Carbon coating heating tube and preparation method

Abstract

The present invention relates to the technical field of carbon-coated heating tubes, and discloses a carbon-coated heating tube and a preparation method thereof, wherein the carbon-coated heating tube comprises: a quartz tube, with tube heads for mounting electrodes provided at both ends of the quartz tube, and a conductive carbon slurry coating coated on the inner wall of the quartz tube; an end substrate provided on the inner wall of the tube head, the end substrate comprising a basic thermal insulation layer and a pressure release layer; the basic thermal insulation layer being an aerogel layer coated on the tube head; a pressure release layer provided outside the aerogel layer; an insulating plug, with electrodes mounted outside the insulating plug, and molybdenum wire provided inside the insulating plug; the insulating plug being mounted on the tube head to form a seal on the tube head. The present application coats the tube heads at both ends of the quartz tube with an aerogel layer for thermal insulation, and simultaneously provides a pressure release layer formed by winding ceramic fibers outside the aerogel layer; when high pressure is generated inside the quartz tube, the high pressure inside the quartz tube can be released through a pressure release chamber.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon coating heating tubes, and in particular to a carbon coating heating tube and a preparation method thereof. Background Art

[0002] The structure of a traditional infrared heating tube basically consists of a quartz tube, an insulating plug, electrodes, and a heating wire. When the heating wire generates heat inside the quartz tube, the entire quartz tube is heated. Long-term use can cause the contact area with the insulating plug to partially or completely fall off, causing damage to the heating tube. Extensive testing has found that this phenomenon is related to the treatment process at the connection point between the insulating plug and the quartz tube. In addition, during use, the pressure inside the quartz tube increases with temperature, resulting in a high pressure inside the quartz tube, which accelerates the shedding of the contact area between the insulating plug and the quartz tube. Summary of the Invention

[0003] In view of this, an object of the present invention is to provide a carbon-coated heating tube and a preparation method thereof.

[0004] To achieve the above objectives, the present invention provides a carbon-coated heating tube, comprising:

[0005] The quartz tube has tube heads for electrode installation at both ends, and the inner wall of the quartz tube is coated with a conductive carbon slurry coating.

[0006] An end head substrate is provided on the inner wall of the pipe head, and comprises a basic heat insulation layer and a pressure release layer;

[0007] The basic thermal insulation layer is an aerogel layer coated on the pipe head for thermal insulation;

[0008] A pressure release layer formed by winding ceramic fibers is provided outside the aerogel layer, and the ceramic fibers form peaks and valleys with uniform intervals during the winding process; pressure release grooves are formed between the peaks and valleys;

[0009] A metal powder-doped silica composite interface material is coated on the pressure release layer and fully covers the aerogel layer; wherein the metal powder-doped silica composite interface material forms a honeycomb pore structure for pressure release in the pressure release groove;

[0010] An insulating plug, wherein the electrode is installed on the outside of the insulating plug, and a molybdenum wire is provided inside the insulating plug. One end of the molybdenum wire is connected to the electrode, and the other end of the molybdenum wire is spirally wound along the inner wall of the quartz tube and connected to the conductive carbon paste coating; the insulating plug is installed on the tube head to form a seal for the tube head.

[0011] Furthermore, the width of the pressure release groove gradually increases from the inside to the outside.

[0012] Furthermore, the pressure release layer forms a 3-5° slope from the inside to the outside, and the pressure release groove is extended through the slope. When the silicon dioxide composite interface material doped with metal powder is filled in the pressure release groove, a honeycomb hole structure with an extended slope is formed.

[0013] Furthermore, the metal powder-doped silicon dioxide composite interface material includes:

[0014] at least one metal powder for heat conduction;

[0015] Aerogels doped with silica particles;

[0016] Calculated by mass percentage, the silica particles account for 55-75% of the aerogel.

[0017] Furthermore, the metal powder is one or both of copper and tungsten.

[0018] Furthermore, the pressure release layer is formed by statically wrapping ceramic fibers on a mold and then bonding the ceramic fibers to the aerogel layer.

[0019] Furthermore, the insulating plug includes:

[0020] The insulating cover body is formed of ceramic material, and a plug body portion for mounting with the tube head is provided at the lower part of the insulating cover body. The inner side of the plug body portion is provided with a mounting groove for mounting the pole body; a honeycomb plug is provided along the inner wall of the mounting groove, and the honeycomb plug is provided in an annular shape;

[0021] A pole body for fixing the molybdenum wire is installed in the installation groove, and a through hole for installing the molybdenum wire is provided in the middle part of the pole body; and

[0022] A notch is provided on the upper portion of the pole body along the outer wall of the pole body. When the pole body is installed in the installation groove, the notch contacts the honeycomb plug and is relatively closed to form a pressure release chamber.

[0023] Furthermore, when the insulating plug is mounted on the tube head, the honeycomb hole structure for pressure release formed on the tube head is arranged corresponding to the honeycomb plug.

[0024] The present invention also provides a method for preparing a carbon-coated heating tube, comprising the following steps:

[0025] 1) Cut the quartz tube to the required length, clean and dry it, and then send it to the coating process;

[0026] 2) spraying a conductive carbon slurry coating on the inner wall of the quartz tube and drying it;

[0027] 3) The tube head is determined by measuring and positioning on both sides of the quartz tube, and an aerogel layer is coated inside the tube head for thermal insulation;

[0028] 4) A pressure release layer formed by winding ceramic fibers is provided outside the aerogel layer, and the ceramic fibers form evenly spaced peaks and valleys during the winding process; pressure release grooves are formed between the peaks and valleys;

[0029] 5) coating the metal powder-doped silica composite interface material on the pressure release layer and fully covering the aerogel layer; wherein the metal powder-doped silica composite interface material forms a honeycomb pore structure for pressure release in the pressure release groove;

[0030] 6) Insert two insulating plugs into the tube heads respectively so that the molybdenum wire inside the insulating plugs is connected to the conductive carbon paste coating.

[0031] Furthermore, the pressure release layer forms a 3-5° slope from the inside to the outside, and the pressure release groove is extended by the slope. When the silicon dioxide composite interface material doped with metal powder is filled in the pressure release groove, a honeycomb pore structure with an extended slope is formed;

[0032] Silica composite interface materials doped with metal powder include:

[0033] at least one metal powder for heat conduction;

[0034] Aerogels doped with silica particles;

[0035] Calculated by mass percentage, the silica particles account for 55-75% of the aerogel.

[0036] The present application is to coat a layer of aerogel for heat insulation on the tube heads at both ends of the quartz tube, and at the same time, provide a pressure release layer formed by winding ceramic fibers outside the aerogel layer; on the one hand, the ceramic fibers have low thermal conductivity properties, and on the other hand, a silica composite interface material doped with metal powder is coated in a pressure release groove made of ceramic fibers, wherein the silica composite interface material doped with metal powder forms a honeycomb hole structure for pressure release in the pressure release groove; in this way, when high pressure is generated inside the quartz tube, it can release the high pressure inside the quartz tube through the honeycomb hole structure and the corresponding pressure release cavity.

[0037] Based on the above, the aerogel layer and the pressure release layer formed by winding ceramic fibers can effectively form two layers of thermal insulation, so that the quartz tube cannot directly apply heat to the contact part with the insulating plug at the tube head. At the same time, through effective pressure release, the insulating plug and the quartz tube installation part are effectively protected.

[0038] Compared with traditional infrared heating tubes, the present invention uses a conductive carbon paste coating instead of a heating wire, and coats the conductive carbon paste coating on the inner wall of the quartz tube, thereby reducing thermal resistance, improving heat exchange efficiency and infrared conversion efficiency, extending the working life in the high-temperature domain, reducing heat loss of the quick-heating tube during the heating process, and improving power utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic structural diagram of the carbon coating heating tube of the present invention;

[0040] Figure 2 Schematic diagram of the structure of the insulating plug in the present invention;

[0041] Figure 3 Schematic diagram of the structure of the tube head in the present invention;

[0042] Figure 4 Schematic diagram of the connection between molybdenum wire and conductive carbon paste coating;

[0043] In the figure, 1. Insulating plug; 10. Electrode; 11. Insulating cover body; 12. Plug body; 13. Honeycomb plug; 14. Notch; 15. Pole body; 16. Molybdenum wire; 2. Quartz tube; 20. Tube head; 21. Basic insulation layer; 22. Pressure release layer; 3. Conductive carbon paste coating. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] Example 1

[0046] Reference Figures 1 to 2 The present application proposes a carbon-coated heating tube, comprising:

[0047] A quartz tube 2, with tube heads 20 for mounting electrodes 10 provided at both ends of the quartz tube 2, and a conductive carbon slurry coating 3 coated on the inner wall of the quartz tube 2;

[0048] An end head substrate is provided on the inner wall of the pipe head 20 and includes a basic heat insulation layer 21 and a pressure release layer 22;

[0049] The basic heat insulation layer 21 is an aerogel layer coated on the tube head 20 for heat insulation;

[0050] A pressure release layer 22 formed by winding ceramic fibers is provided outside the aerogel layer, and the ceramic fibers form peaks and valleys with uniform spacing during the winding process; pressure release grooves are formed between the peaks and valleys;

[0051] A metal powder-doped silica composite interface material is coated on the pressure release layer 22 and fully covers the aerogel layer; wherein the metal powder-doped silica composite interface material forms a honeycomb pore structure for pressure release in the pressure release groove;

[0052] The insulating plug 1 and the electrode 10 are installed on the outside of the insulating plug 1. A molybdenum wire 16 is provided inside the insulating plug 1. One end of the molybdenum wire 16 is conductively connected to the electrode 10. The other end of the molybdenum wire 16 is spirally wound along the inner wall of the quartz tube 2 and connected to the conductive carbon paste coating 3. The insulating plug 1 is installed on the tube head 20 to form a seal on the tube head 20.

[0053] In the above, refer to Figure 3 The basic thermal insulation layer 21 is arranged from left to right (that is, from the inside to the outside of the quartz tube 2), and its arrangement length is to fully cover the tube head 20. The length of the pressure release layer 22 formed by winding ceramic fibers is two-thirds of the tube head 20, and the remaining one-third is used to fix with the insulating plug 1; and when the pressure release groove is coated with the silica composite interface material of mixed metal powder, the pressure release groove is completely filled and extended to be coated on the basic thermal insulation layer 21. In this way, the pressure release layer 22 forms a 3-5° slope from the inside to the outside, and the pressure release groove is extended through the slope. When the silica composite interface material doped with metal powder is filled in the pressure release groove, a honeycomb hole structure with an extended slope is formed.

[0054] In the above description, the metal powder-doped silica composite interface material comprises: at least one metal powder for heat conduction; and an aerogel doped with silica particles; wherein, by mass, the silica particles comprise 55-75% of the aerogel. Furthermore, the metal powder is one or both of copper and tungsten. It should be noted that the aerogel in this application is silica aerogel.

[0055] In the above, when silica particles are arranged in the aerogel, the gaps formed between the silica particles are the basis for forming the honeycomb pore structure;

[0056] In the above description, the pressure-releasing layer 22 is formed by wrapping ceramic fibers around a mold, statically pressing, and then bonding them to the aerogel layer. It should be noted that the mold itself has a 3-5° slope and grooves formed by peaks and valleys. After wrapping, the ceramic fibers must be adapted to the static pressure and remain within the mold during static pressure.

[0057] In the above description, the insulating plug 1 comprises: an insulating cover body 11 formed of a ceramic material. A plug body portion 12 for mounting with a tube head 20 is disposed at the lower portion of the insulating cover body 11. A mounting groove for mounting a pole body 15 is provided inside the plug body portion 12. A circular honeycomb plug 13 is disposed along the inner wall of the mounting groove. A pole body 15 for securing a molybdenum wire 16 is mounted within the mounting groove. A through hole for mounting the molybdenum wire 16 is provided in the middle of the pole body 15. A notch 14 is formed along the outer wall of the pole body 15 at the upper portion of the pole body 15. When the pole body 15 is mounted within the mounting groove, the notch 14 contacts the honeycomb plug 13, relatively sealing the notch 14 to form a pressure relief chamber. When the insulating plug 1 is mounted on the tube head 20, the honeycomb pore structure for pressure relief formed in the tube head 20 corresponds to the honeycomb plug 13.

[0058] This invention involves coating the tube heads 20 at both ends of a quartz tube 2 with an aerogel layer for thermal insulation, and simultaneously providing a pressure release layer 22 formed by winding ceramic fibers outside the aerogel layer. Ceramic fibers have low thermal conductivity, and a metal-doped silica composite interface material is coated within pressure release grooves formed from the ceramic fibers. The metal-doped silica composite interface material forms a honeycomb pore structure for pressure release within the pressure release grooves. Thus, when high pressure is generated within the quartz tube 2, it is released through the honeycomb pore structure and the corresponding pressure release cavity. Based on the above, the aerogel layer and the pressure release layer 22 formed by winding ceramic fibers effectively form two layers of thermal insulation, preventing the quartz tube 2 from directly applying heat to the contact portion with the insulating plug 1 at the tube head 20. Furthermore, effective pressure release effectively protects the insulating plug 1 and the mounting portion of the quartz tube 2.

[0059] In the above, the doped metal powder is to form a certain heat transfer in the honeycomb pore structure. Under high temperature and high pressure, a certain heat transfer is conducive to the release of pressure in the honeycomb pores.

[0060] Example 2

[0061] The present invention also provides a method for preparing a carbon-coated heating tube, comprising the following steps:

[0062] 1) Cut the quartz tube 2 to the required length, clean and dry it, and then send it to the coating process;

[0063] 2) spraying a conductive carbon slurry coating 3 on the inner wall of the quartz tube 2 and drying it;

[0064] 3) The tube head 20 is determined by measuring and positioning on both sides of the quartz tube 2, and an aerogel layer for heat insulation is coated inside the tube head 20;

[0065] 4) A pressure release layer 22 formed by winding ceramic fibers is provided outside the aerogel layer, and the ceramic fibers form evenly spaced peaks and valleys during the winding process; pressure release grooves are formed between the peaks and valleys;

[0066] 5) coating the metal powder-doped silica composite interface material on the pressure release layer 22 and fully covering the aerogel layer; wherein the metal powder-doped silica composite interface material forms a honeycomb pore structure for pressure release in the pressure release groove;

[0067] 6) Insert the two insulating plugs 1 into the tube head 20 respectively, so that the molybdenum wire 16 inside the insulating plug 1 is connected to the conductive carbon paste coating 3.

[0068] In the above, the pressure release layer 22 forms a 3-5° slope from the inside to the outside, and the slope is used to extend the pressure release groove. When the silicon dioxide composite interface material doped with metal powder is filled in the pressure release groove, a honeycomb pore structure with an extended slope is formed;

[0069] Silica composite interface materials doped with metal powder include:

[0070] at least one metal powder for heat conduction;

[0071] Aerogels doped with silica particles;

[0072] Calculated by mass percentage, the silica particles account for 55-75% of the aerogel.

[0073] In the above, refer to Figure 3 The basic thermal insulation layer 21 is arranged from left to right (that is, from the inside to the outside of the quartz tube 2), and its arrangement length is to fully cover the tube head 20. The length of the pressure release layer 22 formed by winding ceramic fibers is two-thirds of the tube head 20, and the remaining one-third is used to fix with the insulating plug 1; and when the pressure release groove is coated with the silica composite interface material of mixed metal powder, the pressure release groove is completely filled and extended to be coated on the basic thermal insulation layer 21. In this way, the pressure release layer 22 forms a 3-5° slope from the inside to the outside, and the pressure release groove is extended through the slope. When the silica composite interface material doped with metal powder is filled in the pressure release groove, a honeycomb hole structure with an extended slope is formed.

[0074] In the above description, the metal powder-doped silica composite interface material comprises: at least one metal powder for heat conduction; and an aerogel doped with silica particles; wherein, by mass, the silica particles comprise 55-75% of the aerogel. Furthermore, the metal powder is one or both of copper and tungsten. It should be noted that the aerogel in this application is silica aerogel.

[0075] In the above, when silica particles are arranged in the aerogel, the gaps formed between the silica particles are the basis for forming the honeycomb pore structure;

[0076] In the above description, the pressure-releasing layer 22 is formed by wrapping ceramic fibers around a mold, statically pressing, and then bonding them to the aerogel layer. It should be noted that the mold itself has a 3-5° slope and grooves formed by peaks and valleys. After wrapping, the ceramic fibers must be adapted to the static pressure and remain within the mold during static pressure.

[0077] This invention involves coating the tube heads 20 at both ends of a quartz tube 2 with an aerogel layer for thermal insulation, and simultaneously providing a pressure release layer 22 formed by winding ceramic fibers outside the aerogel layer. Ceramic fibers have low thermal conductivity, and a metal-doped silica composite interface material is coated within pressure release grooves formed from the ceramic fibers. The metal-doped silica composite interface material forms a honeycomb pore structure for pressure release within the pressure release grooves. Thus, when high pressure is generated within the quartz tube 2, it is released through the honeycomb pore structure and the corresponding pressure release cavity. Based on the above, the aerogel layer and the pressure release layer 22 formed by winding ceramic fibers effectively form two layers of thermal insulation, preventing the quartz tube 2 from directly applying heat to the contact portion with the insulating plug 1 at the tube head 20. Furthermore, effective pressure release effectively protects the insulating plug 1 and the mounting portion of the quartz tube 2.

[0078] In the above, the doped metal powder is to form a certain heat transfer in the honeycomb pore structure. Under high temperature and high pressure, a certain heat transfer is conducive to the release of pressure in the honeycomb pores.

[0079] It should also be noted that when the tube head 20 is fixed to the insulating plug 1, the plug body part 12 of the insulating plug 1 adopts a sealing structure in the form of a flange assembly. The quartz tube 2 and the flange assembly are sealed and connected, and the sealing performance meets the requirements of high temperature and high pressure.

[0080] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. Carbon coated heating tube, characterized in that, include: A quartz tube, with tube heads for electrode installation provided at both ends of the quartz tube, and a conductive carbon slurry coating coated on the inner wall of the quartz tube; An end head substrate is provided on the inner wall of the pipe head, and comprises a basic heat insulation layer and a pressure release layer; The basic thermal insulation layer is an aerogel layer coated on the pipe head for thermal insulation; A pressure release layer formed by winding ceramic fibers is provided outside the aerogel layer, and the ceramic fibers form peaks and valleys with uniform intervals during the winding process; pressure release grooves are formed between the peaks and valleys; A metal powder-doped silica composite interface material is coated on the pressure release layer and fully covers the aerogel layer; wherein the metal powder-doped silica composite interface material forms a honeycomb pore structure for pressure release in the pressure release groove; An insulating plug, wherein the electrode is installed on the outside of the insulating plug, and a molybdenum wire is provided inside the insulating plug. One end of the molybdenum wire is connected to the electrode, and the other end of the molybdenum wire is spirally wound along the inner wall of the quartz tube and connected to the conductive carbon paste coating; the insulating plug is installed on the tube head to form a seal for the tube head.

2. The carbon-coated heating tube according to claim 1, characterized in that: The width of the pressure release groove gradually increases from the inside to the outside.

3. The carbon-coated heating tube according to claim 1, characterized in that: The pressure release layer forms a 3-5° slope from the inside to the outside, and the pressure release groove is extended through the slope. When the silicon dioxide composite interface material doped with metal powder is filled in the pressure release groove, a honeycomb hole structure with an extended slope is formed.

4. The carbon-coated heating tube according to claim 1, characterized in that: Silica composite interface materials doped with metal powder include: at least one metal powder for heat conduction; Aerogels doped with silica particles; Calculated by mass percentage, the silica particles account for 55-75% of the aerogel.

5. The carbon-coated heating tube according to claim 4, characterized in that: The metal powder is one or both of copper and tungsten.

6. The carbon-coated heating tube according to claim 1, characterized in that: The pressure release layer is formed by winding ceramic fibers on a mold and then statically pressing the ceramic fibers and then bonding the ceramic fibers to the aerogel layer.

7. The carbon-coated heating tube according to claim 1, characterized in that: The insulating plug comprises: The insulating cover body is formed of ceramic material, and a plug body portion for mounting with the tube head is provided at the lower part of the insulating cover body. The inner side of the plug body portion is provided with a mounting groove for mounting the pole body; a honeycomb plug is provided along the inner wall of the mounting groove, and the honeycomb plug is provided in an annular shape; A pole body for fixing the molybdenum wire is installed in the installation groove, and a through hole for installing the molybdenum wire is provided in the middle part of the pole body; and A notch is provided on the upper portion of the pole body along the outer wall of the pole body. When the pole body is installed in the installation groove, the notch contacts the honeycomb plug and is relatively closed to form a pressure release chamber.

8. The carbon-coated heating tube according to claim 1, characterized in that: When the insulating plug is mounted on the tube head, the honeycomb hole structure for pressure release formed on the tube head is arranged corresponding to the honeycomb plug.

9. A method for preparing a carbon-coated heating tube, characterized in that: The steps include: 1) Cut the quartz tube to the required length, clean and dry it, and then send it to the coating process; 2) spraying a conductive carbon slurry coating on the inner wall of the quartz tube and drying it; 3) The tube head is determined by measuring and positioning on both sides of the quartz tube, and an aerogel layer is coated inside the tube head for thermal insulation; 4) A pressure release layer formed by winding ceramic fibers is provided outside the aerogel layer, and the ceramic fibers form evenly spaced peaks and valleys during the winding process; pressure release grooves are formed between the peaks and valleys; 5) coating the metal powder-doped silica composite interface material on the pressure release layer and fully covering the aerogel layer; wherein the metal powder-doped silica composite interface material forms a honeycomb pore structure for pressure release in the pressure release groove; 6) Insert two insulating plugs into the tube heads respectively so that the molybdenum wire inside the insulating plugs is connected to the conductive carbon paste coating.

10. The method for preparing a carbon-coated heating tube according to claim 9, characterized in that: The pressure release layer forms a 3-5° slope from the inside to the outside, and the pressure release groove is extended by the slope. When the silicon dioxide composite interface material doped with metal powder is filled in the pressure release groove, a honeycomb hole structure with an extended slope is formed; Silica composite interface materials doped with metal powder include: at least one metal powder for heat conduction; Aerogels doped with silica particles; Calculated by mass percentage, the silica particles account for 55-75% of the aerogel.

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