Heating device

Abstract

The application relates to the technical field of cold atoms, in particular to a heating device for generating an atomic vapor flow. The device comprises a first furnace body and a second furnace body, the inner cavity of the first furnace body is communicated with the inner cavity of the second furnace body through a communication port, the second furnace body is provided with a gas outlet communicated with the inner cavity of the second furnace body, the outer wall of the first furnace body is provided with a heat source layer for heating the first furnace body, the second furnace body at least comprises a first temperature drop section and a second temperature drop section arranged in sequence along the direction from the communication port to the gas outlet, the thermal resistance value of the first temperature drop section and the thermal resistance value of the second temperature drop section make the temperature of the second furnace body connected with the first furnace body change according to a preset temperature drop curve, the abscissa of the temperature drop curve is the axial distance of the second furnace body, and the ordinate is the temperature value. The heating device is designed by segmenting the thermal resistance value of the second furnace body, so that the second furnace body can realize temperature drop according to the preset temperature drop curve, stable temperature control can be realized by only one heat source, and the structure and control are relatively simple.

Description

Technical Field

[0001] This application relates to the field of cold atom technology, specifically to a heating device for generating atomic vapor streams (atomic beams). Background Technology

[0002] A nuclear furnace is a heating device used to generate vacuum sputtered atomic and molecular beams. Vacuum sputtered atomic and molecular beams have wide applications in condensed matter physics, atomic and molecular physics, and chemistry. To ensure the long-term and effective operation of the nuclear furnace and prevent material deposition on the furnace walls or blockage of pipes, segmented temperature control design is crucial. However, current technologies mostly employ multi-segment active temperature control, with each segment heated by a separate heat source. This type of technology is complex and requires numerous control components. Summary of the Invention

[0003] This application provides a heating device that can achieve segmented temperature control, and its structure and control are relatively simple.

[0004] This application provides a heating device, including:

[0005] First furnace body and second furnace body.

[0006] The inner cavity of the first furnace body is connected to the inner cavity of the second furnace body through a communication port.

[0007] The second furnace body has a gas outlet communicating with its own internal cavity, characterized in that:

[0008] The outer wall of the first furnace body is provided with a heat source layer for heating the first furnace body.

[0009] The second furnace body includes at least a first temperature drop section and a second temperature drop section arranged sequentially along the direction from the communication port to the gas outlet.

[0010] The thermal resistance values ​​of the first temperature drop section and the second temperature drop section can make the temperature of the second furnace body change according to a preset cooling curve, wherein the horizontal axis of the cooling curve is the axial distance and the vertical axis is the temperature value.

[0011] The first temperature drop section includes a first sub-temperature drop section and a second sub-temperature drop section arranged sequentially along the direction from the connecting port to the second temperature drop section.

[0012] The thermal resistance of the second sub-temperature drop section is related to the melting point of the object being heated inside the first furnace.

[0013] The thermal resistance of the first sub-temperature drop section is greater than the thermal resistance of the second sub-temperature drop section;

[0014] A heating resistance wire is arranged inside the heat source layer. The positive and negative ends of the heating resistance wire are arranged side by side inside the heat source layer. The heating resistance wire connecting the positive and negative ends is folded in half and extends from one end of the heat source layer to the other end in a double-line spiral form inside the peripheral wall of the heat source layer.

[0015] The heating device is mainly used to generate atomic vapor streams.

[0016] According to the foregoing embodiments of this application, the heat source layer is used to heat the first furnace body so that the object to be heated inside the first furnace body becomes steam.

[0017] The thermal resistance of the first temperature drop section is related to the melting point of the object being heated in the first furnace.

[0018] According to any of the foregoing embodiments of this application, the thermal resistance of the first temperature drop section keeps the heated object entering the first furnace body in a non-solid state within the first furnace body.

[0019] According to any of the foregoing embodiments of this application, the inner diameter of the first furnace body is larger than the inner diameter of the second furnace body.

[0020] According to any of the foregoing embodiments of this application, a flange is connected at the gas outlet, and the flange is used to seal the second furnace body to the external cavity.

[0021] According to any of the foregoing embodiments of this application, an insulation layer is wrapped around the outer periphery of the first furnace body and the outer periphery of the second furnace body, and the heat source layer is located between the insulation layer and the outer wall of the first furnace body.

[0022] According to any of the foregoing embodiments of this application, the heating device further includes a cooling layer for cooling, which wraps around the insulation layer and the outer periphery of the flange.

[0023] According to any of the foregoing embodiments of this application, a coolant channel is provided within the cooling layer.

[0024] According to any of the foregoing embodiments of this application, the coolant passage includes an inlet, an outlet, and a coolant flow channel connecting the inlet and the outlet, wherein the inlet and the outlet are located on the side of the heating device opposite to the flange.

[0025] According to any of the foregoing embodiments of this application, the coolant flow channel extends from the inlet to the location of the flange, and then extends from the location of the flange to the outlet.

[0026] According to any of the foregoing embodiments of this application, the coolant flow channel extends in a spiral form from the inlet to the outer peripheral wall of the flange within the peripheral wall of the cooling layer, and then extends in a spiral form from the outer peripheral wall of the flange to the outlet.

[0027] According to any of the foregoing embodiments of this application, a heating resistance wire is arranged in the heat source layer.

[0028] According to any of the foregoing embodiments of this application, in the heat source layer, the positive and negative terminals of the heating resistance wire are arranged side by side, and the heating resistance wire connecting the positive and negative terminals is folded in half and extends from one end of the heat source layer to the other end in a double-wire spiral form in the peripheral wall of the heat source layer.

[0029] According to any of the foregoing embodiments of this application, the heating resistance wire is folded in half and extends in a double-helix form within the peripheral wall of the heat source layer from one end of the heat source layer opposite to the second furnace body to the end where the second furnace body is located.

[0030] According to any of the foregoing embodiments of this application, the heating resistance wires of adjacent rings are spaced apart, and the distance between the heating resistance wires of adjacent rings along the axial direction of the heat source layer is equal.

[0031] According to any of the foregoing embodiments of this application, at least one temperature sensor is provided at each of the first furnace body, the first sub-temperature drop section, the second sub-temperature drop section, and the second temperature drop section.

[0032] According to any of the foregoing embodiments of this application, the heating device further includes a temperature controller, which is used to receive temperature values ​​fed back by temperature sensors corresponding to the first furnace body, the first sub-temperature drop section, the second sub-temperature drop section, and the second temperature drop section; and / or

[0033] The thermostat is also used to control the heating temperature of the heat source layer.

[0034] The heating device of this application embodiment, by designing the thermal resistance of the second furnace body in segments, enables the second furnace body to cool down according to a preset cooling curve. Compared with the traditional method of heating each section of the furnace body with a separate heat source, the heating device of this application embodiment only needs one heat source to achieve stable temperature control, and the structure and control are relatively simple. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a heating device according to an embodiment of this application;

[0036] Figure 2 This is a schematic diagram of the structure of a heating device according to an embodiment of this application;

[0037] Figure 3a and Figure 3b This is a schematic diagram of the structure of the heat source layer according to an embodiment of this application;

[0038] Figure 4 This is a schematic diagram of the structure of the first furnace body and the second furnace body according to an embodiment of this application;

[0039] Figure 5 This is a schematic diagram of the cooling layer structure according to an embodiment of this application;

[0040] Figure 6 This is a schematic diagram of a preset cooling curve in an embodiment of this application;

[0041] Figure 7 This is a temperature simulation diagram of the atomic furnace in an embodiment of this application. Detailed Implementation

[0042] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0043] This application provides a heating device 100, mainly used to generate an atomic vapor stream (atomic beam) and transport gaseous atoms to a two-dimensional magneto-optical trap cavity (not shown in the figure) connected to the heating device 100 for the study of cold atom-related issues. The heating device 100 is generally cylindrical, but it can also be designed as other cylindrical shapes, such as elliptical cylinders, as needed.

[0044] Please see Figure 1The heating device 100 provided in this application embodiment includes a first furnace body 110 and a second furnace body 120. Depending on the actual usage scenario, the first furnace body 110 and the second furnace body 120 can be in a vertical or horizontal positional relationship. This application embodiment is described with the first furnace body 110 located at the lower part and the second furnace body 120 located at the upper part as an example. The outer wall of the first furnace body 110 is provided with a heat source layer 130 for heating the first furnace body 110. The heat source layer 130 generates heat, causing the object to be heated placed in the inner cavity of the first furnace body 110 to become a vapor flow. The object to be heated can be various metals, such as lithium, sodium, potassium, rubidium, cesium, etc. In this embodiment, lithium is used as an example for description. The inner cavity of the first furnace body 110 is connected to the inner cavity of the second furnace body 120 through a communication port 140, that is, the first furnace body 110 and the second furnace body 120 are fluidly connected. The second furnace body 120 has a gas outlet 121 that communicates with its own inner cavity. Since there is no heat source for heating the second furnace body 120, the heated first furnace body 110... A temperature difference is formed between furnace body 110 and the second furnace body 120. The temperature of the second furnace body 120 gradually decreases from the end connected to the first furnace body 110 to the other end of the second furnace body 120. The vapor pressure inside the second furnace body 120 also gradually decreases. Therefore, the lithium being heated in the first furnace body 110, after being heated by the heat source layer 130 and becoming lithium vapor, will enter the second furnace body 120 under the action of the vapor pressure difference and move towards the gas outlet 121 of the second furnace body 120. In order to control the flow rate of lithium vapor entering the second furnace body 120 and to prevent lithium atoms from adhering to the inner wall of the second furnace body 120, the second furnace body 120 is specially designed as follows:

[0045] The second furnace body 120 includes at least a first temperature drop section 122 and a second temperature drop section 123. The first temperature drop section 122 and the second temperature drop section 123 are arranged sequentially along the direction from the connecting port 140 to the gas outlet 121. The thermal resistance values ​​of the first temperature drop section 122 and the second temperature drop section 123 cause the temperature of the second furnace body 120, which is connected to the first furnace body 110, to change according to a preset cooling curve. Figure 6 As shown, the horizontal axis of the preset cooling curve represents the axial distance, and the vertical axis represents the temperature value. The axial distance refers to the distance between each cross-section of the first furnace body 110 and the second furnace body 120 and the bottom surface of the first furnace body 110. The starting temperature of the preset cooling curve is the temperature at which the heated object is converted into vapor and the atomic beam is directed at a preset flux (e.g., if the heated object is lithium, the flux is 10). 12 The target temperature for lithium atoms entering the two-dimensional magneto-optical trap cavity (based on the principle of thermal evaporation sputtering and the final flux of lithium atoms entering the magneto-optical trap cavity) can be calculated, and then converted into temperature; for example, if the heated object is lithium, and the flux is 10 12If the target temperature is 350℃ (if the heat rate is 1 / s), the furnace wall temperature of the second furnace body 120 can be made to change according to a preset cooling curve by reasonably setting the thermal resistance values ​​of the first temperature drop section 122 and the second temperature drop section 123. It should be noted that the thermal resistance values ​​of the first temperature drop section 122 and the second temperature drop section 123 can be equal or unequal.

[0046] Taking lithium metal as an example, the first furnace body 110 is heated to a temperature of 350°C. The lithium within the first furnace body 110, after heating, becomes lithium vapor and is ejected into the second furnace body 120. In the first temperature drop section 122 near the first furnace body 110, due to the scattering of lithium atoms, some lithium atoms will sputter onto the inner wall of the first temperature drop section 122. To prevent these lithium atoms from adhering to the inner wall of the first temperature drop section 122, the thermal resistance of the first temperature drop section 122 is appropriately set to ensure that the first temperature drop section... If the temperature at 122 is maintained above the melting point of lithium atoms, then the lithium atoms sputtered onto the inner wall of the first temperature drop section 122 will not solidify. Instead, they will flow back along the inner wall of the first temperature drop section 122 into the first furnace body 110, where they will be heated again. This process repeats. The remaining lithium vapor that does not sputter onto the inner wall of the first temperature drop section 122 continues to move towards the gas outlet 121, reaching the second temperature drop section 123. In the second temperature drop section 123, the number of lithium atoms sputtered onto its inner wall decreases, and they are less likely to adhere to the inner wall. By appropriately setting the thermal resistance of the second temperature drop section 123, the temperature at the gas outlet 121 can be made to reach the temperature required for the experiment.

[0047] As the above analysis shows, the selection of the preset cooling curve is highly variable, varying depending on the object being heated and the desired flow rate at gas outlet 121. Therefore, the thermal resistance values ​​of the first temperature drop section 122 and the second temperature drop section 123 of the second furnace body 120 also have many possibilities. The thermal resistance value is directly proportional to L / D and inversely proportional to dD, where L is the length of the corresponding temperature drop section of the second furnace body 120, D is the inner diameter of the corresponding temperature drop section of the second furnace body 120, and dD is the wall thickness of the corresponding temperature drop section of the second furnace body 120. Therefore, even if the preset cooling curve remains unchanged, the structure of the second furnace body 120 can have multiple possibilities.

[0048] If the object to be heated is liquid at room temperature, the main purpose of designing the thermal resistance of each section of the second furnace body 120 is to ensure that the atomic beam enters the two-dimensional magneto-optical trap cavity according to the preset flux. If the object to be heated is solid at room temperature, the main purpose of designing the thermal resistance of each section of the second furnace body 120 is to ensure that the atomic beam does not adhere to the inner wall of the second furnace body 120 due to sputtering, and that the atomic beam enters the two-dimensional magneto-optical trap cavity according to the preset flux.

[0049] Compared to traditional techniques that use multiple heat sources to heat different parts of the furnace body to achieve multi-stage temperature control, the heating device 100 of this application embodiment achieves multi-stage temperature control through a special thermal resistance design of the second furnace body 120. This design is ingenious, simple in structure, and reduces costs. Figure 7 The simulation results show that when the first furnace body 110 is heated to 350°C, each section of the second furnace body 120 cools down according to the preset cooling curve. It can be seen that the heating device in this embodiment has a good temperature control effect.

[0050] In some embodiments, when the object to be heated is solid at room temperature, the heat source layer 130 is used to heat the first furnace body 110 so that the object to be heated inside the first furnace body 110 changes from solid to vapor. The thermal resistance of the first temperature drop section 122 is related to the melting point of the object to be heated inside the first furnace body 110, so that the vapor flow entering the first temperature drop section 122 will not partially adhere to the inner wall of the first temperature drop section 122 due to sputtering. Specifically, the thermal resistance of the first temperature drop section 122 keeps the object to be heated inside the first furnace body 110 non-solid. After the cooling effect of the first temperature drop section 122, the temperature at the end of the first temperature drop section 122 (the end connected to the second temperature drop section 123) is still greater than the melting point of the object to be heated. This ensures that the temperature of the entire first temperature drop section 122 is greater than the melting point of the object to be heated, so that the vapor flow sputtered onto the inner wall of the first temperature drop section 122 will not condense into a solid and adhere to the inner wall, thereby blocking the furnace body. For example, if the object to be heated is lithium, then the thermal resistance of the first temperature drop section 122 needs to be guaranteed, and the temperature at the end of the first temperature drop section 122 needs to be greater than 180°C.

[0051] Please see Figure 2 In some embodiments, to further reduce the probability of atomic flow adhering to the first temperature drop section 122, the first temperature drop section 122 further includes a first sub-temperature drop section 1221 and a second sub-temperature drop section 1222 arranged sequentially along the direction from the connection port 140 to the second temperature drop section 123. The thermal resistance value of the second sub-temperature drop section 1222 is related to the melting point of the object being heated in the first furnace body 110, and the thermal resistance value of the first sub-temperature drop section 1221 is greater than the thermal resistance value of the second sub-temperature drop section 1222. For example, if the object being heated is lithium, then the thermal resistance values ​​of the first sub-temperature drop section 1221 and the second sub-temperature drop section 1222 need to ensure that the temperature at the end of the second sub-temperature drop section 1222 is greater than 180°C, and that the thermal resistance value of the first sub-temperature drop section 1221 is greater than the thermal resistance value of the second sub-temperature drop section 1222.

[0052] Please see Figure 1In some embodiments, to guide and collimate the steam flow, the inner diameter of the first furnace body 110 is larger than that of the second furnace body 120. The inner wall of the second furnace body 120 is cylindrical with a constant diameter. After the steam flow exits from the inner cavity of the first furnace body 110, it enters the inner cavity of the second furnace body 120. Since the inner diameter of the second furnace body 120 is smaller than that of the first furnace body 110, it can guide and collimate the steam flow. As the steam flow gets closer to the direction of the gas outlet 121, the sputtering effect decreases, and fewer atoms are sputtered onto the inner wall of the second furnace body 120. Furthermore, after collimation, it becomes increasingly difficult for atoms to adhere to the inner wall of the second furnace body.

[0053] Please see Figure 1 In some embodiments, in order to generate an atomic beam and analyze atoms in a vacuum environment, a flange 150 is connected to the gas outlet 121. The flange 150 is used to seal the second furnace body 120 to an external cavity (e.g., a two-dimensional magneto-optical trap cavity).

[0054] Flange 150 is connected to the second furnace body 120. Heat from the second furnace body 120 will be transferred to flange 150. In order to prevent heat from being conducted to the external cavity and causing damage to the external cavity, the temperature of flange 150 needs to be reduced to room temperature without affecting the temperature of the first furnace body 110 and the second furnace body 120.

[0055] Please see Figure 1 In some embodiments, to prevent the heating device 100 from radiating heat to the outside, an insulation layer 160 is wrapped around the outer periphery of the first furnace body 110 and the outer periphery of the second furnace body 120. The heat source layer 130 is located between the insulation layer 160 and the outer wall of the first furnace body 110. The insulation layer 160 can be made of a material with a low thermal conductivity, such as aluminosilicate ceramic 132 fiber blanket, nano-aerogel, etc. The insulation layer 160 uniformly wraps around the heat source layer 130 and the rest of the furnace body, including the outer periphery and bottom wall of the first furnace body 110 and the outer wall of the second furnace body 120. Of course, for connection with the flange 150, the insulation layer 160 wraps around the part of the furnace body connected to the flange 150.

[0056] Please see Figure 1 , Figure 5 In some embodiments, in order to cool down the flange 150 and keep it at room temperature, the heating device 100 further includes a cooling layer 170 for cooling. The cooling layer 170 is wrapped around the insulation layer 160 and the outer periphery of the flange 150, including the bottom of the first furnace body 110 and corresponding parts such as the first furnace body 110, the second furnace body 120, and the peripheral sidewalls of the flange 150.

[0057] Specifically, a coolant channel 171 is provided within the cooling layer 170. The coolant channel 171 includes an inlet 1711, an outlet 1712, and a coolant flow channel 1713 connecting the inlet 1711 and the outlet 1712. The coolant reaches the flange 150 through the coolant channel 171, carrying away heat from the flange 150 and keeping it at room temperature, preventing excessive heat from damaging the two-dimensional magneto-optical trap connected to it. Simultaneously, it also prevents the heat generated by the heat source layer 130 from affecting the external environment.

[0058] In some embodiments, the inlet 1711 and outlet 1712 are located on the side of the heating device 100 opposite to the flange 150, for example, below the bottom of the first furnace body 110. Since the bottom of the first furnace body 110 is not connected to other components, the inlet 1711 and outlet 1712 are conveniently located, saving space and not affecting other components.

[0059] Please see Figure 5 In some embodiments, the coolant flow channel 1713 extends from the inlet 1711 toward the flange 150, and then extends from the flange 150 toward the outlet 1712. For example, the coolant flow channel 1713 extends in a spiral form from the inlet 1711 to the outer peripheral wall of the flange 150 within the peripheral wall of the cooling layer 170 (this section can be referred to as the inlet flow channel 17131), and then extends in a spiral form from the outer peripheral wall of the flange 150 to the outlet 1712 (this section can be referred to as the outlet flow channel 17132). This double-helix coolant channel 1713 has the inlet and outlet directions opposite, resulting in more uniform heat dissipation and higher heat exchange efficiency. The coolant channel 1713 is in direct contact with the vacuum flange 150. By setting the coolant temperature, the flange 150 can be forcibly cooled, creating a temperature difference with the second furnace body 120. Combined with the special thermal resistance design of the second furnace body 120, the heat flow is controlled, thereby controlling the flow rate of the steam flow. At the same time, it ensures that there is no thermal impact on the external environment.

[0060] Please see Figure 3a and Figure 3b In some embodiments, a heating resistance wire 131 is arranged within the heat source layer 130. The heating resistance wire 131 is externally wrapped with ceramic 132 for heat insulation, and the inner wall heating portion is composed of a metal layer 133 with good thermal conductivity. The heating resistance wire 131 can be wound back and forth along the outer peripheral wall of the first furnace body 110, from the bottom to the top of the first furnace body 110, until it covers the entire outer peripheral wall of the first furnace body 110. Alternatively, it can be as follows... Figure 3bAs shown, within the heat source layer 130, the positive and negative terminals of the heating resistance wire 131 are arranged side-by-side. The heating resistance wire 131, connecting the positive and negative terminals, is folded in half and extends in a double-spiral form within the peripheral wall of the heat source layer 130 from one end of the heat source layer 130 to the other. Preferably, the folded heating resistance wire 131 extends in a double-spiral form within the peripheral wall of the heat source layer 130 from the end of the heat source layer 130 opposite to the second furnace body 120 towards the end where the second furnace body 120 is located. On one hand, the positive and negative terminals of the heating resistance wire 131 can be evenly positioned at the bottom of the first furnace body 110, and a wiring hole 172 is provided in the cooling layer 170 below the bottom of the first furnace body 110; on the other hand, the heating resistance wire 131 adopts... Figure 3b The double-strand non-inductive winding method shown is uniformly fixed on the metal layer 133, so that the current direction of two adjacent turns of heating resistance wire 131 is opposite, thereby minimizing the influence of the magnetic field.

[0061] In some embodiments, adjacent turns of heating resistance wire 131 are spaced apart, and the distance between adjacent turns of heating resistance wire 131 along the axial direction of the heat source layer 130 is equal. This can counteract the magnetic field, thereby eliminating its influence.

[0062] Please see Figure 4 In some embodiments, at least one temperature sensor 180 is provided at each of the first furnace body 110, the first sub-temperature drop section 1221, the second sub-temperature drop section 1222, and the second temperature drop section 123. The temperature sensors 180 are preferably located at the end of each furnace body closest to the flange 150. The heating device 100 also includes a thermostat 190, which is used to receive the temperature values ​​fed back by the temperature sensors 180 corresponding to the first furnace body 110, the first sub-temperature drop section 1221, the second sub-temperature drop section 1222, and the second temperature drop section 123. The thermostat 190 can also be used to control the heating temperature of the heat source layer 130, thereby ensuring that the temperature inside the first furnace body 110 reaches the preset temperature and that the temperature of the second furnace body 120 changes according to the preset cooling curve, thereby achieving stable cooling.

[0063] The working principle of the heating device 100 in this embodiment is as follows: First, the temperature of the heat source layer 130 (a temperature exceeding the boiling point of the object being heated) is set according to the requirements, and the actual required steam flow rate is used to determine the preset cooling curve, thereby determining the temperature drop gradient of the second furnace body 120. The coolant temperature is set according to the temperature to be reached at the flange 150 and the temperature drop gradient of the second furnace body 120. After the setting is completed and the power is turned on, the constant temperature controller 190 adjusts the current of the heating resistance wire 131 in real time according to the temperature value fed back by the temperature sensor 180, so as to realize gradient heating and control of stable gas flow rate.

Claims

1. A heating device, comprising: a first furnace body and a second furnace body, an inner cavity of the first furnace body and an inner cavity of the second furnace body are communicated through a communication port, the second furnace body has a gas outlet communicated with the inner cavity of the second furnace body, characterized in that: an outer wall of the first furnace body is provided with a heat source layer for heating the first furnace body, the second furnace body comprises at least a first temperature drop section and a second temperature drop section arranged in sequence along a direction from the communication port to the gas outlet, a thermal resistance value of the first temperature drop section and a thermal resistance value of the second temperature drop section can make the temperature of the second furnace body change according to a preset temperature drop curve, the abscissa of the temperature drop curve is an axial distance, and the ordinate of the temperature drop curve is a temperature value, the first temperature drop section comprises a first sub-temperature drop section and a second sub-temperature drop section arranged in sequence along a direction from the communication port to the second temperature drop section, the thermal resistance value of the second sub-temperature drop section is related to a melting point of a heating object in the first furnace body, the thermal resistance value of the first sub-temperature drop section is greater than the thermal resistance value of the second sub-temperature drop section, the heat source layer is arranged with heating resistance wires, in the heat source layer, an anode end and a cathode end of the heating resistance wires are arranged side by side, and the heating resistance wires are folded after being connected to the anode end and the cathode end, and then extend in a double-line spiral form in a circumferential side wall of the heat source layer from one end of the heat source layer to the other end of the heat source layer, and the heating device is used for generating an atomic vapor flow, the heat source layer is used for heating the first furnace body to make the heating object in the first furnace body become vapor, and the thermal resistance value of the first temperature drop section is related to the melting point of the heating object in the first furnace body. 3.The heating device according to claim 2, characterized in that: the thermal resistance value of the first temperature drop section makes the heating object entering the first furnace body keep non-solid state in the first furnace body, the inner cavity diameter of the first furnace body is greater than the inner cavity diameter of the second furnace body, a flange plate is connected at the gas outlet, the flange plate is used for sealingly connecting the second furnace body with an external cavity, a heat preservation layer is wrapped around the outer periphery of the first furnace body and the outer periphery of the second furnace body, the heat source layer is located between the heat preservation layer and the outer wall of the first furnace body, a temperature drop layer for temperature drop is further included, the temperature drop layer is wrapped around the outer periphery of the heat preservation layer and the flange plate, a cooling liquid channel is arranged in the temperature drop layer, the cooling liquid channel comprises a liquid inlet, a liquid outlet and a cooling liquid flow channel connecting the liquid inlet and the liquid outlet, the liquid inlet and the liquid outlet are located on a side of the heating device opposite to the flange plate, the cooling liquid flow channel extends from the liquid inlet to a position where the flange plate is located, and then extends from the position where the flange plate is located to the liquid outlet, the cooling liquid flow channel extends in a spiral form from the liquid inlet to the outer peripheral wall of the flange plate in the circumferential side wall of the temperature drop layer, and then extends in a spiral form from the outer peripheral wall of the flange plate to the liquid outlet, the heating resistance wires are folded after being connected to the anode end and the cathode end, and then extend in a double-line spiral form in the circumferential side wall of the heat source layer from an end of the heat source layer opposite to the second furnace body to the end of the heat source layer where the second furnace body is located, the heating resistance wires of adjacent turns are arranged with equal distance along the axial direction of the heat source layer. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The heating device of claim 1, wherein: ​ ​ ​ ​ 4. The heating device of claim 1, wherein: ​ 5. The heating device of claim 1, wherein: ​ 6. The heating device of claim 5, wherein: ​ 7. The heating device of claim 6, wherein: ​ 8. The heating device of claim 7, wherein: ​ 9. The heating device of claim 8, wherein: ​ 10. The heating device of claim 9, wherein: ​ 11. The heating device of claim 10, wherein: ​ 12. The heating device of claim 11, wherein: ​ 13. The heating device of claim 12, wherein: ​ 14. The heating device of claim 13, wherein: At least one temperature sensor is arranged at each of the first furnace body, the first sub-temperature drop section, the second sub-temperature drop section and the second temperature drop section.

15. The heating device of claim 14, wherein: The constant temperature controller is further configured to receive temperature values fed back by the temperature sensors corresponding to the first furnace body, the first sub-temperature drop section, the second sub-temperature drop section and the second temperature drop section. The constant temperature controller is further configured to control the heating temperature of the heat source layer.

Images