JP6854541B1 - Spray thermal decomposition device and spray thermal decomposition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spray thermal decomposition apparatus capable of mass-producing the fine particles while maintaining a constant quality of the fine particles which are products by thermally decomposing the raw material droplets. SOLUTION: A reaction furnace 11 for heating and decomposing raw material droplets, a plurality of sprayers 13 arranged above the reaction furnace 11 and spraying the raw material droplets into the reaction furnace 11, and an outer peripheral portion of the reaction furnace 11. The reactor 11 has a ceramic side wall portion 14 having a rectangular tubular shape and the side wall portion 14 is a heating portion 15. The temperature inside the reactor 11 rises as a result of being heated by, and the plurality of atomizers 13 are arranged in a row along the extending direction of the long side of the side wall portion 14 of the reactor 11. 100. [Selection diagram] Fig. 1

Description

The present invention relates to a spray pyrolysis apparatus and a spray pyrolysis method. More specifically, the present invention relates to a spray pyrolysis apparatus and a spray pyrolysis method capable of mass-producing fine particles as products.

Conventionally, in the field of handling various materials such as battery materials, magnetic materials, various catalysts, superconducting materials, and ceramics, it has been attempted to obtain high-performance fine particles by liquid phase synthesis, and high-performance fine particles have been obtained. A small spray pyrolysis device, a spray pyrolysis device using a combustion gas, and the like are known.

Specifically, as a small spray pyrolysis apparatus, there is known an apparatus in which a raw material solution is introduced and sprayed into a reaction chamber at a predetermined temperature and pyrolyzed to produce ceramic powder (see Patent Document 1). The spray thermal decomposition apparatus of Patent Document 1 includes a sprayer, a reaction chamber, and a heating means surrounding the reaction chamber, and the heating means includes a plurality of heaters provided with a temperature measuring means. ..

Further, as a spray pyrolysis device using combustion gas, a sprayer that sprays raw material droplets, a cylindrical reactor that heats and decomposes the raw material droplets sprayed from the sprayer in a high temperature atmosphere, and hot air are passed through. It is known that a ventilation section and a circulation fan for reheating the hot air discharged from the ventilation section are provided (see Patent Document 2).

Japanese Unexamined Patent Publication No. 05-253469 Japanese Unexamined Patent Publication No. 2014-121704

However, in Patent Document 1, there is a limit to the amount of raw material droplets capable of reaction treatment per unit, and there is no problem in relatively small-scale production, but it is said that mass production of fine particles as products is efficiently performed. There was still room for improvement in terms of points.

In Patent Document 2, when the reaction is carried out with a gas having a high temperature of 800 ° C. or higher in the reaction furnace, it may be difficult to operate for a long time. Specifically, the spray pyrolysis apparatus of Patent Document 2 circulates a high-temperature gas, but in order to carry out a high-temperature reaction of 800 ° C. or higher in the reactor, the temperature is 800 ° C. or higher in the reactor. It is necessary to supply a high temperature gas (for example, a gas having a temperature of 1000 ° C. or higher). However, in this case, the circulation fan for circulating the gas cannot withstand the high temperature gas, and it may be difficult to use it for a long period of time.

For these reasons, the quality of the obtained product (fine particles) is constant, the amount of raw material droplets processed per unit time is large, and the development of a spray pyrolysis apparatus capable of mass-producing products has been eagerly desired.

The present invention has been made to solve the above-mentioned problems of the prior art, the quality of the obtained product (fine particles) is constant, the amount of raw material droplets processed per unit time is large, and the product The present invention provides a spray pyrolysis apparatus and a spray pyrolysis method capable of mass production.

The present invention provides the following spray pyrolysis apparatus and spray pyrolysis method.

[1] A reactor that heats and decomposes raw material droplets,
A plurality of atomizers arranged above the reactor and spraying the raw material droplets into the reactor.
A heating unit, which is arranged on the outer peripheral portion of the reactor and heats the reactor, is provided.
The reactor has a ceramic side wall portion having a rectangular tubular cross section, and the side wall portion is heated by the heating portion to raise the temperature inside the reaction furnace.
A spray thermal decomposition apparatus in which the plurality of atomizers are arranged in a row along the extending direction of a long side in the side wall portion of the reactor.

[2] The spray pyrolysis apparatus according to the above [1], wherein the side wall portion of the reaction furnace is made of mullite, alumina, quartz glass, silicon carbide, or silicon nitride.

[3] The spray pyrolysis apparatus according to the above [1] or [2], wherein all the sprayers are located in the central portion between a pair of long sides of the side wall portion in the reaction furnace.

[4] The spray pyrolysis apparatus according to any one of [1] to [3], wherein the distance between adjacent sprayers is 50 to 500 mm.

[5] Any of the above [1] to [4], each of the atomizers is connected to a branch path branched from one supply path connected to the raw material storage tank for storing the raw material droplets. The spray pyrolysis apparatus described in Crab.

[ 6 ] The spray pyrolysis apparatus according to any one of [1] to [5] above, wherein the reaction furnace has an internal temperature of 500 to 1500 ° C.

[ 7 ] A method for spraying thermal decomposition of raw material droplets, wherein the raw material droplets are heated and decomposed using the spray thermal decomposition apparatus according to any one of [1] to [ 6] to produce fine particles.
The raw material droplets having an average particle size of 0.1 to 10 μm are sprayed into the reaction furnace.
The raw material droplets are heated and decomposed at 500 to 1500 ° C. in the reaction furnace.
A spray pyrolysis method in which the processing amount of the raw material droplets is 4 to 30 L / hour.

[ 8 ] The spray thermal decomposition method according to [7 ], wherein the distance between adjacent sprayers is 50 to 500 mm, and the spray angle of the raw material droplets in the sprayer is 20 to 90 °.

The spray pyrolysis apparatus of the present invention has the effect of being able to mass-produce the fine particles while maintaining the quality of the fine particles as a product by heating and decomposing the raw material droplets.

According to the spray thermal decomposition method of the present invention, it is possible to heat-decompose the raw material droplets to maintain the quality of the fine particles as a product at a constant level, and it is possible to mass-produce the fine particles.

It is explanatory drawing which shows typically one Embodiment of the spray thermal decomposition apparatus of this invention. It is explanatory drawing schematically as seen from above the reactor of the spray pyrolysis apparatus of this invention. It is explanatory drawing which looked at the reactor of the spray pyrolysis apparatus schematically from above.

Hereinafter, embodiments for carrying out the present invention will be described, but the present invention is not limited to the following embodiments. That is, it is understood that, as long as the gist of the present invention is not deviated, those which have been appropriately modified, improved, etc. to the following embodiments based on the ordinary knowledge of those skilled in the art also belong to the scope of the present invention. Should be.

(1) Spray pyrolysis device:
One embodiment of the spray pyrolysis apparatus of the present invention is the spray pyrolysis apparatus 100 shown in FIG. The spray thermal decomposition apparatus 100 includes a reaction furnace 11 that heats and decomposes the raw material droplets 10, a plurality of sprayers 13 that are arranged above the reaction furnace 11 and spray the raw material droplets 10 into the reaction furnace 11. It is arranged on the outer peripheral portion of the reaction furnace 11 and includes a heating unit 15 for heating the reaction furnace 11. The reaction furnace 11 has a side wall portion 14 made of ceramics having a rectangular tubular shape in cross section, and the side wall portion 14 is heated by the heating portion 15 to raise the temperature inside the reaction furnace 11. The plurality of atomizers 13 are arranged in a row along the extending direction of the long side of the side wall portion 14 of the reactor 11.

The spray pyrolysis apparatus 100 can mass-produce the fine particles while maintaining the quality of the fine particles as a product by heating and decomposing the raw material droplets 10 (for example, the average particle size can be reduced). Is. Conventionally, there is a request for producing fine particles (products) having a small average particle size, and further there is a request for mass production of the fine particles. However, in order to mass-produce the fine particles, it is necessary to increase the liquid amount of the raw material, but in order to increase the liquid amount of the raw material, it is necessary to increase the opening diameter of the nozzle of the sprayer. On the other hand, if the opening diameter of the nozzle of the atomizer is increased, the particle size of the raw material droplets becomes large, and it becomes difficult to obtain fine particles having a small average particle size. As described above, the production of fine particles having a small average particle diameter and the mass production of the fine particles are incompatible with each other. Despite this relationship, according to the spray pyrolysis apparatus of the present invention, as described above, fine particles having a small average particle size can be mass-produced.

Further, in the conventionally known spray pyrolysis apparatus, one sprayer is usually provided in one reaction furnace, and when trying to mass-produce fine particles (products), the production capacity is not sufficient. It was. Therefore, two conventionally known spray thermal decomposition devices may be prepared to produce fine particles. However, if two spray pyrolysis devices are adopted, there is a problem that the installation space is required. In particular, when used in a semi-clean room, the installation space is limited, and it may not be possible to install a plurality of spray pyrolyzers. Further, when a plurality of spray pyrolysis devices are used, the fine particles obtained by each spray pyrolysis device react in order to prevent a slight difference in the average particle size and the like, or to prevent such a slight difference. Highly accurate operations such as adjusting the time and making the inside of the reactor the same atmosphere are required. Although it is possible to prevent the installation space from being widened by arranging the two spray pyrolyzers one above the other, there is a problem that the height becomes too high and the quasi-clean room cannot be entered.

On the other hand, when the spray pyrolysis apparatus of the present invention is used, the installation space is not widened because two spray pyrolysis apparatus are not adopted, and the height thereof is the same as that of the conventionally known spray pyrolysis apparatus. It is in a semi-clean room. Further, reaction gases, carrier gases, etc., for example, N ₂ , Ar, He, Ne, CO ₂ , O ₂ , which are the same as those that can be used in the conventional spray pyrolysis apparatus, can be used.

The spray pyrolysis device 100 is a so-called indirect heating type spray pyrolysis device having a heating unit 15 on the outer periphery of the reaction furnace 11. Unlike the direct heating type, such an indirect heating type spray pyrolysis apparatus can adjust the composition of the gas in the reaction furnace. On the other hand, the indirect heating type spray thermal decomposition device has a lower temperature in the reaction furnace than the direct heating type spray thermal decomposition device, but the spray thermal decomposition device of the present invention has a side wall portion 14 made of ceramics. The reactor 11 is provided, and the temperature inside the reactor 11 is prevented from becoming low.

The spray pyrolysis apparatus of the present invention can also be used as a spray dryer (spray dryer). When used as a spray dryer, it can also be used as a device for scaling up a device (small tester) equipped with one sprayer in one reactor, which is the same as that obtained with a small tester. A particle size distribution can be achieved.

The average particle size of the fine particles obtained by heating and decomposing in the reaction furnace 11 can be 0.01 to 10 μm.

As the fine particles is not particularly limited, for _{example, BaTiO 3, Li 3 PO 4} , LiCoO 2, La x Ce 1 -xO 2, Y 2 O 3 -ZrO 2, NiCo 2 O 4, SrPd 3 O 4, Multi-component oxides such as (Sr _x Ba _1-x ) TiO ₃ , La _0.8 Sr _0.2 Ni _0.5 Co _0.5 O _{3-x , ZrO 2} , Y ₂ O ₃ , MgO, CeO ₂ , CaO, Al ₂ O ₃ , SiO ₂ , TiO ₂ , Fe ₂ O ₃ , FeO, NiO, CoO, CuO, ZnO, MnO, PbO, BaO, SrO, Mn ₂ O ₃ , Cr ₂ O ₃ , La ₂ O _{3, Pr 2 O 3, in} 2 O 3, SnO 2, WO 3, one component oxides such as _{NdO 3, ZnS, CdS, (} Zn x Cd 1-x) sulfides such as S, such as beta-SiC Examples include silicates, metals such as Ni, Ag and Pd, alloys such as Ag-Pd and Ni-Fe, and composites such as _{(La, Sr) MnO 3-} YSZ, Pd-Ca and Pd-SiO _2. it can.

(1-1) Reactor:
The reaction furnace 11 heats and decomposes the raw material droplets 10. The reactor 11 has a ceramic side wall portion 14 having a rectangular tubular cross section, and the side wall portion 14 is heated by the heating portion 15 to raise the temperature inside the reactor 11. When the temperature inside the reaction furnace 11 rises to a predetermined temperature, the raw material droplets are heated and decomposed.

The material constituting the side wall portion 14 of the reaction furnace 11 is ceramics as described above, and specific examples of such ceramics include mullite, alumina, quartz glass, silicon carbide, silicon nitride and the like. .. Among these, if mullite is adopted, the temperature inside the reactor 11 can be made higher.

The side wall portion 14 of the reactor 11 has a rectangular tubular shape having a rectangular cross section (that is, a cross section orthogonal to the central axis direction). Here, in the conventional spray pyrolysis apparatus, the shape of the reactor is usually cylindrical, and the side wall portion 14 of the reactor 11 is originally made into a square cylinder as in the present invention. is not it. This is because when the corners are formed like a square cylinder, fine particles are likely to accumulate in the corners and it may take time and effort for cleaning. However, on the other hand, the cylindrical reactor 111 as shown in FIG. 3 has a cylindrical wall portion 114, and when a plurality of atomizers 13 (five in FIG. 3) are arranged therein, the reactor A temperature difference is likely to occur between the central portion of 111 and the other portion, and there is a possibility that the raw material droplets cannot be heated uniformly. Further, since the temperature of the central portion of the reactor 111 is lower than the temperature of the surroundings thereof, when trying to raise the temperature of the central portion to a predetermined temperature, the temperature of the heating portion is higher than that of the square cylinder shape. The temperature needs to be set high. Further, if the distances K of the adjacent atomizers 13 are brought close to each other in order to eliminate the occurrence of such a temperature difference, the sprayed raw material droplets collide with each other before they are sufficiently dried, and the particle size of the obtained fine particles is obtained. May vary. The square tubular side wall portion 14 as in the present invention has an advantage that such a problem does not occur.

The dimensions of the reactor 11 are not particularly limited as long as the plurality of atomizers 13 can be arranged in a row along the extending direction of the long side of the side wall portion 14 of the reactor 11. For example, the "side wall on the long side" can be 400 to 2000 mm in width (long side), 1000 to 1500 mm in length (height), and 3 to 20 mm in thickness. Can have a width (short side) of 100 to 300 mm, a length (height) of 1000 to 1500 mm, and a thickness of 3 to 20 mm.

The temperature inside the reactor 11 is preferably 500 to 1500 ° C, more preferably 600 to 1300 ° C, and even more preferably 800 to 1200 ° C.

A plurality of openings 31 for collecting fine particles are formed below the reaction furnace 11. The number of the openings 31 may be one.

A recovery pipe 33 for recovering the obtained fine particles is connected to the opening 31 of the reaction furnace 11. In the spray thermal decomposition apparatus 100 shown in FIG. 1, the fine particle recovery pipe 33 is provided, but a recovery tank for recovering the fine particles may be provided instead of the recovery pipe 33.

The average particle size of the raw material droplets 10 can be appropriately set depending on the average particle size of the fine particles of the product, and can be, for example, 0.1 to 10 μm.

(1-2) Atomizer:
The atomizer 13 sprays the raw material droplets 10 into the reaction furnace 11. As such a sprayer 13, a sprayer used in a conventionally known spray thermal decomposition device can be appropriately adopted.

In the present invention, a plurality of atomizers 13 are provided above the reactor 11. The number is not particularly limited, but can be, for example, 2 to 20, and more preferably 5 to 10. The raw material droplet 10 sprayed from the atomizer 13 falls from above to below the reactor 11 due to its own weight, and is heated and decomposed during that time. The raw material droplet 10 may simply fall due to its own weight, or may be subjected to a downward force of the reactor 11 by the carrier gas.

The plurality of atomizers 13 are arranged in a row along the extending direction of the long side of the side wall portion 14 of the reactor 11, and by arranging in this manner, the raw material droplets sprayed from the atomizer 13 are arranged in the reactor. It will be heated evenly and uniformly in 11 and decomposed. Here, for example, when a plurality of atomizers 13 are arranged along the ring shape, the sprayed raw material droplets may collide with each other before they are dried, and those having a large particle size may be produced. As a result, the particle distribution of the obtained fine particles may vary.

The same atomizer 13 may be used, but different atomizers 13 may be used. Examples of the different atomizers 13 include those having different opening diameters of the nozzles 40 of the atomizers 13. The opening diameter of the nozzle 40 is one of the factors that determine the particle size of the raw material droplet 10, and if the opening diameter is small, the raw material droplet 10 having a small particle size can be obtained. On the other hand, if the opening diameter of the nozzle 40 is reduced, the productivity of the fine particles is lowered, and it is difficult to mass-produce the fine particles. In such a situation, by adopting the configuration as in the present invention, it is possible to mass-produce fine particles having a small particle size.

"Arranged in a row along the extending direction of the long side of the side wall portion 14 of the reactor 11" means the following state. That is, if the square tubular side wall portion 14 of the reactor 11 is partitioned by a partition plate parallel to the side wall portion 14 on the short side, one atomizer 13 (of the atomizer 13) is provided for each of the partitioned spaces. The state in which the nozzle 14) is arranged.

The distance D between the adjacent atomizers 13 (that is, the distance between the central axes of the nozzles 40 of the adjacent atomizers 13) can be 50 to 500 mm, and preferably 50 to 300 mm.

Each of the atomizers 13 may be connected to a branch path branched from one supply path connected to the raw material storage tank for storing the raw material droplet 10. By doing so, the raw materials under the same compounding conditions can be subjected to spray pyrolysis treatment, and a product (fine particles) having less variation in particle distribution can be obtained. As the raw material storage tank, the same one as that used in the conventionally known spray thermal decomposition apparatus can be appropriately adopted.

All nebulizers 13 (specifically, the central axis of the nozzle 40 of the nebulizer 13) are located in the central portion between a pair of long side portions (long side walls) of the side wall portions 14 in the reactor 11. As a specific length, the central axis of the nozzle 40 of all the atomizers 13 has a distance (shorter distance) L1 from the long side of the side wall portion 14, for example, 30 to 150 mm. Often in the range of 100-150 mm. By doing so, the raw material droplets sprayed on the central portion of the reactor 11 can be more reliably heated and decomposed. The "central portion between the pair of long side portions (long side walls) of the side wall portion 14" is an area in the range of 25 to 75% when the distance between the pair of long side walls is 100%. It shall be said.

Distance L2 between the short side portion (wall) of the side wall portion 14 in the reaction furnace 11 and the central axis of the nozzle 40 of the atomizer 13 (the end atomizer 13a which is the closest atomizer 13 to the wall on the short side side). L2 can be independently set to, for example, 50 to 300 mm, and preferably 100 to 150 mm. By setting the distances L2 and L2 as such, the raw material droplets sprayed from the end atomizer 13a can be more reliably heated and decomposed. The distances L2 and L2 are often the same as each other, and further, the distance between the long side wall and the central axis of the nozzle 40 (the shorter distance) is also good. The distances L1 and L1 between the long side wall and the central axis of the nozzle 40 are preferably the same.

(1-3) Heating part:
The heating unit 15 is arranged on the outer peripheral portion of the reaction furnace 11 and heats the reaction furnace 11. It is preferable that the temperature inside the reactor 11 can be set to 500 to 1500 ° C.

There is no particular limitation on such a heating unit 15. Specific examples thereof include an electric heater and a molybdenum disilicate heater (specifically, a cantal super heater) that can utilize radiant heat. The heating unit 15 may use a high-temperature gas, but when a high-temperature gas is used, a device provided with a circulation fan for circulating this gas is required. This circulation fan may be damaged if exposed to high temperatures for an extended period of time. Therefore, it is preferable to use the above-mentioned electric heater or molybdenum disilicate heater as the heating unit 15.

The position where the heating portion 15 is arranged may be the whole so as to cover the outer peripheral portion of the reactor 11, or may be a part of the outer peripheral portion.

(1-4) Other devices:
The spray pyrolysis apparatus of the present invention may further include a bag filter 21, a scrubber 23, and the like, as in the spray pyrolysis apparatus 100 shown in FIG. In addition to these, other devices used in the conventional spray pyrolysis device can be appropriately adopted.

(1-4-1) Bag filter:
The bag filter 21 is connected to the recovery pipe 33 of the reaction furnace 11, and the fine particles obtained in the reaction furnace 11 flow into the bag filter 21. As the bag filter 21, a bag filter or the like used in a conventionally known spray thermal decomposition apparatus can be appropriately adopted.

The number of bag filters 21 is not particularly limited, and may be one or a plurality of bag filters 21 may be connected.

(1-4-2) Scrubber:
The scrubber 23 is connected to the bag filter 21 and cleans the exhaust gas and the like discharged from the bag filter 21 so that the scrubber 23 can be disposed of. As the scrubber 23, a scrubber or the like used in a conventionally known spray thermal decomposition apparatus can be appropriately adopted.

(2) How to use the spray pyrolysis device (spray pyrolysis method):
The spray pyrolysis method of the present invention heats and decomposes raw material droplets using the spray pyrolysis apparatus of the present invention to produce fine particles, and is shown in the spray pyrolysis apparatus of the present invention (for example, FIG. 1). This is a method using a spray pyrolysis apparatus 100). In one embodiment of the spray pyrolysis method of the present invention, a raw material droplet 10 having an average particle diameter of 0.1 to 10 μm is sprayed into the reaction furnace 11 of the spray thermal decomposition device 100, and the raw material droplet 10 is reacted. In the furnace 11, it is heated to 500 to 1500 ° C. and decomposed. Then, in the spray pyrolysis method of the present invention, the processing amount of the raw material droplet 10 is set to 4 to 30 L / hour.

The average particle size of the raw material droplet 10 is 0.1 to 10 μm as described above, but it is preferably 0.1 to 5 μm. By setting such an average particle size, fine particles (products) having a small average particle size can be obtained.

The temperature in the reaction furnace 11 (that is, the heating and decomposition temperature of the raw material droplets) can be 500 to 1500 ° C, preferably 600 to 1300 ° C, and more preferably 800 to 1200 ° C. .. By setting the temperature in the reaction furnace 11 within the above range, good fine particles (products) can be obtained. If this temperature is too low, the raw material droplets tend to be unable to be sufficiently heated and decomposed.

The processing amount of the raw material droplet 10 can be 4 to 30 L / hour, preferably 10 to 20 L / hour. By setting the processing amount within the above range, there is a tendency that the raw material droplets cannot be sufficiently heated and decomposed.

In the spray pyrolysis method of the present invention, the distance between the adjacent atomizers 13 (that is, the distance between the central axes of the nozzles 40 of the adjacent atomizers 13) is set to 50 to 500 mm, and at that time, the raw material droplet 10 in the atomizer 13 is set. The spray angle of is preferably 20 to 90 °. This injection angle can be preferably 40 to 60 °. By setting the spray angle of the raw material droplets 10 within the above range, it is possible to prevent the raw material droplets 10 sprayed from the adjacent sprayers 13 from colliding with each other before they are sufficiently dried, and the particle size is more uniform. Fine particles can be obtained.

In the spray thermal decomposition method of the present embodiment, the raw material stored in the raw material storage tank is sprayed from a plurality of sprayers 13 into the reaction furnace 11 to form raw material droplets 10. Then, the sprayed raw material droplets 10 are heated and decomposed in the reaction furnace 11 to become fine particles. The fine particles are discharged to the outside of the reactor 11 through an opening 31 arranged below the reactor 11. After that, the fine particles flow into the recovery pipe 33 and are supplied into the bag filter 21 while being cooled by the cooling gas flowing in the recovery pipe 33. As for the fine particles supplied into the bag filter 21, necessary fine particles are collected by the bag filter 21 and separated from other components. The other separated components will be washed and processed by the scrubber 23.

Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples.

(Example 1)
A spray thermal decomposition device 100 as shown in FIG. 1 was manufactured. In this spray pyrolysis apparatus 100, the shape of the side wall portion of the thermal decomposition furnace (reaction furnace) is a rectangular parallelepiped (length 200 mm, width 1000 mm, height 1000 mm), and a mullite plate is adopted as the side wall portion. This mullite plate uses a side wall of 1000 mm in width, 1000 mm in length (height), and 10 mm in thickness as a side wall on the long side, and 200 mm in width, 1000 mm in length (height), and 10 mm in thickness as a side wall on the short side. Was used. Further, this spray pyrolysis apparatus is provided with five sprayers (that is, the number of spray nozzles is five) arranged in a row along the long side direction of the side wall portion, and the distance between adjacent sprayers is 200 mm. The distance between the side wall on the long side and the sprayer was 100 mm, and the distance between the side wall on the short side and the sprayer was 100 mm.

The average particle size of the raw material droplets was 1.0 μm. The processing amount of the raw material droplets was 10 L / hour. The temperature of the heating part (the temperature of the heater (specifically, the cantal super heater)) was 950 ° C., and the temperature inside the reactor was 900 ° C. at the center temperature before the start of spraying (at the time of spraying). The core temperature was 860-870 ° C.). The spray angle of the raw material droplets was 45 °. As the raw material, the one prepared as follows was used. First, a Ba solution in which Ba (NO ₃ ) ₂ is dissolved in distilled water and a Ti solution in which Ti [(CH ₃ ) ₂ CHO] ₄ is dissolved in 4N-HNO ₃ are prepared, and these are mixed and mixed. A solution was obtained. Then, distilled water was added to obtain a predetermined amount, which was used as a raw material.

The obtained fine particles were BaTiO ₃ fine particles, and the average particle size (average particle size of the primary particles of the powder) was 0.01 μm (the aggregated particle size of the powder was 3 μm). The synthesis rate of the product was 99.9%. The height of the spray pyrolysis apparatus 100 was 2.5 m.

In this example, as compared with Reference Example 1, the amount of the raw material supply liquid could be increased while maintaining the state of the obtained fine particles and the synthesis rate thereof. That is, the fine particles could be mass-produced without deteriorating the quality of the obtained fine particles. As a result, the pass / fail judgment was "passed". The results are shown in Table 1.

(Example 2, Comparative Example 1, Reference Example 1)
Except for the conditions shown in Table 1, the raw material droplets were heated and decomposed in the same manner as in Example 1. The results are shown in Table 1. In addition, Reference Example 1 shows an example using a conventional spray thermal decomposition apparatus.

In Example 2, the number of sprayers was increased (the number of spray nozzles was 10), and the raw material droplets were heated and decomposed. As a result, the processing amount of the raw material droplets becomes 20 L / hour, and it can be seen that further mass production is possible. On the other hand, in Comparative Example 1, a cylindrical reactor was adopted, and each atomizer was arranged as shown in FIG. In Comparative Example 1, the particle size of the obtained fine particles was larger than that of Examples 1 and 2 and Reference Example 1, and there were variations, and the temperature of the heating portion also needed to be higher. .. Further, the synthesis rate of the product was 67.6%, and sufficient results could not be obtained. Therefore, the pass / fail judgment was "failed".

As can be seen from the above, the spray pyrolysis apparatus of the present invention has a constant quality of the obtained product (fine particles) and a large amount of raw material droplets processed per unit time as compared with the conventional spray pyrolysis apparatus. , It turned out that the product can be mass-produced.

The spray pyrolysis apparatus of the present invention can be used as an apparatus capable of obtaining fine particles having a small average particle size in the production of fine particles such as _{BaTIO 3 and further enabling mass production thereof.}

10: Raw material droplets, 11,111: Reactor, 13: Atomizer, 13a: End atomizer, 14: Side wall, 15: Heating part, 21: Bag filter, 23: Scrubber, 31: Opening, 33: Recovery Piping, 40: Nozzle, 100: Spray pyrolyzer, 114: Wall, L1, L2: Distance.

Claims (8)

A reactor that heats and decomposes raw material droplets,
A plurality of atomizers arranged above the reactor and spraying the raw material droplets into the reactor.
A heating unit, which is arranged on the outer peripheral portion of the reactor and heats the reactor, is provided.
The reactor has a ceramic side wall portion having a rectangular tubular cross section, and the side wall portion is heated by the heating portion to raise the temperature inside the reaction furnace.
A spray thermal decomposition apparatus in which the plurality of atomizers are arranged in a row along the extending direction of a long side in the side wall portion of the reactor. The spray pyrolysis apparatus according to claim 1, wherein the side wall portion of the reactor is made of mullite, alumina, quartz glass, silicon carbide, or silicon nitride. The spray pyrolysis apparatus according to claim 1 or 2, wherein all the sprayers are located in the central portion between a pair of long sides of the side wall portion in the reaction furnace. The spray pyrolysis apparatus according to any one of claims 1 to 3, wherein the distance between the adjacent sprayers is 50 to 500 mm. The invention according to any one of claims 1 to 4, wherein a branch path branched from one supply path connected to a raw material storage tank for storing the raw material droplets is connected to each of the sprayers. Spray pyrolysis device. The spray pyrolysis apparatus according to any one of claims 1 to 5 , wherein the temperature inside the reactor is 500 to 1500 ° C. A method for spraying thermal decomposition of raw material droplets, wherein the raw material droplets are heated and decomposed using the spray thermal decomposition apparatus according to any one of claims 1 to 6 to produce fine particles.
The raw material droplets having an average particle size of 0.1 to 10 μm are sprayed into the reaction furnace.
The raw material droplets are heated and decomposed at 500 to 1500 ° C. in the reaction furnace.
A spray pyrolysis method in which the processing amount of the raw material droplets is 4 to 30 L / hour. The spray thermal decomposition method according to claim 7 , wherein the distance between the adjacent sprayers is 50 to 500 mm, and the spray angle of the raw material droplets in the sprayer is 20 to 90 °.

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