JP3382573B2 - Two-fluid nozzle - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-fluid nozzle, and more particularly to atomizing a gas-liquid mixed mist obtained by mixing air and water or an inert gas and water. It is preferably used for cooling high-temperature gas generated in incinerators, melting furnaces, electric furnaces, and heating furnaces, for cooling aluminum extrusion rolls, ferrous / non-ferrous rolling rolls, refractories of steelmaking equipment, and the like.

[0002]

2. Description of the Related Art In a two-fluid nozzle used for cooling of this kind, it is important to atomize liquid droplets in order to improve cooling efficiency, and the object to be sprayed is cooled without causing wetting. In order to achieve
It is necessary to do the following. For example, in a refuse incinerator, the incineration temperature is 800 ° C or higher, and 1200 ° C to 1
It is said that it is preferable to raise the temperature to 300 ° C. Therefore, the waste gas generated during incineration also becomes extremely hot, and it is necessary to cool it to approximately 150 ° C, which can suppress the generation of dioxins. Therefore, the temperature control tower (temperature control tower or cooling tower) connected to the refuse incinerator is required. A nozzle is also installed in the tower) to spray the cooling liquid or cooling water onto the waste gas. This cooling liquid or cooling water spray must be atomized in order to prevent incineration ash and wetting of the dust collector and increase the cooling efficiency of the gas so as not to increase the running cost. A two-fluid nozzle that ejects the gas-liquid mixed mist is used.

As a cooling device for this type of incinerator waste gas,
A device shown in FIG. 7 is proposed in Japanese Patent Laid-Open No. 10-267255, and a cooling liquid spray nozzle 2 composed of a two-fluid nozzle is installed in a temperature reducing tower 1 communicating with an incinerator. As this cooling liquid spray nozzle 2, there is a patent No. 2524379.
The nozzle and the like shown in FIG.

The nozzle 2 has a double-tube structure, and the cooling liquid (water) is supplied to the central flow path 4 of the inner cylinder 3 and the pressurized air is supplied to the outer annular flow path 6 between the inner cylinder 3 and the outer cylinder 5. It is supplied, and the compressed air is swirled out from the tapered injection port at the tip while swirling around the cooling liquid to collide and mix the cooling liquid and the compressed air to atomize the cooling liquid, and the cooling tower The incinerator exhaust gas introduced in 1 is cooled. Specifically, in the nozzle 2 ′ shown in FIGS. 8A and 8B of Japanese Patent No. 2524379, a slit 3a that gives a swirling flow to the compressed air is formed on the inclined surface of the tip of the inner cylinder 3.

As described above, in the nozzle shown in FIG. 8, the slits swirl the pressurized air to collide and mix with the water. Further, in the nozzle 2 shown in FIG. 7, although the specific structure of the nozzle is not disclosed, the cooling liquid ejected from the center is also ejected while swirling, and the pressure air around the outer periphery is also swirling ejected. It is said that they are mixed by collision with and atomized. That is, in each of the nozzles, pressurized air is swirled toward the outer periphery of the cooling liquid jetted from the center while being swirled from the jet port of the tapered structure, and is collided and mixed with the cooling liquid.

[0006]

In the above structure, it is described that the pressurized air on the outer periphery is swirled to collide and mix with the cooling liquid (water) at the center to atomize the droplets. However, as a result of various experiments by the applicant,
When the pressurized air is jetted from the tip of the tapered structure while giving a swirl flow to the pressurized air on the outer circumference, the maximum particle diameter of the droplet is 15
It was recognized that it is difficult to set the thickness to 0 μm or less.

The reason why the above atomization cannot be achieved is that the swirling flow is generated by passing the pressurized air through the slit in the vicinity of the injection port of the tapered structure having a small passage cross-section, so that the flow rate of the pressurized air decreases and It is thought that this is because the distribution of the amount is not uniform. Moreover, since the cooling liquid and the pressurized air are mixed only once by collision, the degree of atomization is low and the spray becomes coarse.

[0008] As described above, when the degree of atomization is low and the droplets are large, there is a problem that the incineration ash adhering to the inner wall of the temperature reducing tower becomes wet and becomes a slurry, and a dust collector (bug that passes waste gas) is used. The filter will get wet, the dust collector will be replaced more frequently, and the running cost for maintenance will increase. If atomization is not achieved, the waste gas is not uniformly cooled, and it is difficult to efficiently cool the waste gas to near 150 ° C. and suppress the generation of dioquins.

The present invention has been made in view of the above problems, and an object thereof is to provide a two-fluid nozzle capable of atomizing a gas-liquid mixed mist and spraying fine particles.

[0010]

To solve the above problems, the present invention provides a triple cylinder having an inner cylinder, a middle cylinder, and an outer cylinder,
The hollow part of the inner cylinder is the central air flow path, the intermediate annular flow path between the inner cylinder and the middle cylinder is the liquid flow path, the outer annular flow path between the middle cylinder and the outer cylinder is the outer air flow path, and the liquid is A means for swirling the liquid is provided in the flow passage, and the liquid is made into a swirling flow to primary atomize the liquid, and the swirling flow liquid is sequentially collided with the air flowing through the central air flow passage and the outer air flow passage. (EN) A two-fluid nozzle configured to inject a gas-liquid mixed mist from an injection port provided at the tip of an outer cylinder after mixing and performing secondary atomization and tertiary atomization.

In the two-fluid nozzle having the above structure, a triple cylinder is provided with air in the center, liquid in the outer periphery, and air in the outer periphery, and the air is supplied from both the center and the outer periphery of the liquid to be annularly supplied. First, the liquid is first swirled in the liquid flow path to perform primary atomization, then collide with the air in the center to secondary atomize it into a gas-liquid mixed fluid, and finally, this gas-liquid The mixed fluid is collided with the air on the outer peripheral side to be atomized into tertiary particles and sprayed. Alternatively, the swirling liquid collides with the air on the outer peripheral side to secondary atomize, and then collides with the central air to tertiary atomize. As described above, since the liquid droplets are atomized in three stages, atomization can be promoted. Further, unlike the conventional example as described above, since the liquid is swirled but the air is not swirled, atomization is not reduced due to the decrease of the air amount and the variation of the air distribution.

An air supply pipe is connected to the inflow ports of the base end side openings of the central air flow passage and the outer air flow passage, and the air supply pipe is connected to a compressor or a blower (blower) so that compressed air from the compressor is compressed. Alternatively, the pressurized air from the blower is circulated in the central air passage or the outer air passage, and the air is not swirled in the air passage extending from the inflow port to the injection port at the tip.

Compressed air from a compressor may be used as the above-mentioned air, but compressed air from a blower can be used because atomization of the liquid can be achieved without using compressed air. With a blower,
Both the running cost and the initial cost can be significantly reduced as compared with the case of using a compressor. The compressed air from the compressor has an air pressure of 0.3 to 0.5 MPa, and the compressed air from the blower has an air pressure of 0.02 to 0.1 MPa.

It should be noted that either the central air passage or the outer air passage is connected to a compressor to introduce compressed air, and the other is connected to a blower to introduce pressurized air. Good.

In the liquid flow path, the inflow port of the base end side opening is connected to a liquid supply pipe, the liquid supply pipe is connected to a liquid tank via a pump, and a pressurized liquid is supplied to the liquid flow path. It is distributed. A communication channel that communicates with the central air channel or the outer air channel is provided at the tip of the liquid channel, and the communication channel has a swirling shape, and the liquid is swirled and flows out to the central air channel or the outer air channel. The air flowing through the air passage is collided and mixed. The liquid pressure is 0.2 to 2.0 MPa when compressed air is used, and 0.05 to 2.0 MPa when compressed air from a blower is used. Water is preferably used as the liquid, but it is selected according to the application, and for cooling the waste gas of the incinerator, the treated waste liquid from the equipment attached to the incinerator may be reused.

Specifically, the first two-fluid nozzle of the present invention is provided with an opening located on the same line along the axis line on the tip side of the inner cylinder, the middle cylinder, and the outer cylinder, and serves as an injection port. The inner cylinder opening is located inside the outer cylinder opening, the inner cylinder opening is located inside the inner cylinder opening, and the tip end surface of the inner cylinder is brought into contact with the step portion of the middle cylinder. A groove serving as a liquid swirling communication flow path is provided in the contact portion, the opening of the tip end surface of the inner cylinder is communicated with the hollow part of the middle cylinder, and the inner cylinder hollow part is opened from the inner cylinder hollow part where the liquid swirling communication flow path is opened. The second mixing chamber is provided between the front end of the middle cylinder and the front end of the outer cylinder, and the inner cylinder is provided with an orifice opening to the first mixing chamber. The liquid is swirled from the flow channel through the flow channel to flow into the first mixing chamber while primary atomizing, and the liquid is swirled in the central mixing chamber. Collides with the air from the passage to the secondary atomized, from the distal end opening of the middle cylinder of the gas-liquid mixed fluid second
The mixture is made to flow into the mixing chamber and collide with the air in the outer air flow path to be tertiary atomized, and this gas-liquid mixed fluid is sprayed from the injection port of the outer cylinder.

In the second two-fluid nozzle of the present invention, the inner cylinder, the middle cylinder, and the outer cylinder are provided with openings located on the same line along the axis line at the tip end sides thereof, and the openings of the outer cylinder serving as the injection port are formed. The opening of the middle cylinder is located inside, the opening of the inner cylinder is located inside the opening of the middle cylinder, the tip end surface of the inner cylinder is brought into contact with the stepped portion of the middle cylinder, and the liquid swirls at the corresponding contact portion. A groove serving as a communication channel is provided, and the opening of the tip end surface of the inner cylinder is made to communicate with the distal end side hollow portion of the middle cylinder whose diameter is reduced by the step, and from the inner cylinder hollow portion where the liquid swirling communication channel is opened. The hollow portion of the middle cylinder serves as the first mixing chamber, and the second mixing chamber is provided between the tip of the middle cylinder and the tip of the outer cylinder. Further, the inner cylinder has an orifice that opens to the first mixing chamber. A liquid is swirled through the liquid swirling communication flow path from the liquid flow path to flow into the first mixing chamber while being atomized into primary particles. , In the first mixing chamber to collide with air from the central air passage to be secondary atomized, and the gas-liquid mixed fluid is caused to flow into the second mixing chamber from the tip opening of the middle cylinder to form air in the outer air passage. It is configured to collide and atomize into third particles, and the gas-liquid mixed fluid is sprayed from the injection port of the outer cylinder. A swirl flow may be applied to the liquid by providing a swirl flow generating member such as a whirler in the liquid flow path adjacent to the first mixing chamber.

Compared with the case where compressed air is supplied from the compressor, the tip openings of the inner cylinder, the middle cylinder, and the outer cylinder in the case where pressurized air is supplied from the blower to the central air flow path and the outer air flow path as compared with the case where compressed air is supplied from the compressor. The tip opening of the inner cylinder is 1-2 times larger, the tip opening of the middle cylinder is 1-2 times larger, and the tip opening of the outer cylinder is 2-4 times larger.

As described above, when the air flow rate is increased, even if the compressed air from the blower, which has a lower air pressure than the compressed air from the compressor, is used, the maximum particle diameter can be increased by atomizing the droplets in the above three stages. Can be atomized to an extent that does not cause wetting of 150 μm or less. Therefore, the cooling efficiency of the waste gas by the gas-liquid mixed mist can be maintained at the same level as when the compressor is used, and the use of the blower can reduce the running cost.

As described above, the first and second nozzles also first swirl the liquid to atomize it, then collide and mix it with the center air to atomize it, and then collide and mix it with the outside air. The droplets can be made into ultrafine particles because the atomization is attempted and the atomization is performed three times in total. Therefore, the maximum particle size can be 150 μm or less not only when the liquid is mixed with the compressed air from the compressor but also when it is mixed with the low-pressure compressed air from the blower.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a two-fluid nozzle according to the present invention will be described below with reference to the drawings. 1A and 1B show an example of use of the two-fluid nozzle of the present invention, which is used for cooling a cold rolling roll 10 installed in a casting facility. A liquid (water) supply main pipe 12 and an air supply main pipe 13 are arranged in parallel over the entire length of the roll 10 in the axial direction, nozzles 11 are attached to the respective branch pipes 12a of the liquid supply main pipe 12, and the liquid of each nozzle 11 described later is described. In addition to supplying water to the flow passages, air is supplied from the branch pipe 13a of the main air supply pipe 13 to the air flow passages of the nozzles 11. Water supply main pipe 12
Is connected to a liquid tank 15 via a pump 14 to supply water of a required pressure to each nozzle 11, and an air supply main pipe 13 is an air source 1 composed of a compressor or a blower.
6 is connected to supply air of a required pressure to each nozzle 11.

2 and 3 show the nozzle 1 of the first embodiment.
1 and the nozzle 11 has the structure of the first nozzle. Low pressure air is supplied to the nozzle 11 of the first embodiment from a blower as pressure air.

As shown in FIG. 2, the nozzle 11 has an inner cylinder 2
The inner cylinder 2 has a triple-cylinder structure including 0, a middle cylinder 21, and an outer cylinder 22.
0 is formed by connecting the base end side cylinder 23 and the tip end side cylinder 24. The hollow portion of the inner cylinder 20 is connected to the central air passage 25, the inner cylinder 20.
The intermediate annular flow path between the intermediate cylinder 21 and the middle cylinder 21 is defined by the liquid flow path 26 and the middle cylinder 2.
The outer annular flow passage between 1 and the outer cylinder 22 is an outer air flow passage 27. The base end side opening of the outer air flow passage 27 and the base end side opening of the central air flow passage 25 are connected to the air supply main pipe 13 so that low pressure air is introduced from an air pressure source 16 composed of a blower. Further, the water supply main pipe 12 is connected to the base end side opening of the ring-shaped liquid flow path 26 so that the water pressurized from the liquid tank 15 via the pump 14 can flow in.

The tip side tube 24 of the inner tube 20, the middle tube 21,
A tip portion 20b having openings 20a, 21a, 22a located on the same line along the axis L on the tip side of the outer cylinder 22,
The opening 2 of the outer cylinder 22 which is provided with 21b and 22b and serves as an injection port
The opening 21a of the middle cylinder 21 is located inside 2b, and the opening 20a of the inner cylinder 20 is located inside the middle cylinder opening 21a.

The tip side tube 24 of the inner tube 20 is a base end side tube 23.
The distal end of the cylindrical portion screwed to and connected to the inner cylindrical opening 20a serves as the inner cylindrical opening 20a, and the diameter of the orifice 24a is reduced in the central portion in the axial direction.
Is provided. As shown in FIG. 2, two concave grooves 24c are formed at substantially opposite positions on the front end surface 24b which is the peripheral edge of the opening 20a of the inner cylinder 20.

The outer peripheral surface of the tip portion 21b of the middle cylinder 21 is conical, and a step 21c is provided therein to provide a hollow portion having a small diameter on the tip end side. The hollow portion serves as a tip opening 20a of the inner cylinder 20. The same diameter is used for communication. The tip opening 21a having a smaller diameter is provided at the tip of the small-diameter hollow portion on the tip side.

The tip end surface 24b of the inner cylinder 20 is brought into contact with the step 21c of the middle cylinder 21, and the gap between the groove 24c and the step 21c is 3 mm.
The individual liquid swirling communication flow paths 28 are provided. This liquid swirling communication flow path 28 opens in the hollow portion on the tip side of the inner cylinder 20, and communicates the hollow portion on the tip side of the inner cylinder 20 with the hollow portion of the middle cylinder 21. Cylinder 20 and middle cylinder 2
The hollow portion at the tip of No. 1 is the first mixing chamber 29.

The front end portion 21b of the middle cylinder 21 and a front end portion 22b of the outer cylinder 22 are externally fitted to each other with a wide space left therebetween, and the second mixing chamber 30 is provided between the front end closing portions 21b and 22b of the middle cylinder and the outer cylinder. Is formed. The second mixing chamber 30 communicates with the annular outer air flow passage 27 and has an opening 22 serving as an injection port at the center of the tip.
a is located.

In the nozzle 11 having the above structure, first,
The water that has flowed into the liquid flow path 26 is forcibly swirled when passing through the liquid swirling communication flow path 28, and flows into the first mixing chamber 29 as a swirling flow. This turning causes primary atomization of the water. The air from the blower ejected through the orifice 24a of the central air passage 25 collides and mixes with the central portion of the water that has entered the first mixing chamber 29 as a swirling flow. The secondary mixing of the droplets is performed by this collision mixing, and the middle cylinder 2
It spouts from the first opening 21a into the second mixing chamber 30.

This secondary atomized gas-liquid mixed fluid is the second
In the mixing chamber 30, the air from the blower flowing in from the outer air flow passage 27 collides and mixes from the outer peripheral side. In this way, the gas-liquid mixing mist that has been subjected to tertiary atomization in the second mixing chamber 30 is ejected from the opening 22 a that serves as the ejection port of the outer cylinder 22. In particular, since the second mixing chamber 30 is a wide space, the air flowing in from the outer air flow passage 27 collides and mixes uniformly with the gas-liquid mixed fluid flowing in from the opening 21a from the outer periphery, and In addition, since the gas-liquid mixed fluid is swirling, the droplets can be uniformly atomized.

In the nozzle 11 of the first embodiment, low pressure air of 0.02 to 0.1 MPa supplied from a blower is used as the pressure air, but the air flow rate is increased and
After the water is swirled to be primary atomized, it is collided and mixed with air from the blower again to atomize the droplets in three stages, so that the maximum particle diameter of the droplets can be set to 150 μm. When the blower is used as described above, the running cost can be significantly reduced as compared with the case where the compressor is used.

As a result of an experiment using the two-fluid nozzle of the first embodiment, the air / water ratio (air amount / water amount) was 200 to 1
000, and the air pressure from the blower is 0.02-0.1
It was possible to atomize the particles to a particle size of 150 μm to 50 μm under the conditions that the pressure was MPa, the water pressure was 0.05 to 2.0 MPa, and the spray flow rate was 20 to 1000 liters / hour. From this experimental result, it was confirmed that the use of the nozzle of the present invention enables the maximum particle size to be 150 μm or less, which is a required value, even when the low pressure air from the blower is used.

FIGS. 4 and 5A and 5B show the nozzle 11 of the second embodiment, and the nozzle 11 has the structure of the second nozzle. Compressed air from a compressor is used as the pressurized air in the nozzle 11 of the second embodiment.

The nozzle 11 of the second embodiment has the same basic structure as the nozzle of the first embodiment, and the same members will be denoted by the same reference numerals.
The inner cylinder 20 is formed by connecting a base end side cylinder 23 and a tip end side cylinder 24 to each other. The hollow portion of the inner cylinder 20 is provided with the central air passage 25, the inner cylinder 20 and the middle cylinder 21.
The intermediate annular flow path between the liquid flow path 26, the middle cylinder 21 and the outer cylinder 2
The outer annular flow path between the two is defined as the outer air flow path 27.
Compressed air is made to flow from an air pressure source 18 composed of a compressor into the base end side opening 27a of the outer air flow passage 27 and the base end side opening 25a of the central air flow passage 25. Further, pressurized water is made to flow into the base end side opening 26a of the annular liquid channel 26.

The tip side tube 24 of the inner tube 20, the middle tube 21,
A tip portion 20b having openings 20a, 21a, 22a located on the same line along the axis L on the tip side of the outer cylinder 22,
The opening 2 of the outer cylinder 22 which is provided with 21b and 22b and serves as an injection port
The opening 21a of the middle cylinder 21 is located inside 2b, and the opening 20a of the inner cylinder 20 is located inside the middle cylinder opening 21a.

The tip side cylinder 24 of the inner cylinder 20 is shown in FIG.
In the shape shown in (B), the distal end of the cylindrical portion 23a screwed to and connected to the proximal cylinder 23 serves as the inner cylindrical opening 20a, and a flange portion 24b is provided on the outer periphery of the distal end. An inclined surface 24d is formed on the outer periphery of the tip end surface 24c of the flange portion 24b, and concave grooves 24e are formed by inclining the inclined surface 24d in a swivel shape toward the center side at equal intervals in the circumferential direction. 3 are formed. This tip side cylinder 24
The hollow portion 24f serving as the central air flow path has a smaller diameter than the hollow portion 23a of the proximal side cylinder 23.

The front end closing portion 21b of the middle cylinder 21 has a substantially conical cylindrical shape inclined toward the front end side, the inclined surface 21c is brought into contact with the inclined surface 24d of the inner cylinder, and the groove 24 is provided at the corresponding contact portion.
Three liquid swirling communication channels 28 made of e are provided.

A large conical first mixing chamber 29 is provided between the front end closing portion 20b formed of the flange portion 24b of the inner cylinder 20 and the front end portion 21b of the middle cylinder 21, and the bottom surface side of the first mixing chamber 29 is provided. The liquid swirling communication channel 28 is opened, and the opening 21a of the middle cylinder is located at the center of the tip end side.

The distal end portion 22b of the outer cylinder 22 is externally fitted to the distal end closing portion 21b of the middle cylinder 21 with a wide space therebetween, and the second mixing chamber is provided between the distal end closing portions 21b and 22b of the middle cylinder and the outer cylinder. Thirty
Is formed. The second mixing chamber 30 communicates with the annular outer air flow passage 27 and has an opening 22a serving as an injection port located at the center of the tip.

In the nozzle 11 having the above structure, first,
The water flowing into the liquid flow path 26 is forcibly swirled when passing through the liquid swirling communication flow path 28 on the tip side, and the first mixing chamber 29
It flows in a swirling flow into. This turning causes primary atomization of the water. The compressed air ejected from the central air flow passage 25 collides and mixes with the central portion of the water that has entered the first mixing chamber 29 as a swirl flow. The secondary atomization of the liquid droplets is performed by this collision mixing, and the second liquid is atomized from the opening 21a of the middle cylinder 21.
It spouts into the mixing chamber 30.

This secondary atomized gas-liquid mixed fluid is the second
In the mixing chamber 30, the compressed air flowing in from the outer air flow passage 27 collides and mixes from the outer peripheral side. In this way, the gas-liquid mixing mist that has been subjected to tertiary atomization in the second mixing chamber 30 is ejected from the opening 22 a that serves as the ejection port of the outer cylinder 22. In particular, since the second mixing chamber 19 is a large space, the compressed air flowing in from the outer air flow passage 27 collides and mixes uniformly with the gas-liquid mixed fluid flowing in from the opening 21a from the outer periphery, Moreover, since the gas-liquid mixed fluid is swirling, the droplets can be uniformly atomized.

When an experiment was conducted using the two-fluid nozzle of the second embodiment, the air / water ratio (air amount / water amount) was 100 to 50.
0, the pressure of compressed air is 0.3 to 0.5 MPa, the water pressure is 0.2 to 2.0 MPa, and the spray flow rate is 20 to 100.
Under the condition of 0 liter / hour, the particle size is 15
The particles could be atomized to 0 μm to 50 μm. Specifically, the maximum particle size is 110 to 150 μm when the air / water ratio is 150 and the compressed air pressure is 0.4 MPa, and the maximum particle size is 500 when the air / water ratio is 500 and the compressed air pressure is 0.4 MPa. It was 90 μn to 110 μm. From this experimental result, it was difficult to set the maximum particle diameter to 150 μm or less in the conventional two-fluid nozzle using the compressed air amount,
The nozzle of the present invention promotes atomization to increase the maximum particle size to 1
It was confirmed that the thickness could be 50 μm or less. It was also confirmed that the maximum particle size can be 150 μm or less even if the compressed air amount is reduced by setting the air / water ratio to 150, and the line cost can be reduced accordingly.

The nozzle 11 of the third embodiment shown in FIG. 6 uses low pressure air from a blower as the pressure air. Third
The structure of the nozzle 11 of the embodiment is basically the same as that shown in FIGS.
The second nozzle has the same configuration as that of the second embodiment shown in FIG. 3, but the cross-sectional area of the air flow path and the cross-sectional areas of the tip openings 20a, 21a, 22a of the inner cylinder 20, the middle cylinder 21, and the outer cylinder 22 are the same. Is the second embodiment or more.

That is, the opening 20 of the inner cylinder 20 of the second embodiment.
With respect to the diameter of a, the opening 20 of the inner cylinder 20 of the third embodiment
The diameter of a is 1 to 2 times. Further, the diameter of the opening 21a of the middle cylinder 21 of the third embodiment is 1 to 2 times the diameter of the opening 21a of the middle cylinder 21 of the second embodiment. Further, the diameter of the opening 22a of the outer cylinder 22 of the third embodiment is 2 compared to the diameter of the opening 22a of the outer cylinder 22 of the second embodiment.
~ 4 times.

Further, the inner cylinder 20 is formed by one continuous cylinder, and the central air flow path 25 in the hollow portion has the same diameter from the inflow port 25a on the base end side to the tip end opening 20a.
The central air flow rate is increased by setting the central air flow path 25 larger than that of the second embodiment. Further, a flange portion 24c ′ is integrally formed from the tip of the inner cylinder 20, a swirl-shaped groove 24e ′ is provided, and a liquid swirling communication flow path 28 ′ provided between the inner cylinder 20 and the middle cylinder 21 has a circumferential angle of 90 degrees. Four pieces are formed at intervals. The outer air flow passage 27 between the middle cylinder 21 and the outer cylinder 22 also has a larger cross-sectional area than the outer air flow passage 27 of the second embodiment to increase the outer air flow rate. Other configurations are second
Since it is the same as the embodiment, the same reference numerals are given and the description is omitted.

In the nozzle 11 of the third embodiment, low pressure air of 0.02 to 0.1 MPa supplied from a blower is used as the pressure air as in the first embodiment, but the air flow rate is increased, In addition, as in the first and second embodiments, water is swirled to perform primary atomization, and then collision mixing with pressurized air is performed twice to atomize the liquid droplets in three stages. The maximum particle size of the drops can be 150 μm.

Using the two-fluid nozzle of the third embodiment,
Similar to the first embodiment, the air / water ratio (air amount / water amount) is set to 20.
0 to 1000, and the air pressure from the blower is 0.02
Under the conditions of 0.1 MPa, a water pressure of 0.05 to 2.0 MPa, and a spray flow rate of 20 to 1000 liters / hour, the particle size could be reduced to 150 μm to 50 μm.

In each of the above-mentioned embodiments, the nozzle 11 is used for cooling the cold rolling rolls, but it is used for cooling the waste gas of the incinerator, for example, by mounting it in the cooling tower (cooling tower). It goes without saying that it is preferably used for In particular, when used for cooling the waste gas, the waste gas may flow into the inside of the nozzle, but the nozzle of the present invention has a triple tube structure and ejects the pressure air from the central portion.
Waste gas is less likely to flow into the nozzle. Therefore, it is possible to prevent the waste gas from flowing into the nozzle and causing corrosion inside the nozzle.

[0049]

As is apparent from the above description, according to the two-fluid nozzle of the present invention, the liquid is swirled to mix it with the gas to perform the primary atomization, and thereafter, the air in the central air passage or Compared with the conventional nozzle in which the air is swirled and then mixed with the liquid only once because the secondary atomization and the tertiary atomization are performed by collision-mixing with the air in the outer air channel in two stages. By doing so, atomization of the liquid droplets can be further promoted.

As described above, since the water droplets can be atomized as compared with the conventional nozzle, the air from the low pressure blower can be used as the pressure air, and even if the air from the blower is used, the high temperature gas When sprayed for cooling, the sprayed product does not get wet. Therefore, for example, when used for cooling the waste gas, does not cause wetting of the incineration ash, and,
It is possible to reduce the number of replacements due to the wetting of the air dust collector, and it is possible to reduce the maintenance cost.

Furthermore, when compressed air is used, atomization can be promoted and the maximum particle diameter can be set to 150 μm or less, as compared with the conventional two-fluid nozzle using compressed air. Furthermore, since the required ultrafine particles can be obtained even if the spray flow rate is increased, the spray flow rate can be increased to enhance the cooling efficiency. That is, when used for cooling a high temperature gas, the temperature can be rapidly lowered to the required temperature, and the evaporation time can be shortened. Therefore, when used in an incinerator, the height and diameter of the temperature reducing tower can be reduced, and the initial cost can also be reduced.

[Brief description of drawings]

1A and 1B are schematic views showing an example of use of the two-fluid nozzle of the present invention.

FIG. 2 is a cross-sectional view of the nozzle according to the first embodiment.

FIG. 3 is a side view of a tip side inner cylinder used in the nozzle of the first embodiment.

FIG. 4 is a sectional view of a nozzle according to a second embodiment.

FIG. 5 shows a distal end side inner cylinder used in the second embodiment,
(A) is a sectional view and (B) is a side view.

FIG. 6 is a sectional view of a nozzle according to a third embodiment.

FIG. 7 is a diagram showing a conventional example.

8A and 8B are drawings showing a conventional nozzle.

[Explanation of symbols]

11 nozzles 20 inner cylinder 21 Middle tube 22 Outer cylinder 20a, 21a, 22a openings 20b, 21b, 22b Tip closing part 25 central air flow path 26 Liquid flow path 27 Outside air flow path 28 Liquid swirling communication flow path 29 First mixing chamber 30 Second mixing chamber

─────────────────────────────────────────────────── ─── Continuation of front page (56) Bibliography Sho 63-126056 (JP, U) Japanese Patent Publication Sho 50-6362 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) B05B 7/00-7/32

Claims (5)

(57) [Claims] 1. A triple cylinder including an inner cylinder, a middle cylinder, and an outer cylinder, wherein a hollow portion of the inner cylinder is a central air passage, and an intermediate annular passage between the inner cylinder and the middle cylinder is a liquid passage. The outer annular flow path between the cylinder and the outer cylinder is an outer air flow path, a means for swirling the liquid is provided in the liquid flow path, and the liquid is swirled to be primary atomized, and the swirl flow is formed. Is subjected to secondary atomization and tertiary atomization by sequentially colliding and mixing with the air flowing in the central air flow channel and the outer air flow channel, and then gas-liquid mixing from the injection port provided at the tip of the outer cylinder. A two-fluid nozzle configured to eject mist. 2. An air supply pipe is connected to the inlets of the base end side openings of the central air flow passage and the outer air flow passage, and the air supply pipe is connected to a compressor or a blower so that compressed air from the compressor or The compressed air from a blower is circulated to the central air passage or the outer air passage, and the air is not swirled in the air flow passage extending from the inflow port to the injection port at the tip. Fluid nozzle. 3. The inner cylinder, the middle cylinder, and the outer cylinder are provided with openings located on the same line along the axis line at the front end side, and the opening of the middle cylinder is located inside the opening of the outer cylinder serving as the injection port. The inner cylinder opening is positioned inside the middle cylinder opening, and the tip end surface of the inner cylinder is brought into contact with the step portion of the middle cylinder,
A groove serving as a liquid swirling communication channel is provided in the abutting portion, and the opening of the front end surface of the inner cylinder is communicated with the distal end side hollow portion of the middle cylinder whose diameter is reduced by the step, and the liquid swirling communication channel is opened. The hollow portion of the inner cylinder to the hollow portion of the middle cylinder serves as the first mixing chamber, and the second mixing chamber is provided between the tip portion of the middle cylinder and the tip portion of the outer cylinder. An orifice that opens in the mixing chamber is provided, and the liquid is swirled through the liquid swirling communication channel from the liquid channel to flow into the first mixing chamber while being atomized, and the air from the central air passage in the first mixing chamber is discharged. The gas-liquid mixed fluid is made into secondary atomization by flowing into the second mixing chamber through the tip opening of the middle cylinder and collided with the air in the outer air passage to be thirdly atomized. The structure according to claim 1 or 2, wherein the composition is sprayed from the injection port of the outer cylinder. Fluid nozzle. 4. The inner cylinder, the middle cylinder, and the outer cylinder are provided at the front end with openings located on the same line along the axis, and the middle cylinder is opened inside the opening of the outer cylinder serving as the injection port. Position, the opening of the inner cylinder is located inside the opening of the middle cylinder, the peripheral edge of the front end opening of the middle cylinder is inclined toward the front end side, and the inclined surface is provided with a projection on the outer periphery of the front end of the inner cylinder. The flange portion is brought into contact, a groove serving as a liquid swirling communication channel is provided at the corresponding contact portion, and the liquid swirling communication channel is opened between the tip portion of the inner cylinder and the tip portion of the middle cylinder. While providing the first mixing chamber, the second mixing chamber is provided between the front end of the middle cylinder and the front end of the outer cylinder, and the liquid is swirled through the liquid swirling communication flow path from the liquid flow path while primary atomization is performed. The gas and liquid are made to flow into the first mixing chamber and collide with the air from the central air passage in the first mixing chamber to be secondary atomized. A structure in which the mixed fluid is caused to flow into the second mixing chamber from the tip opening of the middle cylinder, collides with the air in the outer air flow path to be thirdly atomized, and the gas-liquid mixed fluid is sprayed from the injection port of the outer cylinder. The two-fluid nozzle according to claim 1 or 2. 5. The front end openings of the inner cylinder, the middle cylinder, and the outer cylinder in the case of supplying pressurized air from a blower to the central air passage and the outer air passage, respectively, when compressed air is supplied from a compressor. In comparison, the tip opening of the inner cylinder is 1-2 times, and the tip opening of the middle cylinder is 1-2.
5. The two-fluid nozzle according to any one of claims 1 to 4, wherein the tip opening of the outer cylinder has a size of 2 to 4 times.