Accurate circulating temperature control heating device

Abstract

The invention discloses a precise circulating temperature control heating device, and particularly relates to the technical field of graphite heaters, the precise circulating temperature control heating device comprises a water cooling cavity and a water cooling cavity door movably connected with the water cooling cavity, an inner graphite heat preservation felt is mounted in the water cooling cavity, and an outer graphite heat preservation felt is mounted on the inner side wall of the water cooling cavity door; a copper electrode is installed on the outer wall of the water cooling cavity door, the inner end of the copper electrode penetrates through the water cooling cavity door and the outer graphite heat preservation felt, a graphite heater is installed at the end, located on the inner side of the outer graphite heat preservation felt, of the copper electrode, a sample groove for containing samples is formed in the graphite heater, and sawtooth gaps are formed in the sample groove at intervals. Through a special surface anti-oxidation treatment process for the heater, the heater can still work for a long time in an aerobic environment, a stable thermal field is provided, and the service life of the heater is greatly prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of graphite heaters, and more specifically, to a precise circulation temperature control heating device. Background Art

[0002] Currently available heating furnaces can generally heat materials, but the heating rate is low and cannot meet the needs of rapid heating up / down and long-term heat preservation at high temperatures.

[0003] With the development of science and technology, researchers are constantly exploring the heat treatment process of materials and have put forward higher requirements on the functions of test equipment, requiring the equipment to be able to achieve rapid temperature rise / lowering, long-term heating at 2000℃ or 2500℃, and various heating conditions in different atmospheres, vacuum environments, and aerobic environments. Summary of the invention

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a precise circulating temperature control and heating device, comprising a water-cooling cavity and a water-cooling cavity door movably connected to the water-cooling cavity, an inner graphite insulation felt is installed inside the water-cooling cavity, an outer graphite insulation felt is installed on the inner wall of the water-cooling cavity door, a copper electrode is installed on the outer wall of the water-cooling cavity door, the inner end of the copper electrode passes through the water-cooling cavity door and the outer graphite insulation felt, a graphite heater is installed at the end of the copper electrode located on the inner side of the outer graphite insulation felt, a sample slot for accommodating a sample is provided on the graphite heater, and a serrated gap is provided at intervals at the sample slot.

[0005] In a preferred embodiment, a thermal imaging water-cooling window assembly is installed on the top of the water-cooling cavity, a thermal imaging element is arranged above the thermal imaging water-cooling window assembly, and an infrared thermometer is arranged on the rear side of the water-cooling cavity.

[0006] In a preferred embodiment, the graphite heater is prepared by the following steps:

[0007] Step 1: bake the ordinary graphite heater with sawtooth gap in a baking oven at 300 degrees for 1 hour;

[0008] Step 2: wipe the surface of the graphite heater clean and put it into the anti-oxidation coating for sealing and soaking for 3 hours, then take it out and dry it naturally;

[0009] Step 3: After the graphite heater is dried, let it stand for 12 hours and then place it in a baking oven at 100 degrees Celsius for 1 hour;

[0010] Step 4: The dried graphite heater is sealed and immersed in a secondary anti-oxidation coating for 3 hours, taken out and dried naturally, and then left to stand for 12 hours;

[0011] Step 5: The dried graphite heater is sealed and immersed in a secondary anti-oxidation coating for 3 hours, taken out and naturally dried, and then left to stand for 12 hours to obtain a finished product.

[0012] In a preferred embodiment, the anti-oxidation coating is one of a penetrating graphite antioxidant, a graphite anti-oxidation coating or a boron nitride release spray.

[0013] Technical effects and advantages of the present invention:

[0014] 1. The present invention uses a special surface anti-oxidation treatment process for the heater, so that the heater can still work for a long time in an aerobic environment, providing a stable thermal field and greatly improving the service life of the heater;

[0015] 2. The present invention optimizes the design of the heater structure so that the heating device can reach a higher heating temperature and obtain a more stable and uniform thermal field area. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The invention discloses a square groove sawtooth graphite heater.

[0017] Figure 2 It is a square annular graphite heater of the present invention.

[0018] Figure 3 It is a common commercially available boat heater.

[0019] Figure 4 Schematic diagram of the graphite heater before heating.

[0020] Figure 5 Schematic diagram of carbonization after heating with a graphite heater.

[0021] Figure 6 This is a schematic diagram of a graphite heater after coating treatment according to the present invention.

[0022] Figure 7 This is a schematic diagram of a graphite heater treated with a coating according to the present invention after heating.

[0023] Figure 8 It is a schematic diagram of the overall structure of the present invention.

[0024] Fig. 9 It is another overall schematic diagram of the present invention from another angle.

[0025] The accompanying drawings are marked as: 1 water-cooling cavity, 2 water-cooling cavity door, 3 inner graphite insulation felt, 4 outer graphite insulation felt, 5 copper electrode, 6 graphite heater, 7 thermal imaging water-cooling window assembly, 8 thermal imaging element, 9 infrared thermometer. DETAILED DESCRIPTION

[0026] 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.

[0027] The present invention is a multifunctional sustainable heating laboratory equipment, which is widely used and can meet the needs of different fields and research. The heating device uses the Joule effect of the conductive material to perform precise temperature control heating, which can realize long-term heating of the material, or alternating temperature heating, and realize the needs of the scientific research field for material processing of different materials at continuous high temperature or alternating temperature.

[0028] like Figure 8-9 As shown, a precise circulation temperature control and heating device comprises a water-cooling cavity 1 and a water-cooling cavity door 2 movably connected to the water-cooling cavity 1, an inner graphite insulation felt 3 is installed inside the water-cooling cavity 1, an outer graphite insulation felt 4 is installed on the inner wall of the water-cooling cavity door 2, a copper electrode 5 is installed on the outer wall of the water-cooling cavity door 2, the inner end of the copper electrode 5 passes through the water-cooling cavity door 2 and the outer graphite insulation felt 4, a graphite heater 6 is installed at the end of the copper electrode 5 located on the inner side of the outer graphite insulation felt 4, a sample slot for accommodating a sample is provided on the graphite heater 6, and a serrated gap is provided at intervals at the sample slot.

[0029] Since most of the heaters on the market are boat-shaped, with a large cross-sectional area, their resistance is relatively small, and the maximum heating temperature can be heated to 2000°C. In addition, due to the thermal expansion of graphite, it is easy to be broken by heat at high temperatures. Figure 3 As shown;

[0030] The present invention optimizes the structure of the graphite heater 6. By optimizing the heater structure, the square groove structure is changed into a square groove sawtooth structure, so that the whole heating system is heated more evenly, the heating rate is faster, and the heating temperature is higher. Figure 1 As shown, compared with the boat-shaped heater of the same size, the sawtooth cross-sectional area is reduced and the effective length is increased, the overall resistance value of the heater is greatly improved, and the maximum heating temperature can reach 2500°C. At the same time, due to the tooth structure, the tooth gap of the heater can be compensated to a certain extent when it expands at high temperature, effectively avoiding the thermal expansion stress breakage of the heater at high temperature.

[0031] Furthermore, the square groove structure can be changed into a square ring structure, so that the whole heating system is heated more evenly, the heating rate is faster, and the heating temperature is higher, such as Figure 2 As shown;

[0032] Based on the above, the device effectively cools the water-cooled cavity 1 through the design of the water-cooled cavity 1, providing the heater with a stable and reliable closed heating environment for multiple working conditions such as vacuum / specific atmosphere / specific oxygen concentration. By directly heating the sample in the graphite heater 6 located in the water-cooled cavity 1, the heating rate can reach 40℃ / S, and the maximum temperature can reach 2500℃, which greatly improves the heating rate and maximum temperature. At the same time, the water-cooled cavity 1 adopts a hollow water-cooled structure, so that the graphite heater 6 can be cooled quickly, which provides favorable conditions for the temperature rise / fall alternating temperature test conditions.

[0033] The device is equipped with a mass flow meter, a vacuum system, and an online oxygen concentration detection device, which can achieve precise control of specific atmospheres such as nitrogen, argon and other gases, a vacuum environment with a vacuum degree below 5 Pa, and online oxygen concentration detection functions;

[0034] The graphite heater 6 inside the water-cooled cavity 1 is made of graphite. When the working temperature is below 1000°C, the graphite heater 6 in the cavity heats the sample. When the working temperature is below 1000-2000°C, graphite insulation felt is added inside the heating cavity to reduce power consumption and meet the heater's requirement of providing a stable thermal field.

[0035] A thermal imaging water-cooling window assembly 7 is installed on the top of the water-cooling cavity 1, a thermal imaging element 8 is arranged above the thermal imaging water-cooling window assembly 7, and an infrared thermometer 9 is arranged on the rear side of the water-cooling cavity 1 to monitor the actual temperature of the thermal field in the cavity and form a closed-loop control.

[0036] Based on the above, most common heating devices are closed, which makes it inconvenient to measure the temperature of the heated sample. Even if the temperature is measured, it is only measured at one point through a thermocouple or a thermometer. The present invention adds a thermal imaging function. Through the thermal imaging water-cooled window assembly 7, the thermal imaging equipment can monitor the heating conditions of the entire area of ​​the sample, and can directly observe and record the heating process of the sample more directly.

[0037] Furthermore, the working process of the present invention is: open the water-cooled chamber cover, place the sample in the graphite heater 6, or place the sample in a boron nitride (or other material) ark, and then place it in the graphite heater 6, close the water-cooled chamber door 2, and set the vacuum, specific atmosphere, etc. according to the specific working conditions to heat the sample. According to the set temperature control program, the graphite heater 6 is quickly heated after being powered on, wherein the water cooling system cools down the copper electrode 5, the water-cooled chamber 1, and the observation window for protection, and the infrared thermometer and the thermal imaging system monitor the heater temperature in real time to complete the heating treatment of the sample.

[0038] Based on the above, when the graphite heater 6 is heated in air, the graphite will produce a carbonization reaction when the temperature exceeds 400°C. According to experiments, when the graphite heater 6 is heated to 1100°C in air, the continuous heating time is about 2 hours and severe carbonization damage occurs, resulting in heater failure. Figure 4 and Figure 5 As shown;

[0039] Therefore, the graphite heater 6 is processed in the following steps:

[0040] Step 1: bake the common graphite heater 6 with sawtooth gap in a baking oven at 300 degrees for 1 hour;

[0041] Step 2: wipe the surface of the graphite heater 6 clean, put it into the anti-oxidation coating, seal it and soak it for 3 hours, then take it out and dry it naturally;

[0042] Step 3: After the graphite heater 6 is dried, let it stand for 12 hours and then place it in a baking oven at 100 degrees Celsius for 1 hour;

[0043] Step 4: The dried graphite heater 6 is sealed and immersed in a secondary anti-oxidation coating for 3 hours, taken out and dried naturally, and then left to stand for 12 hours;

[0044] Step 5: The dried graphite heater 6 is sealed and immersed in a secondary anti-oxidation coating for 3 hours, taken out and naturally dried, and then left to stand for 12 hours to obtain a finished product.

[0045] According to the graphite oxidation principle, a high-temperature resistant anti-oxidation coating is applied to the surface of the graphite heater 6 for surface anti-oxidation treatment, so that during the heating process, the graphite surface of the graphite heater 6 is isolated from the air due to the effect of the coating, thereby avoiding oxidation of the graphite heater 6 at high temperatures and increasing the service life of the heater.

[0046] When the graphite heater 6 treated with the anti-oxidation coating is heated to 1100°C in air, its service life increases from 2 hours to about 16 hours. Figure 6 , Figure 7 shown.

[0047] like Figure 7 As shown, the treated graphite heater 6 has been partially ablated and slightly deformed after heating, but has not been broken or damaged as a whole, which greatly improves the heating service life of the heater in the air.

[0048] Furthermore, the anti-oxidation coating is one of a penetrating graphite antioxidant, a graphite anti-oxidation coating or a boron nitride release spray;

[0049] Among them, the penetrating graphite antioxidant ZS-1052 graphite antioxidant adopts resin main chain melting technology. The cross-linked hydroxyl silicone fluorine resin main chain is evenly melted under high temperature and high pressure, and decomposed into nano-scale monomer resin. The modified resin can form a film alone, has a large number of functional groups, and has extremely strong permeability in graphite and good wrapping, which can effectively prevent oxides from contacting graphite and prevent graphite oxidation loss. It has an extremely low oxygen threshold, resistance to slag and high-temperature debris erosion and penetration erosion, and an oxygen diffusion rate of more than 96%. It prevents graphite oxidation corrosion and protects graphite from oxidation in high-temperature oxidizing atmospheres and molten liquids to extend its service life.

[0050] The graphite anti-oxidation coating is RLHY-305 graphite anti-oxidation coating, which is a high-temperature ceramic coating formed after polymerization reaction, high-temperature sintering and crushing. It can seal the graphite for oxidation resistance and corrosion resistance, and extend the life of graphite products.

[0051] The boron nitride release spray is JD-3028 boron nitride release spray, which can provide effective anti-oxidation protection for the graphite surface, prevent graphite oxidation loss, and protect the use of graphite in high temperature environment.

[0052] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0053] Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0054] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A precise circulation temperature control heating device, comprising a water-cooling cavity and a water-cooling cavity door movably connected to the water-cooling cavity, an inner graphite insulation felt is installed inside the water-cooling cavity, an outer graphite insulation felt is installed on the inner side wall of the water-cooling cavity door, a copper electrode is installed on the outer wall of the water-cooling cavity door, and the inner end of the copper electrode penetrates the water-cooling cavity door and the outer graphite insulation felt, characterized in that: A graphite heater is installed at the end of the copper electrode located on the inner side of the outer graphite insulation felt. A sample slot for accommodating the sample is arranged on the graphite heater, and sawtooth gaps arranged at intervals are arranged at the sample slot.

2. A precise cycle temperature control heating device according to claim 1, characterized in that: A thermal imaging water-cooling window assembly is installed on the top of the water-cooling cavity, a thermal imaging element is arranged above the thermal imaging water-cooling window assembly, and an infrared thermometer is arranged on the rear side of the water-cooling cavity.

3. The precise cycle temperature control heating device according to claim 1, characterized in that: The graphite heater is prepared by the following steps: Step 1: bake the ordinary graphite heater with sawtooth gap in a baking oven at 300 degrees for 1 hour; Step 2: wipe the surface of the graphite heater clean and put it into the anti-oxidation coating for sealing and soaking for 3 hours, then take it out and dry it naturally; Step 3: After the graphite heater is dried, let it stand for 12 hours and then place it in a baking oven at 100 degrees Celsius for 1 hour; Step 4: The dried graphite heater is sealed and immersed in a secondary anti-oxidation coating for 3 hours, taken out and dried naturally, and then left to stand for 12 hours; Step 5: The dried graphite heater is sealed and immersed in a secondary anti-oxidation coating for 3 hours, taken out and naturally dried, and then left to stand for 12 hours to obtain a finished product.

4. A precise cycle temperature control heating device according to claim 3, characterized in that: The anti-oxidation coating is one of a penetrating graphite antioxidant, a graphite anti-oxidation coating or a boron nitride release spray.

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