted to 6.0 with 100 mg / L citric acid. Under the conditions of an air flow rate of 0.2 L / min, an impeller speed of 2900 rpm, and a microbubble aeration time of 1 hour, the number of bubbles was 1.87 × 10⁻⁶. 8 The average size of the bok choy was 163nm to 190nm. The weight of the bok choy was measured 21 days after planting. The results were: plant height 14cm, plant width 22cm, root length 14cm, fresh weight 26g, soluble sugar 7%, and vitamin C content 250mg / g.

[0056] Example 3: The circulating nutrient solution was prepared according to the following composition: ammonium phosphate 115 mg / L, potassium dihydrogen phosphate 136 mg / L, and pH adjusted to 6.0 with 100 mg / L citric acid. Under the conditions of an air flow rate of 0.3 L / min, an impeller speed of 2500 rpm, and a microbubble aeration time of 1 hour, the number of bubbles was 1.74 × 10⁻⁶. 8 The average size of the bok choy was 140nm to 184nm. The weight of the bok choy was measured 21 days after planting. The results were: plant height 10cm, plant width 18cm, root length 9cm, fresh weight 23g, soluble sugar 8%, and vitamin C content 225mg / g.

[0057] In summary, this invention provides a micro / nano bubble generator, a hydroponic system, and a method of use. The micro / nano bubble generator of this invention employs a two-stage bubble generation mechanism. The primary bubble generation unit utilizes a water-resistant and breathable membrane to initially disperse the gas, forming relatively uniform primary microbubbles through its uniform microporous structure, laying the foundation for precision. The secondary bubble generation unit uses the high-speed rotation of the impeller to perform strong mechanical shearing on the primary microbubbles, achieving secondary breakage and homogenization of the bubbles. This significantly reduces the bubble size distribution range and greatly improves the uniformity and stability of the bubble cluster. Operators can control the size, density, and distribution of the final secondary microbubbles in real time by adjusting the gas supply parameters of the air inlet component and the rotation speed of the drive component. This allows the bubble characteristics to flexibly adapt to the dynamic needs of different crops and their various growth stages for dissolved oxygen and nutrient transport efficiency, providing a reliable technical guarantee for improving the growth rate and quality of hydroponic crops.

[0058] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A micro-nano bubble generator, characterized by, The micro-nano bubble generator comprises: a first bubble generating pipe (1) internally provided with a water-proof air permeable film (101), which divides the inner cavity of the first bubble generating pipe (1) into a gas cavity (102) and a liquid cavity (103); a second bubble generating pipe (2) communicating with the outlet of the liquid cavity (103), and internally provided with an impeller assembly (201) rotatingly arranged; a liquid inlet assembly (3) communicating with the inlet of the liquid cavity (103) and used for driving liquid to pass through the first bubble generating pipe (1) and the second bubble generating pipe (2) in sequence; an air inlet assembly (4) communicating with the gas cavity (102) and used for supplying gas to the gas cavity (102); a driving member (5) with an output shaft connected with the impeller assembly (201) and used for driving the impeller assembly (201) to rotate.

2. The micro-nano bubble generator according to claim 1, wherein The micro-nano bubble generator further comprises a liquid inlet pipe (6), the liquid inlet assembly (3) communicates with the inlet of the liquid inlet pipe (6), and the outlet of the liquid inlet pipe (6) communicates with the inlet of the liquid cavity, so that the liquid inlet assembly (3) drives liquid to pass through the liquid inlet pipe (6), the first bubble generating pipe (1) and the second bubble generating pipe (2) in sequence. 3.The micro-nano bubble generator according to claim 2, characterized by, The pipe diameter of the liquid inlet pipe (6) gradually decreases along the liquid flow direction; The pipe diameter of the second bubble generating pipe (2) gradually increases along the liquid flow direction. 4.The micro-nano bubble generator according to claim 2, wherein The pipe diameter of the first bubble generating pipe (1) is the same along the liquid flow direction, the pipe diameter of the first bubble generating pipe (1) is greater than the pipe diameter of the outlet of the liquid inlet pipe (6), and the pipe diameter of the first bubble generating pipe (1) is greater than the pipe diameter of the inlet of the second bubble generating pipe (2), so as to form annular mounting steps (104) on the inner walls of the two axial ends of the first bubble generating pipe (1); The water-proof air permeable film (101) is annular, and the two ends of the water-proof air permeable film (101) are fixed on the mounting steps (104) respectively, so that the outer wall of the water-proof air permeable film (101) and the inner wall of the first bubble generating pipe (1) form the annular gas cavity (102), and the inner cavity of the water-proof air permeable film (101) forms the cylindrical liquid cavity (103); The side wall of the first bubble generating pipe (1) is provided with an air inlet hole communicating with the annular gas cavity (102), and the air inlet assembly (4) communicates with the air inlet hole; The inner cavities of the liquid inlet pipe (6), the liquid cavity (103) and the second bubble generating pipe (2) communicate in sequence to form a liquid flow channel.

5. A micro-nano bubble water cultivation system, characterized in that, The micro-nano bubble water culture system comprises the micro-nano bubble generator according to any one of claims 1-4, and further comprises: a planting assembly (7) used for planting plants, and internally provided with a liquid passage; a PLC control system (11); the outlet of the second bubble generating pipe (2) communicates with the liquid inlet end of the liquid passage in the planting assembly (7), and the liquid outlet end of the liquid passage in the planting assembly (7) communicates with the liquid inlet assembly (3), so as to form a liquid loop; the liquid inlet assembly (3) drives liquid to circulate and flow in the liquid loop; The PLC control system (11) is electrically connected with the liquid inlet assembly (3), the air inlet assembly (4) and the driving member (5) respectively. 6.The micro-nano bubble water cultivation system according to claim 5, characterized in that, The planting assembly (7) comprises: a ring-shaped pipeline (701), an inner cavity of the ring-shaped pipeline (701) forms the liquid channel, the ring-shaped pipeline (701) is provided with a liquid inlet and a liquid outlet, the outlet of the second bubble generating pipe (2) is communicated with the liquid inlet of the ring-shaped pipeline (701), and the liquid outlet of the ring-shaped pipeline (701) is communicated with the liquid inlet assembly (3); a plurality of hole plates (702) are arranged at intervals in the inner cavity of the ring-shaped pipeline (701), the plate surface of each hole plate (702) is perpendicular to the flow direction of the nutrient solution, and a plurality of liquid through holes are arranged on each hole plate (702); a plurality of planting baskets (703) are arranged at intervals between adjacent two hole plates (702), each planting basket (703) is planted with plants, and the bottom of each planting basket (703) is provided with a through hole for the roots of the plants to pass through.

7. A method of using the micro-nano bubble water farming system according to claim 5 or 6, characterized in that, The method comprises the following steps: S1, configuring a nutrient solution and injecting the nutrient solution into a storage tank (301); S2, starting the liquid inlet assembly (3) to pump the nutrient solution into the bubble generating pipe of the micro-nano bubble generator; S3, starting the air inlet assembly (4) to supply gas to the gas cavity (102) in the bubble generating pipe, the gas penetrates through the water-proof air-permeable membrane (101) into the liquid cavity (103) in the bubble generating pipe to mix with the flowing nutrient solution to generate primary micro-bubbles; S4, starting the driving member (5) to drive the impeller to rotate to shear the nutrient solution carrying the primary micro-bubbles to break and refine the primary micro-bubbles to form secondary micro-bubbles; S5, the nutrient solution rich in secondary micro-bubbles is transported to the planting assembly (7), after the plant roots absorb the nutrient solution, the nutrient solution flows back to the storage tank (301). 8.The method of using the micro-nano bubble water culture system according to claim 7, wherein, The air intake flow range of the air pump (401) in the air intake assembly (4) is 100 mL / min to 300 mL / min, the material of the water-proof air-permeable film (101) is polytetrafluoroethylene, the water-proof air-permeable film (101) is provided with a plurality of air holes, the diameter of each air hole is 0.5 μm to 0.8 μm, the number of the primary fine bubbles generated is 0.5×10 8 / L to 0.7×10 8 / L, and the average size of the primary fine bubbles generated is 0.8 μm to 1 μm. 9.The method of using the micro-nano bubble water culture system according to claim 8, wherein, In the step S4, the driving member (5) is a motor, the motor frequency is 40 kHz to 48 kHz; the impeller rotating speed is 2500 rpm to 2900 rpm; the generated secondary fine bubbles number is 1.7×10 8 to 2.0×10 8 / L, and the generated secondary fine bubbles average size is 0.1 μm to 0.2 μm. 10.The method of using the micro-nano bubble water culture system according to claim 9, wherein, In the step S5, the hole plate (702) in the planting assembly (7) is made of mixed fiber ester, and the pore size of the liquid through hole on the hole plate (702) is 0.7mm to 1mm.

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