High-temperature liquid molten salt variable-thickness packaging heating furnace for laser flashing method

Abstract

The utility model discloses a variable-thickness packaging heating furnace for high-temperature liquid molten salt, which belongs to the technical field of heating furnaces and is provided with a water-cooling metal shell, a gas inlet and a gas outlet, a heat-insulating layer and an upper heat-insulating plate are arranged in the heating furnace, and a metal soaking furnace body is arranged in the heat-insulating layer. The metal soaking pit furnace body is provided with a heating element, the center furnace body is arranged in the center of the metal soaking pit furnace body, the center furnace body is provided with a thermocouple, the crucible is arranged in the center, the center furnace body, the outer crucible, the inner crucible and the crucible cover are matched through a notch, a clamping groove and a flange, and the flange at the upper end of the inner crucible is matched with a heat insulation block, a clamping block and an adapter. The protective atmosphere is achieved by adopting the closed cavity design, heat dissipation between the upper surface and the lower surface of the crucible and the environment is reduced through the design of the heat preservation component and the design of the size of the heating cavity, and it is ensured that the temperature of the outer wall face of the heating furnace is within a safe range through the design of the water-cooling metal shell.

Description

TECHNICAL FIELD

[0001] The utility model belongs to heating furnace technical field, especially relate to a kind of high-temperature liquid molten salt variable thickness packaging heating furnace for laser flash method, for the thermal diffusivity of high-temperature liquid molten salt measured by laser flash method. BACKGROUND

[0002] The existing laser flash method measurement is limited to measuring optically transparent or opaque objects, and for semi-transparent objects at high temperature, the thermal conductivity obtained by fitting the measurement data has significant deviation between the influence of thermal radiation and the true value, and the thermal conductivity obtained under different measurement conditions has significant discreteness. The existing measurement means lacks sufficient information to quantify the influence of thermal radiation on thermal conductivity measurement.

[0003] The upper end cover of the crucible in the device mentioned in Chinese invention patent CN115825145B high-temperature liquid molten salt thermal radiation and thermal parameter combined measurement device and inversion method is directly contacted with the atmospheric environment, and the convective heat transfer at the wall surface affects the temperature measurement accuracy. In addition, the device lacks a protective atmosphere, and at high temperature, metal, molten salt vapor and corrosion-resistant coating may react with oxygen, thereby affecting the accuracy of measurement, the safety and service life of the system. In addition, the high-temperature parts of the device are exposed, and there is a high-temperature wall, which increases the operation risk. UTILITY MODEL CONTENT

[0004] Therefore, in order to solve the problems of convective heat transfer with the outside world, lack of protective atmosphere and high-temperature wall exposure, the utility model provides a high-temperature liquid molten salt variable thickness packaging heating furnace for laser flash method, which adopts a closed cavity design to realize a protective atmosphere, reduces the heat dissipation of the upper and lower surfaces of the crucible through the design of the heat preservation component and the size of the heating cavity, and ensures that the temperature of the outer wall of the heating furnace is within a safe range through the design of the water-cooled metal shell.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme: a high-temperature liquid molten salt variable thickness packaging heating furnace for laser flash method, comprising an outer shell, a metal soaking furnace body and a center furnace body, a thermocouple is placed in the center furnace body, the center furnace body is sleeved with a metal soaking furnace body, the metal soaking furnace body can be heated, the center furnace body and the metal soaking furnace body are located in the outer shell, and a crucible is placed in the center furnace body.

[0006] An upper end cylinder cover is installed above the outer shell, an upper end cover is installed on the upper end cylinder cover, a protective gas inlet A and a protective gas outlet B are arranged on the upper end cover for the inlet and outlet of protective gas, an optical window one is arranged at the center of the upper end cover, and an optical window two is arranged at the center of the bottom of the outer shell.

[0007] Further, the outer shell is provided with a heat preservation structure between the center furnace body and the metal soaking furnace body.

[0008] Further, the outer shell comprises a lower water cooling disc, a metal shell and an upper water cooling disc, the upper water cooling disc is installed above the metal shell, and the lower water cooling disc is installed below the metal shell.

[0009] Further, an upper end cylinder cover is installed above the outer shell, an upper end cover is installed on the upper end cylinder cover, and a protective gas inlet A and a protective gas outlet B are arranged on the upper end cover for the inlet and outlet of the protective gas.

[0010] Further, a diaphragm is arranged on the optical window one.

[0011] Further, the optical window two is arranged in the center of the lower water cooling disc.

[0012] Further, the crucible comprises an outer crucible, an inner crucible and a crucible cover, the outer crucible is provided with a gas permeable hole in the circumferential direction, an upper end face is designed with a flange for radial fixation, and a clamping groove is designed for assembly with the crucible cover to ensure the constraint of the crucible cover in the direction of gravity.

[0013] Further, the upper end of the inner crucible has a flange structure, which is assembled with a clamping block, a heat insulation block and an adapter, and the clamping block and the adapter are mechanically assembled through the cooperation of threads and screws.

[0014] Further, the adapter is connected with a ball screw, so that the adapter and the inner crucible are lifted through the ball screw, and the thickness of the molten salt between the lower end face of the inner crucible and the lower end face of the outer crucible is changed.

[0015] Further, the metal soaking furnace body is internally provided with a heating rod or an externally wound heating wire.

[0016] Compared with the prior art, the high-temperature liquid molten salt variable thickness packaging heating furnace for the laser flash method has the beneficial effects that:

[0017] 1. The upper end inner wall of the existing inner crucible for loading high-temperature liquid molten salt is exposed to the gas environment, so there is obvious heat loss. The present application reduces the direct contact of the upper end inner wall of the inner crucible with the gas by designing a heat insulation block, effectively reduces the convective heat transfer between the crucible and the surrounding gas, and further reduces the temperature measurement uncertainty.

[0018] 2. The present application realizes the protective atmosphere in the furnace body through the closed design, can effectively eliminate the reaction of the metal furnace body, the corrosion-resistant coating and the molten salt vapor and oxygen, and improve the safety and service life of the system.

[0019] 3. The utility model discloses a water cooling element is added, has guaranteed that the device whole's external surface does not exist high temperature surface, improved the operation safety. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings constituting a part of the utility model are used to provide further understanding on the utility model, and the illustrative embodiment of the utility model and its explanation are used to explain the utility model, and do not constitute improper limitation on the utility model.

[0021] Figure 1 The structure schematic diagram of high temperature liquid molten salt variable thickness packaging heating furnace for laser flash method for the utility model discloses;

[0022] Figure 2 It is the section view of outer crucible;

[0023] Figure 3 It is the front view of outer crucible;

[0024] Figure 4 It is the top view of outer crucible;

[0025] Figure 5 It is the assembly schematic diagram of adapter and ball screw;

[0026] Figure 6 It is the front view section schematic diagram of example 2.

[0027] In the drawing: 1 - lower water cooling disc, 2 - heat preservation layer, 3 - metal shell, 4 - metal muffle body, 5 - center furnace body, 6 - heating rod, 7 - heating rod head, 8 - upper end cylinder cover, 9 - upper end sealing cover, 10 - thermocouple one, 11 - adapter, 12 - optical window one, 13 - wiring hole, 14 - thermocouple two, 15 - water cooling flow channel, 16 - upper water cooling disc, 17 - upper heat preservation plate, 18 - heat insulation block, 19 - inner crucible, 20 - clamp block, 21 - crucible cover, 22 - liquid molten salt, 23 - outer crucible, 24 - optical window two, 25 - clamping groove, 26 - air hole, 27 - flange, 28 - ball screw, 29 - heating ring. DETAILED DESCRIPTION

[0028] The technical scheme in the embodiment of the utility model will be clearly and completely set forth in combination with the drawings in the embodiment of the utility model. It should be noted that the embodiment in the utility model and the features in the embodiment can be combined mutually in the case of no conflict, and the described embodiment is only a part of the embodiment of the utility model, not all the embodiment.

[0029] Referring to Figures 1-6The embodiment is a high-temperature liquid molten salt variable thickness package heating furnace for laser flash method, which comprises an outer shell, a metal soaking furnace body 4 and a center furnace body 5, the center furnace body 5 is provided with a thermocouple, the metal soaking furnace body 4 is sleeved on the outer periphery of the center furnace body 5, the metal soaking furnace body 4 can be heated, the center furnace body 5 and the metal soaking furnace body 4 are located in the outer shell, and a crucible is arranged in the center furnace body 5.

[0030] An upper end cylinder cover 8 is arranged on the upper side of the outer shell, an upper end cover 9 is arranged on the upper end cylinder cover 8, a protective gas inlet A and a protective gas outlet B are arranged on the upper end cover 9, and the protective gas inlet A and the protective gas outlet B are used for the inlet and outlet of the protective gas, and an optical window one 12 is arranged at the center of the upper end cover 9, and an optical window two 24 is arranged at the center of the bottom of the outer shell.

[0031] The upper water cooling disc 16, the lower water cooling disc 1, the metal outer shell 3, the upper end cylinder cover 8 and the upper end cover 9 form the outer shell of the heating furnace, and are all made of strong heat-conducting metal or metal alloy, and the safety of the outer wall surface temperature is realized through the water cooling flow channel 15.

[0032] The upper water cooling disc 16 and the lower water cooling disc 1 both have water cooling pipes, the upper water cooling disc 16 is circumferentially opened for placing the heating rod 6, and is centrally opened for placing the crucible, the lower water cooling disc 1 is centrally perforated for the laser light path to pass through, the metal outer shell 3 is in a cylindrical shape, the heat preservation layer 2 is provided with a non-through circular hole with the same outer diameter as the metal soaking furnace body 4 from the upper end surface to the lower end surface, and is used for reducing the heat conduction of the metal soaking furnace body 4 and the water cooling disc and the metal outer shell 3.

[0033] The metal soaking furnace body 4 is used for receiving the heat of the heating rod 6 and plays a role of uniformly conducting heat to the center, a plurality of heating rods 6 are uniformly arranged in the circumferential direction of the metal soaking furnace body 4, and the heat generated by heating is uniformly conducted to the center furnace body 5 after passing through a certain heat conduction thickness of the metal soaking furnace body, so that the uniformity of the temperature in the heating furnace is ensured.

[0034] The upper water cooling disc 16 and the lower water cooling disc 1 are respectively placed and fixed on the upper and lower end surfaces of the metal outer shell 3, the heat preservation layer 2 is placed on the upper end surface of the lower water cooling disc 1, the metal soaking furnace body 4 is placed in the circular hole of the heat preservation layer 2, the heating rod 6 is placed in the circumferential slot hole of the metal soaking furnace body 4, the center furnace body 5 is placed in the central slot hole, the crucible is placed in the central slot hole of the center furnace body 5, the upper heat preservation plate 17 is placed above the metal soaking furnace body 5, the upper end cylinder cover 8 is placed on the upper end surface of the upper water cooling disc 16, and the upper end cover 9 is placed on the upper end surface of the upper end cylinder cover 8. The heat preservation layer 2 has a temperature resistance effect of 1600 DEG C.

[0035] The upper heat insulation plate 17 is provided with a circumferential hole for placing the heating rod 6 and a central hole for placing the central furnace body 5. The metal soaking furnace body 4 is provided with a circumferential groove for placing the heating rod 6, a central hole for placing the central furnace body 5, and a laser light path, and the central furnace body 5 is provided with a central hole for placing and extracting the crucible. The heating rod 6 is used for heating the metal soaking furnace body 4, and the circumferential hole of the crucible is used for steam discharge.

[0036] The upper end cylinder cover 8 and the upper end sealing cover 9 are used for sealing the furnace body and introducing the protective gas, and the lower end optical window 24 is used for sealing the furnace body.

[0037] The upper end sealing cover 9 is provided with a protective gas inlet A and a protective gas outlet B for introducing and discharging the protective gas, and is provided with an optical window 12 at the center for the infrared radiation of the upper surface of the inner crucible 19 to pass through and play a sealing role.

[0038] The protective gas inlet and outlet are two pneumatic joints of the upper end sealing cover 9, one of which is used for introducing the protective gas, and the other is used for discharging the gas.

[0039] The lower water cooling disc 1 is provided with an optical window 24 at the center for the excitation laser to pass through and play a sealing role.

[0040] The upper end cylinder cover 8 is provided with a wire hole in the side wall, which is used for leading out the lead wires of the heating rod 6 and the thermocouple.

[0041] The heat insulation layer 2 and the upper heat insulation plate 17 are used for heat insulation between the metal soaking furnace body 4 and the central furnace body 5 and the upper water cooling disc 16, the lower water cooling disc 1, the gas environment and the metal shell 3.

[0042] The upper heat insulation plate 17 is provided with a notch to facilitate the placement of the heating rod 6.

[0043] The heating rod head 7 is the packaging head of the lead wire of the heating rod. The central furnace body 5 plays a role of receiving heat, further homogenizing temperature, quickly extracting the crucible and measuring temperature. The heat of the metal soaking furnace body 4 is transmitted to the crucible after being transmitted to the central furnace body 5. The central furnace body 5 is loaded with the crucible, which can be quickly and integrally extracted by extracting the central furnace body 5. The central furnace body 5 is provided with a hole groove structure at the center and is divided into two parts: the upper part has a large hole diameter, the hole opening of which is transitionally matched with the flange part of the outer crucible 23 to ensure the concentricity of the outer crucible 23 and the central hole; the lower part has a small hole diameter and is used for bearing the outer crucible 23 and the excitation laser to pass through.

[0044] Two thermocouples are arranged in the circumferential direction of the central furnace body 5, namely thermocouple one 10 and thermocouple two 14, the temperature measurement result of thermocouple two 14 is used as the PID temperature control input of the heating rod 6, the temperature measurement results of the thermocouples 10 and 14 are compared, and the temperature uniformity of the high-temperature liquid molten salt is evaluated, and since the molten salt is not directly contacted, the corrosion risk of the thermocouple and the error caused by corrosion are avoided.

[0045] The outer crucible 23, the inner crucible 19 and the crucible cover 21 form a packaging container of the high-temperature liquid molten salt, that is, a crucible, the outer crucible 23 is provided with a gas hole 26 in the circumferential direction, which is used to exhaust the steam generated during the phase change of the molten salt and balance the internal and external pressures, and is provided with a flange 27 at the upper end surface for radial fixation, and is provided with a clamping groove 25 for assembly with the crucible cover 21 to ensure the constraint of the crucible cover 21 in the direction of gravity. The upper end of the inner crucible 19 has a flange structure, which is assembled with the clamp block 20, the heat insulation block 18 and the adapter 11, the clamp block 20 and the adapter 11 are mechanically assembled through the cooperation of threads and screws, the adapter 11 is connected with the ball screw, and the molten salt thickness between the lower end surface of the inner crucible 19 and the lower end surface of the outer crucible 23 is changed by lifting the adapter 11 through the ball screw.

[0046] The extension arm of the adapter 11 is connected with the ball screw, the adapter 11 is used to connect the crucible and the ball screw, the up-down movement of the ball screw drives the up-down movement of the adapter 11, and finally realizes the up-down movement of the crucible. The crucible upper end flange and the adapter 11 clamp the heat insulation block 18 through screw connection, and the heat insulation block 18 is used to reduce the heat conduction of the crucible and the adapter 11. The head of the adapter 11 outside the furnace body can be designed in different types of matching mode, and the assembly with the ball screw can complete the function.

[0047] The clamp block 20 and the adapter 11 are both metal materials, the flange part of the heat insulation block 18 plays a heat insulation role between the clamp block 20 and the adapter 11, and the central cylinder part of the heat insulation block 18 plays a heat insulation role between the inner crucible 19 and the gas environment.

[0048] Example 1:

[0049] The structure of the metal soaking furnace body 4 can be changed, and the way of inserting the heating rod 6 in the circumferential direction is changed to the way of winding the heating wire in the circumferential direction, so that the installation of the heating element is facilitated, the uniform heating effect is improved, and the size of the metal soaking furnace body 4 is reduced. In addition, since the upper and lower end faces of the metal soaking furnace body 4 are close to the water-cooled disc, the temperature of the upper and lower end faces is relatively lower than that of the central part, the heating wire can be segmented, the upper and lower distribution of the heating wire is adopted, the power distribution of each heating wire is adjusted, and the uniformity of the temperature is further improved. The planar spiral heating wire can also be placed on the upper and lower end faces of the metal soaking furnace body 4, and the temperature uniformity is further improved through heating at the upper and lower end faces.

[0050] Embodiment 2:

[0051] The optical window 24 can be replaced by a zoom component, and an internal thread is added at the central hole of the lower water-cooled disc 1, and the zoom component is connected through the thread at this position, so that the functions of sealing and focusing are realized. The lower water-cooled disc 1 can be extended at the central hole of the lower end face to a certain length to cooperate with the up-down movement of the zoom component, and the zoom component changes the spot size of the excitation laser irradiated to the lower end face of the outer crucible 23 through the up-down movement. By changing the size of the spot, the heat transfer mechanism inside the liquid molten salt is expanded from one-dimensional approximation to three-dimensional. When the laser uniformly and completely irradiates to the lower end face of the outer crucible 23, the heat transfer inside the liquid molten salt is approximately one-dimensional heat transfer; when the laser spot size is smaller than the lower end face of the outer crucible 23 or the laser energy distribution is uneven, the three-dimensional effect of the heat transfer inside the liquid molten salt is significant.

[0052] Embodiment 3:

[0053] A diaphragm can be added above the optical window 12, and the diaphragm can adopt the form of a central opening and a ring-shaped opening, so that the selective temperature measurement of the upper end face of the inner crucible 19 is realized. The temperature measurement area corresponding to the central opening diaphragm is the central spot of the upper end face of the inner crucible 19, and the temperature measurement area corresponding to the ring-shaped opening diaphragm is the ring of the upper end face of the inner crucible 19. In combination with the adjustment of the spot size in Embodiment 3, the three-dimensional heat transfer mechanism in the molten salt is significant, different temperature measurement areas correspond to the radiation heat transfer under different optical thicknesses, and therefore more effective temperature information can be obtained.

[0054] The above disclosed embodiments of the utility model are only used for helping to set forth the utility model. The embodiments do not describe all the details, and also do not limit the utility model to the specific implementation mode. According to the content of the specification, many modifications and changes can be made. The specification selects and specifically describes these embodiments, in order to better explain the principle and practical application of the utility model, so that the person skilled in the art can well understand and utilize the utility model.

Claims

1. A high temperature liquid molten salt variable thickness package furnace for laser flash method, characterized in that: It comprises a shell, a metal soaking furnace body (4) and a center furnace body (5) in which a thermocouple is placed, the metal soaking furnace body (4) can be heated, the center furnace body (5) and the metal soaking furnace body (4) are located in the shell, and a crucible is placed in the center furnace body (5); An upper end cylinder cover (8) is installed above the shell, an upper end cover (9) is installed on the upper end cylinder cover (8), a protective gas inlet A and a protective gas outlet B are arranged on the upper end cover (9) for the inlet and outlet of protective gas, an optical window one (12) is arranged at the center of the upper end cover (9), and an optical window two (24) is arranged at the center of the bottom of the shell.

2. The high temperature liquid molten salt variable thickness package heating furnace for laser flash method according to claim 1, characterized in that: A heat preservation structure is arranged between the shell and the center furnace body (5) and the metal soaking furnace body (4).

3. The high temperature liquid molten salt variable thickness package heating furnace for laser flash method according to claim 1, characterized in that: The shell comprises a lower water cooling disc (1), a metal shell (3) and an upper water cooling disc (16), the upper water cooling disc (16) is installed above the metal shell (3), and the lower water cooling disc (1) is installed below the metal shell (3).

4. The high temperature liquid molten salt variable thickness package heating furnace for laser flash method according to claim 3, characterized in that: The optical window two (24) is arranged at the center of the lower water cooling disc (1).

5. The high temperature liquid molten salt variable thickness package heating furnace for laser flash method according to claim 1, characterized in that: An aperture is arranged on the optical window one (12).

6. The high temperature liquid molten salt variable thickness package heating furnace for laser flash method of claim 1, wherein: The crucible comprises an outer crucible (23), an inner crucible (19) and a crucible cover (21), air holes (26) are arranged in the circumferential direction of the outer crucible (23), a flange (27) is designed on the upper end face for radial fixation, and a clamping groove (25) is designed for assembly with the crucible cover (21) to ensure the constraint of the crucible cover (21) in the direction of gravity.

7. The high temperature liquid molten salt variable thickness package heating furnace for laser flash method according to claim 6, characterized in that: The upper end of the inner crucible (19) has a flange structure, and is assembled with a clamping block (20), a heat insulation block (18) and an adapter (11), the clamping block (20) and the adapter (11) are mechanically assembled through the cooperation of threads and screws.

8. The high temperature liquid molten salt variable thickness package heating furnace for laser flash method according to claim 7, characterized in that: The adapter (11) is connected with a ball screw, so that the adapter (11) and the inner crucible (19) are lifted through the ball screw, and the thickness of the molten salt between the lower end face of the inner crucible (19) and the lower end face of the outer crucible (23) is changed.

9. The high temperature liquid molten salt variable thickness package heating furnace for laser flash method of claim 1, wherein: The metal soaking furnace body (4) is internally installed with a heating rod (6) or externally wound with a heating wire.

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