CN111348711B

CN111348711B - Multistage step type venturi bubble generating device

Info

Publication number: CN111348711B
Application number: CN202010119928.7A
Authority: CN
Inventors: 王德忠; 宋煜晨; 申屠云奇; 尹俊连; 蔡康贝
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2020-02-26
Filing date: 2020-02-26
Publication date: 2021-08-31
Anticipated expiration: 2040-02-26
Also published as: CN111348711A

Abstract

The invention provides a multistage step type Venturi type bubble generating device which comprises a contraction section, a throat section, an air guide pipe and a diffusion section, wherein the diffusion section consists of multistage steps; the gas-guide tube is connected from four positions of the throat part section; the diffusion section is composed of two steps with alpha and beta inclination angles, the diffusion section of a common Venturi bubbler is divided into multiple steps, the turbulence intensity of the diffusion section of the Venturi bubbler is enhanced by inclining the angles of the two steps, and the on-way loss caused by the cavitation effect of the diffusion section can be ensured to be inhibited.

Description

Multistage step type venturi bubble generating device

Technical Field

The invention relates to the technical field of fluid dynamics, in particular to a multistage stepped venturi type bubble generating device.

Background

Microbubbles find wide application in many industrial fields, such as sewage treatment, oil and gas field drilling, medical imaging, mineral flotation, etc. The current microbubble generation methods mainly comprise three methods: air is introduced to produce bubbles, the pressure dissolved air is used for separating out bubbles, and the bubbles are separated out through electrolysis. However, these microbubble generation methods have the disadvantages of complex structure, high energy consumption, structural instability, and the like.

The bubbling degassing technology has wide application prospect in industry, wherein the Venturi type bubbler has the advantages of simple structure, strong stability and the like. For example, during the operation of fourth generation reactor molten salt reactors, large amounts of fission products are produced which affect the economics and stability of the reactor. The bubbling-degassing technology is used for removing fission gas, for example, a bypass degassing technology is proposed in research of MSBR, an independent bypass is led out through an outlet of a fuel circulating pump, and a bubbling device is adopted in a branch to continuously fill micro bubbles into the bypass to form bubble flow. Because the solubility of the radioactive gas in the molten salt is low, the radioactive gas is transferred to the bubbles through mass transfer after contacting the bubbles, and then the bubbles are separated from the molten salt and enter a tail gas treatment system, so that the aim of effectively removing fission gas is fulfilled. The bubble-degassing method is internationally believed to be the most likely solution to fission gas removal. But basic scientific problems such as micro-bubble generation, fission gas mass transfer diffusion and the like restrict the development of the bubbling-degassing technology.

The bubbling degassing technology has high utilization value in the field of chemical industry, particularly in the aspect of sewage treatment, large bubbles are crushed into micron-level bubbles based on the principle of turbulent flow fragmentation through the special design of the bubble generating device, the mass transfer process is strengthened, the absorption rate of impurities in the sewage treatment process is improved, and the energy consumption is saved.

In fluid control applications, the multistage stepped venturi bubble generation device has strong robustness and fault tolerance under various working conditions. The mechanical structure has the advantages of simple structure, no moving part, independence of a driving device and the like, and can be widely applied to the fields of nuclear power, hydraulic systems, petrochemical industry and the like.

Disclosure of Invention

In view of the defects in the prior art, the invention aims to provide a multistage stepped venturi-type bubble generating device.

The invention provides a multistage step type Venturi type bubble generating device which comprises a contraction section, a throat section, an air guide pipe and a diffusion section, wherein the contraction section is provided with a throat part;

the contraction section, the throat section and the diffusion section are sequentially connected, and the gas guide pipe is vertically connected with the throat section;

the diffusion section is composed of multistage steps, the steps are divided into two types according to the inclination angles, the two inclination angles are respectively recorded as a first inclination angle and a second inclination angle, and the steps of the first inclination angle and the steps of the second inclination angle are alternately connected to form a step shape.

Preferably, in the diffusion section, the first inclination angle is a first included angle α formed by the first step inclined edge and the throat section, the second inclination angle is a second included angle β formed by the second step inclined edge and the throat section, the multistage steps form an integral wall surface, the first step inclined edge and the second step inclined edge both form a third included angle γ, and the third included angle γ maintains a specific angle value.

Preferably, the specific angle value is 3 °.

Preferably, the integral wall surface forms a fourth angle θ with the throat section of 7.5 °, or 10 °, or 12.5 °.

Preferably, the first included angle α and the second included angle β are respectively three combinations of 4.5 ° and 10.5 °, 7 ° and 13 °, 9.5 ° and 15.5 °, and the number of steps corresponding to each combination is different.

Preferably, the inlet pipe diameter of the contraction section is the same as the length of the outlet inner pipe diameter of the diffusion section.

Preferably, the lengths of the pipe diameter of the inlet of the contraction section and the pipe diameter of the inner part of the outlet of the diffusion section are both 53 mm.

Preferably, the length of the constriction section is 37mm and the length of the throat section is 50 mm.

Preferably, the throat section extends through four inlet apertures. The diameter of the air inlet hole is 1 mm.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention divides the diffusion section of the common Venturi bubbler into a plurality of steps, enhances the turbulence intensity of the diffusion section of the Venturi bubbler by inclining the angles of the two steps, simultaneously can ensure the on-way loss caused by the cavitation effect of the diffusion section, has simple structure and strong stability, also improves the efficiency of breaking bubbles at the diffusion section, simultaneously reduces the energy consumption, solves the problem of the scale of the bubble generated by the Venturi bubbler, and provides technical support for sewage purification in the chemical field and fission gas separation in the nuclear engineering field.

2. The step-type structure of the diffusion section can lead the millimeter-level large bubbles to be crushed into micron-level small bubbles by a fluid dynamics control method based on the principle of turbulent flow crushing.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic cross-sectional view of the present invention;

FIG. 2 is a schematic view of the step local angle setting of the present invention;

FIG. 3 is a schematic diagram of the overall three-dimensional structure of the present invention;

fig. 4 is a schematic diagram of an embodiment of the present invention.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

As shown in fig. 1, the multistage stepped venturi-type bubble generating device of the present invention includes a contraction section, a throat section, an air duct, and a diffusion section, wherein the contraction section is denoted by C in the drawing, the throat section is denoted by T in the drawing, and the diffusion section is denoted by D in the drawing;

the contraction section, the throat section and the diffusion section are sequentially connected, the multi-stage step design structure is located in the diffusion section, and the gas guide pipe is vertically connected with the throat section.

The steps of the diffusion section are divided into two types according to the inclination angles, the two inclination angles are respectively recorded as a first inclination angle and a second inclination angle, and the steps of the first inclination angle and the steps of the second inclination angle are alternately connected to form a step shape.

As shown in fig. 2 and 4, the first inclination angle is a first included angle α formed by the first step inclined edge D _ α 1 and the edge T of the throat section, the second inclination angle is a second included angle β formed by the second step inclined edge D _ β 1 and the edge T of the throat section, the multiple steps form an integral wall surface, and the integral wall surface forms a third included angle γ with both the first step inclined edge D _ α 1 and the second step inclined edge D _ β 1, and is always maintained at 3 °.

Various combinations of the second inclination angle and the second inclination angle exist, and the first included angle alpha and the second included angle beta can be three combinations of 4.5 degrees and 10.5 degrees, 7 degrees and 13 degrees, 9.5 degrees and 15.5 degrees respectively, so that the structures of the diffusion sections with different step numbers are corresponded. The diffusion section consists of a plurality of steps, the diffusion section comprises N steps, the integral wall surface is also the integral boundary set of all the steps, and a fourth included angle theta formed by the integral wall surface and the throat section is 7.5 degrees, 10 degrees or 12.5 degrees.

The inlet pipe diameter of the contraction section and the inside pipe diameter of the outlet of the diffusion section are both 53mm, and the inside pipe diameter of the throat section is 23 mm. The length of the throat section is 50mm, and the length of the contraction section is 37 mm.

As shown in FIG. 3, the throat section penetrates four air inlet holes from four directions, and the diameter of each air inlet hole is 1 mm.

In the specific implementation process, the diffuser section consists of multistage steps, the air guide pipes are connected from four positions of the throat part, the air guide pipes are also called branch air pipes, and the diffuser section is also called a venturi tube diffuser section. The two different inclination angles of the diffusion section are alpha and beta, the angle alpha is 4.5 degrees and is the included angle between D _ alpha 1 and the side T of the throat section, the angle beta is 10.5 degrees and is the included angle between D _ beta 1 and the side T of the throat section, and the angle gamma is the included angle between the integral wall surface and D _ alpha and D _ beta respectively and is always kept at 3 degrees. The diffuser section consists of a plurality of steps, the diffuser section comprises steps with the number N being 7, and the integral boundary set of all the steps forms an included angle theta of 7.5 degrees with the throat section. The inlet pipe diameter of the contraction section and the inside pipe diameter of the outlet of the diffusion section are both 53mm, and the inside pipe diameter of the throat section is 23 mm. The length of the throat section is 50mm, and the length of the contraction section is 37 mm. The throat section penetrates through the four air inlet holes. The diameter of the air inlet hole is 1 mm. The two different inclination angles α and β may be 4.5 ° and 10.5 °, respectively, thereby corresponding to the configuration of the diffuser section with different numbers of steps.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.

Claims

1. A multi-step Venturi type bubble generating device is characterized by comprising a contraction section, a throat section, an air duct and a diffusion section;

the diffusion section consists of a plurality of stages of steps, the steps are divided into two types according to the inclination angles, the two inclination angles are respectively marked as a first inclination angle and a second inclination angle, and the steps with the first inclination angle and the steps with the second inclination angle are alternately connected to form a step shape;

in the diffusion section, a first inclined angle is a first included angle alpha formed by a first step inclined edge and the throat section, a second inclined angle is a second included angle beta formed by a second step inclined edge and the throat section, the multistage steps form an integral wall surface, a third included angle gamma is formed by the integral wall surface, the first step inclined edge and the second step inclined edge, and the third included angle gamma keeps a specific angle value;

the first included angle alpha and the second included angle beta are respectively three combinations of 4.5 degrees, 10.5 degrees, 7 degrees, 13 degrees, 9.5 degrees and 15.5 degrees, and the number of steps corresponding to each combination is different;

a fourth included angle theta formed by the integral wall surface and the throat section is 7.5 degrees, 10 degrees or 12.5 degrees;

the specific angle value is 3 °.

2. The multi-stage venturi-type bubble generating device of claim 1, wherein the inlet tube diameter of the convergent section is the same as the length of the outlet inner tube diameter of the divergent section.

3. The multi-stage venturi-type bubble generating device of claim 2, wherein the length of the tube diameter of the inlet of the convergent section and the length of the tube diameter of the inside of the outlet of the divergent section are both 53 mm.

4. The multi-step venturi-type bubble generating device of claim 1, wherein the length of the constriction section is 37mm, and the length of the throat section is 50 mm.

5. The multi-step venturi-type bubble generating device of claim 1, wherein the throat section penetrates four air intake holes.

6. The multi-step venturi-type bubble generating device of claim 5, wherein the diameter of the air intake hole is 1 mm.