CN-121972038-A - Particle size controllable micro-nano bubble generation device and regulation and control method

CN121972038ACN 121972038 ACN121972038 ACN 121972038ACN-121972038-A

Abstract

The invention discloses a micro-nano bubble generation device with controllable particle size and a regulating and controlling method. The initial bubble generation assembly comprises a gas cylinder (1), a liquid tank (2), a gas-liquid mixing valve (3), a bubble generation core unit (4) and a bubble homogenizing mixer (5), and the bubble refining dispersion assembly comprises an electric telescopic table (6), an ultrasonic signal generator (7), a signal amplifier (8), an ultrasonic generating probe (9) and a water storage tank (10) for accommodating micro-nano bubble dispersion systems. The initial micro-nano bubbles are generated by utilizing a bubble generation core unit (4), then the primary bubbles are generated under the action of sound field standing waves based on Helmholtz resonance effect through an ultrasonic radiation generation probe (9) arranged above a gas-liquid interface, and the primary bubbles are broken into sub-bubbles with smaller particle sizes through an acoustic cracking mechanism, so that the accurate control of the particle sizes of the bubbles is realized.

Inventors

LI GANG
JIANG BOYANG
XU XIUPING
HAN JIAWANG
YANG YING

Assignees

中钢集团马鞍山矿山研究总院股份有限公司
山东科技大学

Dates

Publication Date: 20260505
Application Date: 20260205

Claims (10)

1. The micro-nano bubble generating device with controllable particle size is characterized by comprising an initial bubble generating assembly and a bubble refining and dispersing assembly; The initial bubble generation assembly comprises a gas cylinder (1), a liquid tank (2), a gas-liquid mixing valve (3), a bubble generation core unit (4) and a bubble homogenizing mixer (5), wherein the gas cylinder (1) and the liquid tank (2) are respectively connected with the gas-liquid mixing valve (3) through connecting pipelines, the gas-liquid mixing valve (3) is connected with the bubble generation core unit (4) through a gas-liquid conveying pipeline, the bubble generation core unit (4) is connected with the bubble homogenizing mixer (5) through a bubble conveying pipeline, and spiral blades (11) are arranged in the bubble homogenizing mixer (5); The bubble refining and dispersing assembly comprises an electric telescopic table (6), an ultrasonic signal generator (7), a signal amplifier (8), an ultrasonic generating probe (9) and a water storage tank (10) for containing micro-nano bubble dispersion systems, wherein the electric telescopic table (6) is respectively arranged on a top plate and a bottom plate of a tank body of the water storage tank (10), the ultrasonic generating probe (9) is vertically arranged above a gas-liquid interface of the water storage tank (10) through the electric telescopic table (6) positioned on the top plate of the tank body of the water storage tank (10), the ultrasonic signal generator (7) is connected with the ultrasonic generating probe (9) through the signal amplifier (8), the frequency range generated by the ultrasonic signal generator (7) is controlled to be 65.26 kHz-6.526 GHz, and the sound pressure is regulated to be 0.5 MPa-10 MPa by the signal amplifier (8); The outlet of the bubble homogenizing mixer (5) in the initial bubble generation assembly is connected with the inlet of the water storage tank (10) in the bubble refining dispersion assembly through a pipeline.
2. The micro-nano bubble generating device with controllable particle size according to claim 1, wherein the bubble generating core unit (4) is any one of a dissolved gas releaser corresponding to a pressure dissolved gas releasing method, a venturi tube corresponding to a hydrodynamic cavitation method, a vortex cavitation bubble breaker or a multi-stage decompression releasing structure, an electrode plate corresponding to an electrolytic method, a micro-fluidic chip or a micro-channel device corresponding to a micro-channel method and an ultrasonic vibrator transducer corresponding to an ultrasonic cavitation method.
3. The micro-nano bubble generating device with controllable particle size according to claim 1, wherein the connecting pipelines among the gas cylinder (1), the liquid tank (2) and the gas-liquid mixing valve (3) are respectively provided with a pressure reducing valve and a flowmeter for controlling the flow of gas and liquid.
4. The micro-nano bubble generating device with controllable particle size as set forth in claim 1, wherein the electric telescopic table (6) is provided with a position feedback system, and can monitor and adjust the distance H between the ultrasonic wave generating probe (9) and the liquid level in real time, so as to ensure that H is an integral multiple of half wavelength of the ultrasonic wave, and form stable sound field standing waves.
5. The micro-nano bubble generation and regulation method with controllable particle size is characterized in that the adopted micro-nano bubble generation device comprises an initial bubble generation assembly and a bubble refining and dispersing assembly; The initial bubble generation assembly comprises a gas cylinder (1), a liquid tank (2), a gas-liquid mixing valve (3), a bubble generation core unit (4) and a bubble homogenizing mixer (5), wherein the gas cylinder (1) and the liquid tank (2) are respectively connected with the gas-liquid mixing valve (3) through connecting pipelines, the gas-liquid mixing valve (3) is connected with the bubble generation core unit (4) through a gas-liquid conveying pipeline, the bubble generation core unit (4) is connected with the bubble homogenizing mixer (5) through a bubble conveying pipeline, a helical blade (11) is arranged in the bubble homogenizing mixer (5), and the bubble generation core unit (4) is any one of a dissolved gas releaser corresponding to a pressure dissolved gas releasing method, a venturi tube corresponding to a hydraulic cavitation method, an eddy cavitation bubble breaker or a multistage pressure-reducing gas releasing structure, an electrode plate corresponding to an electrolytic method, a micro-fluidic chip or a micro-channel device corresponding to a micro-channel method and an ultrasonic transducer corresponding to an ultrasonic cavitation method; The bubble refining and dispersing assembly comprises an electric telescopic table (6), an ultrasonic signal generator (7), a signal amplifier (8), an ultrasonic signal generator (9) and a water storage tank (10) for containing micro-nano bubble dispersion systems, wherein the electric telescopic table (6) is respectively arranged on the top plate and the bottom plate of the tank body of the water storage tank (10), and the ultrasonic signal generator (7) is vertically arranged above the gas-liquid interface of the water storage tank (10) through the electric telescopic table (6) positioned on the top plate of the tank body of the water storage tank (10); The outlet of the bubble homogenizing mixer (5) in the initial bubble generation assembly is connected with the inlet of the bubble refining dispersion assembly water storage tank (10) through a pipeline; the micro-nano bubble generation and regulation method comprises the following steps: S1, mixing gas and liquid The gas cylinder (1) and the liquid tank (2) respectively provide a gas source and a liquid source, and the gas source and the liquid source are mixed according to a set proportion through the gas-liquid mixing valve (3) to form mixed gas-liquid; S2, initial micro-nano bubble generation The mixed gas-liquid flows into a bubble generation core unit (4) to generate initial micro-nano bubbles; s3, initial micro-nano bubble dispersion mean value The generated initial micro-nano bubbles then flow into a bubble homogenizing mixer (5), and the uniform dispersion and stable release of the bubbles are promoted under the action of the spiral movement of a spiral blade (11), so that the coalescence of the micro-nano bubbles is avoided; s4, formation of gas-liquid dispersion system The micro-nano bubbles after the mean value is dispersed flow into a water storage tank (10) to form a micro-nano bubble gas-liquid dispersion system; S5, ultrasonic regulation and control Generating ultrasonic waves through an ultrasonic wave generating probe (9) arranged above a gas-liquid interface of a water storage tank (10), generating primary bubbles at the liquid level under the action of a sound field standing wave based on the Helmholtz resonance effect, adjusting the distance between the ultrasonic wave generating probe (9) and the liquid level, and adjusting the half wavelength of the ultrasonic waves to be integral multiple so as to form stable sound field standing waves; S6, refining particle size from sound to fracture The ultrasonic signal generator (7) is used for generating ultrasonic waves, the generated primary bubbles are broken into sub-bubbles with smaller particle sizes through the sound-induced breaking mechanism, and the accurate control of the particle sizes of the micro-nano bubbles is realized by adjusting ultrasonic parameters and the distance between the ultrasonic generating probe (9) and the liquid surface.
6. The method for generating and controlling micro-nano bubbles with controllable particle size according to claim 5, wherein in the step S6, the ultrasonic frequency generated by the ultrasonic generating probe (9) is controlled to be 65.26kHz to 6.526GHz, and the ultrasonic frequency is determined based on a Minnaert frequency formula of the micro-nano bubbles: Wherein R 0 is the equilibrium radius of micro-nano bubbles, m, gamma is the specific heat ratio of gas in the bubbles, air takes 1.4, P 0 is the environmental static pressure acting on the micro-nano bubbles, pa, ρ is the liquid density, kg/m 3 .
7. The method for generating and regulating micro-nano bubbles with controllable particle size according to claim 5, wherein in the step S6, the sound-induced cracking mechanism is a mode 1 of film outward folding, when the micro-nano bubbles are right under an ultrasonic wave generating probe (9), the bubble liquid film is quickly retracted towards the edge, and is outwards folded and pinched off under the inertia effect to form a ring-shaped sub-bubble string, the process is dominated by the inertia effect, the Reynolds number (Re) calculated value Re-10 3 > >1 shows that the inertia force is far greater than the viscous force, the folding and pinching-off actions of the liquid film are supported, and the Reynolds number expression is: Wherein ρ is the density of the liquid, kg/m 3 , R is the radius of the primary bubble, m, U is the retraction speed of the liquid film, m/s, μ is the dynamic viscosity of the liquid, pa.s.
8. The method of generating and controlling micro-nano bubbles with controllable particle size according to claim 5, wherein in the step S6, the sound-induced cracking mechanism is a mode 2 of film inward folding, when the bubble deviates from the center of the probe, the micro-nano bubbles are attracted by a sound field, the liquid film is inward folded to capture a plurality of small sub-bubbles, at this time, the sound radiation force is dominant, the sound bond number Boa calculated value Bo a >1 shows that the sound radiation force overcomes the surface tension, and the sound bond number expression is: where v rms is the root mean square value of the vibration velocity of the medium particles, m/s, and σ is the surface tension of the liquid, N/m.
9. The method of generating and controlling micro-nano bubbles with controllable particle size according to claim 5, wherein in step S5, the half wavelength of the ultrasonic wave is adjusted to be lambda/2, lambda or 3 lambda/2 to optimize the standing wave of the sound field.
10. The micro-nano bubble generation and regulation method with controllable particle size according to claim 5, wherein a pressure reducing valve and a flow meter are respectively arranged on connecting pipelines among the gas cylinder (1), the liquid tank (2) and the gas-liquid mixing valve (3) and used for controlling the flow rates of gas and liquid, the electric telescopic table (6) is provided with a position feedback system, the distance H between the ultrasonic wave generation probe (9) and the liquid level can be monitored and regulated in real time, the integral multiple of half-wavelength of ultrasonic waves is ensured, stable sound field standing waves are formed, and the sound pressure is regulated to 0.5-10 MPa by the signal amplifier (8).

Description

Particle size controllable micro-nano bubble generation device and regulation and control method Technical Field The invention belongs to the technical field of micro-nano bubble preparation, and particularly relates to a micro-nano bubble generation device with controllable particle size and a regulating and controlling method. Background The micro-nano bubble technology is used as a high-efficiency gas-liquid dispersion means, and has wide application prospect in the fields of environmental treatment, biomedicine, industrial cleaning, agricultural irrigation and the like. Micro-nano bubbles generally refer to bubbles with the particle size ranging from 1nm to 100 mu m, have the advantages of large specific surface area, long residence time, high mass transfer efficiency and the like, and can obviously enhance the gas-liquid reaction process. However, the practical application effect of micro-nano bubble technology is highly dependent on the particle size distribution and controllability of bubbles. Ideally, the micro-nano bubbles should have characteristics of small particle size, uniform distribution and adjustability so as to ensure stability, functionality and applicability. However, the existing micro-nano bubble preparation method still has the bottleneck problems of larger average particle size, wide particle size distribution, uncontrollable particle size and the like of the primary generated bubbles, and severely restricts the popularization and optimization of the technology. At present, the mainstream preparation method of micro-nano bubbles mainly comprises a pressure gas dissolving and releasing method, a hydrodynamic cavitation method, an electrolytic method, a micro-channel method, an ultrasonic cavitation method and the like. The pressure dissolved air release method is used for quickly releasing pressure to generate bubbles after high-pressure dissolved air, but the particle size of the generated bubbles is easily influenced by pressure fluctuation, so that fine regulation and control are difficult to realize, the hydrodynamic cavitation method is used for generating bubbles by utilizing fluid shearing or vortex cavitation, but the particle size of the bubbles is generally larger and has poor uniformity, the electrolytic method is used for generating the bubbles by electrochemical reaction, but the energy consumption is high and the bubble yield is limited, the microchannel method is used for preparing monodisperse bubbles based on a microfluidic technology, the equipment is complex, the cost is high and the blockage is easy, the ultrasonic cavitation method is used for generating the bubbles by initiating cavitation effect through an immersed ultrasonic probe, but the particle size of the bubbles generated by the method is limited by cavitation intensity, and the problem of pollution or abrasion can be caused by the direct contact of the probe with liquid. In addition, the methods are focused on a one-time generation process, and the defect of a subsequent refinement mechanism of generated bubbles causes uncontrollable bubble particle size, so that the requirements of different application scenes on particle size accuracy are difficult to meet. Particularly, although the existing ultrasonic cavitation method can generate micro-nano bubbles, the mechanism of the ultrasonic cavitation method depends on cavitation effect inside liquid, and the probe must be immersed in the liquid to induce cavitation. The method cannot realize active regulation and control of the particle size of the bubbles, and the generated nanocrystals can interfere with the stability of the bubbles. In contrast, the ultrasonic action mechanism introduced by the invention is quite different, namely, the ultrasonic radiation generating probe is arranged above the gas-liquid interface, and the primary generated bubbles are secondarily refined by utilizing the sound field standing wave effect and the sound induced cracking mechanism. The design not only avoids the problem caused by the contact of the probe with the liquid, but also realizes the accurate control of the particle size by adjusting the sound field parameters, and makes up the defects of the prior art. In summary, the existing micro-nano bubble generation method has significant defects in the aspect of particle size controllability, and the particle size of the primary generated bubbles is overlarge and is unevenly distributed, so that the efficiency of the micro-nano bubble technology in high-end application is affected. Therefore, development of a micro-nano bubble generation method and device which are compatible with various existing generators and can realize active regulation of bubble particle size is needed to promote uniformity and stability of bubbles and promote innovation and development of micro-nano bubble technology. Disclosure of Invention The invention aims to provide a micro-nano bubble generation device with controllable particle size, which s