JP2000107651A - Two-fluid nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To atomize liquid without increasing a gas-to-water ratio and to keep the atomization on the increase in an atomized flow by turning the liquid flowing through a flow passage along the axis line of a nozzle body by a whirler, and throttling it by an orifice to cause gas to flow in from the outer periphery to spray the liquid as mixed fluid with the gas. SOLUTION: Liquid fed along the axis line of a flow passage 25a is made a turning flow by a whirler 27 and also it is hit against the inner peripheral surface of the flow passage 25a to atomize it. Next, after it flows to an orifice 28 and undergoes diameter contraction, it undergoes diameter expansion to the side of a gas inflow chamber 29 and is jetted. At this time, to the gas inflow chamber 29, compressed air is fed through a gas inflow paths 32A and 31, and a gas inflow hole 30, and it is hit against and mixed with the liquid jetted into the gas inflow chamber 29. By this, it is turned into gas-liquid mixed liquid in which particle diameters of water droplets are approximately uniformalized in both the inside and outside, and it flows into a gas-liquid mixing chamber 33 and is accelerated and is sprayed from a jetting hole 38 through a diameter contraction chamber 35 and a jetting port part 36. In this way, the liquid can be atomized without increasing the gas-to-water ratio.

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 a method for atomizing a gas-liquid mixture mist obtained by mixing air and water, for cooling high-temperature gas generated in a refuse incinerator. It is preferably used.

[0002]

2. Description of the Related Art In a refuse incinerator, the incineration temperature is 80.
It is said that it is preferable to increase the temperature to 0 ° C. or higher, and further to 1200 ° C. to 1300 ° C. Therefore, the gas generated at the time of incineration becomes very high temperature and needs to be cooled to about 150 ° C. after incineration. Therefore, a nozzle is installed in a refuse incinerator, and a cooling spray is injected into the gas. This cooling spray prevents incineration ash and dust collectors from getting wet,
In order not to increase the running cost by increasing the gas cooling efficiency, it is necessary to atomize the spray. Therefore, a two-fluid nozzle that jets a gas-liquid mixed mist obtained by mixing air with water is used.

As a two-fluid nozzle of this type, a nozzle shown in FIG. 8 has been provided in Japanese Patent Application Laid-Open No. 60-41565. In the nozzle, a liquid flow path 2 is provided along the axis of the nozzle body 1, and an annular air flow path 4 is provided outside the peripheral wall 3 of the gas-liquid mixing chamber 2 a of the liquid flow path 2, and the peripheral wall 3 Holes 3a are provided at intervals along the spiral line, and gas is mixed by flowing air from the holes 3a into the gas-liquid mixing chamber 2a, and a gas-liquid mixed mist is injected from the injection port 5. Like that.

[0004] In the above nozzle, the holes 3a are arranged spirally so that the holes 3a are uniformly arranged over the entire circumference.
It is characterized in that air flows into and mixes the liquid inside from all around. The atomization of the gas-liquid mixture is performed only by once colliding the air flowing into the liquid from the outer periphery in the gas-liquid mixing chamber 2a, and the degree of atomization of the gas-liquid mixture is low.

On the other hand, in order to make the gas-liquid mixture finer, the present applicant has previously provided a nozzle shown in FIG. 9 in Japanese Patent Application Laid-Open No. Hei 7-124502. This nozzle collides and supplies the liquid from the liquid supply path 8 to the outer periphery of the air supplied from the air supply path 7 at the center of the supply end side of the nozzle body 6, from the mixing section 9 to the injection port 10. Are provided with wall surfaces 11a and 11b against which the mixed fluid collides.

[0006]

The above-mentioned nozzle collides with the multi-stage wall surface until the mixed fluid is mixed in the mixing section 9 on the supply end side and the mixed fluid is sprayed from the injection port 10, and a plurality of collisions occur. Since it is repeated twice, water droplets can be made finer than the nozzle shown in FIG.

However, by merely increasing the number of collisions to achieve atomization as described above, in order to make the maximum particle diameter smaller than 200 μm, the air-water ratio (air amount / water amount) needs to be 200 or more. Further, it is preferable that the water droplet is 150 μm or less.
Must be 00 or more. As described above, in order to increase the air-water ratio, it is necessary to increase the amount of use of the compressed air, and there is a problem that the running cost is increased.

Further, when the spray flow rate is increased, water droplets become larger, and the nozzle shown in FIG.
When it is set to 50, it is necessary to be 200 liters / hour in order to make the maximum particle diameter 150 μm. Recently, the size of refuse incinerators cannot be reduced to the required temperature unless the spray flow rate is increased, but as described above, increasing the spray flow rate increases the particle size and increases wetness. There is a problem that occurs.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a nozzle capable of achieving atomization without increasing the air-water ratio and maintaining atomization even when the spray flow rate is increased. I have.

[0010]

In order to solve the above-mentioned problems, the present invention forms a flow path along an axis from a base end side of a nozzle body to a front end injection side, and supplies a liquid to an inlet of the flow path. In addition to connecting the pipe, a whirler for swirling the liquid and an orifice for restricting the liquid are interposed in the flow path, and a circumferential interval is provided in the circumferential wall of the flow path on the injection side from the arrangement position of the whirler and the orifice. In addition, a gas inflow hole is provided, and a gas annular passage communicating with the outer end of the gas inflow hole is provided, and the gas annular passage is communicated with a gas inflow passage formed in the nozzle body, and the gas flows in along the axis. The present invention provides a two-fluid nozzle configured to swirl a liquid to be swirled by a stirrer and squeeze it with an orifice, and then collide and mix with a gas flowing in from the outer periphery, and spray the mixed fluid from a tip injection port.

The arrangement order of the stirrer and the orifice provided in the flow path is not limited. The orifice is set to the inflow side and the stirrer is set to the injection port side. You may make it mix with the gas which flows in from an outer periphery by collision. The number of the orifices and the number of the orifices may be one, respectively, or may be provided in a plurality of stages.
Further, the gas inflow hole provided on the outer periphery of the flow path may have an opening in contact with the flow path in tangential direction with the flow path, or may be in communication with the flow path at right angles to the flow path. The number of the gas inflow holes is not limited as long as they are formed at a constant pitch in the circumferential direction. When the flow path has a large diameter, it is preferable to increase the number of the gas inflow holes. Further, the gas inflow holes provided in the outer periphery of the flow path may be provided in multiple stages in the axial direction of the flow path.

The whirler is disposed transversely to the flow path, and a plurality of blades protrude from the axis, and the tips of the blades abut the inner circumferential surface of the flow path and pass between the blades. With this flow of the fluid, a swirling flow is forcibly generated. As the whirler, an X-type whirler, a swastika-type whirler, or the like is conventionally used, but any shape may be used.

As described above, by causing the liquid flowing into the flow path of the nozzle body to pass through the whirler, to generate a swirling flow, and to collide with the blades of the whirler and the inner wall of the flow path, first, water droplets can be atomized. . Further, by passing through the orifice, the liquid collides with the wall at the inlet of the orifice and is atomized, and the liquid discharged from the orifice collides with the inner wall on the outlet side at high pressure to be atomized. By causing a gas to flow into the atomized liquid from the outer periphery through the stirrer and the orifice and causing the gas to collide with the liquid, the atomization is promoted and the particle diameter is made uniform. In this way, not only is the gas impinged and mixed into the liquid, but also by passing it through a stirrer and an orifice before that, the atomization can be achieved as compared with the conventional nozzle, and even if the water-to-water ratio is lowered, the spray flow rate is also reduced. Even if it increases, it is possible to maintain the maximum particle diameter of 150 μm or less that does not cause wetting.

In the flow path along the axis of the nozzle body,
It is preferable that the whirler and the orifice are sequentially arranged from the inflow port side to the injection port side, and a gas inflow hole is provided in the flow path inner wall on the outlet side of the orifice. That is, when a gas is supplied from the outer periphery to the liquid diffused out of the orifice and mixed, gas-liquid mixing can be made uniform and water droplets can be made finer.

[0015] Further, a gas-liquid mixing chamber having an enlarged diameter is provided between the flow path from the position where the gas inflow hole is provided to the tip injection port,
A step is provided at the tip side of the gas-liquid mixing chamber to make the reduced diameter chamber continuous, a conical injection port is provided at the tip of the reduced diameter chamber, and a porous injection hole is provided on the outer wall of the injection port section. .

As described above, the gas-liquid mixing chamber is provided on the injection port side from the position where the gas inflow hole is disposed, and when the mixed gas-liquid is passed through the gas-liquid mixing chamber having an enlarged diameter, gas and liquid are mixed in the gas-liquid mixing chamber. The liquid can be uniformly mixed. Further, when the gas-liquid mixture is passed through the gas-liquid mixing chamber to the reduced-diameter chamber, the mixed gas-liquid can again collide with the stepped portion to achieve atomization. In addition, the injection hole provided in the injection port is not limited to a single hole, and may be a single hole. However, when the single hole is used, atomization can be achieved, and when used for gas cooling, the spray range is widened. It is preferable that

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a two-fluid nozzle according to the present invention will be described below with reference to the drawings. As shown in FIG.
The nozzle body 20 includes a base 21, a core 22, and a chip 23. In a state where the core 22 is connected to the tip of the base 21, a base-side cylindrical portion 23 a of the chip 23 is externally fitted and screwed into the base 2.
1, the core 22, and the chip 23 are integrally fixed. In the nozzle body 20 including the base 21, the core 22, and the tip 23, a flow path 25 is formed along the axis L from the base end side (X) to the front end jet side (Y). 25a is connected to the liquid supply pipe 40.

The flow path 25b formed in the base 21 performs a rectifying action on the liquid supplied through a long flow path having a constant diameter. The flow path 25c formed in the core 22 in communication with the flow path 25b is provided with a whirler accommodating portion 26 having substantially the same diameter as the flow path 25b on the inflow end side. The X-type whirler 27 shown in FIGS. 2A and 2B is housed in the whirler housing 26. Note that a swastika type whirler shown in FIGS. 3 and 4 may be used. The whirler may be provided integrally with the base, instead of being provided separately from the base.

An orifice 28 having a small diameter is provided by sequentially reducing the diameter of the orifice 28 toward the injection port side, and a gas inflow chamber 29 having an enlarged diameter is provided at the outlet side of the orifice 28. A gas inflow hole 30 is provided in the peripheral wall of the gas inflow chamber 29 at a constant pitch in the circumferential direction so as to penetrate in the horizontal direction, and a gas annular flow path 31 formed between the core 22 and the chip 23.
Is communicated to. In the core 22, a gas inflow path 32A communicating with the gas annular flow path 31 is formed so as to penetrate in the axial direction, and a gas inflow path 32B formed in communication with the base 21 is formed.
And is continuous. The gas inflow passage 32B communicates with the compressed air supply pipe 41, so that air at a required pressure flows into the gas inflow chamber 29 uniformly from the outer periphery.

A gas-liquid mixing chamber 33 communicating with the gas inflow chamber 29 is formed in the core 22 and the chip 23 so as to have a larger diameter. Further, the tip 23 is provided with a reduced diameter chamber 35 via a step 34 on the injection port side of the gas-liquid mixing chamber 33.
A conical orifice 36 is provided at the tip of the nozzle.
Is provided with a porous injection hole 38 on the outer wall 37 of the slab.

Next, the operation of the nozzle having the above configuration will be described. The liquid (water in the present embodiment) supplied along the axis of the flow path 25a reaches the whirler 27 through the flow path 25a of the base 21. The liquid collides with the blades 27a of the whirler 27 and is swirled by the blades 27a, so that the liquid forms a swirling flow. In addition, the liquid collides with the blades 27a and also collides with the inner peripheral surface of the flow path, whereby water droplets of the liquid are atomized.

The swirling flow of the liquid by the whirler 27 is reduced in diameter and flows into the orifice 28, and is expanded from the outlet of the orifice 28 toward the gas inflow chamber 29 and is ejected. By passing through this orifice 28, water droplets are atomized and ejected.

The compressed air flowing in from the gas inlet hole 30 on the outer periphery collides with the liquid jetted into the gas inlet chamber 29. By this collision mixing, mainly water droplets having a large particle diameter at the outer peripheral portion become water droplets having a small particle diameter, and become substantially equal to water droplets at the central portion. Here, the mixture becomes a gas-liquid mixture, flows into the gas-liquid mixing chamber 33, and the mixing of the gas and the liquid is accelerated in the expanded gas-liquid mixing chamber 33, whereby the gas-liquid is uniformly mixed.

The gas flows from the gas-liquid mixing chamber 33 into the reduced-diameter chamber 35. At this time, the gas-liquid mixture collides with the step portion 34, and again.
In particular, water droplets on the outer periphery are atomized. The gas flows from the reduced diameter chamber 35 into the injection port 36, and the atomized gas-liquid mixture is sprayed from the injection hole 38.

As described above, before the liquid supplied to the flow path 25 along the axis of the nozzle body 20 is ejected from the injection hole 38, the liquid first collides with the whirler 27 and is turned and atomized. In addition, water droplets in the central flow and the peripheral flow are made uniform. This swirling flow is throttled by passing through the orifice 28, and water droplets are atomized and ejected at the outlet side of the orifice 28. Thus, before being mixed with the gas, the liquid is atomized by the stirrer and the orifice. Then, a gas flows into the liquid ejected from the orifice 28 from the outer periphery and is impact-mixed, so that water droplets are further atomized. Then, the gas-liquid mixing chamber 33 achieves uniform mixing of gas and liquid. When the gas flows into the reduced diameter chamber 35, it collides with the stepped portion 34, so that the particles are again atomized. Even when the fuel is injected from the hole 38, the fuel is finally atomized and injected. As described above, since not only the gas is impact-mixed with the liquid to atomize the liquid, but also a large number of means for atomizing the liquid are used in combination, the water droplet is compared with the conventionally provided nozzle. Can be achieved, and ultrafine particles can be sprayed.

Using the two-fluid nozzle of the above embodiment and the conventional two-fluid nozzle shown in FIG. 9, the relationship between the maximum particle diameter and the water / water ratio was tested. The particle diameter was measured at a position 1000 mm away from the injection port of the nozzle. The result is as shown in FIG. 5. In the nozzle of the present embodiment, the maximum particle diameter could be set to 150 μ when the air-water ratio was 150, but in the conventional nozzle, the air-water ratio was 150. As a result, the maximum particle size was 220 μ. In the conventional nozzle, it has been recognized that the air-water ratio needs to be 500 or more in order to make the maximum particle diameter 150 μm.

From the above experimental results, the use of the nozzle of the present invention makes it possible to reduce the maximum particle size to 150 μm or less without increasing the amount of compressed air, and to reduce the amount of compressed air used compared to the conventional nozzle. It has been proved that running costs can be reduced accordingly.

The nozzle of the above embodiment and the conventional nozzle shown in FIG.
The relationship between the maximum particle size and the spray flow rate was tested using the nozzle shown in FIG. Measurement of particle size is 10
The measurement was performed at a position separated by 00 mm. The results are as shown in FIG. 6. In the nozzle of the present invention, the maximum particle diameter could be made 150 μ even when the spray flow rate was 900 liter / hour, but in the conventional nozzle, the maximum particle diameter was made 150 μ. Confirmed that the spray flow rate needed to be 300 liters / hour or less.

From the above experimental results, when the nozzle of the present invention is used, even if the spray flow rate is three times that of the conventional nozzle, the maximum particle diameter can be 150 μm, and the spray flow rate can be increased without increasing the particle diameter. It has been proved that the cooling efficiency can be increased.

FIG. 7 shows another embodiment, in which the gas inflow chamber 2 is provided.
9 are provided in two stages in the axial direction of the flow path, and gas inflow holes 30A and 30B are provided. A plurality of these two-stage gas inlet holes 30A and 30B are provided at a constant pitch in the circumferential direction, similarly to the above-described embodiment.
In this way, a plurality of gas inlet holes are provided at a constant pitch in the circumferential direction, and a plurality of gas inlet holes are also provided in the axial direction, and when the gas flows into the liquid, the collision mixing of the gas and the liquid is further promoted, Gas-liquid mixing can be promoted.

[0031]

As is apparent from the above description, according to the two-fluid nozzle of the present invention, before the liquid is mixed with the gas, the water droplet is atomized in two stages through the stirrer and the orifice. Thereafter, since the particles are collision-mixed with the gas, the atomization can be further promoted as compared with the case where water droplets are atomized only by the conventional collision mixing.

Further, by impinging and mixing the gas-liquid mixture produced by impinging and mixing the gas with the liquid on the step portion of the flow path, the water droplets can be atomized again.

As described above, since the water droplets can be atomized as compared with the conventional nozzle, when sprayed for cooling a high-temperature gas, the incineration ash does not cause wetting, and replacement due to the wetting of the air dust collector occurs. The number of times can be reduced, and the maintenance cost can be reduced.

Furthermore, the required ultrafine particles can be obtained without increasing the amount of compressed air to be mixed, so that the amount of air used can be reduced and the running cost can be reduced. Furthermore, since the required ultrafine particles can be obtained even if the spray flow rate is increased, the cooling efficiency can be increased by increasing the spray flow rate. That is, when used for cooling a high-temperature gas, the temperature can be rapidly lowered to a required temperature, and the evaporation time can be shortened. As a result, the height of the cooling tower can be reduced, and the initial cost can be reduced. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a two-fluid nozzle of the present invention.

FIGS. 2A and 2B are drawings of a whirler used for the nozzle.

FIGS. 3A and 3B are views showing another whirler. FIG.

FIGS. 4A and 4B are views showing another whirler.

FIG. 5 is a diagram showing the results of a comparative experiment of the relationship between the air-water ratio and the particle diameter between the nozzle of the present invention and the nozzle of the conventional example.

FIG. 6 is a diagram showing the results of a comparative experiment of the relationship between the spray flow rate and the particle diameter between the nozzle of the present invention and the nozzle of the conventional example.

FIG. 7 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 8 is a cross-sectional view of a conventional nozzle.

FIG. 9 is a sectional view of another conventional nozzle.

[Explanation of symbols]

 Reference Signs List 20 Nozzle body 21 Base 22 Core 23 Chip 25 Flow path 27 Whirler 28 Orifice 29 Gas inflow chamber 30 Gas inflow hole 31 Gas inflow path 33 Gas-liquid mixing chamber 34 Step 35 Reduced diameter chamber 36 Injection port 38 Injection hole 40 Liquid supply pipe 41 Compressed air supply pipe

Continued on the front page F term (reference) 4F033 QA04 QB02Y QB03X QB12Y QB15X QD04 QD15 QD16 QE21 QF23

Claims (3)

[Claims] 1. A flow path is formed along an axis from a base end side of a nozzle body to a front end injection side, a liquid supply pipe is connected to an inlet of the flow path, and a whirler and an orifice are connected to the flow path. A gas inlet hole is provided at the circumferential wall of the flow path on the injection side from the arrangement position of these whirlers and orifices at intervals in the circumferential direction, and a gas annular flow path communicating with the outer ends of the gas inlet holes is provided. And, the gas annular flow path is communicated with a gas inflow passage formed in the nozzle body, and the liquid flowing along the axis is swirled by a stirrer and squeezed by an orifice. , A two-fluid nozzle configured to spray the mixed fluid from a tip injection port. 2. The gas turbine according to claim 1, wherein the whirler is arranged on the inflow side, the orifice is arranged on the injection port side with respect to the whirler, and the gas inflow hole is provided on the inner wall of the flow path on the outlet side of the orifice. 2. The two-fluid nozzle according to 1. 3. A reduced-diameter chamber having a gas-liquid mixing chamber having an enlarged diameter provided between a flow path from the position where the gas inlet hole is provided to a tip injection port, and a step provided at a front end side of the gas-liquid mixing chamber. 3. The two-fluid nozzle according to claim 1, wherein a conical injection port is provided at an end of the reduced diameter chamber, and a porous injection hole is provided in a nozzle head on an outer wall of the nozzle port. 4.