JP4516642B2 - Spray pyrolysis equipment - Google Patents

Description

【００２９】
【発明の効果】
以上説明したように、本発明の噴霧熱分解装置は、噴霧ノズルで噴霧された原液を、バーナーの火炎で直接、固化後熱分解することができ、噴霧された原液の熱分解効率を向上させるとともに、熱分解時間を大幅に短縮することができる。
【図面の簡単な説明】
【図１】 噴霧熱分解装置の一例の要部を示す説明図である。
【図２】 本発明の噴霧熱分解装置の一例の要部を示す説明図である。
【図３】 本発明の噴霧熱分解装置の一例を示す概略断面図である。
【図４】 本発明の噴霧熱分解装置の他の例を示す概略断面図である。
【図５】 従来の噴霧熱分解装置の一例を示す概略断面図である。
【符号の説明】
２…反応室、４…反応管、５…チャンバー、６…チャンバーと反応管との間隙部、８…冷却用ガス導入口、９…粉体取出し口、１０…噴霧ノズル、２０…バーナー、２２…燃料ガス流路、２４…燃焼空気流路、３０…冷却設備、４０…粉体分離捕集設備、５０…排気ファン、６０…電気炉。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spray pyrolysis apparatus, and more particularly, to a spray pyrolysis apparatus used for synthesizing a metal oxide or metal non-oxide powder having high purity, composition uniformity and fineness and high reaction activity. .
[0002]
[Prior art]
Finer properties of fine ceramics can only be obtained by controlling the purity, chemical composition and fine structure of the raw materials.
At this time, the manufacturing process, especially the raw material synthesis method, is often the key to product development.
The raw material powder is required to have high purity, a uniform composition in the case of a compound / mixture, and a fine and high reaction activity.
[0003]
Various synthetic methods for obtaining ceramic powders having such properties have been devised, but as a synthetic method for satisfying the requirements of fineness, high purity, and high composition uniformity, a gas phase or a liquid phase is used. There is a synthesis method.
Unlike the case of using a conventional solid phase, the synthesis method via a liquid phase is considered that each constituent element is mixed in atomic order.
The liquid phase method is a method in which a metal element present in a solvent is precipitated as hydroxide, nitrate, sulfate, carbonate, etc., and is thermally decomposed to synthesize oxide fine powder.
As the liquid phase method, many methods have been developed due to the difference in the metal salt precipitation method and the thermal decomposition method. In particular, the spray pyrolysis method has attracted attention.
[0004]
The spray pyrolysis method sprays a metal salt solution as fine droplets in an atmosphere maintained at a temperature higher than the temperature at which pyrolysis occurs, and evaporates the solvent, precipitates the metal salt, and pyrolyzes it in a very short time. This is a method of synthesizing fine oxide (or non-oxide) fine powder.
Powders obtained by this method have the advantages of compositional uniformity on the atomic scale and uniform dispersibility of trace component elements, and fine particles with good dispersibility can be obtained.
Even if there is a compositional non-uniformity due to drying or thermal decomposition, it is physically limited within the divided fine particles, so that there is little composition separation due to rearrangement of components.
Moreover, since the ratio of the component contained in each sprayed solution is very close to that of the adjusted solution, the dispersion of the component can be strictly controlled.
[0005]
In order to perform the spray pyrolysis method as described above, for example, a spray pyrolysis apparatus shown in FIG. 5 is currently used.
This type of apparatus uses the electric furnace 60 provided around the outside of the reaction chamber 2 to maintain the high temperature atmosphere of 500 to 1300 ° C. in the reaction chamber 2 and extremely reduces the stock solution sprayed by the spray nozzle 10. It is a product that synthesizes fine powder as a product by thermal decomposition after solidification in a short time.
[0006]
However, since the spray pyrolysis apparatus described above is indirect heating using the radiant heat of the side wall of the reaction chamber 2, the temperature of the high-temperature atmosphere in the reaction chamber 2 depends on the durability temperature of the material of the reaction chamber 2. In addition, there is a problem that running cost is increased due to poor thermal decomposition efficiency.
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of such problems of the prior art, and the stock solution sprayed by the spray nozzle can be directly pyrolyzed after solidification with a burner flame, and the sprayed stock solution An object of the present invention is to provide a spray pyrolysis apparatus capable of improving the thermal decomposition efficiency and greatly shortening the thermal decomposition time.
[0008]
[Means for Solving the Problems]
That is, according to the present invention, there is provided a spray pyrolysis apparatus for spraying a stock solution into a reaction chamber, solidifying the sprayed stock solution in a high-temperature atmosphere and then pyrolyzing, and taking out the obtained powder from the chamber , A spray nozzle provided at the center of the upper or lower part in the chamber , a burner provided around the spray nozzle, a reaction tube disposed so as to surround the burner and form the reaction chamber ; A spray pyrolysis apparatus comprising: a reaction tube cooling means for introducing a cooling gas into a gap between the chamber and the reaction tube and bringing the cooling gas into contact with the outer wall surface of the reaction tube and cooling the reaction tube. Provided.
[0010]
Moreover, in this invention, it is preferable that the spray nozzle is integrated with the burner.
[0011]
Furthermore, in the present invention, the spray nozzle is preferably a two-fluid spray nozzle or a pressure spray nozzle, and the burner is preferably a diffusion type burner.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The spray pyrolysis apparatus of the present invention is a spray pyrolysis apparatus that sprays a stock solution into a reaction chamber, solidifies the sprayed stock solution in a high-temperature atmosphere and then thermally decomposes, and takes out the obtained powder from the chamber . A spray nozzle provided at the center of the upper or lower part in the chamber , a burner provided around the spray nozzle, a reaction tube surrounding the burner and arranged to form a reaction chamber, and the chamber and the reaction A reaction tube cooling means is provided for introducing a cooling gas into a gap with the tube and bringing the cooling gas into contact with the outer wall surface of the reaction tube for cooling .
[0013]
As described above, the spray pyrolysis apparatus of the present invention can directly heat and solidify the stock solution sprayed by the spray nozzle with the flame of the burner and improve the thermal decomposition efficiency of the sprayed stock solution. The pyrolysis time can be greatly shortened.
[0015]
Hereinafter, the present invention will be described in more detail with reference to the drawings.
An example of the spray pyrolysis apparatus of the present invention includes, as shown in FIG. 2, at least one spray nozzle 10 provided at the center of the lower part in the reaction chamber 2, and a burner 20 provided around the spray nozzle 10. The reaction tube 4 disposed so as to surround the burner 20 and means for cooling the reaction tube are provided.
The reaction tube 4 used in the present invention also has a flame holding tube function for stably holding the flame of the burner.
[0016]
In the spray pyrolysis apparatus shown in FIG. 2 , since the stock solution sprayed from the center of the burner 20 is introduced into the flame of the burner 20, the spray pyrolysis apparatus was sprayed as compared with the conventional apparatus (see FIG. 5). The stock solution can be introduced into a higher temperature atmosphere (1500 ° C. or higher).
From the above, the spray pyrolysis apparatus shown in FIG. 2 can improve the thermal decomposition efficiency of the sprayed stock solution, can greatly shorten the thermal decomposition time, and can also downsize the apparatus.
[0017]
In addition, the apparatus shown in FIG. 2 is provided with means for cooling the reaction tube having a structure in which cooling gas is brought into contact with the outer wall surface of the reaction tube 4 to cool it.
Specifically, as shown in FIG. 2, a cooling gas is introduced into a gap 6 between the chamber and the reaction tube from a cooling gas introduction port 8 disposed in the lower portion of the side wall of the chamber 5.
Thereby, even if it is a case where a high temperature atmosphere (1500 degreeC or more) is hold | maintained in a reaction tube, since the reaction tube can fully be cooled, the lifetime of a reaction tube can be improved significantly.
[0018]
The cooling gas used in the present invention is preferably air, N ₂ gas, Ar gas or the like, although it varies depending on the stock solution to be sprayed.
Moreover, it is preferable that the temperature of the gas for cooling is 40-120 degreeC.
[0019]
Here, the spray nozzle 10 used in the present invention is a two-fluid spray nozzle (a nozzle that atomizes a liquid by a shear force of a high-speed superheated steam flow or a high-pressure air flow) or a pressure spray nozzle so as not to disturb the stable combustion of the burner. (A nozzle that pressurizes the liquid and ejects it from the jet outlet at high speed to atomize it).
As shown in FIG. 2 , the spray nozzle used in the present invention preferably has a structure integrated with the burner (the spray nozzle 10 is disposed at the center of the burner 20).
[0020]
The burner 20 used in the present invention is preferably a diffusion burner (gas combustion device) that can realize combustion under a wide range of combustion conditions because the stock solution is sprayed inside the flame of the burner. .
Here, as shown in FIG. 2, the diffusion type burner advances the combustion while diffusing and mixing the fuel gas and air supplied from the fuel gas passage 22 and the air passage 24 from the tip of the burner 20. is there.
In addition, in the diffusion type burner, it is necessary to realize good turbulent mixing of the fuel gas and air while maintaining the flame, so that the swirl flow burner that swirls the combustion air and blows it into the reaction tube It is preferable that
In addition, the burner used by this invention can make the temperature of a burner 1800 degreeC or more by using oxygen instead of air.
[0021]
Furthermore, the material of the reaction tube 4 used in the present invention is preferably ceramics such as alumina, mullite, quartz, etc. having high heat resistance because it is affected by the flame of the burner. Therefore, metals such as stainless steel, Hastelloy, and high Ni heat-resistant alloys may be used.
[0022]
Next, the spray pyrolysis apparatus of the present invention will be described in more detail based on FIGS.
The spray pyrolysis apparatus shown in FIG. 3 has a chamber 5 whose upper end is formed in a substantially cylindrical shape having a conical shape, a spray nozzle 10 provided in the center of the lower portion of the chamber 5, and a spray nozzle 10 that is provided around the spray pyrolyzer. The burner 20, the reaction tube 4 disposed so as to surround the burner 20, the cooling gas inlet 8 disposed in the lower portion of the side wall in the chamber 5, and the powder disposed in the upper portion of the chamber 5 A body outlet 9 is provided.
Here, the spray pyrolysis apparatus shown in FIG. 3 can reliably take out the powder without the powder remaining in the reaction chamber even when the obtained powder is light.
[0023]
In addition, the spray pyrolysis apparatus shown in FIG. 4 includes a chamber 5 having a substantially cylindrical shape whose lower end portion is an inverted conical shape, a spray nozzle 10 provided in the center of the upper portion of the chamber 5, and a spray nozzle 10. A peripheral burner 20, a reaction tube 4 disposed so as to surround the burner 20, a cooling gas inlet 8 disposed in a lower portion of the side wall in the chamber 5, and a lower portion of the chamber 5. The powder take-out port 9 is provided.
Here, since the spray pyrolysis apparatus shown in FIG. 4 can sufficiently expect natural sedimentation due to gravity when the obtained powder is heavy, the powder can be reliably taken out.
[0024]
The cooling gas introduced from the cooling gas inlet 8 into the gap 6 between the chamber and the reaction tube cools the outer wall surface of the reaction tube 4 and is then exhausted from the powder outlet 8 as exhaust gas.
The powder outlet 9 is connected to an exhaust fan 50 through a cooling facility 30 such as a heat exchanger and a cooling tower, and a powder separation and collection facility 40 such as a cyclone, a bag filter, and an electric dust collector. .
[0025]
The stock solution sprayed from the spray nozzle 10 comes into contact with the flame of the burner 20 to be pyrolyzed after being solidified and pulverized.
The obtained powder is accompanied by the exhaust gas and is taken out from the powder take-out port 9 as an exhaust gas containing powder.
The exhaust gas containing the powder is cooled to a predetermined temperature by the cooling facility 30 and then separated from the exhaust gas and the powder by the powder separation / collection facility 40 to obtain a powder as a product. .
In addition, the exhaust gas separated by the powder separation and collection facility 40 is subjected to a removal process of environmental pollutants (NO _{X and the} like) by an exhaust gas treatment facility (not shown).
[0026]
The embodiments of the present invention have been described above. However, the present invention should not be construed as being limited to these embodiments, and the knowledge of those skilled in the art can be obtained without departing from the scope of the present invention. Various changes, modifications, improvements and the like can be added based on this.
[0027]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not restrict | limited to these Examples.
(Examples 1-4)
Spray pyrolysis was performed using the spray pyrolysis apparatus shown in FIG. 3 under the experimental conditions shown in Table 1 (Examples 1 to 4).
As shown in Table 1, it has been found that the spray pyrolysis apparatus of the present invention can be suitably applied to the synthesis of fine particles such as battery materials, ferrite materials, and catalysts.
[0028]
[Table 1]

[0029]
【The invention's effect】
As explained above, the spray pyrolysis apparatus of the present invention can directly heat and solidify the stock solution sprayed by the spray nozzle with the flame of the burner, and improve the thermal decomposition efficiency of the sprayed stock solution. At the same time, the thermal decomposition time can be greatly shortened.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a main part of an example of mists pyrolysis apparatus.
FIG. 2 is an explanatory view showing a main part of an example of a spray pyrolysis apparatus of the present invention.
FIG. 3 is a schematic sectional view showing an example of a spray pyrolysis apparatus of the present invention.
FIG. 4 is a schematic sectional view showing another example of the spray pyrolysis apparatus of the present invention.
FIG. 5 is a schematic sectional view showing an example of a conventional spray pyrolysis apparatus.
[Explanation of symbols]
2 ... reaction chamber, 4 ... reaction tube, 5 ... chamber, 6 ... gap between chamber and reaction tube, 8 ... cooling gas inlet, 9 ... powder outlet, 10 ... spray nozzle, 20 ... burner, 22 DESCRIPTION OF SYMBOLS ... Fuel gas flow path, 24 ... Combustion air flow path, 30 ... Cooling equipment, 40 ... Powder separation collection equipment, 50 ... Exhaust fan, 60 ... Electric furnace.

Claims (4)

A spray pyrolysis apparatus for spraying the stock solution into the reaction chamber, solidifying the sprayed stock solution in a high-temperature atmosphere and then thermally decomposing the resulting powder from the chamber ,
A spray nozzle provided in the upper or lower center of the chamber ;
A burner provided around the spray nozzle;
A reaction tube surrounding the burner and arranged to form the reaction chamber ;
A reaction tube cooling means for introducing a cooling gas into a gap between the chamber and the reaction tube and bringing the cooling gas into contact with the outer wall surface of the reaction tube to cool the reaction tube ;
A spray pyrolysis apparatus comprising:   The spray pyrolysis apparatus according to claim 1, wherein the spray nozzle is integrated with a burner. The spray pyrolysis apparatus according to claim 1 or 2, wherein the spray nozzle is a two-fluid spray nozzle or a pressure spray nozzle. The spray pyrolysis apparatus according to any one of claims 1 to 3, wherein the burner is a diffusion type burner.

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