KR101406268B1 - Tiny bubble generator - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microbubble generator, and more particularly, to an apparatus for generating microbubbles by a hydrodynamic method. The micro-bubble generating device includes mixed fluid generating means for generating a gas-liquid mixed fluid; And a fine bubble generating means for generating fine bubbles from the mixed fluid. The fine bubble generating means is characterized in that a plurality of tubular reactors, which are tapered from a large diameter portion to a small diameter portion, . According to the apparatus, fine bubbles can be generated continuously and stably, and bubbles generated by nanoizing the size of the fine bubbles can be maintained in the liquid for a long time.

Description

[0001] TINY BUBBLE GENERATOR [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microbubble generator, and more particularly, to an apparatus for generating microbubbles by a hydrodynamic method.

Micro-bubble micro-bubbles and nano-bubbles refer to very small-sized bubbles each having approximately 10 to 50 μm and 200 nm diameter. These micro bubbles are applied to various application fields. For example, micro-bubble technology has been applied to advanced oxidation processes or advanced oxidation technologies, and cosmetics for everyday skin cleansing, and has already been commercialized and on the market. Thus, the development of a device for generating microbubbles is a very important technology in the present and near future.

Conventionally, four types of micro bubbles have been proposed as the generation methods in principle. In other words, based on the micro-bubble generation method, it can be expressed by an acoustic mode, a hydrodynamic mode, an optical mode, and a particle cavitation mode. Among them, the sonic method is a method of irradiating an ultrasonic wave to a fluid, and the hydrodynamic method is a method of generating minute bubbles by inducing a pressure change in a flowing fluid. Both of these methods can cause physical chemical changes in the fluid, but the two methods described below (i.e., optical method and particle method) do not cause any change in the fluid. The sonic and hydrodynamic methods also have characteristics with locally high energy densities leading to extreme high temperatures and pressures. Generally, the generation of micro-bubbles by using a sonic wave and a hydrodynamic method is very effective, and a sound wave system requires a considerable amount of energy. On the other hand, the hydrodynamic micro-bubble generation method can effectively form micro-bubbles without requiring additional energy cost. That is, it is possible to easily generate actual minute bubbles by inducing an appropriate pressure change in the flowing fluid. Therefore, many methods of generating micro bubbles considering the hydrodynamic method have been proposed.

However, the conventional micro-bubble generation method using the hydrodynamic method is not only difficult to obtain continuous micro-bubbles, but also can not maintain the stability of the produced micro-bubbles. In addition, the generation of minute bubbles through a porous body having a large number of fine pores or an air diffusing pipe by the above method leads to frequent failure of the pump for transferring the fluid accompanied by a large pressure loss, There is a problem that the operation is stopped frequently.

As shown in FIG. 1, the conventional method of generating micro-bubbles in the conventional hydrodynamic method is a method of generating micro-bubbles by flowing into the pump 20 through the inlet 22 according to the operation of the pump 20 (Air or the like) is converted into a mixed fluid by the operation of the impeller 21 in the pump 20 and is discharged to the outside through the discharge port 23 provided on the side surface of the pump 20. In this case, the gas distributed in the mixed fluid continuously accumulates in the pump 20, causing an excessive cavitation phenomenon, which may cause the pump 20 to fail. Also, the pump 20 The pump 20 is idle and the operation of the pump 20 is interrupted due to overheating of the pump 20 due to excessive idling, which causes the operation of the pump 20 to be inconsistent. Thus, it is often the case that continuous bubbling of a nano-micro sized micro bubble generator is not possible. As a result, the conventional micro-bubble generating apparatus has a disadvantage in that continuous micro-bubbles are not generated due to insufficient continuity of pump operation due to excessive accumulation of gas.

On the other hand, Korean Patent No. 10-0824714 discloses a micro-bubble generating device composed of an orifice and a multistage wire net, but it is difficult to continuously operate the device as described above, in which the pump discharges the mixed water. In addition, micro-sized bubbles can be generated due to the structure of the micro-bubble generating micro-bubbles, but it is difficult to generate bubbles of nano-sized size. Therefore, as the size of the bubbles increases, the micro-bubbles generated in a short period of time There is also a limitation in that the bubbles remain in the water for the required time.

It is an object of the present invention to provide a fine bubble generator capable of continuously and stably generating minute bubbles.

It is also an object of the present invention to provide a fine bubble generating device in which bubbles generated by nano-size the size of fine bubbles can be held in the liquid for a long time.

As a result of repeatedly examining and experimenting on a number of cases, the present inventor has found that, in a process of mixing and discharging a gas and a fluid of a micro-bubble generator, the mixed gas remains in the mixed fluid- The present invention has been accomplished in the process of finding a method of suppressing the residual gas mixture while seeking a method of generating nano-sized microbubbles in the microbubble generator.

In accordance with the above-mentioned problems, the present invention provides a mixed fluid producing device for producing a mixed fluid of gas and liquid; Wherein the fine bubble generating means comprises a plurality of tubular reactors each of which is tapered from a large diameter portion to a small diameter portion in a flow direction of a cross section in a flow direction of the fluid, The micro bubble generating device being connected to the micro bubble generating device.

The mixed fluid generating means may be a pump having an impeller. In this case, the mixed fluid is preferably discharged to the upper side of the mixed fluid generating means.

The diameter ratio of the small diameter portion to the large diameter portion is preferably 1/10 to 1/9.

The length of the small diameter part of the reactor is preferably 0.2 to 2 cm.

The adjacent reactors may be connected in such a manner that the small diameter portion of the front end reactor is inserted into the large diameter portion of the rear end reactor. In this case, the adjacent outer ends of the front end reactor and the rear end reactor may be screwed.

In addition, the end of the reactor may further include a baffle provided perpendicular to the fluid flow.

The baffle may be provided with a blade extending horizontally in the fluid flow direction, and the blade is preferably provided on an opposite side to the small diameter portion of the reactor.

In addition, the reactor may further include a perforated plate provided on the large diameter portion of the reactor, and the perforated plate fluid inlet surface may be provided with a plate portion extending horizontally in the fluid flow direction. In this case, it is preferable that the number of holes is formed in each of the surfaces of the perforated plate partitioned by the plate-shaped portion.

In addition, the large-diameter portion of the reactor may further include one or more plate-like porous members.

The perforated plate and the at least one plate-like porous material are preferably provided sequentially in the fluid flow direction.

The reactor may further include a funnel-shaped porous member for supporting the plate-like porous member between the large-diameter portion and the small-diameter portion of the reactor.

The porous material may be any one selected from a wire mesh or a membrane, or a combination thereof.

In addition, it is preferable that a plurality of the porous materials are provided, and the hole size of the porous material disposed upstream in the flow direction of the fluid is larger than the hole size of the porous material disposed downstream.

The present invention also relates to a micro-bubble generator for generating micro-bubbles from a mixed gas of gas and liquid, wherein the micro-bubble generator has a plurality of tubular reactors tapered in the flow direction of the fluid from the large- To the micro bubble generator.

According to the apparatus for generating fine bubbles according to the present invention, fine bubbles can be generated continuously and stably, and bubbles generated by nanoizing the size of fine bubbles can be maintained in the liquid for a long time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a pump in a conventional micro-bubble generator. FIG.
2 is a schematic configuration view of a microbubble generator according to the present invention.
3 is a side sectional view and a front sectional view of a mixed fluid generating means of the micro-bubbling apparatus according to the present invention.
4 is a side cross-sectional view showing a connection state of the microbubble generator of the microbubble device.
5 is a detailed block diagram of a reactor according to the present invention.
6 is a side view of a baffle in accordance with the present invention;
7 is a front view and a side view of a perforated plate according to the present invention.
8 is a graph showing the pressure change of the mixed fluid according to the length of the small diameter portion of the reactor according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same or similar reference numerals are given to the same or equivalent elements in the drawings, and in the specification, when a component is referred to as being "including", it is to be understood that other components But may include other components.

3 is a side sectional view and a front sectional view of the mixed fluid generating means of the microbubbles apparatus according to the present invention, and FIG. 4 is a cross-sectional view of the microbubble generator of the microbubbles apparatus according to the present invention. And Fig.

The apparatus 10 for producing micro-bubbles according to the present invention includes mixed fluid generating means 200 for generating a mixed fluid of gas and liquid and fine bubble generating means 300 for generating fine bubbles.

In the disclosed embodiment, the mixed fluid generating means 200 is realized in the form of a pump having a known impeller 210, and includes a hose or tube type inlet pipe (220) and a discharge pipe (230) for transferring the mixed fluid to the micro-bubble generating means (300).

The liquid fluid and the gaseous fluid introduced through the inlet pipe 220 are vigorously mixed in the pump by the turbulent flow of the impeller 210 and mixed with a bubble of a predetermined size dispersed in the liquid through the outlet pipe 230 And is discharged into the micro-bubble generating means 300 in the form of a fluid.

On the other hand, when the bubbles existing in the mixed fluid have an excessive volume, the impeller 210, which is operated at high speed due to cavitation due to bubbles, may be damaged, or continuous and stable operation may be restricted due to overheating of the pump Furthermore, since the density of the bubbles is relatively low compared to the liquid fluid, in the conventional type of pump in which the discharge of the mixed fluid is made to the side or the lower side of the pump, the bubbles accumulate in the upper part of the inside of the pump.

3, one of the features of the apparatus 10 for generating microbubbles according to the present invention is that the mixed fluid generating means 200, that is, the liquid fluid and the gaseous fluid introduced into the pump are mixed by the impeller 210 And then discharged to the upper portion of the pump. In other words, when the mixed fluid is discharged to the upper portion of the pump, most of the bubbles dispersed in the mixed fluid are smoothly discharged through the discharge pipe 230 instead of accumulating in the pump, whereby continuous and stable operation of the mixed fluid generating means 200 Can be guaranteed.

Of course, even in the case of the mixed fluid generating means 200 according to the embodiment of the present invention, some bubbles may remain in the pump due to the pressure change in the mixed fluid due to the high rotation of the impeller 210, Since the density rises higher than the fluid of the liquid, the amount of bubbles present in the pump in the steady state can be kept constant so that continuous and stable operation of the pump is not hindered.

4, one of the other features of the apparatus 10 for generating microbubbles according to the present invention is that the microbubble generator 300 for generating microbubbles includes a plurality of tubular reactors 310 connected in series , So-called multi-impactor. Meanwhile, the micro-bubble generating means 300 according to the present invention may have a technical meaning associated with a solution to be solved in combination with the mixed fluid generating means 200 described above. However, the micro-bubble generating means 300 has a separate independent technical meaning Should be understood.

In the embodiment, the flow of fluid in the tubular reactor 310 is induced by the discharge pressure from the mixed fluid generating means 200, i.e., the pump, but the tubular reactor 310 is connected to the fine The bubble generating means 300 can also be driven by low pressure, such as water in a typical home.

The tubular reactor 310 has a tapered structure in which the cross-sectional diameter is reduced from the large-diameter portion 312 to the small-diameter portion 314 in the flow direction of the fluid, thereby basically utilizing the hydrodynamic cavitation phenomenon Resulting in fine bubbles.

In this case, the size of the generated minute bubbles can be calculated by the Bernoulli equation (Equation 1) and the Young-Laplace equation (equation 2) below.

In Equation 1, P: pressure; ρ: density of fluid; v: flow rate of fluid; g: gravitational acceleration; h is the height of the fluid, and P _G is the pressure of the gas; P _L is the pressure of the liquid; σ: surface tension of liquid; d _b ; And the diameter of the fine bubbles, respectively. Equation 1 shows that the sum of kinetic energy and kinetic energy of the fluid is always constant. According to Equation (1), as the speed of the fluid increases, the pressure inside the fluid decreases. On the contrary, when the speed decreases, the internal pressure increases. Therefore, in order to generate minute bubbles through the hydrodynamic means as in the present invention, Pressure changes must be induced. On the other hand, Equation 2 shows that the size of micro bubbles that can be generated in a gas-liquid mixed fluid can be generated by the pressure difference of the mixed fluid, and the larger the pressure difference between the front and back of the mixed fluid, It becomes smaller.

It is preferable that the diameter ratio (d / D) of the small diameter portion to the large diameter portion is 1/10 to 1/9 in consideration of the formation of fine bubbles, the size of the fine bubbles generated and the holding time. That is, the smaller the diameter ratio, the smaller the size of the fine bubbles to be produced. However, when the diameter difference is smaller than 1/10, that is, the larger the difference in diameter between the large diameter portion and the small diameter portion, There is a problem in the apparatus durability such as a risk of water leakage or an overload in the mixed fluid generating means 200, and the fabrication cost may be excessively increased or the smooth flow of the fluid may be hindered. If the diameter ratio is larger than 1/9 , That is, the smaller the difference in diameters between the large-diameter portion and the small-diameter portion becomes, it is difficult to expect the generation of fine bubbles.

The length (1) of the small-diameter portion is preferably a predetermined length. In the conventional venturi type micro bubble generator, the diameter is narrowed at a mid point of the pipe, and micro bubbles are generated through the similar effect to the orifice. In this case, however, the fluid suddenly pressures at a narrow diameter position There is a problem that the pressure is rapidly increased at the same time as it goes down and passes through the corresponding position, and the generated micro-grapes disappear at the same time. On the contrary, in the present invention, by keeping the pressure of the fluid constant by setting the length (1) of the small diameter part to be a predetermined length, it is possible to prevent the element which becomes a obstacle to the stable microbubble formation due to the change of the flow velocity or the change of the fluid pressure by the foreign substance Thereby minimizing the amount of the light.

FIG. 8 is a graph showing a change in pressure of the mixed fluid according to the length of the small diameter portion of the reactor according to the present invention. The change in pressure caused when the length of the small diameter part was changed under the condition that the flow rate and the flow rate of the mixed fluid in the small diameter part were constant was measured. 8, it is difficult to expect a constant pressure holding effect when the length (1) of the small diameter portion is smaller than 0.2 cm, and when the length is larger than 2 cm, the pressure difference effect required for microbubble formation is rather lost. From this point of view, the length 1 of the small diameter portion 314 is preferably 0.2 to 2 cm. However, in the length range of the allowable small diameter portion 314, the shorter the length, the smaller the size of the generated minute bubbles.

As shown in FIG. 4, the adjacent reactors 310 are connected in such a manner that the small-diameter portion of the front-end reactor is inserted into the large-diameter portion of the rear-end reactor on the basis of the fluid flow. The connection method is preferably a method in which the outer surface of the front end reactor and the rear end reactor are screwed together, but such a connection method is not limited and it is also possible to use welding or bonding.

A plate-shaped baffle 400 is provided on the end side of the small diameter portion 314 of the reactor 310 in a direction perpendicular to the fluid flow. The baffle 400 basically collides the minute bubbles in the mixed fluid discharged at a high speed through the small diameter portion 314 and breaks the bubbles into smaller sized bubbles.

The baffle 400 is formed by forming a step portion 313 in the large diameter portion 312 of the tubular reactor 310 and forming a baffle 400 May be fixed to the step portion 313 by a method. However, it is understood that the manner of fixing the baffle 400 is not limited.

4 and 6, a blade 410, which extends horizontally in the fluid flow direction, that is, perpendicular to the baffle 400, is provided in the baffle 400, And is opposed to the neck portion 314. The blade 410 functions to increase the decomposing effect of the microbubbles due to the collision, and also generates a collision sound when the microbubbles collide with each other, thereby audibly confirming whether the microbubbles are generated. Considering the role of the blade 410, the blade 410 is preferably sharp like a blade.

5 and 7, optionally, a perforated plate 700 is provided within the large diameter portion 312 of the reactor 310. The perforated plate 700 has an outer diameter substantially equal to the inner diameter of the large diameter portion 312. As described above, since the reactor 310 has a structure in which the inner diameter of the reactor is reduced from the large diameter portion 312 to the small diameter portion 314, the perforated plate 700 is formed in the large diameter portion 312 region And is fixedly positioned.

The perforated plate 700 has a plate portion 710 protruding horizontally in the fluid flow direction and is installed inside the reactor 310 such that the plate portion 710 faces the fluid inflow side. In this case, it is preferable that the perforated plate 700 is divided into two regions by the plate-shaped portion 710 and a different number of holes are formed on each of the divided surfaces.

The mixed fluid passing through the reactor 310 forms a temporary vortex by the plate portion 710 and thus a dead space exists in the vicinity of the plate portion 710 as a region which is not well mixed with the surrounding fluid do.

The dead space serves as a kind of buffer. That is, if the pressure of the fluid changes according to the physical change of the fluid, such as the flow rate of the fluid, the continuous and stable formation of the minute bubbles is hindered. This dead space reduces the pressure change of the fluid in the reactor 310, And the like.

On the other hand, bubbles having a large particle size generally remain in the dead space without being mixed with the surrounding mixed fluid. Since the vapor fluid remaining in the dead space is mainly present in the upper part of the tube of the reactor 310 due to its low density, it is smoothly discharged together with the fluid flowing out through the hole 720 formed in the perforated plate 700.

Referring to FIG. 5, the large-diameter portion 312 of the reactor 310 is selectively provided with one or more plate-like porous members 800. The plate-like porous member 800 is sequentially provided in the fluid flow direction, and is positioned behind the perforated plate 700 mentioned above. Since the porous material 800 has an outer diameter substantially equal to the inner diameter of the large diameter portion 312, by the structure of the reactor 310 in which the inner diameter is reduced from the large diameter portion 312 to the small diameter portion 314 Can be fixedly positioned in the large-diameter portion 312 region despite the fluid flow.

Such a porous material 800 is provided in the form of a wire mesh or a membrane having a number of holes as a kind of filter. In addition to the effect of micro-bubbling in the above-described Young-Laplace effect, the porous material 800 basically functions to divide coarse bubbles of relatively large size in the fluid into micro-particles due to collision effects. The effect of microbubbles generated by such collision can be increased as the number of porous materials 800 increases. Considering the role of the porous material 800, it is preferable that a porous material having a large pore size is located upstream in the fluid flow direction and a porous material having a small pore size is located in the downstream side. When the porous material having the smallest pore size is located upstream But also affects the durability of the porous material due to the hydraulic pressure.

5, a separate porous material 900 is additionally provided between the large diameter portion 312 and the small diameter portion 314 of the reactor 310 to support the porous material 800 . The porous material 900 is provided in the shape of a funnel so as to be accommodated inside the tapered transition portion 316 connecting the large-diameter portion 312 and the small-diameter portion 314. The funnel-like porous material 900 is positioned behind the aforementioned plate-like porous material 800 in the fluid flow direction.

The funnel-like porous member 900 is provided in the form of a wire net or membrane as in the case of the plate-like porous member 800, and basically serves to divide the coarse bubble into fine particles and supports the plate-like porous member 800, Thereby preventing the plate-like porous member 800 from being deformed.

The foregoing is a description of specific embodiments of the present invention. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments or constructions. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It should be understood that this is possible. It is therefore to be understood that all such modifications and alterations are intended to fall within the scope of the invention as disclosed in the following claims or their equivalents.

10: Micro-bubble generator 200: Mixed fluid generating means (pump)
210: impeller 220: inlet pipe
230: discharge pipe 300: fine bubble generating means
310: tubular reactor 312: large-
313: step portion 314: small neck portion
316: transition part D: large diameter part
d: small diameter 400: baffle
410: blade 500: support
600: Screw 700: Perforated plate
710: plate-shaped portion 720: perforated plate hole
800: Plate type multi-purpose material 900: Funnel type multi-material

Claims (17)

Mixed fluid generating means for generating a mixed fluid of gas and liquid; And fine bubble generating means for generating fine bubbles from the mixed fluid,
Wherein the fine bubble generating means is connected in series with a plurality of tubular reactors tapered from the large diameter portion to the small diameter portion in the flow direction of the cross sectional shape.
The fine bubble generator according to claim 1, wherein the mixed fluid generating means is a pump having an impeller.
3. The apparatus according to claim 1 or 2, wherein the mixed fluid is discharged to the upper side of the mixed fluid generating means.
The fine bubble generator according to claim 1, wherein the diameter ratio of the small diameter portion to the large diameter portion is 1/10 to 1/9.
The apparatus according to claim 1, wherein the length of the small diameter part of the reactor is 0.2 to 2 cm.
The apparatus according to claim 1, wherein the adjacent reactors are connected in such a manner that the small-diameter portion of the front-end reactor is inserted into the large-diameter portion of the rear-end reactor.
The apparatus of claim 1, wherein the adjacent reactors are threaded on the outer surface of the front end reactor and the inner surface of the rear end reactor.
The apparatus of claim 1, further comprising a baffle provided perpendicularly to the fluid flow provided on an end side of the reactor.
9. The apparatus according to claim 8, wherein the baffle is provided with a blade extending horizontally in a fluid flow direction on a side surface opposite to the small diameter portion of the reactor.
The apparatus of claim 1, further comprising a perforated plate provided in a large-diameter portion of the reactor.
11. The apparatus of claim 10, wherein the fluid inlet surface of the perforated plate is provided with a plate-shaped portion extending in the horizontal direction in the fluid flow direction, and the number of holes formed in each of the surfaces of the perforated plate defined by the plate- Of the micro bubble generator.
11. The apparatus according to any one of claims 1 to 10, further comprising one or more plate-shaped porous members provided on a large-diameter portion of the reactor.
The apparatus according to claim 12, wherein the large-diameter portion of the reactor is provided with a perforated plate and at least one plate-shaped porous member sequentially in the fluid flow direction.
13. The apparatus according to claim 12, further comprising a funnel-shaped porous member for supporting the plate-shaped porous member between the large-diameter portion and the small-diameter portion of the reactor.
13. The apparatus according to claim 12, wherein the porous material is any one selected from a wire mesh or a membrane or a combination thereof.
13. The micro-bubble generator according to claim 12, wherein the plurality of porous members are provided in such a manner that the hole size of the porous member disposed upstream in the flow direction of the fluid is larger than the hole size of the porous member disposed downstream. .
A micro-bubble generator for generating micro-bubbles from a mixed fluid of gas and liquid, wherein the micro-bubble generator is connected in series with a plurality of tubular reactors tapered in a flow direction of the fluid from a large- A micro bubble generator.

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