CN209997611U

CN209997611U - apparatus for producing nano material from liquid or gaseous precursor

Info

Publication number: CN209997611U
Application number: CN201821618119.5U
Authority: CN
Inventors: 郑小勇
Original assignee: Zhangjiagang Hengde New Material Technology Co Ltd
Current assignee: Zhangjiagang Hengde New Material Technology Co Ltd
Priority date: 2018-10-03
Filing date: 2018-10-03
Publication date: 2020-01-31
Anticipated expiration: 2028-10-03

Abstract

The application discloses kind of equipment with liquid or gaseous precursor production nano-material includes plasma generator, reaction chamber, the cooling chamber of coaxial sealing connection in proper order, plasma generator includes radio frequency power supply, intermediate frequency power supply, plasma tube, spiral induction coil, gas distribution head the utility model has the advantages of simple structure, convenient operation, low cost, and the nano-material purity of preparation is higher, stability is good, the appearance particle diameter is even.

Description

apparatus for producing nano material from liquid or gaseous precursor

Technical Field

The present application relates to nanomaterial production, and more particularly to apparatus for producing nanomaterials from liquid or gaseous precursors.

Background

At present, the main methods for producing nano materials at home and abroad comprise two methods, namely liquid phase synthesis and gas phase synthesis. The liquid phase synthesis usually needs a proper organic intermediate, the granularity of the obtained product is well controlled, however, a large amount of organic solvent is needed, the scale-up production is not easy, and impurities are easy to introduce.

At present, the gas phase synthesis mainly comprises direct pyrolysis, laser pyrolysis, variable current laser ion beam gas phase synthesis and the like.

The product obtained by direct pyrolysis has poor performance, and the product is easy to sinter so as to lose the characteristics of the nano material. Laser and plasma assisted synthesis are two promising approaches.

The main principle of laser pyrolysis is to utilize gaseous reactants to CO₂Absorption of the laser light at a specific wavelength (10.59 microns) decomposes it in a very short time, forms tiny particles, and leaves the laser reaction zone quickly to yield a product with excellent properties. The disadvantages of laser pyrolysis are that the reaction zone is small, scale-up production is not easy, and the production cost is high. At present, laser pyrolysis is mainly used for research and development tests of novel nano materials.

The equipment relates to the technologies of laser, ion beam, vacuum and the like, and comprises a high-power laser, a high-voltage (above 80 KV) generator, an electronic lens, a high-vacuum air pumping system and other main parts and subsystems, and has the defects of complex equipment structure, high manufacturing cost, lower productivity and the like, and special nano materials, such as carbon-coated nano silicon particles, cannot be effectively produced due to the limitation of the technology.

ICP plasma nano material preparation technology is good methods for preparing nano material, ICP plasma energy density is high, reaction is simple, process flow is short, control is convenient, many beneficial attempts have been made at home and abroad, and various methods for preparing nano material by ICP plasma are provided.

Such as chinese patent 201080022699.1 filed by tacrine, canada, plasma systems, m.i. pallas j. gilvzguojia, et al; 102481536B, the manufacturing cost is high due to the complex design of the reaction equipment; the process design is unreasonable, the product synthesis yield is low, the raw material waste is caused, and the production cost is high. There are many disadvantages to the main equipment design and process design:

1. the operating frequency of a plasma torch (plasma generator) with radio frequency (2-27.12 MHz) is selected, the output power is 80-100KW, only the purchase cost of sets of radio frequency power supply equipment and matching networks thereof is needed, the radio frequency power supply needs 40-50 ten thousand dollars in 5000 dollars per KW, the price of the matching networks with the same power is about 1/4 dollars and about 10-12 ten thousand dollars of the same power, and therefore, the cost of the radio frequency power supply and the matching networks reaches 50-60 thousand dollars;

2. the reaction system is unreasonable in design:

in order to use solid, liquid and gaseous precursors in reaction systems, a plurality of heating power supplies are adopted in the systems and interfere with each other;

b, a central gas pipe of a plasma generator is adopted to send a precursor, so that in order to avoid the condition that the precursor enters a region with lower ion density on the upper part of the plasma and causes plasma to be extinguished, the central pipe extends into a high-temperature region at the central part of the induction coil, and the central pipe material is broken and damaged quickly due to high-temperature volatilization;

c, because the central tube is deep into the high-temperature region, the precursor conveyed by the central tube is decomposed and melted in the central tube, and liquid drops are formed and flow down, so that the loss of the precursor can reach 30% at most;

d, in order to avoid the contamination of the product nano powder by the reactant dropped in the central tube, a high-temperature resistant container for collecting the liquid drops is arranged below the reactor, so that the complexity of the equipment is increased;

e, the liquid precursor is fed into a high-temperature region of the center of the plasma by adopting a central tube injection method, liquid drops are rapidly gasified at high temperature, a micro-explosion phenomenon occurs in the plasma tube, foreign matter pollution is caused to the wall of the plasma tube, and the plasma tube is broken when the liquid drop is serious;

f, in order to avoid accumulation of powder generated by reaction on the wall of the reactor tube, or more than heating devices are arranged on the wall of the reactor tube, and the temperature of the whole reactor tube wall is kept above the melting points of the precursor and the product powder material, so that the powder material accumulated on the wall of the reactor tube is melted and flows downwards along the reactor tube wall, the loss of the precursor/powder material is caused, and the yield of the produced product is reduced;

g in order to prevent the reactant liquid flowing down from polluting the product powder material, a high-temperature resistant liquid collecting container is arranged below the reaction tube, so that the complexity and the manufacturing cost of the reactor are increased;

h, the temperature of the tube wall of the whole reactor is kept above the melting point of the precursor and the product powder material, the melting temperature of specific powder materials such as nickel is over 1400 ℃, and the reactor must be made of high-temperature resistant materials, so that the manufacturing cost of equipment is increased;

i, the temperature of the tube wall of the whole reactor is kept above the melting point of a precursor and a product powder material, the melting temperature of specific powder materials, such as molybdenum, tungsten, silicon nitride, silicon carbide and the like, is 2000-3500 ℃, and the melting temperature cannot be realized within the range of reasonable manufacturing cost, so that the product powder accumulates in the tube of the reactor, and the working state of the reactor can be seriously influenced;

j, the temperature of the wall of the whole reactor is kept above the melting point of the precursor and the product powder material, so that a reaction product is in a liquid drop shape in the whole reactor, the collision and fusion among a large number of liquid drops cause the particle size of powder particles to be increased, and the nano powder material with the particle size of below 30 nanometers is difficult to produce;

k keeps the temperature of the tube wall of the whole reactor above the melting point of the precursor and the product powder material, so that the retention time of various reaction products in a high-temperature area is relatively prolonged, the reverse reaction of materials is accelerated, and unnecessary or harmful side reactants are generated, for example, 2SiHCl is used as the forward reaction for preparing nano silicon particles by using trichlorosilane₃+3H₂+ high temperature 2Si +6 HCl; the reverse reaction is Si +4HCl ═ SiCl₄+2H₂Silicon tetrachloride byproducts are generated and are discharged along with tail gas; in severe cases, the silicon tetrachloride by-product produced is up to 30% or more of the reaction product, resulting in loss of precursor materials, increased difficulty and cost of tail gas treatment, and increased production cost of powder materials.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide simple structure, convenient operation, low cost, and the nano-material purity of preparation is higher, stability is good, the appearance particle diameter is even, can be applied to various equipment that are fit for being used for multiple high-end nano-material preparation extensively.

In order to achieve the above object, the present invention provides the following technical solutions.

The embodiment of the application discloses kind of equipment with liquid or gaseous precursor production nano-material includes plasma generator, reaction chamber, cooling chamber of coaxial sealing connection in proper order, plasma generator includes radio frequency power supply, intermediate frequency power supply, plasma pipe, spiral induction coil, gas distribution head, the inside plasma that is formed with of plasma takes place the inner chamber, the coaxial parcel of spiral induction coil in plasma outside of tubes wall, its upper end do radio frequency power supply incoming end, the lower extreme do intermediate frequency power supply incoming end, radio frequency power supply incoming end below is taken a percentage do radio frequency power supply, intermediate frequency power supply common ground terminal, gas distribution head seal set up in plasma top of tubes portion, the reaction chamber lateral wall is provided with at least and advances the gas ring, advance the gas ring with sealing connection between the reaction chamber lateral wall, the cooling chamber top is provided with heat exchanger, the cooling chamber includes cylindricality cooling chamber and the toper cooling chamber that coaxial sealing set up, cylindricality cooling chamber sealing connection in reaction chamber tail end.

Preferably, in the above apparatus for producing nanomaterials from liquid or gaseous precursors, the apparatus further comprises a high-voltage ignition electrode introduced into the plasma generation cavity from the gas distribution head.

Preferably, in the above apparatus for producing nanomaterial from a liquid or gaseous precursor, the plasma tube has an inner diameter of 30 to 160 mm, a height of 200 to 400 mm, and a wall thickness of 3 to 5 mm.

Preferably, in the above apparatus for producing nanomaterial with liquid or gaseous precursor, the gas distribution head is provided with a central gas pipe at the axial center in a sealing manner, the central gas pipe being communicated with the plasma generation cavity.

Preferably, in foretell equipment of using liquid or gaseous precursor to produce nano-material, the intercommunication has been seted up to the gas distribution head the rotatory gas intake pipe of inner chamber is taken place to plasma, rotatory gas intake pipe communicate in the entry that inner chamber was taken place to plasma is located inner chamber top side is taken place to plasma, gas distribution head coaxial coupling is provided with the cyclone stand pipe, the cyclone stand pipe is located inner chamber top is taken place to plasma, the interior pure argon gas that lets in of rotatory gas intake pipe.

Preferably, in the above apparatus for producing a nanomaterial with a liquid or gaseous precursor, a cooling pipe is coaxially disposed between the spiral induction coil and the plasma tube, a cooling liquid flows between an inner wall of the cooling pipe and an outer wall of the plasma tube, an air inlet flange is coaxially and hermetically communicated with a bottom of the plasma tube, and an air inlet cavity communicated with an inner cavity of the air inlet flange is formed in a side surface of the air inlet flange.

Preferably, in the above apparatus for producing nanomaterial from liquid or gaseous precursor, the gas inlet ring above introduces a liquid precursor, which is a compound containing an element required by nanomaterial, into the reaction chamber by hydrogen, nitrogen, or argon.

Preferably, in the above apparatus for producing nanomaterial from a liquid or gaseous precursor, the gas inlet ring below is fed with a cooling gas.

The utility model has the advantages of simple structure, convenient operation, low cost, and the nano-material purity of preparation is higher, stability is good, the appearance particle diameter is even, can be general in various preparation that are fit for being used for multiple high-end nano-material.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only the embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of an apparatus for producing nanomaterials from liquid or gaseous precursors according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a plasma tube according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a high-power composite frequency ICP plasma generator according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an ICP plasma gas phase reactor for producing nanomaterials from liquid or gaseous precursors according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an ICP plasma gas-phase cooler for producing nanomaterials from liquid or gaseous precursors according to an embodiment of the present invention;

fig. 6 is a schematic structural view of a bubbler according to an embodiment of the present invention;

FIG. 7 is a top view of an air inlet ring according to an embodiment of the present invention;

FIG. 8 is a top view of a heat exchanger according to an embodiment of the present invention;

FIG. 9 shows an axial distribution of gas temperature in the reaction chamber according to an embodiment of the present invention.

Detailed Description

The technical solution in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments, not all embodiments, of .

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present invention.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" shall be construed , for example, they may be fixedly connected, detachably connected, or physically connected, mechanically connected, electrically connected, directly connected, indirectly connected through an intermediate medium, and communicating between two elements.

Referring to fig. 1, the apparatus for producing nanomaterial from liquid or gaseous precursor includes a plasma generator 100, a reaction chamber 200, and a cooling chamber 300, which are coaxially and hermetically connected.

As shown in fig. 1 to 3, the high power composite frequency ICP plasma generator 100 includes:

a radio frequency power supply 110 with the frequency of 3-27.12MHz and the power of 1-10 KW;

a medium frequency power supply 120 with the frequency of 50-1000KHz and the power of 10-200 KW;

a plasma tube 130 having a plasma generation chamber 131 formed therein;

the spiral induction coil 140 is coaxially wrapped on the outer wall of the plasma tube 130, the upper end of the spiral induction coil is a radio frequency power supply access end 141, the lower end of the spiral induction coil is an intermediate frequency power supply access end 142, and a tap below the radio frequency power supply access end 141 is a radio frequency power supply and intermediate frequency power supply common grounding end 143;

and the gas distribution head 150 is hermetically arranged at the top of the plasma tube 130. Made of quartz, ceramic or other insulating material, for supplying the plasma-generating chamber with the gas required for the plasma.

Taking a 30KW composite frequency induction power supply ICP plasma generator as an example, a 2500W 12.56 MHz water-cooling radio frequency power supply is selected as a radio frequency power supply; the radio frequency matching network selects 3000 Wpi type water-cooling matching network, the power source of the intermediate frequency power supply selects 15KW and 50 KHz water-cooling intermediate frequency power supply, and of course, the power sources of other power and frequency in the selected range can also be realized, and all the power sources belong to the range of the application.

The plasma generator is fixedly connected with the upper connecting plate, the screws and the like through connecting rods to form whole bodies.

, a high voltage ignition electrode (not shown) is introduced into the plasma generation chamber 131 from the gas distribution head 150.

The high-voltage power supply 500 of the high-voltage ignition electrode adopts a 10KV and 20 mA alternating-current high-voltage transformer.

, the plasma tube 130 is made of kinds of silicon nitride, boron nitride, aluminum nitride ceramics, the inner diameter of the plasma tube 130 is 30 to 160 mm, the height is 200 to 400 mm, and the wall thickness is 3 to 5 mm.

In the technical scheme, the material mixed according to various proportions is added with various additives and filling materials to prepare the material with the characteristics of high thermal conductivity, high resistivity, low expansion rate and thermal shock resistance. A plasma is generated in the plasma tube.

, wrapping a copper pipe with a diameter of 8-20mm by a ceramic material or a heat-insulating fiber material 144 to form a pipe shape for the spiral induction coil 140, wherein the number of turns of the spiral induction coil 140 is 6-7, the distance between two adjacent turns is 5-10mm, and the position of the common ground terminal 143 is a tap position 1-2 turns below the radio frequency power supply access terminal 141.

The spiral induction ring is sleeved on the cooling pipe, is close to the gas distribution head, and is 10-100 mm away from the gas distribution head.

, a cooling tube 160 is coaxially disposed between the spiral induction coil 140 and the plasma tube 130, and a cooling liquid flows between the inner wall of the cooling tube 160 and the outer wall of the plasma tube 130.

The cooling tube is made of quartz or ceramic material, and has an inner diameter of 50-200 mm, a length of 250-450 mm and a wall thickness of 3-5 mm.

, a central gas pipe 151 communicated with the plasma generating cavity 131 is hermetically arranged at the axis of the gas distributing head 150, and pure argon or the mixed gas of the pure argon, nitrogen and hydrogen is introduced into the central gas pipe 151.

In this embodiment, the central gas tube is made of quartz, ceramic or other insulating material, has an inner diameter of 8 to 16 mm, a wall thickness of 1 to 2 mm and a length of 150 to 200 mm, and is used to inject or more process gases.

, the gas distribution head 150 is provided with or more rotary gas inlet pipes 152 communicated with the plasma generation cavity 131, the rotary gas inlet pipes 152 are communicated with the inlet of the plasma generation cavity 131 and positioned on the side surface of the top of the plasma generation cavity 131, the gas distribution head 150 is coaxially connected with a cyclone guide pipe 153, the cyclone guide pipe 153 is positioned on the top of the plasma generation cavity 131, and pure argon is introduced into the rotary gas inlet pipes 152.

The gas inlet tube is tangent to the chamber and is used for injecting argon or other gas required by plasma, the cyclone guide tube is made of quartz, ceramic or other insulating materials, has an inner diameter of 35-140 mm, a length of 50-100 mm and a wall thickness of 2-3 mm, and the gas entering from the gas inlet tube flows spirally in the tube to the other end under the guidance of the cyclone guide tube.

, a water outlet flange 170 is hermetically arranged between the gas distribution header 150 and the cooling pipe 160, a water outlet 171 is arranged at the top of the water outlet flange 170, the cooling liquid flows out of the water outlet 171, and a sealing flange 172 is arranged at the bottom of the water outlet flange 170.

In the technical scheme, the water outlet flange and the sealing flange are made of quartz or ceramics or metal, are fixed by bolts and are sealed by sealing rings/sealing gaskets made of polytetrafluoroethylene, rubber or other flexible materials.

, the bottom of the plasma tube 130 is coaxially and hermetically communicated with an air inlet flange 180, the side of the air inlet flange 180 is provided with an air inlet cavity 181 communicated with the inner cavity of the air inlet flange 180, and nitrogen or hydrogen or other process gases are introduced into the air inlet cavity 181.

, a water ring flange 190 is coaxially and hermetically arranged between the air inlet flange 180 and the cooling pipe 160, an annular cavity 191 communicated with the inside of the cooling pipe 160 is formed in the inner wall of the water ring flange 190, a water inlet flange 182 is coaxially and hermetically arranged at the bottom of the air inlet flange 180, a water inlet 183 is formed in the side of a 182 of the water inlet flange 182, a liquid inlet channel 184 communicated with the annular cavity 191 is sequentially formed in the water inlet flange 182 and the air inlet flange 180, and cooling liquid flows into the annular cavity 191 after flowing into the liquid inlet channel 184 from the water inlet 183 and then flows into the inside of the cooling pipe 160.

In the technical scheme, the water ring flange, the air inlet flange and the water inlet flange are respectively composed of quartz or ceramics or metal, and the joints are bonded and sealed by high-temperature adhesives.

, the rf power source 110 is connected to the rf matching network 111 through a coaxial cable, the rf matching network 111 connects the rf power to the rf power source input 141 through the coaxial cable, and the if power source 120 is connected to the if power source input 142 through a water-cooled cable.

The plasma is excited by high-power medium-frequency alternating electromagnetic field to generate high-temperature plasma with power of tens to hundreds of kilowatts.

After working gas enters a plasma generating cavity and airflow stabilization time delay of 1-2 minutes is carried out, a high-voltage power supply is started, a radio-frequency power supply and a medium-frequency power supply are started, the forward radio-frequency power is 1500 watts preferably, the reverse radio-frequency power is lower than 50 watts, the initial medium-frequency power is adjusted to 10-15KW, after stabilization of 1-2 minutes, the output power of the medium-frequency power supply is adjusted to 30KW at the rate of 2-5KW per minute, stable power supply and gas input are maintained, good cooling water supply is achieved, the plasma generator can continuously and stably work for tens of hours to days.

Referring to fig. 1 and 4-7, an ICP plasma gas-phase reactor for producing a nanomaterial by using a liquid or gaseous precursor includes a reaction chamber 200, two ends of the reaction chamber 200 are coaxially and hermetically connected to a plasma generator 100 and a cooling chamber 300, a sidewall of the reaction chamber 200 is at least provided with air inlet rings 210, the air inlet rings 210 are hermetically connected to a sidewall of the reaction chamber 200, an annular static pressure chamber 211 is formed inside the air inlet rings 210, a plurality of cyclone nozzles 212 communicated with the annular static pressure chamber 211 are formed on a sidewall of the reaction chamber 200, the plurality of cyclone nozzles 212 are sequentially arranged along a circumferential direction of the reaction chamber 200, a reaction chamber cleaning ring 220 is coaxially arranged inside the cooling chamber 300, a diameter of the reaction chamber cleaning ring 220 is slightly smaller than a diameter of the reaction chamber 200, and the reaction chamber cleaning ring 220 cleans an inner wall of the reaction chamber 200.

The upper gas inlet ring 210 introduces a liquid precursor 244 into the reaction chamber 200 through hydrogen or nitrogen or argon, the liquid precursor 244 being a compound containing elements required by the nanomaterial. The lower gas inlet ring 210 is filled with cooling gas, which is hydrogen gas, argon gas, nitrogen gas, helium gas, or a mixture thereof. Different cooling gases can be selected for different types of precursors, and the temperature of the reaction cavity is cooled while the occurrence of reverse reaction is inhibited or the degree of the occurrence of reverse reaction is reduced.

The gas enters the reaction cavity in a rotating mode, and the reaction time is prolonged.

, an air inlet nozzle 213 communicated with the annular static pressure cavity 211 is arranged at the side of the air inlet ring 210 , and the extension line of the air rotary nozzle 212 does not intersect with the axial lead of the reaction cavity 200.

, the sidewall of the reaction chamber 200 is a double-layer tube wall 230, a double-layer tube wall inlet 231 and a double-layer tube wall outlet 232 are formed at the bottom and the top side of the double-layer tube wall 230, respectively, and cooling liquid flows between the double-layer tube walls 230.

, the top and bottom of the reaction chamber 200 are hermetically connected to the plasma generator 100 and the cooling chamber 300 through a connecting flange 250, and the th double-layer tube wall inlet 231 and the th double-layer tube wall outlet 232 are respectively disposed on the sidewall of the connecting flange 250.

, the side wall of the reaction chamber 200 is provided with at least two thermocouples 400 from top to bottom for monitoring the temperature inside the reaction chamber 200 at the position.

Used for temperature measurement and regulation in the reaction chamber.

, the reaction chamber cleaning ring 220 is driven by a drive shaft 221 coaxially disposed at .

, the apparatus further comprises a bubbler 240, which comprises a bottle , a bottle inlet pipe 242 and a bottle outlet pipe 243, wherein the bottle 241 is hermetically connected to the bottle 241, the liquid precursor 244 is disposed in the bottle 241, the bottle inlet pipe 242 extends to the liquid precursor 244, and the bottle outlet pipe 243 is hermetically connected to the gas inlet nozzle 213. the apparatus further comprises a heating evaporator (not shown), which heats the liquid precursor 244 to generate vapor and then leads the vapor to the gas inlet nozzle 213.

The liquid precursor can be fed into the reaction chamber through a gas inlet ring by using a bubbler to carry volatilized vapor of liquid precursor liquid, including but not limited to hydrogen, nitrogen and argon;

the liquid precursor can also be fed into the reaction chamber through the gas inlet ring by, but not limited to, heating the evaporator to boil the liquid precursor to generate vapor.

The liquid precursor is a compound containing elements required by the nano material, has a low boiling point, can be carried by gas bubbling or heated and evaporated to form steam , can be used for liquid compounds of CVD, MOCVD and the like, and can be used as a precursor of the ICP plasma gas phase reactor.

, a liner tube (not shown) is inserted into the reaction chamber 200.

In the technical scheme, the lining pipe can be inserted for preparing different nano-powder; the lining pipe of the reaction cavity can be made of metal, quartz and ceramic materials.

The reaction cavity cleaning ring is used for cleaning powder accumulated on the inner wall of the reaction cavity and the surface of the heat exchanger, the air inlet ring is used for providing a precursor and reaction gas required by reaction to the reaction cavity, the structure is simple, the operation is convenient, the cost is low, the prepared nano material is high in purity, good in stability and uniform in shape and particle size, and can be applied to preparation of various high-end nano materials in ₄、Si₂H₆、Si₃H₈Etc.; chlorosilane, which may be SiH₂Cl₂、SiHCl₃、SiCl₄、Si₂Cl₆And the like.

Referring to fig. 1, 5 and 8, an ICP plasma gas cooler for producing a nanomaterial by using a liquid or gaseous precursor includes a cooling chamber 300, the cooling chamber 300 is coaxially and hermetically connected to a rear end of a reaction chamber 200, a heat exchanger 310 is disposed at a top of the cooling chamber 300, the heat exchanger 310 includes a plurality of cooling water chambers 311 arranged in a ring shape and a cooling liquid pipeline 312 communicated with the plurality of cooling water chambers 311, the cooling chamber 300 includes a cylindrical cooling chamber 320 and a conical cooling chamber 330 coaxially and hermetically arranged, the cylindrical cooling chamber 320 is hermetically connected to a rear end of the reaction chamber 200, a cooling chamber cleaning ring 321 is disposed in the cylindrical cooling chamber 320, a diameter of the cooling chamber cleaning ring 321 is slightly smaller than a diameter of the cylindrical cooling chamber 320, and the cooling chamber cleaning ring 321 cleans an inner wall of the cylindrical cooling chamber 320.

, the cooling chamber cleaning rings 321 are disposed opposite to each other, and the cooling chamber cleaning rings 321 are driven by two opposite telescopic rods 322, and the telescopic rods 322 are sealed to penetrate through the side wall of the conical cooling chamber 330.

, the cooling water cavity 311 has a trapezoidal cross section with the shorter side of the trapezoid being close to the axis of the cooling cavity 300.

, a moving space 313 for moving the reaction chamber cleaning ring 220 is formed among the plurality of cooling water chambers 311 in a ring shape.

, the side wall of the cooling cavity 300 is a second double-layer tube wall 340, a second double-layer tube wall inlet 341 and a second double-layer tube wall outlet 342 are formed at the bottom and the top side of the second double-layer tube wall 340, respectively, and cooling liquid flows between the second double-layer tube wall 340.

, the coolant line 312 communicates with the interior of the second double walled tube 340.

, the top and bottom of the cooling chamber 300 are hermetically connected to the reaction chamber 200 and the powder collection system (not shown) via a second connecting flange 350, and the second dual-wall inlet 341 and the second dual-wall outlet 342 are disposed on the side wall of the second connecting flange 350.

, the side wall of the cooling chamber 300 is provided with at least thermocouples 400 from top to bottom for monitoring the temperature inside the cooling chamber 300 at the position.

For temperature measurement and regulation in the cooling chamber.

The cooling cavity cleaning ring is used for cleaning powder accumulated on the inner wall of the cylindrical cooling cavity, the cylindrical structure is simple, the operation is convenient, the cost is low, the prepared nano material has high purity, good stability and uniform morphology and particle size, and can be widely applied to the preparation of various high-end nano materials in .

The method for preparing the nano-material of the present invention will be described below by taking the preparation of nano-silicon powder as an example.

Introducing argon, or hydrogen, or nitrogen, or a mixed gas of argon and hydrogen, nitrogen and other gases in any proportion into the central gas pipe; introducing argon into the rotary gas inlet pipe, generating high-power plasma in the plasma generating cavity under the excitation of an alternating electric field with composite frequency, and discharging high-temperature gas ionized by the plasma heating into the reaction cavity;

introducing argon, or hydrogen, or nitrogen, or mixed gas of argon and hydrogen, nitrogen and other gases in any proportion into the gas inlet flange, adjusting the temperature of the gas entering the reaction cavity to be 200-300 ℃ higher than the critical reaction temperature of the selected precursor, and monitoring by using a thermocouple;

introducing diluted silicon precursor gas into a reaction cavity through an upper gas inlet ring, monitoring the gas temperature in the reaction cavity through a thermocouple, wherein the temperature is higher than the critical reaction temperature of the selected precursor by 100-200 ℃, introducing argon, hydrogen, nitrogen or a mixed gas of argon, hydrogen, nitrogen and other gases in any proportion into the lower gas inlet rings, monitoring the gas temperature in the reaction cavity through the thermocouple, adjusting the temperature to be higher than the critical reaction temperature of the selected precursor by 50-100 ℃ through adjusting the gas flow of the gas inlet rings, continuing introducing argon, hydrogen, nitrogen or a mixed gas of argon, hydrogen, nitrogen and other gases in any proportion into the lower gas inlet rings, monitoring the gas temperature at the inlet of the cooling cavity through the thermocouple, and adjusting the temperature to be lower than the critical reaction temperature of the prepared nano powder and reaction byproducts by 100-200 ℃.

The axial distribution of the gas temperature in the reaction cavity is shown in figure 9, wherein letters respectively show that A is the temperature of the connection part of the ion generator and the reaction cavity, B-F are the temperature of the uppermost gas inlet ring, the middle gas inlet ring, the lowermost gas inlet ring and the temperature among the uppermost gas inlet ring, the middle gas inlet ring and the lowermost gas inlet ring in sequence, G is the temperature of the top of the cooling cavity, the axial distribution of the gas temperature is divided into 5 regions, more than A is a high-temperature plasma region, A-B is a temperature adjusting region, B-D is a main reaction region, in the temperature region, the precursor completes the cracking and nucleation reaction, D-E is a particle agglomeration region, particles formed by cracking and nucleation of the precursor are agglomerated into nanoparticles in the temperature region, F-G is a reverse reaction inhibiting region, and the temperature of a reaction product is rapidly reduced to be lower than the critical temperature of the side reaction in the region;

the nano particles synthesized by the reaction and the reaction tail gas are discharged into a cooling cavity from the bottom of the reaction cavity, are cooled, are sent into a nano powder collecting system to be collected, and are discharged into a tail gas treatment system to be treated and then are discharged.

The ICP plasma generator adopts a composite frequency high-power ICP plasma generator, the purchase cost is 10 to 15 percent of that of a radio frequency ICP plasma generator with equivalent power, and the manufacturing cost of the equipment is greatly reduced; the reasonable design of the process and the structure improves the utilization rate of the precursor material, reduces the manufacturing cost of equipment and the production cost of the nano material, and can produce the nano powder material with the grain diameter of less than 30 nanometers.

It should be noted that, in this document, relational terms such as , second and the like are only used to distinguish entities or operations from another entities or operations, and no necessarily requires or implies that any such actual relationship or order exists between the entities or operations.

The foregoing is directed to embodiments of the present application and it is noted that numerous modifications and adaptations may be made by those skilled in the art without departing from the principles of the present application and are intended to be within the scope of the present application.

Claims

The utility model provides an kind of equipment with liquid or gaseous precursor production nano-material, its characterized in that includes plasma generator, reaction chamber, the cooling chamber of coaxial sealing connection in proper order, plasma generator includes radio frequency power supply, intermediate frequency power supply, plasma pipe, spiral induction coil, gas distribution head, the plasma inside is formed with plasma and takes place the inner chamber, the coaxial parcel of spiral induction coil in plasma outside of tubes wall, its upper end do radio frequency power supply incoming end, the lower extreme do intermediate frequency power supply incoming end, radio frequency power supply incoming end below is taken a percentage do radio frequency power supply, intermediate frequency power supply common ground terminal, gas distribution head seal set up in plasma top of tubes portion, the reaction chamber lateral wall is provided with at least and advances the gas ring, advance the gas ring with sealing connection between the reaction chamber lateral wall, the cooling chamber top is provided with heat exchanger, the cooling chamber includes cylindricality cooling chamber and the toper cooling chamber that coaxial sealing set up, cylindricality cooling chamber sealing connection in reaction chamber tail end.
2. The apparatus of claim 1, further comprising a high voltage ignition electrode introduced into the plasma generation chamber from the gas distribution header.
3. The apparatus for producing nano-materials from liquid or gaseous precursors as claimed in claim 1, wherein the inner diameter of the plasma tube is 30 to 160 mm, the height is 200 to 400 mm, and the wall thickness is 3 to 5 mm.
4. The apparatus for producing nano-materials from liquid or gaseous precursors according to claim 1, wherein a central gas pipe communicating with the plasma generation cavity is hermetically disposed at the axis of the gas distribution head.
5. The apparatus of claim 1, wherein the gas distribution head is provided with a rotary gas inlet tube communicating with the plasma generation cavity, the rotary gas inlet tube is communicated with an inlet of the plasma generation cavity and is located at a side surface of a top of the plasma generation cavity, the gas distribution head is coaxially connected to a cyclone guide tube, the cyclone guide tube is located at the top of the plasma generation cavity, and pure argon gas is introduced into the rotary gas inlet tube.
6. The apparatus for producing nanomaterial according to claim 1, wherein a cooling pipe is coaxially disposed between the spiral induction coil and the plasma tube, a cooling liquid flows between an inner wall of the cooling pipe and an outer wall of the plasma tube, a gas inlet flange is coaxially and hermetically communicated with a bottom of the plasma tube, and a gas inlet cavity communicated with an inner cavity of the gas inlet flange is opened on a side surface of the gas inlet flange.
7. The apparatus for producing nanomaterials with liquid or gaseous precursors thereof according to claim 1, wherein the upper gas inlet ring introduces a liquid precursor into the reaction chamber by means of hydrogen or nitrogen or argon, the liquid precursor being a compound containing elements required by the nanomaterials.
8. The apparatus for producing nanomaterials from liquid or gaseous precursors claim 1, wherein the lower gas inlet ring is fed with a cooling gas.