Integrated burner system for efficiently preparing carbon nanotubes

Abstract

The invention relates to the technical field of carbon nanotube preparation combustion equipment, in particular to an integrated combustor system for efficiently preparing carbon nanotubes, which comprises a primary combustor, a pre-oxidation chamber and a secondary combustor, the upper part of the primary combustor is communicated with the pre-oxidation chamber, and the upper part of the pre-oxidation chamber is communicated with the secondary combustor; a collecting device is arranged above the secondary combustor; the pre-oxidation chamber is composed of a lower chamber, a fan and an upper chamber, the lower chamber is arranged to be of a convergent-divergent spray pipe type structure, the upper chamber is arranged to be of a necking structure, the system adopts an innovative integrated structural design, soot is generated through combustion of the first-stage combustor, and the soot has the enough high temperature after being combusted through the second-stage combustor, so that the soot can be combusted through the second-stage combustor; a synergistic effect is generated after contact with catalyst particles, and the carbon source is catalytically decomposed on the surface of the soot to generate the carbon nanotubes, so that the yield of the carbon nanotubes is improved.

Description

Technical Field

[0001] The invention relates to the technical field of carbon nanotube standby combustion equipment, and in particular to an integrated burner system for efficiently preparing carbon nanotubes. Background Art

[0002] Carbon nanotubes are a cutting-edge nanomaterial that has a wide range of applications in hydrogen storage materials, lithium-ion batteries and other fields. As a method of producing carbon nanotubes, the flame method is characterized by high energy efficiency, low cost and easy operation. The flame method can provide both the carbon source and the reaction temperature required for carbon nanotubes, and has the potential to produce carbon nanotubes on a large scale.

[0003] The flame method for preparing carbon nanotubes involves the combustion of fuel, which provides a carbon source and the required reaction temperature for the generation of carbon nanotubes. The carbon source is then catalytically decomposed on the surface of the catalyst particles to form carbon and diffuses through the surface or body, eventually nucleating and growing to form carbon nanotubes. At present, the combustion method for preparing carbon nanotubes by the flame method is mainly focused on diffusion combustion (such as a burner with a controllable flame and symmetrical distribution and a method for synthesizing carbon nanotubes with patent number: CN202210018581.6 and a manufacturing device and production method of a carbon black-carbon nanotube composite material with application number: CN202111010781.9). In this process, the carbon source generated by combustion is captured by the substrate to catalyze the generation of carbon nanotubes. The biggest problem with this method is that the carbon source has a low carbon content, resulting in low efficiency in preparing carbon nanotubes; and when a carbon source with a high carbon content, such as ethylene and acetylene, a large amount of carbon smoke is generated and quickly adheres to the substrate, covering the catalyst and causing the catalyst to be inactivated. Therefore, it is extremely urgent to design and provide an integrated burner system that can efficiently prepare carbon nanotubes. Summary of the invention

[0004] The purpose of the present application is to provide an integrated burner system for efficiently preparing carbon nanotubes. The system adopts an innovative integrated structural design, in which the first-stage burner burns to produce carbon soot. After burning in the second-stage burner, the carbon soot has a sufficiently high temperature and produces a synergistic effect after contacting with catalyst particles. The carbon source is catalytically decomposed on the surface of the carbon soot to generate carbon nanotubes, thereby increasing the yield of carbon nanotubes.

[0005] The technical solution adopted by this application to solve the above technical problems is: An integrated burner system for efficiently preparing carbon nanotubes, comprising a primary burner, a pre-oxidation chamber, and a secondary burner; the upper portion of the primary burner is connected to the pre-oxidation chamber, and the upper portion of the pre-oxidation chamber is connected to the secondary burner; a collecting device is arranged above the secondary burner; The pre-oxidation chamber consists of a lower chamber, a fan and an upper chamber. The lower chamber is arranged as a convergent-convergent nozzle structure, and the upper chamber is arranged as a constricted structure. A cooling water channel is arranged on the periphery of the inner wall of the pre-oxidation chamber. A water inlet a is arranged at the connection between the cooling water channel and the top of the upper chamber, a water outlet b is arranged at the connection between the cooling water channel and the bottom of the lower chamber, and an ignition electrode is arranged above the water outlet b.

[0006] The lower chamber includes an inlet section, a contraction section, a throat, a diffusion section, and an outlet section; the first-stage burner is connected to the inlet section; the contraction section is connected to the upper part of the inlet section; the throat is connected to the upper part of the contraction section, and the diffusion section is connected to the upper part of the throat; the outlet section is connected to the upper part of the diffusion section, and the inlet section, contraction section, throat, diffusion section and outlet section constitute a convergent-divergent nozzle structure, which can prevent the carbon smoke from falling due to insufficient power when it rises to a certain height, thereby ensuring that the carbon smoke has sufficient buoyancy.

[0007] Furthermore, the contraction section and the diffusion section are arranged obliquely along the length direction of the vertical throat.

[0008] Furthermore, the inclination angle of the contraction section is 20°, and the inclination angle of the diffusion section is 15°.

[0009] Furthermore, air nozzles and fuel nozzles a are arranged on both sides of the diffuser section, respectively, and the air nozzles and fuel nozzles a are arranged perpendicular to the diffuser section.

[0010] Furthermore, the fan includes a connection port a and a connection port b, the connection port a is connected to the lower chamber outlet section; the connection port b is connected to the upper chamber; a wind shield is arranged at the lower end of the connection port a, and the wind shield can prevent the fan suction from affecting the flame of the first-stage burner, and the wind shield adopts a hexagonal hollow array structure to reduce the throttling loss of the fan during the suction process.

[0011] Furthermore, a water inlet b is arranged below the connection between the connection port a and the lower chamber; a water outlet a is arranged above the connection between the connection port b and the upper chamber; and the water outlet a and the water inlet b are connected by a cooling water pipe.

[0012] Furthermore, a fuel nozzle b is arranged at the end of the upper chamber contraction structure; the fuel nozzle b is connected to the secondary burner by a stainless steel pipeline.

[0013] Furthermore, a collecting device is arranged above the secondary burner, and the collecting device includes a lifting mechanism and a base plate, and the base plate is placed on the lifting mechanism.

[0014] The present invention also discloses a method for using the above-mentioned integrated burner system for efficiently preparing carbon nanotubes, and the specific steps are as follows: Step 1: Open the constant temperature water tank I and the constant temperature water tank II to keep the primary burner and the secondary burner at a constant temperature; introduce cooling water into the water inlet a; Step 2: Open the intake valve I, intake valve II, intake valve III and flowmeter I, flowmeter II, flowmeter III, and use the ignition electrode to ignite the first-stage burner to generate carbon smoke; Step 3: Open the air inlet valve IV, the air inlet valve V and the flowmeter IV, the flowmeter V, and introduce air and fuel into the air nozzle and the fuel nozzle of the diffusion section of the lower chamber of the pre-oxidation chamber respectively, and fully mix with the soot to form a combustible mixed gas; Step 4: Control the motor speed through the fan controller, so that the combustible mixed gas enters the secondary burner, and turn on the flow meter VI at the same time; Step 5: Ignite the secondary burner, the soot is captured by the substrate, and the carbon source is catalytically decomposed on the surface of the soot to generate carbon nanotubes.

[0015] The beneficial effects of the present invention are as follows: 1. The overall structural design of the integrated burner system of the present invention is scientific and adopts an integrated design. By controlling the switches of the relevant air intake valve, flow meter and fan controller, efficient preparation of carbon nanotubes can be achieved, and the operation is simple; the lower chamber of the pre-oxidation chamber of the present invention is designed as a zoom nozzle structure to realize the automatic floating of carbon smoke, making it easier to reach the secondary burner; 2. The arrangement of the fan in the integrated burner system of the present invention provides the pressure of the pre-oxidation chamber, so that the soot in the upper chamber of the pre-oxidation chamber has sufficient pressure to be sprayed into the secondary burner. At the same time, the fan speed can be changed by operating the controller of the fan, thereby achieving the effect of adjusting the flow rate; 3. The arrangement of the windshield in the integrated burner system of the present invention prevents the air intake of the fan from affecting the flame of the first-stage burner; it is designed as a hexagonal hollow array structure, which can reduce the throttling loss of the fan during the air intake process; at the same time, the collecting device in the present invention is designed as a lifting mechanism, which can prepare carbon nanotubes in different reaction temperature zones by adjusting the height. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention in Example 1; Figure 2 for Figure 1 along Figure 1AA overall structure diagram (excluding the collection device); Figure 3 It is a structural schematic diagram of the fan in the present invention; Figure 4 It is a structural schematic diagram of the windshield in the present invention; Figure 5 It is a schematic diagram of the structure of the collecting device in the present invention; The numbers in the figure are: 1-first-stage burner, 2-pre-oxidation chamber, 21-lower chamber, 22-blower, 23-upper chamber, 24-cooling water channel, 3-second-stage burner, 4-collection device, 41-lifting mechanism, 42-base plate; 21-lower chamber of pre-oxidation chamber, 211-ignition electrode, 212-inlet section, 213-contraction section, 214-throat, 215-diffusion section, 216-exit section, 217-air nozzle , 218-fuel nozzle a, 219-wind shield; 22-fan includes 221-connection port a, 222-controller, 223-motor, 224-connection port b; 23-pre-oxidation chamber, 231-fuel nozzle b; 24-cooling water circuit, 241-water inlet a, 242-water outlet a, 243-water inlet b, 244-water outlet b; 4-collecting device includes 41-lifting mechanism and 42-base plate. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application. Specific embodiment 1: The present invention provides an embodiment: as shown in the specification of the present invention Figure 1 As shown, in order to solve the problem of low carbon content of carbon source in the existing flame method for preparing carbon nanotubes, resulting in low efficiency in preparing carbon nanotubes, this embodiment provides an integrated burner system for efficiently preparing carbon nanotubes, which includes a primary burner 1, a pre-oxidation chamber 2, and a secondary burner 3; the pre-oxidation chamber 2 is composed of a lower chamber 21, a fan 22 and an upper chamber 23, the lower chamber 21 is arranged as a convergent nozzle structure, the upper chamber 23 is arranged as a constriction structure, a cooling water channel 24 is arranged on the periphery of the inner wall of the pre-oxidation chamber 2, a water inlet a241 is arranged at the connection between the cooling water channel 24 and the top of the upper chamber 23, a water outlet b244 is arranged at the connection between the cooling water channel 24 and the bottom of the lower chamber 21, and an ignition electrode 211 is arranged above the water outlet b244; the burner used in the system of the present invention contains a porous sintered plate structure, when the fuel and air pass through the porous sintered plate, they are straightened, so that the combustion is more stable.

[0020] Specifically, the pre-oxidation chamber 2 is composed of a lower chamber 21, a fan 22 and an upper chamber 23, wherein the lower chamber 21 includes an inlet section 212, a contraction section 213, a throat 214, a diffusion section 215 and an outlet section 216; the first-stage burner 1 is connected to the inlet section 212; the contraction section 213 is connected and arranged at the upper part of the inlet section 212; the throat 214 is connected and arranged at the upper part of the contraction section 213, and the diffusion section 215 is connected and arranged at the upper part of the throat 214; the outlet section 216 is connected and arranged at the upper part of the diffusion section 215, and the inlet section 212, the contraction section 213, the throat 214, the diffusion section 215 and the outlet section 216 constitute a convergent-divergent nozzle structure, which can prevent the soot from falling due to insufficient power when it rises to a certain height, thereby ensuring that the soot has sufficient buoyancy.

[0021] More specifically, the air nozzle 217 and the fuel nozzle a218 are arranged perpendicular to the diffusion section 215. This arrangement can not only fully mix the air, fuel and soot, but also further promote the soot to float upward.

[0022] Specifically, the fan 22 includes a connection port a221 and a connection port b222, and a wind shield 219 is arranged at the lower end of the connection port a221; the arrangement of the wind shield 219 can prevent the fan suction from affecting the flame of the first-stage burner 1; at the same time, the wind shield 219 is designed as a hexagonal hollow array structure, which can reduce the throttling loss of the fan 22 during the suction process.

[0023] More specifically, the connection port a221 is connected to the lower chamber outlet section 216, and a water inlet b243 is arranged below the connection between the connection port a221 and the lower chamber 21; the connection port b222 is connected to the upper chamber 23, and a water outlet a242 is arranged above the connection between the connection port b222 and the upper chamber 23, and the water outlet a242 and the water inlet b243 are connected by a cooling water pipe. This connection allows the cooling water paths of the upper chamber 23 and the lower chamber 21 to communicate with each other.

[0024] Further, as the instruction manual Figure 1 As shown, a fuel nozzle b231 is arranged at the end of the tapered structure of the upper chamber 23, and the fuel nozzle b231 is connected to the secondary burner 3 by a stainless steel pipeline; the design of the tapered structure of the upper chamber 23 allows the upper chamber 23 to be connected to the secondary burner 3 by a stainless steel pipeline.

[0025] Further, as the instruction manual Figure 1 As shown, a collecting device 4 is arranged above the secondary burner 3 , and the collecting device 4 includes a lifting mechanism 41 and a base plate 42 . The lifting mechanism 41 is a retractable lifting structure, and the base plate 42 is placed on the lifting mechanism 41 .

[0026] The method for using the integrated burner system for efficiently preparing carbon nanotubes of the present invention comprises the following specific steps: Step 1: Open the constant temperature water tank I and the constant temperature water tank II to keep the primary burner 1 and the secondary burner 3 at a constant temperature; introduce cooling water into the water inlet a; Step 2: Open the air intake valves I, II, III and flowmeters I, II and III, and use the ignition electrode 211 to ignite the primary burner 1 to generate carbon smoke; Step 3: Open the air inlet valve IV, the air inlet valve V and the flowmeter IV, the flowmeter V, and introduce air and fuel into the air nozzle 217 and the fuel nozzle a218 of the diffusion section 215 of the lower chamber 21 of the pre-oxidation chamber, respectively, and fully mix with the soot to form a combustible mixed gas; Step 4: Control the motor speed through the fan controller, so that the combustible mixed gas is passed into the secondary burner 3, and the flow meter VI is turned on at the same time; Step 5: Ignite the secondary burner 3, the soot is captured by the substrate 42, and the carbon source is catalytically decomposed on its surface to generate carbon nanotubes.

[0027] In summary, compared with the carbon nanotube standby combustion system, the integrated burner system for efficiently preparing carbon nanotubes of the present invention adopts an innovative integrated structural design. By controlling the switches of the relevant air intake valves, flow meters and fan controllers, efficient preparation of carbon nanotubes can be achieved, and the operation is simple; the lower chamber 21 of the pre-oxidation chamber of the present invention is designed as a zoom nozzle structure to realize the automatic buoyancy of carbon soot, making it easier to reach the secondary burner; the arrangement of the fan 22 of the present invention provides pressure in the pre-oxidation chamber, so that the carbon soot in the upper chamber 23 of the pre-oxidation chamber has sufficient pressure to be sprayed into the secondary burner 3, and the fan speed can be changed by operating the controller of the fan, thereby achieving the effect of regulating the flow rate; the arrangement of the windshield 219 prevents the fan suction from affecting the flame of the primary burner 1; at the same time, the windshield 219 is designed as a hexagonal hollow array structure, which can reduce the throttling loss of the fan 22 during the suction process; the collecting device 4 of the present invention is designed as a lifting mechanism, and carbon nanotubes in different reaction temperature zones can be prepared by adjusting the height.

[0028] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. An integrated burner system for efficiently preparing carbon nanotubes, characterized in that: It comprises a primary burner (1), a pre-oxidation chamber (2), and a secondary burner (3); the upper part of the primary burner (1) is connected to the pre-oxidation chamber (2), and the upper part of the pre-oxidation chamber (2) is connected to the secondary burner (3); a collecting device (4) is arranged above the secondary burner (3); The pre-oxidation chamber (2) is composed of a lower chamber (21), a fan (22) and an upper chamber (23); the lower chamber (21) is arranged as a convergent-convergent nozzle structure, the upper chamber (23) is arranged as a constricted structure, a cooling water channel (24) is arranged on the periphery of the inner wall of the pre-oxidation chamber (2), a water inlet a (241) is arranged at the connection between the cooling water channel (24) and the top of the upper chamber (23), a water outlet b (244) is arranged at the connection between the cooling water channel (24) and the bottom of the lower chamber (21), and an ignition electrode (211) is arranged above the water outlet b (244); The lower chamber (21) comprises an inlet section (212), a contraction section (213), a throat (214), a diffusion section (215), and an outlet section (216); the first-stage burner (1) is connected to the inlet section (212); the contraction section (213) is arranged in communication with the upper part of the inlet section (212); the throat (214) is arranged in communication with the upper part of the contraction section (213), and the diffusion section (215) is arranged in communication with the upper part of the throat (214); the outlet section (216) is arranged in communication with the upper part of the diffusion section (215); The inlet section (212), the contraction section (213), the throat (214), the diffusion section (215) and the outlet section (216) constitute a convergent-convergent nozzle structure. The convergent-convergent nozzle structure can prevent the carbon smoke from falling due to insufficient power when it rises to a certain height, thereby ensuring that the carbon smoke has sufficient buoyancy.

2. The integrated burner system for efficiently preparing carbon nanotubes according to claim 1, characterized in that: The contraction section (213) and the diffusion section (215) are arranged obliquely along the length direction of the vertical throat section (214).

3. The integrated burner system for efficiently preparing carbon nanotubes according to claim 1, characterized in that: The contraction section (213) has an inclination angle of 20°, and the diffusion section (215) has an inclination angle of 15°.

4. The integrated burner system for efficiently preparing carbon nanotubes according to claim 1, characterized in that: An air nozzle (217) and a fuel nozzle a (218) are arranged on both sides of the diffuser section (215), respectively. The air nozzle (217) and the fuel nozzle a (218) are arranged perpendicular to the diffuser section (215).

5. The integrated burner system for efficiently preparing carbon nanotubes according to claim 1, characterized in that: The fan (22) comprises a connection port a (221) and a connection port b (222), wherein the connection port a (221) is connected to the lower chamber outlet section (216); the connection port b (222) is connected to the upper chamber (23); a windshield (219) is arranged at the lower end of the connection port a (221), wherein the windshield (219) can prevent the fan (22) from inhaling air and affecting the flame of the primary burner (1), and the windshield (219) adopts a hexagonal hollow array structure to reduce the throttling loss of the fan (22) during the air inhalation process.

6. The integrated burner system for efficiently preparing carbon nanotubes according to claim 1, characterized in that: A water inlet b (243) is arranged below the connection between the connection port a (221) and the lower chamber (21); a water outlet a (242) is arranged above the connection between the connection port b (222) and the upper chamber (23); and the water outlet a (242) and the water inlet b (243) are connected by a cooling water pipe.

7. The integrated burner system for efficiently preparing carbon nanotubes according to claim 1, characterized in that: A fuel nozzle b (231) is arranged at the end of the constricted structure of the upper chamber (23); the fuel nozzle b (231) is connected to the secondary burner (3) by a stainless steel pipeline.

8. The integrated burner system for efficiently preparing carbon nanotubes according to claim 1, characterized in that: A collecting device (4) is arranged above the secondary burner (3), wherein the collecting device (4) comprises a lifting mechanism (41) and a base plate (42), wherein the base plate (42) is placed on the lifting mechanism (41).

9. The method for using the integrated burner system for efficiently preparing carbon nanotubes according to any one of claims 1 to 8, characterized in that: The specific steps are as follows: Step 1: Open the constant temperature water tank I and the constant temperature water tank II to keep the primary burner and the secondary burner at a constant temperature; introduce cooling water into the water inlet a; Step 2: Open the intake valve I, intake valve II, intake valve III and flowmeter I, flowmeter II, flowmeter III, and use the ignition electrode to ignite the first-stage burner to generate carbon smoke; Step 3: Open the air inlet valve IV, the air inlet valve V and the flowmeter IV, the flowmeter V, and introduce air and fuel into the air nozzle and the fuel nozzle of the diffusion section of the lower chamber of the pre-oxidation chamber respectively, and fully mix with the soot to form a combustible mixed gas; Step 4: Control the motor speed through the fan controller, so that the combustible mixed gas enters the secondary burner, and turn on the flow meter VI at the same time; Step 5: Ignite the secondary burner, the soot is captured by the substrate, and the carbon source is catalytically decomposed on its surface to generate carbon nanotubes.

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