JP2012030179A - Micronizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micronizer capable of micronizing liquid fine particles with a simple micronizer structure.SOLUTION: The micronizer includes an atomizer and a liquid surface micronizer for forming a liquid surface and repelling liquid fine particles atomized from the atomizer by the liquid surface to micronize the liquid fine particles.

Description

  The present invention relates to a miniaturization apparatus for miniaturizing liquid fine particles sprayed from a spraying apparatus.

  In recent years, in the fields of medical equipment (for example, inhalers), semiconductors (film formation technology), spray dryers (new ceramic materials), combustion burners, etc., there is a demand for average particle diameters and spray amounts according to the product purpose. ing. However, current atomization techniques include gas-liquid mixing type (two-fluid type), ultrasonic type, ultra-high pressure type (100 MPa to 300 MPa), evaporation type, and the like. In order to satisfy the spray amount, the cost of the apparatus is high and miniaturization is difficult.

  As a gas-liquid mixing type, a spray nozzle device for generating fine particle mist is known (Patent Document 1). This spray nozzle device has a first nozzle part and a second nozzle part, and can collide the spray liquid from the first nozzle part with the spray liquid from the second nozzle part to form a fine particle mist. . However, since two two-fluid nozzle portions are provided, the cost is high and it is not suitable for downsizing.

Japanese Patent Laid-Open No. 2002-126587

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a miniaturization apparatus capable of miniaturizing liquid fine particles with a simple apparatus configuration.

  The miniaturization apparatus of the present invention includes a spray means and a liquid level refinement means for forming the liquid level and repelling the liquid fine particles sprayed from the spray means on the liquid level to refine the liquid fine particles. And have.

  According to this configuration, the liquid fine particles sprayed from the spraying means are repelled on the liquid level of the liquid level refining means, whereby the liquid fine particles can be suitably miniaturized. The mechanism of miniaturization is as follows. For example, by spraying liquid fine particles onto the liquid surface, gravitational acceleration is also added, and fine particles having a large mass (fine particles having a large particle diameter) tend to be in contact with the liquid surface, and have a large particle diameter in contact with the liquid surface. The fine particles are considered to mix with the liquid as it is, while the fine particles with a small mass (fine particles with a small particle diameter) float before contacting the liquid surface and move, for example, in a low pressure direction such as an opening. It is considered that even if it contacts the liquid surface, it tends to move in the low pressure direction without mixing with the liquid. That is, by eliminating the liquid fine particles having a large particle diameter, the average particle diameter of the entire liquid fine particles can be reduced and the liquid fine particles can be miniaturized.

  Examples of the spray means include a one-fluid nozzle device, a two-fluid nozzle device, an ultrasonic device, an ultra-high pressure spray device, and an evaporation spray device. The liquid level refinement means includes at least a storage section that stores the liquid constituting the liquid level. The liquid is not particularly limited as long as it is liquid, and examples thereof include water and liquid fine particle supply liquid. The liquid level may be one or two or more. The area of the liquid surface can be set according to the spray area of the liquid fine particles.

  The liquid surface refinement means may have a liquid storage portion and a wall portion extending upward from the storage portion, and a through opening may be formed in the wall portion. It can be configured that the liquid fine particles enter from the upper opening of the wall portion, the liquid fine particles bounce off the liquid surface, and flow out from the through opening.

  The angle at which the liquid fine particles sprayed from the spraying unit contacts (or collides) with the liquid surface is not particularly limited. For example, the liquid fine particles may contact perpendicularly or obliquely with respect to the liquid surface. In such a case, the wall portion of the liquid level refinement means may be formed perpendicular to the liquid level or may be formed inclined with respect to the liquid level.

  Further, as one embodiment of the present invention, it is preferable to further include a first refining means for refining the liquid fine particles before the liquid fine particles sprayed from the spraying means reach the liquid surface.

  According to this configuration, since the liquid fine particles can be refined by the first refinement means and then the liquid fine particles can be refined by the liquid surface refinement means, the liquid particulates can be further refined. Examples of the first miniaturization means include a cylindrical baffle, a baffle having a cylindrical portion and a flare portion (with a vertical slit) in which one of the cylindrical portions is expanded. The first refinement means may be arranged inside the wall portion of the liquid level refinement means.

  Further, as an embodiment of the invention, there is a configuration further including a second refining means for further refining the liquid fine particles after the refining process by the liquid surface refining means.

  According to this configuration, the liquid fine particles can be refined by the liquid surface refinement means, and further, the liquid fine particles can be refined by the second refinement means. Further, by incorporating the miniaturization of the first miniaturization means, it is possible to obtain liquid fine particles subjected to three-stage miniaturization. Examples of the second refinement means include a cylindrical baffle, and a baffle having a cylindrical portion and a flare portion (with a vertical slit) in which one of the cylindrical portions spreads. The second miniaturization means may be arranged in the vicinity of the through opening, or may be arranged so as to be connected to the through opening.

  Moreover, as one embodiment of the invention, the miniaturization apparatus has a miniaturization chamber into which the liquid fine particles sprayed from the spraying means are supplied by spraying, and the miniaturization chamber has an opening leading to the outside of the apparatus main body. The liquid level refinement means is provided below the refinement chamber.

  According to this configuration, the liquid fine particles sprayed from the spray means toward the liquid surface are refined by the liquid surface refinement means of the refinement chamber, and are finely formed from, for example, an opening formed on the side surface or the upper part of the refinement chamber. The liquid fine particles can be released. The opening may be configured as a penetrating portion of the wall, and a discharge pipe (for example, a straight pipe, an elbow-like pipe, or the like) that is connected to the opening and protrudes from the wall can be provided. The miniaturization chamber may be configured to be in contact with the liquid level or may be disposed at a position higher than the liquid level. The miniaturization chamber may be connected to the wall portion of the liquid level miniaturization means. In the case where an opening is formed in the miniaturization chamber, the through-opening of the wall portion may be omitted or may be present. The second miniaturization means may be arranged in the vicinity of the opening of the miniaturization chamber, or may be arranged so as to be connected to the opening.

  Moreover, as one embodiment of the invention, there is a configuration further including a gas supply unit that supplies a gas along the spray direction of the liquid microparticles in the vicinity of the spray portion of the spray unit. The gas supplied from the gas supply means defines the traveling direction of the liquid fine particles sprayed from the spray means, and can function as a liquid fine particle transport means.

  Moreover, the spray amount of the liquid fine particles sprayed from the spraying means can be increased or decreased by the action of the gas by the gas supply means. The gas supply means can increase the spray amount of the liquid fine particles sprayed from the spray means as a result, for example, by jetting the gas under pressure, rather than the configuration without it. Examples of the gas include air, clean air (clean air), nitrogen, inert gas, fuel mixed air, oxygen, and the like, and can be set as appropriate according to the purpose of use.

  Moreover, as one embodiment of the invention, the spraying means is a two-fluid nozzle, the two-fluid nozzle is disposed to face the liquid surface, and sprays liquid particles toward the liquid surface.

  Moreover, as one embodiment of the present invention, a liquid constituting the liquid level of the liquid level refinement means is a supply liquid supplied to the two-fluid nozzle. According to this configuration, it is not necessary to prepare separate liquids, and the problem of contamination between liquids does not occur. When supplying the liquid of the liquid level refinement means to the two-fluid nozzle, the height of the liquid level varies. In this case, the liquid may be supplied to the two-fluid nozzle as long as there is substantially no influence of miniaturization due to the rebound of the liquid fine particles. In addition, liquid supply means, liquid level detection means, etc. are installed so that the liquid level can be supplied to the liquid level refinement means so that the liquid level can be kept constant or within a range where height fluctuation is acceptable. Can be kept.

It is a cross-sectional schematic diagram of an example of the front-end | tip part of a two-fluid nozzle. It is a figure which shows an example of a miniaturization apparatus. It is a figure which shows an example of a miniaturization apparatus. It is a figure which shows an example of a miniaturization apparatus. It is a figure which shows an example of a miniaturization apparatus. It is a figure which shows an example of a miniaturization apparatus. It is a figure which shows an example of a miniaturization apparatus. It is a figure which shows the particle size distribution of Experimental example 7. It is a figure which shows the particle size distribution of Experimental example 8.

  The miniaturization apparatus of the present embodiment will be described using a two-fluid nozzle as an example of the spraying means. As the two-fluid nozzle, a normal two-fluid nozzle can be used without limitation, and is naturally not limited to the two-fluid nozzle described below. The two-fluid nozzle realizes a primary refining function for refining liquid with air.

  An example of a two-fluid nozzle will be described with reference to FIG. FIG. 1B is a cross-sectional view of the spray portion of the two-fluid nozzle 1, and FIG. 1A is a cross-sectional view of the inner nozzle 12. The inner nozzle 12 forms a top surface 12c (a trapezoidal top surface) of the inner nozzle, and an inner orifice 12a (inner orifice diameter: φd2) is formed at the center thereof. The inner orifice 12a is formed in the inner flow portion 12b ( Corresponding to the first flow path). Convex portions 12 d are formed at four locations on the outer wall of the inner nozzle 12, and this convex portion 12 d abuts against the inner wall of the outer nozzle 11 to form an outer circulation portion 11 b (corresponding to a second flow passage). The inner nozzle 12 is incorporated in the outer nozzle 11 so that the outer orifice 11a and the inner orifice 12a are formed on the same axis, and the top surface 12c and the inner wall portion of the outer nozzle opposed to the top surface 12c have a predetermined distance. A gap L1 is formed. The outer diameter of the top surface 12c is preferably larger than the outer orifice diameter (φd1), for example, and is not particularly limited, but examples include a range of 0.2 mm to 5.0 mm.

  When the “first fluid” flowing through the inner orifice and the first flow passage is made into a gas, the “second fluid” flowing through the outer orifice and the second flow passage is a liquid (this case is referred to as “inner air system”). That said.) Further, as an opposite pattern, when the “first fluid” flowing through the inner orifice and the first flow passage is made liquid, the “second fluid” flowing through the outer orifice and the second flow passage is a gas (this The case is called “outside air method”). In the present invention, the liquid fine particles can be sprayed in any pattern without any particular limitation. However, in the case of the inner air method, the average particle diameter is smaller than that of the outer air method even in the case of a low pressure gas supply pressure (for example, 10 kPa to 100 kPa or less). Small liquid particles can be sprayed, and the particle size range (maximum, minimum, deviation) of the sprayed liquid particles can be suitably adjusted.

  As a constituent member of the two-fluid nozzle, a known member can be used. For example, the two-fluid nozzle can be made of metal, plastic, rubber, or a mixture thereof.

  The “gas” supplied to the two-fluid nozzle is not particularly limited, and examples thereof include gases such as air, clean air, high oxygen concentration air, and inert gas. The “liquid” supplied to the two-fluid nozzle is not particularly limited. For example, cosmetics such as water, ionized water and lotion, chemicals such as pharmaceutical liquids, bactericidal liquids and disinfecting liquids, paints, and fuel oils. , Coating agents, solvents, resins and the like.

  The supply pressure of the gas supplied to the two-fluid nozzle is not particularly limited, and examples thereof include a range of 10 kPa to 500 kPa. The supply pressure of the liquid may be free, for example, without any external action such as the supply pressure of the liquid, or the pressure may be applied to the liquid. Moreover, both an outside air system and an inside air system are possible. Since the gas supply pressure can be reduced, the driving source (for example, a compressor, an air pump, a power source, a compressed air cylinder, and a manual air supply mechanism) necessary for gas supply of the two-fluid nozzle can be reduced in size.

(Liquid level refinement means)
The liquid level refinement means 2 will be described with reference to FIG. The liquid level refinement means 2 has a reservoir 20 that stores the liquid 21 and forms a liquid level 211. The liquid fine particles 100 sprayed from the two-fluid nozzle 1 bounce off the liquid surface 211 (see reference numeral 101). The liquid fine particles 100 are sprayed in the direction of the liquid surface 211 and bounce off the liquid surface 211, whereby the number of particles having a large particle diameter in the liquid fine particles can be reduced. As a result, the liquid fine particles are refined. be able to. The liquid fine particles bounced off from the liquid surface 211 can be transported to a destination through the pipe, for example, by installing a pipe or the like at a position where the liquid bounces back.

  FIG. 3 is an example of a liquid surface miniaturization means different from FIG. The storage part 20a of the liquid level refinement means 2 in FIG. 3 has a two-fluid nozzle 1 which can be detachably attached, and has an outlet part 22 serving as an outlet of the liquid particulates 102 above the liquid level. . The outlet portion 22 is not limited to the upper side, and may be formed on the side surface of the storage portion 20a. A pipe serving as a path for sending the liquid fine particles 102 to an arbitrary destination may be connected to the outlet 22. The shape of the reservoir 20a is not particularly limited to the shape shown in FIGS. 2 and 3, and is not particularly limited as long as the object of the present invention can be realized. The reservoir 20a may be formed with a through hole (not shown) that penetrates the wall surface of the reservoir 20a for adjusting the internal air pressure. You may comprise the opening area of this through-hole variably. Moreover, a through hole can be formed in the vicinity of the spray port of the two-fluid nozzle 1, and gas can be supplied from the through hole. The means for supplying the gas can be constituted by, for example, a blower or a compressor.

  The distance (D1) from the spray port of the two-fluid nozzle 1 to the liquid surface 211 is not particularly limited, but examples include a range of 20 mm to 1000 mm, and a range of 30 mm to 500 mm is preferable from the viewpoint of controlling the average particle diameter, The range of 30 mm to 300 mm is more preferable, and the range of 30 mm to 200 mm is more preferable.

  Alternatively, the liquid 21 may be sucked up to the inner nozzle of the two-fluid nozzle 1 to constitute a liquid supply liquid particle. The liquid 21 can be sucked up by, for example, a pipe (not shown) or the like disposed from the wall surface of the storage units 20a, 20 at a position lower than the liquid level 211 to the liquid supply unit of the two-fluid nozzle 1. The liquid supply pressure can be set to zero, and the liquid 21 can be sucked up by a negative pressure action by gas spraying.

(First refinement means)
The first micronization means shown in FIG. 4 is a cylindrical baffle 3 that extends from the spray portion of the two-fluid nozzle 1 toward the liquid surface 211. A predetermined interval 31 is formed from the lower end of the cylindrical baffle 3 to the liquid surface 211, and fine liquid particles refined from the predetermined interval 31 can be guided to an opening (not shown). The “cylindrical shape” is a concept in which the cross section may be a perfect circle or an ellipse, and includes a cylindrical shape having a polygonal cross section. Further, the cylindrical baffle 3 may be formed with a through hole (not shown) penetrating the wall surface of the cylindrical baffle 3 for adjusting the internal air pressure. You may comprise the opening area of this through-hole variably. Moreover, a through hole can be formed in the vicinity of the spray port of the two-fluid nozzle 1, and gas can be supplied from the through hole. The means for supplying the gas can be constituted by, for example, a blower or a compressor.

  The cylindrical baffle 3 refines the liquid fine particles sprayed from the two-fluid nozzle 1 and can efficiently guide the sprayed liquid fine particles downward, and the fine particles (sprays) having a large particle diameter can be guided to the wall surface of the cylindrical baffle 3. It is also possible to grow into droplets by contacting them. Then, the liquid fine particles bounce off the liquid surface 211, and the fine particles having a small particle diameter are released to the outside through the gap of the interval 31, and are guided to the opening (low pressure direction). Although the distance D2 of the “predetermined interval 31” is not particularly limited, for example, although it depends on the distance D1 from the spray port of the two-fluid nozzle to the liquid surface 211, a range of 0.5 mm to 50 mm is exemplified.

  The first refinement means shown in FIG. 5 is a cylindrical baffle 4 that extends from the spray portion of the two-fluid nozzle 1 into the liquid 21. The cylindrical baffle 4 has an opening 41 on the upper side of the side wall, and fine liquid particles that flow out of the opening 41 flow out of the cylindrical baffle 4. The “cylindrical shape” is a concept in which the cross section may be a perfect circle or an ellipse, and includes a cylindrical shape having a polygonal cross section. Further, the cylindrical baffle 4 may be formed with a through hole (not shown) penetrating the wall surface of the cylindrical baffle 4 for adjusting the internal air pressure. You may comprise the opening area of this through-hole variably. Moreover, a through hole can be formed in the vicinity of the spray port of the two-fluid nozzle 1, and gas can be supplied from the through hole. The means for supplying the gas can be constituted by, for example, a blower or a compressor.

  The cylindrical baffle 4 refines the liquid fine particles sprayed from the two-fluid nozzle 1 and can efficiently guide the sprayed liquid fine particles downward, and the fine particles (sprays) having a large particle diameter can be guided to the wall surface of the cylindrical baffle 4. It is also possible to grow into droplets by contacting them. Then, the liquid fine particles bounce off the liquid surface 211, and the fine particles having a small particle diameter are guided to the opening 41 (low pressure direction). When the opening 41 is above, a large number of fine particles having a small particle diameter tend to be released.

  Further, as another first miniaturization means, the lower part of the cylindrical baffle 3 can be formed in a flared shape, and a vertical slit can be formed in the flared portion. The sprayed liquid fine particles come into contact with the baffle, and the liquid fine particles having a large particle diameter grow into droplets and fall into the storage unit 20.

(Miniaturization room)
The micronization chamber 6 shown in FIG. 6 includes a cylindrical guide 61 that guides liquid particles sprayed vertically downward from the two-fluid nozzle 1 to the liquid surface 211, and a cylinder that communicates with the side of the cylindrical guide 61. The lower end of the miniaturization chamber 6 is disposed in the liquid 21 of the liquid level refinement means 2. The liquid fine particles bounced off from the liquid surface 211 flow out from the cylindrical opening 62. The direction of the opening center axis of the cylindrical opening 62 is an obliquely upward direction in FIG. 6, but is not particularly limited thereto, and may be a direction perpendicular to the opening center axis of the cylindrical guide part 61 or may be obliquely below. Good. The said cylindrical guide part 61 can also serve as a function as said 1st refinement | miniaturization means.

  7 includes a cylindrical guide portion 71 that guides the liquid fine particles sprayed obliquely downward from the two-fluid nozzle 1 to the liquid level 211, and the liquid fine particles bounced off the liquid level 211. Has a cylindrical opening 72 that flows out to the outside, and the lower end of the miniaturization chamber 7 is disposed in the liquid 21 of the liquid level refinement means 2. The direction of the opening center axis of the cylindrical opening 72 is the vertical direction in FIG. 7, but is not particularly limited thereto, and may be inclined in an oblique direction. The said cylindrical guide part 71 can also serve as a function as said 1st refinement | miniaturization means.

(Second refinement means)
Moreover, the structure which has the 2nd refinement | miniaturization means which continues in the said cylindrical opening parts 62 and 72 and refines | miniaturizes a liquid particulate further is possible. For example, the second miniaturization means can be formed in an elbow shape whose longitudinal direction is bent. Due to this elbow shape, contact with the wall surface easily occurs and miniaturization is promoted.

(Experimental example 1)
A two-fluid nozzle shown in FIG. 1 was used, and a container was used as the liquid level refinement means shown in FIG. The amount of rebound liquid particles (return fog amount (RF amount): f [ml / min]) when the vertical distance (D1) from the spray port of the two-fluid nozzle to the liquid surface is changed between 50 mm and 300 mm, The average particle diameter (visual observation) was evaluated. The two-fluid nozzle was sprayed under the following conditions using water and air by an internal air system. Note that the spray amount of the liquid fine particles sprayed from the two-fluid nozzle is defined as a primary spray amount (Qw). The results are shown in Table 1.
Two-fluid nozzle: L1 = 0.195 mm in FIG.
Outer orifice diameter (φd1) = 0.4mm,
Inner orifice diameter (φd2) = 0.24mm,
Distance (D1) from the two-fluid nozzle spraying port (outside orifice outlet) to the liquid level = 50, 100, 150, 200, 250, 300 mm,
Air pressure (Pa) = 0.1 MPa (the air supply drive source is a compressor),
Water pressure = 0
Air flow rate (Qa) = 0.80NL / min,
Primary spray amount (Qw) of the two-fluid nozzle = 4.44 ml / min (adjusted so as to be this value),
Average particle diameter of primary spray (visual observation) = 35 μm.

(Experimental example 2)
Except that the air pressure (Pa) = 0.05 MPa, the air flow rate (Qa) = 0.57 NL / min, and the primary spray amount (Qw) = 3.98 ml / min, they are the same as in Experimental Example 1. Note that the average particle diameter of the primary spray (visual observation) = 35 μm. The results are shown in Table 2.

(Experimental example 3)
It is the same as Experimental Example 1 except that the air pressure (Pa) = 0.20 MPa, the air flow rate (Qa) = 1.19 NL / min, and the primary spray amount (Qw) = 8.02 ml / min. Note that the average particle diameter of the primary spray (visual observation) = 35 μm. The results are shown in Table 3.

  From the results of the above experimental examples 1 to 3, the smaller the distance D1 from the spray port of the two-fluid nozzle to the liquid level, the smaller the average particle diameter of the liquid fine particles by visual observation, and the return fog amount (RF amount) is also It was confirmed that the tendency to become smaller.

(Experimental example 4)
In Experimental Example 4, the two-fluid nozzle was sprayed vertically downward using the miniaturization chamber of FIG. The measurement was performed under two conditions: a case where the lower end of the miniaturization chamber was sprayed in the liquid, and a case where a gap of 50 mm was provided between the lower end and the liquid surface. The conditions of the two-fluid nozzle are the same as those in Experimental Example 1, the air pressure (Pa) = 0.1 MPa, the air flow rate (Qa) = 0.80 NL / min, the primary spray amount (Qw) of the two-fluid nozzle = 4.44 ml / min. It was set to min. The vertical distance (height) (D1) from the two-fluid nozzle spraying port (outside orifice outlet) to the liquid level was set to 200 mm. Note that the average particle diameter of the primary spray (visual observation) = 35 μm. The results are shown in Table 4.

(Experimental example 5)
In Experimental Example 5, the two-fluid nozzle was sprayed obliquely downward at 45 ° C. using the miniaturization chamber of FIG. The measurement was performed under two conditions: a case where the lower end of the miniaturization chamber was sprayed in the liquid, and a case where a gap of 50 mm was provided between the lower end and the liquid surface. The conditions of the two-fluid nozzle are the same as in Experimental Example 4, the air pressure (Pa) = 0.1 MPa, the air flow rate (Qa) = 0.80 NL / min, the primary spray amount (Qw) of the two-fluid nozzle = 4.44 ml / min. It was set to min. The height distance (D1) from the two-fluid nozzle spraying port (outside orifice outlet) to the liquid level was set to 200 mm. Note that the average particle diameter of the primary spray (visual observation) = 35 μm. The results are shown in Table 5.

  From the results of the above experimental examples 4 and 5, in the case of the above conditions, although the vertical spray tends to have a smaller average particle diameter of the liquid fine particles by visual observation than the oblique downward spray of 45 °, the return fog It can be seen that the amount (RF amount) tends to be small. This is probably because the difference in the residual amount of liquid fine particles with a large particle size appears in the results of both of them, and it is speculated that the lower spray at 45 ° obliquely contains more particles with a large particle size. Is done.

(Experimental example 6)
A two-fluid nozzle shown in FIG. 1 was used, and a container was used as the liquid level refinement means shown in FIG. When the vertical distance (D1) from the spray port of the two-fluid nozzle to the liquid surface is 200 mm, the average particle diameter of the primary spray (Qw) sprayed from the two-fluid nozzle and the liquid fine particles bounced off the liquid surface (return fog ( RF)) average particle size. The evaluation method is such that the primary spray liquid fine particles and the liquid fine particles after rebounding are received with 20 mm × 15 mm size water sensitive paper (manufactured by Syngenta), and the liquid fine particles are determined from the spot area by the liquid, the average diameter of the spots, and the total number of spots. The average particle diameter was calculated (hereinafter referred to as water sensitive paper evaluation method). A liquid particle having a known particle diameter is measured, and a relative arithmetic can be performed by comparison with the measured liquid particle.

The two-fluid nozzle was sprayed under the following conditions using water and air by an internal air system.
Two-fluid nozzle: L1 = 0.195 mm in FIG.
Outer orifice diameter (φd1) = 0.4mm,
Inner orifice diameter (φd2) = 0.24mm,
Air pressure (Pa) = 0.2 MPa (the air supply drive source is a compressor),
Air flow rate (Qa) = 36.0 NL / min,
Water pressure = 0.38 MPa,
Primary spray amount (Qw) of the two-fluid nozzle = 55 ml / min (adjusted to be this value).

  The particle size distribution of primary spray (Qw) and return fog (RF) is shown in FIG. The arithmetic mean particle size of primary spray (Qw) was 33.6 μm, and MMD (Mass Median Diameter) was 62.7 μm. On the other hand, the RF amount of the return fog (RF) was 8 ml / min, the RF rate was 14.5%, the arithmetic average particle diameter was 22.6 μm, and the MMD was 38.0 μm.

(Experimental example 7)
In Experimental Example 7, the conditions of the two-fluid nozzle were as follows, and the other conditions were the same as in Experimental Example 6.
Two-fluid nozzle: L1 = 1.0 mm in FIG.
Outer orifice diameter (φd1) = 3.0 mm,
Inner orifice diameter (φd2) = 2.5 mm,
Air pressure (Pa) = 0.2 MPa (the air supply drive source is a compressor),
Air flow rate (Qa) = 80 NL / min,
Water pressure = 0.15 MPa,
Primary spray amount (Qw) of the two-fluid nozzle = 160 ml / min (adjusted so as to be this value).

  The particle size distribution of primary spray (Qw) and return fog (RF) is shown in FIG. The arithmetic mean particle size of primary spray (Qw) was 27.5 μm, and MMD (Mass Median Diameter) was 37.8 μm. In contrast, the return fog (RF) had an RF amount of 56 ml / min, an RF rate of 35.0%, an arithmetic average particle size of 24.5 μm, and an MMD of 36.1 μm.

  From the results of Experimental Examples 6 and 7, it can be seen that the return fog (RF) has a narrower particle diameter range than the primary spray (Qw), and the number of liquid particles having a smaller particle diameter tends to increase. It could be confirmed.

1 Two-fluid nozzle 2 Liquid surface refinement means 6, 7 Refinement chamber
211 Liquid level

Claims (5)

Spraying means;
And a liquid surface refining unit that forms a liquid surface and repels the liquid fine particles sprayed from the spraying means on the liquid surface, thereby refining the liquid fine particles.   2. The miniaturization apparatus according to claim 1, further comprising a first micronization unit that micronizes the liquid fine particles before the liquid fine particles sprayed from the spraying unit reach the liquid level. The micronization device further includes a micronization chamber into which liquid fine particles sprayed from the spraying means are supplied by spraying.
The miniaturization apparatus according to claim 1, wherein an opening leading to the outside of the apparatus main body is formed in the miniaturization chamber, and the liquid level miniaturization means is provided below the miniaturization chamber.   The fine according to any one of claims 1 to 3, wherein the spraying means is a two-fluid nozzle, and the two-fluid nozzle is disposed to face the liquid surface and sprays liquid fine particles toward the liquid surface. Device. The miniaturization apparatus according to claim 4, wherein the liquid constituting the liquid level of the liquid level refinement unit is a supply liquid supplied to the two-fluid nozzle.

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