Carbon coating heating pipe and preparation method

Abstract

The invention relates to the technical field of carbon coating heating tubes, and discloses a carbon coating heating tube and a preparation method thereof, and the carbon coating heating tube comprises a quartz tube, two ends of the quartz tube are respectively provided with a tube head part used for electrode installation, and the inner wall of the quartz tube is coated with a conductive carbon paste coating; the end substrate is arranged on the inner wall of the pipe head, and the end substrate comprises a basic heat insulation layer and a pressure release layer; the basic heat insulation layer is formed by coating the head part of the pipe with an aerogel layer; a pressure release layer and an insulating plug are arranged outside the aerogel layer, an electrode is installed outside the insulating plug, and a molybdenum wire is arranged inside the insulating plug; the insulating plug is installed on the pipe head to seal the pipe head. The tube heads at the two ends of the quartz tube are coated with the aerogel layers for heat insulation, and meanwhile, the aerogel layers are externally provided with the pressure release layers formed by winding the ceramic fibers; when high pressure is generated in the quartz tube, the high pressure in the quartz tube can be released through the pressure release cavity.

Description

Technical Field

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

[0002] The structure of the traditional infrared heating tube basically includes a quartz tube, an insulating plug, an electrode and a heating wire; when the heating wire heats up inside the quartz tube, the quartz tube as a whole is in a heating state, and long-term use will cause the part in contact with the insulating plug to partially fall off or fall off as a whole, causing damage to the heating tube. Through a large number of tests, it was found that the occurrence of this phenomenon is related to the treatment process of the insulating plug and the quartz tube installation on the one hand, and on the other hand, when in use, the pressure inside the quartz tube increases with the increase of temperature, making the inside of the quartz tube in a high-pressure state, which accelerates the shedding of the contact part 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 object, the present invention provides a carbon coating 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, which is arranged on the inner wall of the pipe head, and comprises a basic heat insulation layer and a pressure release layer;

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

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

[0009] The 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 hole structure for pressure release in the pressure release groove;

[0010] An insulating plug, wherein the electrode is installed outside the insulating plug, and a molybdenum wire is arranged 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 comprises:

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

[0015] Aerogels doped with silica particles;

[0016] Among them, in terms of mass percentage, the proportion of silica particles in the aerogel is 55-75%.

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

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

[0019] Furthermore, the insulating plug comprises:

[0020] The insulating cover body is formed of ceramic material, and a plug body part for mounting with the tube head is arranged at the lower part of the insulating cover body, and a mounting groove for mounting the pole body is arranged inside the plug body part; a honeycomb plug is arranged along the inner wall of the mounting groove, and the honeycomb plug is arranged in a circular ring 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 at the upper part 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 installed 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 for heat insulation is coated inside the tube head;

[0028] 4) A pressure release layer formed by winding ceramic fibers is arranged outside the aerogel layer, and the ceramic fibers form convex peaks and concave valleys with uniform intervals during the winding process; and pressure release grooves are formed between the convex peaks and concave 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 hole 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 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;

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

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

[0034] Aerogels doped with silica particles;

[0035] Among them, in terms of mass percentage, the proportion of silica particles in the aerogel is 55-75%.

[0036] The present application is achieved by coating a layer of aerogel layer for heat insulation on the tube heads at both ends of a quartz tube, and at the same time providing 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, by coating a metal powder-doped silica composite interface material in a pressure release groove made of ceramic fibers, wherein the metal powder-doped silica composite interface material 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, the high pressure inside the quartz tube can be released 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 slurry coating instead of a heating wire, and coats the conductive carbon slurry coating on the inner wall of a quartz tube, thereby reducing thermal resistance, improving heat exchange efficiency and infrared conversion efficiency, extending the working life in a 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 diagram of the structure of the carbon coating heating tube in the present invention;

[0040] Figure 2 It is a schematic diagram of the structure of the insulating plug in the present invention;

[0041] Figure 3 It is a schematic diagram of the structure of the tube head in the present invention;

[0042] Figure 4 It is a schematic diagram of the connection between the molybdenum wire and the 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 slurry coating. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0045] Example 1

[0046] Reference Figure 1 to Figure 2 The present application proposes that the present invention provides a carbon coating heating tube, comprising:

[0047] A quartz tube 2, with tube heads 20 for mounting the electrodes 10 respectively disposed 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] The end head substrate is arranged on the inner wall of the pipe head 20, and the end head substrate includes a basic heat insulation layer 21 and a pressure release layer 22;

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

[0050] A pressure release layer 22 formed by winding ceramic fibers is arranged 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;

[0051] The 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 hole structure for pressure release in the pressure release groove;

[0052] An insulating plug 1, an electrode 10 is installed on the outside of the insulating plug 1, a molybdenum wire 16 is arranged inside the insulating plug 1, one end of the molybdenum wire 16 is connected to the electrode 10, and 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 for 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° inclined surface from the inside to the outside, and the pressure release groove is extended through the inclined surface. When the silica composite interface material doped with metal powder is filled in the pressure release groove, a honeycomb hole structure with an extended inclined surface is formed.

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

[0055] In the above, when the 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, the pressure release layer 22 is formed by winding ceramic fibers on a mold and then bonding them to the aerogel layer. It should be noted that the mold itself has a slope of 3-5°, and the mold has grooves formed by convex peaks and concave valleys. The ceramic fibers need to be adapted to the static pressure after winding, and the static pressure is not separated from the mold during static pressure.

[0057] In the above, the insulating plug 1 comprises: an insulating cover body 11 formed of ceramic material, a plug body part 12 for mounting with a tube head 20 is arranged at the lower part of the insulating cover body 11, and a mounting groove for mounting a pole body 15 is arranged on the inner side of the plug body part 12; a honeycomb plug 13 is arranged along the inner wall of the mounting groove, and the honeycomb plug 13 is arranged in a circular ring shape; a pole body 15 for fixing a molybdenum wire 16 is installed in the mounting groove, and a through hole for mounting the molybdenum wire 16 is arranged in the middle part of the pole body 15; and a notch 14 is opened along the outer wall of the pole body 15 at the upper part of the pole body 15, when the pole body 15 is installed in the mounting groove, the notch 14 contacts with the honeycomb plug 13, and the notch 14 is relatively closed to form a pressure release chamber. When the insulating plug 1 is installed to the tube head 20, the honeycomb hole structure for pressure release formed in the tube head 20 is arranged corresponding to the honeycomb plug 13.

[0058] The present application is to coat a layer of aerogel layer for heat insulation on the tube heads 20 at both ends of the quartz tube 2, and at the same time, a pressure release layer 22 formed by winding ceramic fibers is arranged outside the aerogel layer; on the one hand, the ceramic fibers have low thermal conductivity, and on the other hand, a metal-doped silica composite interface material is coated in the pressure release groove made of ceramic fibers, wherein the metal-doped silica composite interface material 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 2, the high pressure inside the quartz tube 2 can be released through the honeycomb hole 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 can effectively form two layers of heat insulation, so that the quartz tube 2 cannot directly apply heat to the contact part with the insulating plug 1 at the tube head 20, and at the same time, through effective pressure release, the insulating plug 1 and the quartz tube 2 installation part are effectively protected.

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

[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 peaks and valleys with uniform intervals during the winding process; and 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 hole structure for pressure release in the pressure release groove;

[0067] 6) Insert 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 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;

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

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

[0071] Aerogels doped with silica particles;

[0072] Among them, in terms of mass percentage, the proportion of silica particles in the aerogel is 55-75%.

[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, the metal powder-doped silica composite interface material includes: at least one metal powder for heat conduction; aerogel doped with silica particles; wherein, by mass percentage, the silica particles account for 55-75% of the aerogel. Furthermore, the metal powder is one or two of copper and tungsten. It should be noted that the aerogel in this application is silica aerogel.

[0075] In the above, when the 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, the pressure release layer 22 is formed by winding ceramic fibers on a mold and then bonding them to the aerogel layer. It should be noted that the mold itself has a slope of 3-5°, and the mold has grooves formed by convex peaks and concave valleys. The ceramic fibers need to be adapted to the static pressure after winding, and the static pressure is not separated from the mold during static pressure.

[0077] The present application is to coat a layer of aerogel layer for heat insulation on the tube heads 20 at both ends of the quartz tube 2, and at the same time, a pressure release layer 22 formed by winding ceramic fibers is arranged outside the aerogel layer; on the one hand, the ceramic fibers have low thermal conductivity, and on the other hand, a metal-doped silica composite interface material is coated in the pressure release groove made of ceramic fibers, wherein the metal-doped silica composite interface material 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 2, the high pressure inside the quartz tube 2 can be released through the honeycomb hole 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 can effectively form two layers of heat insulation, so that the quartz tube 2 cannot directly apply heat to the contact part with the insulating plug 1 at the tube head 20, and at the same time, through effective pressure release, the insulating plug 1 and the quartz tube 2 installation part are effectively protected.

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

[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] Although 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 the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Carbon coated heating tube, characterized in that, include: A quartz tube, wherein tube heads for electrode installation are respectively arranged at both ends of the quartz tube, and a conductive carbon slurry coating is coated on the inner wall of the quartz tube; An end head substrate, which is arranged on the inner wall of the pipe head, and comprises a basic heat insulation layer and a pressure release layer; The basic heat insulation layer is an aerogel layer for heat insulation coated on the pipe head; A pressure release layer formed by winding ceramic fibers is arranged outside the aerogel layer, and the ceramic fibers form peaks and valleys with uniform intervals during the winding process; and pressure release grooves are formed between the peaks and valleys; The 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 hole structure for pressure release in the pressure release groove; An insulating plug, wherein the electrode is installed outside the insulating plug, and a molybdenum wire is arranged 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 increases gradually 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 powders include: at least one metal powder for heat conduction; Aerogels doped with silica particles; Among them, in terms of mass percentage, the proportion of silica particles in the aerogel is 55-75%.

5. The carbon coating 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 bonding them 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 part for mounting with the tube head is arranged at the lower part of the insulating cover body, and a mounting groove for mounting the pole body is arranged inside the plug body part; a honeycomb plug is arranged along the inner wall of the mounting groove, and the honeycomb plug is arranged in a circular ring 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 at the upper part 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 for heat insulation is coated inside the tube head; 4) A pressure release layer formed by winding ceramic fibers is arranged outside the aerogel layer, and the ceramic fibers form peaks and valleys with uniform intervals during the winding process; and 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 hole 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 coating 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 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; Silica composite interface materials doped with metal powders include: at least one metal powder for heat conduction; Aerogels doped with silica particles; Among them, in terms of mass percentage, the proportion of silica particles in the aerogel is 55-75%.

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