JP2019115901A - Two-fluid nozzle - Google Patents

Abstract

To provide a two-fluid nozzle which has a charging prevention effect and hardly incorporates foreign matter.SOLUTION: A two-fluid nozzle includes a gas supply port 41 through which compressed gas is introduced, a liquid supply port 31, an ejection port 70 through which mixed fluid of gas and liquid is ejected, and a main body part 10 which communicates between the gas supply port 41 and the ejection port 70 and partitions a channel 60 to which the liquid supply port 31 is opened within an inner part. Therein, the channel 60 has at least one of a convergent part 61 of which the diameter is contracted from the gas supply port 41 and a divergent part of which the diameter is expanded toward the ejection port and a throat part 62 as a part in which a pressure on an inner part becomes higher between the gas supply port 41 and the ejection port 70, and a prescribed range of the downstream side from the throat part 62 and of the downstream side from the liquid supply port 31, of the main body part 10 is formed with a fluororesin material and an electroconductive fluororesin material containing carbon nanotubes which are dispersed in the fluororesin material in concentration of 0.010 to 0.060% based on the whole of mass.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a two-fluid nozzle capable of dispersing and spraying a liquid in a gas.

  A two-fluid nozzle is conventionally known which atomizes a liquid by the flow of air or the like and sprays it, for example, a nozzle body provided with a divergent portion which expands in the flow direction downstream of the throat portion having a circular cross section; A cleaning nozzle having a cleaning solution supply pipe for discharging a cleaning solution in the same direction as the flow of compressed air supplied to the nozzle body, wherein the discharge port of the cleaning solution supply pipe is in the vicinity of the throat portion away from the inner wall surface of the nozzle body Patent Document 1 discloses a technology in which the compressed gas is at the speed of sound at the throat portion.

  The two-fluid nozzle can be used to refine the liquid, and when used in a cleaning device or the like, the damage to the object to be cleaned is not a problem, and the application to various applications is made (for example, patent documents 2, 3 etc.).

  By the way, in the two-fluid nozzle disclosed in Patent Documents 1 to 3, friction occurs between the flow path of the fluid and the fluid in order to flow the fluid at a high speed, and the generation of charging of the fluid is a problem. When charging occurs, various problems will occur. For example, in the case of employing for cleaning the semiconductor device, there is an adverse effect on the semiconductor device due to charging.

  In order to solve this problem, it is conceivable to form the flow path of the fluid from metal or conductive resin material, but the friction between the fluid flowing at a high speed and the flow path mixes metal or conductive resin material into the fluid In some cases, it has been difficult to apply to applications where the amount of conductive impurities present is severely limited, such as semiconductor manufacturing applications.

  By the way, although it is not a two-fluid nozzle, the technique which comprises the main-body part which a liquid flows in a fluid apparatus which makes a liquid object is comprised with electroconductive fluoro resin material is disclosed (patent document 4). Patent Document 4 discloses that charging can be effectively suppressed by containing carbon nanotubes in a proportion of 0.020% by weight or more and 0.030% by weight in a fluorine resin. In Patent Document 4, there is an upper limit to the content of carbon nanotubes, because it is a minute proportion of 0.030% by weight or less of the proportion of carbon nanotubes contained in the conductive fluororesin material in 0009 paragraph of Patent Document 4 ... Contamination by carbon nanotubes released by addition in a proportion of more than 0.030% by weight, as described as "can suppress contamination of fluid by contact between fluid flow path and fluid." Was a concern.

JP 2007-073615 A JP, 2008-307624, A JP, 2009-154146, A Unexamined-Japanese-Patent No. 2017-75696

  The present inventors examined whether charging can be suppressed by adopting the conductive fluororesin material disclosed in Patent Document 4 also for the two-fluid nozzle. As a result, it was found that the conductive fluororesin material disclosed in Patent Document 4 can not exhibit a sufficient antistatic effect.

  The present invention has been completed in view of the above situation, and it is an object of the present invention to provide a two-fluid nozzle which has a sufficient antistatic effect and is less contaminated with foreign substances such as carbon nanotubes.

  As a result of intensive investigations by the present inventors for the purpose of solving the above-mentioned problems, in the case of a two-fluid nozzle, when the main body portion is made of a conductive fluorocarbon resin material, It has been found that the behavior is different from when adopting.

  Specifically, in the two-fluid nozzle, even if the amount of carbon nanotubes to be contained in the conductive fluorocarbon resin is increased as compared with the case where only liquid is employed as the fluid as in Patent Document 4, the influence of carbon nanotube mixing is suppressed I found that I could do it.

  As a result, in the two-fluid nozzle, the amount of carbon nanotubes contained in the conductive fluorocarbon resin can be increased more than in Patent Document 4 to improve the conductivity, and therefore the antistatic effect can be improved.

  Furthermore, since it is a two-fluid nozzle that targets two fluids of gas and liquid, the generation of static electricity is suppressed, so a sufficient antistatic effect may be exhibited even when the content of carbon nanotubes is reduced. I understood it.

  Details will be described below.

  When the pressure of the mixed fluid of gas and liquid flowing in the flow path is high, the friction between the mixed fluid and the inner wall of the flow path becomes large, and charging of the mixed fluid becomes a problem. By comprising the conductive fluororesin material, charging of the mixed fluid can be effectively suppressed.

  Here, the conductive fluorocarbon resin material is desorbed from the contained carbon nanotubes by friction with the mixed fluid. Up to this point, the action mechanism is the same as that of the fluid device of Patent Document 4, but in the two-fluid nozzle, carbon nanotubes released due to the fact that the flowing fluid is a mixed fluid of gas and liquid are covered The impact on the processed material is reduced.

  The carbon nanotubes detached when the mixed fluid jetted from the two-fluid nozzle jets toward the object to be treated are mixed not only in the liquid in the mixed fluid but also in the gas, so the liquid portion in the jetted mixed fluid The amount of carbon nanotubes contained in is reduced by the amount of carbon nanotubes contained in the gas portion.

  The mixed fluid expands the gas portion due to the subsequent pressure drop, so the portion of the desorbed carbon nanotube contained in the gas portion decreases in concentration as it expands. As a result, the influence on the object to be treated is reduced. Therefore, the presence of the gas reduces the influence of the desorbed carbon nanotubes on the object to be treated.

  Carbon nanotubes, which are also contained in the gas part of the mixed fluid at the beginning of desorption, may be considered to be transferred to the liquid part thereafter, but in the two-fluid nozzle, they expand rapidly before being ejected, but the unit volume Since the contact area with the liquid does not change, it becomes difficult for the carbon nanotubes contained in the gas part to transfer to the liquid part, and eventually the content is reduced due to expansion while being contained in the gas part.

  Therefore, in a two-fluid nozzle that uses a compressed gas at high pressure as a fluid, carbon nanotubes mixed at high pressure are reduced in concentration and then reduced in concentration when the carbon nanotube is expanded and then expanded. It was possible to make the amount not a problem.

  Since the pressure of the gas supplied in the two-fluid nozzle is twice or more (for example, 0.2 MPa or more) larger than normal pressure, the concentration of carbon nanotubes mixed at high pressure is about half when returned to normal pressure.

  In addition, since the mixed fluid is decompressed in the flow path, even if the mixed fluid comes in contact with the conductive fluorocarbon resin material constituting the flow path while being decompressed, the frictional force is reduced, so that the carbon nanotube is detached. Can be reduced.

  Therefore, in Patent Document 4, the upper limit concentration of carbon nanotubes that can be dispersed in the fluorocarbon resin material is considered to be 0.030% by mass in consideration of the influence of mixing, but in the two-fluid nozzle, the same standard is adopted in Patent Document 4 It was found that the influence of the desorbed carbon nanotube can be reduced even if the content is up to 0.060 mass% even if set in consideration of the allowance.

  Furthermore, in the two-fluid nozzle, since the gas is contained in addition to the liquid, the friction by the fluid which is a mixture of them decreases, and the static electricity generated also decreases. Since it turned out that it is also possible to lower the lower limit value of the conductivity required for that purpose, it was possible to make the lower limit value of the content of carbon nanotubes 0.010 mass%.

The present invention has been completed based on the above findings, and the two-fluid nozzle of the present invention has a gas supply port into which a compressed gas is introduced, a liquid supply port to which a liquid is supplied, and the gas and the liquid. It has a main body part which communicates between the spout which spouts the mixed fluid, and between the gas supply port and the spout, and a flow path in which the liquid supply port opens inside;
The flow path is
Between the gas supply port and the jet port, at least one of a convergent part that reduces its diameter from the upstream side, and a divergent part that expands its diameter toward the downstream side, and a part where internal pressure increases With the throat part which is
In the main body portion, a predetermined range downstream of the throat portion and downstream of the liquid supply port is 0.010% or more and 0.060% or less based on the mass of the fluororesin material and the whole. It is formed of a conductive fluororesin material including carbon nanotubes dispersed in the fluororesin material in concentration.

  And the said main-body part can be entirely comprised with the said electroconductive fluorine resin material.

  Further, the liquid supply port can be opened from the throat portion to the divergent portion. By opening the liquid supply port downstream of the throat portion, the fluid in contact with the throat portion will not contain any liquid. By not containing the liquid, a larger expansion occurs from the throat portion to the ejection port, and the influence of the mixture of carbon nanotubes in the throat portion can be reduced.

  Furthermore, the flow path can have both the convergent part and the divergent part. Even if the flow velocity of the compressed gas supplied from the gas supply port is low, it is possible to effectively accelerate the flow velocity in the throat by adopting the convergent part and the divergent part.

  Since the two-fluid nozzle of the present invention can increase the content of carbon nanotubes contained in the conductive fluororesin material by adopting the configuration of the two-fluid nozzle having a proper structure, the conductive fluorine can be obtained. In addition to the fact that the mixing of carbon nanotubes derived from the resin material is not a problem, the effect of being able to exhibit a sufficient antistatic effect can be exhibited.

It is a cross-sectional schematic diagram of the two fluid nozzle of an embodiment.

  The two-fluid nozzle of the present invention will be described in detail below based on the embodiment. Hereinafter, the drawings used in the description are schematic diagrams, and the configurations, the magnitude relationships, etc. to be described can be properly corrected as long as the meaning of the invention is not lost.

  The two-fluid nozzle of the present embodiment has a main body section that divides the flow path. A gas supply port, a liquid supply port, and a jet port are opened in the flow path. The flow path is a flow path for leading the compressed gas supplied from the gas supply port to the ejection port, and a liquid supply port for supplying the liquid to be refined is opened in the middle of the flow path. From the liquid supply port to the spout, the liquid is pulverized into a mixed fluid.

  The flow path has a convergent part which reduces in diameter from the upstream side or a divergent part which expands in the downstream direction, between the gas supply port and the jet port. And it has a throat part which is a part with high internal pressure. As a part with high internal pressure, it is often the most upstream side of the part where the cross-sectional area of the flow path is the smallest. Further, in the case where both the convergent part and the divergent part are provided, the part connecting the convergent part and the divergent part is a throat part. The throat portion is desirably circular in cross section. The throat portion desirably accelerates the velocity of the gas to the speed of sound as the fluid passes therethrough. Acceleration to the speed of sound can be achieved by adjusting the pressure and supply amount of the supplied gas or optimizing the cross-sectional profile in the flow direction of the fluid in the throat. The convergence portion accelerates the gas supplied from the gas supply port. With the divergent portion, even if the velocity of the fluid passing through the throat portion reaches the speed of sound, it can be accelerated to supersonic speed when passing through the divergent portion.

  The liquid supply port is formed to open in the vicinity of the throat portion. In particular, it is preferable because the liquid supplied by opening the liquid supply port slightly downstream of the throat portion does not contact the inner wall of the throat portion. By supplying the liquid downstream of the throat portion, it is preferable because detachment of carbon nanotubes in the conductive fluororesin material by the supplied liquid does not occur.

At least a throat portion of the flow path of the main body portion is formed of a conductive fluororesin material. The conductive fluororesin material contains carbon nanotubes at a concentration of 0.010% to 0.060% based on the total mass. By containing in this range, it becomes possible to impart high conductivity, and an antistatic effect can be exhibited, and the amount of carbon nanotubes mixed into the fluid can be suppressed. In particular, when the content of carbon nanotubes is more than 0.030%, the conductivity can be sufficiently lowered. When the carbon nanotube content is 0.030% by weight and the conductivity is about 1.0 × 10 ³ Ω · cm (as described in Patent Document 4 for the same effect in paragraph 0038), the carbon nanotube content is more than that. With a conductivity of 1.0 × 10 ³ Ω · cm or less, a higher antistatic effect can be exhibited.

  As the upper limit of the amount of carbon nanotubes contained in the conductive fluororesin material, 0.060 mass% can be set. In the case of a two-fluid nozzle in which a gas and a liquid flow as a fluid, the volume of the fluid to be jetted expands rapidly, so the effect of desorption of carbon nanotubes can be reduced unlike in a fluid device where only a liquid flows. The amount of carbon nanotubes contained in the conductive fluororesin material can be 0.05% by mass as the upper limit, and 0.020% by mass and 0.030% by mass as the lower limit. Can.

  Note that Patent Document 4 does not disclose or suggest mixing a liquid and a gas, or a mechanism for mixing a liquid and a gas, and therefore uses either liquid or gas independently. Only things are supposed. Therefore, if the liquid alone does not change the volume after contact with the conductive fluorocarbon resin material, carbon nanotubes of 0.030% by mass or more in which mixing of carbon nanotubes becomes a problem is contained in the conductive fluorocarbon resin material It is difficult, and if the gas alone is used, charging to the gas will not be a problem in the first place, so it is not necessary to suppress the charging by employing a conductive fluororesin material.

  The conductive fluororesin material is composed of a fluororesin material and carbon nanotubes. The fluorine resin material is not particularly limited, and examples thereof include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA).

  As a fluorine resin material, a powdery thing (for example, PTFE G163 made from Asahi Glass) can be used.

Further, as the carbon nanotube, for example, it is desirable to use one having the following characteristics.
Have a fiber length of 50 μm or more and 150 μm or less.
Having a fiber diameter of 5 nm or more and 20 nm or less.
Having a bulk density of 10 mg / cm ³ or more and 70 mg / cm ³ or less.
The G / D ratio is 0.7 or more and 2.0 or less.
Purity is 99.5% or more.
-It is formed in the multilayer (for example, 4-12 layers).

  Here, the fiber length of the carbon nanotube is set to 50 μm or more in order to impart sufficient conductivity with a small amount when the carbon nanotube is dispersed in a fluorocarbon resin material.

  Moreover, G / D ratio is a value which shows ratio of the peak of G-band and the peak of D-band which appear in the Raman spectrum of a carbon nanotube. G-band is derived from a graphite structure, and D-band is derived from a defect. The G / D ratio indicates the ratio of crystal purity to defect concentration of carbon nanotubes.

(Specific example of two-fluid nozzle)
-Configuration As shown in FIG. 1, an example 1 of the two-fluid nozzle of the present embodiment has a main body 10 and a second main body 20. The main body 10 and the second main body 20 are connected by heat fusion. The main body 10 has a flow passage 60 defined therein. In the middle of the flow path 60, a liquid supply port 31 is opened. The liquid supply port 31 is disposed substantially at the center of the cross section of the flow passage 60. The liquid supply port 31 is extended by the liquid supply base 32 from the second main body 20 toward the ejection port 70. The supply of the liquid to the liquid supply port 31 is performed from the liquid supply device connecting unit 30 connected to the liquid supply device (not shown) through the liquid path provided in the liquid supply base 32. It does not specifically limit as a liquid supply apparatus.

  The flow path 60 communicates between the side where the gas supply port 41 is opened (left side in the drawing) and the jet port 70. A plurality of gas supply ports 41 are disposed in a gas supply device connecting unit 40 connected to a gas supply device (not shown), and are disposed around the liquid supply base 32. It does not specifically limit as a gas supply apparatus. The reason for being disposed around the liquid supply base 32 is to make the flow velocity of the gas around the liquid supply port 31 uniform. The purpose of dividing the gas supply port 41 into a plurality is to improve the strength.

  The flow path 60 has a convergent portion 61 whose diameter decreases from the gas supply port 41 side toward the downstream side. And from the downstream, it connects to the jet nozzle 70 by the same diameter. The portion that is most reduced in diameter from the convergent portion 61 is the portion where the gas pressure is the highest, and corresponds to the throat portion 62. A downstream portion of the throat portion 62 may be provided with a divergent portion which is expanded toward the downstream side. It is preferable that the liquid supply port 31 can be opened in the vicinity of the throat portion 62, and in particular, opened on the downstream side of the throat portion 62. In the two-fluid nozzle of the present embodiment, the downstream side of the throat portion 62 is opened.

  In the main body portion 10, at least a predetermined range 63 on the downstream side of the liquid supply port 31 is formed of a conductive fluororesin material. When the liquid supply port 31 opens on the upstream side of the throat portion 62, the throat portion 62 is formed of a conductive fluororesin material. Here, the entire main body portion 10 can be formed of a conductive fluororesin material. The conductive fluororesin material contains carbon nanotubes at a concentration of 0.010% by mass or more and 0.060% by mass or less. The portion of the main body portion 10 which is not formed of the conductive fluorocarbon resin material and the material for forming the second main body portion 20 are not particularly limited, but can be formed of a general fluorocarbon resin material. As a specific fluorocarbon resin material, the same thing as the fluorocarbon resin material which comprises the conductive fluorocarbon resin material mentioned above can be illustrated. The fluorine resin material employed for the conductive fluorine resin material and the fluorine resin material forming the other part may be the same or different.

  A conductive member (not shown) electrically connected to the outside can be formed in a portion (a predetermined range 63 on the downstream side in the present embodiment) of the main body portion 10 formed of the conductive fluorocarbon resin material. The conductive member can effectively suppress charging by grounding it to a proper part.

・ Operation effect
The operation and effects of the two-fluid nozzle of the present embodiment will be described. The liquid supply device supplies pure water as a liquid, and the gas supply device supplies air as a gas. Although pure water was mentioned as an example of a liquid, other liquids can be adopted according to a use. Then, in addition to the liquid, the particulate material may be dispersed. In addition to the liquid supply port 31, a second liquid supply port for supplying another liquid may be provided. The liquid supplied from the liquid supply port 31 may apply pressure. Also, the distance of the liquid may be controlled appropriately. The feed rate of the liquid is properly determined in accordance with the amount of liquid desired to be contained in the mixed fluid to be jetted.

  As the gas, in addition to air, ordinary gases such as carbon dioxide, oxygen, nitrogen and argon can be adopted. The gas to be supplied is compressed and can be, for example, a supply pressure of about 0.2 MPa to about 1.0 MPa, particularly preferably 0.25 MPa or more, and preferably 0.6 MPa or less. The gas supplied to the gas supply port 41 can properly control the temperature, humidity, and the like. It can be heated, cooled, humidified or dried.

  The gas supplied from the gas supply port 41 generates a flow toward the spout 70 because it is compressed. The flow of gas supplied from the gas supply port 41 is accelerated by the presence of the convergent section 61. Then, when the throat portion 62 is reached, the cross-sectional shape does not change after that and since the jet port 70 is opened to the atmospheric pressure, the flow is further accelerated while the volume is increased. In particular, when a high-pressure gas is introduced from the gas supply port 41 and the speed of sound is reached in the throat section 62, a divergent section is formed to expand in diameter from the throat section 62 toward the ejection port 70. It is also possible that the flow of gas exceeds the speed of sound. Here, even if the flow of gas comes in contact with the wall surface of the flow passage 60, charging due to friction does not occur.

  In the throat portion 62, since the flow of the gas is fast, the liquid supplied with the liquid from the liquid supply port 31 becomes fine droplets 90 and is ejected from the ejection port 70 together with the flow of the gas. The droplets on the gas flow rub against the wall surface of the flow passage 60, but since the inner surface of the flow passage 60 is formed of the conductive fluorocarbon resin material, charging can be suppressed. Even if the carbon nanotubes contained in the conductive fluorocarbon resin material are desorbed due to the friction with the wall surface of the flow channel 60, the concentration thereof is reduced to a problem-free carbon nanotube concentration as described above.

  As described above, even if the wall surface of the flow path 60 has a carbon nanotube content of 0.010% by mass or more, by setting the content to 0.060% by mass, sufficient conductivity can be exhibited and it is finally jetted. There is no problem in the concentration of carbon nanotubes in the mixed fluid.

  For the purpose of supporting the above results, the conductive fluorine containing the carbon nanotube in an amount of 0.060% by mass of the main body portion 10 and the second main body portion 20 of the two-fluid nozzle 1 intended for a mixed fluid of liquid and gas As a result of examining the degree of electrification and the amount of carbon nanotubes to be mixed when jetted out using pure water as a liquid and air as a gas as a result of trial manufacture of one made of a resin material, sufficient electrification prevention It was confirmed that the effect was exhibited and that the amount of carbon nanotubes contained was within the allowable range. The amount of carbon nanotubes mixed in the fluid device for liquid as described in Patent Document 4 is a carbon nanotube that occurs when a conductive fluorocarbon resin material containing 0.025% of carbon nanotubes is employed. The amount was equal to or less than the amount of contamination.

  Furthermore, in order to confirm the antistatic effect, a two-fluid nozzle in which the main body portion 10 and the second main body portion 20 were entirely formed of a conductive fluorocarbon resin material containing 0.010 mass% of carbon nanotube content was manufactured. As a result, charging did not occur which would be a problem under normal conditions. Incidentally, in the case of the two-fluid nozzle in which the content of the above-mentioned carbon nanotube is 0.06 mass%, the friction becomes large because of the severe conditions (large proportion of liquid, high supply pressure of gas, etc.) Under the above conditions, sufficient antistatic effect was exhibited. As the amount exceeds 0.030% by mass, it is predicted that the antistatic effect is higher when the carbon nanotube is contained.

DESCRIPTION OF SYMBOLS 1 ... 2 fluid nozzle 10 ... main-body part 20 ... 2nd main-body part 30 ... liquid supply apparatus connection part 31 ... liquid supply port 32 ... liquid supply base 40 ... gas supply apparatus connection part 41 ... gas supply port 60 ... flow path 61 ... Convergent part 62 ... Throat part 63 ... Predetermined range on the downstream side

Claims (4)

A gas supply port through which the compressed gas is introduced, a liquid supply port through which the liquid is supplied, an ejection port through which the gas and a mixed fluid of the liquid are ejected, the gas supply port and the ejection port It has a main body which communicates with and internally defines a flow passage in which the liquid supply port is opened,
The flow path is
Between the gas supply port and the jet port, at least one of a convergent part that reduces its diameter from the upstream side, and a divergent part that expands its diameter toward the downstream side, and a part where internal pressure increases With the throat part which is
In the main body portion, a predetermined range downstream of the throat portion and downstream of the liquid supply port is 0.010% or more and 0.060% or less based on the mass of the fluororesin material and the whole. It is formed of a conductive fluororesin material including carbon nanotubes dispersed in the fluororesin material in concentration,
Two fluid nozzle.   The two-fluid nozzle according to claim 1, wherein the main body portion is entirely made of the conductive fluororesin material.   The two-fluid nozzle according to claim 1, wherein the liquid supply port opens from the throat portion to the divergent portion.   The two-fluid nozzle according to any one of claims 1 to 3, wherein the flow path has both the convergent part and the divergent part.

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