JP2005106411A - Pre-filmer type air blast granulating nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pre-filmer type air blast granulating nozzle for injecting liquid jet flow onto an inner circumferential surface of a liquid film forming body to be filmed, so that the liquid film is granulated by air currents, in which it can be favorably granulated in a wide liquid flow range. <P>SOLUTION: Liquid distributed to a liquid distribution passage 18 disposed in a granulating air current rotating blade 15a from a liquid manifold 17 passes an opening at a blade end of the granulating air current rotating blade 15a to reach a liquid film forming surface 12a of the liquid film forming body 12 to securely form the liquid film 13 without directly being exposed to rotary air currents even when liquid injection speed is low. The liquid film 13 is granulated by action of the rotary air currents, and it can be favorably granulated in a wide liquid flow range. As used for a fuel nozzle in a gas turbine combustor, generation of NOx and unburnt components can be restricted in a wide actuation range of an engine. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air blast atomizing nozzle that atomizes a liquid by an air current, and more particularly to a prefilmer type air blast atomizing nozzle that spreads a liquid as a liquid film on an annular liquid film forming surface and then atomizes by an air current. Furthermore, the present invention relates to a pre-filmer type air blast atomizing nozzle that atomizes liquid fuel by an air flow flowing into a combustor chamber in a continuous combustion apparatus such as a gas turbine combustor.

  In a gas turbine combustor, as a fuel nozzle for atomizing liquid fuel by an air flow flowing into a combustion chamber, a fuel liquid film is formed on the inner peripheral surface of a cylindrical liquid film forming body having a thin tip. A fuel nozzle that employs a method of forming and atomizing the liquid film in a free space downstream of the tip portion by an air flow flowing inside and outside the liquid film forming body has been put into practical use. This type of fuel nozzle was initially put into practical use as a fuel nozzle for gas turbines, but can also be used for atomization of liquids other than fuel, and gas such as steam can be used instead of air. . The fuel nozzle by this method is called a prefilmer type air blast atomizing nozzle because it breaks the liquid into fine particles by exposing the liquid to a thin liquid film and exposing it to an air stream.

FIG. 6 shows a typical form of a conventional prefilmer type air blast atomizing nozzle for a gas turbine. In this pre-filmer type air blast atomization nozzle 6 according to this prior art, the liquid passes through a plurality of outflow holes 19 from an annular liquid manifold 17 provided in the wall of the liquid film forming body 12, and then the liquid film forming body 12. The liquid flows out onto the liquid film forming surface 12b formed on the inner peripheral surface. In order to form a liquid film having a uniform thickness as much as possible in the circumferential direction, the outflow hole 19 is formed to be inclined with respect to the liquid film formation surface 12b so that the outflowing liquid swirls on the liquid film formation surface 12b. Has been. Instead of the plurality of outflow holes 19, a slit that opens over the entire circumference may be formed. The thing similar to the atomization nozzle shown in FIG. 6 is disclosed by patent document 1, for example.
US Pat. No. 3,912,164 (column 2, lines 22-57, FIG. 1)

  The method of forming the liquid manifold 17 having the shape of the annular chamber is divided into at least two parts so that the wall surface of the annular space becomes the surface, and after machining them, the entire circumference is welded or hot brazed. It can be integrated with each other or manufactured by precision casting. The former method is prone to defects such as liquid leakage from minute gaps due to incomplete joining and blockage of the flow path due to the flow of molten metal into the annular space, resulting in poor production costs. There is a problem that becomes high. On the other hand, precision casting is not suitable for low-volume production. In addition, when used as a fuel nozzle for an aircraft gas turbine, the fuel nozzle is exposed to high-temperature and high-pressure air to the combustor. And coking is likely to occur. In order to prevent the occurrence of such a phenomenon, the surface area (wetting area) of the portion where the fuel flow path is disposed is made as small as possible, and further, the surface and the fuel flow path are arranged to suppress heat inflow from the fuel nozzle surface. A so-called heat shield is provided to provide a heat insulating layer between them. However, since the liquid film forming body provided with the annular chamber is exposed to the high temperature air flow in addition to the outer peripheral surface, the amount of inflow heat is large, and the shape is not simple, so the heat shielding structure is complicated. . If an attempt is made to provide sufficient heat shielding, the wall of the annular part will inevitably become thick, so the optimum flow path shape cannot be employed to effectively bring the air flow into contact with the liquid film, or the outer dimensions of the fuel nozzle There is also a problem such as becoming larger.

In order to solve the problems in forming the annular liquid manifold in the wall of the liquid film forming body, a cylindrical liquid ejector is disposed on the central axis of the liquid atomizing nozzle, and its outer periphery A cylindrical liquid film forming body is coaxially disposed on the liquid jet, and liquid is ejected radially from a plurality of liquid injection holes opened in the side wall of the liquid ejector, and is collided with the inner peripheral surface of the liquid film forming body. A system (Non-patent Document 1) is proposed. FIG. 7 shows a typical form of a pre-filmer type air blast atomization nozzle as an atomization nozzle adopting this method. In the prefilmer type air blast atomization nozzle 7, the liquid fed into the liquid manifold 17 formed inside the liquid ejector 19 is ejected radially from the plurality of liquid ejection holes 23. The liquid jet collides with the liquid film forming surface 12b formed as the inner peripheral surface of the liquid film forming body 12, and spreads as a liquid film 13 thereon. A plurality of atomized airflow swirl vanes 15 a are disposed in the atomized airflow annular channel 16 a formed between the liquid film forming surface 12 b and the outer peripheral surface of the fuel injector 19. The swirling airflow generated by the atomized airflow swirling blades 15a has the role of splitting the liquid film 13 that has flowed out into the free space downstream from the tip 12a of the liquid film forming body 12, and the liquid film 13 along the liquid film forming surface 12b. It also has a role of extending to the tip 12a of the liquid film forming body 12. Unlike the pre-filmer type air blast fuel nozzle 6, the pre-filmer type air blast fuel nozzle 7 does not have an annular fuel manifold, so the main part can be manufactured only by machining, and as a result, the yield is high, so the manufacturing cost is high. Go down. Since the fuel injector is a cylinder with a small outer diameter, it is possible to prevent overheating of the fuel by simple heat shielding, the liquid film forming body can be a thin cylinder, and the maximum diameter of the entire fuel nozzle can be reduced. is there.
Proceedings of the 38th Aircraft and Space Propulsion Lecture and the 8th Ram / Scramjet Engine Symposium, January 1998, p151-155, Fig. 1 left A-type

  However, the prefilmer type air blast atomizing nozzle as shown in FIG. 7 has the following problems. When operating at a fuel flow rate much lower than the rated flow rate, the jet velocity is small, so that the fuel jet 24 is bent downstream by the atomized air flow as schematically shown in FIG. 8, and atomized in the liquid column state. Is done. This problem becomes prominent in the case of a large fuel fuel nozzle in which the radial distance between the injection hole 23 on the surface of the injector 19 and the liquid film forming surface 12b is large. Since the diameter of the fuel jet 24 is also increased, the swirling airflow generated by the atomized airflow swirl blade 15a becomes a cross airflow and the fuel is easily atomized, and the fuel jet reaches the liquid film formation surface in the form of a liquid column. It is difficult to let It is known that atomization by the cross stream of the liquid column is generally inferior to atomization of the liquid film by the parallel air flow at the same speed. When the ejection speed is even smaller, the jet is not vigorous, so the liquid flows downstream on the surface of the injector 19 as schematically shown in FIG. Become. The liquid mass 25 becomes coarse particles although it breaks up because the air velocity is not fast at the tip 19a. Further, when the liquid injection amount is constant, in order to increase the injection speed, the injection holes 23 must be reduced or the number of injection holes 23 must be reduced. However, if the injection holes 23 are reduced, clogging is likely to occur. If the number of the injection holes 23 is decreased, the circumferential distance between the jets increases, so that it is difficult to form a liquid film having a uniform thickness in the circumferential direction. When used in a gas turbine combustor, both fuel atomization degradation and fuel-air ratio bias increase NOx production.

  As described above, a cylindrical liquid ejector is disposed on the central axis of the liquid atomizing nozzle, and a cylindrical liquid film forming body is coaxially disposed on the outer side thereof, and is opened on the side wall of the liquid ejector. In a pre-filmer type air blast atomizing nozzle that sprays liquid radially from a plurality of liquid injection holes, collides with the inner peripheral surface of the liquid film forming body and spreads it into a film shape, and atomizes the liquid film by the action of air current However, there is a problem to be solved in order to realize a fine atomization over a wide liquid flow rate range by reliably forming a liquid film even when the liquid ejection speed is low.

  An object of the present invention is to make a liquid jet flow collide with the inner peripheral surface of a liquid film forming body to spread it into a film shape, and in a prefilmer type air blast atomization nozzle that atomizes the liquid film by an air flow, the liquid ejection speed is Even when it is small, a liquid film is reliably formed, and as a result, good atomization is possible over a wide liquid flow range, and when used as a fuel nozzle of a gas turbine combustor, NOx and NOx are spread over a wide operating range of the engine. It is an object of the present invention to provide a novel prefilmer type air blast atomization nozzle capable of suppressing the generation of unburned components.

  The present invention has been made to solve the above problems, and a prefilmer type air blast atomization nozzle according to the present invention has a plurality of atomized airflow swirl blades outside a cylindrical central body having a liquid manifold. A liquid supply cylinder disposed in the circumferential direction, and a cylindrical liquid film forming body in which one or more cross-sectional rings are disposed coaxially on the outer side of the liquid supply cylinder and the inner peripheral surface forms a liquid film formation surface. A liquid film forming section configured and a shroud disposed coaxially on the outermost periphery of the liquid film forming body, and a liquid distribution channel extending from the liquid manifold is disposed inside the atomized airflow swirl vane. A liquid film forming surface of the liquid film forming body from the opening of the liquid distribution flow path, the liquid splitting from the liquid manifold to the liquid distribution flow path opened at a blade tip of the atomized air flow swirl vane Liquid film flowing out Formed, consists being atomized by the action of the liquid film is given mainly turning by the atomization air flow swirl vanes airflow.

  In the prefilmer type air blast atomization nozzle according to the present invention, a liquid distribution flow path extending from the liquid manifold and opening at the blade end of the atomization air flow swirl vane is disposed inside the atomization air flow swirl vane. The liquid is branched from the liquid manifold to the liquid distribution channel, and flows out from the opening at the blade tip of the atomized airflow swirl vane onto the liquid film forming surface of the liquid film forming body to form a liquid film. Therefore, since the liquid reaches the liquid film forming surface without being directly exposed to the atomized airflow in the state of the liquid column, the liquid film is reliably formed on the liquid film forming surface even when the liquid flow rate is small. Good atomization is possible over a wide liquid flow rate range. If this prefilmer type air blast atomization nozzle is used as a fuel nozzle of a gas turbine combustor, the generation of NOx and unburned components can be suppressed over a wide operating range of the engine.

  In the prefilmer type air blast atomization nozzle according to the present invention, the nozzle is formed between the inner peripheral surface of the shroud and the outer peripheral surface of the outermost peripheral liquid film forming body located at the outermost peripheral portion of the liquid film forming portion. A plurality of shroud airflow swirl vanes can be disposed in the shroud annular channel at a position upstream from the tip of the outermost peripheral liquid film forming body. In this way, not only can the mixing of the atomized particles and the air flowing through the shroud annular channel be significantly promoted, but there is also an advantage that the spread of the spray in the radial direction can be adjusted by the blade angle of the shroud airflow swirl blade. If the blade angle is decreased, a spray flow having a small spread can be formed, and if the blade angle is increased, a spray flow having a large spread can be obtained.

  In the prefilmer-type air blast atomization nozzle, the liquid manifold is composed of two or more sub-manifolds independent from each other, and the liquid distribution channels disposed inside the atomized airflow swirl vanes are divided into groups. Each group is connected to the sub-manifold, and the sub-manifold can be connected to a pipe provided with a valve for blocking or adjusting the flow rate of the liquid flowing into the sub-manifold. In this way, it is possible to adjust the distribution in the circumferential direction or the radial direction of the fuel. In a gas turbine combustor, NOx is likely to be generated during high-power operation, so it is necessary to mix the fuel with air as uniformly as possible. On the other hand, the fuel-air ratio is lower than that during high-power operation under low-power conditions or during startup. Because the fuel is too diluted to ignite because the air temperature is low and the air temperature is low, the flame is unstable and the combustion tends to be incomplete. It is preferable to make it unevenly distributed. In the above-described form of the pre-filmer type air blast atomizing nozzle according to the present invention, it is possible to unevenly distribute the fuel in the circumferential direction or the radial direction, so that the engine can be started reliably and the entire operation range can be combusted. There is an advantage that the exhaust performance can be improved together. The number of liquid distribution channel groups can be the same as the number of sub-manifolds. In this case, each sub-manifold can correspond to a different group of liquid distribution channels.

  The prefilmer type air blast atomization nozzle of the present invention includes a liquid supply cylinder in which a plurality of atomized airflow swirl vanes are arranged in the circumferential direction outside a cylindrical central body having a liquid manifold, and the liquid supply cylinder A liquid film forming section formed of a cylindrical liquid film forming body having an annular shape with one or more cross-sections disposed coaxially on the outer side and having an inner peripheral surface forming a liquid film forming surface; And a liquid distribution channel extending from the liquid manifold is disposed inside the atomized airflow swirl vane and opens at a blade end of the atomized airflow swirl vane. Therefore, the liquid is diverted from the liquid manifold to the liquid distribution channel, and flows out from the opening at the blade tip of the atomizing airflow swirl vane onto the liquid film forming surface of the liquid film forming body to form a liquid film. Therefore, since the liquid reaches the liquid film forming surface without being directly exposed to the atomized airflow, the liquid film is reliably formed even when the liquid ejection speed is low. Since the liquid film is atomized mainly by the action of the airflow swirled by the atomized airflow swirl blade, good atomization can be achieved over a wide liquid flow rate range. If used as a fuel nozzle of a gas turbine combustor, the generation of NOx and unburned components can be suppressed over a wide operating range of the engine.

  The prefilmer type air blast atomizing nozzle according to the present invention is a shroud formed between the inner peripheral surface of the shroud and the outer peripheral surface of the outermost peripheral liquid film forming body located on the outermost peripheral surface of the liquid film forming portion. A plurality of shroud airflow swirl vanes can be disposed in the annular channel at a position upstream from the tip of the outermost peripheral liquid film forming body. In this way, not only can the mixing of the atomized particles and the air flowing through the shroud annular channel be significantly promoted, but the radial spread of the spray can be adjusted by changing the blade angle of the shroud airflow swirl blade. There is. If the blade angle is decreased, a spray flow having a small spread can be formed, and if the blade angle is increased, a spray flow having a large spread can be obtained.

  In the prefilmer-type air blast atomization nozzle, the liquid manifold is composed of two or more sub-manifolds independent from each other, and the liquid distribution channels disposed inside the atomized airflow swirl vanes are divided into groups. Each group is connected to the sub-manifold, and a pipe provided with a valve for blocking or adjusting the flow rate of the liquid flowing into the sub-manifold can be connected to the sub-manifold. In this way, it is possible to adjust the distribution in the circumferential direction or the radial direction of the fuel by manipulating the opening degree of the valve disposed in the pipe. In a gas turbine combustor, NOx is likely to be generated during high-power operation, so it is necessary to mix the fuel with air as uniformly as possible. Because it is small compared to the time and the temperature of the air is low, if the fuel is mixed evenly, the fuel is too dilute and cannot be ignited, or the flame is unstable and combustion tends to be incomplete, so the fuel is spatially separated. It is preferable to make it unevenly distributed. In the above-described form according to the present invention, the fuel can be unevenly distributed in the circumferential direction or the radial direction, so that the engine can be reliably started and the combustion and exhaust performance can be improved over the entire operation range. There is an advantage that you can.

  FIG. 1 is a longitudinal sectional view showing a first embodiment of a prefilmer type air blast atomizing nozzle (hereinafter simply referred to as “atomizing nozzle” in the description of the embodiments) according to the present invention. In addition, the atomized airflow swirl blade (hereinafter simply referred to as “swirl blade” in the description of the embodiment) used in the atomization nozzle shown in each longitudinal view including FIG. 1 is simply expressed. It is displayed using. In the atomization nozzle 1 shown in FIG. 1, the same code | symbol is attached | subjected to the component and site | part which show | play the function equivalent to the conventional atomization nozzles 6 and 7 shown in FIG.6 and FIG.7. The atomizing nozzle 1 includes a liquid supply cylinder 10 in which a plurality of swirl blades 15 a are disposed around a central body 10 a, and a liquid film forming surface 12 b formed on the inner peripheral side of the rotating body surface and is coaxial with the liquid supply cylinder 10. The liquid film forming part 11 is composed of a single liquid film forming body 12 having an annular cross section disposed on the outer periphery, and the shroud 14 having an annular cross section disposed coaxially on the outer periphery of the liquid film forming body 12. .

  Inside the swirl vane 15a, there is disposed a liquid distribution channel 18 that communicates the opening 10c that opens to the outer end face of the swirl vane 15a and the liquid manifold 17 disposed inside the central body 10a of the liquid supply cylinder 10. ing. The liquid from the liquid manifold 17 flows through the liquid distribution flow path 18 and then flows out from the opening 10c onto the liquid film forming surface 12b of the liquid film forming body 12 to form the liquid film 13 on the liquid film forming surface 12b. . The liquid film 13 is atomized mainly by the swirling airflow generated by the swirling blades 15a. The shroud airflow flowing through the annular flow path 16 b formed outside the liquid film forming body 12 and inside the shroud 14 causes the liquid film 13 to be on the outer peripheral surface of the liquid film forming body 12 at the tip 12 a of the liquid film forming body 12. It has the effect of suppressing wraparound and prevents the generation of coarse particles.

  In this embodiment, when the blades of the annular flow path 16b are not swirl blades, the shroud airflow is not swirled, so that the spread of spray is suppressed. When the swirl vanes for shroud airflow in the same direction as the swirl vanes 15a are disposed in the annular passage 16b and the mounting angle is increased, the shroud airflow swirl becomes stronger and the spread of the spray in the radial direction is promoted. Conversely, if a swirl vane for shroud airflow in the opposite direction to the swirl vane 15a is provided and its mounting angle is increased, mixing of the airflow with the shroud airflow and the airflow by the swirl vane 15a is promoted. The spread of the spray in the radial direction is suppressed. When used as a fuel nozzle for a gas turbine combustor, it is indispensable for the stability of the flame to form a recirculation region of burned gas on the central axis, so swirl vanes are arranged inside and outside the mounting angle of 50 °. . In FIG. 1, the liquid film forming surface 12 b is depicted as a right cylindrical surface, but may be a tapered surface that smoothly expands toward the downstream side. For simplification of the drawing, the line connecting the upper and lower edges of the front end side is omitted.

  FIG. 2 is a longitudinal sectional view showing a second embodiment of the atomizing nozzle according to the present invention. In the atomization nozzle 2 shown in FIG. 2, the same components as those having the same functions as those of the atomization nozzle 1 shown in FIG. In the atomizing nozzle 2, two liquid film forming bodies 12c and 12d are arranged coaxially with the fuel supply cylinder 10 as a liquid film forming section, and correspondingly, a liquid film is formed from the liquid manifold 17 into the swirl vane 15a. It differs from the atomization nozzle 1 in that liquid distribution channels 18a and 18b for supplying liquid to the formed bodies 12c and 12d are provided. The liquid film forming body 12d is supported by inserting the annular upstream end thereof into the notch of the rear edge of the swirl blade 15a.

  The atomizing nozzle 2 includes two liquid film forming bodies 12c and 12d, and the peripheral length of the tip portion thereof is longer than that of the atomizing nozzle 1 employing the single liquid film forming body 12, so that the liquid If the flow rate is the same, the liquid film becomes thin and the atomization performance is improved. These two liquid film forming bodies 12c and 12d are also effective when it is necessary to make the dispersion in the radial direction of the liquid particles uniform with a short axial distance. The distribution of the liquid to the liquid film forming bodies 12c and 12d can be adjusted by the channel resistance of the liquid distribution channels 18a and 18b.

  FIG. 3 is a longitudinal sectional view showing a third embodiment of the atomizing nozzle according to the present invention. In the atomization nozzle 3 shown in FIG. 3, the same reference numerals are given to the main components and parts having the same functions as those of the atomization nozzles 1 and 2 shown in FIG. 1 and FIG. Description is omitted. The atomization nozzle 3 includes two independent sub-manifolds 17a and 17b arranged as a liquid manifold. Although not shown in FIG. 3, a pipe provided with a valve for shutting off or adjusting the flow rate of the liquid flowing into the sub-manifolds 17 a and 17 b is connected upstream of them. The difference from the atomization nozzle 2 shown in FIG. 2 is that the flow distribution to the liquid film forming bodies 12c and 12d can be changed by providing the independent sub-manifolds 17a and 17b. When the atomizing nozzle 3 is used as a fuel nozzle of a gas turbine, a radial distribution of fuel suitable for different operating conditions of the engine can be realized, and high combustion efficiency and NOx emission reduction can be achieved in a wide operating range. That is, the fuel is supplied only to the liquid film forming body 12d when the fuel flow is low and the output is low, and the fuel is supplied also to the liquid film forming body 12c when the output is high. Enables optimization.

  FIG. 4 is a view showing a fourth embodiment of the atomizing nozzle according to the present invention, wherein (a) is a longitudinal sectional view, (b) is an AOA transverse section, and (c) is a BO'B transverse section. In FIG. 4, the same components as those of the atomizing nozzles 1, 2, and 3 having the same functions as those of the atomizing nozzles 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted. The atomization nozzle 4 shown in FIG. 4 and the atomization nozzle 1 shown as the first embodiment in FIG. 1 both have a common feature that only one liquid film forming body is provided. The difference is that two manifolds are provided and the atomized airflow swirl blades are grouped into two correspondingly. The flow distribution vanes are numbered consecutively in the circumferential direction, and the liquid distribution passages arranged in the even numbered swirl vanes gather in the sub-manifold 17a and are arranged in the odd numbered swirl vanes. The provided liquid distribution flow paths are gathered in the sub-manifold 17b, and the flow distribution of these two systems is adjusted by valves 21a and 21b provided in the pipes 20a and 20b connected to the sub-manifolds 17a and 17b, respectively. Thus, the fuel distribution in the circumferential direction can be changed.

  FIG. 5 is a longitudinal sectional view showing a fifth embodiment of the atomizing nozzle according to the present invention. In FIG. 5, the same components as those of the atomizing nozzles 1, 2, 3, 4 having the same functions and portions are denoted by the same reference numerals, and the description thereof is omitted. The difference between the atomizing nozzle 5 shown in FIG. 5 and the atomizing nozzle 4 shown as the fourth embodiment in FIG. 4 is that the atomizing nozzle 5 is added to the atomizing nozzle 4 by adding one sub-manifold 17c. Thus, the number of the liquid film forming bodies 12b is two. In the atomization nozzle 5, it is possible to adjust the dispersion of the liquid not only in the circumferential direction but also in the radial direction.

It is a longitudinal cross-sectional view which shows 1st Example of the pre filmer type air blast atomization nozzle by this invention. It is a longitudinal cross-sectional view which shows 2nd Example of the pre filmer type air blast atomization nozzle by this invention. It is a longitudinal cross-sectional view which shows 3rd Example of the pre filmer type air blast atomization nozzle by this invention. It is the longitudinal cross-sectional view which shows 4th Example of the prefilmer type air blast atomization nozzle by this invention, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view, (c) is a cross-sectional view in a conical surface It is. It is a longitudinal cross-sectional view which shows 5th Example of the pre filmer type air blast atomization nozzle by this invention. It is sectional drawing which shows the example of the typical form of the conventional prefilmer type air blast atomization nozzle. It is a longitudinal cross-sectional view which shows an example of another form of the conventional prefilmer type air blast atomization nozzle. It is a schematic diagram which shows the problem which arises when the ejection speed of the conventional prefilmer type air blast atomization nozzle shown in FIG. 7 is low. It is a schematic diagram which shows the problem which arises when the jetting speed of the conventional prefilmer type air blast atomization nozzle shown in FIG. 7 is still smaller.

Explanation of symbols

1, 2, 3, 4, 5 Prefilmer type air blast atomization nozzle 10 Liquid supply cylinder 10a Central body 10c Opening 11 Liquid film forming part 11a Liquid film forming body 11b Liquid film forming body 12, 12c, 12d Liquid film forming body 12a Liquid film forming body tip 12b Liquid film forming surface 13 Liquid film 14 Shroud 15a Atomizing airflow swirl vane 15b Swirl airflow swirl vane 16a Atomizing airflow annular channel 16b Shroud annular channel 17 Liquid manifold 17a Submanifold 17b Submanifold 17c Sub-manifold 18 Liquid distribution flow path 18a Liquid distribution flow path 18b Liquid distribution flow path 18c Liquid distribution flow path 19 Liquid ejector
20a, 20b Piping 21a, 21b Valve

Claims (3)

  A liquid supply cylinder in which a plurality of atomized airflow swirl vanes are arranged in the circumferential direction outside a cylindrical central body having a liquid manifold, and one or more cross sections arranged coaxially on the outside of the liquid supply cylinder It is composed of a liquid film forming portion formed of a cylindrical liquid film forming body having an annular inner peripheral surface forming a liquid film forming surface, and a shroud disposed coaxially on the outermost periphery of the liquid film forming body. A liquid distribution channel extending from the liquid manifold is disposed inside the atomized airflow swirl vane and is open at a blade end of the atomized airflow swirl vane, and diverts from the liquid manifold to the liquid distribution channel. The flowed liquid flows out from the opening of the liquid distribution channel onto the liquid film forming surface of the liquid film forming body to form a liquid film, and the liquid film is swirled mainly by the atomized airflow swirl blades Because it is atomized by the action of Prefilmers type air blast atomizing nozzle that.   A tip portion of the outermost peripheral liquid film forming body is formed in a shroud annular channel formed between an inner peripheral surface of the shroud and an outer peripheral surface of the outermost peripheral liquid film forming body located on the outermost outer periphery of the liquid film forming section. The pre-filmer type air blast atomizing nozzle according to claim 1, wherein a plurality of shroud airflow swirl vanes are disposed at a further upstream position.   The liquid manifold is composed of two or more sub-manifolds independent from each other, and the liquid distribution passages arranged inside the atomized airflow swirl vanes are divided into groups, and the sub-manifolds are divided into groups. The pre-filmer type air blast atomization according to claim 1 or 2, wherein the sub-manifold is connected to a pipe provided with a valve for blocking or adjusting a flow rate of the liquid flowing into the sub-manifold. nozzle.

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