JP2022096393A - Spray device - Google Patents

Abstract

To provide a spray device with a suction type two-fluid nozzle, which makes it easy to arbitrarily adjust an amount of spray of liquid from the nozzle and makes it possible to greatly change an amount of spray.SOLUTION: In a spray device including a suction type two-fluid nozzle 3 and provided with a proportional control valve in a compressed-air supply passage communicating with the two-fluid nozzle 3, a leading end portion of the two-fluid nozzle 3 has a double pipe structure; a liquid jet port 14 is formed in a leading end of an inner pipe 11; a compressed-air jet port 16 is formed at a leading end of an outer pipe 12; the liquid jet port 14 is formed so as to project from the compressed-air jet port 16; a liquid is sucked by a flow of compressed air from the compressed-air jet port 16; a liquid is sprayed from the liquid jet port 14 together with compressed air; and when an inner diameter of the compressed-air jet port 16 is D, a projecting length of the liquid jet port 14 from the compressed-air jet port 16 is L, and a gap interval between the inner tube 11 and the outer tube 12 is C, a value of L/D is 0.45 or less and a value of L/C is 6.0 or less.SELECTED DRAWING: Figure 2

Description

The present invention relates to a spraying device, and more particularly to a spraying device provided with a suction type two-fluid nozzle.

Conventionally, a two-fluid nozzle that sprays a liquid together with compressed air is known. Among the bifluid nozzles, there is a suction type bifluid nozzle that sucks the liquid by the negative pressure generated by the flow of the compressed air and sprays the liquid together with the compressed air. In the suction type two-fluid nozzle, the amount of liquid sprayed from the nozzle can be changed by changing the pressure of the compressed air supplied to the nozzle. Patent Document 1 discloses a spraying device provided with a suction-type two-fluid nozzle and a proportional control valve provided in a compressed air supply path for supplying compressed air to the nozzle. It is possible to change the pressure of the compressed air supplied to the nozzle.

Utility Model Registration No. 3218246 Gazette

As described above, in the suction type two-fluid nozzle, the amount of liquid sprayed from the nozzle can be changed by changing the pressure of the compressed air supplied to the nozzle, but the amount of liquid sprayed can be changed by the pressure of the compressed air. Precise control is difficult, for example, the relationship between the pressure of the compressed air and the amount of liquid spray does not become a monotonous increase, or the amount of liquid spray does not increase so much even if the pressure of the compressed air is increased. Sometimes.

The present invention has been made in view of the above circumstances, and an object thereof is a spraying device provided with a suction type two-fluid nozzle, and it is easy to arbitrarily adjust the amount of liquid sprayed from the nozzles. It is an object of the present invention to provide a spraying device capable of greatly changing the amount of spraying.

The spraying device of the present invention that has been able to solve the above problems is a two-fluid nozzle, a liquid storage unit in which the liquid sprayed from the two-fluid nozzle is stored, and an air compressor that supplies compressed air to the two-fluid nozzle. A spraying device that communicates with a two-fluid nozzle and an air compressor, and has a compressed air supply path through which compressed air from the air compressor passes, and a proportional control valve provided in the compressed air supply path; The tip has a double pipe structure with an inner pipe and an outer pipe, a liquid spout is formed at the tip of the inner pipe, a compressed air spout is formed at the tip of the outer pipe, and the liquid spout is a compressed air jet. Formed protruding from the outlet, the flow of compressed air from the compressed air outlet sucks the liquid from the reservoir, and the liquid is sprayed with the compressed air from the liquid outlet; the inner diameter of the compressed air outlet is D, liquid. When the protrusion length of the ejection port from the compressed air ejection port is L and the gap between the inner tube and the outer tube is C, the L / D value is 0.45 or less and the L / C value is 6. It is characterized by being 0 or less.

According to the spraying device of the present invention, by increasing the pressure of the compressed air, the amount of liquid sprayed from the two-fluid nozzle can be increased in a monotonous relationship. Therefore, by adjusting the pressure of the compressed air supplied to the two-fluid nozzle with the proportional control valve provided in the compressed air supply path, it becomes easy to arbitrarily change the spray amount. In addition, the spray amount can be controlled in a wide range of compressed air pressure, and the spray amount can be significantly changed.

The L / C value is preferably 1.2 or more and 5.5 or less. As a result, the relationship between the compressed air pressure and the spray amount becomes close to a straight line, and it becomes easy to arbitrarily change the spray amount regardless of whether the compressed air pressure is high or low.

(2) The space between the inner pipe and the outer pipe at the tip of the fluid nozzle may be partially closed when viewed from the compressed air outlet side. By configuring the tip of the two-fluid nozzle in this way, it becomes easy to increase the flow velocity of the compressed air ejected from the compressed air outlet and increase the amount of liquid sprayed from the liquid outlet.

In the spraying device of the present invention, the amount of liquid sprayed from the bifluid nozzle can be increased monotonically by increasing the pressure of the compressed air. Therefore, by adjusting the pressure of the compressed air supplied to the two-fluid nozzle with the proportional control valve provided in the compressed air supply path, it becomes easy to arbitrarily change the spray amount. In addition, the spray amount can be controlled in a wide range of compressed air pressure, and the spray amount can be significantly changed.

A configuration example of the spraying device of the present invention is shown. A configuration example of a two-fluid nozzle provided in the spraying device of the present invention is shown, and an axial cross-sectional view of the tip of the two-fluid nozzle is shown. A configuration example when the two-fluid nozzle is viewed from the tip side is shown.

The present invention relates to a spraying device, and more particularly to a spraying device provided with a suction type two-fluid nozzle. In the suction type two-fluid nozzle, liquid is sprayed from the nozzle nozzle together with compressed air. At this time, the sprayed liquid is stored in the liquid storage section and is generated by the flow of compressed air supplied to the nozzle. The liquid is sucked from the liquid storage part by the negative pressure and sprayed from the nozzle together with the compressed air. Therefore, the amount of liquid sprayed from the nozzle changes depending on the flow velocity of the compressed air, that is, the pressure.

In this way, with the suction type two-fluid nozzle, the amount of liquid spray can be adjusted by changing the pressure of the compressed air, but it is actually not possible to accurately control the amount of liquid spray by the pressure of the compressed air. It is difficult, for example, the relationship between the pressure of the compressed air and the amount of the liquid spray may not be a monotonous increase, or the amount of the liquid spray may not increase so much even if the pressure of the compressed air is increased. On the other hand, the spraying device of the present invention can easily control the spraying amount of the liquid arbitrarily by the pressure of the compressed air, and can greatly change the spraying amount. Hereinafter, the spraying apparatus of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments shown in the drawings.

FIG. 1 shows a configuration example of the spraying device of the present invention, FIG. 2 shows a configuration example of a two-fluid nozzle provided in the spraying device shown in FIG. 1, and an axial cross section of the tip of the two-fluid nozzle. The figure is shown. The spraying device 1 includes a two-fluid nozzle 3, a liquid storage unit 4 for storing the liquid sprayed from the two-fluid nozzle 3, an air compressor 5 for supplying compressed air to the two-fluid nozzle 3, and a two-fluid nozzle 3. It has a compressed air supply path 6 that communicates with the air compressor 5 and allows the compressed air from the air compressor 5 to pass through, and a proportional control valve 7 provided in the compressed air supply path 6. In FIG. 1, the spray unit 2 includes a two-fluid nozzle 3 and a liquid storage unit 4. A plurality of spray units 2 are installed, and each spray unit 2 is connected to a compressed air supply path 6 and a liquid supply path 8 for supplying a liquid to the liquid storage unit 4. In the two-fluid nozzle 3, the liquid is sucked from the liquid storage unit 4 by the flow of the compressed air supplied from the air compressor 5, and the liquid is sprayed together with the compressed air from the two-fluid nozzle 3, and at this time, the liquid is sprayed into the compressed air supply path 6. By adjusting the opening degree of the proportional control valve 7 provided, the pressure of the compressed air supplied to the bifluid nozzle 3 can be adjusted. This makes it possible to change the amount of liquid sprayed from the two-fluid nozzle 3.

As shown in FIG. 2, the bifluid nozzle 3 has a compressed air passage 15 and a liquid passage 13, in which compressed air supplied from an air compressor 5 flows through the compressed air passage 15, and a liquid storage unit is formed in the liquid passage 13. The liquid sucked from 4 flows. The compressed air passage 15 has a compressed air outlet 16 formed on one side, and the other side communicates with a compressed air supply path 6 connecting the two-fluid nozzle 3 and the air compressor 5. The liquid passage 13 has a liquid outlet 14 formed on one side thereof, and the other side communicates with the liquid storage unit 4. Examples of the liquid sprayed from the two-fluid nozzle 3 include water and a chemical solution.

The liquid storage unit 4 stores the liquid sprayed from the two-fluid nozzle 3. One side of the liquid passage 13 communicating with the liquid storage unit 4 is formed so as to suck the liquid stored in the liquid storage unit 4, and one side of the liquid passage 13 opens at the lower portion (preferably the bottom) of the liquid storage unit 4. It is preferably formed so as to.

The liquid storage unit 4 may be formed so that the liquid sprayed from the two-fluid nozzle 3 is temporarily stored, and does not have to be formed in a very large capacity. The capacity of the liquid storage unit 4 is, for example, preferably 100 mL or less, more preferably 50 mL or less, whereby the spray unit 2 can be formed compactly. On the other hand, from the viewpoint of securing the liquid storage amount of the liquid storage unit 4 and stably supplying the liquid to the two-fluid nozzle 3, the capacity of the liquid storage unit 4 is preferably 5 mL or more, more preferably 10 mL or more.

It is preferable that the liquid storage unit 4 is connected to a liquid supply path 8 for supplying the liquid to the liquid storage unit 4. The liquid supply path 8 may have one side communicating with the liquid storage unit 4 and the other side communicating with the water tap or the liquid storage tank. When the other side of the liquid supply path 8 communicates with the liquid storage tank, a liquid feeding means such as a pump is provided in the liquid supply path 8, whereby the liquid stored in the liquid storage tank passes through the liquid supply path 8. The liquid may be sent to the liquid storage unit 4. The liquid supply path 8 may be connected to only one liquid storage unit 4, or may be connected to a plurality of liquid storage units 4. In FIG. 1, three liquid storage units 4 are connected to the liquid supply path 8.

The liquid supply path 8 may be provided with a valve that operates according to the liquid level height of the liquid storage unit 4, whereby it is possible to prevent the liquid from overflowing from the liquid storage unit 4. For example, when the liquid level detecting means is provided in the liquid storage unit 4, the liquid level detecting means detects the liquid level of the liquid in the liquid storage unit 4, and the liquid level of the liquid in the liquid storage unit 4 becomes a predetermined value or more, the valve is activated. It is preferable that the liquid is operated so as to stop the supply of the liquid to the liquid storage unit 4. Further, as a liquid level detecting means, a float is provided in the liquid storage unit 4, a valve is provided at the end of the liquid supply path 8 on the liquid storage unit 4 side, and the float and the valve are connected to form a so-called ball tap, which is above and below the float. The movement may be linked with the movement of opening and closing the valve.

The liquid storage unit 4 is preferably provided in close proximity to the two-fluid nozzle 3 from the viewpoint of allowing the liquid to be suitably sucked from the liquid storage unit 4 by the flow of compressed air. The height difference between the liquid level of the liquid storage unit 4 and the liquid ejection port 14 of the two-fluid nozzle 3 is, for example, preferably 20 cm or less, more preferably 15 cm or less, still more preferably 10 cm or less. The liquid outlet 14 of the two-fluid nozzle 3 is preferably located at a position higher than the liquid level of the liquid storage unit 4. The horizontal separation distance between one end and the other end of the liquid passage 13 is, for example, preferably 30 cm or less, more preferably 20 cm or less, still more preferably 15 cm or less.

One fluid nozzle 3 may be provided for one liquid storage unit 4, or a plurality of two fluid nozzles 3 may be provided. In the latter case, the plurality of two-fluid nozzles 3 may be installed so as to spray the liquid in different directions, or may be configured to spray the liquid from the plurality of two-fluid nozzles 3 in the same direction. , In addition, the configuration may be a combination of these. Further, a plurality of two-fluid nozzles 3 may be installed so that the extension lines of the liquid ejection ports 14 of the nozzles intersect each other. By installing a plurality of the two-fluid nozzles 3 in this way, the liquids sprayed from the nozzles collide with each other, and the sprayed liquid can be further atomized.

The air compressor 5 is provided to supply compressed air to the bifluid nozzle 3. A compressed air supply path 6 is provided in communication with the two-fluid nozzle 3 and the air compressor 5, and the compressed air discharged from the air compressor 5 passes through the compressed air supply path 6 and enters the compressed air passage 15 of the two-fluid nozzle 3. It is introduced and ejected from the compressed air outlet 16 at the tip of the compressed air passage 15.

The compressed air supply path 6 is provided with a proportional control valve 7 whose opening degree can be arbitrarily adjusted. By adjusting the opening degree of the proportional control valve 7, the pressure of the compressed air supplied to the bifluid nozzle 3 can be adjusted. As the proportional control valve 7, known valves such as a ball valve, a gate valve, a globe valve, a needle valve, and a butterfly valve can be used. The proportional control valve 7 is preferably configured so that the opening degree can be adjusted by a signal from the outside, whereby the adjustment of the opening degree can be controlled. As such a valve, an electromagnetic proportional control valve 7 can be used.

In FIG. 1, a control unit 9 is provided, and the control unit 9 is electrically connected to the proportional control valve 7. The opening degree of the proportional control valve 7 can be adjusted by the signal from the control unit 9. The electrical connection may be made by wire or wirelessly. Further, in FIG. 1, a humidity measuring means 10 is further provided, and the humidity of the spray target space is measured by the humidity measuring means 10 in which the humidity measuring means 10 is electrically connected to the control unit 9, and the measured value is used. Based on this, the control unit 9 can determine the opening degree of the proportional control valve 7. As the humidity measuring means 10, a hygrometer, a humidity sensor, or the like can be used.

(2) The pressure (gauge pressure) of the compressed air supplied to the fluid nozzle 3 is preferably adjustable in the range of, for example, 0.8 MPa or less, and the pressure range is more preferably 0.7 MPa or less. 6 MPa or less is more preferable. The lower limit of the pressure range is not particularly limited, and may be 0.01 MPa or more, 0.02 MPa or more, or 0.03 MPa or more. The liquid spraying from the bifluid nozzle 3 may be performed only in a part of the pressure range. For example, when the compressed air pressure is low, the liquid is not sprayed from the bifluid nozzle 3. May be.

The compressed air supply path 6 may be connected to only one two-fluid nozzle 3 or may be connected to a plurality of two-fluid nozzles 3. In FIG. 1, three bifluid nozzles 3 are connected to the compressed air supply path 6. When a plurality of two-fluid nozzles 3 are connected to the compressed air supply path 6, one proportional control valve 7 is provided in the compressed air supply path 6, and one proportional control valve 7 provides compressed air of the plurality of two-fluid nozzles 3. The pressure may be adjustable, and a plurality of proportional control valves 7 are provided corresponding to each two-fluid nozzle 3, and the two-fluid nozzle 3 is provided by the proportional control valve 7 provided corresponding to each two-fluid nozzle 3. The pressure of the compressed air supplied to each may be adjustable. In FIG. 1, one proportional control valve 7 is provided in the compressed air supply path 6, and the compressed air pressure of a plurality of two fluid nozzles 3 can be adjusted by one proportional control valve 7.

As shown in FIG. 2, the bifluid nozzle 3 has a double pipe structure in which the tip portion has an inner pipe 11 and an outer pipe 12, and a liquid passage 13 is formed in the internal space of the inner pipe 11, and the inner pipe 11 is formed. A compressed air passage 15 is formed in the space between the outer pipe 12 and the outer pipe 12. A liquid outlet 14 is formed at the tip of the inner pipe 11, and a compressed air outlet 16 is formed at the tip of the outer pipe 12. The compressed air outlet 16 is formed so as to surround the liquid outlet 14. When compressed air is supplied from the air compressor 5 to the bifluid nozzle 3, the compressed air is ejected from the compressed air outlet 16 through the compressed air passage 15 between the inner pipe 11 and the outer pipe 12. Then, the liquid passage 13 is depressurized by the flow of the compressed air from the compressed air ejection port 16, and the liquid stored in the liquid storage unit 4 is sucked into the liquid passage 13. As a result, the liquid is sucked from the liquid storage unit 4 by the flow of the compressed air, and the liquid is sprayed together with the compressed air from the bifluid nozzle 3. The liquid and the compressed air are configured to be mixed outside the nozzle, and if the two-fluid nozzle 3 is configured in this way, the liquid ejected from the liquid ejection port 14 is mixed with the compressed air ejected from the outer periphery thereof. The ejected liquid is easily atomized by the shearing action of compressed air. As a result, it becomes possible to spray the liquid with droplets having a smaller particle size.

The two fluid nozzles 3 are formed so that the liquid outlet 14 projects from the compressed air outlet 16, the inner diameter of the compressed air outlet 16 is D, and the protrusion length of the liquid outlet 14 from the compressed air outlet 16. When the gap between L and the inner tube 11 and the outer tube 12 is C, the L / D value is 0.45 or less, and the L / C value is 6.0 or less. By configuring the tip of the bifluid nozzle 3 in this way, the amount of liquid sprayed from the bifluid nozzle 3 can be increased monotonically by increasing the pressure of the compressed air. In other words, when the L / D value is larger than 0.45 or the L / C value is larger than 6.0, the relationship between the pressure of the compressed air and the spray amount does not become a monotonous increase relationship. , Partial reversal may occur. Therefore, the amount of spray is adjusted by adjusting the compressed air pressure by configuring the tip of the bifluid nozzle 3 so that the L / D value is 0.45 or less and the L / C value is 6.0 or less. Can be easily changed arbitrarily. In addition, the spray amount can be controlled in a wide range of compressed air pressure, and the spray amount can be significantly changed.

The gap C between the inner pipe 11 and the outer pipe 12 is the outer surface and the outer surface of the inner pipe 11 at the axial position where the gap is the narrowest when the tip of the bifluid nozzle 3 is viewed in the axial cross section. It means the distance between the inner surfaces of the pipe 12. If the gap between the inner pipe 11 and the outer pipe 12 is not constant when the tip of the bifluid nozzle 3 is viewed in a vertical cross section in the axial direction, the gap between the inner pipe 11 and the outer pipe 12 is the widest. The distance between the outer surface of the inner pipe 11 and the inner surface of the outer pipe 12 is measured at the location, and this is defined as the gap spacing C.

In Tables 1 and 2, for the two-fluid nozzle 3 shown in FIG. 2, the sizes of the inner tube 11 and the outer tube 12 are changed, and the protruding length of the inner tube 11 from the tip of the outer tube 12 is changed. The result of investigating the relationship between the compressed air pressure supplied to the bifluid nozzle 3 and the amount of liquid spray from the bifluid nozzle 3 is shown. For each of the two fluid nozzles 3, the compressed air pressure was changed from 0.05 MPa to 0.50 MPa in increments of 0.05 MPa, the spray amount at each pressure was measured, and the horizontal axis was the compressed air pressure and the vertical axis was the spray amount. The measurement results were plotted. For the plotted measurement results, check whether the relationship between the compressed air pressure and the spray amount is monotonically increasing, and if so, approximate the plotted measurement results with a linear or quadratic function. Then, the determination coefficient ^R2 representing the degree of approximation at that time was obtained, and the results are shown in Table 2. Table 2 also shows the spray amount ratio when the compressed air pressure was 0.40 MPa and when the compressed air pressure was 0.10 MPa.

As can be seen from the results shown in Tables 1 and 2 above, No. Nozzle 1 had an L / D value of more than 0.45, and No. 1 was used. 6 and No. The L / C value of 11 nozzles is larger than 6.0, and when these nozzles are used, the relationship between the compressed air pressure P and the spray amount Q does not become a monotonous increase relationship, and in some cases, compression is performed. It was found that the higher the air pressure P, the lower the spray amount Q. On the other hand, other No. For nozzles 2 to 5, 7 to 10, 12 to 15, the L / D value is 0.45 or less and the L / C value is 6.0 or less, and the relationship between the compressed air pressure P and the spray amount Q is monotonous. It became a relationship of increase. When these nozzles are used, the relationship between the compressed air pressure P and the spray amount Q can be accurately approximated by a quadratic function, and the quadratic function increases monotonically in the range where the compressed air pressure P is 0.50 MPa or less. And the shape is convex upward (that is, the first derivative is monotonically decreased). Therefore, when these nozzles are used, the spray amount Q is arbitrarily adjusted by adjusting the opening degree of the proportional control valve 7 and changing the compressed air pressure P based on the quadratic function thus obtained. Will be easier.

It is preferable that the spray amount Q has a linear relationship with the compressed air pressure P as much as possible, that is, it is preferable that the slope of the approximate quadratic function does not change as much as possible regardless of whether the compressed air pressure P is high or low. .. As a result, it becomes easy to adjust the spray amount Q by adjusting the opening degree of the proportional control valve 7 to change the compressed air pressure P in the same manner when the compressed air pressure P is high or low. In other words, if the approximated quadratic function has a large upward convex shape, when the compressed air pressure P is low, the spray amount Q will change significantly even if the compressed air pressure P is slightly changed. When the compressed air pressure P is high, the spray amount Q does not change much even if the compressed air pressure P is changed. Therefore, it may be difficult to adjust the spray amount Q depending on the magnitude of the compressed air pressure P.

From the above viewpoint, the L / C value is preferably 1.2 or more and 5.5 or less. By setting the relationship between the protrusion length L of the liquid outlet 14 from the compressed air outlet 16 and the gap distance C between the inner tube 11 and the outer tube 12 in this way, the compressed air when the liquid is sprayed from the nozzle is set in this way. The relationship between the pressure P and the spray amount Q can be accurately approximated by a linear function. Looking at Tables 1 and 2, No. 5 and No. Nozzle No. 12 has an L / C value smaller than 1.2 or larger than 5.5. Nozzles 2 to 4, 7 to 10, 13 to 15 have an L / C value of 1.2 or more and 5.5 or less, and No. It was possible to more accurately approximate the linear function of the relationship between the compressed air pressure P and the spray amount Q by using the nozzles of 2 to 4, 7 to 10, 13 to 15.

Since the tip of the two-fluid nozzle 3 is configured as described above, the spray amount Q can be controlled in a wide range of the compressed air pressure P, and the spray amount Q can be significantly changed. .. For example, as shown in Table 2, the ratio of the spray amount Q when the compressed air pressure is 0.40 MPa and the spray amount Q when the compressed air pressure is 0.10 MPa can be set to about 2.0 times, which is Patent Document 1. Compared with the result disclosed in FIG. 3, the spray amount ratio is very large. As described above, the bifluid nozzle 3 is preferably capable of spraying at both the compressed air pressure P of 0.40 MPa and 0.10 MPa, and the spray amount Q when the compressed air pressure P is 0.40 MPa. The ratio of the spray amount Q at 0.10 MPa is preferably 1.5 times or more, more preferably 1.6 times or more, still more preferably 1.8 times or more. As will be described later, when the compressed air passage 15 is partially closed when viewed from the compressed air outlet 16 side, the spray amount Q can be changed more significantly by changing the compressed air pressure P. .. In this case, the ratio of the spray amount Q when the compressed air pressure P is 0.40 MPa and the spray amount Q when the compressed air pressure P is 0.10 MPa can be further increased. For example, the ratio can be increased by 3.0 times or more. It can be 0 times or more or 5.0 times or more. On the other hand, the upper limit of the ratio of the spray amount Q when the compressed air pressure P is 0.40 MPa and the spray amount Q when 0.10 MPa is not particularly limited, but may be 12.0 times or less, for example, 10 It may be 0.0 times or less.

The bifluid nozzle 3 is not limited to the shape and size shown in FIG. 2 and Table 1, and can be appropriately set. For example, the inner diameter of the inner pipe 11 or the inner diameter of the liquid ejection port 14 is preferably 0.1 mm or more, more preferably 0.2 mm or more, preferably 1.5 mm or less, and more preferably 1.0 mm or less. The inner diameter D of the outer pipe 12 or the compressed air outlet 16 is preferably 0.3 mm or more, more preferably 0.5 mm or more, more preferably 3.0 mm or less, and even more preferably 2.5 mm or less. The wall thickness of the inner pipe 11 in the liquid outlet 14 (that is, the value obtained by dividing the difference between the inner diameter and the outer diameter of the liquid outlet 14 by 2) is preferably 0.05 mm or more, more preferably 0.1 mm or more, and 1 It is preferably 0.0 mm or less, and more preferably 0.8 mm or less. The gap C between the inner tube 11 and the outer tube 12 is preferably 0.03 mm or more, more preferably 0.05 mm or more, more preferably 0.5 mm or less, and even more preferably 0.3 mm or less. The ratio of the inner diameter of the outer pipe 12 to the inner diameter of the inner pipe 11 or the ratio of the inner diameter of the compressed air outlet 16 to the inner diameter of the liquid outlet 14 is preferably 1.2 or more, more preferably 1.5 or more, and 5. 0 or less is preferable, and 3.0 or less is more preferable. The ratio of the inner diameter of the inner pipe 11 / the gap gap C or the ratio of the inner diameter / gap gap C of the liquid ejection port 14 is preferably 1.5 or more, more preferably 2.0 or more, and preferably 10.0 or less, 8 It is more preferably 0.0 or less, and even more preferably 5.5 or less. The protrusion length L of the liquid outlet 14 from the compressed air outlet 16 is preferably 0.05 mm or more, more preferably 0.1 mm or more, preferably 1.5 mm or less, and more preferably 1.2 mm or less. It is more preferably 0.0 mm or less. The liquid outlet 14 and the compressed air outlet 16 are preferably formed so as to have end faces perpendicular to the axial direction.

It is preferable that the tip portion of the two-fluid nozzle 3 has a portion having a gap interval C satisfying the above L / C ≦ 6.0 having a certain length in the axial direction. For example, the tip of the two-fluid nozzle 3 has an axial length of a portion having a gap spacing C of 1.5 times or more the protrusion length L from the compressed air outlet 16 of the liquid outlet 14. Is preferable, 2.0 times or more is more preferable, 10.0 times or less is preferable, and 8.0 times or less is more preferable. As described above, the gap C between the inner pipe 11 and the outer pipe 12 is the inner pipe 11 at the axial position where the gap is the narrowest when the tip of the bifluid nozzle 3 is viewed in the axial cross section. Since it means the distance between the outer surface of the outer tube and the inner surface of the outer tube 12, when the portion having the gap spacing C is formed with a certain length in the axial direction, the inner tube 11 and the outer tube 12 are formed with respect to the axial direction. The gap spacing is formed to be constant within a predetermined length range.

At the tip of the two fluid nozzles 3, the portion having the gap spacing C is preferably formed at least in or near the compressed air outlet 16, for example, from the compressed air outlet 16 to the outer diameter of the liquid outlet 14. It is preferable that the liquid is formed at least in a portion inward by a corresponding length (more preferably, a portion inward by a length corresponding to half of the outer diameter of the liquid outlet 14 from the compressed air outlet 16). From there, it is preferable that the compressed air outlet 16 is formed in the direction opposite to the compressed air outlet 16 in a certain length. The portion having the gap spacing C may be formed with a certain length in the axial direction from the compressed air outlet 16 as a starting point.

The tip end portion of the inner tube 11 may be formed in a tapered shape. For example, the outer surface of the tip end portion of the inner pipe 11 may be formed so as to be inclined toward the central axis toward the compressed air outlet 16. Since the tip portion of the inner pipe 11 is formed in this way, the liquid passage 13 is likely to be effectively depressurized by the flow of compressed air from the compressed air outlet 16. Further, the liquid ejected from the liquid outlet 14 is more likely to be sheared more finely by the compressed air ejected from the compressed air outlet 16, and further atomization can be achieved.

It is preferable that the inner diameter of the tip portion of the inner pipe 11 is formed to be constant with a certain length on the side opposite to the liquid outlet 14 in the axial direction, starting from the liquid outlet 14 or its vicinity. For example, the inner diameter of the tip of the inner pipe 11 is preferably formed to be constant over an axial length range of 3 times or more the length corresponding to the inner diameter of the liquid ejection port 14, and 4 times or more is more preferable. It is preferable, and more preferably 5 times or more. Further, it is preferable that the portion where the inner diameter of the inner pipe 11 is constant is formed at least in the portion which is inward from the liquid outlet 14 by the length corresponding to the inner diameter of the liquid outlet 14. By forming the tip portion of the inner pipe 11 in this way, the liquid stored in the liquid storage portion 4 can be suitably sucked up to the liquid ejection port 14 due to the flow of the compressed air.

The space between the inner pipe 11 and the outer pipe 12, that is, the compressed air passage 15, may be partially closed when viewed from the compressed air outlet 16 side. FIG. 3 shows a configuration example when the two-fluid nozzle 3 is viewed from the tip side (compressed air ejection port 16 side). FIG. 3A shows a view of the two-fluid nozzle 3 shown in FIG. 2 as viewed from the tip side, and the space between the inner pipe 11 and the outer pipe 12 is viewed from the compressed air outlet 16 side. Is not blocked. On the other hand, FIGS. 3 (b) to 3 (d) show an example in which the space between the inner pipe 11 and the outer pipe 12 is partially closed when viewed from the compressed air outlet 16 side. In this way, the space between the inner pipe 11 and the outer pipe 12 is partially closed when viewed from the compressed air outlet 16 side, so that the gap C between the inner pipe 11 and the outer pipe 12 is secured. While doing so, the cross-sectional area of the compressed air passage 15 (cross-sectional area perpendicular to the axial direction) can be narrowed. Therefore, the flow velocity of the compressed air ejected from the compressed air outlet 16 can be increased, and the amount of liquid sprayed from the liquid outlet 14 can be stably increased. Further, the spray amount Q can be changed more greatly by changing the compressed air pressure P.

As a mode of partially closing the space between the inner pipe 11 and the outer pipe 12, a part of the outer surface of the inner pipe 11 is projected outward, and a part of the inner surface of the outer pipe 12 is inward. Examples thereof include a mode in which the spacer member is arranged between the outer surface of the inner pipe 11 and the inner surface of the outer pipe 12. The portion where the space between the inner pipe 11 and the outer pipe 12 is partially closed is preferably formed to have a certain length in the axial direction, for example, a length corresponding to the inner diameter of the compressed air outlet 16. It is preferably formed to be constant over an axial length range of 0.3 times or more, more preferably 0.5 times or more, still more preferably 0.8 times or more. The upper limit of the axial length of the portion where the space between the inner pipe 11 and the outer pipe 12 is partially closed is not particularly limited, and is, for example, 5.0 times the length corresponding to the inner diameter of the compressed air outlet 16. Hereinafter, it may be 3.0 times or less, or 2.5 times or less.

The average particle size of the liquid sprayed from the two-fluid nozzle 3 is preferably, for example, 50 μm or less, more preferably 30 μm or less, still more preferably 10 μm or less. The lower limit of the average particle size of the sprayed liquid is not particularly limited, and may be 1 μm or more, 3 μm or more, or 5 μm or more. The liquid may be sprayed as a dry fog, that is, it may be sprayed into a fine mist that does not feel wet when touched. By spraying the liquid as a dry fog having an average particle diameter of, for example, 10 μm or less, the liquid can be evenly distributed in the target space in a short time without wetting the spray target space. The average particle size described here is when the particle size distribution of the droplet is measured at a point 30 cm away from the tip of the nozzle using a laser diffraction type particle size distribution measuring device for the liquid sprayed from the nozzle. Means the average particle size of Sauter.

The spraying device of the present invention can be used for various purposes such as humidification, cooling, static electricity prevention, air cleaning, sterilization cleaning, and infection prevention. The spray target space may be an outdoor space, an indoor space surrounded by a wall or a roof, or a semi-indoor space having no roof or a part of the wall and allowing outside air to freely enter and exit. Examples of the indoor spray target space include factories, clean rooms, warehouses, halls, offices, factories, hospitals, nursing homes, stores, schools, houses, barns, greenhouses, plant factories, mushroom cultivation rooms, and the like.

1: Spraying device 2: Spraying unit 3: Two-fluid nozzle 4: Liquid storage unit 5: Air compressor 6: Compressed air supply path 7: Proportional control valve 8: Liquid supply path 9: Control unit 10: Humidity measuring means 11: Inside Pipe 12: Outer pipe 13: Liquid passage 14: Liquid outlet 15: Compressed air passage 16: Compressed air outlet

Claims (3)

With a two-fluid nozzle,
A liquid storage unit in which the liquid sprayed from the two fluid nozzles is stored, and
An air compressor that supplies compressed air to the two-fluid nozzle,
A compressed air supply path that communicates with the two-fluid nozzle and the air compressor and allows compressed air from the air compressor to pass through.
A spraying device having a proportional control valve provided in the compressed air supply path.
The tip of the two-fluid nozzle has a double-tube structure having an inner tube and an outer tube, a liquid ejection port is formed at the tip of the inner tube, and a compressed air ejection port is formed at the tip of the outer tube. The liquid outlet is formed so as to protrude from the compressed air outlet, the liquid is sucked from the liquid storage portion by the flow of the compressed air from the compressed air outlet, and the liquid is sprayed together with the compressed air from the liquid outlet. Being done
When the inner diameter of the compressed air outlet is D, the protrusion length of the liquid outlet from the compressed air outlet is L, and the gap between the inner pipe and the outer pipe is C, the value of L / D is A spraying device having a value of 0.45 or less and an L / C value of 6.0 or less. The spraying device according to claim 1, wherein the L / C value is 1.2 or more and 5.5 or less. The spray device according to claim 1 or 2, wherein the space between the inner pipe and the outer pipe at the tip of the two-fluid nozzle is partially closed when viewed from the compressed air outlet side.

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