JP7518592B2 - Fine particle manufacturing equipment - Google Patents

Description

The present invention relates to a microparticle manufacturing device.

A particle manufacturing device that utilizes spray pyrolysis is used as a method for manufacturing fine particles. A spray pyrolysis device is a device that sprays the material to be synthesized (mainly a solution) inside a furnace tube made of ceramics, metal, heat-resistant bricks, etc., and heat-treats the material to be synthesized to produce particles. The heat source for heating the material to be synthesized can be an internal combustion type, such as a gas burner, or an external heat type, such as an electric heater or hot air heater.

A spraying device (nozzle unit) is installed to spray the compound into the furnace tube. The nozzle sprays the solution delivered by a pump or the like from the tip together with compressed air, creating a mist and forming fine particles. The nozzles mainly used in spray pyrolysis devices include two-fluid nozzles with one solution line and one compressed air line, three-fluid nozzles with one solution line and two compressed air lines, and four-fluid nozzles with two solution lines and two compressed air lines. These nozzles are selected according to the target particle size of the product and the target production volume. The diameter of the fine particles can also be controlled by adjusting the input ratio of the solution and compressed air. A resin packing member may be used at the tip of these nozzles.

These microparticles are dried and sintered inside the furnace tube, becoming fine particles as the product. The fine particles are collected using a suction fan to create negative pressure inside the furnace tube and a bag filter or similar. To obtain the target specific gravity and particle size, the processing conditions include controlling the processing time and temperature.

When spraying for a long period of time, particulate manufacturing equipment can cause adhesions caused by the raw material solution around the mist outlet at the tip of the nozzle. This adhesion can impede the mist and prevent normal spraying, which can cause problems such as variations in the particle size and density of the product. Therefore, it is essential to remove this adhesion. Methods for removing adhesions include mechanical removal, removal using air, and removal using liquid.

Patent Document 1 discloses a technology for removing foreign matter adhering to the nozzle end of a spray gun that sprays liquid from the center of the nozzle end and gas from a gas passage between the outer periphery of the nozzle end and the outer cylinder, in which a scraping blade is provided on the outer periphery and end face of the outer periphery that can rotate or rotate freely to remove foreign matter adhering to the nozzle end.

Patent Document 2 discloses a granulation coating device capable of removing adhesions that have adhered to the spray nozzle of the spray means, the device having a spray means 27 that sprays a binder or coating agent onto the workpiece contained in the rotating drum, a brush 30 that is provided within the rotating drum so as to be movable relative to the spray means 27 and that comes into contact with the nozzle 26 of the spray means 27 to remove adhesions that have adhered to it, and an adhesion suction device 31 that is provided near the brush 30 and collects the removed adhesions.

Japanese Unexamined Patent Publication No. 60-241956 Japanese Patent Application Publication No. 7-246354

The technology described in Patent Document 1 uses a nozzle that does not cause adhesion at the nozzle tip (apex), and the scraping blade only has the function of removing adhesion that occurs around it. In other words, it is not possible to remove adhesion that occurs at the nozzle tip. The nozzles used in the spray pyrolysis method can spray a large amount of fine mist with a single nozzle, but such nozzles do not necessarily have the characteristic of not causing adhesion at the nozzle tip, so it is necessary to remove adhesion at the nozzle tip as well. In addition, because the scraping blade is always waiting near the spray nozzle, adhesion occurs starting from the scraping blade.

In addition, in the technology described in Patent Document 2, the brush comes into contact with the entire nozzle, making it possible to remove adhesions from the nozzle tip as well. However, the tip of the nozzle used in the spray pyrolysis method is a delicate component, and so there is a risk that the state of the sprayed mist will change if the brush comes into direct contact with the nozzle to remove adhesions. In particular, if the tip of the nozzle has a resin packing member, direct contact with the brush can damage the packing member, preventing normal spraying and accelerating wear of the packing.

The present invention was made in consideration of these circumstances, and aims to provide a microparticle manufacturing device that can directly remove adhesions near the tip of the nozzle, reduce the risk of damaging the tip of the nozzle, and stably manufacture uniform particles.

(1) In order to achieve the above object, the microparticle manufacturing apparatus of the present invention is a microparticle manufacturing apparatus that manufactures microparticles by spraying a solution of raw materials and heating it, and is characterized in that it includes a solution tank that stores the solution, a nozzle that sprays the solution supplied from the solution tank, a furnace tube that heats the sprayed solution to generate microparticles, a recovery device that recovers the generated microparticles, and an adhesion removal mechanism that removes solids that have adhered to the nozzle, and the adhesion removal mechanism includes an edge portion that removes the solids that have adhered to the nozzle by contacting and sliding the edge portion against the solids, and an operating unit that operates the movement of the edge portion, and the edge portion is movable between a standby position that does not interfere with the spraying of the solution from the nozzle and an adhesion removal position that removes adhesion to the nozzle, and the edge portion does not come into contact with the tip of the nozzle at the adhesion removal position.

This allows the adhesion near the tip of the nozzle to be directly removed and reduces the risk of damaging the tip of the nozzle, allowing for the stable production of homogeneous particles. In addition, by moving the edge to a standby position when using the microparticle production device, the formation of adhesion originating from the edge can be prevented.

(2) In addition, in the microparticle manufacturing device of the present invention, the adhesion removal mechanism is characterized by having a reflecting section that reflects the liquid ejected from the nozzle at the adhesion removal position to remove the adhesion. This allows adhesion removal to be performed by utilizing the reflection of the liquid ejected from the nozzle, improving the adhesion removal effect and enabling more stable production of homogeneous particles.

(3) In addition, in the microparticle manufacturing device of the present invention, the reflecting portion is characterized in that the reflecting surface is formed of a curved surface, multiple flat surfaces, or a combination of curved and flat surfaces. This allows the reflection of the liquid ejected from the nozzle to be concentrated on a specific part of the nozzle, further enhancing the effect of removing adhesions.

(4) In addition, in the microparticle manufacturing device of the present invention, the adhesion removal mechanism is characterized by having a nozzle tip protection part that prevents the edge part from contacting the tip part of the nozzle at the adhesion removal position. This allows the edge part or the reflecting part to be brought sufficiently close to the tip part of the nozzle at the adhesion removal position without contacting it.

(5) The microparticle manufacturing apparatus of the present invention further includes a protective tube that protects the nozzle, and at least a portion of the adhesion removal mechanism is disposed within the protective tube. In this way, by disposing at least a portion of the adhesion removal mechanism within the protective tube that protects the nozzle from heat, the adhesion removal mechanism can also be protected from heat, and deformation or damage to the adhesion removal mechanism due to heat can be prevented.

(6) In addition, in the microparticle manufacturing device of the present invention, the operating section is formed in a hollow tube shape through which a heat transfer medium for cooling passes. This makes it possible to protect the adhesion removal mechanism from heat, and to prevent deformation or damage of the adhesion removal mechanism due to heat.

The microparticle manufacturing device of the present invention can directly remove adhesions near the tip of the nozzle and reduce the risk of damaging the tip of the nozzle, allowing for the stable production of homogeneous particles.

1 is a conceptual diagram showing a schematic configuration of a fine particle production apparatus according to an embodiment of the present invention. FIG. 13 is a conceptual diagram showing a schematic configuration of a modified example of the fine particle production apparatus according to the present embodiment. FIG. 13 is a conceptual diagram showing a schematic configuration of a modified example of the fine particle production apparatus according to the present embodiment. FIG. 4 is a front cross-sectional view showing the periphery of an edge portion of the adhesion removal mechanism. 13 is a front cross-sectional view showing the periphery of an edge portion of a modified example of the adhesion removal mechanism for nozzles having different shapes. FIG. 1A to 1D are a front cross-sectional view and a plan view showing a state in which the edge portion is in a standby position and an adhesion removal position, respectively. 13 is a conceptual diagram showing a state in which liquid ejected from a nozzle is reflected by a reflecting portion. FIG. 5A to 5D are cross-sectional views showing examples of the shape of the reflecting portion. 1A to 1C are a plan view, a front view, and a side view, respectively, showing the shape of an adhesion removal mechanism according to an embodiment. FIG. 2 is a cross-sectional view showing an arrangement of a adhesion removal mechanism and a nozzle in the embodiment.

As a result of intensive research, the inventors have discovered that in a microparticle manufacturing device, a sticking removal mechanism for removing solids stuck to a nozzle is composed of an edge part that removes solids by contacting and sliding against solids stuck to the nozzle, and an operating part that operates the movement of the edge part, and the edge part is movable between a standby position that does not interfere with the spraying of the solution from the nozzle and a sticking removal position that removes sticking to the nozzle, and by not contacting the tip of the nozzle in the sticking removal position, it is possible to directly remove sticking near the tip of the nozzle, reduce the risk of damaging the tip of the nozzle, and stably manufacture homogeneous particles, thereby completing the present invention.

That is, the microparticle manufacturing device of the present invention is a microparticle manufacturing device that manufactures microparticles by spraying a solution of raw materials and heating it, and includes a solution tank that stores the solution, a nozzle that sprays the solution supplied from the solution tank, a furnace tube that heats the sprayed solution to generate microparticles, a recovery device that recovers the generated microparticles, and an adhesion removal mechanism that removes solids that have adhered to the nozzle, and the adhesion removal mechanism includes an edge portion that removes the solids that have adhered to the nozzle by contacting and sliding the edge portion against the solids, and an operating portion that operates the movement of the edge portion, and the edge portion is movable between a standby position that does not interfere with the spraying of the solution from the nozzle and an adhesion removal position that removes adhesion to the nozzle, and the edge portion does not come into contact with the tip of the nozzle at the adhesion removal position. Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings.

[Configuration of the fine particle manufacturing apparatus]
1 is a conceptual diagram showing a schematic configuration of a fine particle production apparatus according to the present embodiment. The fine particle production apparatus 1 according to the present embodiment includes a solution tank 10, a nozzle 20, a furnace core tube 30, a recovery device 40, and a adhesion removal mechanism 50.

The solution tank 10 stores a solution of raw materials. The raw materials are compounds containing the elements that make up the product to be synthesized, and are appropriately selected from, for example, inorganic salts, metal alkoxides, metal oxides, etc., depending on the target product to be synthesized. The solvent for dissolving the raw materials is appropriately selected from water, organic solvents, etc., depending on the target product to be synthesized and the raw materials. In addition to the raw materials and solvent, other materials may be added to the raw material solution to adjust the melting temperature, heat resistance, particle strength, etc.

The raw material solution stored in the solution tank 10 is supplied to the nozzle 20 using the pump 12. The pump 12 can adjust the average particle size of the droplets of the sprayed solution by adjusting the pressure, flow rate, mixing ratio, etc. of the solution and compressed air. The average particle size of the droplets of the sprayed solution can also be adjusted by the concentration and viscosity of the solution, and the shape and size of the tip of the nozzle 20 from which the solution is sprayed. The flow rate of the raw material solution supplied to the nozzle 20 can be measured by the flow meter 14.

As described below, when the adhesion removal mechanism 50 includes a reflecting unit 56, it is preferable to include a cleaning tank 16 in addition to the solution tank 10. In this case, when removing adhesion using the reflecting unit 56, the solution tank 10 and the cleaning tank 16 are switched and supplied to the nozzle 20. Alternatively, both the solution tank 10 and the cleaning tank 16 may be connected to the nozzle 20 so that they can be switched. The cleaning liquid stored in the cleaning tank 16 is preferably tap water or distilled water.

The nozzle 20 sprays the solution supplied from the solution tank 10. The nozzle 20 may be a two-fluid nozzle with one solution line and one compressed air line, a three-fluid nozzle with one solution line and two compressed air lines, or a four-fluid nozzle with two solution lines and two compressed air lines. The nozzle 20 is selected according to the target particle size of the microparticles that will become the product, the target production volume, etc.

A nozzle 20 using a resin packing at the tip of the nozzle 20 may be used. As described below, the adhesion removal mechanism 50 of the present invention is structured so that the edge portion 52 does not come into contact with the tip of the nozzle 20. Therefore, even if a nozzle 20 using a resin packing is used, the risk of damaging the packing during adhesion removal can be reduced.

To protect the nozzle 20 from heat, it is preferable to protect the nozzle 20 with a protective tube. It is also more preferable to pass a cooling solvent such as air through the protective tube to reduce heat. This makes it possible to stabilize the spray accuracy of the nozzle 20. Since resin packing may not be resistant to heat, it is particularly effective to use a protective tube in such cases. Note that a heat insulating material may also be used on the outside of the protective tube.

The furnace core tube 30 heats the sprayed droplets of solution to generate fine particles. The sprayed droplets of solution are heated inside the furnace core tube 30, the solvent evaporates, and the solute raw material precipitates. Fine particles of the compound are then generated by thermal decomposition and solid-phase reaction. At this time, part of the sprayed solution adheres to the tip of the nozzle 20 or its vicinity, and the solvent evaporates and solidifies.

The furnace core tube 30 is a passageway of the furnace body of the heating furnace 32, which is made of ceramics, metal, heat-resistant bricks, etc. The furnace core tube 30 may be configured as an externally heated heating furnace 32 having a heating device such as an electric heater or hot air heater inside the wall or on the outer wall side, or as an internally heated heating furnace 32 having a heating device on the inner wall side. It may also be an internal combustion type in which a gas burner or the like is used together with the nozzle 20. Figure 1 shows an externally heated heating furnace 32 heated by a heater 34.

The recovery device 40 recovers the generated fine particles. The recovery of the fine particles is performed by the recovery device 40, which creates a negative pressure inside the furnace core tube 30 using the suction fan 42. The recovery device 40 can be a bag filter, a cyclone powder recovery machine, or the like.

The adhesion removal mechanism 50 removes solids that are adhered to the nozzle 20. The adhesion removal mechanism 50 can be made of metal, ceramic, etc. Details of the adhesion removal mechanism 50 will be described later.

Figures 2 and 3 are conceptual diagrams showing the schematic configuration of a modified example of a microparticle manufacturing device according to this embodiment. Figure 2 shows an example of a microparticle manufacturing device in which the spray direction of the nozzle is downward. The spray direction may also be horizontal or oblique. Figure 3 shows an example of a microparticle manufacturing device that uses an internal combustion heating furnace in which a gas burner 36 is used together with the nozzle. In this way, various configurations of the microparticle manufacturing device are possible.

[Configuration of adhesion removal mechanism]
FIG. 4 is a front cross-sectional view showing the periphery of the edge portion of the adhesion removal mechanism 50. As shown in FIG. 4, the adhesion removal mechanism 50 includes an edge portion 52 and an operation portion 54. The operation portion 54 operates the movement of the edge portion 52. The basic operation of the operation portion 54 is to rotate the end portion of the operation portion 54 around the operation axis. This causes the edge portion 52 to rotate. Note that the operation axis of the operation portion 54 refers to the central axis of the operation portion 54 in the long axis direction, which is arranged approximately parallel to the spray direction of the nozzle 20 or the long axis direction, as shown in FIG. 4. Also, only a portion of the operation portion 54, the nozzle 20, etc. in FIG. 4 are shown.

The edge portion 52 comes into contact with and slides against solid matter adhering to the nozzle 20, thereby removing the solid matter. This allows for direct removal of adhesion near the tip portion 22 of the nozzle 20. The edge portion 52 can come into contact with and slide against the adhering solid matter by rotating the end of the operating portion 54 around the operating axis. Note that the tip portion 22 of the nozzle 20 refers to the part of the spray nozzle that protrudes from one side of the nozzle 20 as shown in Figure 4, but part of the protruding spray nozzle may be recessed.

Figure 5 is a front cross-sectional view showing the periphery of an edge portion of a modified adhesion removal mechanism 50 for a nozzle 20 of a different shape. The adhesion removal mechanism 50 of the shape shown in Figure 5 may rotate and slide the edge portion 52 by rotating the end of the operation unit 54 around an operation axis, but the operation unit 54 may also be operated so that the adhesion removal mechanism 50 itself rotates around the nozzle 20. In this way, the rotation and sliding operations may differ depending on the shape of the adhesion removal mechanism 50. Also, there may be multiple adhesion removal mechanisms 50 as shown in Figure 5.

Figures 6(a) to (d) are front and plan views showing the edge portion 52 in the standby position and adhesion removal position, respectively. As shown in Figures 6(a) to (d), the edge portion 52 can be moved between the standby position ((a) and (b)), which does not prevent the solution from being sprayed from the nozzle 20, and the adhesion removal position ((c) and (d)), which removes adhesion to the nozzle 20. As a result, when the microparticle production device 1 is in use, the edge portion 52 can be moved to the standby position to prevent adhesion from occurring starting from the edge portion 52. This operation can also be performed by rotating the end of the operation portion 54 around the operation axis.

The standby position and the adhesion removal position may each be a predetermined range. That is, the standby position may be a range that does not prevent the solution from being sprayed from the nozzle 20, and the adhesion removal position may be a range in which adhesion of the nozzle 20 is removed. Therefore, the standby position is not limited to a position rotated 180 degrees from the adhesion removal position as shown in FIG. 6(b), but may be, for example, a range from a position rotated 90 degrees to a position rotated 270 degrees from the adhesion removal position. Also, the adhesion removal position is not limited to a position in which the edge portion 52 is directly above the tip portion 22 of the nozzle 20 as shown in FIG. 6(d), but may be, for example, a range in which the edge portion 52 slides.

The edge portion 52 does not contact the tip portion 22 of the nozzle 20 at the adhesion removal position. This reduces the risk of damaging the tip portion 22 of the nozzle 20, and allows for the stable production of homogeneous particles. The reason why adhesion near the tip portion 22 can be removed by sliding even though the edge portion 52 does not contact the tip portion 22 of the nozzle 20 is because the adhesion near the tip portion 22 gradually grows in the spray direction of the solution. The adhesion that has grown in this way is scraped out and removed by the edge portion 52 by sliding the edge portion 52, which is sufficiently close to the tip portion 22 without contacting it. The distance between the edge portion 52 and the tip portion 22 of the nozzle 20 is preferably 5 mm or less, and more preferably 3 mm or less. There is no particular lower limit to the distance as long as there is no contact, but it is preferable to set it to, for example, 1 mm or more in order to control it with a margin for the purpose of protecting the tip portion 22 of the nozzle 20.

As a configuration for preventing the edge portion 52 from coming into contact with the tip portion 22 of the nozzle 20, for example, a nozzle tip protection portion 58 described below may be provided, but in addition, the movable range of the adhesion removal mechanism 50 may be limited to only rotation around the operating axis of the operating portion 54.

The adhesion removal mechanism 50 preferably includes a reflecting portion 56 that reflects the liquid ejected from the nozzle 20 at the adhesion removal position of the nozzle 20 to remove adhesion. This allows the reflection of the liquid ejected from the nozzle 20 to be used to remove adhesion, increasing the adhesion removal effect and allowing homogeneous particles to be produced more stably. FIG. 7 is a conceptual diagram showing the state in which the liquid ejected from the nozzle 20 is reflected by the reflecting portion 56. As shown in FIG. 7, by reflecting the liquid ejected from the nozzle 20 by the reflecting portion 56, adhesion at the tip 22 of the nozzle 20 and its vicinity can be more reliably removed. Note that the ejection of the liquid from the nozzle 20 for adhesion removal may be performed under different conditions, such as the type, pressure, and flow rate of the ejected liquid, from the spraying of the solution for producing fine particles.

It is preferable that the reflecting surface of the reflecting portion 56 is formed of a curved surface, multiple flat surfaces, or a combination of curved and flat surfaces. This allows the reflection of the liquid ejected from the nozzle to be concentrated on a specific part of the nozzle, further enhancing the effect of removing adhesion. Figures 8(a) to (d) are cross-sectional views showing examples of the shape of the reflecting portion 56. In the example shown in Figures 8(a) to (d), the edge portion 52 and the reflecting portion 56 are formed integrally, but they may be formed separately, or the edge portion 52 and the reflecting portion 56 may be formed in different parts of the adhesion removal mechanism 50. In addition, in Figures 7 and 8, the operating portion 54 that connects the reflecting portion 56 is formed of a tubular member, but this portion may have any shape, and for example, a plate-shaped member, a solid columnar member, etc. may be used.

It is preferable that the adhesion removal mechanism 50 is provided with a nozzle tip protection part 58 that prevents the edge part 52 from contacting the tip part 22 of the nozzle 20 at the adhesion removal position. This allows the edge part 52 or the reflecting part 56 to be brought sufficiently close to the tip part 22 of the nozzle 20 without contacting the tip part 22 of the nozzle 20 at the adhesion removal position. When the edge part 52 and the reflecting part 56 are integrally formed, the nozzle tip protection part 58 can prevent not only the edge part 52 but also the reflecting part 56 from contacting the tip part 22 of the nozzle 20. When the edge part 52 and the reflecting part 56 are formed at different positions of the adhesion removal mechanism 50, it is preferable that the nozzle tip protection part 58 has both a nozzle tip protection part for preventing the edge part 52 from contacting the tip part 22 of the nozzle 20 and a nozzle tip protection part for preventing the reflecting part 56 from contacting the tip part 22 of the nozzle 20. In addition, it is preferable that the surface of the nozzle tip protection part 58 that contacts the nozzle 20 is a convex curved surface on a circular arc. This allows smooth rotation of the adhesion removal mechanism 50 around the operating axis.

When the adhesion removal mechanism 50 is equipped with a nozzle tip protection part 58, the operation of the adhesion removal mechanism 50 does not have to be limited to rotation around the operation axis, and since the edge part 52 will not come into contact with the tip part 22 of the nozzle 20 at the adhesion removal position, it may be configured to be able to move within a predetermined range in the operation axis direction. With such a configuration, it is possible to form a shape in which the edge part 52 or the reflecting part 56 may come into contact with the tip part 22 of the nozzle 20 by rotation around the operation axis alone. For example, it is possible to form the shape of the reflecting surface of the reflecting part 56 as a curved surface, while bringing the reflecting surface closer to the tip part 22 of the nozzle 20.

The microparticle manufacturing device 1 further includes a protective tube 60 that protects the nozzle 20, and it is preferable that at least a portion of the adhesion removal mechanism 50 is disposed within the protective tube 60. In this way, by disposing at least a portion of the adhesion removal mechanism 50 within the protective tube 60 that protects the nozzle 20 from heat, the adhesion removal mechanism 50 can also be protected from heat, and deformation or damage of the adhesion removal mechanism 50 due to heat can be prevented. If the adhesion removal mechanism 50 is deformed or damaged due to heat, there is a risk that the tip 22 of the nozzle 20 will be damaged during adhesion removal.

The operating unit 54 is preferably formed as a hollow tube through which a heat transfer medium for cooling passes. This can protect the adhesion removal mechanism 50 from heat, and can prevent deformation or damage of the adhesion removal mechanism 50 due to heat. Air, water, etc. can be used as the heat transfer medium for cooling. When air is used, it can be released directly into the furnace core tube 30, and the structure of the operating unit 54 can be simplified. When a liquid such as water is used, the cooling effect can be increased. When a liquid such as water is used, it is preferable to return the liquid to the outside of the furnace core tube 30 or to circulate the liquid rather than releasing it into the furnace core tube 30.

[Example]
9A to 9C are a plan view, a front view, and a side view, respectively, showing the shape of the adhesion removal mechanism of the embodiment. In addition, in FIG. 9B and FIG. 9C, the length of the operation part of the adhesion removal mechanism in the longitudinal direction is omitted. The adhesion removal mechanism of the embodiment was manufactured by using a pipe and a plate-shaped member made of SUS316L and processing them into the shape shown in FIG. 9. The adhesion removal mechanism of the embodiment was manufactured to match the shape of the nozzle used in the following demonstration so that the lower end of the edge part passes a position 3 mm away from the tip of the nozzle when rotated.

The effectiveness of the adhesion removal mechanism of the embodiment was demonstrated using the spray pyrolysis device shown in Figure 3. A three-fluid nozzle with a resin packing at the spray nozzle was installed at the bottom of the combustion tube (furnace core tube), and the adhesion removal mechanism was inserted and installed in parallel with the three-fluid nozzle. Figure 10 is a cross-sectional view showing the arrangement of the adhesion removal mechanism and nozzle of the embodiment. As shown in Figure 10, the adhesion removal mechanism was installed inside a protective tube provided around the nozzle, and cooling air was introduced into the protective tube to protect the nozzle and adhesion removal mechanism. Insulation material was also placed on the outer surface of the protective tube. A gas burner was used as the heat source for heating the compound. The adhesion removal mechanism was also held by the underside of the protective tube.

Next, a mixed aqueous solution of aluminum and silicon was prepared by dissolving 0.04 mol of aluminum nitrate and 0.16 mol of tetraethyl orthosilicate in 1 liter of distilled water, and was poured into the solution tank. The poured aqueous solution was then sprayed into a mist form through a three-fluid nozzle using a pump, and passed through a reaction section (furnace tube) with an internal temperature of 1000°C. The particles were then collected using a collection device (bag filter).

The spraying time was 6 hours in total, and the condition of the nozzle tip was compared when the adhesion removal mechanism was not used and when the mechanism was moved to the adhesion removal position after 3 minutes had passed after switching from the raw solution to the cleaning solution (distilled water) every hour and the mechanism was slid for 30 seconds. As a result, adhesion was confirmed at the nozzle tip when the adhesion removal mechanism was not used. In contrast, no adhesion was confirmed when the adhesion removal mechanism was operated every hour. Furthermore, no defects such as scratches were found at the nozzle tip when the adhesion removal mechanism was operated every hour.

From the above results, the microparticle manufacturing device of the present invention is capable of directly removing adhesions near the tip of the nozzle, while reducing the risk of damaging the tip of the nozzle, and is capable of stably manufacturing homogeneous particles.

Reference Signs List 1 Fine particle manufacturing device 10 Solution tank 12 Pump 14 Flow meter 16 Cleaning tank 20 Nozzle 22 Tip portion 30 Furnace core tube 32 Heating furnace 34 Heater 36 Gas burner 40 Recovery device 42 Suction fan 50 Adhesion removal mechanism 52 Edge portion 54 Operation portion 56 Reflection portion 58 Nozzle tip protection portion 60 Protection tube

Claims (6)

A microparticle manufacturing apparatus for manufacturing microparticles by spraying a raw material solution and heating the solution,
A solution tank for storing the solution;
a nozzle for spraying the solution supplied from the solution tank;
a furnace core tube for heating the atomized solution to generate fine particles;
A recovery device for recovering the generated fine particles;
a solid removal mechanism for removing solid matter adhering to the nozzle,
the adhesion removal mechanism includes an edge portion that comes into contact with and slides against a solid object adhered to the nozzle to remove the solid object, and an operation portion that operates a movement of the edge portion;
the edge portion is movable between a standby position where the edge portion does not hinder the spraying of the solution from the nozzle and an adhesion removal position where the edge portion removes adhesion of the nozzle;
The apparatus for producing fine particles, wherein the edge portion does not contact the tip portion of the nozzle at the adhesion removal position. The microparticle manufacturing device according to claim 1, characterized in that the adhesion removal mechanism includes a reflecting section that removes the adhesion by reflecting the liquid ejected from the nozzle at the adhesion removal position. The microparticle manufacturing device according to claim 2, characterized in that the reflecting surface of the reflecting section is formed as a curved surface, a plurality of flat surfaces, or a combination of curved and flat surfaces. The microparticle manufacturing device according to any one of claims 1 to 3, characterized in that the adhesion removal mechanism is provided with a nozzle tip protection part that prevents the edge part from contacting the tip part of the nozzle at the adhesion removal position. The microparticle manufacturing apparatus further includes a protective tube for protecting the nozzle,
5. The apparatus for producing fine particles according to claim 1, wherein at least a portion of the adhesion removal mechanism is disposed inside the protective tube. The microparticle manufacturing device according to any one of claims 1 to 5, characterized in that the operating section is formed in a hollow tube shape through which a heat transfer medium for cooling passes.

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