JPH06238211A - Spray device and method - Google Patents

Abstract

PURPOSE: To impinge a supersonic gaseous stream as a shock wave upon a liquid stream and to efficiently atomize the liquid by generating the supersonic gaseous stream near the outlet of the liquid stream. CONSTITUTION: An ejection hole 32 of a housing 10 and a supersonic flow area regulated by the hole and the tapered end 54 of a liquid flowpath forming member 34 are disposed near the tapered end 54 of the liquid flowpath forming member 34, and the liquid is atomized by acting the gaseous stream generated in the supersonic flow area as the shock wave on the liquid stream flowing out of the tapered end 54. The gaseous stream is preferably made into a helical stream by disposing a subsonic flow area of a tapered cylindrical shape regulated by the second tapered part 30 of the housing 10 and the tapered end 54 of the liquid flowpath forming member 34 upstream of the supersonic flow area and further disposing a helical path upstream thereof.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a spraying device and a spraying method.

[0002]

A large number of atomizers are known. For example, US Pat. No. 3,908,903,
No. 3,980,233, No. 4,335,677, No. 4,341,530, No. 4,406,404, No. 4,595,143, No. 4,773,596, No. 4, , 834,343, 4,943,704, 4,946,101, 5,044,559, 5,059,357, 5,181,661, etc. of the present invention. Can be considered prior art. In the slurry atomizer disclosed in the above-mentioned US Pat. No. 4,341,530,
A liquid passage is provided in the axial direction of the spraying device, and a pressurized vapor flow is spirally sent around the axis. Then, the spiral vapor flow collides with the liquid passage to draw the liquid from the liquid passage, and the resulting axial liquid flow is scattered to form mist-like droplets.

[0003]

An object of the present invention is to provide a novel spraying device and spraying method. In particular, an object of the present invention is to provide a spraying device and a spraying method for efficiently atomizing a liquid by causing a supersonic gas flow near the outlet of the liquid to cause the gas flow to collide with the liquid flow as a shock wave. Is to provide.

[0004]

Means for Solving the Problems In order to solve the above problems, a spraying device according to the present invention comprises a liquid inlet, a gas inlet for receiving a pressurized gas, a liquid passage extending from the liquid inlet to the liquid outlet, and a gas. A shock wave that extends while curving from the inlet to the vicinity of the liquid outlet, and includes a curved gas flow passage including a supersonic flow region near the liquid outlet, and the supersonic gas flow near the liquid outlet collides with the liquid flow flowing out from the liquid outlet. And is configured to atomize the liquid stream.

The curved gas passage preferably includes a spiral passage, and the spiral passage is preferably provided around the liquid passage. It is preferable that the curved gas passage further includes a frustoconical subsonic flow region adjacent to the upstream side of the supersonic flow region. Further, it is desirable that the liquid passage extends in the axial direction of the spraying device.

Further, the spraying method according to the present invention includes the steps of providing a liquid passage extending from the liquid inlet to the liquid outlet, producing a flow of pressurized gas from the gas inlet through the curved gas passage, and the pressurized gas. Is a supersonic gas flow in the supersonic flow region near the liquid outlet, and a shock wave that collides with the liquid flow flowing out from the liquid outlet is generated to atomize the liquid flow.

The flow of the pressurized gas preferably passes through a spiral passage, the spiral passage is preferably provided around the liquid passage, and the liquid passage may extend in the axial direction of the spraying device. desirable. The pressurized gas is
It is desirable to pass through a frustoconical subsonic flow region adjacent to the upstream side of the supersonic flow region. Further, it is desirable that the liquid flow is generated by suction by the flow of the pressurized gas.

[0008]

In the spraying device and spraying method according to the present invention, the gas flow becomes a supersonic gas flow in the supersonic flow region provided near the outlet of the liquid passage, and acts as a shock wave on the liquid flow flowing out from the liquid outlet. By doing so, the liquid is efficiently atomized.

In the preferred embodiment where the curved gas passages include spiral passages, the gas flow is a spiral flow that effectively acts on the liquid flow to promote atomization. In particular, when the spiral passage is provided around the liquid passage, the spiral flow of gas swirls around the columnar liquid flow to disturb the liquid flow, and as a result, the liquid that has flown outward from the liquid flow. The gas stream impinges on the droplets and disperses them into smaller droplets. When the curved gas passage includes a frustoconical subsonic flow region adjacent to the upstream side of the supersonic flow region, the supersonic gas flow has a velocity component in the direction intersecting with the liquid flow, and the liquid flow The effect of the shock wave on the is further effectively generated to promote atomization. When the liquid passage extends in the axial direction of the spraying device, it is easy to form not only the liquid passage itself but also the gas passage, and
It means that the spraying is performed in the axial direction of the spraying device.

[0010]

In the spraying device and spraying method according to the present invention, the shock wave of the supersonic gas flow acts on the liquid flow to atomize it, so that the spraying can be performed efficiently. In particular,
In a desirable embodiment where the gas passage includes a spiral passage, a further desirable embodiment where the spiral passage is formed around the liquid passage, or a desirable embodiment where the gas passage includes a frustoconical subsonic flow region, the atomization is performed. It can be performed more efficiently.

Further, in a desirable mode in which the liquid passage extends in the axial direction of the spraying device, the effect of facilitating the manufacture of the device is obtained. Further, in the preferred embodiment where the flow of liquid is produced by suction with a flow of pressurized gas,
It does not require a device to pressurize the liquid, and the effect of simplifying the structure of the device is obtained, and if the specifications of the spraying device are properly determined, even if the flow rate of the gas changes a little, the liquid Since the flow rate of is also changed, the effect that atomization is always performed in the optimum state can be obtained.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 5 show a spraying device which is an embodiment of the present invention and which is also a device for carrying out a spraying method as an embodiment of the present invention.

The spraying device comprises a housing 10, which has an opening 12 for pressurized gas and an opening 14 for liquid. A female screw is cut in the opening 12 for pressurized gas,
A pressurized gas supply joint device 16 having a male screw corresponding to the female screw is airtightly screwed. This joint device 16
Therefore, a pressurized gas such as air pressurized in the range of 5.5 to 6.5 atm is supplied into the housing 10. However,
The structure of the pressurized gas supply unit can be changed to other modes.

The liquid opening 14 communicates with the multi-stage axial hole 18, and the multi-stage axial hole 18 communicates with the pressurized gas opening 12. As shown in FIG. 3, the multi-stage axial hole 18 includes a female threaded portion 20 adjacent to the liquid opening 14 and a first intermediate narrowed portion 22 that follows the female threaded portion 20. First intermediate narrow portion 22
Following this, there is a further narrow second intermediate narrow portion 24, which leads to the pressurized gas opening 12 in this second intermediate narrow portion 24. The second intermediate narrow portion 24 continues to the first tapered portion 26, and the first tapered portion 26 is narrower than the third intermediate narrow portion 2.
It continues to 8. There is a second tapered portion 30 following the third intermediate narrow portion 28, and the second tapered portion 30 continues to the ejection hole 32 extending in the axial direction.

The liquid passage forming member 34 includes a multi-stage axial hole 18
Is screwed onto. In the screwed state, the liquid passage forming member 34
The liquid inlet portion 38 of is adjacent to the liquid opening 14. As shown in FIG. 3, the liquid passage forming member 34 has a liquid inlet portion 38.
In addition to this, it has a male screw portion 40. The male screw portion 40 is screwed into the female screw portion 20 of the multi-stage axial hole 18. The male screw portion 40 continues to the first medium diameter 42. A notch 44 is formed in the first medium diameter portion 42, and a seal ring 46 is housed in the notch 44. The first medium diameter portion 42 continues to a thinner second medium diameter portion 48, and the second medium diameter portion 48 continues to a spiral passage defining portion 50 in which a spiral groove is formed. The spiral passage defining portion 50 faces the opening 12 for pressurized gas. The spiral passage defining portion 50 has a tapered portion 52 that gradually becomes thinner.
Then, the tapered portion 52 passes through the small diameter portion 53 and then to the tapered end portion 54 which becomes sharply thin, and this is the end of the liquid passage forming member 34.

A liquid passage forming member 34 is formed in the multi-stage axial hole 18.
In the state in which is screwed, a gas passage is formed between the housing 10 and the liquid passage forming member 34 with the pressurized gas opening 12 as an inlet and the ejection hole 32 as an outlet. 2 to 5, the gas passage includes a spiral passage defined by the second intermediate narrow portion 24 and the spiral passage defining portion 50 (FIG. 3), and the tip of the spiral passage is formed. In addition, the first tapered passage having a tapered cylindrical shape or a truncated cone shape in which the first tapered portion 26 and the tapered portion 52 (FIG. 3) gradually reduce the cross-sectional area and the diameter gradually decrease toward the distal end side. It is formed. Further, further ahead, a cylindrical passage is formed by the third intermediate narrow portion 28 and the small diameter portion 53 (FIG. 5), and the cylindrical passage has a diameter that is gradually and gradually reduced from that of the first tapered passage. Continuing to the tapered passage (30, 54), this second tapered passage is a straight jet hole 32.
The state continues to. The flow of the pressurized gas accelerated in the first tapered passage is the second tapered passage (30, 54).
Is further accelerated and is ejected to the ejection hole 32.

As is apparent from FIG. 5, the sharply tapered end portion 54 of the liquid passage forming member 34 and the second tapered portion 30 of the housing 10 and the straight ejection hole 32.
An area expansion portion is formed between the tapered end portion 54 and the inner surface of the ejection hole 32, in which the cross-sectional area of the gas passage sharply increases. The boundary between the second tapered portion 30 and the straight ejection hole 32 defines the neck portion having the narrowest cross-sectional area, and the flow velocity of the pressurized gas is the neck portion (if the contraction is taken into consideration, the neck portion has It becomes maximum on the slightly downstream side, that is, within the area expansion part. The gas passage whose cross-sectional area has gradually decreased in this manner turns to increase at the neck portion as a boundary, so that the portion where the flow velocity of the pressurized gas becomes maximum is accurately defined, and the position thereof is the tip of the liquid passage forming member 34 ( That is, it is guaranteed to be slightly before the outlet of the liquid passage formed therein.

Opening 1 for pressurized gas as inlet of gas passage
As shown in FIG. 1, a pressure control valve 82 and a pressurized gas supply device 84 are connected to 2 via a joint device 16, and the pressure of the pressurized gas supplied to the pressurized gas opening 12 is increased. Is adjusted by the gas pressure control valve 82 to generate a supersonic flow of gas at the neck portion. The boundary portion between the second tapered portion 30 and the ejection hole 32 defines the boundary between the subsonic gas flow region and the sonic gas flow region shown by the line of Mach 1 in FIG.

On the other hand, the liquid flows from the liquid inlet 60 having an internal thread to be screwed into the liquid supply joint device 62 into the gradually narrowing liquid passage 58 of the liquid passage forming member 34, and the neck portion is formed. Reach the exit a little further ahead. At that time, due to the tangential component (axial component) of the gas flow in contact with the liquid flow, even if pressure is not applied,
The liquid stream is drawn from the liquid supply source 86 shown in FIG. 1 through the liquid passage 58. The liquid spreads in the ejection holes 32 to form droplets 70. The core of this liquid flow is shown by broken line 7
Indicated by 2. The supersonic gas flow generated in the region between the tapered end portion 54 of the liquid passage forming member 34 and the ejection hole 32 of the housing 10 obliquely collides with the liquid flow as a shock wave 74 to atomize the liquid. Tapered line 76
Indicates the boundary between the gas flow and the liquid flow, and the short line 78 indicates the recirculating effect of both flows.
s). The aerosol 80 thus formed spreads in a tapered shape as shown in FIG.
Eject from 2.

As is clear from the above description, the liquid is drawn out as a result of the substantially tangential (axial direction) gas flow creating a high vacuum state, and the gas is brought into contact with the liquid at supersonic speed to be atomized. Is one of the features of this embodiment.
It is believed that the relatively high vacuum conditions achieved by the present invention significantly increase the efficiency of liquid atomization, especially due to the high level of evaporation thereby produced.

The results actually obtained by using the above-mentioned spraying device shown in FIGS. 1 to 5 are listed below. Gas flow rate: 50-60 liters / minute (1.76-2.1)
2cfm) Gas inlet pressure: 6 bar (Bar) Liquid flow rate: 5.5-6 liters / hour Jetted droplet size (average value): 2-10 microns Vacuum level: 6-7m Water column (WG) Evaporation: About water 10%

Those skilled in the art will readily understand that the present invention is in no way limited to the above specific description.

[Brief description of drawings]

FIG. 1 is a perspective view showing a spraying device which is an embodiment of the invention of claim 1 and is also a device for carrying out a spraying method as an embodiment of the invention of claim 6;

2 is a sectional view taken along line II-II of the spraying device of FIG.

FIG. 3 is a sectional view corresponding to FIG. 2, showing the spraying device of FIG. 1 in an exploded manner.

FIG. 4 is a cross-sectional view corresponding to FIGS. 2 and 3, showing an enlarged main part of the spraying device of FIG. 1.

5 is an enlarged view of the main part of the spraying device of FIG. 1,
It is sectional drawing corresponding to FIG. 2 and FIG.

[Explanation of symbols]

 12 Opening for Pressurized Gas 14 Opening for Liquid 30 Second Tapered Portion 32 Ejection Hole 34 Liquid Passage Forming Member 50 Spiral Passage Defining Part 54 Tapered End 58 Liquid Passage

Claims (10)

[Claims] 1. A liquid inlet, a gas inlet for receiving a pressurized gas, a liquid passage extending from the liquid inlet to the liquid outlet, a curved passage extending from the gas inlet to the vicinity of the liquid outlet,
A shock gas generated by a supersonic gas flow in the vicinity of the liquid outlet includes a curved gas flow passage including a supersonic flow region near the liquid outlet, collides with a liquid flow flowing out from the liquid outlet, and atomizes the liquid flow. A spraying device, which promotes 2. The atomizing device of claim 1, wherein the curved gas passage comprises a spiral passage. 3. The spraying device according to claim 2, wherein the spiral passage is provided around the liquid passage. 4. The spray device according to claim 1, wherein the liquid passage extends in the axial direction of the spray device. 5. The spraying device according to claim 2, wherein the curved gas passage includes a frustoconical subsonic flow region adjacent to the upstream side of the supersonic flow region. 6. A step of providing a liquid passage extending from a liquid inlet to a liquid outlet, a step of generating a flow of a pressurized gas from a gas inlet through a curved gas passage, and a flow of the pressurized gas in the vicinity of the liquid outlet. A spraying method, comprising: forming a supersonic gas flow in a supersonic flow region, generating a shock wave that collides with a liquid flow flowing out from the liquid outlet, and atomizing the liquid flow. 7. A spraying method according to claim 6, wherein the flow of the pressurized gas passes through a spiral passage. 8. A spraying method according to claim 7, wherein the spiral passage is provided around the liquid passage, and the liquid passage is preferably provided in the axial direction of the spraying device. 9. The pressurized gas passes through a frustoconical subsonic flow region adjacent to the upstream side of the supersonic flow region.
Or the spraying method of 8. 10. The spraying method according to claim 7, wherein the flow of the liquid is generated by suction by the flow of the pressurized gas.