A self-priming micro-nano bubble generating device and generating method

Abstract

The present invention discloses a self-priming micro-nano bubble generator and method, belonging to the technical field of bubble generators. The method addresses at least one of the following issues: the inability of existing nanobubble generators to be applied to water containing a high concentration of impurities and the high cost associated with the pressure required to force gas into the suction chamber. The device comprises a micro-nano bubble generator, which is a tubular structure comprising a water inlet pipe, a first injection pipe, a first mixing pipe, and an outflow pipe, connected in sequence along the direction of liquid flow. The first mixing pipe is connected to the atmosphere via an air inlet pipe. The present invention can be used to generate micro-nano bubbles.

Description

Technical Field

[0001] The present invention belongs to the technical field of bubble generating devices, and in particular relates to a self-priming micro-nano bubble generating device and a generating method. Background Art

[0002] Compared with macroscopic bubbles, micro-nano bubbles have excellent adsorption properties and longer residence time. They play an important role in many fields and show great application potential.

[0003] Common methods for generating micro-nano bubbles include electrolysis, ultrasonic treatment, pressurized dissolution and jet shearing.

[0004] Chinese utility model patent CN 209549194 U discloses a high-flow nanobubble generating device with post-pump air intake, which is composed of a pressurized jet component, a jet release component, a protrusion collision flow component, and an atomization component. However, it involves multiple components with small apertures, such as jet injection ports and flow holes, which are prone to clogging in relatively harsh water environments (i.e., water with a large amount of impurities).

[0005] Chinese invention patent application CN107915326A discloses a jet-based microbubble generation method and a jet microbubble aerator. However, during the air intake process, the gas needs to pass through a certain pressure to enter the air intake chamber through the air intake pipe, and cannot be self-priming, resulting in high costs for industrial applications. Summary of the Invention

[0006] In view of the above analysis, the present invention aims to provide a self-priming micro-nano bubble generating device and generating method to solve at least one of the problems in the prior art that the nano bubble generating device cannot be applied to situations where there are many impurities in the water and that the gas requires pressure to enter the suction chamber, resulting in high cost.

[0007] The purpose of the present invention is mainly achieved through the following technical solutions.

[0008] The present invention provides a self-priming micro-nano bubble generating device including a micro-nano bubble generator. The micro-nano bubble generator is a tubular structure. The micro-nano bubble generator includes a water inlet pipe, a first injection pipe, a first mixing pipe and an outflow pipe connected in sequence along the direction of liquid flow. The first mixing pipe is connected to the atmosphere through an air inlet pipe.

[0009] Furthermore, the water inlet pipe, the first mixing pipe and the outflow pipe are constant diameter pipes, and the first injection pipe is a reduced diameter pipe.

[0010] Furthermore, the gas-liquid ratio in the micro-nano bubble generator is 0.005-0.3.

[0011] Furthermore, it also includes a water tank and a power pump. The water outlet of the water tank is connected to the water inlet end of the water inlet pipe through the power pump, and the water outlet of the outflow pipe is connected to the water inlet of the water tank. The water tank, power pump and micro-nano bubble generator form a circulation loop.

[0012] Furthermore, the power pump is one of a centrifugal pump, a peristaltic pump, a plunger pump or a slurry pump.

[0013] Furthermore, an inlet valve is provided on the pipeline connecting the water tank and the power pump;

[0014] And / or, an outlet valve is provided on the connecting pipeline between the outflow pipe and the water tank.

[0015] Furthermore, the contraction angle of the first injection pipe and the second injection pipe is 10 to 50 degrees.

[0016] Furthermore, the cross-sectional area of ​​the water inlet of the first mixing pipe is larger than the cross-sectional area of ​​the water outlet of the first injection pipe.

[0017] Furthermore, the ratio of the cross-sectional area of ​​the water inlet of the first mixing pipe to the cross-sectional area of ​​the water outlet of the first injection pipe is 1.2-4.

[0018] The present invention also provides a self-priming micro-nano bubble generating method, which adopts the self-priming micro-nano bubble generating device.

[0019] Furthermore, the self-priming micro-nano bubble generation method includes the following steps:

[0020] Step 1: Liquid enters the micro-nano bubble generator from the water inlet pipe. After flowing through the first injection pipe, part of the liquid pressure is converted into kinetic energy to form a first liquid jet, which is conducive to forming a low-pressure area in the subsequent first mixing pipe;

[0021] Step 2: The gas is sucked into the first mixing tube from the air inlet pipe at low pressure, and the liquid and the gas are preliminarily mixed in the first mixing tube to obtain a first gas-liquid mixed fluid;

[0022] Step 3: The first gas-liquid mixed fluid is sprayed into the first diffuser, and the bubbles in the first gas-liquid mixed fluid are broken once through the Venturi effect to obtain a primary broken mixed fluid;

[0023] Step 4: The primary crushed mixed fluid flows into the second injection pipe, which pressurizes and accelerates the primary crushed mixed fluid and performs secondary crushing on the bubbles in the primary crushed mixed fluid to obtain a secondary crushed mixed fluid;

[0024] Step 5: The secondary crushed mixed fluid is sprayed into the second mixing tube to generate a cavitation effect. The turbulent element in the second mixing tube crushes the bubbles in the secondary crushed mixed fluid for a third time and fully mixes the bubbles and liquid to obtain a tertiary crushed mixed fluid.

[0025] Step 6: The tertiary crushed mixed fluid flows into the second diffuser, and the large bubbles and micro-nano bubbles that are not fully crushed in the tertiary crushed mixed fluid are crushed four times by the Venturi effect to obtain a four-time crushed mixed fluid;

[0026] Step 7: The mixed fluid after the four crushing steps flows out of the micro-nano bubble generator through the outflow tube.

[0027] Furthermore, in the above step 2, the diameter of the bubbles in the first gas-liquid mixed fluid is 1 to 5 mm.

[0028] Furthermore, in the above step 3, the diameter of the bubbles in the mixed fluid that are broken at one time is 1 to 2 mm.

[0029] Furthermore, in the above step 4, the diameter of the bubbles in the secondary crushed mixed fluid is 1 to 1000 μm.

[0030] Furthermore, in the above step 5, the diameter of the bubbles in the mixed fluid after the three-time crushing is 500 to 3000 nm.

[0031] Furthermore, in the above step 6, the diameter of the bubbles in the mixed fluid after four crushing is 500-1000 nm.

[0032] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects.

[0033] A) The self-priming micro-nano bubble generating device provided by the present invention has an overall tubular structure and does not involve components with smaller apertures such as jet injection ports and flow holes. Therefore, clogging will basically not occur and it can be applied to conditions with relatively harsh water environments.

[0034] B) The self-priming micro-nano bubble generating device provided by the present invention, due to the arrangement of the first injection tube and the first mixing tube, facilitates the formation of a low-pressure zone in the subsequent first mixing tube after the liquid flows through the first injection tube. The low pressure draws the gas from the air inlet pipe into the first mixing tube, achieving self-priming of the gas through the low pressure, providing an air source for the micro-nano bubble generating device, thereby effectively reducing the production cost of nano bubbles.

[0035] C) The self-priming micro-nano bubble generating device provided by the present invention comprises a first diffuser, a second injection tube, a second mixing tube, and a second diffuser, which can break up the gas-liquid mixed fluid multiple times. Through the coupling of jet flow, cavitation, and turbulent shear, the bubble size is effectively reduced to meet the micro-nano bubble standard (high concentration and small particle size), thereby achieving stable and efficient generation of micro-nano bubbles.

[0036] D) The self-priming micro-nano bubble generation method provided by the present invention facilitates the formation of a low-pressure zone in the subsequent first mixing tube after the liquid flows through the first injection tube. The low pressure enables self-priming of the gas, providing an air source for the micro-nano bubble generation device, thereby effectively reducing the production cost of nanobubbles. In addition, the gas-liquid mixed fluid is repeatedly broken up, and the bubble size is effectively reduced to meet the micro-nano bubble standard (high concentration and small particle size) through the coupling effect of jet flow, cavitation and turbulent shear, thereby achieving stable and efficient generation of micro-nano bubbles.

[0037] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages will become apparent from the description or be understood through practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the embodiments of the description and the contents particularly pointed out in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0039] Figure 1 This is a schematic structural diagram of a self-priming micro-nano bubble generating device provided in Example 1 of the present invention;

[0040] Figure 2 This is a structural schematic diagram of the micro-nano bubble generator in the self-priming micro-nano bubble generating device provided in Example 1 of the present invention.

[0041] Reference numerals:

[0042] 1-water tank; 2-outlet valve; 3-micro-nano bubble generator; 30-water inlet pipe; 31-first injection pipe; 32-air inlet pipe; 33-first mixing pipe; 34-first diffusion pipe; 35-second injection pipe; 36-second mixing pipe; 37-turbulent element; 38-outlet pipe; 39-second diffusion pipe; 4-power pump; 5-inlet valve. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0044] Example 1

[0045] This embodiment provides a self-priming micro-nano bubble generating device, see Figure 1 , including a micro-nano bubble generator 3, the micro-nano bubble generator 3 is a tubular structure, see Figure 2 , including an inlet pipe 30, a first injection pipe 31, a first mixing pipe 33, a first diffusion pipe 34, a second injection pipe 35, a second mixing pipe 36, a second diffusion pipe 39 and an outflow pipe 38 connected in sequence along the direction of liquid flow. The first mixing pipe 33 is connected to the atmosphere through an air inlet pipe 32, and a turbulent element 37 is provided in the second mixing pipe 36 along the direction of liquid flow.

[0046] It should be noted that the first injection pipe 31 and the second injection pipe 35 are reduced diameter pipes, the first diffusion pipe 34 and the second diffusion pipe 39 are expanded diameter pipes, and the water inlet pipe 30, the first mixing pipe 33, the second mixing pipe 36 and the outflow pipe 38 are constant diameter pipes.

[0047] During implementation, the liquid enters the micro-nano bubble generator 3 from the water inlet pipe 30. After the liquid flows through the first injection pipe 31, part of the pressure of the liquid is converted into kinetic energy to form a first liquid jet, which is conducive to forming a low-pressure area in the subsequent first mixing pipe 33; the gas is sucked into the first mixing pipe 33 from the air inlet pipe 32 through the low pressure, and the liquid and gas are preliminarily mixed in the first mixing pipe 33 to obtain a first gas-liquid mixed fluid; the first gas-liquid mixed fluid is sprayed to the first diffuser 34, and the bubbles in the first gas-liquid mixed fluid are broken once through the Venturi effect to obtain a primary broken mixed fluid; the primary broken mixed fluid flows into the second injection pipe 35, and the second injection pipe 35 performs a secondary induced ... The pressure is increased and accelerated, and the bubbles in the primary broken mixed fluid are broken for a second time to obtain a secondary broken mixed fluid; the secondary broken mixed fluid is sprayed into the second mixing tube 36 to generate a cavitation effect, and the turbulent element in the second mixing tube 36 breaks the bubbles in the secondary broken mixed fluid for a third time and fully mixes the bubbles and liquid to obtain a tertiary broken mixed fluid; the tertiary broken mixed fluid flows into the second diffuser 39, and the large bubbles and micro-nano bubbles that are not fully broken in the tertiary broken mixed fluid are broken for a fourth time through the Venturi effect to obtain a quaternary broken mixed fluid; the quaternary broken mixed fluid flows out of the micro-nano bubble generator 3 through the outflow tube 38 to obtain a fluid containing both micro-nano bubbles and millimeter bubbles.

[0048] It should be noted that the solution adopted in this embodiment is to first blow in larger bubbles through the air inlet pipe 32 and then break them up multiple times to obtain a fluid containing both micro-nano bubbles and millimeter bubbles.

[0049] Compared with the prior art, the self-priming micro-nano bubble generating device provided in this embodiment has the following characteristics: on the one hand, the micro-nano bubble generator 3 is a tubular structure as a whole, and does not involve components with smaller apertures such as jet injection ports and flow holes. Therefore, basically no clogging will occur, and it can be applied to relatively harsh water environments; on the other hand, due to the arrangement of the first injection pipe 31 and the first mixing pipe 33, after the liquid flows through the first injection pipe 31, it is conducive to forming a low-pressure zone in the subsequent first mixing pipe 33, and the gas is sucked into the first mixing pipe 33 from the air inlet pipe 32 through the low pressure. The self-priming of the gas is achieved through the low pressure, providing an air source for the micro-nano bubble generating device, thereby effectively reducing the production cost of nano bubbles; on the other hand, the first diffuser 34, the second injection pipe 35, the second mixing pipe 36 and the second diffuser 39 can break the gas-liquid mixed fluid multiple times, and through the coupling effect of jet, cavitation and turbulent shear, the bubble size is effectively reduced to meet the micro-nano bubble standard (high concentration and small particle size), thereby achieving stable and efficient generation of micro-nano bubbles.

[0050] In order to ensure the supply of air so as to form sufficient micro-nano bubbles, the gas-liquid ratio in the micro-nano bubble generator 3 is 0.005-0.3.

[0051] Exemplarily, the flow-disturbing element 37 is one of a self-driven rotating impeller, a fixed multi-layer blade or a spiral blade.

[0052] Specifically, the structure of the self-driven rotating impeller includes a radial support rod, an axial support shaft, and a plurality of impellers. The radial support rod is arranged along the radial direction of the second mixing tube 36. One end of the radial support rod is fixedly connected to the side wall of the second mixing tube 36, and the other end is fixedly connected to one end of the axial support shaft. The other end of the axial support shaft is a suspended end. The plurality of impellers are sleeved on the outer wall of the axial support shaft and are rotatably connected to the outer wall of the axial support shaft. Each impeller includes a plurality of inclined blades arranged axially along the axial support shaft. For example, the number of inclined blades is 2 to 4. In this way, by the fluid impacting the inclined blades, the power of the fluid can be used to drive the impeller to rotate, thereby realizing the unpowered rotation of the self-driven rotating impeller.

[0053] Exemplarily, the shape of the radial support rod may be a straight line, a herringbone shape or a cross shape.

[0054] As for the structure of the spiral blades, for example, to facilitate the introduction of fluid into the turbulence element 37, the spiral blades include a guide plate, a guide vane, and a plurality of agitation vanes, sequentially connected along the fluid flow direction. The guide plate is a flat plate disposed axially along the second mixing tube 36, and the helical angle of the guide vane is greater than that of the agitation vane. In this way, the fluid can be guided into the guide vane via the guide plate, initially agitated there, and then further agitated by the agitation vane, thereby reducing resistance to the fluid flow.

[0055] It can be understood that in order to provide liquid for the micro-nano bubble generator 3, the above-mentioned self-priming micro-nano bubble generating device also includes a water tank 1 and a power pump 4. The water outlet of the water tank 1 is connected to the water inlet end of the water inlet pipe 30 through the power pump 4, and the water outlet of the outflow pipe 38 is connected to the water inlet of the water tank 1. The water tank 1, the power pump 4 and the micro-nano bubble generator 3 constitute a circulation loop. The water in the water tank 1 is pressurized by the power pump 4 and supplied to the water inlet pipe 30 as the liquid source of the micro-nano bubble generator 3.

[0056] It should be noted that since the above-mentioned micro-nano bubble generator 3 is a tubular structure with a large inner diameter, the power pump 4 only needs to provide less pressure to achieve the supply and flow of liquid. For example, the outlet pressure of the power pump 4 is not less than 0.25 MPa (for example, 0.25~0.75 MPa); thereby further reducing the energy consumption of the above-mentioned self-priming micro-nano bubble generating device and reducing production costs.

[0057] Exemplarily, the power pump 4 is one of a centrifugal pump, a peristaltic pump, a plunger pump or a slurry pump.

[0058] In order to achieve automatic control of the above-mentioned self-priming micro-nano bubble generating device, an inlet valve 5 is provided on the pipeline connecting the above-mentioned water tank 1 and the power pump 4, and / or an outlet valve 2 is provided on the connecting pipeline between the above-mentioned outflow pipe 38 and the water tank 1. In this way, the inlet valve 5 can control the on-off between the water tank 1 and the power pump 4, thereby realizing automatic control of the water supply to the water tank 1, and the outlet valve 2 can realize the on-off between the micro-nano bubble generator 3 and the water tank 1, thereby realizing the on-off supply of micro-nano bubbles.

[0059] To enhance the jet effect, the contraction angle of the first and second jet pipes 31, 35 is set between 10 and 50 degrees. Accordingly, the flow velocity at the outlet of the first jet pipe 31 is between 5 and 10 m / s, while the flow velocity at the second jet pipe 35 is between 10 and 30 m / s. By limiting the contraction angle to this range, the fluid pressure can be minimized while maintaining the jet effect, thereby reducing the pressure required by the power pump 4 and the production cost.

[0060] Likewise, in order to enhance the Venturi effect, the diffusion angles of the first diffuser 34 and the second diffuser 39 are 6 to 60 degrees.

[0061] It is worth noting that the sizes of the first injection pipe 31 and the first mixing pipe 33 will directly affect the self-priming effect. In order to improve the self-priming efficiency of the air and ensure that sufficient air is supplied to the first mixing pipe 33, the cross-sectional area of ​​the water inlet of the above-mentioned first mixing pipe 33 is larger than the cross-sectional area of ​​the water outlet of the first injection pipe 31. Exemplarily, the ratio of the cross-sectional area of ​​the water inlet of the first mixing pipe 33 to the cross-sectional area of ​​the water outlet of the first injection pipe 31 is 1.2 to 4.

[0062] Accordingly, in order to improve the injection effect of the second injection pipe 35, the cross-sectional area of ​​the water inlet of the above-mentioned second mixing pipe 36 is larger than the cross-sectional area of ​​the water outlet of the second injection pipe 35. For example, the ratio of the cross-sectional area of ​​the water inlet of the second mixing pipe 36 to the cross-sectional area of ​​the water outlet of the second injection pipe 35 is 1.2 to 4.

[0063] For the description of the above cross-sectional area, Figure 2 It can be seen that the connection between the first injection pipe 31 and the first mixing pipe 33 is not a continuous section, but a step. Similarly, the connection between the second injection pipe 35 and the second mixing pipe 36 is not a continuous section, but a step.

[0064] Example 2

[0065] This embodiment provides a method for generating self-priming micro-nano bubbles, which includes the following steps:

[0066] Step 1: Liquid enters the micro-nano bubble generator from the water inlet pipe. After flowing through the first injection pipe, part of the liquid pressure is converted into kinetic energy to form a first liquid jet, which is conducive to forming a low-pressure area in the subsequent first mixing pipe;

[0067] Step 2: The gas is sucked into the first mixing tube from the air inlet pipe at low pressure, and the liquid and gas are preliminarily mixed in the first mixing tube to obtain a first gas-liquid mixed fluid. At this time, the gas exists in the form of large bubbles with a diameter of 1 to 5 mm.

[0068] Step 3: The first gas-liquid mixed fluid is sprayed into the first diffuser, and the bubbles in the first gas-liquid mixed fluid are broken once by the Venturi effect to obtain a primary broken mixed fluid, in which large bubbles are broken into small bubbles with a diameter of 1 to 2 mm.

[0069] Step 4: The primary crushed mixed fluid flows into the second injection pipe, which pressurizes and accelerates the primary crushed mixed fluid and performs secondary crushing on the bubbles in the primary crushed mixed fluid to obtain a secondary crushed mixed fluid. The small bubbles are crushed into microbubbles with a diameter of 1 to 1000 μm.

[0070] Step 5: The secondary crushed mixed fluid is sprayed into the second mixing tube to generate a cavitation effect. The turbulent element in the second mixing tube crushes the bubbles in the secondary crushed mixed fluid for a third time and fully mixes the bubbles and liquid to obtain a tertiary crushed mixed fluid. The microbubbles are crushed into micro-nanobubbles with a diameter of 500 to 3000 nm.

[0071] Step 6: The tertiary crushed mixed fluid flows into the second diffuser, and the large bubbles and micro-nano bubbles that are not fully crushed in the tertiary crushed mixed fluid are crushed four times by the Venturi effect to obtain a four-time crushed mixed fluid. The bubbles mainly exist in the form of micro-nano bubbles with a diameter of 500-1000 nm.

[0072] Step 7: The mixed fluid after the four crushing steps flows out of the micro-nano bubble generator through the outflow tube.

[0073] Compared with the prior art, the self-priming micro-nano bubble generation method provided in this embodiment is conducive to forming a low-pressure zone in the subsequent first mixing tube after the liquid flows through the first injection tube, and realizes self-priming of the gas through the low pressure, providing an air source for the micro-nano bubble generation device, thereby effectively reducing the production cost of nano bubbles; in addition, the gas-liquid mixed fluid is broken multiple times, and the bubble size is effectively reduced through the coupling effect of jet, cavitation and turbulent shear, so that it meets the micro-nano bubble standard (high concentration and small particle size), thereby realizing stable and efficient generation of micro-nano bubbles.

[0074] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A self-priming micro-nano bubble generating device, characterized in that: The micro-nano bubble generator is a tubular structure comprising an inlet pipe, a first injection pipe, a first mixing pipe, a first diffusion pipe, a second injection pipe, a second mixing pipe, a second diffusion pipe, and an outlet pipe, which are sequentially connected along the direction of liquid flow. The first mixing pipe is connected to the atmosphere through an air inlet pipe, and a flow-disturbing element is provided in the second mixing pipe along the direction of liquid flow. The first injection pipe and the second injection pipe are reduced diameter pipes, the first diffusion pipe and the second diffusion pipe are expanded diameter pipes, and the water inlet pipe, the first mixing pipe, the second mixing pipe and the outflow pipe are constant diameter pipes; The diffusion angles of the first diffusion tube and the second diffusion tube are 6 to 60 degrees; The gas-liquid ratio in the micro-nano bubble generator is 0.005-0.3; The contraction angle of the first injection pipe and the second injection pipe is 10-50°; The ratio of the cross-sectional area of ​​the water inlet of the first mixing pipe to the cross-sectional area of ​​the water outlet of the first injection pipe is 1.2-4.

2. The self-priming micro-nano bubble generating device according to claim 1, characterized in that It also includes a water tank and a power pump. The water outlet of the water tank is connected to the water inlet end of the water inlet pipe through the power pump, and the water outlet of the outflow pipe is connected to the water inlet of the water tank. The water tank, power pump and micro-nano bubble generator form a circulation loop.

3. The self-priming micro-nano bubble generating device according to claim 2, characterized in that: The power pump is one of a centrifugal pump, a peristaltic pump, a plunger pump or a slurry pump.

4. The self-priming micro-nano bubble generating device according to claim 2, characterized in that: An inlet valve is provided on the pipeline connecting the water tank and the power pump; And / or, an outlet valve is provided on the connecting pipeline between the outflow pipe and the water tank.

5. A self-priming micro-nano bubble generation method, characterized in that: A self-priming micro-nano bubble generating device as described in any one of claims 1 to 4 is used.

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