A micro-nano bubble generating device

Abstract

The application provides a micro-nano bubble generating device, which comprises an upper part body, a lower part body and a flow channel assembly; at least one end of the upper part body or the lower part body is respectively provided with a liquid inlet flow channel and a gas inlet flow channel; the upper part body and the lower part body are connected through the flow channel assembly to form a turbulent flow cavity and a mixed liquid outlet which are in communication with each other; the turbulent flow cavity is in communication with the liquid inlet flow channel outlet and the gas inlet flow channel outlet respectively, and the negative pressure generated by the liquid pressurization into the turbulent flow cavity enables the gas to be sucked into the turbulent flow cavity; and the mixed liquid outlet is used for outputting micro-nano bubbles. The device has simple structure, low cost, small bubble particle size, fast oxygen dissolving efficiency and is very suitable for popularization into agricultural oxygenation irrigation production practice.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oxygenation irrigation, in particular to a micro-nano bubble generating device. BACKGROUND

[0002] Agricultural water resources are increasingly scarce in China, and micro-irrigation technologies such as underground drip irrigation can greatly improve the efficiency of agricultural water use, which is an important means to solve the shortage of agricultural water. However, micro-irrigation and other types of irrigation will exclude the air around the plant root zone during irrigation, resulting in a sharp decrease in the air permeability and oxygen level of the soil wet area around the plant roots, which greatly limits the oxygen uptake of the roots and is not conducive to crop growth and affects crop yield.

[0003] Due to the low solubility of oxygen in water, oxygen in agricultural irrigation water is mainly in the form of bubbles. The common oxygenation methods in agricultural irrigation include Venturi jet aeration, air compressor aeration, and chemical aeration. The bubbles generated by these mechanical oxygenation methods are large in size, short in retention time, and low in oxygen solubility efficiency, making it difficult to play an oxygenation role in long-distance micro-irrigation pipelines. Chemical oxygenation is currently mainly used in scientific research and experiments, and its long-term use may have adverse effects on the soil, which needs to be discussed before it can be applied to agricultural production.

[0004] In recent years, more advanced micro-nano bubble technology has been mainly applied in wastewater treatment, petrochemical industry, nuclear power molten salt, and other fields. Micro-nano bubbles have the characteristics of slow upward velocity, long duration, self-pressurization dissolution, and high gas dissolution efficiency due to their small size and large specific surface area, making them good air carriers for long-distance oxygenation irrigation. According to the principle of micro-nano bubble generation, micro-nano bubble generating devices can be divided into electrolytic type, pressurized gas dissolution type, dispersed air type, ultrasonic cavitation type, and photocatalytic type. The existing technology discloses a micro-nano bubble generator that uses a cutting net to cut bubbles in liquid to form micro-nano bubbles, but the manufacturing process of the cutting net is relatively high, and the micro-pores of the cutting net are easily clogged. The existing technology discloses a micro-nano bubble water preparation generator that first removes positive ions from air through ionization, then forces the negatively charged air to dissolve in water under pressure, and finally releases a large amount of micro-nano bubbles through an exhaust valve. However, the device has many supporting facilities, occupies a large space, and has high cost. The existing technology discloses a variable pitch micro-nano bubble generating device that uses a continuous spiral variable pitch rectifier blade to stabilize the flow state of the micro-nano bubble liquid, but the cavity structure with the built-in rectifier blade is complex and difficult to process.

[0005] The bubble forming performance and application range of various micro-nano bubble generators in the prior art are quite different, but there are problems such as large device size, complex structure, high cost, etc., which cannot be applied to micro-irrigation systems in a large area, and cannot be popularized to the field of agricultural production. Therefore, the invention of a micro-nano bubble generator with small size, easy to install and disassemble, simple structure and low manufacturing cost is the key to solving the above-mentioned device vacancy in the field of agricultural oxygenation irrigation. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application provides a micro-nano bubble generator, which has a simple structure, low cost, small bubble size, fast oxygen dissolving efficiency, and is very suitable for popularization in the field of agricultural oxygenation irrigation.

[0007] The present application achieves the above technical objectives through the following technical means.

[0008] A micro-nano bubble generator, comprising an upper body, a lower body and a flow channel assembly; at least one end of the upper body or the lower body is respectively provided with a liquid inlet flow channel and a gas inlet flow channel;

[0009] The upper body and the lower body are connected by the flow channel assembly to form at least a turbulent flow chamber and a mixed liquid outlet in communication with each other; the turbulent flow chamber is in communication with the outlet of the liquid inlet flow channel and the outlet of the gas inlet flow channel, respectively, and the negative pressure generated by the pressurized liquid entering the turbulent flow chamber causes the gas to be sucked into the turbulent flow chamber; the mixed liquid outlet is used to output micro-nano bubbles.

[0010] Further, the flow channel assembly is composed of a plurality of gaskets or irregular gaskets, and the plurality of gaskets are installed on the upper body or / and the lower body.

[0011] Further, the ratio of the length to the diameter of the liquid inlet flow channel is not less than 10; the ratio of the diameter of the gas inlet flow channel to the diameter of the liquid inlet flow channel is in the range of 0.6-0.75.

[0012] Further, the distance between the center axis of the gas inlet flow channel and the center axis of the liquid inlet flow channel is not more than 2.5mm.

[0013] Further, the thickness of the turbulent flow chamber is 0.2-0.5mm.

[0014] Further, the gas inlet of the gas inlet flow channel is connected with a gas flow meter for detecting the amount of gas suction.

[0015] Further, the flow channel assembly is composed of circular gaskets uniformly distributed between the upper body and the lower body, and the inscribed circle between the circular gaskets uniformly distributed forms a turbulent flow chamber, and the cavity between adjacent circular gaskets forms a mixed liquid outlet.

[0016] Further, the flow channel assembly is a flow channel gasket, a groove is arranged on the surface of the flow channel gasket, the groove is communicated with the liquid inlet flow channel and the gas inlet flow channel respectively, and is used for forming a turbulent flow cavity; at least one gradually expanded opening is arranged on the groove, and is used for forming a mixed liquid outlet.

[0017] Further, the diameter of the liquid inlet flow channel is 2.0-3.0 mm, and the diameter of the gas inlet flow channel is 1.0-1.5 mm.

[0018] Further, the one end of the upper part body and the one end of the lower part body are respectively provided with the liquid inlet flow channel and the gas inlet flow channel; and the one end of the upper part body and the one end of the lower part body are symmetrically connected.

[0019] The beneficial effects of the present application are as follows:

[0020] 1. The micro-nano bubble generating device, the gas inlet flow channel is arranged beside the liquid inlet flow channel, the high-speed liquid flows through the gas inlet to generate a negative pressure suction effect, and no additional gas inlet system is needed.

[0021] 2. The micro-nano bubble generating device adopts a split structure, and is split into an upper part body, a lower part body and an intermediate gasket, so that the manufacturing difficulty of the device is simplified, the turbulent flow cavity is formed by a slit formed by the three parts, and the effect of repeatedly breaking bubbles by using turbulent kinetic energy can be achieved, the turbulent flow cavity does not need to be additionally processed, and the manufacturing cost is reduced.

[0022] 3. The micro-nano bubble generating device adopts a vertical liquid inlet and a lateral liquid outlet, and the gas flow channel outlet is arranged in the turbulent flow cavity, so that the device structure is small and compact.

[0023] 4. The micro-nano bubble generating device, the flow channel assembly can be replaced, the hard gasket with different thicknesses or the intermediate gasket with different fixed flow channels can be suitable for different working conditions, and more types of gaskets can be developed according to actual working conditions.

[0024] 5. The micro-nano bubble generating device, when the upper part body and the lower part body are connected in the same direction, a bidirectional liquid inlet mode is adopted, so that the bubble generation rate can be improved, and the liquid treatment amount per unit time can be increased. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. The drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0026] Figure 1 A three-dimensional view of the micro-nano bubble generating device according to Embodiment 1 of the present application.

[0027] Figure 2 A front view of the micro-nano bubble generating device according to Embodiment 1 of the present application.

[0028] Figure 3 A-A sectional view of the micro-nano bubble generating device according to Embodiment 1 of the present application. Figure 2

[0029] B-B sectional view of the micro-nano bubble generating device according to Embodiment 1 of the present application. Figure 4 Figure 2 Partial enlarged view of the turbulent flow cavity.

[0030] Figure 5 Three-dimensional view of the flow channel gasket.

[0031] Figure 6 Sectional view of the flow channel gasket.

[0032] Figure 7 Structure schematic view of the micro-nano bubble generating device according to Embodiment 3 of the present application.

[0033] Figure 8 Water body dissolved oxygen change curve of the micro-nano bubble generating device according to the present application when running and after standing.

[0034] Figure 9 Comparison diagram of the micro-nano bubble generating device according to the present application and the bubble particles generated by the prior art, wherein (a) is a diagram of the bubble particles generated by the prior art, and (b) is a diagram of the bubble particles generated by the micro-nano bubble generating device according to the present application.

[0035] Figure 10 In the diagram:

[0036] In the diagram:

[0037] 1 - upper part body; 2 - lower part body; 3 - gasket; 4 - liquid inlet; 5 - liquid inlet flow channel; 6 - gas inlet; 7 - gas inlet flow channel; 8 - turbulent flow cavity; 9 - mixed liquid outlet; 10 - bolt; L1 - length of the device; L11 - length of the upper part body; L12 - length of the lower part body; L2 - thickness of the middle gasket; L21 - thickness of the turbulent flow cavity; L3 - length of the liquid inlet; L4 - length of the gas inlet; L5 - distance of the fixed screw pitch device center axis; L6 - distance of the gas inlet center from the bottom of the upper part body; L7 - distance between the gas inlet flow channel and the liquid inlet flow channel; d1 - diameter of the device; d2 - diameter of the liquid inlet; d21 - diameter of the liquid inlet flow channel; d3 - diameter of the gas inlet; d31 - diameter of the gas inlet flow channel; d4 - inner diameter of the middle gasket; d5 - outer diameter of the middle gasket. DETAILED DESCRIPTION

[0038] ​Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals and characters throughout the figures denote the same elements or elements having the same function. The embodiments described below are exemplary and are intended to be illustrative of the present application and are not to be construed as limiting the present application.

[0039] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are merely intended to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0040] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0041] As shown in Figure 1 The micro-nano bubble generating device of the present application comprises an upper body 1, a lower body 2 and a flow channel assembly. At least one end of the upper body 1 or the lower body 2 is respectively provided with a liquid inlet flow channel 5 and a gas inlet flow channel 7. The upper body 1 and the lower body 2 are connected by the flow channel assembly to form at least a turbulent flow cavity 8 and a mixed liquid outlet 9 in communication with each other. The turbulent flow cavity 8 is in communication with the outlet of the liquid inlet flow channel 5 and the outlet of the gas inlet flow channel 7, respectively. The negative pressure generated by the liquid pressurization into the turbulent flow cavity 8 causes the gas to be sucked into the turbulent flow cavity 8. The mixed liquid outlet 9 is used to output micro-nano bubbles.

[0042] The working principle of the micro-nano bubble generating device is that liquid medium flows into the liquid inlet 4 into the liquid flow channel 5, the high-speed liquid in the liquid flow channel 5 flows into the narrow turbulent cavity 8 formed by the flow channel assembly between the upper part body 1 and the lower part body 2, the high-speed liquid in the turbulent cavity 8 generates negative pressure, and part of the gas in the gas inlet flow channel 7 is driven to form a mixed liquid, the mixed liquid in the turbulent cavity 8 is diffused radially or according to a certain flow channel, the pressure is rapidly increased, and the mixed liquid is broken into small bubbles under high speed and high pressure, the small bubbles in the turbulent cavity are diffused to the surrounding through the mixed liquid outlet, and finally the micro-nano bubble water is prepared.

[0043] Example 1

[0044] As shown in Figure 1 , Figure 2 , Figure 3 and Figure 4 , the micro-nano bubble generating device comprises an upper part body 1, a lower part body 2 and a flow channel assembly; the flow channel assembly in example 1 is composed of circular gaskets 3 uniformly distributed in the circumference between the upper part body 1 and the lower part body 2; the upper part body 1 and the lower part body 2 are connected by bolts 10, and the upper and lower surfaces of the upper part body 1 and the lower part body 2 are smooth and flat; the liquid inlet flow channel 5 is arranged on the axis of the upper part body 1 and penetrates the entire upper part body; the gas inlet flow channel 7 is also arranged beside the liquid inlet flow channel 5, and the gas inlet flow channel 7 is in the shape of L as a whole, the lower half of the gas inlet flow channel 7 is parallel to the liquid inlet flow channel 5 and penetrates the bottom of the upper part body, the upper half of the gas inlet flow channel 7 is connected with the lower half of the gas inlet flow channel 7 perpendicularly and penetrates the side of the upper part body, the gas inlet 6 is arranged on the side of the upper part body, the gas inlet 6 is coaxial with the upper half of the gas inlet flow channel and is located at the starting end of the upper half of the gas inlet flow channel; the inscribed circle between the circular gaskets 3 uniformly distributed in the circumference forms the turbulent cavity 8, and the cavities between adjacent circular gaskets form the mixed liquid outlet 9. The gaskets 3 pass through the bolts 10, and the gaskets 3 are installed between the upper part body 1 and the lower part body 2 by the bolts 10.

[0045] In Example 1, the length L1 of the micro / nano bubble generator is 50–80 mm, the diameter d1 is 35–50 mm, and the length-to-diameter ratio L1 / d1 ranges from 1.4 to 1.6. The length L11 of the upper main body 1 is 28–40 mm. The ratio d2:d1 of the diameter of the liquid inlet 4 to the diameter of the micro / nano bubble generator ranges from 1 / 3 to 1 / 2. The ratio d3:d2 of the diameter of the gas inlet 6 to the diameter of the liquid inlet 4 ranges from 1 / 3 to 1 / 2. The ratio L3:d2 of the length of the liquid inlet and the ratio L4:d3 of the length of the gas inlet are the same, both being 1.0–1.5. The ratio L6:d3 of the distance from the center of the gas inlet 6 to the bottom of the upper main body is 1.5. The length-to-diameter ratio of the liquid inlet channel 5 is not less than 10.

[0046] To ensure high-speed flow of liquid in inlet channel 5 and small initial particle size of bubbles formed after gas intake, the diameter d21 of inlet channel 5 is 2.0 to 3.0 mm, the ratio of the diameter of inlet channel 7 to the diameter of inlet channel 5, d31:d21, is in the range of 0.6 to 0.75, and the distance L7 between the central axis of inlet channel 7 and inlet channel 5 is 1.5 to 2.5 mm.

[0047] The radius of the evenly distributed gasket 3 determines the planar area of ​​the turbulent cavity. To ensure that the turbulent cavity has a sufficient area and that the bubbles obtain a sufficient degree of turbulent breakup, the radius L5 of the evenly distributed gasket 3 is 1 / 3 of the device diameter d1, that is, L5 = d1 * 1 / 3.

[0048] like Figure 5 As shown, the thickness of the gasket 3 determines the form of the turbulence cavity 8 and the thickness L21 of the turbulence cavity 8. The thickness L21 of the turbulence cavity 8 is one of the key parameters for the device to generate micro-nano bubbles. If the thickness L21 of the turbulence cavity is too small, the pressure inside the cavity will be too high, the gas self-absorption capacity will be weakened, and the mixture will flow out along the inlet air channel. If the thickness L21 of the turbulence cavity is too large, the turbulence intensity of the mixture inside the cavity will be greatly weakened, the degree of bubble turbulence breakup will be insufficient, and the bubble particle size will be large. Through experiments, the thickness L21 of the turbulence cavity is determined to be in the range of 0.2 to 0.5 mm.

[0049] In Example 1, the gasket 3 consists of four annular rigid thin sheets. The thickness L2 of the gasket 3 is equal to the thickness L21 of the turbulence cavity 8, i.e., L2 = L21.

[0050] Example 2

[0051] Based on Example 1, the flow channel assembly is a flow channel type gasket, such as... Figure 6 and Figure 7As shown, the flow channel gasket has grooves on its surface, which are connected to the liquid inlet channel 5 and the air inlet channel 7 to form a turbulent cavity 8. Each groove has at least one gradually expanding opening to form a mixed liquid outlet 9. The thickness L2 of the flow channel gasket is 1.5–2.0 mm. The gas-liquid mixture flows into the turbulent cavity 8 along the fixed flow channel on the intermediate gasket 3, and after being broken up by turbulence, forms tiny bubbles that flow out of the device along the mixed liquid outlet 9. The groove of the flow channel gasket can be a single groove or multiple grooves of different shapes connected together; the grooves are connected to the outlets of the liquid inlet channel 5 and the air inlet channel 7, respectively.

[0052] Example 3

[0053] like Figure 8 As shown, one end of the upper main body 1 and one end of the lower main body 2 are respectively provided with a liquid inlet channel 5 and a gas inlet channel 7; the upper main body 1 and the lower main body 2 are symmetrically connected. In this case, the micro / nano bubble generator adopts a bidirectional liquid inlet type, and the micro / nano bubble generation rate of the bidirectional liquid inlet is higher than that of the unidirectional liquid inlet device in Example 1. Furthermore, the medium in the liquid inlet channel 5 at one end of the upper main body 1 is not only a single-phase liquid flow, but can also be a gas-liquid two-phase mixed flow, thus increasing the bubble content in the water.

[0054] Tests showed that the operating pressure of the micro / nano bubble generator was between 0.2 and 0.6 MPa, and the liquid flow rate was between 0.15 and 0.6 m³ / s. 3 / h, the air intake rate is 0.5 to 1% of the liquid flow rate.

[0055] like Figure 9 As shown, the micro / nano bubble generator operates at a water temperature of 27°C, an initial dissolved oxygen level of 7.15 mg / L, a working pressure of 0.3 MPa, and a water flow rate of 0.2 m³ / h. 3 The device was run for 2 minutes at an air intake rate of 15 ml / min, and the dissolved oxygen concentration was increased over time as a function of the device's operating time. The curves also showed a decrease in dissolved oxygen concentration over time after the device stopped operating. The curves indicate that when the device ran for 2 minutes, the dissolved oxygen concentration in the water rapidly increased to 8.53 mg / L, exceeding the saturated dissolved oxygen concentration of 7.96 mg / L at this temperature, indicating a supersaturated state. After the device stopped operating, the dissolved oxygen concentration in the water first rapidly decreased to 8.22 mg / L, and then fluctuated downwards due to the continuous self-pressurization and dissolution of microbubbles in the water. After standing for 8 minutes, the dissolved oxygen concentration in the water was 8.05 mg / L, still higher than the saturated dissolved oxygen concentration at this temperature.

[0056] like Figure 10As shown, the figure is a comparison chart of the bubble particles generated by the device and the prior art, wherein figure (a) is a chart of the bubble particles generated by the prior art, and figure (b) is a chart of the bubble particles generated by the device; through the intuitive comparison of the images, it can be seen that, compared with the prior art air entraining technology, the device can generate more bubble particles, the bubble particle size is smaller, and the bubble duration is longer under the same operating condition, which indicates that the device has better bubble breaking effect.

[0057] It should be understood that, although the present specification is described in terms of various embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

[0058] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present application, and are not used to limit the protection scope of the present application, and any equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A micro-nano bubble generating device, characterized by, Including upper part body (1), lower part body (2) and flow channel assembly;At least one end of the upper part body (1) or lower part body (2) is respectively provided with liquid inlet flow channel (5) and air inlet flow channel (7); The upper part body (1) and the lower part body (2) are connected by the flow channel assembly to form at least a turbulent flow cavity (8) and a mixed liquid outlet (9) in communication with each other;The turbulent flow cavity (8) is respectively communicated with the outlet of the liquid inlet flow channel (5) and the outlet of the air inlet flow channel (7), and the negative pressure generated by the liquid pressurization into the turbulent flow cavity (8) makes the gas be sucked into the turbulent flow cavity (8);The mixed liquid outlet (9) is used for outputting micro-nano bubbles; The flow channel assembly is composed of a plurality of gaskets (3), and the plurality of gaskets (3) are installed between the upper part body (1) and the lower part body (2);The flow channel assembly is a flow channel gasket, the surface of the flow channel gasket is provided with a groove, the groove is respectively communicated with the liquid inlet flow channel (5) and the air inlet flow channel (7), and is used for forming the turbulent flow cavity (8);At least one gradually expanding opening is arranged on the groove, and the mixed liquid outlet (9) is formed. 2.The micro-nano bubble generating apparatus according to claim 1, wherein The ratio of the length to the diameter of the liquid inlet flow channel (5) is not less than 10;The ratio of the diameter of the air inlet flow channel (7) to the diameter of the liquid inlet flow channel (5) is 0.6-0.

75. 3.The micro-nano bubble generating apparatus according to claim 1, wherein The distance between the center axis of the air inlet flow channel (7) and the center axis of the liquid inlet flow channel (5) is not more than 2.5 mm. 4.The micro-nano bubble generating apparatus according to claim 1, wherein The thickness of the turbulent flow cavity (8) is 0.2-0.5 mm. 5.The micro-nano bubble generating apparatus according to claim 1, wherein The gas inlet (6) of the air inlet flow channel (7) is connected with a gas flow meter, which is used for detecting the suction amount of gas. 6.The micro-nano bubble generating device according to any one of claims 1-5, characterized in that, The diameter of the liquid inlet flow channel (5) is 2.0-3.0 mm;The diameter of the air inlet flow channel (7) is 1.0-1.5 mm. 7.The micro-nano bubble generating device according to any one of claims 1-5, characterized in that, One end of the upper part body (1) and one end of the lower part body (2) are respectively provided with liquid inlet flow channel (5) and air inlet flow channel (7);The one end of the upper part body (1) and the one end of the lower part body (2) are symmetrically connected.

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