WO2023070832A1

WO2023070832A1 - Multi-channel venturi tube hydrodynamic cavitation generation device

Info

Publication number: WO2023070832A1
Application number: PCT/CN2021/135370
Authority: WO
Inventors: 史鸿博; 李亚林
Original assignee: 江苏大学
Priority date: 2021-10-26
Filing date: 2021-12-03
Publication date: 2023-05-04
Also published as: CN114210464A

Abstract

The present invention relates to the technical field of hydrodynamic cavitation, and provides a multi-channel Venturi tube hydrodynamic cavitation generation device. An arc-shaped throat tube and the input end of a throat tube section are communicated with the output end of an inlet tube, and the output end of the throat tube section is connected to an diverging section. The diverging section is a gradually expanding tube, and a fluid blocking body is provided in the diverging section by means of a fixing rod. The arc-shaped throat tube is communicated with an annular tube, and the output end of the annular tube is provided with a shunting throat tube. The output end of the shunting throat tube is provided in the diverging section and is arranged above the fluid blocking body. By providing the arc-shaped throat tube and the annular tube, when a water flow enters, the water flow is shunted by means of a plurality of shunting throat tubes, cavitation and discharge are carried out in the annular tube, and the water flow normally passing through a Venturi tube can be shunted again by means of the fluid blocking body for cavitation, such that the effect of multiple cavitation is achieved. The problem of incomplete cavitation caused by only a single cavitation path in the traditional Venturi tube is solved, and the present invention has the advantage of enhancing the cavitation efficiency by achieving multiple times of cavitation in a limited space.

Description

A multi-channel Venturi tube hydraulic cavitation generating device

technical field

The invention relates to the technical field of hydraulic cavitation, in particular to a Venturi tube cavitation strengthening device for mineral flotation.

Background technique

Tailings often contain many particulate minerals. It is an important science and technology to use advanced technology to "turn waste into treasure" and large-scale utilization of tailings resources. The tailings extraction process uses a Venturi tube with a flotation column to float mineral particles through micro-nano bubbles. Among them, the Venturi tube hydraulic cavitation reactor is a key technology for separating and recovering useful particulate minerals in tailings, and its cavitation performance directly affects the extraction efficiency of tailings. Cavitation is the process of the formation, development and collapse of vapor or gas cavities (cavitations) inside the liquid or on the liquid-solid interface when the local pressure in the liquid decreases. Venturi tubes are usually used for cavitation.

Chinese Patent Publication No. CN110339696A discloses a Venturi hydraulic cavitation reactor, which includes an inlet tapered section, a throat and an outlet tapered section, the throat is provided with an air inlet, and the throat is provided with a porous plate , the side of the air inlet is close to the tapered section of the inlet, and the side of the perforated plate is close to the tapered section of the outlet. Through the above-mentioned technical solution, the patent installs a multi-hole plate and an air inlet at the venturi throat to enhance the cavitation effect. However, the throat is the initial low-pressure area of cavitation in the Venturi tube. Introducing external gas in this area will introduce additional high-pressure gas, which will increase the pressure of the Venturi throat, which cannot meet the conditions for cavitation to occur, greatly affecting the hydraulic cavitation reaction. The cavitation efficiency of the device. In addition, the cavitation method of the hydraulic cavitation reactor is relatively simple, and there is only one cavitation channel in the pipe, the cavitation formed by it is not thorough enough, and it cannot achieve a sufficient level of hydraulic cavitation in applications that require cavitation performance .

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a Venturi tube cavitation strengthening device for mineral flotation, which has the advantage of being able to cavitate multiple times, and solves the problem that there is only one water passage in the traditional Venturi tube. The problem of single cavitation path and incomplete cavitation has further improved the cavitation rate of a single Venturi tube through a variety of ways to strengthen cavitation.

The present invention achieves the above-mentioned technical purpose through the following technical means.

A Venturi tube cavitation strengthening device for mineral flotation, comprising an inlet pipe and a Venturi tube body, the Venturi tube body includes an expansion section and a throat section; the input end of the throat section and the output end of the inlet pipe In communication, the output end of the throat section is connected with an expansion section; the expansion section is a gradual expansion tube, and a bluff body is arranged in the expansion section through a fixed rod; the bluff body is a hollow structure; the output end of the inlet pipe is connected to the arc The throats are connected, and the arc-shaped throat is connected with an annular pipe, and the output end of the annular pipe is provided with a shunt throat; the output end of the shunt throat is arranged in the expansion section and placed above the bluff body.

Further, the water inlet pipe is a hollow cylindrical structure, and an air injection hole is opened on the side wall of the water inlet pipe; several holes are opened on the bottom plate of the hollow cylindrical structure, and the holes on the water inlet pipe are connected with the arc-shaped throat and throat. pipe connection.

Further, a spiral impeller is arranged in the water inlet pipe.

Further, the blades of the spiral impeller are supercavitation blades.

Further, the apertures of the arc-shaped throat and the split throat are both smaller than the aperture of the annular pipe.

Further, an orifice is arranged in the arc-shaped throat.

Further, both the bluff body and the annular tube are provided with permanent magnets.

Further, the annular pipe is a spherical structure.

Further, the bluff body is a hollow tube, which gradually expands along the fluid direction.

Further, the air injection holes are equidistantly distributed on the water inlet pipe along the circumferential direction.

Compared with the prior art, the beneficial effects of the present invention are as follows:

1. The invention installs a spiral impeller inside the inlet pipe. When the water flow enters, the rotation of the impeller will increase the degree of disturbance of the water flow, enhance the energy of the water flow, and provide favorable conditions for strong cavitation reactions.

2. The present invention sets the spiral impeller as a super-cavitation blade airfoil, and processes a series of ribs of the same type on the surface of the impeller to increase the contact area between the blade and the water body, aggravate the disturbance of the fluid to form more cavitation , to achieve the purpose of strengthening cavitation. The airfoil of the blade is thin and sharp, and a series of bubbles are induced directly on the back of the blade at the inlet pipe, and the bubbles move with the vortex to avoid cavitation damage to the blade due to direct collapse on the blade surface. When the bubbles enter the main body of the Venturi tube, under the action of the centrifugal force provided by the helical impeller, the bubbles gather near the axis of the pipe. This ensures that the location where the hydraulic cavitation occurs is far away from the inner wall of the Venturi tube, thereby reducing cavitation damage to the tube wall caused by bubble collapse while ensuring the occurrence of cavitation.

3. The present invention evenly arranges the gas injection holes at intervals of 90° in the circumferential direction on the wall of the inlet pipe, which does not increase the pressure value of the low-pressure area of the throat, but also increases the bubbles in the fluid to provide the necessary gas core for cavitation , in order to achieve the purpose of strengthening the occurrence of hydraulic cavitation.

4. In the present invention, the inlet pipe is arranged in a cylindrical shape, and the inlet pipe is directly connected with the throat section of the Venturi tube body in a straight line. When the water flow enters the throat through the inlet pipe, increasing the contraction angle will increase the inflow velocity and generate Relatively large pressure drop, while reducing turbulence intensity, finally achieves the purpose of increasing the cavitation rate in the diffusion section and effectively ensuring the occurrence of hydraulic cavitation.

5. The present invention arranges an annular pipe inside the Venturi tube body. When the water flow enters, the water flow is diverted through multiple diversion throats, and cavitation is discharged in the annular pipe, while the water flow that normally passes through the Venturi tube will pass through The bluff body divides the flow again for cavitation, so as to achieve the effect of multiple cavitation, which solves the problem of single water passage and cavitation path in the traditional Venturi tube, and the problem of incomplete cavitation, and has multiple cavitation in a limited space. The advantage of enhancing cavitation efficiency.

6. In the present invention, permanent magnets are provided, and the magnetic field generated by the permanent magnets can prolong the life of active free radicals and achieve the purpose of strengthening cleaning and disinfection.

7. The present invention sets a hollow bluff body. After the water flow enters the expansion section through the throat section, it will be divided by the bluff body. The water flow passing inside the bluff body, because the inlet of the bluff body is small, its internal space and outlet are large, can form a shape similar to a Venturi tube to perform cavitation again.

8. The present invention is connected by setting a fixed rod, so that the bluff body can be suspended inside the annular tube, so that it can cooperate with the annular tube to reduce the diameter of the water flow through, and the water flow sliding over the outer wall of the bluff body can be cavitated here .

9. In the present invention, the apertures of the arc-shaped throat and the shunt throat are set to be smaller than the aperture of the annular pipe. After the water flow is cavitated by the cooperation of the arc-shaped throat and the annular pipe, the water flow is guided through the shunt throat, so that the ring The water flow in the pipe can conduct convective collision after going out of the pipe, which can promote the generation of cavitation bubbles and enhance the intensity of cavitation.

10. In the present invention, by setting the orifice plate, the fluid enters the fluid inlet pipe and passes through the orifice plate. Due to the throttling effect of the orifice plate, the flow rate increases and the hydrostatic pressure decreases. When the pressure reaches or even lower than the saturated steam of the fluid at this temperature When the pressure is high, the fluid starts to gasify to generate bubbles, and the gas dissolved in the fluid is also precipitated in the form of bubbles, which can play a role in assisting cavitation.

Description of drawings

Fig. 1 is a kind of Venturi tube cavitation strengthening device structural representation for mineral flotation of the present invention;

The reference signs are as follows:

1-Inlet pipe; 2-Venturi tube body; 3-Ring pipe; 4-Shunt throat; 5-Arc throat; 6-Bag body; 10-air injection hole; 11-spiral impeller; 12-throat section.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

In describing the present invention, it is to be understood that the terms "central", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "axial", The orientation or positional relationship indicated by "radial", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description , rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus should not be construed as limiting the invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In conjunction with accompanying drawing 1, a Venturi tube cavitation strengthening device for mineral flotation, including an inlet pipe 1, the inlet pipe 1 is cylindrically arranged, and a spiral impeller 11 is installed in the inlet pipe 1 along the axial direction, and the spiral impeller 11 A series of ridges are processed on the surface of the blade, and the inlet pipe 1 is uniformly arranged with injection holes 10 at intervals of 90° in the circumferential direction. section, the extension section is fixedly connected to the top of the throat section 12, the extension section is in the shape of a trumpet with a large upper part and a smaller lower part, the outer side wall of the annular pipe 3 is fixedly connected to the extended section of the Venturi tube body 2, and the annular pipe 3 is a spherical structure, The annular pipe 3 is a hollow pipe with a circular cross-sectional shape. The inner side of the annular pipe 3 is provided with a circular hollow. The top of the annular pipe 3 is connected with a shunt throat 4. The outside of the inner pipe body 2 and the outer wall of the inlet pipe 1 are connected with arc-shaped throats 5. Two arc-shaped throats are respectively arranged on both sides of the Venturi tube body 2 and are suspended. The top of the arc-shaped throat 5 is connected to the ring The tube 3 is connected, and the expansion section of the Venturi tube body 2 is provided with a bluff body 6 located inside the annular tube 3. The bluff body 6 is located in a circular hollow inside the annular tube 3, and the bluff body 6 is connected to the annular tube 3. The gap between the inner sidewalls forms an annular flow blocking area.

Combined with the accompanying drawing 1, the inlet pipe 1 is a hollow cylindrical straight pipe structure, which can increase the inflow velocity relative to the conical junction, thereby generating a relatively large pressure drop in the pipe, while reducing the turbulence intensity, and finally achieving improved cavitation in the diffusion section High efficiency, effectively guarantee the purpose of hydraulic cavitation.

Referring to FIG. 1 , gas injection holes are evenly arranged on the wall surface of the inlet pipe 1 at intervals of 90° in the circumferential direction.

As a technical optimization scheme of the present invention, additional inert gas is injected into the pipe through the gas injection hole located in the high-pressure area of the inlet pipe, which does not increase the pressure value in the low-pressure area of the throat, and can additionally increase the bubbles in the fluid to provide cavitation The necessary gas core is generated to achieve the purpose of strengthening the occurrence of hydrodynamic cavitation.

Referring to FIG. 1 , a helical impeller 11 is installed in the venturi inlet pipe 1 at the axial position.

As a technical optimization scheme of the present invention, the rotation of the helical impeller adds additional disturbance to the water body, enhances the flow energy of the water, and provides powerful conditions for strengthening the cavitation reaction. The raised ribs on the blades of the impeller increase the contact area between the blades and the water body, aggravate the disturbance of the fluid to form more cavitation, and achieve the purpose of strengthening the occurrence of cavitation. A series of bubbles are induced at the inlet pipe 1 by the thin and pointed blades, and the bubbles move with the vortex to avoid cavitation damage to the blades caused by direct collapse on the blade surface. When the bubbles enter the main body of the Venturi tube, under the action of the centrifugal force provided by the helical impeller, the bubbles gather near the axis of the pipe. Ensure that the location where hydraulic cavitation occurs is far away from the inner wall of the Venturi tube, so as to meet the conditions for cavitation and reduce the cavitation damage to the tube wall caused by bubble collapse.

Referring to FIG. 1 , the extended section of the Venturi tube body 2 , the inner wall of the annular tube 3 and the bluff body 6 are all fixedly connected to the permanent magnet 7 .

As a technical optimization scheme of the present invention, by setting the permanent magnet 7, the magnetic field generated by the permanent magnet 7 can prolong the life of active free radicals, and achieve the purpose of strengthening cleaning and disinfection.

Referring to FIG. 1 , the shape of the bluff body 6 is hollow, and the top and bottom of the bluff body 6 are both provided with openings, and the opening at the bottom of the bluff body 6 is smaller than the opening at the top.

As a technical optimization scheme of the present invention, by setting the hollow bluff body 6, after the water flow passes through the throat section and enters the extension section, it will be shunted by the bluff body 6, one part passes through the hollow shape of the bluff body 6, and the other part passes through The outer wall of the bluff body 6 slides over, and the water flow passing through the inside of the bluff body 6 can form a shape similar to a Venturi tube for cavitation because the inlet of the bluff body 6 is small, and its internal space and outlet are relatively large.

Referring to Fig. 1, the outer wall of the bluff body 6 is fixedly connected with a fixed rod 8, and the ends of the fixed rod 8 away from the bluff body 6 are respectively fixedly connected with the inner wall of the Venturi tube body 2 and the annular pipe 3, between the bluff body 6 and the annular pipe 3 The spacing is smaller than the aperture of the venturi tube body 2 throat section.

As a technical optimization solution of the present invention, the bluff body 6 can be suspended inside the annular tube 3 by setting the fixed rod 8 for connection, so that it can cooperate with the annular tube 3 to reduce the diameter of the water flow through, and from the bluff body 6 Water flowing over the outer wall can be cavitated here.

Referring to FIG. 1 , the apertures of the arc-shaped throat 5 and the shunt throat 4 are both smaller than the aperture of the annular pipe 3 .

As a technical optimization scheme of the present invention, by setting the apertures of the arc-shaped throat 5 and the shunt throat 4 to be smaller than the aperture of the annular pipe 3, after the water flow is cavitated by the cooperation of the arc-shaped throat 5 and the annular pipe 3, The water flow is guided through the shunt throat 4, so that the water flow in the annular pipe 3 can undergo convective collision after going out of the pipe, which can promote the generation of cavitation bubbles and enhance the cavitation intensity.

Referring to FIG. 1 , an orifice plate 9 is fixedly connected to the inside of the arc-shaped throat pipe 5 .

As a technical optimization scheme of the present invention, by setting the orifice plate 9, the fluid enters the fluid inlet pipe 1 and passes through the orifice plate 9. Due to the throttling effect of the orifice plate 9, the flow rate increases and the hydrostatic pressure decreases. When the pressure reaches Even when the temperature is lower than the saturated vapor pressure of the fluid at this temperature, the fluid begins to vaporize to generate bubbles, and the gas dissolved in the fluid is also precipitated in the form of bubbles, which can play a role in assisting cavitation.

When the water flow enters from the inlet pipe 1, it will enter the arc throat 5 and the throat section 12 of the Venturi tube body 2. The water flow is divided into multiple streams for cavitation. After entering the arc throat 5, it will pass through the hole Plate 9, due to the throttling effect of the orifice plate 9, the flow rate increases and the hydrostatic pressure decreases. When the pressure reaches or is even lower than the saturated vapor pressure of the fluid at this temperature, the fluid begins to gasify to generate bubbles, and the dissolved in the fluid The gas is also precipitated in the form of bubbles, which can play the role of auxiliary cavitation, and then enters the annular pipe 3 for cavitation, and after being cavitated in the annular pipe 3, it is discharged by the shunt throat 4 for convective collision, in which the gas passes through the Venturi tube body 2 The water flow in the throat section enters the extension section and undergoes cavitation once, and then is blocked and divided by the bluff body 6. One of the water flows will enter the interior of the bluff body 6 for cavitation, and the other water flows will adhere to the outer wall of the bluff body 6, and the water flow will The annular choke area formed by the gap between the bluff body 6 and the inner wall of the annular pipe 3 is cavitated, thereby achieving the purpose of multiple cavitations.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations to the present invention. Variations, modifications, substitutions, and modifications to the above-described embodiments are possible within the scope of the present invention.

Claims

A Venturi tube cavitation strengthening device for mineral flotation, comprising an inlet pipe (1) and a Venturi tube body (2), characterized in that the Venturi tube body (2) includes an expansion section and a throat section (12); the input end of the throat section (12) communicates with the output end of the inlet pipe (1), and the output end of the throat section (12) is connected with an expansion section; the expansion section is an expanding tube, and the expansion section passes through The fixed rod (8) is provided with a bluff body (6); the bluff body (6) is a hollow structure; the output end of the inlet pipe (1) communicates with the arc-shaped throat (5), and the arc-shaped throat (5) ) is connected with an annular pipe (3), and the output end of the annular pipe (3) is provided with a shunt throat (4); the output end of the shunt throat (4) is arranged in the expansion section, and placed The upper position of the fluid (6).
The Venturi tube cavitation strengthening device for mineral flotation according to claim 1, characterized in that, the water inlet pipe (1) is a hollow cylindrical structure, and the side wall of the water inlet pipe (1) is opened There are air injection holes (10); several holes are opened on the bottom plate of the hollow cylindrical structure, and the holes on the water inlet pipe (1) communicate with the arc-shaped throat (5) and the throat section (12).
The Venturi tube cavitation strengthening device for mineral flotation according to claim 1, characterized in that a spiral impeller (11) is arranged in the water inlet pipe (1).
The Venturi tube cavitation strengthening device for mineral flotation according to claim 3, characterized in that the blades of the spiral impeller (11) are supercavitation blades.
The Venturi tube cavitation strengthening device for mineral flotation according to claim 1, characterized in that the apertures of the arc-shaped throat (5) and the shunt throat (4) are smaller than the annular pipe (3) aperture.
The Venturi tube cavitation strengthening device for mineral flotation according to claim 1, characterized in that an orifice plate (9) is arranged in the arc-shaped throat (5).
The Venturi tube cavitation strengthening device for mineral flotation according to claim 1, characterized in that permanent magnets (7) are arranged inside the bluff body (6) and the annular pipe (3).
The Venturi tube cavitation strengthening device for mineral flotation according to claim 1, characterized in that the annular tube (3) is a spherical structure.
The Venturi tube cavitation strengthening device for mineral flotation according to claim 1, characterized in that, the bluff body (6) is a hollow tube and is gradually expanding along the fluid direction.
The Venturi tube cavitation strengthening device for mineral flotation according to claim 2, characterized in that the gas injection holes (10) are equidistantly distributed on the water inlet pipe (1) along the circumferential direction.