JP5547802B2 - nozzle - Google Patents

Description

  The present invention relates to a nozzle, and in particular, in a continuous casting machine of steel, it is suitably used for cooling a high-temperature slab, bloom or billet, roll, and the like.

The continuous casting equipment manufactures a wide variety of steel plates, and it is necessary to adjust the spray amount sprayed from the nozzles according to the type of steel plate. Conventionally, either a one-fluid nozzle that injects only water or a two-fluid nozzle that mixes and injects water and air is used as this type of nozzle.
Of these nozzles, the amount of spray can be easily adjusted by changing the pressure balance between water and air to be supplied, and therefore, two-fluid spray is often performed in which water and air are mixed and ejected from the nozzle.

Conventionally, for example, a nozzle 100 shown in FIG. 12 is used. The nozzle 100 forms an orifice by forming an orifice 103 at the tip of an independent hole 102 drilled on the central axis, and providing a notch 104 communicating with the orifice 103 from the injection side.
When the spray amount is changed by the nozzle 100, there is a problem that the spray angle and the flow rate distribution change, and uniform cooling cannot be performed. Specifically, in the nozzle 100, when water and air are mixed and sprayed, if the flow ratio of air to water is lowered and finally only water is injected to reduce the water flow rate, There is a problem that the spray angle in the spray thickness direction becomes small and the spray angle tends to become unstable.

  Further, in the two-fluid nozzle 105 used by mixing liquid (water) and air disclosed in Japanese Patent Publication No. 3-15493 shown in FIG. 13, the tip of the adapter 109 into which the liquid and gas mix and flow A nozzle tip 106 is attached to the nozzle. The nozzle tip 106 is provided with a stirring chamber 107 having a circular cross section and a nozzle soot portion 106a inclined in a separating direction at the front opening of the stirring chamber 107. Two inflows are opposed to the side wall of the stirring chamber 107. A hole 108 is formed.

  In the two-fluid nozzle 105, the spray amount is changed while maintaining the spray angle and distribution constant by adjusting the pressure balance between the liquid and air. However, when the flow rate of the liquid changes, the spray in the spray width direction is changed. There is a problem that the angle fluctuates and cooling unevenness is likely to occur. In particular, if the flow rate ratio of the gas to the liquid is lowered to inject only the liquid, there is a problem that the flow distribution shape in the spray width direction becomes unstable. For example, as shown in FIG. 14A, when two fluids of water and air are sprayed, the spray angle becomes large, but as shown in FIG. 14B, when only one fluid of water is used. The spray angle varies slightly, and there is a problem that a stable spray pattern cannot be obtained when the air-water ratio is varied greatly.

  Furthermore, if liquid (water) and gas (air) are mixed and sprayed at all times, the amount of air consumption increases. When the air consumption increases, the power consumption of the compressor supplying the air increases, resulting in an increase in cost. Therefore, in order to save energy by reducing the power consumption of the compressor that supplies air in response to a request for cost reduction, it is desired to lower the flow rate ratio of air to liquid (or to use only liquid). For this purpose, it is necessary to obtain a stable spray pattern even if the flow rate ratio of air is lowered, but the nozzle cannot sufficiently meet the needs.

Japanese Patent Publication No. 3-15493

  The present invention can stabilize the spray angle and the flow rate distribution without greatly changing even when switching between the two-fluid spray and the one-fluid spray and use the air-water ratio to regulate the amount of gas (air) relative to the liquid. It is an object to provide a nozzle that can reduce air consumption by reducing the air consumption.

In order to solve the above-mentioned problem, the nozzle of the present invention is connected to a liquid supply pipe and an air supply pipe, and performs a combination of one-fluid spraying of only liquid and two-fluid spraying mixed with liquid and air. ,
When the liquid supply amount is high and the liquid pressure is high, only one liquid is sprayed. When the liquid supply amount is low and the liquid supply amount is low, the fluid and air are mixed and two fluids are sprayed.

In the nozzle of the present invention, the spray angle is relatively wide and the flow rate distribution is stable when the liquid pressure is high and the liquid flow rate is increased. One fluid spray is used for spraying. As described above, since the spray angle and the flow rate distribution are stable at a high flow rate of the liquid, the spray angle and the flow rate distribution can be stably maintained even in the case of a single fluid spray of only the liquid.
On the other hand, when the liquid pressure decreases and the liquid becomes a low flow rate, the spray angle and the flow rate distribution become unstable if the one-fluid spraying of only the liquid is continued. Therefore, it switches to the two-fluid spray which mixed air with the liquid. Thus, by adding air, the spray angle and flow rate distribution can be stably sprayed at the same spray angle and flow rate distribution as when only the liquid is sprayed at a high flow rate.

The nozzle provided by the present invention is:
A liquid inflow path connected to the liquid supply pipe is connected to the main fluid flow path having a nozzle hole at the tip through the liquid inflow port, and an air inflow path connected to the air supply pipe is connected to the main fluid flow path through the air inlet. The liquid pressure supplied to the liquid supply pipe varies, while the air pressure supplied to the air supply pipe is a constant pressure.
While the liquid inlet is normally open, the air inlet is opened and closed by a switching valve,
When the liquid pressure of the liquid supplied from the liquid supply pipe to the main fluid flow path is reduced, the switching valve is opened and air is introduced in accordance with the decreasing rate of the liquid pressure to form a two-fluid spray, Except when the hydraulic pressure drops, it is a single fluid injection of liquid only.
The fluid flow rate of only the liquid at the time of the one-fluid injection, the fluid flow rate of the liquid flow rate at the time of the two-fluid injection, and the air flow rate are equal, and at the time of one-fluid injection that is jetted from the same nozzle at the tip of the main fluid channel The spray angle and the flow rate distribution are equal to the spray angle and the flow rate distribution when the two fluids are injected.

Specifically, the valve body of the switching valve at the air inlet is urged by a spring, and the air pressure supplied from the air supply pipe is set to a constant pressure P2, while the spring pressure of the spring is set to P3.
When the liquid pressure P1 of the liquid supplied from the liquid supply pipe is high and P1 + P3> P2, only the liquid is sprayed, and when the liquid pressure P1 is low and P1 + P3 <P2, the switching valve is operated with air pressure. It is opened, and air is introduced into the main fluid flow path in accordance with the decreasing rate of the hydraulic pressure to spray two fluids.

In the above configuration, the spring pressure P3 of the spring that biases the valve body of the switching valve that closes the air inlet does not vary, and the air pressure P2 does not vary, and is constant, so the liquid pressure P1 of the liquid is constant. If it is high, the fluid pressure P1 acts on the spring pressure P3 and acts to close the air inlet with the valve body, so that the inflow of air can be prevented.
On the other hand, when the hydraulic pressure P1 decreases, when the air pressure P2 becomes larger than the hydraulic pressure P1 + the spring pressure P3, the air inlet automatically opens the air inlet by the air pressure, the air flows in, and the air mixes with the liquid. It becomes spraying. In addition, the air flow rate increases automatically when the inflow amount of air fluctuates according to the pressure of the liquid and the liquid pressure decreases and the liquid flow rate decreases.
In this way, when air is automatically applied in accordance with fluctuations in hydraulic pressure, the spray angle and flow distribution can be stably sprayed at the same spray angle and flow distribution as when only the liquid is sprayed at a high flow rate. Can do.
A valve body biased by a spring may also be provided at the liquid inlet, and the spring pressure may be different from the spring pressure of the spring provided at the air inlet.

  The switching valve at the air inlet may be an electromagnetic valve, and when the hydraulic pressure supplied from the liquid supply pipe becomes less than a set value, the switching valve is controlled to be opened to spray the two fluids.

The set value of the fluid pressure is in the range of 0.005 MPa to 0.9 MPa, and the air / water ratio, which is the ratio of the air amount to the maximum liquid amount during two-fluid spraying, is in the range of 0.5 to 5.0. Is preferred.
If the switching valve is an electromagnetic valve and the switching valve is automatically opened and closed according to the fluid pressure, the nozzle structure can be simplified. In addition, it is more preferable that the switching valve can adjust the opening angle according to the hydraulic pressure.

  The specific structure of the nozzle is not particularly limited, as long as the supply fluid is only a liquid and it is a one-fluid spray or a structure in which air is mixed with a liquid to form a two-fluid spray. A nozzle having a configuration in which fluids collide with each other and a spray angle can be specified by the collision is preferably used.

As the nozzle to be used, a large-diameter main fluid flow path is provided along the central axis of the nozzle body, and a plurality of independent holes are provided at the tip thereof. While closing the tip,
A diametrical cut portion is provided on the injection side end surface of the body, and the cut portion has a required width of a circular arc shape or a tapered shape on the bottom surface, and both side surfaces sandwiching the bottom surface are defined as the central axis. Inclined so that the parallel or opening tip expands in the away direction,
A side surface on the side of the central axis that is separated from the front end closing portion of each independent hole is cut out by the cut portion to provide a right-angled L-shaped nozzle that opens on the side surface and the bottom surface of the cut portion. So that the fluid returns from the closed end of the nozzle to the nozzle,
The spray thickness is increased by the collision of fluids ejected from each nozzle formed opposite to both sides of the notch, and the fluid ejected from each nozzle in the notch is It is preferable that the spray width is regulated by guiding by the insertion portion.

As described above, the nozzle of the present invention adjusts the liquid pressure to adjust the spray amount of the liquid, while keeping the spray angle and distribution from changing, thereby enabling uniform cooling within a required range. Therefore, it is most suitably used for cooling a steel plate disposed in a secondary cooling zone in a continuous casting facility. It is effective in the process of changing the cooling rate of steel plates such as controlled cooling of rolling (thick plate) and runout table of rolling (thin plate).
In addition, it is not limited to this use, It uses suitably also for another use.

According to the present invention, it is possible to easily and automatically adjust to a fluid spray of only liquid and a two-fluid spray of liquid and air by changing the fluid pressure according to the cooling condition to be sprayed. In addition, when the flow rate of the liquid is changed, the one-fluid spray of only the liquid is performed at the high flow rate, and the two-fluid spray in which the liquid and air are mixed at the low flow rate. The flow rate distribution can be stably maintained without changing between the one-fluid spraying at the high flow rate and the two-fluid spraying at the low flow rate.
Moreover, since the flow ratio (gas / water ratio) of the gas to the liquid can be lowered while maintaining a stable spray pattern, the power consumption of the gas supply compressor can be suppressed, and energy saving can be achieved.

1 is an overall view of a nozzle according to a first embodiment of the present invention. It is a front view which shows mixing of the said 1st Embodiment. It is a principal part expanded sectional view of FIG. (A) is drawing which shows the spray angle at the time of 1 fluid spray with a large liquid flow rate, (B) is drawing which shows the spray angle at the time of 2 fluid spray with a small liquid flow rate. It is sectional drawing of the nozzle of 2nd Embodiment. FIG. 6 is a cross-sectional view orthogonal to FIG. 5. It is a front view of the injection side of the nozzle of 2nd Embodiment. It is a rear view of the inflow port side of the nozzle of 2nd Embodiment. (A) is the principal part expanded sectional view of FIG. 5, (B) is the principal part expanded sectional view of FIG. It is a front view of the nozzle of 3rd Embodiment. It is a principal part expanded sectional view of the nozzle of 4th Embodiment. It is sectional drawing of the nozzle of a prior art example. It is sectional drawing of the nozzle of another prior art example. (A) (B) is drawing which shows the problem of a prior art example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a first embodiment. The nozzle 1 of the first embodiment is arranged in a secondary cooling zone in a continuous casting facility and used for cooling a high-temperature slab.

  As shown in FIGS. 1 and 2, the nozzle 1 includes a liquid inflow path 3 connected to the liquid supply pipe 2, an air inflow path 5 connected to the air supply pipe 4, and a nozzle 6 a at the tip, and the main fluid flow path 6. It has.

  As shown in FIG. 2, the spray type automatic switching valve 7 is located in the nozzle 1 at the boundary position between the liquid inflow path 3 and the main fluid flow path 6 and between the liquid inflow path 3 and the air inflow path 5. (Hereinafter abbreviated as “switching valve 7”).

The switching valve 7 includes a flow path 7a orthogonal to the main fluid flow path 6, with one end of the flow path 7a serving as a liquid inlet 7b communicating with the liquid inflow path 3, and the other end of the flow path 7a being air. An air inlet 7c that communicates with the inflow path 5 is disposed opposite the liquid inlet 7b. A spring 8 is accommodated in the flow path 7 a of the switching valve 7, and a valve body 9 that closes the air inlet 7 c is disposed at the tip of the spring 8, and the air inlet 7 c is opened and closed by the valve body 9. ing.
On the other hand, the valve body is not opened on the liquid inlet 7b side, but is normally opened, and the liquid is always allowed to flow into the flow path 7a. The liquid pressure P1 of the liquid and the spring pressure P3 of the spring 8 are applied to the valve body 9. It is assumed that it is always loaded.

The air supply pipe 4 is connected to the compressor 30, and the air pressure supplied to the air inflow passage 5 through the air supply pipe 4 is always a constant pressure P2.
Therefore, when the liquid pressure P1 of the liquid supplied from the liquid supply pipe 2 is high and P1 + P3> P2, the valve body 9 is closed and air does not flow into the flow path 7a of the switching valve 7, Only the liquid is supplied to the fluid flow path 6.
On the other hand, when the hydraulic pressure P1 is low and P1 + P3 <P2, the valve body 9 is opened by the air pressure, air flows into the flow path 7a of the switching valve 7, and the main fluid flow path 6 is mixed with liquid and air. Liquid is supplied.

  The liquid pressure P1 of the liquid is set by the discharge pressure of the pump 31 connected to the liquid supply pipe 2, and the discharge pressure is set according to the type of steel sheet cooled by the nozzle, the temperature of the steel sheet, and the like, and the liquid flow rate is set. ing.

As described above, in the nozzle 1 of the present invention, when the hydraulic pressure P1 is high and P1 + P3> P2, the valve body 9 is closed and only the liquid is supplied to the main fluid flow path 6 from the nozzle. The spray is a one-fluid spray of only liquid.
At the time of this one-fluid spray, the spray angle θ in the width direction is a relatively wide θ1 as shown in FIG.
On the other hand, when the hydraulic pressure P1 is low and P1 + P3 <P2, the valve body 9 is opened by the air pressure, air flows into the flow path 7a of the switching valve 7, and the main fluid flow path 6 is mixed with liquid and air. The liquid is supplied, and the spray from the nozzle is a two-fluid spray in which air and liquid (water) are mixed.
When the liquid flow rate decreases, the spray angle varies so as to be narrow, but the spray angle is expanded by adding air to the liquid to form two fluids. Therefore, as shown in FIG. 4B, the spray angle θ2 (θ2≈θ1) is the same as that in FIG. 4A when spraying one fluid, and the flow rate distribution in the thickness direction is also kept uniform. In this way, even if the liquid flow rate is reduced, the spray angle and distribution fluctuations can be suppressed by adding air to form a two-fluid spray.

  Even if the shape of the main fluid flow path 6 of the nozzle 1 and the shape of the nozzle hole at the tip are different, the spray angle is relatively widened when the liquid flow rate to be ejected is large, and the spray angle is relatively large when the liquid flow rate is small. However, as in the present invention, when the liquid flow rate decreases, air is automatically added, and the fluid flow rate of the sum of both the liquid and air is made substantially equal to the flow rate when only the liquid is used. The reduction in the angle can be suppressed to be equivalent to the case where the liquid flow rate is large.

5 to 9 show a second embodiment.
The nozzle 10 used in the second embodiment (hereinafter abbreviated as “nozzle 10”) is different in the structure of the nozzle 1 used in the first embodiment and the nozzle side of the main fluid flow path 6. That is, the main fluid flow path 6 communicates with the liquid inflow path 3 connected to the liquid supply pipe 2 via the switching valve 7 and the air inflow path 5 connected to the air supply pipe 4 as in the first embodiment. In addition, the liquid can be sprayed by switching only one fluid of the liquid from the nozzle or two fluids in which air is mixed with the liquid.

A partition wall 19 is provided on the central axis of the nozzle on the front end side of the cylindrical main fluid flow path 6 provided along the center line of the nozzle body 15, and independent independent holes 17 and 18 are provided on both sides of the partition wall 19. Provided.
The tip portions of the individual holes 17 and 18 form tapered tip closing portions 17a and 18a that gradually reduce the flow channel area. Further, a notch 22 is recessed from the tip of the injection side of the body 15 and communicates with one side of the tip closing portions 17a, 18a facing each other. And the opening of the front-end | tip closing parts 17a and 18a connected by the notch part 22 is made into the nozzle holes 20 and 21. FIG.

  The notch 22 has a bottom surface 22a that is recessed in an arc shape that opens to the injection side, and a side surface 22b that is parallel to the axial direction of the nozzle 10. Note that the radius of curvature R of the arc of the bottom surface 22a is in the range of 4 to 50 mm, and is determined according to the body size and the required spray width.

  The nozzle holes 20 and 21 have an L-shaped cross section in which the bottom surface 22a and the side surface 22b of the cut portion 22 are orthogonal to each other. As shown in FIG. 9 (A), the tip closing portions 17a and 18a are U-shaped portions 17b having a shape in which the fluid is returned to the partition wall 19 side by U-turning from the tips of the independent holes 17 and 18 to the nozzles 20 and 21. 18b is provided. Moreover, the taper part 23 which spreads in a separation direction is provided continuously from the injection side front-end | tip of the side 22b of the notch part 22. As shown in FIG.

  In the nozzle 10 of the second embodiment, the injection process of the first fluid and the second fluid is the same when only one liquid or two fluids composed of a mixture of liquid and air flows into the main fluid flow path 6. This will be described below.

As shown in FIGS. 9A and 9B, the fluid flowing into the main fluid flow path 6 flows separately into the two independent holes 17 and 18 respectively.
The fluids that flow into the independent holes 17 and 18 increase the flow velocity with the reduction of the flow path area at the tip closing portions 17a and 18a, and the fluids that flow out from the opposed nozzles 20 and 21 are cut into the cut portions 22 respectively. Collide within.

  The collision promotes the diffusion of fluid in the spray thickness direction T and the spray width direction W. At that time, since the U-shaped portions 17b and 18b are formed so as to return the fluid to the partition wall 19 side from the tip of the independent holes 17 and 18 to the nozzles 20 and 21, a little fluid is ejected from each nozzle 20 and 21. Flows in the return direction. While stirring is performed by this flow, the collision of the two flows can be enhanced, and even when the flow rate is small, the injection angle θn in the spray thickness direction T and the injection angle θw in the spray width direction W can be sufficiently secured.

Further, the colliding fluid is guided in the spray thickness direction T by the side surface 22 b of the cut portion 22 and smoothly guided in the spray width direction W by the arc-shaped bottom surface 22 a of the cut portion 22. Therefore, it is possible to provide a stable spray angle θn in the spray thickness direction T and a spray angle θw in the spray width direction W even when the liquid flow rate varies.
In particular, with respect to the spray width direction W, since the bottom surface 22a of the notch 22 serving as a guide wall has an arc shape, spraying with less energy loss is possible.

  Finally, regardless of the liquid flow rate, the spray in the spray thickness direction T stabilized between the side surfaces 22b of the cut portion 22 is guided by the tapered portion 23 continuous from the side surface 22b of the cut portion 22 to the tip side. Thus, the injection angle θn is increased.

  As described above, since the spray is sufficiently diffused, the flow width distribution in the spray width direction can be kept uniform even if the liquid flow rate fluctuates. Further, since the nozzle holes 20 and 21 have an L-shaped cross section in which the bottom surface 22a and the side surface 22b of the cut portion 22 are orthogonal to each other, the openings of the nozzle holes 20 and 21 can be enlarged, and the upper limit value of the flow rate can be increased. In addition, since the nozzles 20 and 21 can be enlarged without changing the size of the body 15, the size of the nozzle 10 can be reduced.

Moreover, since the spray pattern is stable even when the liquid flow rate fluctuates, the flow rate of gas to liquid (air / water ratio) can be lowered, and the power consumption of the compressor for gas supply is also reduced, saving energy. Can also be achieved.
Since the spray pattern is stable even if the flow ratio of gas to liquid (air / water ratio) is lowered, the spray angle can be kept stable without changing the spray angle even when only one liquid is sprayed.

  According to the nozzle 10 described above, the spray thickness and the spray width can be increased by the collision and diffusion of the fluid flowing out from the opposed nozzle holes of the individual holes. In addition, since the spray is guided and sprayed by the side surface and the arc-shaped bottom surface of the cut portion, a stable spray thickness and spray width can be obtained even when the flow rate varies, and the flow rate distribution is also uniform. Can be kept in. Furthermore, since the independent hole is provided with a front end closing portion with a reduced flow path area at a position before the nozzle hole, the fluid collides at high speed and high pressure, and the spray diffusion effect can be enhanced. Furthermore, by providing the U-shaped portion from the tip of the independent hole to the nozzle hole, the fluid ejected from each of the opposing nozzle holes flows in the return direction slightly and stirring is performed, and the collision of the two flows can be enhanced. Even when the flow rate is small, a sufficient spray area can be secured.

  In addition, as described above, the spray pattern is stable even when the liquid flow rate varies, so even if the flow rate ratio of gas to liquid (gas / water ratio) is lowered, it can be used without replacing the nozzle. In addition, the nozzle can be used for both the one-fluid spraying of only the liquid and the two-fluid spraying mixed with the liquid and air. In addition, since the air-water ratio can be reduced, the power consumption of the gas supply compressor can be suppressed, and energy saving can be achieved.

FIG. 10 shows a third embodiment.
In the nozzle of the third embodiment, instead of the switching valve that biases the valve body with the spring of the first embodiment to open and close the air inlet, an electromagnetic switching valve 50 is interposed in the air inlet, When the hydraulic pressure supplied to the electromagnetic switching valve 50 by the liquid supply pipe 2 becomes equal to or lower than the set value, the electromagnetic switching valve 50 is opened, and air is mixed with the liquid to form a two-fluid spray.
Since the structure of the nozzle is the same as that of the second embodiment, the description is omitted.

  The set value of the hydraulic pressure for switching from the one-fluid spray of only the liquid to the two-fluid spray is in the range of 0.005 MPa to 0.9 MPa. And the air-water ratio which is ratio of the air quantity with respect to the maximum liquid quantity at the time of 2 fluid spraying is made into the range of 0.5-5.0.

FIG. 11 shows a fourth embodiment.
In the first to third embodiments, the air supply pipe is joined from the side with respect to the liquid supply pipe provided along the central axis. However, the fourth embodiment has a double pipe configuration and the inner cylinder 40. Air is circulated through the inner central flow path, and a mixing adapter 43 accommodating a switching valve 7C having a spring and a valve body is attached to the distal end side of the inner cylinder 40.
An outer cylinder 41 is disposed with a liquid flow path 42 formed in the outer periphery of the inner cylinder 40, and a nozzle body 45 is connected to the tip of the outer cylinder 41.
Further, adapters (not shown) connected to the air supply source and the liquid supply source via pipes are connected to the proximal ends of the inner cylinder 40 and the outer cylinder 41, respectively.

In the fourth embodiment, when the pressure of the liquid flowing in the outer liquid flow path 42 decreases and the air pressure supplied into the inner cylinder 40 becomes higher, the switching valve 7C is opened, and the air is fed to the tip of the mixing adapter 43. It is ejected from the opening 43a and mixed in the liquid. The mixed fluid of liquid and air is ejected from an ejection port 45 a at the tip of the nozzle body 45.
When the liquid pressure is high, one-fluid spray of only the liquid is performed while the switching valve 7C is closed.

DESCRIPTION OF SYMBOLS 1, 10 Nozzle 2 Liquid supply pipe 3 Liquid inflow path 4 Air supply pipe 5 Air inflow path 6 Main fluid flow path 7 Switching valve 8 Spring 9 Valve body 50 Electromagnetic switching valve

Claims (2)

A liquid inflow path connected to the liquid supply pipe is connected to the main fluid flow path having a nozzle hole at the tip through the liquid inflow port, and an air inflow path connected to the air supply pipe is connected to the main fluid flow path through the air inlet. The liquid pressure supplied to the liquid supply pipe varies, while the air pressure supplied to the air supply pipe is a constant pressure.
While the liquid inlet is normally open, the air inlet is opened and closed by a switching valve,
Wherein the liquid supply tube when the liquid pressure drop of the liquid supplied to said main fluid flow path, wherein the switching valve is a morphism 2 fluid injection introduces air in accordance with the rate of decrease is open the fluid pressure, Except when the hydraulic pressure is reduced, it is a one-fluid jet of liquid only,
The fluid flow rate of only the liquid at the time of the one-fluid injection, the fluid flow rate of the liquid flow rate at the time of the two-fluid injection, and the air flow rate are equal, and at the time of one-fluid injection that is jetted from the same nozzle at the tip of the main fluid channel nozzles, characterized in that the spray angle and flow rate distribution and the second fluid ejection spray angle and flow rate distribution at the time of is equal to become configured. The valve body of the switching valve at the air inlet is urged by a spring, and the air pressure supplied from the air supply pipe is a constant pressure P2, while the spring pressure of the spring is P3,
Hydraulically P1 liquid pressure supplied from the liquid supply line, P1 + P3> only the liquid is morphism injection when the P2, the pressure P1 is at a low pressure, P1 + P3 <said switching valve in the air pressure when the P2 the opening a nozzle according to claim 1 which has a configuration for morphism 2 fluid injection.

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