JP2022127997A - Atomization pyrolysis plant - Google Patents

Abstract

To provide an atomization pyrolysis plant capable of manufacturing hollow particles low in particle density and high in strength.SOLUTION: An atomization pyrolysis apparatus 100 includes a furnace body 1 made of a vertical tube, at least one combustion tube 2 connected to an outer peripheral surface of the furnace body 1, a combustion burner 3 placed at an edge section on a side opposite from the furnace body 1 of the combustion tube 2 and generating a flame to the furnace body 1, and an atomization nozzle 4 placed on a tube axis 1c of a bottom section of the furnace body 1 and spraying upward a water solution, in which the combustion tube 2 is placed such that a discharging direction 20 of the combustion gas from the combustion tube 2 does not intersect with the tube axis 1c of the furnace body 1, the combustion tube 2 has a contraction 21 at a connection section with the furnace body 1, when seeing from a direction vertical to the discharging direction 20 and a horizontal direction, an intersection B of the discharge direction 20 and the tube 1c of the furnace body 1 is positioned relative to a tip end A of the atomization nozzle 4, with 1/2 times lower than the inner diameter d1 of the furnace body 1 as a lower limit, and with three times higher than the inner diameter d1 of the furnace body 1 as an upper limit.SELECTED DRAWING: Figure 5

Description

The present invention relates to a spray pyrolysis apparatus.

A manufacturing apparatus utilizing a spray pyrolysis method is used as a manufacturing apparatus for hollow particles. The internal combustion spray pyrolysis apparatus used in this production method has a furnace body composed of a vertical tube. A combustion pipe is connected to any part of the outer peripheral surface of the furnace body, and a combustion burner for generating combustion gas is installed in the combustion pipe. A spray device (spray nozzle) for spraying the aqueous solution is installed in the furnace body. The nozzle used here is called a 2-fluid, 3-fluid or 4-fluid nozzle, and an aqueous solution is ejected from the tip at the same time as compressed air to form a mist to form fine particles. The microparticles are dried in the furnace body to form a product. In order to obtain the target specific gravity and particle size, as processing conditions, a certain processing time and processing temperature are required.

In general, in an internal combustion spray pyrolysis apparatus, in addition to gas generated by mist, combustion gas generated by a combustion burner also flows into the furnace body compared to an external heat spray pyrolysis apparatus. The amount of total gas increases. As a result, there is a problem that the gas flow rate in the furnace body increases, and the target processing time (residence time in the furnace) of the particles cannot be ensured. As a result, particles with insufficient melting and low strength are produced. In order to deal with this problem, it is necessary to increase the size of the apparatus or, as in Patent Documents 1 to 3, arrange a plurality of combustion burners to generate a swirling flow in the furnace body and to keep the particles in the furnace body for a long time. can be solved by As a result, temperature unevenness in the furnace body can be suppressed at the same time.

Japanese Patent Application Laid-Open No. 2004-292223 JP 2007-84355 A JP-A-2001-137699

However, even when a swirling flow is generated in the furnace body with a combustion burner, heat exchange between the combustion gas and the particles is not sufficiently performed depending on the positional relationship between the combustion burner and the spray device, resulting in hollow particles with high particle density and low strength. It happened to be.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a spray pyrolysis apparatus capable of producing hollow particles having a low particle density and high strength.

The spray pyrolysis apparatus of the present invention includes a furnace body made of a vertical tube,
at least one combustion tube connected to the outer peripheral surface of the furnace body;
a combustion burner disposed at the end of the combustion tube opposite to the furnace body and generating a flame toward the furnace body;
a spray nozzle arranged on the tube axis at the bottom of the furnace body and spraying an aqueous solution upward;
The combustion tube is arranged so that the discharge direction of the combustion gas from the combustion tube does not intersect the tube axis of the furnace body,
The combustion tube has a constriction at a connection portion with the furnace body,
When viewed from the direction perpendicular to the discharge direction and in the horizontal direction, the intersection point B between the discharge direction and the tube axis of the furnace body is 1/2 of the inner diameter of the furnace body with respect to the tip A of the spray nozzle. The lower limit is two times lower than the inner diameter of the furnace body, and the upper limit is three times the inner diameter of the furnace body.

According to this configuration, by shifting the discharge direction of the combustion gas from the tube axis of the furnace body, when the combustion gas discharged from the combustion tube passes through the furnace body, it does not rise straight up, but forms a swirling flow. It will rise and rise. The mist and particles sprayed onto the furnace main body ride on this swirling flow and rise within the furnace main body, ensuring a sufficient reaction time (processing time). In addition, by arranging the combustion pipe so that the intersection point B between the discharge direction of the combustion gas and the tube axis of the furnace body is located in the above range with respect to the tip A of the spray nozzle, the fuel is sprayed from the spray nozzle. Mist and particles can be sufficiently dispersed by swirling flow. As a result, heat exchange between the combustion gas and the particles is sufficiently performed, and hollow particles having a low particle density and high strength can be produced.

Further, in the spray pyrolysis apparatus of the present invention, a plurality of groups of the combustion tubes are provided at different positions in the vertical direction,
The plurality of combustion tube groups includes a first combustion tube group closest to the spray nozzle in the vertical direction,
When viewed from the horizontal direction perpendicular to the first discharge direction from the combustion tubes belonging to the first combustion tube group, the intersection point B1 between the first discharge direction and the tube axis of the furnace body is the With respect to the tip A of the spray nozzle, the lower limit is 1/2 times the inner diameter of the furnace body and the upper limit is 1/2 times the inner diameter of the furnace body,
Combustion tube groups other than the first combustion tube group may be positioned above the first combustion tube group.

According to this configuration, by interlocking the combustion gas discharged from the plurality of combustion tubes, a sufficient swirling flow can be generated in the furnace body. In addition, by providing a plurality of combustion tubes, it is possible to provide the amount of heat equivalent to the heat dissipated from the furnace body, and to stably ensure the temperature and holding time necessary for synthesizing the hollow particles with good reproducibility.

Further, in the spray pyrolysis apparatus of the present invention, the inner diameter of the discharge port of the restriction may be 1/2 or less of the inner diameter of the furnace main body.

By providing the throttle, the flow velocity of the combustion gas discharged from the combustion pipe can be increased. For example, when the composition is changed and the firing temperature is lowered, the burning amount of the combustion burner decreases, so the flow rate of the combustion gas discharged from the combustion pipe decreases as the amount of combustion gas decreases, and the swirling flow is insufficient. becomes. Therefore, by providing the throttle, even if the amount of combustion gas decreases when the firing temperature is lowered, the flow velocity of the combustion gas discharged from the combustion pipe is maintained, and a sufficient swirling flow can be generated.

Schematic cross-sectional view showing an example of a spray pyrolysis apparatus according to the present invention A plan view showing an example of a spray pyrolysis apparatus according to the present invention. A plan view showing a spray pyrolysis apparatus according to another embodiment A plan view showing a spray pyrolysis apparatus according to another embodiment Cross-sectional schematic diagram showing the positional relationship between the combustion tube and the spray nozzle Cross-sectional schematic diagram showing the positional relationship between multiple combustion tubes and spray nozzles Plan view schematically showing the shape of the furnace body and the combustion tube according to the embodiment A plan view schematically showing the shape of a furnace body and a combustion tube according to a comparative example. A plan view schematically showing the shape of a furnace body and a combustion tube according to a comparative example. Plan view and side view of a spray pyrolysis apparatus according to another embodiment Plan view and side view of a spray pyrolysis apparatus according to another embodiment Plan view and side view of a spray pyrolysis apparatus according to another embodiment

An embodiment of the spray pyrolysis apparatus will be described below with reference to FIGS. 1 to 5. FIG. In each drawing, the dimensional ratio of the drawing and the actual dimensional ratio do not necessarily match, and the dimensional ratio between the drawings does not necessarily match.

FIG. 1 is a schematic cross-sectional view showing an example of a spray pyrolysis apparatus according to the present invention. FIG. 2 is a plan view showing an example of the spray pyrolysis apparatus according to the present invention. The spray pyrolysis apparatus 100 of this embodiment is of an internal combustion type, and includes a furnace body 1 made of a vertical tube and at least one combustion tube 2 connected to the outer peripheral surface of the furnace body 1 .

The materials of the outer walls of the furnace body 1 and the combustion tube 2 are preferably heat-resistant metals such as iron, stainless steel, Inconel, Hastelloy, and titanium. The furnace main body 1 and the combustion tube 2 are substantially cylindrical because they can be connected by a flange, the temperature unevenness in the cross-sectional direction in the furnace main body 1, and the heat dissipation in the cross-sectional direction from the furnace main body 1 and the combustion tube 2. This is preferable in that unevenness can be suppressed.

In addition, the material of the inner wall of the furnace body 1 and the combustion tube 2 may be any material having necessary heat resistance, such as ceramics, metal, brick, and monolithic refractories.

The furnace body 1 consists of a vertical tube extending vertically. The combustion tube 2 is preferably connected to the furnace main body 1 at an angle of 5 to 90 degrees, with the vertical downward direction of 0 degrees. When this angle is 5° or more, the velocity of the swirling flow becomes sufficiently high, the generation of uneven turbulence in the furnace body 1 can be prevented, and variations in the properties of the obtained particles can be suppressed. When the angle is 90° or less, the discharge of hot air is facilitated and heat buildup can be suppressed.

A combustion burner 3 for generating a flame toward the furnace main body 1 is arranged at the end portion 2 a of the combustion tube 2 opposite to the furnace main body 1 . As the fuel used for the combustion burner 3, both liquid fuel and gaseous fuel can be used. Specifically, gaseous fuels such as LPG, city gas, and vaporized organic matter, and liquid fuels such as kerosene, light oil, heavy oil, and recycled oil can be used.

The length of the combustion tube 2 is preferably such that the flame generated from the combustion burner 3 does not come into direct contact with the spray mist. However, if the distance between the flame generated from the combustion burner 3 and the spray mist is too long, the thermal efficiency will be insufficient.

A spray nozzle 4 for spraying the aqueous solution upward is arranged at the bottom of the furnace body 1 . The spray nozzle 4 is arranged on the tube axis 1 c of the furnace body 1 . The spray nozzle 4 is preferably a 2- to 4-fluid nozzle. Compressed air is used as the carrier air, and the spray nozzle 4 is doubled so that an air shield is formed around the spray mist. An aqueous solution may be sprayed. Further, the spray nozzle 4 may be protected by a heat insulating material or the like, if necessary, in consideration of heat resistance.

The combustion tube 2 is connected to the furnace body 1 at the end 2b. A throttle 21 is provided at the connection between the combustion tube 2 and the furnace body 1 . The throttle 21 has a tapered shape, and the inner diameter gradually decreases toward the furnace body 1 . By providing the throttle 21, the flow velocity of the combustion gas discharged from the combustion pipe 2 can be increased. The inner diameter d21 (see FIG. 2) of the discharge port 21a of the throttle 21 is preferably less than half the inner diameter d1 of the furnace body 1 (see FIG. 1).

In addition, the "restriction" in the specification of the present application is not limited to the tapered restriction 21 as in the present embodiment as long as it has a structure capable of increasing the flow velocity near the discharge port of the combustion pipe 2 . The “throttle” may be, for example, a throttle-like structure that increases the flow velocity near the discharge port of the combustion tube 2 by locally reducing the cross-sectional area of the combustion tube 2 .

The throttle 21 may be provided on the end 2b side of the combustion tube 2, and the position of the discharge port 21a of the throttle 21 may be the discharge port of the combustion pipe 2 (see FIG. 3) or the inside of the combustion pipe 2 (see FIG. 4). ), and the inside of the furnace body 1 (see FIG. 2). The material of the diaphragm 21 can be heat-resistant bricks, refractory bricks, monolithic refractories, ceramics, metals, etc., and is appropriately selected depending on the operating temperature, operating environment, and the like.

Although the gradient θ of the throttle 21 is not particularly limited, it depends on the ease of flow of the combustion gas generated from the combustion burner 3 (resistance by the throttle 21) and heat accumulation in the combustion tube 2 (when the gradient θ is large, the resistance of the combustion gas increases. 5° to 75° is preferable in consideration of the fact that heat is accumulated in the combustion tube 2.

As shown in the plan view of FIG. 2, the combustion tubes 2 are arranged so that the discharge direction 20 of the combustion gas from the combustion tubes 2 does not cross the tube axis 1c of the furnace body 1. As shown in FIG. In this embodiment, the discharge direction 20 of the combustion gas is the axial direction of the combustion tube 2 and also the axial direction of the throttle 21 .

By shifting the discharge direction 20 of the combustion gas from the tube axis 1c of the furnace body 1 in this way, when the combustion gas discharged from the combustion tube 2 passes through the furnace body 1, it does not rise straight up, but turns. It causes a current and rises. The mist and particles sprayed onto the furnace main body 1 ride on this swirling flow and rise within the furnace main body 1, ensuring a sufficient reaction time (processing time).

In addition, it is preferable that the discharge direction 20 of the combustion gas is parallel to the tangential direction of the inner peripheral surface of the furnace body 1 . Thereby, a swirling flow can be efficiently generated by the combustion gas.

FIG. 5 is a schematic diagram for explaining the positional relationship between the combustion tube 2 and the spray nozzle 4. As shown in FIG. Note that the diaphragm 21 is omitted in FIG. 5 for convenience of explanation. When viewed in a direction perpendicular to the discharge direction 20 of the combustion gas and in a horizontal direction, specifically a direction perpendicular to the paper surface of FIG. 4, the lower limit is 1/2 times the inner diameter d1 of the furnace body 1, and the upper limit is 3 times the inner diameter d1 of the furnace body 1. If the intersection point B is arranged below the tip A by more than 1/2 times the inner diameter d1, the temperature of the tip of the nozzle (surrounding part after mist ejection) becomes low, and the drying speed of the mist slows down. Collision with the furnace wall and interference between mists, resulting in deterioration of particle quality. If the output of the combustion burner 3 is increased in order to raise the temperature of the tip of the nozzle, the temperature inside the furnace body 1 (in-furnace temperature) becomes too high and the quality of the particles deteriorates.
Further, if the intersection point B is positioned higher than three times the inner diameter d1 with respect to the tip A, the mist and particles sprayed from the spray nozzle 4 cannot be sufficiently dispersed by the swirling flow.

A bag filter for collecting the generated hollow particles can be installed in the upper part of the spray pyrolysis apparatus 100 . In addition, a cyclone may be placed before the bag filter to reduce the load on the bag filter and collect coarse particles and foreign matter.In addition, if a heat exchanger is placed, residual heat can be used and the amount of exhaust gas can be reduced. Therefore, it is preferable. Further, dust removal and purification equipment such as a scrubber may be arranged after the bag filter, if necessary.

By using the spray pyrolysis apparatus 100 of the present embodiment, the sprayed mist and particles ride on the swirling flow and react in the reactor for a long period of time, so that hollow microparticles can be obtained stably and efficiently. In the case of spray pyrolysis using a raw material liquid as a raw material of an inorganic oxide, if the raw material droplets do not come into direct contact with a flame, the drying reaction proceeds first and the mist becomes hollow particles. Subsequently, if the thermal decomposition reaction proceeds, inorganic oxide hollow particles are obtained. Here, examples of inorganic oxides include metal oxides, alumina, silica, calcia, magnesia, oxides composed of aluminum and silicon, and more specifically oxides composed of alumina, silica, aluminum and silicon. oxides, titanium oxides, magnesium oxides, calcium oxides, sodium oxides, potassium oxides, lithium oxides, boron oxides, phosphorous oxides, zirconium oxides, barium oxides, cerium oxides, yttrium oxides, etc. and composite oxides in which these oxides are combined.

Solvents for dissolving or dispersing the raw materials of the elements constituting these oxides include water and organic solvents, but water is preferable from the viewpoint of environmental impact and production costs. or alkali may be added. Examples of acids that can be used include hydrochloric acid, nitric acid, sulfuric acid, and organic acids. Examples of alkalis that can be used include sodium hydroxide, calcium hydroxide, potassium hydroxide, and the like.

Although only one combustion tube 2 is provided in the examples shown in FIGS. 1 to 5, a plurality of combustion tubes 2 may be provided at the same height, and a plurality of groups may be provided at different positions in the vertical direction. (Hereinafter, a plurality of combustion tubes provided at the same height will be referred to as the 0th combustion tube group.). A "group" is also used when only one combustion tube is provided at the same height. A sufficient swirling flow can be generated in the furnace body 1 by interlocking the combustion gases discharged from the plurality of combustion tubes 2 . In addition, by providing a plurality of combustion tubes 2, it is possible to apply the amount of heat equivalent to the heat dissipated from the furnace body 1, and to stably secure the temperature and holding time necessary for synthesizing the hollow particles with good reproducibility.

FIG. 6 shows an example in which two combustion tubes, a first combustion tube 2A and a second combustion tube 2B, are provided. Note that the diaphragm 21 is omitted in FIG. 6 for convenience of explanation. The first combustion tubes 2A belonging to the first combustion tube group are arranged closer to the atomizing nozzles 4 than the second combustion tubes 2B belonging to the second combustion tube group, i.e. the first combustion tube group It is arranged closest to the nozzle 4 in the vertical direction. The discharge direction of combustion gas from the first combustion pipe 2A is defined as a first discharge direction 20A. At this time, when viewed from the direction perpendicular to the first discharge direction 20A and from the horizontal direction, the intersection point B1 between the first discharge direction 20A and the tube axis 1c of the furnace body 1 is located with respect to the tip A of the spray nozzle 4. , the lower limit is 1/2 times lower than the inner diameter d1 of the furnace main body 1, and the upper limit is 1/2 times higher than the inner diameter d1 of the furnace main body 1.

Also, the second combustion tube 2B is arranged above the first combustion tube 2A. The discharge direction of combustion gas from the second combustion pipe 2B is defined as a second discharge direction 20B. At this time, when viewed from the direction perpendicular to the second discharge direction 20B and from the horizontal direction, the intersection point B2 between the second discharge direction 20B and the tube axis 1c of the furnace body 1 is located with respect to the tip A of the spray nozzle 4. , is positioned three times above the inner diameter d1 of the furnace body 1 as an upper limit.

When three or more combustion tube groups are provided, the third and subsequent combustion tube groups are arranged above the second combustion tube group. Further, for example, assuming that the discharge direction of the combustion gas from the combustion tubes belonging to the third combustion tube group is the third discharge direction, when viewed from the direction perpendicular to the third discharge direction and from the horizontal direction, the third The intersection point between the discharge direction and the tube axis 1c of the furnace body 1 is positioned three times above the inner diameter d1 of the furnace body 1 with respect to the intersection point B2. The fourth and subsequent combustion tube groups are similar to the third combustion tube group. That is, if n is an integer of 3 or more, the intersection point B(n) between the (n)th discharge direction and the tube axis 1c of the furnace body 1 is the (n−1)th discharge direction and the tube axis 1c of the furnace body 1. The upper limit is three times the inner diameter d1 of the furnace body 1 with respect to the intersection point B(n−1) with the axis 1c.

Specific examples and the like are shown below to describe the present invention in more detail, but the present invention is not limited to the aspects of these examples.

Examples 1-4
A spray pyrolysis apparatus having a furnace body 1 and a combustion tube 2 shown in FIG. 7 was installed. The inner diameter of the furnace body 1 was set to 500 mm. The inner diameter of the combustion tube 2 was set to 500 mm, and the inner diameter of the combustion tube 2 in the vicinity of the outlet was set to 250 mm due to the throttle structure (throttle length: 400 mm, gradient: 17°). As for the material of the combustion tube 2, steel was used as the base material, and a monolithic refractory was used as the refractory material for the lining.

Comparative Examples 1-4
A spray pyrolysis apparatus having a furnace body 1 and a combustion tube 2 shown in FIGS. 8 and 9 was installed. The inner diameter of the furnace body 1 was set to 500 mm. The internal diameter of the combustion tube 2 was 500 mm or 250 mm, and no restriction structure was provided.

Next, 1992 g of tetraethyl orthosilicate, 131 g of aluminum nitrate nonahydrate, 455 g of magnesium nitrate hexahydrate, 516 g of calcium nitrate tetrahydrate, 1666 g of sodium tetraborate decahydrate, and 1 L of concentrated nitric acid are added to 100 L of ion-exchanged water. was put into the solution tank and stirred. The supplied raw material solution was sprayed in mist form through the spray nozzle 4 by the liquid-sending pump, and passed through the furnace main body 1 .

As for the combustion tube 2, at least one combustion tube (first combustion tube) was provided, and up to three combustion tubes (first to third combustion tubes) were provided. The discharge direction of the first combustion tube and the tube axis 1c of the furnace body 1 when the installation position of each combustion tube 2 with respect to the tip of the spray nozzle 4, that is, the position of the tip A of the spray nozzle 4 is set to "0". (B1 in FIG. 6), the position of the intersection (B2 in FIG. 6) between the discharge direction of the second combustion tube and the tube axis 1c of the furnace body 1, the discharge direction of the third combustion tube and the furnace body The positions of intersections (not shown in FIG. 6) with the tube axis 1c of 1 are as shown in Table 1. In Table 1, "+" indicates upward and "-" indicates downward. In addition, although the third combustion pipe is provided in Example 4 and Comparative Example 4, the third combustion pipe is provided at the same height as the second combustion pipe, and the third combustion pipe and the second combustion pipe belongs to the second group of combustion tubes.

The combustion burner 3 was an LPG burner, and the furnace temperature was controlled to 900° C. by the amount of burning of the LPG burner. The raw material solution was sprayed from the spray nozzle 4 at 30 L/h, the particles were quenched to 300° C. by cooling air at the outlet of the furnace body 1, and the hollow particles were recovered by the subsequent bag filter.

The collected hollow particles were evaluated as follows. Table 2 shows the evaluation results.
・Measurement of average particle size The average particle size of the inorganic oxide hollow particles was obtained by using a Microtrac (manufactured by Nikkiso Co., Ltd.) as a particle size distribution measuring device to create a volume-based particle size distribution in accordance with JIS R 1629. , the particle diameter (d50) corresponding to 50% of the integrated distribution curve was determined.

- Measurement of Particle Density The particle density of the inorganic oxide hollow particles was measured according to JIS R 1620 with a dry automatic densitometer "Accupic" (manufactured by Shimadzu Corporation).

- Measurement of particle strength Particle strength was measured by the following powder pressing method.
(1) A sample was prepared by mixing inorganic oxide hollow particles and ethanol at a weight ratio of 4:1.
(2) The sample was placed in a pressure former, and a predetermined pressure (10 MPa, 20 MPa, 30 MPa) was applied with a hydraulic press.
(3) Leave for 1 minute while a predetermined pressure is applied.
(4) The sample was removed from the pressure former and dried at 80°C for 2 hours.
(5) The density of the inorganic oxide hollow particles after pressurization was measured with a density measuring machine (Accupic, manufactured by Shimadzu Corporation).
Then, from the density of the inorganic oxide hollow particles before and after pressurization, the residual ratio for each predetermined pressure was calculated by the following formula, and the pressure at 50% residual was read from the graph of residual ratio and applied pressure.
Survival rate P [%] = (1-ρ/y)/ρ x (1/x-1/y) x 100
(Wherein, ρ indicates the density after pressing, y indicates the true density of the hollow shell, and x indicates the density before pressing.)
The true density of the hollow shell was measured with a density measuring instrument after heating at the melting point or higher for 6 hours in a box-type electric furnace and cooling in order to remove voids.

From Tables 1 and 2, in Examples 1 to 4, the throttle structure and the installation of the first combustion tube (combustion burner) at an appropriate position gave an appropriate value for the flow velocity of the combustion gas, so a swirling flow was formed in the furnace body. occurred and the residence time was secured. As a result, hollow particles with low particle density and high particle strength could be produced.

The spray pyrolysis apparatus 100 is not limited to the configuration of the embodiment described above, nor is it limited to the effects described above. Further, the spray pyrolysis apparatus 100 can of course be modified in various ways without departing from the gist of the present invention. For example, each configuration, each method, etc. of the above-described multiple embodiments may be arbitrarily adopted and combined, and further, one or more of the configurations, methods, etc. according to the various modifications described below may be arbitrarily selected. , of course, may be employed in the configurations, methods, and the like according to the above-described embodiments.

In the above-described embodiment, the combustion tube 2 is connected to the furnace main body 1 at an angle of 90°, and the throttle 21 is arranged so that the axial center of the throttle 21 coincides with the tube axis of the combustion tube 2 as shown in FIG. 10(a). Consistent taper, but not limited to. For example, the ejection port 21a of the diaphragm 21 may have a square shape as shown in FIG. 10B, or may have a polygonal shape such as a hexagon. Further, for example, as shown in FIG. 10(c), the combustion tube 2 may be connected to the furnace body 1 at an angle of less than 90°. Also, for example, as shown in FIG.

When a plurality of combustion tubes are provided, they may be provided at different heights or may be provided at the same height. When a plurality of combustion tubes are provided at the same height, the plurality of combustion tubes are provided at intervals in the circumferential direction of the furnace body 1 . In the example shown in FIG. 11 , the three combustion tubes 2 are provided at different heights and are provided at equal intervals in the circumferential direction of the furnace body 1 .

In the above-described embodiment, one combustion tube 2, one first combustion tube 2A, and one second combustion tube 2B are provided, but the present invention is not limited to this. For example, a plurality of combustion tubes 2 may be provided at the same height. Similarly, a plurality of first combustion tubes 2A may be provided at the same height.

Further, for example, as shown in FIG. 12, the plurality of combustion tubes 2 may be connected to the furnace body 1 at an angle of less than 90°.

REFERENCE SIGNS LIST 100: spray pyrolysis device 1: furnace body 1c: tube axis of furnace body 2: combustion tube 2A: first combustion tube 2B: second combustion tube 2a: end of combustion tube 2b: end of combustion tube 3 : Combustion burner 4 : Spray nozzle 20 : Combustion gas discharge direction 20A : First discharge direction 20B : Second discharge direction 21 : Restriction 21a : Restriction discharge port A : Tip of spray nozzle B : Combustion gas discharge direction and the tube axis of the furnace body B1: intersection of the first discharge direction and the tube axis of the furnace body B2: intersection of the second discharge direction and the tube axis of the furnace body d1: inner diameter of the furnace body d21: throttle Inner diameter of outlet of

Claims (4)

a furnace body consisting of a vertical tube;
at least one combustion tube connected to the outer peripheral surface of the furnace body;
a combustion burner disposed at the end of the combustion tube opposite to the furnace body and generating a flame toward the furnace body;
a spray nozzle arranged on the tube axis at the bottom of the furnace body and spraying an aqueous solution upward;
The combustion tube is arranged so that the discharge direction of the combustion gas from the combustion tube does not intersect the tube axis of the furnace body,
The combustion tube has a constriction at a connection portion with the furnace body,
When viewed from the direction perpendicular to the discharge direction and in the horizontal direction, the intersection point B between the discharge direction and the tube axis of the furnace body is 1/2 of the inner diameter of the furnace body with respect to the tip A of the spray nozzle. A spray pyrolysis apparatus, wherein the lower limit is twice the lower limit and the upper limit is three times the inner diameter of the furnace body. A plurality of groups of the combustion tubes are provided at different positions in the vertical direction,
The plurality of combustion tube groups includes a first combustion tube group closest to the spray nozzle in the vertical direction,
When viewed from the horizontal direction perpendicular to the first discharge direction from the combustion tubes belonging to the first combustion tube group, the intersection point B1 between the first discharge direction and the tube axis of the furnace body is the With respect to the tip A of the spray nozzle, the lower limit is 1/2 times the inner diameter of the furnace body and the upper limit is 1/2 times the inner diameter of the furnace body,
2. The spray pyrolysis apparatus according to claim 1, wherein combustion tube groups other than said first combustion tube group are positioned above said first combustion tube group. 3. The spray pyrolysis apparatus according to claim 1 or 2, wherein the inner diameter of the discharge port of said restriction is 1/2 or less of the inner diameter of said furnace body. The spray pyrolysis apparatus according to any one of claims 1 to 3, wherein the gradient θ of said restriction is 5 to 75°.

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