Fluid nozzle

Abstract

To provide a fluid nozzle that can suppress adhered substances from depositing at a peripheral edge part of a discharge port, so that microparticles can be manufactured over a long period of time.SOLUTION: A fluid nozzle is provided with: a fluid nozzle main body which has a discharge port in a planar shape which is a horizontally long square, which is constituted of a liquid discharge port that discharges liquid and gas discharge ports formed adjacent to both ends of the liquid discharge port; and a gas introduction pipe provided along a height direction of an outer periphery of the fluid nozzle main body and bent through a bending part toward a short side of the discharge port, which sprays gas from a gas discharge port at a tip thereof toward the short side of the discharge port of the fluid nozzle.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fluid nozzle. [Background technology]

[0002] As an apparatus for producing fine particles, for example, there is a spray pyrolysis apparatus or a spray drying apparatus. In these apparatuses, a fluid nozzle is installed, and a raw material solution is discharged from a liquid discharge port of the fluid nozzle into a heating furnace to form a mist, and the mist is dried or pyrolyzed to produce fine particles. For example, a two-fluid nozzle or a three-fluid nozzle is used as the fluid nozzle (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-25385 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the inventors produced fine particles by ejecting a raw material solution from a three-fluid nozzle having an ejection port with a horizontally elongated rectangular planar shape, they found that, as shown in Fig. 9, deposits gradually precipitated and grew large around the periphery of the ejection port, particularly on the short side of the ejection port, and it became impossible to obtain fine particles having the desired particle size. As a result, cleaning to remove the deposits was unavoidable, making it difficult to continue producing fine particles for a long period of time. An object of the present invention is to provide a fluid nozzle capable of suppressing deposition of solidified matter around the discharge port and producing fine particles over a long period of time. [Means for solving the problem]

[0005] In order to clarify the cause of deposition of the solid matter on the periphery of the discharge port, particularly on the short side of the discharge port, the inventors conducted various studies using a three-fluid nozzle 20 having a horizontally elongated rectangular planar shape of the discharge port as shown in FIG. 8. As a result, the following findings were obtained. That is, in the case of the three-fluid nozzle 20, since the gas discharge port 2 is provided adjacent to the long side of the liquid discharge port 1, the short side 4 of the discharge port is affected by the raw material solution discharged from the liquid discharge port 1 and the gas discharged from the gas discharge port 2, as shown in FIG. 8, and a flow that draws in a part of the mist 8 is generated. Therefore, a part of the mist 8 of the raw material solution discharged from the liquid discharge port 1 adheres to the short side 4 of the discharge port, and at the same time, the moisture of the adhered mist evaporates due to heating, and a solid matter is deposited. Then, the adhesion of the mist and the deposition of the solid matter are repeated on the short side 4 of the discharge port, so that the solid matter grows large, which hinders the formation of a good mist and makes it impossible to obtain fine particles having a desired particle diameter.

[0006] Therefore, the inventors have found that by installing a gas introduction pipe along the height direction (vertical direction) of the outer periphery of the three-fluid nozzle body, which has a horizontally elongated rectangular shape in plan view, bending the gas outlet at the tip of the gas introduction pipe via a bending part so that it faces the short side of the discharge port, and blowing gas from the gas outlet toward the short side of the discharge port, the entrainment of mist is suppressed, the mist is less likely to adhere to the periphery of the discharge port, and precipitation of solidified matter is suppressed, so that fine particles having a desired particle size can be produced for a long period of time. Here, in this specification, "mist" refers to fine particles of liquid dispersed in a gas, in other words, a misty liquid.

[0007] That is, the present invention provides the following [1] to [6]. [1] A fluid nozzle body having a discharge port having a horizontally elongated rectangular shape in a plan view, the discharge port being composed of a liquid discharge port for discharging a liquid and a gas discharge port adjacent to both ends of the liquid discharge port; A gas introduction pipe that is provided along the height direction of the outer periphery of the fluid nozzle body and is bent toward the short side of the discharge port via a bent portion, and that blows gas from a gas discharge port at the tip toward the short side of the discharge port of the fluid nozzle. A fluid nozzle comprising: [2] The fluid nozzle according to [1] above, wherein the gas discharge port of the gas inlet pipe has a swirling mechanism for blowing a swirling air current toward the short side of the discharge port. [3] The fluid nozzle according to [1] or [2] above, wherein the rotation mechanism is a plate unit. [4] The fluid nozzle according to any one of [1] to [3] above, wherein the gas introduction pipe is installed as any one of the following (1) to (3), or a combination of two or more of these: (1) One or more sets of gas introduction pipes are installed symmetrically with respect to the center line in the longitudinal direction of the discharge port. (2) One or more sets of gas introduction pipes are installed symmetrically with respect to the center line in the short direction of the discharge port. (3) One or more pairs of gas introduction pipes are installed diagonally around the intersection of the center line of the discharge port in the longitudinal direction and the center line of the discharge port in the lateral direction. [5] The fluid nozzle according to any one of [1] to [4] above, wherein the gas introduction pipe is bent at an angle between 30° upward and 60° downward with respect to the horizontal direction via a bending portion so that the gas exhaust port faces the short side of the discharge port. [6] A fluid nozzle that ejects a raw material solution; A heating furnace that dries or pyrolyzes the mist of raw material solution discharged from a fluid nozzle Equipped with The fluid nozzle is the fluid nozzle described in any one of [1] to [5] above. Spray drying equipment or spray pyrolysis equipment. Effect of the Invention

[0008] According to the present invention, since deposition of solid matter around the discharge port can be suppressed, a fluid nozzle capable of producing fine particles for a long period of time can be provided. Furthermore, by mounting the fluid nozzle of the present invention on a spray drying device or a spray pyrolysis device, fine particles having a desired particle size can be produced for a long period of time. [Brief description of the drawings]

[0009] [Figure 1]1 is a schematic diagram illustrating one embodiment of a fluid nozzle of the present invention. [Diagram 2] 1 is a schematic diagram showing an example of a rotation mechanism of a gas introduction tube in a fluid nozzle of the present invention. FIG. [Diagram 3] FIG. 4 is a plan view showing an example of an installation position of a gas introduction pipe in the fluid nozzle of the present invention. [Figure 4] FIG. 4 is a plan view showing an example of an installation position of a gas introduction pipe in the fluid nozzle of the present invention. [Diagram 5] FIG. 4 is a plan view showing an example of an installation position of a gas introduction pipe in the fluid nozzle of the present invention. [Figure 6] FIG. 4 is a plan view showing an example of an installation angle of a gas introduction pipe in the fluid nozzle of the present invention. [Figure 7] FIG. 1 is a schematic diagram showing one embodiment of a spray drying apparatus or a spray pyrolysis apparatus equipped with a fluid nozzle of the present invention. [Figure 8] FIG. 1 is a schematic diagram showing an example of a conventional fluid nozzle. [Figure 9] 1 is a diagram showing an example of deposition of a solid substance on the peripheral edge of an ejection port of a fluid nozzle; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated descriptions will be omitted. In addition, for convenience of illustration, the dimensional ratios of the drawings do not necessarily match those in the description.

[0011] An embodiment of a fluid nozzle of the present invention is shown in Fig. 1. Fig. 1(a) is a schematic plan view, and (b) is a schematic cross-sectional view. A preferred embodiment will be described below with reference to the drawings. The fluid nozzle 11 shown in FIG. 1 is cylindrical in shape. The liquid outlet 1 is provided at approximately the center of the center edge 6, and the gas outlet 2 is provided adjacent to both ends of the long side (longitudinal direction) of the liquid outlet 1. The center edge 6 is provided with a liquid line (not shown) for supplying liquid to the liquid outlet 1 and a gas line (not shown) for supplying gas to the gas outlet 2. Side blocks 7 are provided at both ends of the center edge 6 via packings 5. A protrusion 3 for guiding the discharge direction of mist 8 is provided on the upper surface of the side block 7. The gas introduction pipe 9 has a gas discharge port 10 at its tip bent toward the protrusion 3 on the short side of the outlet via a bent portion.

[0012] The nozzle is composed of one liquid nozzle 1 and two gas nozzles 2, and has a horizontally long rectangular shape in plan view as shown in FIG. 1. In this specification, the term "planar shape" refers to the shape of the entire fluid nozzle when viewed from directly above, and the term "horizontally long rectangular shape" refers to a rectangle whose horizontal direction is longer than its vertical direction. By using such a shape, the amount of liquid sprayed can be easily increased without changing the particle size of the mist. Therefore, the size of the liquid nozzle 1 can be appropriately selected in consideration of the amount of liquid sprayed, nozzle strength, etc., according to the size of the fluid nozzle.

[0013] The horizontally elongated rectangle is not particularly limited as long as it is a plane figure surrounded by four points and four line segments connecting them, and has sides that are longer in the horizontal direction than in the vertical direction. For example, a rectangle, a parallelogram, a trapezoid, and a rectangle whose four sides are different in length can be mentioned. Among them, a rectangle and a parallelogram are preferable, and a rectangle is more preferable. The corners of the plane rectangle may be angular or rounded. The size of the horizontally elongated rectangle constituting the discharge port can be appropriately selected depending on the size of the fluid nozzle, etc.

[0014] The liquid flow rate of the liquid outlet can be appropriately selected depending on the size of the fluid nozzle, etc., but from the standpoint of increasing the production of fine particles and making the mist particle size approximately uniform, it is preferably 3 L / h or more, more preferably 6 L / h or more, even more preferably 12 L / h or more, and preferably 200 L / h or less, more preferably 150 L / h or less, and even more preferably 130 L / h or less. The pressure of the liquid supplied to the liquid ejection port can be appropriately selected depending on the size of the fluid nozzle and the liquid flow rate, but from the viewpoint of achieving approximately uniform particle size of the mist, it is preferably 0.03 MPa or more, more preferably 0.10 MPa or more, even more preferably 0.15 MPa or more, and is preferably 1.40 MPa or less, more preferably 1.00 MPa or less, and even more preferably 0.60 MPa or less.

[0015] The gas outlet ejects the gas supplied from the gas supply unit through the gas line toward the liquid ejected from the liquid outlet 1. As a result, the gas ejected from the gas outlet 2 collides with the liquid ejected from the liquid outlet 1 and disperses, forming a mist.

[0016] Examples of the gas supplied to the gas outlet include air and inert gases such as nitrogen and argon. Among these, air is preferred from the viewpoint of economy.

[0017] From the viewpoint of making the mist particle size approximately uniform, the gas flow rate of the gas outlet is preferably 200 L / min or more, more preferably 250 L / min or more, even more preferably 400 L / min or more, and is preferably 3000 L / min or less, more preferably 1500 L / min or less, and even more preferably 1000 L / min or less. The gas flow rate is the sum of the gas flow rates discharged from all the gas outlets. The pressure of the gas supplied to the gas outlet can be appropriately selected depending on the size of the fluid nozzle and the gas flow rate, but from the viewpoint of achieving approximately uniform particle size of the mist, it is preferably 0.1 MPa or more, more preferably 0.35 MPa or more, even more preferably 0.5 MPa or more, and is preferably 2.40 MPa or less, more preferably 1.30 MPa or less, and even more preferably 0.85 MPa or less.

[0018] 1, the gas introduction pipe 9 is provided along the height direction (vertical direction) of the outer periphery of the fluid nozzle body, and is bent at a bent portion so that the gas exhaust port 10 faces the short side of the discharge port. This allows gas to be blown from the gas exhaust port 10 at the tip toward the short side of the discharge port, suppressing the entrainment of mist, making it difficult for mist to adhere to the periphery of the discharge port, and suppressing the occurrence of solidified matter.

[0019] The size of the gas inlet pipe can be appropriately selected taking into consideration the size and strength of the fluid nozzle, etc. The outer diameter (width) of the gas outlet of the gas inlet pipe can be approximately equal to the length (width) of the short side of the outlet from the viewpoint of preventing adhesion of mist and suppressing the generation of solidified matter. The cross-sectional shape of the gas outlet of the gas inlet pipe is not particularly limited, but may be, for example, a circle, an ellipse, or a rectangle. Examples of the rectangle include, but are not limited to, a square, a rectangle, a parallelogram, and a trapezoid.

[0020] A swirling mechanism for blowing a swirling air current toward the short side of the outlet may be provided at the gas outlet of the gas inlet pipe. By blowing the gas in such a swirling state, it is possible to further suppress the adhesion of mist and the occurrence of solidified matter, and it is also possible to obtain the effect of making the particle size of the mist approximately uniform. The swirling mechanism is not particularly limited as long as it can swirl the gas discharged from the gas outlet, and may be, for example, a plate unit. Here, in this specification, the term "plate unit" refers to a unit composed of one or more plate-shaped bodies, and may be a unit formed from a single plate-shaped body.

[0021] The shape of the plate-like body can be appropriately selected from a range of shapes, including rectangular, circular, elliptical, tapered, and arched shapes. The material of the plate-like body is not particularly limited and may be metal or ceramic. The size of the plate-like body can be appropriately selected depending on the size of the gas exhaust port, etc., so that a swirling air current is generated. One or more plate units can be installed inside the gas exhaust port. The installation position of the plate unit can be appropriately set, but is usually at the end of the gas exhaust port.

[0022] The number of plates to be installed can be appropriately selected depending on the size of the gas exhaust port, etc., but since the more the number of plates, the narrower the dimension between the plates and the higher the gas discharge flow rate, 2 or more plates are preferable, 4 or more plates are more preferable, and 4 to 8 plates are even more preferable. When configured with multiple plates, for example, the plates may be fixed to a central axis or may be rotatable.

[0023] The installation angle of the plate-like body can be selected appropriately as long as the gas discharged from the gas exhaust port can be made to swirl, but from the viewpoint of preventing mist adhesion and suppressing the generation of solidified matter, it is preferable to incline the plate-like body at an angle of 10 to 60° with respect to the cross section of the gas exhaust port (a plane perpendicular to the exhaust direction), and more preferably at an angle of 15 to 45°. A preferred embodiment is a plate unit in which a plurality of plates are arranged at equal intervals around an axis, with opposing plates being inclined in opposite directions at the above-mentioned angle.

[0024] Specific examples of the plate unit are shown in Figures 2(a) to 2(d). The plate unit shown in Figure 2 has four plates arranged evenly around the axis, and two opposing pairs of plates are inclined in opposite directions at angles of 15 to 45 degrees with respect to the cross section of the gas exhaust port (a plane perpendicular to the exhaust direction).

[0025] The position of the gas introduction pipe is not particularly limited as long as it can prevent the mist from adhering to the periphery of the discharge port and suppress the generation of solidified matter, but any of the following (1) to (3) or a combination of two or more of these is preferable. By adopting such an embodiment, it is possible to further enhance the prevention of the mist from adhering and the suppression of the generation of solidified matter. (1) One or more sets of gas introduction pipes are installed symmetrically with respect to the center line in the longitudinal direction of the discharge port. (2) One or more sets of gas introduction pipes are installed symmetrically with respect to the center line in the short direction of the discharge port. (3) One or more pairs of gas introduction pipes are installed diagonally around the intersection of the center line of the discharge port in the longitudinal direction and the center line of the discharge port in the lateral direction.

[0026] The location of the gas introduction pipe will now be specifically described. FIG. 3 shows an example of the above-mentioned embodiment (1), that is, one or more sets of gas introduction pipes 9 are installed symmetrically with respect to the center line in the longitudinal direction of the discharge port. Here, "the center line in the longitudinal direction of the discharge port" means a line connecting the midpoints of two long sides in a discharge port composed of one liquid discharge port 1 and two gas discharge ports 2, and "installed symmetrically with respect to the center line" means that they are installed at positions that are line symmetric. In the gas introduction pipes shown in (a) to (c) of FIG. 3, one set of gas introduction pipes 9 is installed line symmetrically with respect to the center line in the longitudinal direction of the discharge port. In addition, in the gas introduction pipes shown in (d) to (e) of FIG. 3, three sets of gas introduction pipes 9 are installed line symmetrically with respect to the center line in the longitudinal direction of the discharge port.

[0027] Fig. 4 shows an example of the above-mentioned embodiment (2), that is, one or more sets of gas introduction pipes 9 are installed symmetrically with respect to the center line in the short side direction of the discharge port. Here, "center line in the short side direction of the discharge port" means a line connecting the midpoints of two short sides in a discharge port composed of one liquid discharge port 1 and two gas discharge ports 2, and "installed symmetrically with respect to the center line" means installed at positions that are line symmetric. In the gas introduction pipes shown in Fig. 4(a)-(b), two sets of gas introduction pipes 9 are installed line symmetrically with respect to the center line in the short side direction of the discharge port.

[0028] Fig. 5 shows an example of the above-mentioned embodiment (3), that is, one or more sets of gas introduction pipes are installed diagonally around the intersection of the center line of the discharge port in the longitudinal direction and the center line of the discharge port in the lateral direction. Here, "installed diagonally around the intersection with the center line" means that they are installed at positions that are point symmetric. In the gas introduction pipes shown in Fig. 5 (a) to (d), one set of gas introduction pipes 9 is installed point symmetrically, and in the gas introduction pipes shown in Fig. 5 (e) to (f), two sets of gas introduction pipes 9 are installed point symmetrically.

[0029] The gas introduction pipe is preferably bent at an angle between 30° upward and 60° downward with respect to the horizontal direction via the bend so that the gas exhaust port faces the short side of the discharge port. This allows for a stronger gas blow to the peripheral area of ​​the discharge port, making it difficult for mist to adhere to the peripheral area of ​​the discharge port and suppressing the occurrence of solidified matter. The "horizontal direction" here refers to the direction parallel to the top surface of the discharge port. The gas introduction pipe extending in the vertical direction (up and down direction) along the fluid nozzle body has a structure in which it is bent toward the short side of the discharge port via a bent portion, and in the case where the gas discharge port 10 of the gas introduction pipe 9 has a structure in which it is bent so as to face a parallel direction in contact with the upper surface of the protrusion via a bent portion as shown in (a) of FIG. 6, the angle is set to 0°. In addition, "30° upward" refers to a structure in which the gas discharge port 10 of the gas introduction pipe 9 has a bent portion so as to face a direction inclined 30° upward with respect to the horizontal direction as shown in (b) of FIG. 6. In addition, "60° downward" refers to a structure in which the gas discharge port 10 of the gas introduction pipe 9 has a bent portion so as to face a direction inclined 60° downward with respect to the horizontal direction parallel to the upper surface of the discharge port as shown in (c) of FIG. 6.

[0030] From the viewpoint of preventing mist adhesion and suppressing the generation of solidified matter, the inclination angle of the bent portion of the gas introduction pipe is preferably in the range of 25° upward to 55° downward with respect to the horizontal direction, more preferably in the range of 20° upward to 50° downward, and even more preferably in the range of 15° upward to 45° downward. By blowing the gas at such an angle, not only can the adhesion of mist and the generation of solidified matter be further prevented, but even if the adhesion of mist or the precipitation of solidified matter occurs, the blown gas can blow away and remove the adhered mist and solidified matter.

[0031] From the viewpoint of preventing mist adhesion and suppressing the generation of solidified matter, the distance between the gas exhaust port end of the gas inlet pipe and the short side end of the discharge port is preferably 0.5 mm or more, more preferably 2.0 mm or more, even more preferably 5.0 mm or more, and preferably 50 mm or less, more preferably 30 mm or less, and even more preferably 50 mm or less. In the fluid nozzle shown in Fig. 1, the distance between the gas exhaust port of the gas inlet pipe and the short side end of the discharge port refers to the distance between the gas exhaust port of the gas inlet pipe and the outer end of the protrusion.

[0032] In particular, from the viewpoint of preventing the adhesion of mist and suppressing the generation of solidified matter, it is preferable to provide a swirl mechanism at the gas exhaust port of the gas inlet pipe, and it is even more preferable to provide a swirl mechanism at the gas exhaust port and then adjust the distance between the end of the gas exhaust port of the gas inlet pipe and the end of the short side of the discharge port to 30 mm or less.

[0033] Examples of the gas to be supplied to the gas introduction pipe include air, nitrogen, argon, and other inert gases. Among these, air is preferred from the viewpoint of economic efficiency. The gas may be supplied to the gas introduction pipe either intermittently or continuously, but it is preferred to supply the gas continuously from the viewpoint of preventing the adhesion of mist and suppressing the generation of solidified matter.

[0034] The ratio of the sum of the cross-sectional areas of the gas exhaust ports of the gas inlet tube to the sum of the cross-sectional areas of the gas exhaust ports of the fluid nozzle is preferably 0.1 or more, more preferably 0.5 or more, and even more preferably 1.0 or more, from the viewpoint of preventing mist adhesion and suppressing the occurrence of solidified matter, and is preferably 15.0 or less, more preferably 10.0 or less, and even more preferably 5.0 or less.

[0035] The ratio of the sum of the gas flow rates of the gas exhaust ports of the gas inlet tube to the sum of the gas flow rates of the gas exhaust ports of the fluid nozzle is preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, from the viewpoint of preventing mist adhesion and suppressing the occurrence of solidified matter, and is preferably 10.0 or less, more preferably 5.0 or less, and even more preferably 3.0 or less.

[0036] The ratio of the gas discharge speed from the gas exhaust port of the gas inlet tube to the gas discharge speed from the gas exhaust port of the fluid nozzle is preferably 0.3 or more, more preferably 0.5 or more, and even more preferably 1.0 or more, from the viewpoint of preventing mist adhesion and suppressing the occurrence of solidified matter, and is preferably 30.0 or less, more preferably 10.0 or less, and even more preferably 5.0 or less.

[0037] The gas supplied to the gas inlet pipe is preferably compressed. The gas pressure can be appropriately selected depending on the size of the gas inlet pipe and the gas flow rate, but from the viewpoint of preventing adhesion of mist and suppressing generation of solidified matter, it is preferably 0.3 MPa or more, more preferably 0.4 MPa or more, even more preferably 0.5 MPa or more, and is preferably 2.4 MPa or less, more preferably 1.3 MPa or less, and even more preferably 0.85 MPa or less.

[0038] The temperature of the gas discharged from the gas outlet of the gas inlet pipe may be room temperature or heated, but from the viewpoint of preventing mist adhesion and suppressing the generation of fixed matter, it is preferable that the gas is heated. From the viewpoint of preventing mist adhesion and suppressing the generation of fixed matter, the temperature of the heated gas is preferably 20°C or higher, more preferably 50°C or higher, and even more preferably 80°C or higher, and is preferably 350°C or lower, more preferably 250°C or lower, and even more preferably 150°C or lower.

[0039] The size of the fluid nozzle body is not particularly limited and can be appropriately selected in consideration of the amount of liquid sprayed, the nozzle strength, etc. For example, the length of the fluid nozzle body is, for example, 400 to 1500 mm, and the outer diameter of the nozzle body is φ40 to 80 mm when the nozzle is cylindrical.

[0040] The fluid nozzle may be of an internal mixing type in which the liquid and air are mixed inside the nozzle, or an external mixing type in which the liquid and air are mixed outside the nozzle, but the external mixing type is preferred in that the effects of the present invention can be more easily obtained. The fluid nozzle of the present invention is useful as a fluid nozzle to be attached to a spray drying apparatus or a spray pyrolysis apparatus described below.

[0041] [Spray drying equipment or spray pyrolysis equipment] The spray pyrolysis apparatus or spray drying apparatus of the present invention is equipped with the fluid nozzle of the present invention. A preferred embodiment will be described below with reference to FIG.

[0042] FIG. 7 is a schematic diagram showing an example of the spray drying apparatus or spray pyrolysis apparatus of the present invention. As shown in FIG. 7, the spray pyrolysis apparatus or spray drying apparatus 100 includes a fluid nozzle 11 for spraying the raw material solution in a heating furnace 31, and a heating device 32 for heating the mist formed from the raw material solution to dry or pyrolyze it.

[0043] The fluid nozzle is not particularly limited as long as it is the fluid nozzle of the present invention. The specific embodiment of the nozzle is as described above. Although it is possible to install one or more fluid nozzles, the device shown in FIG. 7 is installed with one nozzle.

[0044] The outer periphery of the fluid nozzle may be covered with a heat insulating material 33. Examples of the heat insulating material include ceramic fiber, glass fiber, castable, and the like.

[0045] The material of the heating furnace 31 is not particularly limited as long as it is used as a furnace material, but examples of the material include heat-resistant metals such as iron, stainless steel, Inconel, Hastelloy, titanium, ceramics, bricks, and amorphous refractories. The shape of the heating furnace 31 can be appropriately selected, but may be, for example, a substantially cylindrical shape. The size of the heating furnace 31 can be appropriately selected depending on the production scale. For example, when it is a vertical cylindrical furnace, the inner diameter is preferably 600 to 1600 mm, and the height is preferably 3000 to 10000 mm.

[0046] The heating device 32 is not particularly limited as long as it can provide the amount of heat required for drying or thermal decomposition of the mist of the raw material solution, and examples thereof include a combustion burner, a hot air heater, an electric heater, etc. One or more heating devices 12 can be installed. The device shown in FIG. 7 is installed with eight heating devices. Note that any of the combustion burners, hot air heaters, and electric heaters can be used as long as they are generally commercially available.

[0047] Next, a method for producing fine particles using a spray drying apparatus or a spray pyrolysis apparatus will be described, but as a preferred embodiment, a method for producing inorganic oxide particles will be described.

[0048] First, a raw material solution is prepared. The raw material solution is, for example, a solution of a compound containing an element that constitutes an oxide, and is prepared by mixing the raw material compound with a solvent. Examples of the solvent include water and organic solvents. Among them, water is preferred from the viewpoints of the impact on the environment and the production cost. The raw material compound is not particularly limited as long as it contains an element constituting an inorganic oxide and is soluble in water, and examples thereof include inorganic salts, organic salts, alkoxides, etc. Examples of inorganic salts include nitrates, sulfates, carbonates, hydroxides, and halides. Examples of organic salts include formates, acetates, propionates, oxalates, and citrates.

[0049] Examples of elements constituting the inorganic oxide include one or more elements selected from the group 1 elements of the periodic table, group 2 elements of the periodic table, group 4 elements of the periodic table, group 8 elements of the periodic table, group 9 elements of the periodic table, group 10 elements of the periodic table, group 11 elements of the periodic table, group 12 elements of the periodic table, group 13 elements of the periodic table, group 14 elements of the periodic table, and group 15 elements of the periodic table.

[0050] Specific examples of the raw material compounds include the following: Examples of raw material compounds containing Group 1 elements of the periodic table include sodium compounds such as sodium nitrate, sodium chloride, sodium hydroxide, and sodium sulfate, and potassium compounds such as potassium nitrate, potassium chloride, potassium hydroxide, and potassium sulfate. Examples of raw material compounds containing Group 2 elements of the periodic table include magnesium compounds such as magnesium nitrate, magnesium sulfate, magnesium chloride, magnesium phosphate, and magnesium hydroxide, and calcium compounds such as calcium nitrate, calcium chloride, calcium hydroxide, calcium formate, calcium acetate, and calcium propionate. Examples of raw material compounds containing Group 13 elements of the periodic table include boric acid, metaborate, tetraborate, and borate. Specific examples of metaborate include sodium borate and potassium borate, and specific examples of tetraborate include sodium tetraborate and potassium tetraborate. Specific examples of borates include sodium pentaborate and potassium pentaborate. Examples of aluminum compounds include aluminum nitrate, aluminum sulfate, aluminum chloride, aluminum phosphate, aluminum hydroxide, aluminum acetate, and aluminum oxalate. Examples of alkoxides that can be used include silicate alkoxides such as tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), tetrapropyl orthosilicate (TPOS), and tetrabutoxysilane, and aluminum alkoxides such as aluminum methoxide, aluminum ethoxide, and aluminum isopropoxide.Furthermore, aluminosilicates such as sodium aluminosilicate, potassium aluminosilicate, and calcium aluminosilicate, solutions in which aluminum oxide is dispersed in a solvent, and sol solutions of aluminum oxide can also be used.

[0051] The total concentration of the raw material compounds in the raw material solution is usually from 0.01 mol / L to the saturated concentration, and preferably from 0.1 to 1.0 mol / L.

[0052] Next, in a heating furnace, the raw material solution is sprayed from the liquid outlet of the fluid nozzle of the present invention, and at the same time, gas is ejected from the gas outlet toward the raw material solution, and gas is blown from the gas outlet of the gas inlet tube toward the short side of the outlet. This prevents the mist from being entrained, makes it difficult for the mist to adhere to the periphery of the outlet, and suppresses the precipitation of solidified materials, making it possible to produce inorganic oxide particles (microparticles) having the desired particle size over a long period of time.

[0053] The flow rate of the raw material solution is usually 1 to 300 L / h, preferably 5 to 250 L / h, and more preferably 20 to 200 L / h. The ejection speed of the raw material solution is usually 1 to 50 m / s, preferably 3 to 35 m / s, and more preferably 5 to 20 m / s. The temperature inside the heating furnace can be appropriately selected depending on the type of raw material solution, but is usually 100 to 1800°C, preferably 150 to 1500°C, and more preferably 150 to 1300°C.

[0054] The inorganic oxide particles (microparticles) generated by drying or thermal decomposition can be transferred from the downstream of the heating furnace to a recovery device by an induction fan and recovered. Examples of the recovery device include a cyclone powder recovery machine and a bag filter. When recovering the microparticles, the particle size may be adjusted by passing them through a filter. Furthermore, a dust removal and purification device such as a scrubber may be disposed downstream of the recovery device as necessary.

[0055] Specific examples of inorganic compounds constituting the inorganic oxide particles include sodium oxide, potassium oxide, magnesium oxide, calcium oxide, barium oxide, zinc oxide, copper oxide, boron oxide, aluminum oxide, iron oxide, silicon oxide, aluminosilicate, aluminoborosilicate, and barium borosilicate. In addition, composite oxides combining inorganic oxides may be used.

[0056] The inorganic oxide particles (microparticles) produced by the spray drying apparatus or spray pyrolysis apparatus of the present invention may be solid particles, porous particles, hollow particles, or a mixture of two or more of these. Here, in this specification, "solid particles" refers to particles with a structure that does not have a cavity inside, and examples thereof include particles consisting of a single layer and particles having a core (also called an inner core) and a shell layer (also called an outer shell). Furthermore, "hollow particles" refers to particles with a structure having a cavity (hollow part) inside and having a cavity surrounded by an outer shell. The number of cavities may be single or multiple. Furthermore, "porous particles" refers to particles having a large number of through holes connected from the particle surface to the inside. The size and shape of the through holes are not particularly limited. Furthermore, the particles may have closed pores inside. EXAMPLES

[0057] Examples 1 to 6 A raw solution of 0.04 mol of aluminum nitrate and 0.16 mol of tetraethyl orthosilicate dissolved in 1 L of distilled water was placed in a solution tank. Next, the raw solution was pumped into a fluid nozzle, and the raw solution was sent from the fluid nozzle at a flow rate of 100 L / h, and the ejection speed of the raw solution was set to 5.6 m / s. The raw solution was sprayed in a mist state into a heating furnace at 1000°C, and at the same time, gas was sprayed from the gas outlet of the gas inlet tube toward the short side of the outlet under the conditions shown in Table 1 to produce inorganic oxide hollow particles, and the inorganic oxide hollow particles were collected using a bag filter. This operation was carried out for 8 hours.

[0058] Comparative Example 1 Inorganic oxide hollow particles were produced in the same manner as in Example 1, except that the gas inlet tube was not provided, and the inorganic oxide hollow particles were recovered using a bag filter. This operation was carried out for 8 hours.

[0059] 〔evaluation〕 For the collected inorganic oxide hollow particles, a particle size distribution was created based on the volumetric standard in accordance with JIS R 1629 using a particle size distribution analyzer (MT3000II, manufactured by Microtrack Bell), and the particle size corresponding to 50% of the cumulative distribution curve (D 50The particle diameter (average particle size) and the percentage of ultrafine particles of 10 μm or less were determined. In addition, the presence or absence of adhesion to the protrusion of the fluid nozzle was visually confirmed, and if adhesion occurred, the vertical length of the adhesion was measured with a ruler. The results are shown in Table 1.

[0060] [Table 1]

[0061] A comparison between Examples 1 to 6 and Comparative Example 1 shows that by providing a gas inlet pipe for blowing gas on the short side of the outlet of the fluid nozzle, mist is less likely to adhere to the periphery of the outlet, and therefore deposition of solidified matter can be suppressed. Also, a comparison between Examples 1 to 4 and Examples 5 to 6 shows that by providing a swirl mechanism at the gas outlet of the gas inlet pipe, the proportion of particles larger than 10 μm is suppressed to less than 10%, so not only can deposition of solidified matter be suppressed, but particle size can also be made substantially uniform. [Explanation of symbols]

[0062] 1 Liquid outlet 2 Gas outlet 3 Protrusion 4 Short side end of outlet 5. Packing 6. Centre Block 7 Side Block 8. Mist 9 Gas introduction tube 10 Gas outlet 11 Fluid nozzle 20 Fluid Nozzle 31 Heating furnace 32 Heating device 33 Insulation 100 Spray drying equipment or spray pyrolysis equipment

Claims

1. a fluid nozzle body having a discharge port having a horizontally elongated rectangular shape in plan view, the discharge port being composed of a liquid discharge port for discharging a liquid and a gas discharge port adjacent to both ends of the liquid discharge port; A gas introduction pipe that is provided along the height direction of the outer periphery of the fluid nozzle body and is bent toward the short side of the discharge port via a bent portion, and that blows gas from a gas discharge port at the tip toward the short side of the discharge port of the fluid nozzle. A fluid nozzle comprising:

2. 2. The fluid nozzle according to claim 1, wherein the gas outlet of the gas inlet pipe has a swirling mechanism for blowing a swirling air current toward a short side of the discharge port.

3. The fluid nozzle of claim 1 , wherein the turning mechanism is a plate unit.

4. 2. The fluid nozzle according to claim 1, wherein the gas introduction pipe is installed in any one of the following (1) to (3), or in a combination of two or more of these: (1) One or more sets of gas introduction pipes are installed symmetrically with respect to the center line in the longitudinal direction of the discharge port. (2) One or more sets of gas introduction pipes are installed symmetrically with respect to the center line in the short direction of the discharge port. (3) One or more pairs of gas introduction pipes are installed diagonally around the intersection of the center line of the discharge port in the longitudinal direction and the center line of the discharge port in the lateral direction.

5. 2. The fluid nozzle according to claim 1, wherein the gas introduction pipe is bent at an angle between 30 degrees upward and 60 degrees downward with respect to the horizontal direction via the bent portion so that the gas discharge port faces the short side of the discharge port.

6. A fluid nozzle that discharges a raw material solution; A heating furnace that dries or pyrolyzes the mist of raw material solution discharged from a fluid nozzle Equipped with The fluid nozzle is the fluid nozzle according to any one of claims 1 to 5. Spray drying equipment or spray pyrolysis equipment.

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