JPS62295662A - Pressure reduced part of fine bubble generator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

3. Detailed description of the invention

【Technical field】

The present invention relates to a pressure reduction section of a microbubble generator for dissolving gas in a liquid under pressure and reducing the pressure of the pressurized liquid to precipitate bubbles.

[Background technology]

In the pressure reduction section of a conventional micro bubble generator, a disk-shaped primary pressure reduction member with an orifice bored in the center is fixed perpendicular to the flow inside the pressure reduction nozzle, and a secondary pressure reduction member is further installed on the opening side of the pressure reduction nozzle. The parts were delivered and fixed. Here, the secondary pressure reducing member was a band-shaped material wound into a coil shape. However, after first reducing the pressure of the pressurized liquid in which gas was dissolved under pressure using a pressure reducing member to generate microbubbles, the pressure was further reduced using a secondary pressure reducing member to generate microbubbles. ,
Furthermore, it was desired to improve the bubble precipitation rate. Further, in such a coil-shaped secondary pressure reducing member, it is difficult to change the diameter and amount of bubbles.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned technical background, and its purpose is to increase the amount of fine bubbles deposited in the pressure reducing section of a fine bubble generator.

[Disclosure of the invention]

The decompression part of the inventive fine bubble generator is a fine bubble generator in which a primary decompression member 2 and a secondary depressurization member 3 are delivered into a cylindrical decompression nozzle 1 that is supplied with a pressurized liquid in which gas is dissolved under pressure. In the decompression generator, the secondary depressurization member 3 is comprised of a perforated plate 5 having a large number of pores 4 and a mesh body 6. When a pressurized liquid in which gas is pressurized and dissolved is injected into the pressure reduction nozzle 1, the pressure of the pressurized liquid is once reduced in the primary pressure reduction member 2, and then further in the pore plate 5 inside the secondary pressure reduction member 3. Secondary pressure is reduced and the pressure is reduced in two stages,
When it collides with the mesh body 6, cavitation occurs and fine bubbles are precipitated, and this process causes a large amount of fine bubbles to be precipitated. Further, by changing the diameter, number, and distribution of the pores 4 of the pore plate 5, it is possible to control the diameter and amount of the microbubbles that are precipitated. Furthermore, by changing the number of meshes 6 used, it is also possible to finely control the diameter and amount of microbubbles. Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. A cylindrical pressure reduction tube 1 is provided at the end of a pipe 9 to which a pressurized liquid in which a gas such as air is dissolved in a liquid such as water by a microbubble generator is sent. In the center of the pressure reduction nozzle 1, a disk-shaped primary pressure reduction member 2 for primary pressure reduction with an orifice 8 bored in the center is arranged perpendicular to the axial direction of the pressure reduction nozzle 1. A secondary pressure reducing member 3 is disposed at. The secondary pressure reducing member 3 has a pore plate 5 having a large number of pores 4 perpendicular to the axial direction fixed to the center of a cylindrical body 7, and has a rear end opening of the cylindrical body 7.
The cylinder body 7 is closed with two mesh bodies 6 made of wire mesh, and the opening at the tip of the cylinder body 7 is closed with two mesh bodies 6 made of wire mesh. Further, the surfaces of the porous plate 5 and the mesh body 6 are treated to be hydrophilic. That is, at least the surfaces of the porous plate 5 and the mesh body 6 are treated to be hydrophilic by molding them with a hydrophilic material, coating their surfaces with a hydrophilic plastic coating, or applying a hydrophilic paint. It is. When a pressurized liquid in which gas is pressurized and dissolved is injected from the pipe 9 into the pressure reduction nozzle 1, the pressure of the pressurized liquid is first reduced by the primary pressure reduction member 2, and 'lII fine bubbles are precipitated. Secondary pressure reduction is performed by the secondary pressure reduction member 3 to precipitate '/a fine bubbles. That is, the pressurized liquid is once depressurized at the orifice 8 of the primary depressurizing member 2, collides with the net 6 of the secondary decompressing member 3, causing cavitation and depositing fine bubbles, and further inside the secondary decompressing member 3. It is secondarily depressurized by the porous plate 5, and collides with the mesh body 6 ahead of it, causing cavitation and precipitating fine bubbles, and this process produces a large amount of fine liters! M bubbles are precipitated. It is possible to control the diameter and amount of microbubbles that are precipitated by changing the diameter, number, and distribution of the pores 4 of the pore plate 5. Furthermore, by changing the number of meshes 6 used, it is also possible to finely control the diameter and amount of microbubbles. Furthermore, since the surfaces of the porous plates 5 and 14 bodies 6 are treated to make them woody, even finer air bubbles can be obtained. FIG. 4 shows the state in which air bubbles precipitated from the pores 4 of the porous plate 5 whose surface has been subjected to hydrophilic treatment are extruded, and FIG. Air bubbles precipitated from the pores 4 are extruded from the pores 4. In general, on the highly hydrophilic surface of the one-button scale, there is a t-angle between the water surface and the hydrophilic surface. (contact angle) becomes smaller, and the angle (contact angle) between the water surface and the hydrophobic surface becomes larger on a hydrophobic surface with low hydrophilicity. As shown in Figure 4, the angle β between the bubble and the hydrophilic surface is
becomes smaller, and on the hydrophobic surface, as shown in Figure 5, the angle a that the bubble makes with the hydrophobic surface becomes larger, and the contact angle with the hydrophobic surface α〉
The contact angle with the hydrophilic surface is β. Due to this phenomenon, when air bubbles are pushed out of the pores 4 in the porous plate 5 which has a hydrophobic surface as shown in FIG. 5, water retreats from the edges of the pores 4 and the air bubbles move The bubbles grow so as to spread laterally as shown in (c), and since the bubbles are difficult to separate from the surface of the porous plate 5, the diameter of the bubbles increases and they separate from the porous plate 5. However, the pore plate 5
When the surface of is subjected to hydrophilic treatment and ζ, the bubbles pushed out from the pores 4 cannot spread laterally because the force of water adhering to the surface of the pore plate 5 is strong, so that the bubbles are forced out from the pores 4 and cannot spread laterally. The air bubbles are pushed forward in this manner, and the air bubbles remain small and are peeled off from the surface of the porous plate 5 and released, resulting in fine air bubbles. This effect is the same for the mesh body 6 as well.

【Effect of the invention】

In the present invention, as described above, since the secondary pressure reducing member is constituted by the pore plate having a large number of pores and the mesh body, the pressurized liquid is depressurized in two stages by the primary pressure reducing member and the pore plate. Furthermore, it has the advantage that it collides with the mesh body to cause cavitation to precipitate fine bubbles, and a large amount of fine bubbles can be precipitated. In addition, by changing the diameter, number, and distribution of the pores in the pore plate, it is possible to control the diameter and amount of the microbubbles that precipitate, and by changing the number of mesh plates used, the diameter of the microbubbles can be controlled. It is also possible to perform small amount rolls.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a secondary pressure reducing member in an embodiment of the present invention, Fig. 2 is a perspective view of the same, Fig. 3 is a sectional view showing the pressure reducing part of the same, and Fig. WIJ4 is an explanatory diagram of the operation of the same. , FIG. 5 is an explanatory diagram of the operation of a comparative example. 1... Pressure reduction nozzle 2... - Person pressure reduction member 3... Secondary pressure reduction member 4... Pore 5... Pore plate 6... Net body

Claims (2)

[Claims] (1) In the pressure reducing section of a micro bubble generator, in which a primary pressure reducing member and a secondary pressure reducing member are delivered into a cylindrical pressure reducing nozzle that is supplied with a pressurized liquid in which gas is dissolved under pressure, in the axial direction of the pressure reducing nozzle. A pressure reducing section of a micro bubble generator, characterized in that a secondary pressure reducing member is constituted by a mesh body and a pore plate having a large number of pores arranged in a direction perpendicular to the pores. (2) The pressure reducing section of the microbubble generator according to claim 1, characterized in that the surfaces of the pore plate and the mesh body are subjected to hydrophilic treatment.