阅读说明：本技术 一种喷雾燃烧合成纳米颗粒的系统 (System for synthesizing nano-particles by spray combustion ) 是由 赵海波 袁兴 徐祖伟 于 2020-12-25 设计创作，主要内容包括：本发明属于纳米材料合成相关技术领域,其公开了一种喷雾燃烧合成纳米颗粒的系统,系统包括相连接的湍流燃烧器及注射泵,湍流燃烧器包括第一圆管、第二圆管、多个气体喷嘴、第三圆管、第四圆管、毛细针管及活动喷嘴；第一圆管与第二圆管之间设置有鞘气管路；气体喷嘴设置在第二圆管与第三圆管之间；第三圆管与第四圆管之间设置有预混气管路；第四圆管形成有收容孔,活动喷嘴活动地设置在收容孔内；活动喷嘴与第四圆管之间形成第一分散气管路；毛细针管设置在活动喷嘴内。本发明能加大地扩展颗粒的结构和组分,液态前驱体的流速可调节范围大幅提升,能显著增加纳米颗粒的产率,能够达到火焰纳米颗粒合成的工业化放大。(The invention belongs to the technical field related to the synthesis of nano materials, and discloses a system for synthesizing nano particles by spray combustion, which comprises a turbulent burner and an injection pump which are connected, wherein the turbulent burner comprises a first round pipe, a second round pipe, a plurality of gas nozzles, a third round pipe, a fourth round pipe, a capillary tube and a movable nozzle; a sheath gas pipeline is arranged between the first round pipe and the second round pipe; the gas nozzle is arranged between the second round pipe and the third round pipe; a premixed gas pipeline is arranged between the third round pipe and the fourth round pipe; the fourth circular tube is formed with an accommodating hole, and the movable nozzle is movably arranged in the accommodating hole; a first dispersed air pipeline is formed between the movable nozzle and the fourth circular pipe; the capillary needle tube is arranged in the movable nozzle. The invention can enlarge and expand the structure and the components of the particles, greatly improve the adjustable range of the flow rate of the liquid precursor, obviously increase the yield of the nanoparticles and achieve the industrial amplification of flame nanoparticle synthesis.)

1. A system for spray combustion synthesis of nanoparticles, comprising:

the system comprises a turbulent burner, an injection pump, a telescopic igniter and a stainless steel isolation cover, wherein the injection pump is connected with the turbulent burner, the stainless steel isolation cover is arranged above the turbulent burner, and the telescopic igniter is arranged between the turbulent burner and the stainless steel isolation cover;

the turbulent burner comprises a first round pipe, a second round pipe, a plurality of gas nozzles, a third round pipe, a fourth round pipe, a capillary tube and a movable nozzle, wherein the second round pipe is arranged in the first round pipe; a sheath gas pipeline is arranged between the first round pipe and the second round pipe and is used for allowing sheath gas to pass through so as to enter a gap between the first round pipe and the second round pipe; the gas nozzle is arranged between the second round pipe and the third round pipe; a premixed gas pipeline is arranged between the third round pipe and the fourth round pipe; a first round hole is formed at one end of the fourth round pipe, a tapered hole is formed at the other end of the fourth round pipe, the wall of the large end of the tapered hole is connected with the wall of the first round hole, the first round hole and the tapered hole together form an accommodating hole, and the movable nozzle is movably arranged in the accommodating hole; a first dispersion air pipeline is formed between the movable nozzle and the fourth circular pipe; the capillary needle tube is arranged in the movable nozzle and penetrates through the movable nozzle; wherein, the end of the capillary needle tube far away from the stainless steel isolation cover is connected with the injection pump.

2. The system for spray combustion synthesis of nanoparticles of claim 1, wherein: changing the size and pressure of the first dispersion gas line outlet by adjusting the attitude of the movable nozzle relative to the tapered hole.

3. The system for spray combustion synthesis of nanoparticles of claim 1, wherein: the outer diameter of the first round pipe, the outer diameter of the second round pipe, the outer diameter of the third round pipe and the outer diameter of the fourth round pipe are reduced in sequence.

4. The system for spray combustion synthesis of nanoparticles of claim 1, wherein: the system further comprises a clamp, the clamp is arranged between the second round pipe and the third round pipe, the gas nozzle is arranged on the clamp, and the pose of the gas nozzle is adjusted through the clamp.

5. The system for spray combustion synthesis of nanoparticles of claim 1, wherein: the precursor is sucked by the injection pump to enter the capillary tube and is sprayed and atomized by the capillary tube; the premixed gas is ignited by the telescopic igniter to form premixed flame, the atomized precursor is further diffused by the dispersed gas and is directly ignited by the premixed flame or the telescopic igniter to form stable turbulent flame; the gas nozzle sprays oxygen-containing mixed gas to perform secondary air supplement on the flame.

6. The system for spray combustion synthesis of nanoparticles of any one of claims 1-5, wherein: the system also comprises glass fiber filter paper and an air pump, wherein the glass fiber filter paper is arranged at one end of the stainless steel isolation hood, which is far away from the turbulent burner, a cover plate is arranged on the stainless steel isolation hood, and the glass fiber filter paper is positioned between the cover plate and the stainless steel isolation hood; the air pump is connected to the glass fiber filter paper through a pipeline; the air pump draws the particles to flow onto the glass fiber filter paper for collection.

7. The system for spray combustion synthesis of nanoparticles of any one of claims 1-5, wherein: the number of the capillary needle tubes is at least four, and the at least four capillary needle tubes are uniformly distributed around the central axis of the movable nozzle.

8. The system for spray combustion synthesis of nanoparticles of claim 7, wherein: the movable nozzle is provided with an internal dispersing air pipeline, and the central axis of the internal dispersing air pipeline is superposed with the central axis of the movable nozzle; at least four of the capillary tubes are arranged around the internal dispersion gas line.

9. The system for spray combustion synthesis of nanoparticles of claim 7, wherein: at least four of the capillary tubes can each be individually controlled.

10. The system for spray combustion synthesis of nanoparticles of claim 8, wherein: the central axis of the first circular tube, the central axis of the third circular tube, the central axis of the fourth circular tube, and the central axis of the internal dispersed air line coincide.

Technical Field

The invention belongs to the technical field related to the synthesis of nano materials, and particularly relates to a system for synthesizing nano particles by spray combustion.

Background

The nano material has wide application in the fields of catalysis, medicine, materials, electronics and the like, wherein the preparation mode of the nano particle gradually becomes a focus of attention due to the unique physical and chemical characteristics of the nano particle. Flame spray combustion is a high-flux nano material synthesis process developed in recent years, and laboratory-scale equipment can achieve the yield of more than one hundred grams of nano particles per hour, so that the method is very suitable for industrial scale-up large-scale production and is widely used for preparing oxide particles with various structures and sizes.

Compared with the traditional wet chemical synthesis method, the flame spray combustion method directly utilizes the energy of flame, is fast synthesized in one step, has no redundant post-treatment steps (such as aging, drying, annealing and the like), does not produce waste liquid and waste residue in the generation process, and has the characteristics of energy conservation, environmental protection and high efficiency; in the flame synthesis process, the multi-component metal oxide can be mixed on an atomic scale, and the active phase on the surface of the nano material has extremely high dispersity; the active phase can still keep high dispersion without calcination process, so that the effective loading capacity of the metal oxide can be increased remarkably; by controlling turbulent flame, high-flux synthesis of functional nanoparticles can be realized; the properties of the nanoparticles can be adjusted by operating conditions such as precursor type, concentration, flow rate, solvent type, dispersion gas flow rate, and other process conditions. Therefore, the system for synthesizing the nano-particles by flame spray combustion can greatly expand the application range of the flame synthesis mode and open up a new way for preparing functional nano-materials. At present, in a common experimental-scale spray pyrolysis combustion synthesis nanoparticle device, because an air inlet channel singly limits the flow rate of oxygen, the device has the defects of particle agglomeration and sintering, organic matter residue on particles, low yield and the like.

Disclosure of Invention

Aiming at the defects or improvement requirements of the prior art, the invention provides a system for synthesizing nanoparticles by spray combustion, wherein a turbulent burner is adopted to form stable turbulent flame, a precursor is directly sprayed and atomized at high pressure, combustion atmospheres with different equivalence ratios are formed by matching with a dispersing gas, and secondary air supply equipment is added, so that the growth environment of the nanoparticles in a high-temperature region can be further regulated and controlled, the particle size distribution, the appearance size and the crystal phase purity of the nanoparticles can be accurately controlled, the structure and the components of the particles can be greatly expanded, the flow speed adjustable range of a liquid precursor is greatly improved, the yield of the nanoparticles can be remarkably increased, and the industrial amplification of flame nanoparticle synthesis can be achieved.

To achieve the above objects, according to one aspect of the present invention, there is provided a system for spray combustion synthesis of nanoparticles, the system comprising a turbulent burner, an injection pump, a telescopic igniter, and a stainless steel shield, the injection pump being connected to the turbulent burner, the stainless steel shield being disposed above the turbulent burner, the telescopic igniter being disposed between the turbulent burner and the stainless steel shield;

the turbulent burner comprises a first round pipe, a second round pipe, a plurality of gas nozzles, a third round pipe, a fourth round pipe, a capillary tube and a movable nozzle, wherein the second round pipe is arranged in the first round pipe; a sheath gas pipeline is arranged between the first round pipe and the second round pipe and is used for allowing sheath gas to pass through so as to enter a gap between the first round pipe and the second round pipe; the gas nozzle is arranged between the second round pipe and the third round pipe; a premixed gas pipeline is arranged between the third round pipe and the fourth round pipe; a first round hole is formed at one end of the fourth round pipe, a tapered hole is formed at the other end of the fourth round pipe, the wall of the large end of the tapered hole is connected with the wall of the first round hole, the first round hole and the tapered hole together form an accommodating hole, and the movable nozzle is movably arranged in the accommodating hole; a first dispersion air pipeline is formed between the movable nozzle and the fourth circular pipe; the capillary needle tube is arranged in the movable nozzle and penetrates through the movable nozzle; wherein, the end of the capillary needle tube far away from the stainless steel isolation cover is connected with the injection pump.

Further, the size and pressure of the first dispersion air pipe outlet are changed by adjusting the attitude of the movable nozzle with respect to the tapered hole.

Further, the outer diameter of the first round tube, the outer diameter of the second round tube, the outer diameter of the third round tube and the outer diameter of the fourth round tube decrease in sequence.

Further, the system also comprises a clamp, the clamp is arranged between the second round pipe and the third round pipe, the gas nozzle is arranged on the clamp, and the posture of the gas nozzle is adjusted through the clamp.

Further, the precursor is sucked by the injection pump to enter the capillary tube and is sprayed and atomized by the capillary tube; the premixed gas is ignited by the telescopic igniter to form premixed flame, the atomized precursor is further diffused by the dispersed gas and is directly ignited by the premixed flame or the telescopic igniter to form stable turbulent flame; the gas nozzle sprays oxygen-containing mixed gas to perform secondary air supplement on the flame.

Furthermore, the system also comprises glass fiber filter paper and an air pump, wherein the glass fiber filter paper is arranged at one end, away from the turbulent burner, of the stainless steel isolation hood, a cover plate is arranged on the stainless steel isolation hood, and the glass fiber filter paper is positioned between the cover plate and the stainless steel isolation hood; the air pump is connected to the glass fiber filter paper through a pipeline; the air pump draws the particles to flow onto the glass fiber filter paper for collection.

Furthermore, the number of the capillary needle tubes is at least four, and the at least four capillary needle tubes are uniformly distributed around the central axis of the movable nozzle.

Furthermore, the movable nozzle is provided with an internal dispersion air pipeline, and the central axis of the internal dispersion air pipeline is superposed with the central axis of the movable nozzle; at least four of the capillary tubes are arranged around the internal dispersion gas line.

Further, at least four of the capillary tubes can each be individually controlled.

Further, a central axis of the first round tube, a central axis of the third round tube, a central axis of the fourth round tube, and a central axis of the internal dispersion air line coincide.

In general, compared with the prior art, the system for synthesizing nanoparticles by spray combustion provided by the invention mainly has the following beneficial effects:

1. the concentration of the nano particles in the high-temperature area can be diluted by secondary air supply, and the agglomeration and sintering of the particles are reduced; eliminating unburned gaseous precursor and organic matter adsorbed on the surface of the particle in primary combustion; the particles can be calcined for the second time to control the crystal phase and the particle size distribution degree of the nano material; the proportion and the variety of the liquid phase precursor are further increased by the secondary supplement of the oxygen, and the structure and the components of the nano particles are widened.

2. Due to secondary oxygen supply, the supply flow rate of the liquid phase precursor can be further improved, and the yield of the nano particles can be obviously increased; the secondary air supply equipment can effectively prevent the diffusion of the particles in the high-temperature area and can obviously reduce the deposition of the particles on the stainless steel isolation cover; the control of the oxygen-fuel equivalence ratio in spray combustion synthesis is further enhanced by flexibly adjusting the oxygen concentration in the dispersion gas and the secondary air supply.

3. The proportion and the variety of the liquid-phase metal organic precursor are increased by the two or more precursor pipelines, and the structure and the components of the nano particles are widened; the introduction of the inner and outer double-layer combustion-supporting gas can further improve the supply flow of the liquid phase precursor and can obviously increase the yield of the nano particles.

4. Let in inside outside combustion-supporting gas and can greatly avoid the sintering and the reunion of granule, outside combustion-supporting gas intercrossing forms coniform blast wall in order to prevent that the nanoparticle from diffusing to the stainless steel cage all around on, inside combustion-supporting gas can spray pure argon gas in order to quench turbulent flame, reduces the reunion and the sintering phenomenon of granule, increases nano material's specific surface area.

Drawings

FIG. 1 is a schematic diagram of a system for spray combustion synthesis of nanoparticles provided in example 1 of the present invention;

FIG. 2 is a schematic structural diagram of a burner of the system for spray combustion synthesis of nanoparticles of FIG. 1;

FIG. 3 is a schematic diagram of a system for spray combustion synthesis of nanoparticles provided in example 2 of the present invention;

fig. 4 is a schematic structural view of a burner of the system for synthesizing nanoparticles by spray combustion in fig. 3. The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein: the method comprises the following steps of 1-a sheath gas pipeline, 2-a gas nozzle, 3-premixed flame, 4-a dispersed gas pipeline, 5-a precursor pipeline, 6-an injection pump, 7-a capillary needle tube, 8-a telescopic igniter, 9-a stainless steel shield, 10-glass fiber filter paper, 11-an air pump, 12-a clamp and 13-a movable nozzle.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1

Referring to fig. 1 and 2, in the system for synthesizing nanoparticles by spray combustion according to embodiment 1 of the present invention, a turbulent burner is used to form a stable turbulent flame, and the precursor is directly sprayed and atomized to form a combustion atmosphere with different equivalence ratios by matching with a dispersion gas. The secondary air supplement component is added to further regulate and control the growth environment of the nano particles in a high-temperature area so as to realize the precise control of the particle size distribution, the appearance size and the crystal phase purity of the nano particles and greatly expand the structure and the components of the particles. Due to the further supplement of oxygen, the adjustable range of the flow rate of the liquid precursor is greatly improved, the yield of the nanoparticles can be obviously increased, and the industrial amplification of flame nanoparticle synthesis can be achieved. The liquid precursor is injected into the spray by an injection pump through a capillary, and the spray is ignited and diffused by oxygen-containing dispersion gas. Through adjusting the angle of the gas nozzle, secondary gas supply is carried out in a flame high-temperature area, and heating and combustion of the subareas are realized. Wherein, can adjust the oxygen concentration in the secondary tonifying qi to form different oxygen-fuel equivalence ratios, the system has the advantages of reducing agglomeration and sintering of particles, no need of secondary calcination, high yield and the like.

The system comprises a turbulent burner, an injection pump 6, a telescopic igniter 8, a stainless steel isolation cover 9, glass fiber filter paper 10, an air pump 11 and a clamp 12. The clamp 12 is connected to the turbulent burner, the stainless steel isolation cover 9 is arranged above the turbulent burner, and the telescopic igniter 8 is positioned between the stainless steel isolation cover 9 and the turbulent burner. One end, far away from the turbulent burner, of the stainless steel isolation hood 9 is provided with glass fiber filter paper 10, the cover plate is arranged on the stainless steel isolation hood 9, and the glass fiber filter paper 10 is located between the cover plate and the stainless steel isolation hood 9. The air pump 11 is connected to the glass fiber filter paper 10 through a pipe. The injection pump 6 is connected to the turbulent burner. Wherein, be provided with cooling duct on the apron, cooling duct is used for supplying cooling water circulation to cool off.

Turbulent burner includes first pipe, second pipe, a plurality of gas nozzle 2, third pipe, fourth pipe, capillary tube 7 and movable nozzle 13, the second pipe sets up in the first pipe, the third pipe sets up in the second pipe, the fourth pipe sets up in the third pipe. The outer diameter of the first round pipe, the outer diameter of the second round pipe, the outer diameter of the third round pipe and the outer diameter of the fourth round pipe are reduced in sequence.

First pipe with be provided with sheath gas pipeline 1 between the second pipe, sheath gas pipeline 1 is used for supplying the sheath gas to pass through in order to get into first pipe with in the clearance between the second pipe. The gas nozzle 2 is arranged between the second round pipe and the third round pipe. The clamp 12 is arranged between the second round pipe and the third round pipe, the gas nozzle 2 is arranged on the clamp 12, and the posture of the gas nozzle 2 can be adjusted through the clamp 12. The third pipe with be provided with the gas pipeline in advance between the fourth pipe, the gas pipeline in advance is used for supplying the gas circulation in advance to mix in advance to supply in advance the gas entering the third pipe with in the clearance between the fourth pipe.

One end of the fourth round pipe is formed with a first round hole, the other end of the fourth round pipe is formed with a tapered hole, the big end hole wall of the tapered hole is connected with the hole wall of the first round hole, the first round hole and the tapered hole form an accommodating hole, and the movable nozzle 13 is movably arranged in the accommodating hole.

A dispersed gas pipeline 4 is formed between the movable nozzle 13 and the fourth circular tube, and the size and the pressure of an outlet of the dispersed gas pipeline 4 are changed by adjusting the posture of the movable nozzle 13 relative to the tapered hole, so that the entering amount of the dispersed gas is adjusted.

The capillary tube 7 is arranged in the movable nozzle 13 and penetrates through the movable nozzle 13. One end of the capillary tube 7, which is far away from the stainless steel isolation cover 9, is connected to the injection pump 6, and the injection pump 6 is used for sucking the precursor.

In this embodiment, a cooling pipe is also provided in the movable nozzle 13, and cooling water is introduced into the cooling pipe to cool the movable nozzle 13; the central axis of the first circular tube, the central axis of the second circular tube, the central axis of the third circular tube, the central axis of the fourth circular tube and the central axis of the capillary needle tube 7 are overlapped; the plurality of gas nozzles 2 are uniformly distributed around the central axis of the fourth circular tube, and the number of the gas nozzles 2 is four, it can be understood that in other embodiments, the number of the gas nozzles 2 can be increased or decreased according to actual needs.

The spray combustion synthesis of the nanoparticles mainly comprises the preparation of liquid precursors, the spray atomization and turbulent flame combustion of precursor solutions and the collection of the nanoparticles. According to the structure and the components of the target nano-particles, corresponding metal organic salts are selected as metal precursors. Because the high gasification decomposition temperature of the metal acetate and the metal nitrate can cause poor uniformity of the size of the nano particles, corresponding metal 2-ethylhexanoate and acetylacetone salt should be selected; and simultaneously, selecting organic fuel with better solubility according to the types of the metal organic salts, wherein the organic fuel comprises dimethylbenzene, ethanol, butanol or propionic acid. Due to the addition of oxygen in the secondary make-up gas, the metal ion concentration range can significantly exceed the upper concentration limit of conventional burners. Dissolving metal organic salt in organic fuel and carrying out ultrasonic treatment to ensure complete dissolution and uniform mixing of the metal organic salt.

The precursor is sucked by the injection pump 6 and enters the precursor pipeline, and then enters the capillary tube 7, and is sprayed and atomized by the capillary tube 7, the premixed gas is ignited by the telescopic igniter 8 to form premixed flame, and the atomized precursor is further diffused by the dispersed gas and is directly ignited by the premixed flame or the telescopic igniter 8 to form stable turbulent flame. The gas nozzle 2 sprays oxygen-containing mixed gas to perform secondary air supplement on the spray flame, and the angle of the gas nozzle 2 is adjusted to converge the gas in a flame combustion area, so that the aims of oxygen supplement and secondary calcination are fulfilled. The outermost sheath gas of the burner is composed of inert gas, so that the burner can isolate the outside air and protect the stability of the burning flame. The nanoparticles at high temperature are protected by a stainless steel shield 9 from diffusion into the surrounding environment. The air pump 11 draws the particles to flow onto the glass fiber filter paper 10 for collection.

Example 2

Referring to fig. 3 and 4, in the system for synthesizing nanoparticles by spray combustion provided in embodiment 2 of the present invention, a turbulent burner is selected to form a stable turbulent flame, and the precursor is directly atomized by high-pressure injection and matched with combustion-supporting gas to form a combustion atmosphere with different equivalence ratios. And a plurality of precursor pipelines are added, so that the growth environment of the nano particles in a high-temperature region can be further regulated and controlled, the particle size distribution, the appearance size and the crystal phase purity of the nano particles can be accurately controlled, and the structure and the components of the particles can be greatly expanded. The adjustable range of the flow velocity of the liquid precursor is greatly improved, the yield of the nanoparticles can be obviously increased, and the industrial amplification of flame nanoparticle synthesis can be achieved. The liquid precursor is sprayed through a capillary needle tube by a high-pressure injection pump, and the spray is ignited and diffused by internal combustion-supporting gas and external combustion-supporting gas which are composed of oxygen and argon. The oxygen composition ratio in the combustion-supporting gas can be adjusted to form different oxygen fuel equivalence ratios. The time and the area of the precursor spray converged on the flame are changed by adjusting the height of the capillary tube. More than two precursor pipelines can form at least more than two different metal precursor solutions, can form the doping and loading of multi-element metal oxides and multiple elements, and greatly expands the structure and the components of the nano particles. The method has the advantages of reducing agglomeration and sintering of particles, increasing the structure and components of the particles, and being high in yield.

The system comprises a turbulent burner, an injection pump, a telescopic igniter, a stainless steel isolation cover, glass fiber filter paper and an air pump, wherein the stainless steel isolation cover is arranged above the turbulent burner, and the telescopic igniter is arranged between the stainless steel isolation cover and the turbulent burner. The glass fiber filter paper is arranged at one end, far away from the turbulent burner, of the stainless steel isolation hood, a cover plate is arranged on the stainless steel isolation hood, and the glass fiber filter paper is arranged between the cover plate and the stainless steel isolation hood. The air pump was attached to the fiberglass filter paper. Wherein, be provided with cooling duct on the apron, cooling duct is used for supplying cooling water circulation to cool off.

The turbulent burner comprises a first round pipe, a third round pipe, a fourth round pipe, at least four capillary tubes and a movable nozzle, wherein the third round pipe is arranged in the first round pipe, and the fourth round pipe is arranged in the third round pipe. The outer diameter of the first circular tube, the outer diameter of the third circular tube and the outer diameter of the fourth circular tube are reduced in sequence.

The first round pipe with be provided with sheath gas pipeline between the third round pipe, sheath gas pipeline is used for supplying sheath gas to pass through in order to get into first round pipe with in the clearance between the third round pipe. The third pipe with be provided with the gas pipeline in advance between the fourth pipe, the gas pipeline in advance is used for supplying the gas circulation in advance to mix in advance to supply in advance the gas entering the third pipe with in the clearance between the fourth pipe.

One end of the fourth round pipe is provided with a first round hole, the other end of the fourth round pipe is provided with a conical hole, the wall of the big end of the conical hole is connected with the wall of the first round hole, the first round hole and the conical hole form an accommodating hole, and the movable nozzle is movably arranged in the accommodating hole.

A first dispersion air pipeline is formed between the movable nozzle and the fourth circular pipe, the size and the pressure of an outlet of the first dispersion air pipeline are changed by adjusting the posture of the movable nozzle relative to the conical hole, and then the entering amount of dispersion air is adjusted. Wherein the first dispersion air pipeline is also called as an external dispersion air pipeline.

At least four of the capillary needle tubes are arranged in the movable nozzle and penetrate through the movable nozzle. One end of the capillary needle tube, which is far away from the stainless steel isolation cover, is connected to the injection pump, and the injection pump is used for pumping the precursor. The at least four capillary needle tubes are uniformly distributed around the central axis of the movable nozzle, the movable nozzle is provided with an internal dispersed air pipeline, and the central axis of the internal dispersed air pipeline is superposed with the central axis of the movable nozzle.

In the present embodiment, a cooling pipeline is also provided in the movable nozzle, and cooling water is introduced into the cooling pipeline to cool the movable nozzle; the central axis of the first round tube, the central axis of the third round tube, the central axis of the fourth round tube and the central axis of the internal dispersed air pipeline are overlapped; the number of the capillary tubes is four, and it can be understood that in other embodiments, the number of the capillary tubes can be increased or decreased according to actual needs.

The capillary tubes, the corresponding injection pumps and the like can be independently controlled, for example, four capillary tubes can be filled with the same precursor solution, and the yield of the nano particles is directly increased by four times compared with that of the traditional single-nozzle flame synthesis equipment. More than four capillary tubes can form more than two different metal precursor solutions, can form the doping and loading of multi-element metal oxides and various elements, and greatly expands the structure and components of the nano particles.

The spray combustion synthesis of the nanoparticles mainly comprises the preparation of liquid precursors, the spray atomization and turbulent flame combustion of precursor solutions and the collection of the nanoparticles. According to the structure and the components of the target nano-particles, corresponding metal organic salts are selected as metal precursors. Because the high gasification decomposition temperature of the metal acetate and the metal nitrate can cause poor uniformity of the size of the nano particles, the corresponding metal 2-ethylhexanoate and acetylacetone salts are selected, and organic fuels with better solubility, including xylene, ethanol, butanol or propionic acid, are selected according to the types of the metal organic salts. Since the oxygen-containing combustion-supporting gas is introduced both inside and outside, the metal ion concentration range can significantly exceed the upper concentration limit of the conventional burner. Dissolving metal organic salt in organic fuel and carrying out ultrasonic treatment to ensure complete dissolution and uniform mixing of the metal organic salt. The premixed gas is ignited by the telescopic igniter to form premixed flame; the precursor solution flows through the capillary needle tube by the injection pump to be sprayed and atomized and is ignited by the premixed flame to form stable turbulent flame. The angles of the four capillary needle tubes are adjusted to be converged in different flame combustion areas. The outermost sheath gas of the burner is composed of inert gas, so that the burner can isolate the outside air and protect the stability of the burning flame. The nanoparticles at high temperature are protected by a stainless steel shield from diffusion into the surrounding environment. The air pump draws the particles to flow onto the glass fiber filter paper for collection.

It can be understood that the embodiment 1 and the embodiment 2 of the present invention can be combined to obtain a new system for synthesizing nano particles by spray combustion, for example, the movable nozzle of the embodiment 1 is replaced by the movable nozzle of the embodiment 2, and the arrangement mode of a plurality of capillary tubes is applied to the embodiment 1.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.