JP7571938B2 - Fine bubble generator - Google Patents

Description

The present invention relates to a component or device for generating fine bubbles in a liquid.

In recent years, technology that utilizes tiny bubbles in liquids has been attracting attention. These tiny bubbles in liquids were previously classified according to their size as millibubbles/submillibubbles, microbubbles, ultrafine bubbles, etc., but now both microbubbles and ultrafine bubbles are defined as fine bubbles.

Millimeter/submillimeter bubbles range in diameter from about 100 μm in water (about the diameter of a hair) to even larger bubbles, and are visible to the naked eye. For example, a bubble with a diameter of 1 mm (1,000 μm) rises in water at a speed of about 5 to 6 m/min, and bursts and disappears when it reaches the water surface; it rises quickly and disappears quickly.

Next, in the case of water containing bubbles that were previously classified as microbubbles, the first category of bubbles defined as fine bubbles are those with a diameter in the range of about 1 μm to 100 μm, and the bubbles can be seen in the water as a cloudy white liquid, and they rise very slowly; for example, a bubble with a diameter of 10 μm rises at a slow speed of 3 mm/min in water at room temperature, shrinking and completely dissolving in the water before disappearing.

The second type of fine bubbles, previously classified as ultrafine bubbles, have a diameter of several tens of nanometers to 1 μm. Also known as nanobubbles, these bubbles are colorless and transparent in water, making them impossible to see with the naked eye. These bubbles, which are invisible to the naked eye but do exist, have a high viscosity and continue to vibrate minutely rather than floating in water, and have a life span of several weeks to several months in water, so they do not disappear immediately.

The present invention defines these micro-sized bubbles, called "microbubbles," and nano-sized bubbles, called "ultrafine bubbles" (previously called "nanobubbles"), as "fine bubbles," and aims to make it easier to manufacture and use a bubble generator that generates fine bubbles by attaching it to a water faucet or midway through a water pipe, so that tiny bubbles can be easily introduced into the water supply pipe when water is being supplied.

JP 2004-33962 A JP 2017-225908 A JP 2018-111197 A

As explained in the background art, if both microbubbles and ultrafine bubbles are defined as fine bubbles, generators that generate fine bubbles midway through a flow path can be broadly divided into the "single-axis serial flow generation method" shown in Patent Document 1, in which bubbles are generated by a generator with only one axis in the axial direction.

Next, there is a "parallel two-axial flow generating system" shown in Patent Document 2, in which a flow path is branched into two rows in the axial direction and a generator is provided in each row to generate flow.
Furthermore, Patent Document 3 discloses a "serial dual axial flow generation system" in which a dual shaft is used and a generator is provided around each shaft.

In this type of conventional fine bubble generation method, which uses a generator with only one axis in the axial flow direction (serial single axial flow generation method), components on the inlet and outlet lids are required for the axial length of the generator, so the overall axial length of the generator is determined to a certain extent.
For example, if one considers the case where the generator of the present invention is retrofitted to an existing water faucet for hand washing, unless the overall length of the generator is kept small, the water outlet will be too low, and the user will have to bend over when washing their hands, which will be tiring.

Next, in the "parallel two-axial flow generation method" in which the flow path is branched into two rows in the axial direction and a generator is provided in each row, the effective length of the generator part increases by the amount of parallelization, and this can be shortened by that amount, which is an improvement over Patent Document 1 in that it shortens the overall length of the generator.
In addition, the "serial dual axial flow generation method" shown in Patent Document 3, which uses dual shafts and has a generator around each shaft, also increases the effective length of the generator part by the amount of the dual shafts, making it possible to shorten the overall length of the generator.

However, in the "parallel dual axial flow generation method" and "serial dual axial flow generation method," the effective length of the generator portion is at most twice as long, and further improvements are required to shorten the axial length of the generator. The present invention improves on this point, and describes a configuration that is believed to improve the ability to generate fine bubbles, rather than reducing the protruding length in the water flow direction as much as possible.

Conventional fine bubble generators aim to improve bubble generation performance by inserting a generator that is either single-axis, two parallel axes, or double-axis.
In the present invention, the vessel is simply a "hollow vessel" with an inlet and outlet for running water; when nothing is attached to it, it becomes a "flow path with an expansion chamber." When the generator blades and the reversing flow path tray, which are part of the fine bubble generator, are inserted into this chamber, it becomes a "fine bubble generator."

The fine bubble generator blade is made of a single circular plate, and multiple blades are combined into a laminated "fine bubble blade group." This blade group has not only one flow path but multiple flow paths, and has a shape that can be easily assembled.
In other words, when used as a group of blades, the structure is characterized by having a coaxial "input flow passage" in the forward direction on the first axis, a "reverse flow passage" that reverses in the opposite direction on the second axis, and an "outlet flow passage" in the forward direction on the third axis.

In the present invention, the flow paths provided within the "fine bubble blade group" are the "input flow path" in the forward direction of the first axis, the "reverse flow path" of the second axis, and the "outlet flow path" in the forward direction of the third axis, which are all arranged coaxially. Therefore, by simply inserting and attaching the "fine bubble blade group" and the "receiving tray for the reverse flow path" into a "hollow container" where liquid flows only in the forward direction, the flow path changes from the "forward flow path" to the "reverse flow path" and then back to the "forward flow path", and the same effect can be achieved with a shorter axis as with a short-axis or double-axis fine bubble generator with a longer axis.

In addition, the fine bubble generating blade is a single circular plate that is stacked to form the fine bubble generator blade, so if the thickness of the single blade is halved, twice as many fine bubble generator blades can be stored in the expansion chamber arranged in the "hollow container body," and if it is halved, three times as many fine bubble generator blades can be stored.

When a single blade, which is a single circular plate, is machined to form a group of bubble generating sections, each of which has multiple bubble generating sections in one stage, on the circumferential portion of each flow path of the single blade, as the shape of the bubble generating section and the group of bubble generating sections is changed from large to small, the thickness of the single blade can also be changed automatically and proportionally, making it easy to set the shape of the bubble generating section.
In other words, when the performance of the bubble generating part changes during the course of research, it is easy to always track down the optimal shape of the bubble generating part.

FIG. 1 is an overall cross-sectional side view of a first embodiment. FIG. 2 is an exploded explanatory overall view showing the main parts of the members shown in FIG. 1 . FIG. 2 is an oblique view of the fine bubble blade, a main component of the present invention, viewed from the upstream side. FIG. 13 is an oblique view of the fine bubble blade, another main component, viewed from the downstream side. It is a hollow container for storing stacked main parts. FIG. 13 is an oblique view of the main component, a fine bubble blade, of another example, viewed from the upstream side. FIG. 11 is an oblique view of another example of the fine bubble blade as viewed from the downstream side. FIG. 4 is a second example (modified example) of the main part of FIG. 3. Similarly, FIG. 6 shows a second example (modified example) of the main part. FIG. 1 is an explanatory diagram of the standard arrangement of fine bubble blades (triangular cross section). FIG. 13 is an explanatory diagram of a modified arrangement of fine bubble blades (triangular cross section).

In short, as shown in Figure 5, a simple "hollow container body" (A) with an inlet and outlet for running water is used as a "flow path with an extension chamber" when nothing is attached to it. In this extension chamber, a group of blades is formed by stacking multiple fine bubble generating blades, each of which is the fine bubble generating device shown in Figures 1 and 2, and this group of blades, the fine bubble generator blades (4) and the reversing flow path receiver (11), are inserted and attached to form a "fine bubble generator" (5), thereby simply and easily providing a fine bubble generator in a running water path. Below, an embodiment of the present invention will be described based on the drawings.
It should be noted that the following embodiment and description are merely examples of the present invention and do not limit the technical scope of the present invention.

The flow path will be described by taking a flow path for tap water as an example, and the configuration of the overall cross-sectional side view in FIG.
First, the structure will be described. As shown in Fig. 5, a large-diameter cylinder (10) having a discharge passage (2) is closed with a lid (12) having an inlet passage (1), and the two together form a "hollow container body" (A). (16) is an O-ring, which is attached to prevent water from leaking to the outside through the threads (17).

The inlet passage (1) has a male thread portion (15) on its outer periphery. When a water hose or faucet (not shown) is attached to this and water is turned on, the water flows into the container and out of the outlet passage (2).
In this state, it is merely a "hollow vessel body" (A) having a "flow path with an expansion chamber." Therefore, the entire assembly, which is assembled to form fine bubble generator blades (4) consisting of multiple stacked individual blades (8), which will be described next, for generating fine bubbles, is inserted and fixed into the mounting hole (13) of the large-diameter cylindrical body (10), which is the expansion chamber portion.

As shown in Figure 3, the individual blade (8) is a disk-shaped plate of a predetermined thickness (H), and has three flow paths in the single blade (8): a central passage hole (3) for the inflow water to pass through, a reverse flow path (9) which is a water passage hole for the primary fine bubble blade group (6), (6)... which is provided on the outer periphery, and a forward flow path (14) which is a water passage hole for the secondary fine bubble blade group (7), (7)... which is further provided on the outer periphery.

The outer circumference of each flow path is provided with an outer peripheral wall that separates the flow path. The passage hole (3) through which the inflow water passes has an inner peripheral wall (3a) on the outer circumference, the reverse flow path (9) which is the water passage hole of the primary fine bubble blade group (6), (6) ... has a blade group outer peripheral wall (6a) on the outer circumference, and the forward flow path (14) which is the water passage hole of the secondary fine bubble blade group (7), (7) ... provided on the outer circumference has a maximum diameter peripheral wall (7a) on the outer circumference.

The disc-shaped single blade (8) has a predetermined thickness (H), and the thickness between the upper and lower surfaces of each peripheral wall is set to the same dimension to maintain uniform flatness.
Then, about 15 of these individual blades (8) are stacked in layers as shown in the fine bubble generator blade (4) in Figures 1 and 2, and after the inverted flow path tray (11) is inserted into the large diameter cylindrical body (10), the fine bubble generator blade (4) is attached to the mounting hole (13) of the cylindrical body so that the maximum diameter peripheral wall (7a) of the individual blade (8) is in contact with it.

As a result, as shown in FIG. 1, the direction of flow of water that enters through the inlet channel (1) and passes through the passage hole (3) is blocked by the inner guide surface (11a) of the reversing flow channel tray (11), and since the circular end surface (18) of the tray (11) is in contact with the outer peripheral wall (6a) of the blade group, the water flows into the reversing flow channels (9) of the primary fine bubble blade groups (6), (6), ...
Furthermore, the water that has flowed into the reverse flow path (9) flows to the lid body (12) while generating fine bubbles as it passes through the primary fine bubble blade groups (6), (6).

Referring mainly to Figures 1 and 2, the cover body (12) is provided with a circular rib on its inner peripheral end face (19) around the inflow passage (1) and on its outer peripheral end face (20) which presses against the maximum diameter peripheral wall (7a) on the fine bubble generator blade (4) side, and the rib height has inner and outer flatness dimensions controlled, and comes into contact with the hole inner peripheral wall (3a) and maximum diameter peripheral wall (7a) of the individual blade (8).
By tightening the threads (17) of the cover body (12), the fine bubble generator blades (4) are attached to the mounting holes (13) of the large diameter cylindrical body (10) and their movement is restricted by the restricting surfaces (21), and apply pressure to the front and rear surfaces in the direction of water inflow, separating and maintaining the flow paths of the three flow paths mentioned above.

The water that reaches the inside of the lid (12) is pushed from the inner peripheral end face (19) toward the outer peripheral end face (20) and flows into the forward flow path (14).
A plurality of secondary fine bubble blade groups (7), (7) ... are provided in the forward flow path (14), and further fine bubbles are added to the water flowing through the forward flow path (14).
The water that has passed through the forward flow path (14) passes between the four support legs (22) of the tray (11) and exits the device through the outflow path (2).

In the present invention, as described above, a hollow vessel body (A) is attached midway through the water flow path, and when nothing is inserted and attached, it is used simply as a flow path connector.
A fine bubble generator can be easily created by attaching a fine bubble generator blade (4) consisting of a plurality of stacked individual blades (8) and a reversal flow path tray (11) to the large diameter cylindrical body (10) of the container body.
Furthermore, the component constituting the fine bubble generator blade (4) is an aggregate of a single blade (8), which can be procured at low cost.

Furthermore, since the single blade (8) has three flow paths in one component, namely the passage hole (3), the reverse flow path (9), and the forward flow path (14), the axial length in the overall length direction can be shortened simply.
In addition, the overall performance of the fine bubble production machine can be easily changed by rearranging the internal configuration of the three flow paths.

Although the fine bubble production performance was not clearly stated, it may be a reticulated diamond-shaped convex portion as shown in each patent document cited in the prior art document, or, although not cited, a triangular convex portion or a swastika-shaped plate may also be used; it is not particularly specified as long as it has a configuration that generates fine bubbles.
The present application relates to a single blade (8) having a fine bubble generating unit attached to one of three flow paths,
Next, we will explain how to simply and easily assemble and polymerize unitary blades (8) of the same shape to complete the blade (4) for a fine bubble generator.

In the peripheral wall of the individual blade (8), a protrusion (23) is provided between the fine bubble blades on the inner peripheral wall of the hole (3a) in the perspective view from the upstream side in Fig. 3, and a recess (24) is provided in the inner peripheral wall of the hole (3a) at approximately the same location as the central protruding edge (6b) of one of the fine bubble blades in the perspective view from the downstream side in Fig. 4. When the protrusion (23) and the recess (24) are engaged, the fine bubble blade provided in the reversal flow path (9) of the individual blade (8) is shifted by half a blade at a time.

The standard 1/2 offset arrangement of fine bubble impellers (triangular cross section) shown in Figure 10 is explained using an explanatory diagram. In this arrangement, the central edge of the next stage single impeller is offset by 1/2 with respect to the water flow.
For example, in the case of a reverse flow path (9) with a water flow from the lower side in the figure, the water flow (27) that has flowed between the blades (6)-(6) of the primary fine bubble blade group (6)-(6) of the first individual blade (8) and the adjacent water flow (28) will flow into the second row of individual blades (8a).
The water flow (27) flowing into the fine bubble blade group central flange (60b) provided on the blades (60) of the primary fine bubble blade group (6), (6), ... provided on the second single blade (8a) is divided into two equal parts on the left and right by the central flange (60b), into a rightward water flow (27R) and a leftward water flow (27L).

Similarly, the adjacent water flow (28) also flows into the central flange (60b) of the fine bubble blade group. The adjacent water flow (28) is roughly divided into two at the central flange, a water flow (28R) to the right and a water flow (28L) to the left.
In this way, the water flow hits all of the primary fine bubble blade groups (6), (6) ... (60), (60) ... and is diverted in almost equal amounts to the left and right at the central edges (6b) and (60b) of each fine bubble blade group, and the diverted water flow again flows into the next third single blade (8b). Thus, in the case of 1/2 offset, the water flow has a certain degree of directionality.

The arrangement of fine bubble blades (triangular cross section) shown in Fig. 11 (another example) is explained using an explanatory diagram. In this example, the central edge of the next stage blade is shifted by 1/4 with respect to the water flow.
In other words, the water flow (27) in the figure is shifted by 1/4 of the distance in the width direction, i.e., the shift width (S) indicated by the symbol S, from the fine bubble blade group central flange (60b) provided on the blades (60) of the primary fine bubble blade group (6), (6) ... provided on the second single blade (8a).

For this reason, the water flow (27) flowing between the primary fine bubble blade groups (6) of the first single blade (8) tends to flow as a large water current (27a) downward along the oblique slope of the blade (60).
The water flowing in the direction of the small water flow (27b) is unlikely to flow unless it overcomes the central flange (60b) of the fine bubble blade group, so the amount of diverted water is simply reduced.

Furthermore, the large water flow (27a) comes into contact with the inclined surface of the blade (70) of the third stage of single blades (8b), and changes its water flow direction along the inclined surface toward the next large water flow (70a).
Then, the water flows in a large stream (80a) along the inclined surface of the blade (80) of the stage of the fourth single blade (8c) and travels in an approximately straight line.

Similarly, the adjacent water flow (28) flowing between the primary fine bubble blade groups (6) (6) of the first single blade (8) also tends to flow downward along the oblique slope of the blade (60) as a large water flow (28a) and then travels straight downward as an adjacent reverse large water flow (70b).
Eventually, the neighboring large water current (70b) in the opposite direction collides with the next large water current (70a) and the next large water current (80a) and so on, and the blades (80) (80) of the fourth single blade (8c)... After that, it is left to its own devices and flows towards the side with lower flow pressure, after repeated collisions.

When the water currents collide, small air bubbles are generated in the water current at each corner of the surrounding blades, and the direction and strength of the water current can be changed in any way by changing the shape of the blades and the amount of deviation of the blades.
In other words, by stacking individual blades, when testing the blade shape, it is possible to inexpensively manufacture products with many variations, such as using a stack of blades of the same shape, using blades of the same shape to increase the change in the amount of deviation, or incorporating partial changes to the shape of stacked blades.

The relationship between the protrusions (23) and recesses (24) of the individual blades (8) is such that when assembling the individual blades (8), the blades can be polymerized simply by deciding the insertion direction (upper or lower surface) of the individual blades (8) relative to the axis of the reference jig and throwing them in. Thereafter, by turning the portion of the maximum diameter peripheral wall (7a) located at the upper end, the protrusions (23) and recesses (24) will engage due to their own weight, making it possible to assemble a laminate of blades (4) for fine bubble generators without any special technique.
In other words, even a person with little experience can assemble the main parts easily, which helps reduce the number of assembly steps.

In addition, by utilizing the misalignment of the blades, the air in the running water is broken down into fine bubbles, thereby creating a fine bubble manufacturing device that contains fine bubbles in the running water. The action and effect of this bubble manufacturing device overlaps with the explanation of Figures 10 and 11, so details will be omitted.
Simply put, the water flowing from the gap between the blades is directed at the center of the next blade, where it is diverted again along the blade shape, and air bubbles are generated by the rear end shape or corners of the blade, which then hit the next downstream blade, and this process is repeated.

6 and 7, a fine bubble blade group having a different configuration will be described.
The positions of the three flow paths and the positional relationship between the protrusions (23) and recesses (24) required for stacking the individual blades (8) remain unchanged, but the shape of the blade group is different in that the blades in Figures 3 and 4 have a triangular blade cross section at the point where the diameters are equal in the circumferential direction, whereas the blade of the second individual blade (80) having a different configuration has a diamond-shaped blade group cross section at the point where the diameters are equal in the circumferential direction.

This difference in shape will be explained in terms of the flow of water from the upstream direction relative to the passage hole (3) in Figure 6. When the water flowing downward through the passage hole (3) reverses and flows upward from the reversing flow path (9), the diamond-shaped slope (25) of the blade causes the water flow to become a swirling direction-specified flow (26) that rotates counterclockwise when viewed from below in the reversing flow path (9).
In other words, when the reversing flow path (9) is viewed from the downstream side as shown in FIG. 7, the water flows while rotating counterclockwise.

With a diamond-shaped blade cross section, the water flow direction is determined at the initial design stage.
When the blade group has a triangular cross section as shown in Figures 3 and 4, the water flow splits into two directions due to resistance at the destination, and flows in the direction of least resistance.
In this way, the direction of the water flow changes depending on the shape of the blade cross section.

The third individual blade (81) shown in Figure 8 has a configuration in which the maximum diameter peripheral wall (7a) of the individual blade (8) shown in Figure 3 has been removed, and differs in that the secondary fine bubble blade groups (7), (7)... are directly visible. However, after assembly as the fine bubble generator (5), the mounting hole (13) of the large diameter cylinder (10) acts as the peripheral wall of the outer periphery, so there is no particular difference in the configuration or effect.

In addition, if the large-diameter cylinder (10) is made of a transparent material, the water flow in the forward flow path (14) at the outermost periphery can be directly confirmed, and as a fine bubble generator blade (4), it is possible to determine whether air bubbles in the forward flow path (14) are millibubbles, microbubbles, or ultrafine bubbles based on the size and color of the bubbles, making performance improvement tests easier.

Furthermore, if the large-diameter cylindrical body (10) and the fine bubble generator blades (4) are also made of transparent materials, the fine bubble generation performance of all three flow paths, i.e., the passage hole (3), the reverse flow path (9), and the outermost forward flow path (14), can be confirmed.
Furthermore, by making part of the transparent member a special color such as black, red, or yellow, the generation of air bubbles in each flow path can be made clearly or hidden, allowing for visually unexpected uses.

The present invention is characterized by having three or more flow paths. For example, by arranging a spiral or the like in the through hole (3), which is the first flow path, and over-rotating the inflowing water from the beginning, the fine bubble production performance of the primary fine bubble blade group (6) installed in the second reversing flow path (9) and the secondary fine bubble blade group (7) installed in the third flow path will change.
Furthermore, various configurations are possible, such as providing an odd number of flow passages, such as five flow passages or seven flow passages, in the single blade (8) to shorten the overall length in the thickness direction.

1 Inflow duct 2 Outflow duct
3 Passing hole 3a Hole inner peripheral wall
4 Fine bubble generator blade 5 Fine bubble generator
6 Primary fine bubble blade group 6a Blade group outer wall 6b Fine bubble blade group central flange 7 Secondary fine bubble blade group
7a Maximum diameter wall 8 Single blade
8a: second single blade; 8b: third single blade; 8c: fourth single blade; 9: reverse flow passage
10 Large diameter cylinder 11 Reversal flow path tray
11a Inner guide surface 12 Lid body
13 Mounting hole 14 Forward flow path
15 Male thread portion 16 O-ring
17 Between the threads 18 Circular end surface
19 Inner peripheral end surface 20 Outer peripheral end surface
21 Regulating surface 22 Support leg
23 Protrusion 24 Recess
25 Diamond-shaped slope 26 Swirling flow
27 Water flow 27a Large water current
27b Small water flow 28 Neighboring water flow
28a Water current 60 Feather
60b central flange 70 blade
70a Next current 70b Next current in the opposite direction
80 Second single blade 80a Successive large water currents
81 Third single blade A Hollow container body
H: specified thickness S: shift width

Claims (1)

The water flow direction of the inlet channel (1) and the water flow direction of the outlet channel (2) are opened coaxially in the extension direction , and the intermediate portion is a hollow container body (A) with an attachment hole (13) at least larger in diameter than the inlet channel (1), forming a "channel with an expansion chamber" ;
The fine bubble generator is characterized in that the fine bubble generator blade (4) and the reversing flow path tray (11) are detachably attached to the mounting hole (13), thereby forming a water flow path of the hollow vessel body (A) and a water flow path with the fine bubble generator blade (4) .