JPS5941780B2 - Complex fluid jet method and complex nozzle unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for mixing and atomizing two or more types of fluids including gases, liquids, and powders and dispersing them into jets. The present invention relates to a method for producing a dispersed jet after dispersion, and a composite nozzle unit that skillfully implements this method.

Conventionally, methods for atomizing and dispersing fluids, especially liquids, include methods using nozzles, methods using rotation mechanisms that utilize centrifugal force, and methods using ultrasound generators that generate ultrasound electrically or mechanically. Although it is used,
The most common method for obtaining a large amount of fluid particles by simple mechanical means is to use a nozzle.

Methods using nozzles include high-pressure spraying, in which liquid is sprayed into gas under high pressure, and liquid and gas are sprayed at high pressure through separate nozzle pores, and they collide with each other to form a mixed spray of gas and liquid. Methods such as obtaining the body are used. However, in order to promote atomization of the liquid well, the liquid or both the liquid and the gas must be pressurized to a high pressure of several atmospheres to several tens of atmospheres, and the fluid must be ejected from a nozzle pore with a small diameter. Since spraying is required, there are unresolved problems such as clogging of the nozzle pores and deterioration of the ejection function, and unavoidable functional deterioration due to abrasion of the pores.
Furthermore, when using conventional nozzles, it is extremely difficult to supply two or more types of liquids to one nozzle to achieve emulsion-like mixing and atomization of the liquids. In view of the state of the conventional fluid mixing atomization technology, the main purpose of the present invention is to mix two or more types of fluids to form fine particles in multiple stages, regardless of the properties of gas, liquid, and powder. It is an object of the present invention to provide a method and device means that can obtain a completely atomized mixed fluid by atomizing the mixed fluid, and can also disperse and jet the mixed fluid to the outside. Another object of the present invention is to connect and connect nozzle elements having large nozzle holes in a stepwise manner.
It is an object of the present invention to provide a fluid composite nozzle unit that can promote mixing and atomization of more than one type of fluid and can disperse and jet the mixed fluid at an arbitrary opening angle.

Still another object of the present invention is to provide a fluid composite nozzle unit which can be manufactured relatively easily by mechanical cutting and assembly, and which can efficiently mix and atomize fluid and eject it as a dispersed jet. It is to provide.

That is, according to the present invention, the first fluid flowing along the flow path is accelerated to a higher speed in the first contraction area, and then passed through the divergent jet area, thereby increasing the flow rate in the flow passage cross-sectional reduction area of both of the areas. generating a low-pressure part in the low-pressure part, and at this time, guiding at least one type of second fluid into the low-pressure part, and mixing and crushing both fluids with each other in the divergence region to atomize them;
Next, the mixed fluid is guided to a second contraction area and ejected at high speed, and then collided with a fluid reflection plate provided outside the front of the second contraction area to create a reflected flow of the mixed fluid within this collision reflection area. The mixed fluid is then atomized in multiple stages by colliding the reflected flow with the mixed fluid subsequently ejected at high speed from the second contraction region in the collision reflection region, and the mixed fluid is atomized in multiple stages and directed toward the external space. Thus, there is provided a composite fluid jet method characterized in that the fluid jet is dispersed in an open umbrella shape.

Further, according to the present invention, two or more types of fluid composite nozzles (gas, liquid, and powder) are mixed and atomized using a first nozzle that mixes and atomizes them in an arbitrary ratio in advance, and a The second mixed fluid ejection nozzle is connected and the mixed fluid is ejected from the ejection hole of the second nozzle to further promote mixed atomization. By providing a substantially cylindrical fluid reflecting element having a circular reflecting hole with a concave cross-section, the mixed fluid flows into the reflecting hole of this reflecting element, is reflected, and collides with the subsequent mixed fluid. Very fine mixed particles can be obtained as a dispersed jet.

In this way, by combining two nozzles and promoting mixing and atomization in each nozzle, and in addition, by utilizing fluid collision, it is possible to generate a jet that is significantly larger than the jet hole of a conventional nozzle, from several tens to a hundred times larger. Even if holes are used, mixing and atomization of the fluid can be carried out very effectively, and since the ejection holes are large, problems caused by deterioration of ejection function due to clogging can be eliminated.

Furthermore, by configuring the distance between the ejection hole of the second mixed fluid ejection nozzle and the fluid reflection element to be variable, the direction of collision and dispersion between the ejected flow of the mixed fluid and the reflected flow can be changed, and the dispersion angle can be adjusted appropriately in an open umbrella shape. Can be set to .

In addition, the direction of the dispersed jet can be forcibly changed by attaching an annular dispersion angle adjuster disposed coaxially around the second mixed fluid ejecting nozzle so as to be movable in the nozzle axis direction and setting it appropriately. In some cases, the dispersion angle can be appropriately set in an open umbrella shape. As described above, the composite nozzle unit according to the present invention has an excellent fluid mixing atomization function and a dispersion jet function, and can be effectively applied to the following various uses.

(1) The fluid composite nozzle unit according to the present invention is installed so that its jet port is directed into the gas, and
If the composite nozzle unit mixes and atomizes multiple types of liquid into the upper air and causes the mixture to be dispersed and jetted, it can be used, for example, as an atomization nozzle for liquid fuel.

Moreover, it can also be used as a nozzle that mixes two or more types of fuel and water or a chemical liquid additive, atomizes the mixture, and sprays the mixture in a dispersed manner. By utilizing these applications, it is possible to realize low-pollution combustion devices, gas turbines, engines, etc. that perform highly efficient combustion. Furthermore, the composite nozzle unit according to the present invention can atomize high-viscosity, low-quality fuel, waste oil, etc. without clogging, making it possible to realize a combustion apparatus for such low-quality fuel and waste oil. Further, it is possible to realize an apparatus in which various waste liquids are mixed with fuel liquid and atomized and then subjected to combustion treatment, or only waste liquid is atomized and sprayed into a combustion chamber. Furthermore, by atomizing the liquid, it can be rapidly evaporated and dried, so we can realize a device that can produce uniform fine powder from a solution, and we also aim to realize a water atomization spray device for humidification and cooling. I can do it. On the other hand, by atomizing the liquid into gas and dispersing it by spraying, sufficient contact between gas and liquid can be achieved.For example, when water from a fish pond is sprayed into the air, it comes into contact with oxygen components. It can also be applied as a means of removing chlorine gas from tap water by dissolving oxygen in the water by dissolving the oxygen in the water by returning it to the irrigation pond, or by spraying the tap water into the gas. (2) The fluid composite nozzle unit according to the present invention is installed so that its jet port is directed into the liquid, and at least one type of gas is mixed and dispersed into the liquid from the composite nozzle unit into fine bubbles. If configured as follows, it can be used, for example, as a nozzle for microbubbling and dispersing air or oxygen in a liquid. Therefore, by utilizing such applications, high-efficiency gas-liquid contact equipment can be realized, and it can be installed in gas-liquid contact oxidation towers in flue gas desulfurization and denitrification processes, and can be used for dissolving oxygen and other gases in liquids in fermentation tanks. It can be applied to means, waste liquid, aeration means in wastewater treatment processes, other gas absorption means, and deaeration means. Furthermore, the present invention has realized a flotation separation device that floats and separates suspended matter, oil droplets, etc. in a liquid by using microbubbles generated from a fluid composite nozzle unit, and also a device that replaces gas in a liquid. By realizing this, it is possible to realize a device that replaces corrosive gas with nitrogen gas in the seawater desalination process. (3)
A device for mixing two or more liquids by installing a fluid composite nozzle unit according to the present invention in a liquid, circulating this fluid through the composite nozzle unit, mixing it with another liquid, making it atomized, and dispersing and ejecting it into the liquid again. can be realized.

(4) The mixed fluid jetting port of the fluid composite nozzle unit according to the present invention is installed to face the gas, and the composite nozzle unit is configured to spray out at least one kind of powder in a dispersed manner. It is possible to achieve atomization of particles, homogenization of powder particles, or mixing of two or more types of powder.

For example, it is possible to realize a device that transforms non-uniform powder into a uniform fine powder by emitting a jet stream together with gas from a composite nozzle unit, or a device that mixes two or more types of powder by jetting. By following the composite fluid jet method according to the present invention and also by utilizing the fluid composite nozzle unit according to the present invention, it is possible to adapt to various applications as described above. A composite nozzle unit according to the invention will now be described in detail with reference to one embodiment shown in the accompanying drawings.

FIG. 1 is a longitudinal cross-sectional view of an embodiment of a fluid composite nozzle unit 10 according to the present invention. In this FIG. 1, reference numeral 11 denotes a first nozzle for premixing, which has a threaded pipe part 12 connected to a fluid inflow pipe (not shown), and has a fluid inflow hole 1.
A conical constriction part 1 that accelerates the fluid F1 flowing in from 3.
4 and a diverging conical opening 15 for ejecting water are arranged concentrically. A fluid supply hole 1 with a diameter D2 is located at a position closer to the opening 15 from the minimum throttle part 16 with a flow path cross-sectional diameter d1.
(In FIG. 1, only two fluid supply holes 17 facing each other in the cross section of the composite nozzle are shown.)
). These fluid supply holes 17 are preferably formed perpendicularly to the central axes of the constricted portion 14 and the opening 15 as shown, and the supply pipes 17a are press-fitted and fixed therein. A guide pipe 18 is connected to the opening 15 of the first nozzle 11 for premixing to guide the atomized mixed fluid ejected therefrom, and in this embodiment, it is a straight pipe with a circular hollow flow path. It is formed as a section. A second nozzle 2 for ejecting mixed fluid is provided at the tip of the guide tube 18 with a conical constriction part 19 and a circular mixed fluid ejecting hole 20 having a diameter D3 of the flow path cross section.
1 is formed. The guide tube 18 and the first nozzle 11 are connected to each other by a female and male thread 12. Further, in this embodiment, the second nozzle 21 is formed at the tip of the guide tube 18 by integral processing, but it is of course possible to form the second nozzle 21 so as to be connected to each other by a female and male screw, if desired. The mixed fluid ejection hole 20 of the second nozzle 21 is disposed coaxially with the opening 15 of the first nozzle, and has an inner diameter D4 coaxially on the front outside of the ejection hole 20 and has a concave cross section as shown in the figure. A substantially cylindrical mixed fluid reflector 24 having a circular reflecting hole 23 is provided. This mixed fluid reflector 2
In the case of this embodiment, 4 extends along the central axis of the guide tube 18, and as shown in FIG. It is held by a support shaft 28 which is held and fixed by supports 26 and 27 having support legs 25. Moreover, the mixed fluid reflector 24 is fixed on the support shaft 28 by a screw 29, and after loosening the screw 29 and adjusting the distance 11 from the mixed fluid jetting hole 20 as appropriate, the mixed fluid reflector 24 is fixed on the support shaft 28 again.
It can be attached to the top. If this distance 1 is set to the optimum distance as described later, the mixed fluid reflector 24
Press fit a ring member (not shown) into the outer peripheral surface of the screw 29.
It is preferable to prevent it from coming off and to fix it completely. Furthermore, it goes without saying that the fluid reflector 24 and the support shaft 28 can be fixed even more securely by forming in advance a suitable notch or groove in the support shaft 28 into which the leading end of the screw 29 engages.
In a composite nozzle unit with such a configuration,
Since the pressure of the opening 15 from which the fluid F1 is ejected at high speed is hydrodynamically reduced, the fluids F2 and F3 to be mixed and atomized are supplied to this part through the fluid supply holes through the respective flow control valves 30 and 31. An arbitrary amount is extracted from the fluid F1, mixed with the fluid F1, crushed, and atomized. The position of the fluid supply hole 17 is from the minimum throttle part 16 to the fluid supply hole 17.
By selecting the distance 12 to the center from 1.5d2 to 3d2, the low pressure effect and the mixing atomization effect can be used most effectively. That is, when the fluid supply hole 17 is brought closer to the minimum aperture part 16 than 1.5d2, the fluid F1
The low pressure effect and the mixing atomization effect decrease at a distance from 3d2. In addition, the first nozzle 11
The taper inclination angle is formed to be around 10 degrees at the conical throttle part 14, and around 7.5 degrees at the diverging conical opening 15, and the effective flow path of the mixed fluid jet hole 20 of the second nozzle 21 is By selecting the cross-sectional area (the value obtained by subtracting the cross-sectional area of the support shaft 28 from the total cross-sectional area of the jet hole 20) from 1.0 times to 3.0 times the flow path cross-sectional area of the smallest part 16 of the constriction part 14. This makes it possible to make the hydrodynamic low pressure effect and the fluid mixing atomization effect as effective as possible. That is, 1.0
If the pressure is selected to be 3.0 times or less, the pressure inside the second nozzle 21 will become high, and if the pressure is selected to be 3.0 times or more, the pressure inside the second nozzle 21 will increase.
This results in a decrease in the jetting speed of the fluid, which results in a decrease in the mixing and atomization function of the fluid. Fluids Fl, F2, and F are mutually mixed and atomized in the first nozzle 11 for premixing.
The mixed fluid consisting of 3 passes through the guide pipe 18 and is accelerated again at a high speed by the conical constriction part 19 formed with a taper inclination angle of around 7.5 degrees. The liquid is ejected at a speed close to the speed of sound), and is caused to rush into and collide with the inside of the reflection hole 23 of the fluid reflector 24. Then, the mixed fluid that has collided with the inside of the reflection hole 23 is jetted out from inside the reflection hole 23 as a reflected flow, and collides with the atomized mixed fluid that is jetted out subsequently from the jetting hole 20 of the second nozzle 21. In this reflection collision area, a second stage of mixing and atomization is performed again, and then the particles are dispersed in an open umbrella shape. With reference to FIG. 1, the circular reflection hole 23 of the fluid reflector 24
The depth 13 of the nozzle is selected to be 1/2 to 1/3 of the inner diameter D4, and the inner diameter D4 is 0.8 to 1.2 times the diameter D3 of the mixed fluid jetting hole 20 of the second nozzle 21. Also, the maximum outer diameter D5 of the fluid reflector 24 is set to the jet hole 2.
By selecting and forming the diameter 1.6 times or less of the diameter D3 of 0, the effect of reflecting the mixed fluid from the fluid reflector 24 and dispersing it with the subsequent mixed fluid by mutual collision is enhanced, and further atomization of the mixed fluid is achieved. It can be promoted. Further, as described above, the opening-shaped dispersion angle α of the mixed fluid is adjusted by the second nozzle 2.
This can be done by changing the distance 11 between the mixed fluid jetting hole 20 and the fluid reflector 24 to increase or decrease the reflected collision area. That is, by decreasing 11, the dispersion angle α increases, and by increasing e1, the dispersion angle α decreases.

Furthermore, the dispersion angle α should be made extremely small, or α should be set to 1.
When opening to a dispersion angle of 80 minutes or more, reduce 21 to make the dispersion angle α as large as possible, and in addition, the second nozzle 2
The dispersion angle adjuster 32 coaxially fitted to the tip of the dispersion angle adjuster 32 is moved backward in the axial direction. Here, by pulling the dispersion angle adjuster 32 forward toward the fluid reflector 24, the dispersed flow of the mixed fluid can be forcibly deflected forward to reduce the dispersion angle α. As shown in Fig. 3, a low pressure region Z is hydrodynamically created behind the dispersed flow of the mixed fluid by moving the dispersed flow backward, and the dispersed flow is sucked backward as shown by the streamline S1. It can be dispersed in an open umbrella shape. Dispersion angle adjuster 32
can be secured onto the outer periphery of the second nozzle 21 using screws 33. Furthermore, in the fluid reflector 24, if a flange-shaped protrusion 24 made of a partially conical surface is formed on the outer periphery of the edge of the fluid reflection hole 23, the fluid will flow in front of the dispersed flow of the mixed fluid, as shown by the streamline S2 in FIG. Under the influence of the dynamically generated low pressure region Z2, a reverse entrainment flow of the mixed fluid can be significantly generated. Such a reverse entrainment flow is effective for stabilizing combustion and for rapid combustion by entraining and supplying air into the flame, for example, when a combustion device is constructed in which fuel liquid is atomized and combusted from the composite nozzle unit according to the present invention. , is extremely effective in preventing localized temperature rise. Further, when the composite nozzle unit according to the present invention blows out microbubbles to achieve airtight contact, it is also effective in promoting gas-liquid mixing and gas dissolution. Next, a typical example in which the effects of the composite nozzle unit 10 according to the present invention were demonstrated will be described.

Example 1 A composite nozzle according to the present invention was used as a fuel spray nozzle for a fire and smoke tube boiler with an evaporation rate of 0.3 tons per hour.
01/Hr? ×100 ratio A heavy oil + water to 0.8 kg/G at 20%, 25% and 30% water
When mixed and atomized combustion was carried out by air spraying at a pressure of 1.5%, the concentration of nitrogen oxides (Ppm) in the exhaust gas could be reduced to 80, 55, and 40, respectively, at 3% oxygen.

With the high-pressure spray nozzle conventionally used as a fuel spray nozzle, the nitrogen oxide concentration in the exhaust gas from the combustion of A heavy oil 301/Hr is 80 to 120 (PPrI) at 3% oxygen.
1), and it is understood that the use of the composite nozzle unit of the present invention has a remarkable low-pollution combustion effect. FIG. 5 is a system diagram schematically showing the present composite nozzle unit 10 and piping state during implementation. Example 2 The composite nozzle unit 10 according to the present invention was used as a fuel spray nozzle for a two-body water tube natural circulation boiler with an evaporation rate of 3 tons per hour, and A heavy oil 2601/Hr was atomized with steam at a pressure of 2.8 kg/~G. The A heavy oil is sprayed as secondary air for combustion in a direction approximately in front of the ejection hole 20 of the present composite nozzle unit 10 so as to be parallel to the open conical surface in the atomized wide-angle dispersion pattern of A heavy oil from the present composite nozzle unit 10. 200mT
When the fuel oil was supplied uniformly around the IL in a thin film form from the slit at a high speed of 60 m/Sec, premixing of A heavy oil and air and combustion with effective flame cooling, the exhaust gas The concentration of nitrogen oxides in the inside is 40 (at 4% oxygen).
Ppm).

Conventionally, the high-pressure spray nozzle used as a fuel injection nozzle had a fuel injection rate of 80 (Ppm), and it was understood that the atomization characteristics and wide-angle dispersion of the fuel liquid by the composite nozzle unit of the present invention are effective for low-pollution combustion. . Example 3 A composite nozzle unit 10 according to the present invention has an inner diameter of 500 m7.
7! φ, installed vertically at the bottom of a cylindrical container with a height of 2000 mm, and air 150 N1/min from this composite nozzle unit for 350 liters of sodium sulfite solution in the container.
and the above-mentioned sodium sulfite solution taken out by pump circulation from the above-mentioned container were mixed and ejected, and the air was microbubbled and dispersed to perform gas-liquid catalytic oxidation. The oxidation rate was approximately twice that of the oxidation rate using the gas apparatus.

This means that the diameter of the bubbles generated from the composite nozzle unit 10 according to the present invention is small, allowing for a large gas-liquid contact area, and that wide-angle dispersion of microbubbles is effective for gas-liquid contact. Example 4 A composite nozzle unit according to the present invention was installed vertically at the bottom of a container with an inner diameter of 300 mm and a height of 2000 mm, and was used to inject 1.5% oil in an alkaline degreasing liquid used in machine production processes and automobile production processes. A 1N. e/seedlings 1n and the emulsion waste liquid 151/den 1n taken out from the container by pump circulation
The oil content was reduced to 0.1% or less, and the degreasing waste liquid could be reused by mixing and ejecting the oil, making the air finely dispersed, adhering to the oil droplets, and causing them to float and separate.

Oil removal from degreasing waste liquid is usually done using a centrifugal separator.
Since it is necessary to apply an acceleration of 10,000 to 10,000 G, the device is expensive, and the processing capacity is extremely small compared to the present composite nozzle unit. Therefore, the effectiveness of the composite nozzle unit 10 according to the present invention for flotation separation has been recognized. FIG. 6 is a system diagram schematically showing the installation state of the composite nozzle unit 10 in practice. The structure, operation and effects of the representative embodiment of the fluid composite nozzle unit according to the present invention, and application examples of the composite nozzle unit have been described above, but various modifications can be made to the structure of the composite nozzle unit of the present invention. For example, instead of the structure in which the first nozzle and the second nozzle are directly connected integrally through the fluid guide pipe as in the above embodiment, it is also possible to connect the first nozzle and the second nozzle through a piping line. be.

Furthermore, in various applications using the composite nozzle unit according to the present invention, not only a single composite nozzle unit can be used, but also a large number of composite nozzle units can be arranged in parallel to increase the mixing capacity of fine particles as necessary. Alternatively, it is also possible to arrange a large number of composite nozzle units in series in a deep fluid bath to exhibit the mixing atomization function and the dispersion jet function over multiple stages.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of a fluid composite nozzle unit according to the present invention, FIG. 2 is a sectional view taken along the - line in FIG. 1, and FIGS. A cross-sectional view of the tip of the unit showing streamlines of a dispersed flow of a mixed fluid; FIG. 5 is a schematic diagram of a piping system in an embodiment in which the composite nozzle unit according to the present invention is used as a nozzle in a liquid fuel combustion device; FIG. 6 is a schematic diagram of a piping system in an embodiment in which the composite nozzle unit according to the present invention is used as a nozzle for atomizing and dispersing air in a degreasing apparatus. In the figure, 10 is a fluid composite nozzle unit, 11 is a first nozzle for premixing, 13 is an inflow hole, 14 is a conical constriction part, 1
5 is a diverging conical opening, 16 is a minimum constriction part, 17 is a fluid supply hole, 18 is a guide pipe for mixed fluid, 19 is a constriction part of a second nozzle, 20 is a mixed fluid ejection hole, and 21 is a second nozzle. ,
23 is a reflection hole, 24 is a fluid reflector, and 32 is a dispersion angle adjuster.

Claims (1)

[Scope of Claims] 1. The first fluid flowing straight along the flow path is accelerated to a higher speed in the first contracted region, and then passed through the divergent jet region, thereby reducing the flow channel cross-sectional area in both of the regions. a low-pressure area is created in the interior, and at this time, at least one
A second type of fluid is induced to flow in, the two fluids are mutually mixed and crushed in the divergence region, and atomized, and then the mixed fluid is guided to a second contraction region provided downstream and ejected from there at high speed. This is then caused to collide with a fluid reflector provided outside the flow path on the downstream side of the second contraction area to generate a reflected flow of the mixed fluid within this collision reflection area, and then a subsequent flow from the second contraction area. The mixed fluid is atomized in multiple stages by colliding the reflected flow with the mixed fluid ejected at high speed in the collision/reflection area, and the mixed fluid is dispersed in an open umbrella shape toward the outside space. Composite jet method for fluids. 2. It has a conical constriction part that accelerates the fluid introduced from the inlet opening of the cylindrical body, and a diverging conical opening part that is connected to the constriction part and ejects the fluid, and another fluid is ejected from around the opening part. a cylindrical first nozzle provided with at least one fluid supply hole in a cylindrical body wall to allow fluids to flow therein for first-stage mixing and atomization; and the opening of the cylindrical first nozzle. A guide connecting pipe that guides the mixed fluid jetted from the pipe downward in a substantially straight line and promotes mixing; a conical constriction portion connected to the downstream outlet of the guide connecting pipe; and a circular constriction portion formed at the tip of the conical constriction portion. a substantially cylindrical fluid reflecting element provided with a mixed fluid ejecting hole and a circular reflecting hole with a concave cross section disposed coaxially in front of the mixed fluid ejecting hole and facing the mixed fluid ejecting hole; A fluid ejection hole and a cylindrical second nozzle that performs a second stage of mixing and atomization in a collision reflection area formed between the fluid reflection element are sequentially connected, and two or more types of fluids are mixed and atomized. A composite nozzle unit for fluid that produces a dispersed jet stream. 3. In the fluid composite nozzle unit according to claim 2, the substantially cylindrical reflective fluid element of the second cylindrical nozzle receives the reflective fluid from the end face facing the mixed fluid ejection hole of the second cylindrical nozzle. 1. A fluid composite nozzle unit comprising a flange-like protruding end having a partially conical surface converging toward the outer peripheral surface of a fluid element. 4. In the fluid composite nozzle unit set forth in claim 2, the guide connection pipe connects the cylindrical first nozzle and the cylindrical second nozzle along a coaxial line, and forms a circular hollow fluid path. 1. A fluid composite nozzle unit comprising a straight pipe member having: 5. In the fluid composite nozzle unit according to claim 2, the fluid supply hole formed in the cylindrical wall of the cylindrical first nozzle is perpendicular to the central axis of the diverging conical opening. A composite nozzle unit characterized by being provided in. 6. In the fluid composite nozzle unit according to claim 2, the cylindrical second nozzle is further attached around the conical constriction part and can be adjusted back and forth along the axial direction of the conical constriction part. A hollow annular dispersion angle adjuster provided in the cylindrical second nozzle is provided, and the dispersion jet is A fluid composite nozzle unit characterized in that the dispersion angle of the fluid can be adjusted in an open umbrella shape. 7. In the fluid composite nozzle unit according to claim 2, 3, or 4, the cylindrical fluid reflecting element of the second cylindrical nozzle is aligned with the central axis of the second cylindrical nozzle. The cylindrical second nozzle is attached to the outer tip of a support shaft extending along the support shaft, and is provided so as to be movable back and forth with respect to the mixed fluid ejection hole of the cylindrical second nozzle on the support shaft. A fluid composition characterized in that the dispersion angle of the dispersion jet can be adjusted in an open-shape manner by selectively adjusting the distance between the mixed fluid jetting hole of the second nozzle and the fluid reflecting element. nozzle unit. 8. In the fluid composite nozzle unit according to claim 2, the opening area of the mixed fluid ejection hole of the cylindrical second nozzle is 1 of the minimum opening area of the conical constriction part of the cylindrical first nozzle. A composite nozzle unit for fluid, characterized in that the nozzle unit is selected from .0 times to 3.0 times. 9. In the fluid composite nozzle unit according to claim 2 or 5, the fluid supply hole formed in the cylindrical wall of the cylindrical first nozzle has a conical shape of the cylindrical first nozzle. At a dimensional position selected such that the distance from the minimum diameter part of the constriction part to the center of the fluid supply hole toward the diverging conical opening is 1.5 to 3 times the diameter of the fluid supply hole. A fluid composite nozzle unit characterized in that: 10 In the fluid composite nozzle unit according to claim 2 or 3, the circular reflection hole with a concave cross section formed in the fluid reflection element of the cylindrical second nozzle has an inner diameter and a depth. The diameter of the mixed fluid ejection hole of the cylindrical second nozzle is selected and formed to be 0.8 to 1.2 times and 1/2 to 1/3 times, respectively, and the diameter of the fluid reflecting element is A composite fluid nozzle unit, characterized in that the maximum outer diameter is selected to be 1.6 times or less the diameter of the mixed fluid ejection hole of the cylindrical second nozzle. 11. In the fluid composite nozzle unit according to claim 2, pressurized air or steam is introduced from the inlet of the cylindrical first nozzle, and liquid fuel and water or chemical addition are introduced from the fluid supply hole. A fluid composite nozzle characterized in that the atomized fuel mixed fluid is jetted from the mixed fluid jetting port of the cylindrical second nozzle by supplying a liquid, and is formed in a nozzle part of a low pollution combustion device. unit. 12. In the fluid composite nozzle unit according to claim 2, the liquid fuel is introduced under pressure from the inlet opening of the cylindrical first nozzle, and the waste liquid is supplied from the fluid supply hole. 1. A fluid composite nozzle unit characterized in that a spray stream of atomized combustible waste liquid is dispersed and formed in a nozzle portion of a waste liquid treatment device from a mixed fluid spouting port of a cylindrical second nozzle. 13. In the fluid composite nozzle unit according to claim 2, by introducing a liquid flow under pressure from the inlet opening of the cylindrical first nozzle and supplying a gas flow from the fluid supply hole. A fluid composite nozzle unit characterized in that a nozzle portion of a gas-liquid contact reaction device is formed by ejecting atomized gas-liquid mixed fluid from the mixed fluid spouting port of the cylindrical second nozzle. 14. In the fluid composite nozzle unit according to claim 2, by introducing a pressurized gas flow from the inlet opening of the cylindrical first nozzle and supplying the fluid flow from the fluid supply hole. A fluid composite nozzle unit characterized in that atomized gas-liquid mixed fluid is ejected from the mixed fluid spouting port of the cylindrical second nozzle to form a spray nozzle section in a device for dissolving gas into liquid. 15. In the fluid composite nozzle unit according to claim 2, the nozzle unit is installed in a liquid receiving container of a flotation separation device, and one of the inlet opening of the cylindrical first nozzle or the fluid supply hole mixing in the second cylindrical nozzle by pumping and circulating the receiving liquid in the liquid receiving container and supplying a pressurized gas flow from the other of the inlet opening of the cylindrical first nozzle or the fluid supply hole; 1. A fluid composite nozzle unit comprising a nozzle portion of a flotation separation device that ejects fine gas-liquid mixed fluid into the receiving liquid from a fluid spout to cause flotation separation by the fine gas particles.