Air suspension laser heating furnace for neutron scattering

Abstract

The utility model discloses an air suspension laser heating furnace for neutron scattering, which comprises a furnace chamber, a mounting platform and a base, a positioning laser, a first CCD (charge coupled device) camera and an optical position sensor are arranged on the mounting platform, and the positioning laser and the optical position sensor are matched with each other and are used for monitoring the suspension height of a sample in real time; an upper cover is arranged between the furnace chamber and the mounting platform, a heating laser, an infrared thermometer and a second CCD camera which penetrate through the upper cover are arranged at the upper end of the upper cover, and the second CCD camera is used for observing the state change of the surface of the sample; a suspension platform, a nozzle arranged on the upper end face of the suspension platform and an airflow system connected with the nozzle are arranged in the furnace chamber, the nozzle comprises a nozzle opening, and a plurality of capillary grooves are formed in the peripheral side of the nozzle opening; the airflow system is used for conveying airflow for suspension; and the nozzle is used for spraying out gas and suspended materials. According to the utility model, suspension heating is realized, and the heating temperature of 3000K can be provided for different material samples with the diameter of 3mm.

Description

TECHNICAL FIELD

[0001] The utility model relates to neutron scattering technical field especially is related to a kind of for neutron scattering's gas suspension laser heating furnace. BACKGROUND

[0002] Due to the strong penetration of neutrons, no charge, and interaction with other particles, the internal structure and dynamics of atomic nuclei can be studied by neutron scattering. It can be used to study the active sites and reaction mechanism of catalysts. Neutron diffraction technology can be used to determine the precise three-dimensional structure of molecules. Therefore, neutron scattering technology is a detection and analysis tool for studying the static structure and dynamic process of matter at atomic and molecular scales.

[0003] The existing heating furnace for neutron scattering experiment mainly has induction heating, laser heating and metal foil element heating:

[0004] Neutron scattering induction heating device, induction heating is to use electromagnetic induction principle to heat conductive materials, its heating material is limited to metal materials, and its maximum use temperature does not exceed 1500℃, with certain limitations;

[0005] Neutron scattering metal foil element heating, metal foil heating element will be seriously worn in high temperature for a long time, so the metal foil element high temperature furnace usually provides 1600℃ high temperature experimental environment for neutron scattering experimental sample;

[0006] Ordinary neutron scattering laser heating high temperature furnace, laser heating furnace mainly irradiates experimental sample connected with sample rod by high-power laser, because the higher the sample temperature, the greater the power of the energy radiated to the outside of the surface, and the larger the diameter of the sample, when the temperature is above 1000℃, the surface scatters a large amount of heat to the outside. On the other hand, the sample is in direct contact with the sample rod, and the heat loss through the sample rod is the main factor restricting the sample temperature, which cannot provide a sample environment above 1500℃.

[0007] For sample environment heating furnace providing above 1600℃, there are mainly two schemes based on electrostatic suspension and aerodynamic suspension. After suspension, the sample is in a container-free state, which can easily heat the sample to above 2000℃. Electrostatic suspension is usually used to suspend conductors or semiconductors, which uses charged samples in an electric field to achieve suspension by Coulomb force, same repulsion and different repulsion. Although the electrostatic suspension laser heating furnace can increase the sample temperature to as high as 3000℃, the electrostatic suspension system is relatively complex, the voltage between electrodes has the risk of breakdown, and the surface charge of the sample will run off during heating, which needs to be supplemented by ultraviolet lamp, but the effect is not very obvious. It is difficult to control the suspension stability of the sample during heating, and the sample needs to be accurately controlled in horizontal and vertical direction during suspension, so the control system is complex, and a lot of time is needed for system parameter debugging The utility model discloses a content

[0008] Therefore, the utility model discloses a purpose to provide a kind of for neutron scattering's gas suspension laser heating furnace, realize suspension heating, can provide 3000K heating temperature for different material sample.

[0009] The utility model discloses a purpose is realized by the following technical scheme:

[0010] A kind of for neutron scattering's gas suspension laser heating furnace, including furnace cavity, installation platform being set to the upper end of furnace cavity, and pedestal being set to the lower end of furnace cavity, the installation platform is provided with positioning laser, first CCD camera and optical position sensor, the positioning laser and optical position sensor cooperate with each other, for real-time monitoring the suspension height of sample;

[0011] The furnace cavity and the installation platform between still be provided with upper cover, the upper end of the upper cover is provided with the heating laser that penetrates the upper cover, infrared thermometer and second CCD camera, the second CCD camera is used to observe the state change of sample surface;

[0012] The furnace cavity is provided with suspension platform, nozzle being set to the upper end of the suspension platform, and airflow system being connected with the nozzle, the nozzle includes nozzle mouth, and the periphery of the nozzle mouth is provided with a plurality of capillary grooves;The airflow system is used to transport suspension airflow;The nozzle is used to spray gas and suspend material.

[0013] Further, the second CCD camera and the nozzle mouth axis angle are 20 °.

[0014] Further, the nozzle also includes lower cavity and steady flow chamber, the nozzle mouth is connected with the lower cavity by constriction neck, the steady flow chamber is connected to the lower end of the lower cavity, the nozzle mouth is the conical cavity with bottom surface upward, and the lower cavity is the conical cavity with bottom surface downward.

[0015] Further, the airflow system includes air inlet pipeline and air outlet port, the air inlet pipeline is connected to the lower end of steady flow chamber, and the air outlet port is arranged on the upper cover.

[0016] Further, the furnace cavity is provided with air channel interface for connecting with air inlet pipeline.

[0017] Further, the furnace cavity is also provided with cooling system, and the cooling system includes water inlet pipeline, cooling water flow channel, water cooling cavity and water outlet pipeline, the water inlet pipeline and water outlet pipeline are communicated with the water cooling cavity by the cooling water flow channel, and the water cooling cavity is annularly arranged on the outer periphery of the nozzle and exchanges heat with the nozzle.

[0018] Further, a waterway interface is arranged on the furnace cavity and connected with the water inlet pipeline and the water outlet pipeline.

[0019] Further, a neutron incident window, a neutron emission window, a neutron scattering window, an optical window and a sample transfer window are arranged on the furnace cavity.

[0020] Further, a reflecting device matched with the optical window is arranged on the base.

[0021] Further, the heating laser adopts a 200W single-beam laser, and the laser spot diameter is 1.5mm.

[0022] The utility model avoids the direct contact of sample and container, reduces the sample heat scattering at high temperature, and the utility model can heat any material sample, realize the heating of sample from solid to molten state, and the utility model can heat the sample with 3mm diameter to 3000K. The utility model can observe the sample surface state change at any time in the heating process through the camera, and can observe the laser irradiation and infrared temperature detector detection position through the camera, and the experimental operation efficiency is improved. The utility model designs the nozzle with water cooling cavity, can avoid the nozzle port large temperature rise in the heating process, causes the deformation of gas flow channel, and affects the stability of sample suspension.

[0023] The key point of the utility model is based on the pneumatic suspension principle and cooperates with laser heating, realizes the container-free heating, avoids the contact and heat conduction of sample and other components, and can heat the sample to 3000K neutron scattering laser heating furnace. In the utility model, a 200W laser is vertically irradiated to the sample to avoid the uneven heating of the sample surface and cause disturbance. The cooling cavity is arranged between the nozzle and the suspension platform, the structure is simple, the nozzle can be directly cooled, and the deformation caused by overheating of the nozzle is avoided. Three capillary grooves are arranged on the nozzle port, a small amount of gas is allowed to flow out from the capillary grooves around the bottom of the sample when the sample does not jump, the upward acceleration of the sample in the suspension instant can be reduced, and the stability of the sample suspension jump can be increased.

[0024] The principle of the utility model is to use the kinetic energy of high-speed gas to offset the gravitational potential energy of the sample, realize the suspension of the heated sample, and use laser irradiation to heat the sample in the suspension. The utility model utilizes the conical nozzle to guide the airflow to uniformly flow around the sample. Once the sample deviates from the center position of the nozzle in the suspension, the sample automatically returns to the center position due to the uneven gas flow on the sample surface, so that the sample does not have horizontal disturbance in the suspension, and only the position of the sample in the vertical direction needs to be controlled to realize stability, and the parameter debugging time of the control system can be greatly saved.

[0025] The heating sample in the utility model is a spherical sample with a diameter of 1-3mm, and the small surface area can effectively reduce the external radiation of the sample. The sample is suspended by the high-speed airflow, heat is prevented from being transferred away from the container in contact with the sample, the gas is a thermal non-conductor, the heat transfer efficiency from the suspended gas is low, and therefore the sample can be heated to 3000K. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is the whole structure schematic view of the utility model;

[0027] Figure 2 It is the structure schematic view of the sample cavity and the mounting platform after being split;

[0028] Figure 3 It is the structure schematic view of the furnace cavity after being split;

[0029] Figure 4 It is the internal structure schematic view of the furnace cavity;

[0030] Figure 5 It is the cross section schematic view of the suspension structure;

[0031] Figure 6 It is the local enlarged view of the nozzle mouth;

[0032] Figure 7 It is the temperature and position control schematic view of the laser furnace;

[0033] Figure 8 It is the thermal simulation temperature distribution cloud picture of the 3mm sample in suspension when using 200W laser heating;

[0034] Reference signs:

[0035] 10-furnace cavity; 11-upper cover; 111-heating laser; 112-infrared temperature measuring instrument; 113-second CCD camera; 12-suspension platform; 13-nozzle; 131-nozzle mouth; 132-lower cavity body; 133-steady flow cavity; 134-capillary groove; 141-air inlet pipeline; 142-air outlet port; 143-air passage interface; 151-water inlet pipeline; 152-cooling water flow channel; 153-water cooling cavity; 154-water outlet pipeline; 155-water passage interface; 161-neutron incidence window; 162-neutron emission window; 163-neutron scattering window; 164-optical window; 165-sample transfer window;

[0036] 20-mounting platform; 21-positioning laser; 22-first CCD camera; 23-optical position sensor; 30-base; 31-reflecting device. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present utility model.

[0038] In the description of the present utility model, it should be noted that the directions or position relationships indicated by the terms "vertical direction", "upper", "lower", "horizontal" and the like are based on the directions or position relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present utility model. In addition, "first", "second", "third", "fourth" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0039] In the description of the present utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be connected through an intermediate medium, it can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present utility model can be understood according to the specific circumstances.

[0040] As shown in Figures 1 to 8 The utility model discloses an air suspension laser heating furnace for neutron scattering, which comprises a furnace cavity 10, a mounting platform 20 arranged at the upper end of the furnace cavity 10, and a base 30 arranged at the lower end of the furnace cavity 10.

[0041] In the embodiment, a positioning laser 21, a first CCD camera 22 and an optical position sensor (PSD) 23 are arranged on the mounting platform 20, and the positioning laser 21 and the optical position sensor 23 cooperate with each other to monitor the suspension height of the sample in real time. An upper cover 11 is arranged between the furnace cavity 10 and the mounting platform 20, the upper end of the upper cover 11 is provided with a heating laser 111, an infrared temperature detector 112 and a second CCD camera 113 penetrating through the upper cover 11. The second CCD camera 113 is arranged at an angle of 20° with the axis of the nozzle port 131, and is used for observing the state change of the sample surface; in the embodiment, a 200W laser is vertically arranged to irradiate and heat the sample, so that the uneven heating of the sample surface is avoided to cause disturbance.

[0042] In the embodiment, the furnace cavity 10 is provided with a suspension platform 12, a nozzle 13 arranged on the upper end surface of the suspension platform 12, and an airflow system connected with the nozzle 13. The nozzle 13 comprises a nozzle port 131, and a plurality of capillary grooves 134 are arranged on the periphery of the nozzle port 131. The airflow system is used for conveying the airflow for suspension. The nozzle 13 is used for spraying gas and suspending materials. In the embodiment, the nozzle 13 adopts a detachable fixing mode, and can be matched and replaced with nozzles 13 suitable for samples with different diameters. The nozzle port 131 is provided with three capillary grooves 134. When the sample does not take off, a small amount of gas is allowed to flow out from the capillary grooves 134 around the bottom of the sample, which can reduce the upward acceleration of the sample in the suspension moment and increase the stability of the sample in the suspension take-off.

[0043] In the embodiment, the nozzle 13 further comprises a lower cavity 132 and a flow stabilizing cavity 133. The nozzle port 131 is connected with the lower cavity 132 through a constricted neck, and the flow stabilizing cavity 133 is connected with the lower end of the lower cavity 132. The nozzle port 131 is a conical cavity with the bottom surface upward, and the lower cavity 132 is a conical cavity with the bottom surface downward. In the embodiment, the airflow is guided to flow uniformly around the sample by the conical nozzle 13. Once the sample deviates from the central position of the nozzle 13 in the suspension, the gas flow on the surface of the sample is not uniform, so that the sample automatically returns to the central position. Therefore, the sample will not be disturbed in the horizontal direction in the suspension, and only the position of the sample in the vertical direction needs to be controlled to realize the stability, so that the parameter debugging time of the control system can be greatly saved.

[0044] In the embodiment, the airflow system comprises an air inlet pipeline 141 and an air outlet port 142. The air inlet pipeline 141 is connected with the lower end of the flow stabilizing cavity 133, and the air outlet port 142 is arranged on the upper cover 11. The air inlet pipeline 141 is connected with the air duct interface 143 on the furnace cavity 10.

[0045] In the embodiment, the furnace cavity 10 is further provided with a cooling system. The cooling system comprises a water inlet pipeline 151, a cooling water flow channel 152, a water cooling cavity 153, and a water outlet pipeline 154. The furnace cavity 10 is provided with a water channel interface 155 connected with the water inlet pipeline 151 and the water outlet pipeline 154, respectively. The water inlet pipeline 151 and the water outlet pipeline 154 are connected with the water cooling cavity 153 through the cooling water flow channel 152. The water cooling cavity 153 is annularly arranged on the outer periphery of the nozzle 13 and exchanges heat with the nozzle 13. The nozzle 13 and the suspension platform 12 are provided with a cooling cavity, which has a simple structure and can directly cool the nozzle 13, so as to avoid deformation of the nozzle 13 caused by overheating.

[0046] In the embodiment, the furnace cavity 10 is provided with a neutron incident window 161, a neutron emission window 162, a neutron scattering window 163, an optical window 164 and a sample transfer window 165. The base 30 is provided with a reflecting device 31 matched with the optical window 164. The heating sample of the utility model is a spherical sample with a diameter of 1-3 mm. Specifically, the heating sample of the embodiment is a spherical sample with a diameter of 3 mm, and the surface area is small, so that the external radiation of the sample can be effectively reduced. Since the high-speed gas flow makes the sample suspended, heat is prevented from being transferred away from the container in contact with the sample, and the gas is a thermal non-conductor, so that the heat transfer efficiency from the suspended gas is low, and therefore the sample can be heated to 3000K.

[0047] The working process of the utility model is as follows:

[0048] Firstly, the spherical sample is placed at the gas outlet of the nozzle 13, the high-speed argon gas flows into the steady flow cavity 133 through the gas inlet pipeline 141, the gas channel is stabilized in the steady flow cavity 133, the argon gas is converged in the lower cavity 132, the gas pressure is reduced and the flow rate is increased, the gas channel is diverged in the lower cavity 132, the pressure is slightly increased and the flow rate is further increased, the lower surface of the sample is impacted by the high-speed gas flow, so that the sample moves upward, since the outlet of the nozzle 13 is conical, when the sample is lifted, the high-speed gas flow flows away from the four sides of the sample, so that the sample is suspended.

[0049] After the sample is suspended, the sample is heated by using a 200W single-beam laser, and the laser spot diameter is 1.5mm: during the heating process of the sample, the infrared temperature detector 112 is used to monitor the surface temperature of the sample. The sample can be heated after being suspended, so that the heat loss caused by the direct contact between the container and the sample during the heating process can be avoided.

[0050] When the sample is heated by the laser, since the increase of the surface temperature of the sample will cause the change of the flow rate of the argon gas, the optical position sensor 23 (PSD) and the positioning laser 21 are needed to monitor the suspension height of the sample in real time, then the flow rate of the argon gas is accurately adjusted to make the sample suspended stably, the PSD and the positioning laser 21 are installed on the mounting platform 20, the laser emitted by the positioning laser 21 is reflected by the reflecting mirror, then enters the cavity through the optical window 164 on the furnace cavity 10, and is emitted to the light-receiving element of the PSD through the other optical window 164 and the reflecting mirror, so that the position of the suspended sample is detected.

[0051] In addition, when the neutron scattering experiment is performed, the heating temperature of the sample is generally high, in order to avoid the oxidation of the sample, it is needed to ensure that the sample is in the argon atmosphere with high purity, and the experimental process is as follows:

[0052] (1) Before the experiment starts, the exhaust port 142 is connected with the vacuum pump, the air in the sample cavity is pumped away, then the argon is introduced into the cavity through the gas channel interface 143 on the furnace cavity 10 which communicates between the cavity and the outside, and the above process is repeated for several times.

[0053] (2) The furnace cavity 10 has multiple windows, including a neutron incident window 161 and an exit window with high neutron transmission, a neutron scattering window 163 and an optical observation window, and after the furnace is installed and connected, the whole is installed in a spallation neutron source spectrometer.

[0054] (3) The spectrometer end is installed, the outer wall of the furnace cavity 10 and the inner wall of the spallation neutron source spectrometer form a scattering cavity, the gas flow is adjusted, the centers of all the windows are aligned with the suspended sample, and the sample suspension is completed.

[0055] (4) The laser is turned on to heat the sample.

[0056] (5) After reaching the target temperature, the neutron experiment is started, the neutron beam is recorded, and the experimental data is recorded.

[0057] In order to observe the changes of the sample surface in real time during the high-temperature heating experiment and improve the efficiency of debugging the laser light path, the utility model provides two sets of sample observation cameras, one set of camera is installed on the upper cover 11, the observation angle is 20 ° with the nozzle 13 axis angle, another set is installed on the mounting platform 20, and the same light path design as the positioning laser is adopted.

[0058] The utility model avoids the direct contact between the sample and the container, reduces the heat scattering of the sample at high temperature, and the utility model can heat the sample of any material, and can realize the heating of the sample from solid to molten state. According to the thermal simulation temperature distribution cloud picture, the utility model can heat the sample with a diameter of 3mm to 3000K. The utility model can observe the change of the sample surface state at any time during the heating process, and can observe the suspension height of the sample through the CCD camera, and improves the experimental operation efficiency.

[0059] The utility model also designs a nozzle 13 with a water cooling cavity 153, which can avoid the deformation of the gas flow channel caused by the large temperature rise of the nozzle port 131 during the heating process, and affect the stability of the sample suspension.

[0060] The key point of the utility model discloses is based on the principle of aerodynamic suspension cooperates with laser heating, realizes containerless heating and avoids sample and other components contact heat conduction, can heat sample to 3000K neutron scattering laser heating furnace. The utility model discloses adopts a 200W laser vertical sample irradiation heating, avoids the disturbance caused by uneven heating of sample surface. The nozzle 13 in the utility model discloses adopts detachable fixed mode, can match and replace the nozzle 13 suitable for different diameter samples. There is cooling cavity between nozzle 13 and suspension platform 12, and the structure is simple, and nozzle 13 can be cooled directly, avoids the deformation caused by overheating of nozzle 13. The nozzle mouth 131 is opened three capillary grooves 134, when sample does not take off, allows small amount of gas to flow out from the capillary groove 134 around the bottom of sample, can reduce the upward acceleration of sample suspension instant, can increase the stability of sample suspension take-off.

[0061] The above only expresses the preferred technical scheme of the utility model, and the description is more specific and detailed, but it can not be understood as the limitation of the utility model patent scope. It should be pointed out that for ordinary skilled person in the art, without departing from the concept of the utility model, a number of modifications and improvements can be made, and the utility model also intends to include these changes and modifications.

Claims

1. An aerosolized laser-heated furnace for neutron scattering, characterized by: The furnace cavity, the installation platform arranged at the upper end of the furnace cavity, and the base arranged at the lower end of the furnace cavity, the installation platform is provided with a positioning laser, a first CCD camera and an optical position sensor, the positioning laser and the optical position sensor cooperate with each other to monitor the suspension height of the sample in real time. The upper end of the upper cover is provided with a heating laser, an infrared temperature detector and a second CCD camera penetrating the upper cover, and the second CCD camera is used to observe the state change of the sample surface. The furnace cavity is provided with a suspension platform, a nozzle arranged on the upper end face of the suspension platform, and an airflow system connected with the nozzle, the nozzle comprises a nozzle port, and a plurality of capillary grooves are arranged on the periphery of the nozzle port; the airflow system is used for conveying the airflow for suspension; the nozzle is used for spraying gas and suspending materials.

2. Aerosolized laser heating oven for neutron scattering according to claim 1, characterized in that: The second CCD camera and the axis of the nozzle port form an angle of 20°.

3. The gas suspension laser heating furnace for neutron scattering of claim 1, wherein: The nozzle further comprises a lower cavity and a steady flow cavity, the nozzle port and the lower cavity are connected through a neck part, the steady flow cavity is connected to the lower end of the lower cavity, the nozzle port is a conical cavity with the bottom surface upward, and the lower cavity is a conical cavity with the bottom surface downward.

4. Aerosolized laser heating oven for neutron scattering according to claim 3, characterized in that: The airflow system comprises an air inlet pipeline and an air outlet port, the air inlet pipeline is connected to the lower end of the steady flow cavity, and the air outlet port is arranged on the upper cover.

5. Aerosolized laser heating oven for neutron scattering according to claim 4, characterized in that: An air channel interface is arranged on the furnace cavity and connected with the air inlet pipeline.

6. The gas suspension laser heating furnace for neutron scattering of claim 1, wherein: A cooling system is further arranged in the furnace cavity, the cooling system comprises a water inlet pipeline, a cooling water flow channel, a water cooling cavity and a water outlet pipeline, the water inlet pipeline and the water outlet pipeline are communicated with the water cooling cavity through the cooling water flow channel, and the water cooling cavity is arranged on the outer periphery of the nozzle and exchanges heat with the nozzle.

7. Aerosolized laser heating oven for neutron scattering according to claim 6, characterized in that: Water channel interfaces are arranged on the furnace cavity and connected with the water inlet pipeline and the water outlet pipeline respectively.

8. The gas suspension laser heating furnace for neutron scattering of claim 1, wherein: A neutron incident window, a neutron emission window, a neutron scattering window, an optical window and a sample transfer window are arranged on the furnace cavity.

9. Aerosol laser heating oven for neutron scattering according to claim 8, characterized in that: A reflecting device matched with the optical window is arranged on the base.

10. Aerosol laser heating oven for neutron scattering according to any one of claims 1 to 9, characterized in that: The heating laser adopts a 200W single-beam laser, and the laser spot diameter is 1.5mm.

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