Array type multi-tube cracking furnace for preparing carbon nanotubes

Abstract

The array type multi-tube cracking furnace comprises a high-temperature hearth (200), a plurality of furnace tubes (100) penetrating through the hearth and a heat supply component (300), the whole high-temperature hearth (200) is a square heat preservation hearth, and the furnace wall, a top plate and a bottom plate of the hearth are all made of high-temperature heat insulation materials; the interior of the high-temperature hearth (200) is a high-temperature gas phase space; a hearth shell (400) is arranged on the outer side of the high-temperature hearth (200); the furnace tubes (100) are mounted in the high-temperature hearth (200) in a manner of a plurality of vertical arrays; the upper end opening (103) of the furnace tube penetrates out of an upper top plate of the high-temperature hearth (200), and the lower end opening (104) of the furnace tube penetrates through a lower bottom plate of the high-temperature hearth (200) and is vertically mounted in the high-temperature hearth (200), so that the middle part of the furnace tube (100) is arranged in an internal high-temperature area of the high-temperature hearth (200). According to the scheme, combined heat supply of the cracking furnace and continuous feeding and continuous production of multiple furnace tubes can be realized, so that large-scale continuous production of high-quality carbon nanotubes with relatively low cost is achieved.

Description

Technical Field

[0001] The utility model relates to the field of carbon nanotube detection, in particular to an array multi-tube cracking furnace for carbon nanotube preparation. Background Art

[0002] Since carbon nanotubes were discovered by Japanese scientists in 1991, due to their unique structure and excellent mechanical, electrical, optical, and thermal properties, they have quickly shown great application potential in the fields of electronic devices, composite materials, sensors, energy batteries, biomedicine, etc. The key to the production technology of carbon nanotubes is the reaction furnace part. The preparation methods usually include arc discharge method, laser evaporation method, and chemical vapor deposition (CVD) method. Among them, the CVD method is a widely used process at present because of its relatively simple device structure. The commonly used equipment for producing carbon nanotubes by CVD method mainly includes CVD reaction furnace, material transport system, heating system, and control system, etc. The CVD reaction furnace is the core component, which provides a high-temperature environment for the reaction gas to decompose and deposit to form carbon nanotubes under the action of a catalyst. Since high-quality carbon nanotubes are required to be produced under high-temperature conditions and precise temperature control is needed during the production process by CVD method, currently, most of the industry uses a single-channel resistance furnace as the CVD reaction furnace for nanotubes. However, due to the limited throughput of this scheme, batch production cannot be achieved, and the energy consumption of the electrothermal system is relatively high, and the economy is poor, which limits the large-scale production. Another carbon nanotube preparation scheme widely used in the industry is the fluidized bed reactor scheme. The characteristics of this scheme are that the process and reactor structure are relatively complex. Although the growth rate of carbon nanotubes in this scheme is relatively fast, the purity and quality of carbon nanotube products are poor, and the market application of products is limited. At the same time, there are many operating parameters in the fluidized bed process, such as temperature, pressure, gas flow rate, catalyst type and concentration, etc. The multi-factor control causes the complexity and regulation difficulty of the process, and the failure rate is high, which affects the production stability. Summary of the Utility Model

[0003] The purpose of the utility model is to overcome the deficiencies of the above-mentioned existing technologies, so that the carbon nanotube preparation device meets the requirements of large-scale continuous production, and improves the energy utilization rate and reduces the comprehensive cost.

[0004] The utility model provides an array multi-tube cracking furnace for carbon nanotube preparation, including a high-temperature furnace chamber, multiple furnace tubes penetrating the furnace chamber, and a heat supply component, and is characterized in that:

[0005] The high-temperature furnace chamber is an overall square heat-insulating furnace chamber, and the furnace wall, roof, and bottom plate of the furnace chamber are all high-temperature heat-insulating materials; the inside of the high-temperature furnace chamber is a high-temperature gas phase space; there is a furnace chamber shell outside the high-temperature furnace chamber;

[0006] The furnace tubes are installed in the high-temperature furnace chamber in a multi-vertical-array manner;

[0007] The length of the furnace tube is greater than the height of the high-temperature furnace chamber. The upper port of the furnace tube penetrates through the upper roof of the high-temperature furnace chamber, and the lower port of the furnace tube passes through the lower bottom plate and is vertically installed in the high-temperature furnace chamber, so that the middle part of the furnace tube is placed in the internal high-temperature area of the high-temperature furnace chamber.

[0008] Furthermore, the furnace tube has an outer wall and an inner wall of the furnace tube; the outer wall of the furnace tube is a heat-absorbing surface for receiving the radiant heat of the heat supply component; the inner wall of the furnace tube is a heat-releasing surface for supplying heat to the cracking raw material passing through the furnace tube.

[0009] Furthermore, the heat supply components are uniformly installed in the high-temperature furnace chamber.

[0010] Furthermore, a plurality of heat supply components are uniformly installed around the furnace tubes arranged in an array, and a group of heat supply components simultaneously provide uniform radiant heat for a plurality of furnace tubes.

[0011] Furthermore, the heat supply components include two structures: a monomeric type and an integrated type.

[0012] The utility model has the following beneficial effects:

[0013] (1) An array-type multi-tube cracking furnace for carbon nanotube preparation of the utility model realizes the combined heat supply of the cracking furnace and the continuous feeding and continuous production of multiple furnace tubes by arranging a plurality of furnace tubes in an array in the high-temperature furnace chamber and uniformly installing heat supply components, so as to achieve the continuous production of large-scale high-quality carbon nanotubes at a lower cost; and the structure of the utility model is simple and convenient to manufacture.

[0014] (2) Since the CVD method for preparing high-quality carbon nanotubes requires precise control of high-temperature conditions, under the same heat source conditions, the heat absorption accuracy control of small-sized furnace tubes is easier than that of large-sized furnace tubes. The utility model adopts the scheme of arranging a plurality of small-sized furnace tubes in an array in the high-temperature furnace chamber, so that while the overall cracking furnace has a large throughput, it can largely meet the requirements of uniform heating of the materials passing through the furnace tubes and precise temperature control. This design not only makes the cracking furnace structure compact and has a high integration degree, but also makes the quality of the produced carbon nanotubes higher and more stable.

[0015] (3) The utility model adopts the scheme of uniformly arranging heat supply components at the gaps between the furnace tubes arranged in an array and uniformly controlling them, so that all furnace tubes absorb heat more uniformly and the temperature control is more precise. This scheme makes the overall heat source utilization rate of the cracking furnace high, thereby further improving production efficiency and reducing production costs.

[0016] (4) The combined heating and reasonable furnace body structure design adopted by the cracking furnace of the utility model enable the continuous input of the carbon source material and the continuous output of the cracking products of the equipment, so that it can simultaneously and continuously crack the carbon source in multiple furnace tubes, thereby realizing the continuous production of carbon nanotubes without frequent shutdown or refueling. Compared with the single-tube furnace commonly used in the current market, this greatly improves the single-unit production capacity of the equipment. Brief Description of the Drawings

[0017] Figure 1 is the front view of the array multi-tube cracking furnace;

[0018] Figure 2 is the schematic diagram of the material flow of the array multi-tube cracking furnace;

[0019] Figure 3 is the schematic diagram of the installation of the heating component;

[0020] Figure 4 is the schematic diagram of the installation of another heating component.

[0021] Wherein: 100 - furnace tube; 200 - high-temperature furnace chamber; 300 - heating component; 400 - furnace chamber shell; 500 - cracking raw material; 600 - cracking product; 101 - inner wall of the furnace tube; 102 - outer wall of the furnace tube; 103 - upper port of the furnace tube; 104 - lower port of the furnace tube; 201 - upper top plate of the high-temperature furnace chamber; 202 - lower bottom plate of the high-temperature furnace chamber; 301 - high-temperature section of the heating component; 302 - low-temperature section of the heating component. Detailed Description of the Preferred Embodiment

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Figures 1-4

[0023] Figure 1 As shown, this embodiment provides an array multi-tube cracking furnace for the preparation of carbon nanotubes, which is composed of a high-temperature furnace chamber 200, multiple furnace tubes 100 penetrating the furnace chamber, and a heating component 300.

[0024] The high-temperature furnace chamber 200 is a square structure as a whole, and the furnace chamber wall, top plate and bottom plate are all made of high-temperature heat-insulating materials. The inside of the high-temperature furnace chamber 200 is a high-temperature gas phase space.

[0025] The outside of the high-temperature furnace chamber 200 is completely surrounded by a furnace chamber shell 400, and the furnace chamber shell 400 provides strength support, heat preservation and sealing functions for the high-temperature furnace chamber 200.

[0026] The material of the furnace tube 100 is a high-temperature resistant material, which can be a high-temperature resistant non-metallic material or a high-temperature resistant alloy material.

[0027] ​​

[0028] As Figure 1 , Figure 2 shown, the length of the furnace tube 100 is greater than the height of the high-temperature furnace chamber 200. The upper port 103 of the furnace tube penetrates through the upper top plate 201 of the high-temperature furnace chamber, and the lower port 104 of the furnace tube passes through the lower bottom plate 202 of the high-temperature furnace chamber and is vertically installed in the high-temperature furnace chamber, so that the middle part of the furnace tube 100 is placed in the internal high-temperature area of the high-temperature furnace chamber.

[0029] The furnace tube 100 has a furnace tube outer wall 102 and a furnace tube inner wall 101. The furnace tube outer wall 102 is a heat absorption surface for receiving the radiant heat of the heat supply component 300. The furnace tube inner wall 101 is a heat release surface for supplying heat to the cracking raw material 500 passing through the furnace tube.

[0030] The heat supply components 300 are uniformly installed in the high-temperature furnace chamber 200 to provide a uniform high-temperature temperature field for the furnace chamber 200.

[0031] The plurality of heat supply components 300 are uniformly installed around the furnace tubes 100 arranged in an array. This installation method can enable a group of heat supply components 300 to simultaneously provide uniform radiant heat to multiple furnace tubes 100.

[0032] As Figures 3-4 shown, the heat supply component 300 is an electric heating element and has two structures: a monomeric type and an integrated type. The monomeric heat supply component is a single electric heating element independently connected to electricity and independently supplying heat. The two ends of the monomeric heat supply component both penetrate through the high-temperature furnace chamber 200 and the furnace chamber shell 400 for wiring; the integrated heat supply component is an integral type. The heat supply component 300 can be made of metal resistance wire, non-metal electric heating element or composite material.

[0033] As Figure 2 shown, the integrated design of the present invention enables multiple furnace tubes 100 to synchronously and continuously input the cracking raw material 500 and continuously output the cracking product 600, which greatly improves the production capacity of a single device. The cracking raw material 500 is mainly a carbon source and a catalyst, and the cracking product 600 is mainly a macroscopic carbon nanotube body.

[0034] The above is only a preferred solution of the present invention. Therefore, all equivalent changes made according to the structures, features and principles described in the scope of the present invention application are included in the scope of the present invention application. Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An array multi-tube cracking furnace for carbon nanotube preparation, comprising a high-temperature furnace chamber (200), multiple furnace tubes (100) penetrating the furnace chamber, and a heat supply component (300), characterized in that: The high-temperature furnace chamber (200) is an overall square heat-insulated furnace chamber, and the furnace chamber wall, roof and bottom plate are all made of high-temperature heat-insulating materials; the inside of the high-temperature furnace chamber (200) is a high-temperature gas phase space; there is a furnace chamber outer shell (400) outside the high-temperature furnace chamber (200); The furnace tubes (100) are installed in the high-temperature furnace chamber (200) in a multi-row vertical array manner; The length of the furnace tube (100) is greater than the height of the high-temperature furnace chamber (200). The upper port (103) of the furnace tube penetrates the upper roof of the high-temperature furnace chamber (200), and the lower port (104) of the furnace tube passes through the lower bottom plate of the high-temperature furnace chamber (200) and is vertically installed in the high-temperature furnace chamber (200), so that the middle part of the furnace tube (100) is placed in the internal high-temperature area of the high-temperature furnace chamber (200).

2. The array multi-tube cracking furnace for carbon nanotube preparation according to claim 1, characterized in that: The furnace tube (100) has a furnace tube outer wall (102) and a furnace tube inner wall (101); the furnace tube outer wall (102) is a heat absorption surface for receiving the radiant heat of the heat supply component (300); the furnace tube inner wall (101) is a heat release surface for supplying heat to the cracking raw material passing through the furnace tube (100).

3. The array multi-tube cracking furnace for carbon nanotube preparation according to claim 1, wherein: The heat supply component (300) is uniformly installed in the high-temperature furnace chamber (200).

4. The array multi-tube cracking furnace for carbon nanotube preparation according to claim 3, wherein: Multiple heat supply components (300) are uniformly installed around the furnace tubes (100) arranged in an array, and a group of heat supply components (300) simultaneously provides uniform radiant heat for multiple furnace tubes (100).

5. The array multi-tube cracking furnace for carbon nanotube preparation according to claim 3, characterized in that: The heat supply component (300) includes two structures: a monomeric type and an integrated type.

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