JPH0133211B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microbubble generating device for generating microbubble in various liquids.

[Prior art] As seen in sponge cakes, foam snowflakes, whipped cream, etc., the inclusion of many fine air bubbles in foods improves the texture, makes the taste milder, etc. It is known to improve sensory function. Conventionally, mechanical stirring and foaming devices such as a manual stirring and foaming device, a handle manual stirring and foaming device, and an electric stirring and foaming device have been used as bubble generating devices for this purpose.

However, in the above-mentioned conventional bubble generator, it is not only difficult to make the air bubbles uniformly fine even by adjusting the outer diameter, shape, and stirring speed of the whisk, but also the foaming efficiency is low. However, there was a problem in that the rate of bubble generation was slow.

The above-mentioned foaming problem is of interest not only in food products but also in various industrial fields, and a foaming device with good quality and high efficiency is desired.

[Purpose of the Invention] The purpose of the present invention is to solve the above-mentioned problems, and to improve the taste of foods and rapidly increase the amount of dissolved oxygen in liquids, it is possible to continuously and stably generate uniform microbubbles. An object of the present invention is to provide a device for generating microbubbles that can generate a large amount of microbubbles at high speed.

[Structure of the Invention] In order to achieve the above object, the micro bubble generator of the present invention includes a liquid nozzle 61 having an inner diameter d1 of 0.3 mm to 1.2 mm, and a jetting speed from the liquid nozzle 61.
A liquid supply section 83 capable of supplying liquid to the liquid nozzle 61 in order to eject the liquid 3 at V _L = 20 m/s to 50 m/s, and a gap |△L|=0.1 mm in front of the liquid nozzle 61. The liquid nozzle 6 is arranged so that the axes coincide with each other with a distance of ~6 mm, and the liquid nozzle 6
The gas ring thickness δg, which is the distance from the outer peripheral surface of 1, is
A gas nozzle 63 configured to have a diameter of 0.1 mm to 0.2 mm and arranged so that its tip faces the liquid to be foamed, and a gas supply section 65 capable of supplying an appropriate gas 67 to the gas nozzle 63. We are prepared.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3. FIG. 1 is a principle diagram of a micro bubble generator, FIG. 2 is a partial sectional view of an ejector-type gas nozzle, and FIG. 3 is an enlarged view of the nozzle portion of the ejector-type gas nozzle.

As shown in FIG. 1, the ejected liquid 3 such as water or oil stored in the ejected liquid tank 1 is passed through a flow rate adjustment valve 7, a heat exchanger 9, and a switching cock 29 by a liquid sending pump 5 to an ejector type gas nozzle. 11 or the preliminary ejector type gas nozzle 13 and is ejected into the liquid tank 41 or the preliminary liquid tank 31.

To explain in more detail below, 15 is an air chamber for smoothing unevenness in the liquid feeding pressure, 17 is a liquid feeding pressure gauge, 19 is a safety valve for returning excess liquid to the ejected liquid tank 1, and 21 is a feeding pressure gauge. It is a liquid flow meter. The heat exchanger 9, heating liquid tank 79, and heating heater 27 suitably heat the ejected liquid 3 in the heat exchanger 9, 23 is a heating oil tank thermometer, and 25 is a nozzle inlet pressure gauge. The switching pot 29 is used to send liquid to the preliminary ejector type gas nozzle 13 provided in the preliminary liquid tank 31 from the start of operation until a steady state is reached. 35 is an inlet thermometer of the ejector type gas nozzle 11 and the preliminary ejector type gas nozzle 13.
Reference numeral 65 indicates a gas suction pipe for the ejector type gas nozzle 11 and the preliminary ejector type gas nozzle 13, and in this example, the suction port thereof is opened to the air to suck air. 37 is an intake gas flow meter. A liquid to be foamed 43 is stored in the liquid tank 41 and the preliminary liquid tank 31, and a thermometer 39 is stored in the liquid tank 41.
and a heat exchanger 45 are provided. This heat exchanger 45 adjusts the viscosity of the foaming liquid 43 as appropriate by heating or cooling it.

Since the ejector-type gas nozzle 11 and the preliminary ejector-type gas nozzle 13 have exactly the same configuration, the ejector-type gas nozzle 11 will be explained as follows.As shown in FIG. It is screwed onto the nozzle body 51.
The liquid nozzle body 5 is inserted into the through hole 83 of the nozzle body 51.
9 is press-fitted, and the liquid nozzle 61 at the tip thereof is placed inside the parallel length L of the gas nozzle 63 formed in the gas nozzle body 55 by an overlap length ΔL, as shown in FIG. It is inserted and provided. On the other hand, in the upper part of the nozzle body 51,
A gas suction pipe 65 is provided and the gas suction pipe 6
A small hole 69 is drilled continuously to the gas suction pipe 6.
The gas 67 sucked in from the gas nozzle 63 is guided through the small hole 69 to the gas nozzle 63.
Further, by changing the thickness of the shim 70, the nozzle overlap length ΔL, that is, the relative position of the parallel portion of the gas nozzle 63 and the liquid nozzle 61 can be accurately determined.

Next, the operation of this embodiment will be explained.

When the ejected liquid 3 is pressure-fed from the ejected liquid tank 1 to the heat exchanger 9, it is heated by the heater 27 until it has a sufficiently low viscosity so that it can be ejected from the ejector type gas nozzle 11 at high speed. Subsequently, the ejected liquid 3 is force-fed to the pre-ejector type gas nozzle 13 via the switching cock 29, and is ejected from the pre-ejector type gas nozzle 13 into the pre-liquid tank 31.

When it is confirmed that the ejected liquid 3 is stably and continuously ejected from the preliminary ejector type gas nozzle 13 after a certain period of time has elapsed, the switching point 29 is switched,
The jetted liquid 3 is then forced to the ejector type gas nozzle 11. Ejector type gas nozzle 1
The ejected liquid 3 force-fed toward the nozzle body 51
From the liquid nozzle 61 through the through hole 83 of the liquid tank 4
It is squirted inside 1.

At this time, if the jetting speed of the jetted liquid 3 is sufficiently high, a low pressure area is generated around the jetted liquid 3, and this low pressure area is filled with air 67 through the gas nozzle 63, the small hole 69, and the gas suction pipe 65. is inhaled, and air 67 is ejected into the foamed liquid 43 along with the ejected liquid 3. The air 67 blown out in this way generates desired fine bubbles 81 in the foaming liquid 43.

Note that if the viscosity of the foaming liquid 43 is extremely low and there is a risk that the generated fine bubbles will float to the top of the liquid within a short time and diffuse into the air, the heat exchanger 4
5 to cool the foaming liquid 43 and increase its viscosity.

FIG. 4 shows an example of the bubble diameter distribution when fine bubbles are generated using the apparatus of the above embodiment. However, in this example, the ejected liquid 3 and the foamed liquid 4
3 were both used as salad oil. Also, the length of the parallel part of the gas nozzle is L = 1.5 mm, the inner diameter of the liquid nozzle is d ₂ = 0.36 mm,
The liquid nozzle outer diameter is d ₁ = 0.63 mm, the ejection gas ring thickness is δg = 0.15 mm, and the liquid pumping pressure is P = 7.0 Kgf/
cm ² , and microbubbles were generated in the foaming liquid 43 of No. 2 for 20 seconds. Then, by adjusting the thickness of the shim 70 and moving the gas nozzle body 55 back and forth with respect to the nozzle body 51, the nozzle overlap length ΔL is changed from -1.0 mm to -0.5 mm to 0.0 mm to 0.5 mm. This is what I did.

As can be seen from the figure, the nozzle overlap length △L
80 to 90% of the bubbles generated when -1.0 mm, -0.5 mm, 0.0 mm, and 0.5 mm have a bubble diameter of 50 to 50 mm.
It is 200μm. It is known that in the conventional mechanical stirring foamer, the diameter of the bubbles generated is approximately 200 to 800 μm, so the device of this embodiment produces much finer and more uniform microbubbles than the conventional device. can be generated.

FIG. 5 shows the average bubble diameter μm when the nozzle overlap length ΔL and the ejection ring thickness δg were varied from 0.10 mm to 0.15 mm to 0.20 mm. However, this average bubble diameter is given by = 2 ₃ √ 3 () 4 when the ejected gas flow rate is Qml/min and the bubble generation rate is N bubbles/min. This represents the average diameter of the bubbles, assuming that the bubbles are of a certain size. As can be seen from the figure, according to this embodiment, the average bubble diameter can be appropriately adjusted between 100 and 200 μm by selecting the ejection ring thickness δg and the nozzle overlap length ΔL.

In addition, the number of bubbles generated per minute, that is, the bubble generation rate, varies slightly depending on the ejection ring thickness δg and the nozzle overlap length ΔL, but it is approximately 3 to 6 ×
10 ⁶ (bubbles/min), making it possible to generate bubbles with high efficiency. Note that as ΔL decreases, the bubble generation rate increases, but if it is less than -0.5 mm, the bubble generation state may become unstable, which is not practical.

As described above, the micro-bubble generating device of this embodiment can generate a large amount of micro-bubble at a high speed, which is much finer and more uniform than the conventional device.

In the above embodiment, the suction port of the gas suction pipe 65 was opened to the air to suck air, but by connecting cylinders of various gases to the gas suction pipe 65, fine particles of gas other than air Bubbles can also be generated. Especially as this gas _N2
The use of inert gases such as or CO ₂ can be useful for preventing oxidative deterioration of foods and maintaining quality. Furthermore, by inhaling aromatic gases and incorporating these microbubbles into foods, it becomes possible to develop new foods.

Furthermore, in the above embodiment, both the liquid 3 jetted from the liquid nozzle 61 and the foamed liquid 43 that generates microbubbles are Newtonian fluids, but either or both may be a non-Newtonian fluid such as egg white or gelatin. is also possible. However, in that case, the nozzle diameters of the liquid nozzle 61 and the gas nozzle 63, the magnitude of the liquid pumping pressure, and the heater 2
7 and the presence or absence of the heat exchanger 45, etc. must be selected as appropriate. For example, for Newtonian fluid, it is appropriate that the nozzle diameter d ₁ of the liquid nozzle 61 is 0.6 mm to 1.0 mm, and the liquid pumping pressure P = 5 to 8 Kgf/cm ² , but for non-Newton fluid, d ₁ = 0.8 mm to 1.5 mm. At P=
6 to 12 kgf/cm ² is suitable. In this way, the desired amount of fine bubbles can be contained even in non-Newtonian fluids such as egg white and gelatin.

Further, in the embodiment described above, the ejector type gas nozzle 11 was provided below the side surface of the oil tank 41, but it may also be provided above the side surface. In this way, the ejected liquid 3
The liquid pumping force P can be made considerably smaller than the liquid pumping force P of the above embodiment. However, in this case, in order to prevent the generated microbubbles 81 from rising to the surface of the liquid within a short time and spreading into the air, a stirrer for the foamed liquid 43 is provided in the oil tank 41, and the microbubbles are appropriately stirred. It is desirable to do so.

Furthermore, by installing an automatic control device linked to a computer, it is possible to control the bubble generation state with a single touch. For example, the thermometer mentioned above,
The temperature, pressure, flow rate, etc. are detected using a pressure gauge, flow meter, etc., and the opening degree of the flow rate adjustment valve 7 and the inflow amount of the suction gas 67 are controlled via the control computer, and the bubble generation speed is automatically adjusted. Foaming liquid 4
It is possible to control the bubble density (in other words, the bubble content) to an appropriate value.

Of course, by increasing the number of ejector type gas nozzles 11, the amount of foaming per unit time can be increased.

Furthermore, the foaming liquid 43 does not necessarily have to be stationary as in the above embodiments, but may move slowly in a pipe, for example.

The present invention can be used not only as a means for incorporating microbubbles into foods as described above, but also as a foaming means in other fields as described below.

(1) For example, in the livestock industry, there is a long-awaited technology to improve the digestion and absorption of feed in order to promote the growth of young livestock. Knowledge has been obtained that it is effective. Therefore, the growth of young livestock can be promoted by generating microbubbles in the drinking water of livestock using the microbubble generator.

(2) Furthermore, aquaculture and cultivated fish industries are becoming more popular due to the depletion of fish resources, but when cultivating large quantities of fish in a large-scale aquaculture system, it is necessary to ensure the amount of dissolved oxygen in the seawater. be. The micro bubble generator of the present invention is also optimal for supplying dissolved oxygen. In other words, the smaller the diameter of the air bubbles blown into seawater, the larger the surface area, and the more easily they dissolve in the water.
Because it can generate ultrafine oxygen bubbles at high speed, large amounts of oxygen can be dissolved into seawater extremely easily.

(3) Furthermore, foaming agents are used to produce abrasion-resistant concrete containing air bubbles; however, foaming agents not only do not produce uniform cell diameters, but also have large bubbles, which naturally limits their uses.

Therefore, by incorporating ultrafine bubbles into fresh concrete using the microbubble generating device of the present invention, it becomes possible to provide a variety of concrete materials such as lightweight concrete and heat-insulating concrete at low cost.

[Effects of the Invention] As stated in the first claim, the present invention uses an ejector-type gas nozzle to eject a liquid into a liquid to be foamed, and also injects gas into a low pressure area generated by the ejected liquid. This is a micro-bubble generator that sucks in the gas, ejects the gas into the liquid to be foamed together with the ejected liquid, and generates micro-bubbles that enclose the gas, so compared to conventional stirring-type whisks, the foaming rate is higher. Since the bubble diameter is extremely fine and the bubble generation rate is high, the foaming operation can be carried out highly efficiently and continuously. In particular, by setting the nozzle diameter of the liquid nozzle, the gas nozzle, the fluid ejection speed, etc. as described in the claims, the bubble diameter is 10 μm or more.
200 μm bubbles can account for 80% to 90% of all generated bubbles.

In addition, since the present invention can suck various gases other than air, it can be used, for example, to generate microbubbles to prevent food deterioration, to develop new foods containing aromatic bubbles, or to inject into water. It can be used in a wide variety of industrial fields, such as for rapidly dissolving large amounts of oxygen.

[Brief explanation of drawings]

Figures 1 to 3 all show embodiments of the present invention, and Figure 1 is a diagram of the principle of a microbubble generator;
FIG. 2 is a detailed sectional view of the ejector type gas nozzle, and FIG. 3 is an enlarged view of the nozzle portion of the ejector type gas nozzle. FIG. 4, FIG. 5, and FIG. 6 respectively show the bubble diameter distribution, average bubble diameter, and bubble generation rate of microbubbles according to the above embodiment. 3... Ejected liquid, 11... Ejector type gas nozzle, 27... Heater, 43... Liquid to be foamed,
57...screw, 61...liquid nozzle, 63...gas nozzle, 65...gas suction pipe, 67...gas,
70...Sim.

Claims (1)

[Claims] 1. A micro-bubble generator for generating micro-bubbles 81 in a liquid to be foamed 43, comprising: a liquid nozzle 61 having an inner diameter d1 of 0.3 mm to 1.2 mm;
And, the jetting speed V _L = 20 m/ from this liquid nozzle 61
A liquid supply unit 83 capable of supplying liquid to the liquid nozzle 61 to eject the liquid 3 at a speed of s to 50 m/s, and a distance |△L|= in front of the liquid nozzle 61.
The gas rings are arranged so that their axes coincide with each other at a distance of 0.0 mm to 6 mm, and the gas ring thickness δg, which is the distance from the outer peripheral surface of the liquid nozzle 61, is 0.1 mm to 0.2 mm. The liquid 3 supplied from the liquid supply section 61 is provided with a gas nozzle 63 disposed so as to face the liquid to be foamed, and a gas supply section 65 capable of supplying an appropriate gas 67 to the gas nozzle 63. By ejecting the gas 67 as a liquid stream from the liquid nozzle 61 and sucking the gas 67 into a low-pressure area generated around the liquid stream, the gas 67 and the liquid 3 are ejected together from the gas nozzle 63 to form the foamed object. A microbubble generator that generates microbubbles in liquid 43. 2. The micro bubble generator according to claim 1, wherein the gas nozzle 63 has a parallel portion with a length L of 3 mm to 15 mm. 3 The liquid nozzle 61 and the gas nozzle 63
3. The microbubble generating device according to claim 2, wherein each of the microbubble generators has a cylindrical hole. 4 The gas nozzle 53 is the liquid nozzle 61
3. The microbubble generating device according to claim 2, wherein the microbubble generating device is provided so as to be movable in the direction in which the liquid 3 is ejected. 5 The gas nozzle 61 is the liquid nozzle 63
5. The microbubble generating device according to claim 4, wherein the device is movable in the direction in which the liquid 3 is ejected. 6 Depending on whether the liquid 3 ejected from the liquid nozzle 61 is a Newtonian fluid with a low clay content, such as water or oil, or a non-Newtonian fluid with a high clay content, such as egg white or gelatin, the nozzle system, the magnitude of the liquid delivery pressure, and the heating heater 27 and The fine bubble generating device according to claim 1, characterized in that the presence or absence of a heat exchanger 45 is determined.