Tubular furnace capable of rapidly heating and cooling

Abstract

The invention discloses a rapid heating and cooling tubular furnace, and particularly relates to the technical field of tubular furnaces, the rapid heating and cooling tubular furnace comprises a vacuum cavity, a movably hinged water cooling cavity cover is arranged at the top of the vacuum cavity, a spiral cylindrical graphite heater is arranged in the vacuum cavity, and two sides of the bottom end of the vacuum cavity are respectively provided with a water cooling electrode; the water-cooled electrode penetrates through the vacuum cavity, extends upwards and sleeves two ends of the graphite heater, a sample tube is inserted into the graphite heater, two ends of the sample tube penetrate through the vacuum cavity and extend to two sides of the vacuum cavity, a sealing flange is arranged on the outer side of the end part of the sample tube, and a sample fixing rod is inserted into the sealing flange; the sample fixing rod penetrates through the sealing flange and the vacuum cavity and extends into the sample tube. According to the invention, the heating and cooling time can be shortened, the experiment efficiency is improved, the sample can rapidly reach a specific temperature interval, the method is suitable for sample treatment of different products in different temperature intervals, and byproducts are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of tube furnaces, and more particularly to a rapid temperature rise and fall tube furnace. Background Art

[0002] Tube furnace is a professional equipment for measuring the characteristics of materials under certain temperature and atmosphere conditions. It is suitable for heating treatment of various materials, such as heat treatment processes of metals, ceramics, oxides, etc. It is also used for quantitative analysis, such as sample pretreatment in chemical analysis and sintering experiments in material science. It is mainly used for experiments and small batch production in colleges and universities, scientific research institutes, industrial and mining enterprises, etc.

[0003] The existing tubular furnace uses resistance wire as the heat source, and the heating method is simple and convenient, but the disadvantage is that the heating speed is slow and the upper limit of the heating is low. The furnace uses high-purity alumina fiber, which has a good heat preservation effect, but it also reduces the cooling rate of the sample. The low upper temperature resistance of alumina fiber and the ability to not be severely thermally shocked also limit the upper limit of the heating of the tubular furnace and the heating and cooling speed. However, many experiments will have different products in different temperature zones. Therefore, if a specific temperature can be reached quickly or a certain high temperature can be reached quickly and then quickly dropped to a specific temperature, the reaction can be placed more in the desired temperature zone, so as to obtain the expected product faster and reduce by-products, thereby improving the accuracy of the experiment. Rapid heating and cooling can also improve the efficiency of the experiment, and provide significant help for the performance inspection of the sample under rapid temperature changes, shortening the length of the pyrolysis carbon chain, and reducing the agglomeration of catalyst crystal cells.

[0004] As can be seen from the above, although the existing tube furnace can be applied to most heating environments, it is no longer competent in processing environments that require a higher thermal field, and special occasions that require rapid temperature increase and decrease. It is necessary to design a device with a higher temperature increase limit and rapid temperature increase and decrease to meet experimental needs. Summary of the invention

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a rapid temperature rise and fall tubular furnace, comprising a vacuum cavity, a movable hinged water-cooled cavity cover is arranged on the top of the vacuum cavity, a spiral cylindrical graphite heater is arranged inside the vacuum cavity, a water-cooled electrode is installed on both sides of the bottom end of the vacuum cavity, the water-cooled electrode extends upward through the vacuum cavity and is sleeved on both ends of the graphite heater, a sample tube is inserted into the graphite heater, both ends of the sample tube extend through the vacuum cavity to both sides of the vacuum cavity, a sealing flange is arranged on the outside of the end of the sample tube, a sample fixing rod is inserted into the sealing flange, and the sample fixing rod extends through the sealing flange and the vacuum cavity to the inside of the sample tube.

[0006] In a preferred embodiment, the sealing flange includes an inner flange tube inserted on the outer wall of the vacuum chamber and an outer flange tube connected to the end of the inner flange tube, sealing rings are arranged at the ends of the inner flange tube and the outer flange tube where they are close to each other, and a vacuum clamp is arranged on the outside of the two sealing rings.

[0007] In a preferred embodiment, the end of the sample tube that passes through the outside of the vacuum chamber is inserted into the inside of the inner flange tube and the outer flange tube, the sample fixing rod passes through the outer flange tube and the inner flange tube in sequence and extends to the inside of the sample tube, and a sample pressing block is installed at the end of the sample fixing rod located inside the sample tube.

[0008] In a preferred embodiment, a lower graphite insulation felt is installed inside the vacuum chamber, the graphite heater is embedded inside the lower graphite insulation felt, and an upper graphite insulation felt is installed at the bottom of the water-cooled chamber cover.

[0009] In a preferred embodiment, when the water-cooling chamber cover is merged to the top of the vacuum chamber, the upper graphite insulation felt and the lower graphite insulation felt are embedded together.

[0010] In a preferred embodiment, locking hand wheels for locking the water-cooling chamber cover are installed on both sides of the top of the vacuum chamber.

[0011] In a preferred embodiment, a liquid nitrogen cooling device is installed on the top of the water-cooling chamber cover.

[0012] Technical effects and advantages of the present invention:

[0013] 1. The present invention can reduce the heating and cooling time, improve the experimental efficiency, make the sample quickly reach a specific temperature range, is suitable for processing samples with different products in different temperature ranges, and reduces by-products;

[0014] 2. The sample can be quickly heated and cooled to examine the performance changes of the sample under rapid temperature increase or decrease, or applied to other special occasions that require rapid temperature increase or decrease. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 It is a schematic diagram of the internal structure of the present invention;

[0017] Figure 3 For the present invention Figure 2 Schematic diagram of the detailed structure at point A in the middle.

[0018] The accompanying drawings are marked as follows: 1 vacuum chamber, 2 water-cooled chamber cover, 3 graphite heater, 4 sample tube, 5 sealing flange, 6 sample fixing rod, 7 inner flange tube, 8 outer flange tube, 9 sealing ring, 10 vacuum clamp, 11 sample pressing block, 12 lower graphite insulation felt, 13 upper graphite insulation felt, 14 locking hand wheel, 15 liquid nitrogen cooling device. DETAILED DESCRIPTION

[0019] 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.

[0020] Example 1

[0021] like Figure 1-3 A rapid temperature rise and fall tubular furnace shown in the figure comprises a vacuum chamber 1, a movable hinged water-cooled chamber cover 2 is arranged on the top of the vacuum chamber 1, a spiral cylindrical graphite heater 3 is arranged inside the vacuum chamber 1, the vacuum chamber 1 is made of stainless steel, and can provide a vacuum or atmosphere environment for the graphite heater 3, a water channel is built into the chamber wall, and cooling water is introduced for cooling, so that a lower surface temperature can be maintained during continuous high-temperature operation, the vacuum chamber 1 is provided with a temperature measuring window to detect the heater temperature, and the water-cooled chamber cover 2 is made of stainless steel, has a water channel and a liquid nitrogen channel inside, and has a sealing structure, which can be sealed with the vacuum chamber 1.

[0022] A water-cooled electrode is installed on both sides of the bottom of the vacuum chamber 1. The water-cooled electrode extends upward through the vacuum chamber 1 and is sleeved on both ends of the graphite heater 3. A sample tube 4 is inserted into the inside of the graphite heater 3. The water-cooled electrode is fixed on the vacuum chamber 1. There is a water channel in the water-cooled electrode, and it has a sealed and insulating structure. Cooling water can be passed through the water-cooled electrode to maintain a lower surface temperature during continuous high-temperature operation, and it is sealed and insulated with the vacuum chamber 1. The graphite heater 3 is fixed on the water-cooled electrode, adopts a spiral cylindrical structure, and uses the Joule heat principle, which has the characteristics of fast heating, high temperature, and uniform heating.

[0023] Both ends of the sample tube 4 penetrate the vacuum chamber 1 and extend to both sides of the vacuum chamber 1 . A sealing flange 5 is provided on the outer side of the end of the sample tube 4 . A sample fixing rod 6 is inserted into the sealing flange 5 . The sample fixing rod 6 penetrates the sealing flange 5 and the vacuum chamber 1 and extends to the interior of the sample tube 4 .

[0024] The sample tube 4 passes through the graphite heater 3 , the heated sample is placed in the sample tube 4 , both ends are sealed with sealing flanges 5 , and the position of the sample is fixed with a sample fixing rod 6 .

[0025] The sealing flange 5 includes an inner flange tube 7 inserted on the outer wall of the vacuum chamber 1 and an outer flange tube 8 connected to the end of the inner flange tube 7. Sealing rings 9 are arranged at the ends of the inner flange tube 7 and the outer flange tube 8 where they are close to each other, and a vacuum clamp 10 is sleeved on the outside of the two sealing rings 9.

[0026] like Figure 2 and Figure 3 As shown, the inner flange tube 7 of the sealing flange 5 is fixedly inserted on the cavity wall of the vacuum chamber 1, and is provided with two pieces, which are respectively located at the two ends of the sample tube 4, and an outer flange tube 8 is arranged on the outside. After the two flange tubes are butted at one end with a sealing ring 9, a vacuum clamp 10 is used to be sleeved and fixed to achieve rapid installation and sealing, and to achieve sealing with the sample tube 4, the vacuum chamber 1 and the sample fixing rod 6. At the same time, an air inlet, an air outlet, a pressure transmitter and a pressure reducing valve are installed on the sealing flange 5 to assist in air inlet and outlet and pressure reduction operations when the furnace body is heated.

[0027] The end of the sample tube 4 that passes through the outside of the vacuum chamber 1 is inserted into the inside of the inner flange tube 7 and the outer flange tube 8, and the sample fixing rod 6 passes through the outer flange tube 8 and the inner flange tube 7 in turn and extends to the inside of the sample tube 4. A sample pressing block 11 is installed at the end of the sample fixing rod 6 located inside the sample tube 4.

[0028] A lower graphite insulation felt 12 is installed inside the vacuum chamber 1, and the graphite heater 3 is embedded in the inner side of the lower graphite insulation felt 12. An upper graphite insulation felt 13 is installed at the bottom of the water-cooling chamber cover 2. When the water-cooling chamber cover 2 is merged to the top of the vacuum chamber 1, the upper graphite insulation felt 13 is embedded with the lower graphite insulation felt 12. The graphite insulation felt has the characteristics of high temperature resistance and good insulation effect.

[0029] Locking hand wheels 14 for locking the water-cooling chamber cover 2 are installed on both sides of the top of the vacuum chamber 1 . The locking hand wheels 14 are used to seal and lock the water-cooling chamber cover 2 on the top of the vacuum chamber 1 .

[0030] A liquid nitrogen cooling device 15 is installed on the top of the water-cooled chamber cover 2. The liquid nitrogen cooling device 15 can connect the inside of the vacuum chamber 1 with the liquid nitrogen pump, and is provided with a switch device and a stainless steel nozzle, which can spray liquid nitrogen on the graphite heater 3 and the sample tube 4 to achieve rapid cooling of the sample.

[0031] Based on the above, when in use, the sample is placed in the sample tube 4, and then the sample tube 4 is passed through the graphite heater 3, the two ends are sealed with sealing flanges 5, and a specific atmosphere is introduced into the sample, the sample fixing rod 6 is pushed to move along the sample tube 4, so that the sample pressing block 11 at the inner end of the sample fixing rod 6 pushes the sample to move, and the position of the sample is fixed by the sample fixing rod 6, the vacuum chamber 1 is evacuated to provide a vacuum environment for the graphite heater 3, the water cooling is turned on to maintain a low surface temperature of the equipment, the heating program is set, and the heating is started. After the heating is started, the power supply is energized to the graphite heater 3 through the water-cooled electrode. Due to the Joule heat principle, the temperature of the graphite heater 3 is rapidly increased. The high temperature resistance and thermal shock resistance of graphite can make the graphite heater 3 rise to a very high temperature at a very fast speed. The spiral cylindrical structure of the graphite heater 3 ensures the uniformity of the heating temperature, thereby providing a stable high temperature thermal field environment for the sample, and the vacuum chamber 1 provides a vacuum environment for the graphite heater 3 to prevent the graphite heater 3 from being oxidized at high temperature. The graphite insulation felt provides a thermal insulation effect to avoid heat loss, while also having the performance of high temperature resistance and thermal shock resistance. The water cooling effect of the vacuum chamber 1, the water-cooled chamber cover 2, and the water-cooled electrodes can maintain a lower surface temperature of the equipment when working at a continuous high temperature. The liquid nitrogen cooling device 15 can introduce liquid nitrogen after heating to achieve rapid cooling of the sample.

[0032] Example 2

[0033] Different from Example 1, the furnace is used for material sintering or metal smelting. When the sample is heated, it is first placed in a boron nitride crucible, and then the crucible is placed in a sample tube 4, specifically:

[0034] The sample to be melted is placed in a boron nitride crucible, and then the crucible is placed in a sample tube 4, the sample tube 4 is passed through a graphite heater 3, both ends are sealed with sealing flanges 5, and a specific atmosphere is introduced into the sample, the position of the sample is fixed with a sample fixing rod 6, the vacuum chamber 1 is evacuated, a vacuum environment is provided for the graphite heater 3, water cooling is turned on to maintain a low surface temperature of the equipment, the heating program is set and the heating is started, the graphite heater 3 can reach the set temperature in a very short time, and its maximum temperature can reach above 2000°C, which meets the requirements of material sintering or metal smelting. After reaching the set temperature, it can be kept warm for a long time to fully heat the sample, and liquid nitrogen is introduced after the heating is completed to achieve rapid cooling of the sample.

[0035] 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 can be mechanical connection or electrical connection, or the internal connection of two elements, or direct connection. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change;

[0036] 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;

[0037] 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 rapid temperature rise and fall tubular furnace, characterized in that: The utility model comprises a vacuum cavity, the top of which is provided with a movable hinged water-cooling cavity cover, the inside of which is provided with a spiral cylindrical graphite heater, a water-cooling electrode is installed on both sides of the bottom end of the vacuum cavity respectively, the water-cooling electrode penetrates the vacuum cavity, extends upward and is sleeved on both ends of the graphite heater, a sample tube is inserted into the inside of the graphite heater, both ends of the sample tube penetrate the vacuum cavity and extend to both sides of the vacuum cavity, a sealing flange is provided on the outer side of the end of the sample tube, a sample fixing rod is inserted into the sealing flange, the sample fixing rod penetrates the sealing flange and the vacuum cavity and extends to the inside of the sample tube.

2. The rapid temperature rise and fall tube furnace according to claim 1, characterized in that: The sealing flange comprises an inner flange tube plugged into the outer wall of the vacuum chamber and an outer flange tube butted against the end of the inner flange tube. Sealing rings are arranged at the ends of the inner flange tube and the outer flange tube where they are close to each other, and vacuum clamps are sleeved outside the two sealing rings.

3. The rapid temperature rise and fall tube furnace according to claim 2, characterized in that: The end of the sample tube that passes through the outside of the vacuum chamber is inserted into the inside of the inner flange tube and the outer flange tube, and the sample fixing rod passes through the outer flange tube and the inner flange tube in sequence and extends to the inside of the sample tube. A sample pressing block is installed at the end of the sample fixing rod located inside the sample tube.

4. The rapid temperature rise and fall tube furnace according to claim 3, characterized in that: A lower graphite insulation felt is installed inside the vacuum chamber, the graphite heater is embedded inside the lower graphite insulation felt, and an upper graphite insulation felt is installed at the bottom of the water-cooling chamber cover; When the water-cooling chamber cover is merged to the top of the vacuum chamber, the upper graphite thermal insulation felt and the lower graphite thermal insulation felt are embedded together.

5. The rapid temperature rise and fall tube furnace according to claim 1, characterized in that: Locking hand wheels for locking the water-cooling chamber cover are installed on both sides of the top of the vacuum chamber.

6. The rapid temperature rise and fall tube furnace according to claim 1, characterized in that: A liquid nitrogen cooling device is installed on the top of the water-cooling chamber cover.

Images