JP2021041370A - spray nozzle - Google Patents

Abstract

To provide a spray nozzle capable of improving atomization performance of liquid which is injected to an anisotropically shaped area.SOLUTION: By combining an ellipse-shaped discharge port 1, a first tapered flow passage 2 slantingly extending in a direction in which a major axis length of an elliptic shape of the discharge port decreases and converging to a circular shape, a first cylindrical flow passage 3 continuing to the first tapered flow passage, a second tapered flow passage 4 slantingly extending from the first cylindrical flow passage in a direction in which a flow passage diameter increases, a second cylindrical flow passage 5 continuing to the second tapered flow passage, a disk-shaped partition wall part 6 disposed crossing a flow passage on the upstream side of the second cylindrical flow passage and having a plurality of liquid introduction holes 6a, and a third cylindrical flow passage 7 extending to the upstream side of the disk-shaped partition wall part, forming the plurality of liquid introduction holes at intervals on a concentric circle of the nozzle axis and making the liquid introduction holes penetrate in the axial direction of a nozzle while being inclined at the same orientation in the circumferential direction of the concentric circle, a spray nozzle 10 capable of injecting liquid in a hollow-cone-shaped pattern with a cross section of an elliptic shape is manufactured.SELECTED DRAWING: Figure 1

Description

The present invention relates to a spray nozzle for spraying or spraying a liquid in a hollow elliptical cone-like pattern having an elliptical cross section.

Spray nozzles are used for spraying fossil fuels in boilers, gas turbines, engines, etc. for power generation. In these spray nozzles, atomization performance is required in order to improve combustion efficiency. As the spray shape, for example, in spraying the fuel mixing chamber of a gas turbine, a spray shape having a hollow cone-like pattern, which is advantageous for atomization performance, is used.

For example, Japanese Patent No. 5679326 (Patent Document 1) states that, in a gas turbine combustion apparatus, fuel is hollow as a fuel supply means for supplying fuel to a combustion cylinder that burns a mixture of fuel and air. A hollow cone pattern pressure injection nozzle that highly atomizes liquid fuel by injecting it in a conical shape is disclosed.

On the other hand, there are cases where a flatter and elliptical fuel spray pattern is required due to restrictions on the inside of the engine and the combustor.

Japanese Patent No. 5681420 (Patent Document 2) discloses a fuel injection valve provided with a fuel nozzle cylinder portion capable of forming a flat fuel injection foam extending in the axial direction of the valve shaft of the throttle valve in an engine fuel injection device. Has been done.

According to Japanese Patent No. 5417258 (Patent Document 3), in a combustion device for burning fossil fuel, the diffusion shape of the spray particles of the reducing agent sprayed into the furnace at the tip thereof is expanded in the horizontal direction with respect to the wall surface of the furnace. A plurality of spray holes for spraying are provided so that a flat fan shape can be formed, and the plurality of spray holes are configured so that the flat fan-shaped spread angles, which are the diffusion shapes of the spray particles to be sprayed, are different from each other. The nozzle is disclosed.

Japanese Patent No. 5679326 (Claims, paragraph [0024]) Japanese Patent No. 5681420 (Claim 5) Japanese Patent No. 5417258 (Claim 2)

In the spray nozzle of Patent Document 1, since the cross-sectional shape of the holo cone, which is the injection pattern, is circular, it is not possible to spray into an irregularly shaped region such as a flat shape, and the use is restricted, while Patent Document 2 In the spray nozzles of No. 3 and No. 3, since the injection pattern having a flat cross section was a full cone, it was difficult to atomize the sprayed liquid.

An object of the present invention is to provide a spray nozzle capable of improving the atomization performance of a liquid to be sprayed on an anisotropically shaped region.

As a result of diligent studies to achieve the above problems, the present inventors cannot improve the atomization performance in an irregular shape pattern such as a flat shape with a conventional spray nozzle, so that the injection pattern is a hollow cone having an elliptical cross section. By producing a spray nozzle having a hollow conical pattern whose cross-sectional shape is elliptical in the direction of the axis of the nozzle, we succeeded in improving the atomization performance with a pattern having an irregular cross-section. However, although it succeeded in atomizing to some extent, unlike the isotropic circular cross-section, the elliptical cross-section, which is an amorphous shape, sprays an ellipse when the spray pressure is adjusted in order to adjust the spray amount. The shape of the pattern changed, which adversely affected the combustion efficiency, such as when spraying fossil fuels in the combustor of a gas turbine. Therefore, as a result of further diligent studies, the present inventors have devised a nozzle structure so that the elliptical spray pattern does not change with respect to a wide range of injection pressures even for a holocorn having an elliptical cross section. We succeeded in atomizing.

That is, the spray nozzle of the present invention is a spray nozzle for injecting a liquid in a hollow cone-shaped pattern having an elliptical cross section, and the elliptical discharge port and the elliptical major axis length are reduced from this discharge port. A first tapered flow path extending in a direction and converging in a circular shape, a first cylindrical flow path connected to the first tapered flow path, and a flow path diameter (flow path diameter (from this first cylindrical flow path) from the first cylindrical flow path. A second tapered flow path extending in an inclined direction in which the circular diameter) increases, a second cylindrical flow path connected to the second tapered flow path, and an upstream of the second cylindrical flow path. A disk-shaped partition wall that is arranged on the side across the flow path (or along the nozzle axis in the thickness direction) and has a plurality of liquid introduction holes, and extends to the upstream side of the disk-shaped partition wall portion. A third cylindrical flow path is provided, and the plurality of liquid introduction holes are formed at intervals on concentric circles of the nozzle axis, and are inclined in the same direction in the circumferential direction of the concentric circles of the nozzle. It extends in the direction of the heart. The disc-shaped partition wall portion may have 3 to 10 liquid introduction holes. The liquid introduction hole may be inclined at 10 to 60 ° with respect to the axial direction of the nozzle. The liquid introduction holes (particularly, the center thereof) may be formed at equal intervals at positions corresponding to the outer periphery of the first cylindrical flow path. In the elliptical discharge port, the major axis may be 1.2 times or more the minor axis. The area of the flow path port of the first cylindrical flow path may be 2 to 5 times the total area of the introduction port of the liquid introduction hole. In the first tapered flow path, the taper angle of the vertical cross-sectional shape on the short axis of the discharge port is 30 ° or less, and the taper angle of the vertical cross-sectional shape on the long axis of the discharge port is 30 to 90 °. May be good. Further, in the first tapered flow path, the vertical cross-sectional shape on the long axis of the discharge port is a curved portion that curves and expands from the downstream end of the first cylindrical flow path toward the downstream direction, and this curved portion. It may have a shape consisting of a straight portion that expands linearly from to the downstream direction to reach the discharge port. The total flow path length of the first tapered flow path and the first cylindrical flow path may be 0.2 to 2 times the flow path diameter of the first cylindrical flow path.

In the present invention, an elliptical discharge port, a first tapered flow path extending from the discharge port in a direction in which the major axis length of the elliptical shape decreases, and converging into a circular shape, and the first tapered flow path. A first cylindrical flow path connected to the tapered flow path of the above, a second tapered flow path extending from the first cylindrical flow path in a direction in which the flow path diameter increases, and the second taper. A second cylindrical flow path connected to the shaped flow path, and a disk-shaped partition wall portion arranged across the flow path on the upstream side of the second cylindrical flow path and having a plurality of liquid introduction holes. , A third cylindrical flow path extending to the upstream side of the disk-shaped partition wall is combined, and the liquid introduction holes are formed at intervals on the concentric circles of the nozzle axis, and the circumferential direction of the concentric circles. By inclining in the same direction and penetrating in the axial direction of the nozzle, it is possible to provide a spray nozzle capable of injecting a liquid in a hollow cone-shaped pattern having an elliptical cross section. Amplification performance can be improved. Further, by forming 3 to 10 liquid introduction holes in the disc-shaped partition wall portion, the elliptical holocorn spray shape can be maintained for a wide range of injection pressures even if the holocorn has an elliptical cross section.

FIG. 1 is a schematic partial perspective perspective view showing an example of the spray nozzle of the present invention. FIG. 2 is a front view of the spray nozzle of FIG. 1 and a view showing a spray pattern. FIG. 3 is a schematic cross-sectional view taken along the line I-I of FIG. FIG. 4 is a schematic cross-sectional view taken along line II-II of FIG. FIG. 5 is a partially enlarged view of FIG. FIG. 6 is a schematic front view of the disk-shaped partition wall portion of FIG. FIG. 7 is a partially cutaway perspective view for showing the flow path shape of the liquid introduction hole of the disk-shaped partition wall portion of FIG. FIG. 8 is a schematic perspective view showing a usage state of the spray nozzle of FIG. FIG. 9 is a graph showing the distribution state of the water density in the spray nozzle obtained in Example 1.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings as necessary.

FIG. 1 is a schematic partial perspective perspective view showing an example of the spray nozzle of the present invention, FIG. 2 is a front view and a spray pattern of the spray nozzle of FIG. 1, and FIG. 3 is a schematic cross section of line II of FIG. FIG. 4 is a schematic cross-sectional view taken along line II-II of FIG. 2, FIG. 5 is a partially enlarged view of FIG. 4, and FIG. 6 is a schematic front view of the disk-shaped partition wall portion of FIG. FIG. 7 is a partially cutaway perspective view for showing the flow path shape of the liquid introduction hole of the disk-shaped partition wall portion of FIG.

The spray nozzle 10 has a flow path extending along the axis inside the nozzle, and discharges or ejects a liquid passing through this flow path in a hollow cone pattern (hollow elliptical cone shape) having an elliptical cross section (hollow cone shape). Can be sprayed). Specifically, this flow path extends from the elliptical discharge port 1 located on the most downstream side in a direction in which the major axis length of the elliptical shape decreases, and converges in a circular shape. The flow path diameter (circular diameter) increases from the first tapered flow path 2, the first cylindrical flow path 3 connected to the first tapered flow path 2, and the first cylindrical flow path 3. A second tapered flow path 4 extending in an inclined direction, a second cylindrical flow path 5 connected to the second tapered flow path 4, and a second cylindrical flow path 5 connected to and connected to the second cylindrical flow path 5. It is formed by a plurality of liquid introduction holes 6a formed in the disk-shaped partition wall portion 6 and a third cylindrical flow path 7 connected to the disk-shaped partition wall portion 6. In the spray nozzle 10, the liquid flows in from the third cylindrical flow path 7 on the upstream side, passes through the liquid introduction hole 6a and the flow path following the liquid introduction hole 6a, and passes through the discharge port 1 as shown in FIG. A liquid stream having a hollow cone pattern having an elliptical cross section is discharged from the nozzle.

The third cylindrical flow path 7 is a flow path having a circular cross section (round shape or substantially perfect circle shape) perpendicular to the center of the nozzle axis, and has a volume and a volume for stably passing the liquid. It is formed in a hollow cylindrical shape having a length.

In this spray nozzle 10, the liquid introduced into the third cylindrical flow path 7 in order to form a holocorn pattern having an elliptical cross section passes through the third cylindrical flow path 7, and then is a third. The flow state is changed (turbulent) by the disk-shaped partition wall portion (core) 6 arranged on the downstream side of the cylindrical flow path 7.

Specifically, the liquid that has passed through the third cylindrical flow path 7 is focused on the outer peripheral side of the flow path by passing through the liquid introduction hole 6a, and changes into a swirling flow due to the inclination of the liquid introduction hole 6a.

In the spray nozzle 10, as shown in FIGS. 6 and 7, the liquid introduction hole 6a has a circular opening shape and is inclined in the circumferential direction (or tangential direction) of the concentric circle with respect to the axial direction of the nozzle. It has a flow path (a flow path that inclines in the circumferential direction from upstream to downstream), and is spaced at a position (on a circle) whose center corresponds to the outer circumference of the first cylindrical flow path 3. , 5 pieces are formed at equal intervals. As shown in FIG. 7, each of the liquid introduction holes 6a has the _{same direction with respect to the nozzle axis direction at an inclination angle θ 1} (the passing liquid is directed from upstream to downstream) in order to generate a swirling flow. It is tilted in the direction in which it can turn in the right spiral direction). In this example, the tilt angle θ ₁ is about 25 °. In FIG. 6, the liquid introduction hole shown by the broken line indicates the liquid introduction hole on the back surface (upstream side).

The second cylindrical flow path 5 is a flow path having a circular cross section (round shape or substantially perfect circle shape) perpendicular to the nozzle axis, and is smaller than the third cylindrical flow path 7. By having a path diameter and providing a step between the third cylindrical flow path 7 and the third cylindrical flow path 7, the disk-shaped partition wall portion 6 can be fixed in the flow path by a simple method.

The second tapered flow path 4 is formed by the disc-shaped partition wall portion 6 to improve the injection pressure of the liquid passing while swirling the wall surface of the flow path, and has a taper angle of about 90 ° (nozzle shaft). It is formed at about 45 ° to the heart. The liquid focused by the second tapered flow path 4 is sent to the first cylindrical flow path (circular orifice) 3 in a state where the pressure is increased.

The first cylindrical flow path 3 is a flow path having a circular shape (round shape or substantially perfect circle shape) in a cross section perpendicular to the nozzle axis, and the flow path diameter (cross section perpendicular to the nozzle axis). The diameter of the second cylindrical flow path 5 is about 60% of the flow path diameter of the second cylindrical flow path 5. The area of the flow path port of the first cylindrical flow path 3 (the area of the cross section perpendicular to the nozzle axis) is about three times the total area of the introduction port of the liquid introduction hole 6a.

The first tapered flow path 2 is a flow path having a wall surface extending from the downstream end of the first cylindrical flow path 3, and swirls the wall surface of the first cylindrical flow path 3. It is formed to change the flowing liquid so that it flows in an elliptical cross section.

The first tapered flow path 2 is inclined so that the shape of the discharge port 1 on the downstream side is elliptical, and has a vertical cross-sectional shape (flow direction or axial direction) on the long axis of the elliptical discharge port 1. (Cross-sectional shape) is a curve that curves and expands from the downstream end of the first cylindrical flow path 3 toward the downstream direction, as shown in the partially enlarged view of the first tapered flow path 2 in FIG. The shape is composed of a portion (curved enlarged portion) 2a and a straight portion (linear enlarged portion) 2b that expands linearly from the downstream end of the curved portion toward the downstream direction to reach the discharge port. The vertical cross-sectional shape on the short axis is a straight line shape that gently inclines in the direction away from the axis from the upstream to the downstream (downstream direction). _{Further, in the first tapered flow path 2, the taper angle (θ 4a} × 2 in FIG. 5) of the vertical cross-sectional shape on the long axis of the discharge port 1 is about 55 °, whereas the vertical cross section on the short axis is about 55 °. The taper angle of the shape is about 1 °.

The radius of curvature of the curved portion 2a is about 2.3 mm, and in a virtual circle having this radius of curvature, the angle (central angle) θ ₅ of the fan shape (partial circle) having the curved portion as an arc is about 35 °. is there.

The total flow path length (the shortest distance from the discharge port 1 to the upstream end of the first cylindrical flow path 3) of the first tapered flow path 2 and the first cylindrical flow path 3 is the first cylindrical shape. It is 0.8 times the flow path diameter of the flow path 3.

The shape of the discharge port 1 is an elliptical shape in which the major axis is about 1.5 times the minor axis. As described above, in this nozzle, the discharge port 1 is formed into an elliptical shape to inject from the discharge port 1. The flow of liquid in a hollow cone-like pattern can be controlled in the shape of a hollow elliptical cone.

The outer shape of the spray nozzle 10 is substantially cylindrical, and a flange portion 8 extending in the radial direction is formed on the outer surface of the upstream end portion of the cylinder. Reference surfaces 8a and 8b facing each other in the minor axis direction of the discharge port 1 are formed on the flange portion 8, and the injection position of the hollow cone-shaped pattern can be easily determined by using the reference surfaces 8a and 8b as marks.

FIG. 8 is a schematic perspective view showing a usage state of the spray nozzle 10, wherein the liquid is sprayed from the spray nozzle 10 into the spray nozzle 10 in a hollow cone-shaped pattern 11 having an elliptical cross section. The shape of the hollow cone-shaped pattern can be adjusted by adjusting the angle of the spray nozzle 10 with respect to the object 12. Further, as described above, since the liquid that has passed through the disc-shaped partition wall portion 6 swirls, as shown in FIG. 2, the major axis of the elliptical spray pattern 9 in the liquid ejected from the discharge port 1 is the discharge port. It is sprayed in a shape that intersects the major axis of 1 by about 18 °. In FIG. 2, the spray pattern 9 shows only the extension shape.

In the spray nozzle of the present invention, the cylindrical flow path means a flow path having the same circular shape (round shape or substantially perfect circle shape) having the same cross section perpendicular to the nozzle axis. The flow path diameter of the third cylindrical flow path (diameter of the cross section perpendicular to the nozzle axis direction) may be the same as or smaller than the flow path diameter of the second cylindrical flow path. It is preferably large because the disk-shaped partition wall can be easily fixed and the liquid can be easily swirled. The flow path diameter of the third cylindrical flow path is, for example, 1.01 to 1.2 times, preferably 1.05 to 1.15 times, more preferably 1.01 to 1.15 times the flow path diameter of the second cylindrical flow path. It is 1.08 to 1.12 times. If the flow path diameter of the third cylindrical flow path is too large, it may be difficult to adjust the injection pressure of the liquid.

The number of liquid introduction holes formed in the disc-shaped partition wall portion (core) is not limited to 5, and it is sufficient that the passing liquid can be swirled, but a plurality of them is preferable, for example, 3 to 10 holes, preferably 4. ~ 8, more preferably 5-7. If the number of liquid introduction holes is too small, it may be difficult to inject in a hollow cone-like pattern, and conversely, if the number is too large, it may be difficult to generate a swirling flow.

The opening shape of the liquid introduction hole is not limited to a circular shape (perfect circular shape or substantially perfect circular shape), and may be an elliptical shape, a polygonal shape (hexagonal shape, etc.), or the like. When the opening shape of the liquid introduction hole is an irregular shape such as a rectangular shape or an elliptical shape, the long axis may be formed so as to be parallel to the tangent line on the concentric circle of the nozzle axis.

The position where the liquid introduction hole is formed is not limited to the position corresponding to the outer circumference of the first cylindrical flow path, but is formed at intervals on the concentric circles of the nozzle axis, and the liquid flow is formed in the second cylindrical shape. It suffices if it can be focused on the wall surface of the flow path, and it is preferable that it is formed at a position corresponding to the outer circumference of the first cylindrical flow path because it is possible to inject a hollow cone having an elliptical cross section with high atomization performance. It is particularly preferable that the center of the first cylindrical flow path is formed at a position corresponding to the outer circumference of the first cylindrical flow path. Further, the plurality of liquid introduction holes may include liquid introduction holes formed at positions slightly deviating from the concentric circles as long as the holo cone having an elliptical cross section can be injected.

The intervals between the plurality of liquid introduction holes may be different, but equal intervals are preferable because they can be uniformly atomized over a wide range of injection pressures.

The direction in which the plurality of liquid introduction holes are inclined may be the circumferential direction in the concentric circles of the nozzle axes. In the present specification and claims, the "circumferential direction" as the inclination direction of the liquid introduction hole means, strictly speaking, a substantially tangential direction at each liquid introduction hole in the concentric circles. Further, this substantially tangential direction means that the direction may intersect the tangential direction at a predetermined angle as long as the liquid can be injected in a hollow cone-like pattern. The crossing angle at which the liquid can be ejected in a hollow cone pattern is, for example, ± 20 ° or less, preferably ± 10 ° or less, and more preferably ± 5 ° or less.

Further, the inclination directions of the plurality of liquid introduction holes need to be unified in the same direction (the same direction when viewed from the center of the nozzle axis) so that the passing liquid can be swirled in the same direction, and the passing liquid is upstream. It is not limited to the direction in which it can turn in the right spiral direction (right-handed direction or Z-wound direction) from the downstream side, and may be a direction in which it can turn in the left spiral direction (left-handed direction or S-wound direction).

_{The inclination angle θ 1} of each liquid introduction hole is not limited to about 25 ° with respect to the axial direction of the nozzle, and can be selected from a range of about 10 to 60 °, for example, 15 to 50 °, preferably 20 to 40 °. , More preferably 23 to 30 °. If the inclination angle is too small, it may be difficult to swirl the liquid, and conversely, if it is too large, the injection pressure may decrease.

_{The inclination angles θ 1} of the plurality of liquid introduction holes are not limited to the same inclination angle, and it is sufficient that the liquid can be swirled. For example, the inclination angles differ by about ± 20 °, preferably ± 10 °, and more preferably ± 5 °. A liquid introduction hole may be included. Therefore, in the present specification and claims, the "same direction" in the circumferential direction of the liquid introduction hole is not limited to the mode in which the inclination angles are completely the same, and if the liquid can be provided with the desired swirling flow. Often, the difference in tilt angle is within the above range, and the orientation is substantially the same when viewed from the nozzle axis.

That is, in the spray nozzle of the present invention, a plurality of liquid introduction holes are substantially in the same direction (substantially the same) so that the liquid passing through the inclination direction of the liquid introduction holes can be swirled in either the right spiral direction or the left spiral direction. It suffices if they are formed at substantially the same inclination angle (in the direction), and it is preferable that they are formed at the same inclination angle in the same direction.

The thickness of the disc-shaped partition wall portion may be 0.1 times or more with respect to the flow path length (length in the nozzle axis direction) of the second cylindrical flow path, for example, 0.1 to 1 times. It is preferably 0.2 to 0.8 times, more preferably 0.3 to 0.6 times, and most preferably 0.4 to 0.5 times. If the thickness of the disc-shaped partition wall portion is too thin, it may be difficult to swirl the liquid.

In the present invention, in addition to the thickness of the disc-shaped partition wall, the number and position of the liquid introduction holes, and the inclination angle θ ₁ , the shapes of the first tapered flow path and the second tapered flow path, which will be described later, are controlled. Thereby, the shape of the holocorn having an elliptical cross section can be adjusted, and by adjusting the shape within the above-mentioned preferable range, the particles can be uniformly atomized over a wide range of injection pressures.

The taper angle θ ₂ of the second tapered flow path is not limited to around 90 °, and may be inclined in a direction in which the diameter (circular diameter) of the flow path increases toward the upstream side, and is 30 to 150. It can be selected from a range of about °, for example, 40 to 130 °, preferably 50 to 120 °, more preferably 60 to 110 °, and most preferably 80 to 100 °. If the taper angle θ ₂ is too small, the injection pressure may decrease, and if it is too large, the turning may be disturbed and it may be difficult to inject a uniform holocorn pattern.

The flow path diameter (diameter perpendicular to the nozzle axis) of the first cylindrical flow path (circular orifice) is not limited to about 60% with respect to the flow path diameter of the second cylindrical flow path, and is 10 to 90%. It can be selected from the range of degrees, for example, 20 to 80%, preferably 30 to 75%, more preferably 50 to 70%, and most preferably 55 to 65%. If the flow path diameter of the first cylindrical flow path is too small, it may be difficult to inject the hollow cone pattern, and conversely, if it is too large, the injection pressure may decrease.

The area of the flow path port of the first cylindrical flow path (cross-sectional area of the flow path in the direction perpendicular to the nozzle axis) is the total area of the introduction port of the liquid introduction hole (the area of the introduction port of the plurality of liquid introduction holes). It is not limited to about 3 times, and can be selected from a range of about 1.5 to 10 times, for example, 2 to 5 times, preferably 2.5 to 4 times, and more preferably 2.8 to 3 times. It is 5.5 times. If the area of the flow path port of the first cylindrical flow path is too small, it may be difficult to inject the hollow cone pattern, and conversely, if it is too large, the injection pressure may decrease.

The total flow path length (the shortest distance from the discharge port to the upstream end of the first cylindrical flow path) of the first tapered flow path and the first cylindrical flow path is the flow of the first cylindrical flow path. For example, 0.2 to 2 times, preferably 0.3 to 1.5 times, more preferably 0.4 to 1.3 times (for example, 0.5 to 1.1 times), more preferably, the road diameter. It is 0.6 to 1 times, most preferably 0.7 to 0.9 times. If this ratio is too small, a pattern having an elliptical cross section may not be formed, and if it is too large, it may be difficult to inject with a hollow cone pattern.

The first tapered flow path may be formed so that the discharge port has an elliptical shape (particularly, an elliptical shape larger than the circular shape of the first cylindrical flow path). Further, the first tapered flow path is not limited to a flow path having a wall surface extending outward from the upstream to the downstream in both the long axis and the short axis of the discharge port, and at least the long axis. It suffices as long as the flow path has a wall surface whose vertical cross-sectional shape extends outward from upstream to downstream.

The vertical cross-sectional shape of the short axis of the discharge port is not limited to a shape that is linearly inclined in a direction away from the axis toward the downstream direction, and may be a linear shape parallel to the center of the nozzle axis in the downstream direction. It may have a curved shape that curves so that the angle with respect to the axis increases toward the axis (a curved shape that curves and expands toward the downstream direction), but from the viewpoint of convenience and the like, a straight line shape is preferable, and the straight line shape is preferable. A shape that is inclined in a shape is particularly preferable.

_{The taper angle θ 3} of the vertical cross-sectional shape on the short axis can be selected from a range of 30 ° or less with respect to the nozzle axis, for example, 20 ° or less, preferably 10 ° or less, more preferably 5 ° or less, and most preferably 3. It is below °. If the taper angle θ ₃ is too large, it may be difficult to adjust the holocorn pattern to an elliptical cross section.

The vertical cross-sectional shape on the long axis of the discharge port is not limited to the shape including the curved portion (curved enlarged portion) and the straight portion (linear enlarged portion), and is from the downstream end of the first cylindrical flow path. It has a curved shape that expands while curving toward the downstream direction to reach the discharge port, and a linear shape that expands linearly from the downstream end of the first cylindrical flow path to the discharge port. However, the shape including the curved portion and the straight portion is preferable from the viewpoint that the hollow cone pattern shape can be maintained without changing the elliptical hollow cone pattern shape with respect to a wide range of injection pressures.

The radius of curvature of the curved portion is, for example, 0.5 to 5.0 mm, preferably 0.8 to 4.0 mm, and more preferably 1.0 to 3.5 mm.

In the virtual circle having the radius of curvature, the angle (central angle) θ ₅ of the fan shape (partial circle) having the curved portion as an arc is, for example, 5 to 80 °, preferably 10 to 60 °, and more preferably 20 to 20 to. It is 50 °, most preferably 30-40 °.

_{The inclination angle θ 6} of the straight line portion with respect to the axis is, for example, 10 to 60 °, preferably 20 to 50 °, and more preferably 25 to 40 °.

_{The taper angle θ 4} (θ _4a × 2) of the vertical cross-sectional shape on the long axis can be selected from a range of about 20 to 120 ° with respect to the nozzle axis, for example, 5 to 100 °, preferably 30 to 80 °, and further. It is preferably 40 to 70 °. If the taper angle θ ₄ is too small, it may be difficult to adjust the cross section of the hollow cone-shaped pattern to an elliptical shape, and conversely, if it is too large, it may be difficult to inject the hollow cone-shaped pattern.

In the present specification and claims, in the first tapered flow path, the taper angle of the vertical cross-sectional shape on the short axis and the long axis of the discharge port is the discharge port when the vertical cross-sectional shape includes a curved shape. It means the angle between the straight lines connecting the intersection with the short axis or the long axis in the above and the downstream end of the first cylindrical flow path (the downstream end located at the shortest distance from the intersection).

When the vertical cross-sectional shape on the long axis of the first tapered flow path is a shape including the curved portion and the straight portion, the flow path length of the region where the vertical cross-sectional shape is the curved portion (flow path on the upstream side). The ratio of the length) to the flow path length (flow path length on the downstream side) of the region where the vertical cross-sectional shape is a straight portion is the former / the latter = 3/1 to 1/3, preferably 2/1 to 1 / 2, more preferably 1.5 / 1-1 / 1.5, most preferably 1.2 / 1-1 / 1.2, and both flow path lengths may be substantially the same length.

The shape of the discharge port is not particularly limited as long as it is an elliptical shape, and the major axis may be about 1.2 times or more the minor axis, but the major axis is short because it is easy to inject with a hollow cone-shaped pattern having an elliptical cross section. The diameter is preferably 1.2 times or more, for example 1.2 to 3 times, preferably 1.3 to 2.5 times, more preferably 1.35 to 2 times, and most preferably 1.4 to 1. It is .65 times. If the major axis is too small with respect to the minor axis, it may be difficult to adjust the cross section of the hollow cone-shaped pattern to an elliptical shape, and conversely, if it is too large, it may be difficult to inject the hollow cone-shaped pattern.

The spray nozzle of the present invention may have a flow path extending from the above-mentioned discharge port formed inside and a disc-shaped partition wall portion, and the external shape is not particularly limited and may be appropriately selected according to the application. it can. The external shape is not limited to a columnar shape, and may be a prismatic shape such as a quadrangle or a hexagon in cross section. Further, the external shape may be a shape having no flange portion, a shape having a screwed portion, or the like.

The spray nozzle of the present invention is not limited to a mode in which the nozzle body and the disc-shaped partition wall portion are independent members, and may be a mode in which the nozzle body and the disc-shaped partition wall portion are integrated.

The liquid ejected from the spray nozzle of the present invention is ejected or sprayed in a hollow cone-like pattern having an elliptical cross section.

In the present invention, as described above, this injection pattern can be adjusted by adjusting the flow path diameter, the flow path length, the taper angle of the tapered portion, the shape of the liquid introduction hole, and the inclination angle θ _1.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1
The spray nozzles shown in FIGS. 1 to 7 were used. The detailed shape is as follows.

Short shaft diameter of discharge port and flow path diameter of first cylindrical flow path: 4.35 mm
Discharge port major axis diameter: 6.6 mm
Taper angle of the first tapered flow path: 55 °
Radius of curvature of the first tapered flow path: 2.3 mm
Flow path length of the first cylindrical flow path: 1.2 mm
Taper angle of the second tapered flow path: 90 °
Total flow path length of the first tapered flow path, the first cylindrical flow path and the second tapered flow path: 5.0 mm
Flow path length of the second cylindrical flow path: 4.5 mm
Thickness of disc-shaped partition wall: 2.0 mm
Opening diameter of circular liquid introduction hole: 1.1 mm
Inclination angle of circular liquid introduction hole: 26 °
Area of the flow path port of the first cylindrical flow path / Total area of the introduction port of the liquid introduction hole: 3.1 / 1
Flow path length of the third cylindrical flow path: 9.8 mm
Flow path diameter of the first cylindrical flow path / total flow path length of the first tapered flow path and the first cylindrical flow path: 1.24 / 1.

When spraying was performed at a low pressure of 0.3 MPa and a high pressure of 3 MPa using this nozzle, the low pressure water amount was 3.9 (L / min) and the high pressure water amount was 11.5 (L / min). When the ratio of to the major axis was measured at a spray distance of 50 mm, it was 2.5 on the low pressure side, and on the high pressure side, ± 2% with respect to 2.5 without unexpectedly large variation in any measurement. It stayed within the change.

Further, with respect to the amount of water sprayed under the low pressure condition (0.3 MPa, 3.9 L / min, 50 mm), the distribution states of the elliptical spray pattern in the minor axis direction (front-back direction) and the major axis direction (left-right direction) are measured. The result is shown in FIG. FIG. 9 shows the water amount density (%) with respect to the distance from the nozzle center (the position corresponding to the center of the spray pattern and the nozzle axis), and the water amount (100%) at the distance where the water amount is maximum. It is shown as a relative value to. The solid line graph shows the water volume distribution in the long axis direction, and the water volume is maximum at a position where the distance from the nozzle center is 50 mm in the right direction, and the peak is at a distance of 50 mm in the left direction as well. Similarly, the broken line graph shows the water volume distribution in the minor axis direction, and peaks at a distance of 10 mm from the nozzle center in both the front-back direction. The amount of water was determined by comparing the filling amount for a container having an opening diameter of 10 mm. Specifically, at a position 50 mm away from the discharge port of the nozzle, a plurality of containers are arranged in a cross shape in the minor axis direction and the major axis direction of the elliptical spray pattern so that the opening faces the discharge port, and water is discharged from the nozzle. Was sprayed and the amount of water filled in the container was compared.

In order to investigate the atomization performance, the phase Doppler method was performed at four locations in the minor axis direction (front-back direction) and major axis direction (left-right direction) of an elliptical spray pattern with a pressure of 0.3 MPa and a water volume of 3.9 (L / min). The average particle size at the water volume distribution peak position ± 5 mm was measured by (PDPA method). As the average particle size, the Sauter mean diameter (D32) of 10,000 measurement droplets was used. The measurement results are shown in Table 1.

Reference example 1
The spray nozzle is the same as that of the first embodiment except that the discharge port has a circular shape with an opening diameter of 4.35 mm and the inclined surface of the first tapered flow path is a flat surface extending from the first cylindrical flow path. Table 2 shows the results of measuring the average particle size of the same pressure and the same amount of water as in Example 1.

From the results of Tables 1 and 2, in Table 1 of the holocorn-shaped pattern having an elliptical cross section, a spray pattern is formed in which the front-back direction and the left-right direction are symmetrical, and in Table 2 of the circular holocorn, the spray is sprayed symmetrically in the left-right and front-back directions. .. The average particle size in the left-right direction of the holocorn-shaped pattern with an elliptical cross section at the same measurement position as the circular holocorn is about the same as that of the circular holocorn spray, but the average particle size in the anteroposterior direction in the elliptical minor axis direction is clear. Agglomerated results were obtained. As a result, when the total sprays of the same pressure and the same flow rate were averaged, the average particle size of the elliptical holocorn could be atomized to about 77% of that of the circular full cone spray.

The spray nozzle of the present invention is not particularly limited as long as it is used to inject a liquid in an elliptical hollow cone-shaped pattern, and can be used in a wide range of applications. For example, in a boiler for power generation, a gas turbine, an engine, etc., fossil fuel can be used. In addition to spray nozzles for spraying, it can also be used for humidification nozzles, disinfection and sterilization nozzles, oil coating nozzles, and the like.

1 ... Discharge port 2 ... First tapered flow path 3 ... First cylindrical flow path 4 ... Second tapered flow path 5 ... Second cylindrical flow path 6 ... Disc-shaped partition wall portion 6a ... Liquid Introduction hole 7 ... Third cylindrical flow path 8 ... Flange portion 8a ... Reference surface 9 ... Spray pattern 10 ... Spray nozzle 11 ... Holocone pattern 12 ... Object to be injected

Claims (10)

A spray nozzle for injecting liquid in a hollow cone-shaped pattern with an elliptical cross section, which extends from this elliptical discharge port in a direction in which the elliptical major axis length decreases and converges to a circular shape. A first tapered flow path, a first cylindrical flow path connected to the first tapered flow path, and a second extending from the first cylindrical flow path in an inclined direction in which the flow path diameter increases. Two tapered flow paths, a second cylindrical flow path connected to the second tapered flow path, and an arrangement across the flow path on the upstream side of the second cylindrical flow path, and A disc-shaped partition wall having a plurality of liquid introduction holes and a third cylindrical flow path extending upstream of the disk-shaped partition wall are provided, and the plurality of liquid introduction holes are concentric on the nozzle axis. A spray nozzle that is formed at intervals and is inclined in the same direction in the circumferential direction of the concentric circles and extends in the axial direction of the nozzle. The spray nozzle according to claim 1, wherein the disc-shaped partition wall portion has 3 to 10 liquid introduction holes. The spray nozzle according to claim 1 or 2, wherein the liquid introduction hole is inclined at 10 to 60 ° with respect to the axial direction of the nozzle. The spray nozzle according to any one of claims 1 to 3, wherein the liquid introduction holes are formed at equal intervals at positions corresponding to the outer periphery of the first cylindrical flow path. The spray nozzle according to any one of claims 1 to 4, wherein the center of the liquid introduction hole is formed at a position corresponding to the outer circumference of the first cylindrical flow path at equal intervals. The spray nozzle according to any one of claims 1 to 5, wherein the major axis is 1.2 times or more the minor axis in the elliptical discharge port. The spray nozzle according to any one of claims 1 to 6, wherein the area of the flow path port of the first cylindrical flow path is 2 to 5 times the total area of the introduction port of the liquid introduction hole. Claim that in the first tapered flow path, the taper angle of the vertical cross-sectional shape on the short axis of the discharge port is 30 ° or less, and the taper angle of the vertical cross-sectional shape on the long axis of the discharge port is 30 to 90 °. The spray nozzle according to any one of 1 to 7. In the first tapered flow path, a curved portion in which the vertical cross-sectional shape on the long axis of the discharge port curves and expands from the downstream end of the first cylindrical flow path toward the downstream direction, and a curved portion downstream from this curved portion. The spray nozzle according to claim 8, which has a shape including a straight portion that expands linearly toward the discharge port and reaches the discharge port. Any of claims 1 to 8, wherein the total flow path lengths of the first tapered flow path and the first cylindrical flow path are 0.2 to 2 times the flow path diameter of the first cylindrical flow path. The spray nozzle according to one item.

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