JP7042013B2 - Fine bubble generator - Google Patents

Description

The present invention relates to a fine bubble generator that is attached to, for example, a shower head or a hose and generates minute bubbles called microbubbles or nanobubbles in a liquid such as cold water or hot water.

Various fine bubble generators have been proposed that can be easily attached to water faucets, shower heads, etc. to generate microbubbles and nanobubbles. Generally, microbubbles refer to bubbles having a diameter in the range of 1 μm to several tens of μm, and nanobubbles refer to bubbles having a diameter in the range of 1 nm to 1000 nm (1 μm). Further, the fine bubble includes both microbubbles and nanobubbles.

Patent Document 1 relates to a device connected to a faucet or the like to generate microbubbles, and describes air from the outside by a flow path through which a liquid (water) discharged from the faucet or the like passes and a negative pressure generated by the flow of the liquid. It is provided with a gas introduction path for sucking a gas, and a hollow portion in which a mixture of a liquid and an air is swirled and stirred in a spiral manner, whereby air bubbles in the liquid are refined to generate micro bubbles.

Patent Document 2 relates to a fine bubble generator installed in a fluid pipe, and is composed of a cylinder and a flange. The cylinder is provided with a through hole for spirally swirling a liquid, and centrifugal force is provided. A pressure difference is generated between the central portion and the peripheral portion of the through hole, and bubbles are generated by the air dissolved in the liquid in the liquid flowing through the central portion of the decompressed through hole. The cross section of the through hole is a constricted shape with a narrow center, such as a gourd type or a weight type.

Japanese Unexamined Patent Publication No. 2005-305219 Japanese Unexamined Patent Publication No. 2018-58038 (Patent No. 6312768)

In the apparatus described in Patent Document 1, since the liquid and the air are only mixed and the mixture of the liquid and the air is agitated, it is difficult to generate a large amount of finer nanobubbles. Further, in the apparatus described in Patent Document 2, although it is possible to generate nanobubbles, the nanobubbles are exclusively through holes because the pressure difference generated between the central portion and the peripheral portion of the through hole is used. It is considered that nanobubbles are hardly generated in the liquid passing through the peripheral part of the through hole pressurized by the centrifugal force, which is generated only in the liquid passing through the central part of the. Therefore, the amount of nanobubbles generated may not be sufficient.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a fine bubble generator capable of generating a sufficient amount of nanobubbles while having a simple structure.

The fine bubble generator according to the present invention communicates with the main body portion having a substantially cylindrical outer shape, the liquid introduction portion formed at the first end portion on the side where the liquid flows in, and the liquid introduction portion, and the main body portion. With a through hole that penetrates in its central axis direction,
The liquid introduction portion has a substantially circular opening at the first end portion of the main body portion, and is opposite to the first end portion of the main body portion in a predetermined cross section including the central axis of the main body portion. It is formed so that the cross-sectional area gradually decreases toward the second end of the
In any cross section perpendicular to the central axis of the body, the through hole comprises the central axis of the body and is orthogonal to the central region including the narrowest portion in the first direction. It is formed symmetrically with respect to the central axis of the main body in the second direction, and is formed by a first peripheral region and a second peripheral region including the widest portion in the first direction. The first peripheral region and the second peripheral region are communicated by a continuous curve having no corners.
Any cross section perpendicular to the central axis of the main body defining the through hole is at least 270 degrees from the first end side toward the second end side along the central axis direction of the main body. It's spinning ,
In any cross section perpendicular to the central axis of the body
The central region has a first radius that is inwardly convex with respect to the central axis of the main body, passes through the central axis of the main body, and is symmetrically opposed to the axis of symmetry parallel to the second direction. Formed by two first radii,
The first peripheral region and the second peripheral region each have a second radius centered on the central axis of the main body portion, and have a second radius portion that is outwardly convex with respect to the central axis of the main body portion. On the central axis of the main body, which has a third radius larger than the first radius and smaller than the second radius, is symmetric with respect to the axis of symmetry, and is continuous with the second radius. It has two outwardly convex third radii and a fourth radius smaller than the first radius, is symmetrical with respect to the axis of symmetry, and is continuous with the third radius and the first radius. It is formed by two fourth radial portions that are convex outward with respect to the central axis of the main body portion.
It is characterized by that.

The other fine bubble generator according to the present invention communicates with the main body portion having a substantially cylindrical outer shape, the liquid introduction portion formed at the first end portion on the side where the liquid flows in, and the liquid introduction portion. It has a through hole that penetrates the main body in the direction of its central axis.
The liquid introduction portion has a substantially circular opening at the first end portion of the main body portion, and is opposite to the first end portion of the main body portion in a predetermined cross section including the central axis of the main body portion. It is formed so that the cross-sectional area gradually decreases toward the second end of the
In any cross section perpendicular to the central axis of the body, the through hole comprises the central axis of the body and is orthogonal to the central region including the narrowest portion in the first direction. It is formed symmetrically with respect to the central axis of the main body in the second direction, and is formed by a first peripheral region and a second peripheral region including the widest portion in the first direction. The first peripheral region and the second peripheral region are communicated by a continuous curve having no corners.
Any cross section perpendicular to the central axis of the main body defining the through hole is at least 270 degrees from the first end side toward the second end side along the central axis direction of the main body. It's spinning,
In any cross section perpendicular to the central axis of the body
The central region has a first radius that is inwardly convex with respect to the central axis of the main body, passes through the central axis of the main body, and is symmetrically opposed to the axis of symmetry parallel to the second direction. Formed by two first radii,
The first peripheral region and the second peripheral region each have a second radius centered on the central axis of the main body portion, and have a second radius portion that is outwardly convex with respect to the central axis of the main body portion. , Which has a fourth radius smaller than the first radius, is symmetric with respect to the axis of symmetry, and is continuous with the first radius portion and the second radius portion, and is outward with respect to the central axis of the main body portion. It is formed by two convex fourth radii,
The ratio W1: W2 of the dimension W1 of the narrowest portion of the central region in the first direction and the dimension W2 of the widest portion of the first peripheral region and the second peripheral region in the first direction is , 1: 5.75 to 1: 9.25,
The ratio R1: R2 of the radius R1 of the first radius portion and the radius R2 of the second radius portion is 1: 2.5.
It is characterized by that.

In the above configuration, the liquid introduction portion may be configured to be formed in a continuous curved shape having no corners in a predetermined cross section including the central axis of the main body portion.

Further, the ratio of the dimension of the narrowest portion of the central region in the first direction to the dimension of the widest portion of the first peripheral region and the second peripheral region in the first direction is 1: 1. It may be configured to be in the range of 5.75 to 1: 9.25.

The fine bubble generator is used by being mounted inside a shower head or a hose, for example. It is considered that the liquid such as water flows in the water supply pipe in a pressurized state and is dissolved in the liquid in a saturated state of air. According to the above configuration, the liquid introduction portion is formed at the first end portion of the main body portion having a substantially cylindrical outer shape on the side where the liquid flows in, and the liquid introduction portion is communicated with the through hole. Since the central region of the through hole penetrates almost straight along the central axis of the main body, the liquid that has flowed into the central region of the liquid introduction portion flows into the central region of the through hole at almost the same pressure and flow velocity. .. On the other hand, the liquid that has flowed into the peripheral region of the liquid introduction portion collides with the side wall of the liquid introduction portion and is pressurized and accelerated. Therefore, even in the liquid introduction portion, a pressure difference occurs between the liquid flowing in the central region and the liquid flowing in the peripheral region. Therefore, it is considered that bubbles are generated in the liquid flowing in the central region even in the liquid introduction portion.

Next, among the liquids that have flowed into the through holes, the liquids that have flowed into the central region flow straight along the central axis of the main body at the same pressure and flow velocity with almost no rotation. On the other hand, among the liquids that have flowed into the through holes, the liquids that have flowed into the first peripheral region and the second peripheral region are spirally swirled along the outer periphery of the substantially cylindrical main body portion by the rotation of the through holes. Centrifugal force acts on the swirled liquid, and the liquid flows so as to concentrate in the region of the first peripheral region and the second peripheral region far from the central axis of the main body. Therefore, inside the through hole, a pressure difference is generated between the liquid flowing in the central region and the liquid flowing in the first peripheral region and the second peripheral region, and bubbles are generated in the liquid flowing in the central region due to the depressurizing action. In addition, the speed difference between the liquid flowing in the central region of the through hole and the liquid flowing in the first peripheral region and the second peripheral region of the through hole causes a violent vortex in the liquid flowing through the through hole, which also generates bubbles. do. Further, among the liquids flowing in the first peripheral region and the second peripheral region, a pressure difference is generated between the liquid flowing in the region on the outer peripheral side of the main body and the liquid flowing in the region near the central axis, and the decompression action causes the first. Bubbles are also generated in the liquid flowing through the 1 peripheral region and the 2nd peripheral region.

The cross-sectional area of the second end of the main body, that is, the through hole on the side where the liquid is discharged is smaller than the cross-sectional area of the substantially circular opening of the liquid introduction portion of the first end of the main body. When the liquid is discharged from the second end portion of the portion, a cavity close to a vacuum in which the liquid does not flow is generated inside the shower head or the hose and in the vicinity of the second end portion of the main body portion. Therefore, due to the negative pressure of the cavity, the air dissolved in the liquid discharged from the second end of the main body is foamed at once, and a large amount of fine bubbles are generated in the liquid. As described above, according to the fine bubble generator according to the present invention, bubbles are generated due to various factors, so that the amount of fine bubbles generated is increased as compared with the conventional apparatus described in, for example, Patent Document 2. Can be made to.

The cross-sectional view which shows an example of the use state of the fine bubble generator which concerns on this invention. The perspective view which shows the appearance structure of the fine bubble generator which concerns on this invention. A predetermined cross-sectional view including the central axis of the main body of the fine bubble generator. The figure which shows the cross-sectional shape of the through hole in an arbitrary cross section perpendicular to the central axis of the main body part. A front view of the main body as seen from the first end side thereof. The figure which shows the cross-sectional shape of the through hole of the 1st comparative example. The figure which shows the cross-sectional shape of the through hole of the 2nd comparative example. The figure which shows the cross-sectional shape of the through hole of the 1st modification of the fine bubble generator which concerns on this invention.

A fine bubble generator according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an example of a usage state of the fine bubble generator 1 according to the present invention, and the fine bubble generator 1 is installed and used inside, for example, a shower head 2 or a hose 3. Liquids such as cold water and hot water flow in the direction indicated by the arrows in the figure. FIG. 2 is a perspective view showing an external configuration of the fine bubble generator 1 according to the present invention, and in particular, shows a state seen from the side of the first end portion 11 into which the liquid flows. FIG. 3 shows a predetermined cross section (AA cross section of FIG. 5) including the central axis L1 of the main body 10 of the fine bubble generator 1.

As shown in each figure, in the fine bubble generator 1 according to the present embodiment, the liquid introduction portion 20 is formed at the first end portion 11 on the side where the liquid flows into the substantially cylindrical main body portion 10. Further, the main body portion 10 is formed with a through hole 30 that communicates with the liquid introduction portion 20 and penetrates the main body portion 10 in the direction of the central axis L1 to the second end portion 12 on the opposite side of the first end portion 11. Has been done. The liquid introduction portion 20 has a substantially circular opening 25 in the first end portion 11 of the main body portion 10, and is gradually cut toward the second end portion 12 on the side opposite to the first end portion 11 of the main body portion 10. It is formed in a continuous curved shape with no corners, so-called bowl-shaped or ball-shaped, with a reduced area. Further, the liquid introduction portion 20 may have a cross section formed in a truncated cone shape.

FIG. 4 shows a specific example of the cross-sectional shape of the through hole 30 in an arbitrary cross section perpendicular to the central axis L1 of the main body portion 10 (hereinafter, referred to as “through hole 30 of the present invention”). "Arbitrary" means that it has the same cross-sectional shape no matter where it is cut, such as Kintaro-ame, but the through hole 30 is the central axis L1 of the main body 10 that defines the through hole 30. Any cross section perpendicular to is continuously rotated at a constant rate from the first end side 11 to the second end 12 side along the central axis L1 direction of the main body 10. The numerical value shown in FIG. 3 indicates the rotation angle of the cross section defining the through hole 30, and the cross section defining the through hole 30 is rotated about 320 degrees from the first end side 11 to the second end 12 side. ing. Further, in the region indicated by the reference numeral P, the second radial portions 32a and 33a of the first peripheral region 32 and the second peripheral region 33 of the through hole 30 described later appear as a cross section. In the region indicated by reference numeral Q, the third radial portions 32b, 33b and the fourth radial portions 32c, 33c of the first peripheral region 32 and the second peripheral region 33 of the through hole 30 appear as cross sections. In the region indicated by reference numeral R, the ridgeline portion of the first radius portion 31a of the central region 31 of the through hole 30 appears as a cross section. Then, in the region indicated by reference numeral S, a portion having the minimum width of the central region 31 of the through hole 30 appears as a cross section.

The rotation angle of the cross section defining the through hole 30 is substantially proportional to the total length of the portion of the main body 10 in the central axis L1 direction excluding the liquid introduction portion 20. The larger the rotation angle of the cross section defining the through hole 30, the larger the liquid is swirled inside the through hole 30, and the amount of fine bubbles generated increases accordingly. On the other hand, the larger the rotation angle of the cross section defining the through hole 30, the lower the strength of the mold and the more difficult it is to process the mold. As a result of the trial production by the present applicant, if the rotation angle of the cross section defining the through hole 30 is about 720 degrees, that is, about two rotations, it is possible to manufacture a mold and the main body 10 using the mold. be.

In the above arbitrary cross section, the through hole 30 is divided into roughly three regions, includes the central axis L1 of the main body portion 10, and is the narrowest portion in the first direction (X direction) (the minimum width is W1). The maximum width is W2, which is formed symmetrically with respect to the central axis L1 of the main body 10 in the second direction (Y direction) orthogonal to the first direction and the central region 31 including. It is formed by a first peripheral region 32 and a second peripheral region 33 including the above.

The central region 31 has a first radius R1 that is inwardly convex with respect to the central axis L1 of the main body portion 10, passes through the central axis L1 of the main body portion, and is symmetrical with respect to the axis of symmetry L3 parallel to the second direction. It is formed by two first radius portions 31a facing each other. The first peripheral region 32 and the second peripheral region 33 each have a second radius R2 centered on the central axis L1 of the main body portion 10, and the second peripheral region 32 is outwardly convex with respect to the central axis L1 of the main body portion 10. It has radius portions 32a and 33a and a third radius R3 that is larger than the first radius R1 and smaller than the second radius R2, and is symmetric with respect to the axis of symmetry L3 perpendicular to the axis of symmetry L2 and has a second radius. It has two third radius portions 32b and 33b that are continuous with the portions 32a and 33a and are outwardly convex with respect to the central axis L1 of the main body portion 10, and a fourth radius R4 smaller than the first radius R1. Formed by two fourth radius portions 32c, 33c that are symmetrical with respect to L2 and are continuous with the third radius portions 32b and 33b and are outwardly convex with respect to the central axis L1 of the main body portion 10. Has been done. As a result, the central region 31, the first peripheral region 32, and the second peripheral region 33 are communicated with each other by a continuous curve having no corners.

FIG. 5 is a front view of the main body portion 10 as viewed from the first end portion 11 side thereof. For convenience of drawing, the slope 34 of the through hole 30 is expressed as a contour line obtained by rotating the through hole 30 shown in FIG. 4 at a predetermined angle (5 degrees) and superimposing the contour line, but the slope 34 of the through hole 30 is actually not formed. It is a continuous smooth slope. The slopes 21 and 22 of the liquid introduction portion 20 are inclined toward the second peripheral region 33 so that the liquid flowing along the slopes 21 and 22 flows down to the second peripheral region 33 of the through hole 30. Further, the slopes 23 and 24 are inclined toward the first peripheral region 32 so that the liquid flowing along the slopes 23 and 24 flows down to the first peripheral region 32 of the through hole 30. These slopes 21 to 24 are drawn from the first end portion 11 to the second end portion in the central axis L1 direction of the main body portion 10 in order to pull out the main body portion 10 while rotating the mold (inner mold) for injection molding. It is formed in a spiral shape so as to proceed while rotating to 12.

Next, the flow of the liquid flowing into the first end portion 11 of the main body portion 10 of the fine bubble generator 1 according to the present embodiment will be examined. It is considered that the liquid such as cold water or hot water flows in the hose 3 (water supply pipe) in a pressurized state, and is dissolved in the liquid in a saturated state of air. A liquid introduction portion 20 is formed at the first end portion 11 on the side of the substantially cylindrical main body portion 10 on the side where the liquid flows, and the liquid introduction portion 20 is communicated with the through hole 30. As shown in FIG. 1, the circular opening 25 formed in the first end portion 11 of the main body portion 10 of the liquid introduction portion 20 has a diameter substantially the same as the inner diameter of the hose 3. Therefore, the liquid flowing in the hose 3 flows into the liquid introduction portion 20 almost as it is without being blocked by the end surface of the first end portion 11 of the main body 10.

Since the central region 31 of the through hole 30 communicating with the liquid introduction portion 20 penetrates almost straight along the central axis L1 of the main body portion 10, the liquid flowing into the central region of the liquid introduction portion 20 is the hose 3. It flows into the central region 31 of the through hole 30 at almost the same pressure and flow velocity as when flowing through the inside. On the other hand, the liquid that has flowed into the peripheral region of the liquid introduction unit 20 collides with the side walls 21 to 24 of the liquid introduction unit 20 and is pressurized and accelerated. Therefore, also in the liquid introduction portion 20, a pressure difference occurs between the liquid flowing in the central region and the liquid flowing in the peripheral region. Therefore, even in the liquid introduction unit 20, it is considered that bubbles are generated in the liquid flowing in the central region due to the depressurizing action.

Since the side walls 21 to 24 of the liquid introduction portion 20 are formed in a spiral shape, the liquid colliding with the side walls 21 to 24 is spirally swirled and swirled in a spiral shape to the first peripheral region 32 and the second peripheral region 33 of the through hole 30. It flows in while being accelerated. At this time, a centrifugal force acts on the swirling liquid in the radial direction with respect to the central axis L1 of the main body 10, and the liquid flowing near the outer periphery of the circular opening 25 of the liquid introduction portion 20 is further pressurized. ..

Since the central region 31 of the through hole 30 includes the central axis L1 of the main body portion 10 in any cross section, as shown in FIG. 3, a liquid such as a barrier is surrounded around the central axis L1 of the main body portion 10. There is nothing that obstructs the flow of. Therefore, among the liquids that have flowed into the through hole 30, the liquid that has flowed into the central region 31 is hardly rotated, and the central axis L1 of the main body 10 has almost the same pressure and flow velocity as when it has flowed through the hose 3. It flows straight along. On the other hand, among the liquids that have flowed into the through hole 30, the liquid that has flowed into the first peripheral region 32 and the second peripheral region 33 is swirled by the action of the slopes 21 to 24 of the liquid introduction portion 20, but the through hole 30. By rotation, it is further spirally swiveled along the outer circumference of the substantially cylindrical main body portion 10. Centrifugal force acts on the swirling liquid, and the liquid flows so as to concentrate in the region of the first peripheral region 32 and the second peripheral region 33, which is farther from the central axis l1 of the main body 10. Therefore, inside the through hole 30, a pressure difference is generated between the liquid flowing through the central region 31 and the liquid flowing through the first peripheral region 32 and the second peripheral region 33, and the liquid flowing through the central region 31 due to the depressurizing action. Bubbles are generated. Further, due to the speed difference between the liquid flowing through the central region 31 of the through hole 30 and the liquid flowing through the first peripheral region 32 and the second peripheral region 33 of the through hole 30, a violent vortex is generated in the liquid flowing through the through hole 30. This also creates bubbles. Further, among the liquids flowing in the first peripheral region 32 and the second peripheral region 33, a pressure difference is generated between the liquid flowing in the region on the outer peripheral side of the main body 10 and the liquid flowing in the region close to the central axis, and the pressure is reduced. Due to the action, bubbles are also generated in the liquid flowing through the first peripheral region 32 and the second peripheral region 33.

The cross-sectional area of the second end portion 12 of the main body portion 10, that is, the through hole 30 on the side where the liquid is discharged is from the cross-sectional area of the substantially circular opening 25 of the liquid introduction portion 20 of the first end portion 11 of the main body portion 10. Is also small. Therefore, when the liquid is discharged from the second end portion of the main body portion, it is inside the shower head 2 and in the vicinity of the second end portion 12 of the main body portion 10 (for example, the portion shown by the ellipse 2A in FIG. 1). Creates a cavity that is close to a vacuum with no liquid flowing through it. Therefore, due to the negative pressure of the cavity, the air dissolved in the liquid discharged from the second end 12 of the main body 10 is foamed at once, and a large amount of fine bubbles are generated in the liquid. As described above, according to the fine bubble generator 1 according to the present invention, bubbles are generated due to various factors, so that the amount of fine bubbles generated can be increased as compared with the conventional apparatus described in, for example, Patent Document 2. Can be increased.

FIG. 6 shows the cross-sectional shape of the through hole shown in FIG. 5 (b) of Patent Document 2 as a first comparative example. The through hole 50 of the first comparative example is also divided into roughly three regions, and includes the central axis L1'of the main body portion (not shown), similarly to the through hole 30 of the fine bubble generator 1 according to the present invention. The central region 51 including the narrowest portion in the first direction (X direction) and the second direction (Y direction) orthogonal to the first direction are formed symmetrically with respect to the central axis L1'of the main body portion. It is formed by a first peripheral region 52 and a second peripheral region 53 including the widest portion in one direction.

The central region 51 has a first radius R1'that is inwardly convex with respect to the central axis L1'of the main body portion, passes through the central axis L1'of the main body portion, and has a symmetry axis L3'parallel to the second direction. It is formed by two first radial portions 51a that are symmetrically opposed to each other. The first peripheral region 52 and the second peripheral region 53 each have a second radius R2'centered on the central axis L1'of the main body portion, and each have a second radius outwardly convex with respect to the central axis L1'of the main body portion. It has two radius portions 52a and 53a and a fourth radius R4'that is larger than the first radius R1'and smaller than the second radius R2', with respect to the axis of symmetry L3'that is perpendicular to the axis of symmetry L2'. It is formed by two fourth radius portions 52b, 53b that are symmetrical and are continuous with the second radius portions 52a and 53a and are outwardly convex with respect to the central axis L1'of the main body portion. In this first comparative example, the third radius R3'and the third radius portion do not exist.

The through hole 30 of the present invention shown in FIG. 4 and the through hole 50 of the first comparative example shown in FIG. 6 are visually compared. Both have a so-called "gourd-shaped" cross section, but the maximum width W2'in the first direction (X direction) of the first peripheral region 52 and the second peripheral region 53 of the first comparative example is the present application. It is narrower than the maximum width W2 in the first direction (X direction) of the first peripheral region 32 and the second peripheral region 33 of the through hole 30 of the present invention. Therefore, as a whole, the through hole 50 of the first comparative example gives the impression of being elongated. Further, the cross-sectional areas of the first peripheral region 52 and the second peripheral region 53 of the first comparative example are clearly narrower than the cross-sectional areas of the first peripheral region 32 and the second peripheral region 33 of the through hole 30 of the present invention. Further, the minimum width W1'of the central region 51 of the first comparative example is wider than the minimum width W1 of the central region 31 of the through hole 30 of the present invention, and the cross-sectional area of the central region 51 of the first comparative example is the present invention. It is wider than the cross-sectional area of the central region 31 of the through hole 30 of. From these facts, the difference between the amount of liquid flowing through the central region 51 of the through hole 50 of the first comparative example and the amount of liquid flowing through the first peripheral region 52 and the second peripheral region 53 is the difference between the amount of liquid flowing through the through hole 30 of the present invention. It is considered to be smaller than the difference between the amount of liquid flowing through the central region 31 and the amount of liquid flowing through the first peripheral region 32 and the second peripheral region 33. In other words, as compared with the through hole 50 of the first comparative example, the through hole 30 of the present invention has the amount of liquid flowing through the central region 31 and the amount of liquid flowing through the first peripheral region 32 and the second peripheral region 33. The difference between can be made larger.

Further, the through hole 50 of the first comparative example is directly connected to the second radial portions 52b and 53b of the first peripheral region 52 and the second peripheral region 53 and the first radial portion 51a of the central region 51, and is the fourth. Since it does not have a radius portion, the ridgeline of the first radius portion 51a of the central region 51 of the through hole 50 of the first comparative example is from the ridgeline of the first radius portion 31a of the central region 31 of the through hole 30 of the present invention. It is gentle. Further, in the through hole 50 of the first comparative example, the straight line LX'connecting the central axis L1'of the main body portion and the ridgeline of the first radius portion 51a of the central region 51, the first radius portion 51a, and the fourth radius portion 52b. The area of the region 55 indicated by the enclosed hatching is the straight line LX connecting the central axis L1 of the main body portion 10 and the ridgeline of the first radius portion 31a of the central region 31 and the first radius portion 31a in the through hole 30 of the present invention. , Much smaller than the area of the region 35 indicated by the hatching surrounded by the third radius portion 32b and the fourth radius portion 32c. Therefore, among the liquids that have flowed into the first peripheral region 52 and the second peripheral region 53 of the through hole 50 of the first comparative example, they collide with the wall surfaces of the fourth radial portions 52b and 53b located at the end in the circumferential direction. The liquid flows into the central region 51 without being hindered by the first radial portion 51a of the central region 51. On the other hand, among the liquids that have flowed into the first peripheral region 32 and the second peripheral region 33 of the through hole 30 of the present invention, they collide with the wall surfaces of the fourth radial portions 32b and 33b located at the end in the circumferential direction. The liquid is shaded by the first radius portion 31a of the central region 31 when viewed from the central axis L1 of the main body portion 10, that is, the fourth radius portions 32c and 33c of the first peripheral region 32 and the second peripheral region 33. The wall surface blocks the flow, making it difficult to flow into the central region 31. From these facts, as compared with the through hole 50 of the first comparative example, the through hole 30 of the present invention has the amount of liquid flowing through the central region 31 and the liquid flowing through the first peripheral region 32 and the second peripheral region 33. The difference in quantity can be further expanded.

Further, in the through hole 30 of the present invention, the cross section perpendicular to the central axis L1 of the main body portion 10 defining the through hole 30 is along the central axis L1 direction of the main body portion 10 from the first end side 11 to the second. It continuously rotates toward the end 12 side at a constant rate. Therefore, the liquid that has flowed into the first peripheral region 32 and the second peripheral region 33 of the through hole 30 of the present invention flows from the first end portion side 11 to the second end portion 12 side while spirally swirling. Centrifugal force is applied in the radial direction to the liquid flowing while swirling with respect to the central axis L1 of the main body 10, and the liquid flowing through the first peripheral region 32 and the second peripheral region 33 of the through hole 30 is pressurized. On the other hand, the liquid that has flowed into the central region 31 of the through hole 30 flows straight along the central axis of the outside at the same pressure and flow velocity with almost no swirling. As a result, as described above, a pressure difference is generated between the liquid flowing through the central region 31 of the through hole 30 and the liquid flowing through the first peripheral region 32 and the second peripheral region 33, and bubbles are generated in the liquid due to the depressurizing action. Occur. The same applies to the first comparative example regarding these points. However, as described above, in the fine bubble generator 1 according to the present invention, the liquid introduction portion 20 is provided on the side of the first end portion 11 into which the liquid of the main body portion 10 flows, and the through hole 30 communicating with the liquid introduction portion 20 is further provided. The area of the first peripheral region 32 and the second peripheral region 33 is made much larger than the area of the central region 31, and the amount and velocity of the liquid flowing in the first peripheral region 32 and the second peripheral region 33 are set to the central region 31. Since it can be made much higher than the amount and speed of the liquid flowing into the main body portion 10, many fine bubbles can be generated in the liquid discharged from the second end portion 12 side of the main body portion 10.

On the other hand, in the device of the first comparative example, the liquid introduction portion is not provided at the end of the main body portion (not shown) on the side where the liquid flows, and the liquid directly flows into the through hole 50, so that the main body portion It is considered that the absolute amount of the liquid flowing through the through hole 50 is also reduced because the end face of the water is obstructed by obstructing the flow of the liquid and the state is similar to that of the faucet being squeezed. Further, the areas of the first peripheral region 52 and the second peripheral region 53 of the through hole 50 of the first comparative example are not so large with respect to the area of the central region 51, and flow into the first peripheral region 52 and the second peripheral region 53. The amount and velocity of the liquid cannot be much higher than the amount and velocity of the liquid flowing in the central area 51. Therefore, the amount of fine bubbles contained in the liquid discharged from the main body portion is smaller than that of the fine bubble device of the present invention.

In order to numerically compare the dimensions of the through hole 50 of the through hole 30 of the present invention shown in FIG. 4 and the through hole 50 of the first comparative example shown in FIG. 6, the through holes 30 and 50 on the axes of symmetry L3 and L3' The length of each opening was set to 10 mm. In the specific example shown in FIG. 4, R1 = 2.0 mm, R2 = 5.0 mm, R3 = 2.3 mm, R4 = 1.0 mm, W1 = 0.8 mm, W2 = 6.4 mm, W1: W2 = 1: 8, R1: R2 = 1: 2.5. On the other hand, in the first comparative example shown in FIG. 6, R1'= 2.0 mm, R2'= 2.8 mm, R4'= 1.6 mm, W1'= 1.3 mm, W2'= 4.6 mm, W1': W2'≈1: 3.5, R1': R2'= 1: 1.4. It is summarized in Table 1 for easy comparison.

FIG. 7 shows the cross-sectional shape of the through hole shown in FIG. 5 (d) of Patent Document 2 as a second comparative example. Similar to the through hole 30 of the fine bubble generator 1 according to the present invention, the through hole 60 of the second comparative example is also divided into roughly three regions and includes the central axis L1 of the main body portion (not shown). The central region 61 including the narrowest portion in the first direction (X direction) is formed symmetrically with respect to the central axis L1 "of the main body portion in the second direction (Y direction) orthogonal to the first direction. It is formed by a first peripheral region 62 and a second peripheral region 63 including the widest portion in one direction.

However, as described in paragraph [0033] of the specification of Patent Document 2, the portions 62a and 63a of the first peripheral region 62 and the second peripheral region 63 that should correspond to the second radius portion are parallel to the circumference. Instead, it is formed on a straight line. Therefore, no centrifugal force acts on the liquid flowing through the first peripheral region 62 and the second peripheral region 63, and the liquid is not pressurized. Therefore, it is not necessary to make a detailed comparison with the through hole 30 of the present invention, and the pressure difference between the liquid flowing through the first peripheral region 62 and the second peripheral region 63 and the liquid flowing through the central region 61 of the through hole 60 of the second comparative example. Is small and the amount of fine bubbles generated is small.

Next, a first modification of the through hole 30 of the fine bubble generator according to the present invention will be examined. The minimum width W1 of the central region 31 of the through hole 30 is a portion of the mold for molding the main body 10 that forms the central axis of the inner mold that is pulled out while rotating. Considering the strength and processing technology, It cannot be made too small. Therefore, we fixed the numerical values other than the maximum width W2 and examined how far the maximum width W2 could be expanded. In FIG. 8, the third radius portions 32b and 33b and the fourth radius portions 32c and 33c in the first peripheral region 32 and the second peripheral region 33 of the through hole 30 overlap each other, and the third radial portions 32b and 33b are substantially eliminated. Show the limit to do. In this case, the maximum width W2 = 7.4 mm and W1: W2 = 1: 9.25. In order to further expand the maximum width W2, it is necessary to further reduce the fourth radius R4 of the fourth radius portions 32c and 33c, and further curve between the first radius portion 31a and the fourth radius portions 32c and 33c. It is necessary to provide a part. Considering the strength of the mold and the processing technology, it is considered unlikely to be feasible.

Next, a second modification of the through hole 30 of the fine bubble generator according to the present invention will be examined. Based on the first comparative example shown in FIG. 6, the minimum width W1'of the central region 51 of the through hole 50 is set to the same dimension as the minimum width W1 (not shown for obvious reasons). In this case, the area of the central region 51 of the through hole 50 is narrowed, and the areas of the first peripheral region 52 and the second peripheral region 53 are increased by that amount. Therefore, as compared with the first comparative example, the amount of liquid flowing in the central region 51 of the through hole 50 is small, and the amount of liquid flowing in the first peripheral region 52 and the second peripheral region 53 is increased. The pressure difference between the pressure of the liquid flowing in the central region 51 and the pressure of the liquid flowing in the first peripheral region 52 and the second peripheral region 53 becomes large, and the amount of fine bubbles generated increases. Further, by providing the bowl-shaped liquid introduction portion 20 on the side of the first end portion 11 of the main body portion 10 into which the liquid flows, a large amount of fine bubbles can be generated as compared with the first comparative example.

Next, the number of nanobubbles in tap water through the three prototypes by the applicant and the three comparative products by the patentee of Patent Document 2 and the number of nanobubbles in tap water without using these fine bubble generators are measured. did. Since the length, inner diameter (maximum dimension of through hole), number of rotation angles of through hole, etc. of the fine bubble generator (main body) are not unified, direct comparison cannot be made, but the measurement results are shown. At the time of measurement, the water pressure was set to 0.16 MPa, and a measuring device by a laser analysis method sold by Shimadzu Corporation and the like was used. The measurement results are shown in Table 3.

Comparing the measurement results of the comparative product 3 and the invention product 3 of the present application, it can be seen that the product 3 of the present application generates the same number of nanobubbles as the comparative product 3 even though the total length of the apparatus is 1/2. Further, when comparing the comparative product 1 and the comparative product 2 and the present invention product 1 and the present invention product 2, it can be seen that the larger the rotation angle of the through hole, the more nanobubbles are generated. From these measurement results, it can be seen that the fine bubble generator according to the present invention is improved as compared with the conventional fine bubble generator described in Patent Document 2 and can generate more fine bubbles.

1 Fine bubble generator 2 Shower head 3 Hose 10 Main body 11 1st end 12 2nd end 20 Liquid introduction 21 to 24 Slope 25 Circular opening 30 Through hole 31 Central area 31a 1st radius 32 1st periphery Area 32a 2nd radius 32b 3rd radius 32c 4th radius 33 2nd peripheral area 33a 2nd radius 33b 3rd radius 33c 4th radius 34 slope

Claims (4)

A through hole that communicates with the main body portion having a substantially cylindrical outer shape, a liquid introduction portion formed at the first end portion on the side where the liquid flows in, and the liquid introduction portion, and penetrates the main body portion in the direction of the central axis thereof. And with
The liquid introduction portion has a substantially circular opening at the first end portion of the main body portion, and is opposite to the first end portion of the main body portion in a predetermined cross section including the central axis of the main body portion. It is formed so that the cross-sectional area gradually decreases toward the second end of the
In any cross section perpendicular to the central axis of the body, the through hole comprises the central axis of the body and is orthogonal to the central region including the narrowest portion in the first direction. It is formed symmetrically with respect to the central axis of the main body in the second direction, and is formed by a first peripheral region and a second peripheral region including the widest portion in the first direction. The first peripheral region and the second peripheral region are communicated by a continuous curve having no corners.
Any cross section perpendicular to the central axis of the main body defining the through hole is at least 270 degrees from the first end side toward the second end side along the central axis direction of the main body. It's spinning ,
In any cross section perpendicular to the central axis of the body
The central region has a first radius that is inwardly convex with respect to the central axis of the main body, passes through the central axis of the main body, and is symmetrically opposed to the axis of symmetry parallel to the second direction. Formed by two first radii,
The first peripheral region and the second peripheral region each have a second radius centered on the central axis of the main body portion, and have a second radius portion that is outwardly convex with respect to the central axis of the main body portion. On the central axis of the main body, which has a third radius larger than the first radius and smaller than the second radius, is symmetric with respect to the axis of symmetry, and is continuous with the second radius. It has two outwardly convex third radii and a fourth radius smaller than the first radius, is symmetrical with respect to the axis of symmetry, and is continuous with the third radius and the first radius. It is formed by two fourth radial portions that are convex outward with respect to the central axis of the main body portion.
A fine bubble generator characterized by this. A through hole that communicates with the main body portion having a substantially cylindrical outer shape, a liquid introduction portion formed at the first end portion on the side where the liquid flows in, and the liquid introduction portion, and penetrates the main body portion in the direction of the central axis thereof. And with
The liquid introduction portion has a substantially circular opening at the first end portion of the main body portion, and is opposite to the first end portion of the main body portion in a predetermined cross section including the central axis of the main body portion. It is formed so that the cross-sectional area gradually decreases toward the second end of the
In any cross section perpendicular to the central axis of the body, the through hole comprises the central axis of the body and is orthogonal to the central region including the narrowest portion in the first direction. It is formed symmetrically with respect to the central axis of the main body in the second direction, and is formed by a first peripheral region and a second peripheral region including the widest portion in the first direction. The first peripheral region and the second peripheral region are communicated by a continuous curve having no corners.
Any cross section perpendicular to the central axis of the main body defining the through hole is at least 270 degrees from the first end side toward the second end side along the central axis direction of the main body. It's spinning,
In any cross section perpendicular to the central axis of the body
The central region has a first radius that is inwardly convex with respect to the central axis of the main body, passes through the central axis of the main body, and is symmetrically opposed to the axis of symmetry parallel to the second direction. Formed by two first radii,
The first peripheral region and the second peripheral region each have a second radius centered on the central axis of the main body portion, and have a second radius portion that is outwardly convex with respect to the central axis of the main body portion. , Which has a fourth radius smaller than the first radius, is symmetric with respect to the axis of symmetry, and is continuous with the first radius portion and the second radius portion, and is outward with respect to the central axis of the main body portion. It is formed by two convex fourth radii,
The ratio W1: W2 of the dimension W1 of the narrowest portion of the central region in the first direction and the dimension W2 of the widest portion of the first peripheral region and the second peripheral region in the first direction is , 1: 5.75 to 1: 9.25,
The ratio R1: R2 of the radius R1 of the first radius portion and the radius R2 of the second radius portion is 1: 2.5.
A fine bubble generator characterized by this . The fine bubble generation according to claim 1 or 2, wherein the liquid introduction portion is formed in a continuous curved shape having no corners in a predetermined cross section including the central axis of the main body portion. Device. The ratio of the dimension of the narrowest portion of the central region in the first direction to the dimension of the widest portion of the first peripheral region and the second peripheral region in the first direction is 1: 5. The fine bubble generator according to claim 1, wherein the fine bubble generator is in the range of 75 to 1: 9.25 .

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