Roller kiln
By installing vortex tubes and gas compression devices in the roller kiln, the problem of low cooling efficiency is solved by using low-temperature gas to cool the cooling zone, thereby reducing the discharge temperature and improving product quality.
Patent Information
- Application Number
- CN202520131226.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2026-01-16
- Estimated Expiration
- 2035-01-20
AI Technical Summary
The low cooling efficiency of the roller kiln's cooling zone leads to high discharge temperatures, making the material susceptible to oxidation and thus reducing product quality.
A vortex tube is installed in the roller kiln. Compressed gas provided by the gas compression device passes through the vortex tube and forms low-temperature gas that enters the cooling zone, thereby improving the cooling efficiency of the cooling zone, reducing the discharge temperature, and preventing material oxidation.
The vortex tube further cools the cooling zone with low-temperature gas, improving cooling efficiency, reducing discharge temperature, preventing material oxidation, and improving product quality.
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Figure CN223807580U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to lithium electricity material sintering technical field especially relates to a roller kiln. BACKGROUND
[0002] The electrode of lithium battery is sintered from raw materials, and needs to use the roller kiln. A plurality of roller bars in the roller kiln continuously rotate under the driving of power source, and the plurality of roller bars form the roller way of the moving saggar, and the sagger of the plurality of raw material columns is moved on the roller way, and the sagger completes the preheating, calcination and cooling process of the product during the progress from the kiln head to the kiln tail.
[0003] In the related art, the cooling structure is arranged in the cooling zone of the roller kiln, and the circulating water is arranged in the cooling structure. The roller kiln adopts the circulating water heat exchange mode to cool the cooling zone.
[0004] However, the cooling efficiency of the cooling zone of the roller kiln is low, which leads to high discharge temperature, so that the material is easy to be oxidized, thereby the quality of the product is reduced. SUMMARY
[0005] The utility model discloses a roller kiln to solve the cooling efficiency of the cooling zone of the roller kiln is low, which leads to high discharge temperature, so that the material is easy to be oxidized, thereby the quality of the product is reduced.
[0006] The utility model discloses a roller kiln, comprising:
[0007] The kiln body has a cooling zone, and the cooling zone is provided with a cooling structure;
[0008] The gas compression device is arranged outside the kiln body, and the gas compression device is used for providing compressed gas;
[0009] The vortex tube is arranged outside the kiln body, and the vortex tube has an inlet, a first outlet and a second outlet, the inlet is connected with the gas compression device, the first outlet is connected with the cooling zone, and the first outlet is configured to flow out low-temperature gas.
[0010] In a possible implementation, the kiln body further has a heating zone, and the heating zone is connected with the second outlet;
[0011] The second outlet is configured to flow out high-temperature gas.
[0012] In a possible implementation, a first connecting pipe is arranged between the first outlet of the vortex tube and the cooling zone, and a second connecting pipe is arranged between the second outlet of the vortex tube and the heating zone.
[0013] In a possible implementation, the number of the vortex tubes is multiple, and each of the vortex tubes corresponds to one of the first connecting pipes.
[0014] In a possible implementation, the heating area comprises multiple heating sections, and the multiple heating sections are sequentially arranged along the conveying direction.
[0015] In a possible implementation, each of the vortex tubes corresponds to one of the second connecting pipes, and the multiple second connecting pipes are connected with at least one of the multiple heating sections.
[0016] In a possible implementation, the multiple second connecting pipes are connected with the multiple heating sections, and each of the second connecting pipes corresponds to one of the heating sections.
[0017] In a possible implementation, the gas compression device is a nitrogen compression device.
[0018] In a possible implementation, a third connecting pipe is arranged between the inlet of the vortex tube and the gas outlet pipeline of the nitrogen compression device, and a flow meter is arranged on the third connecting pipe.
[0019] In a possible implementation, the cooling structure comprises multiple heat exchange pipes connected with each other.
[0020] The roller kiln provided in the embodiment of the present application can produce low-temperature gas from the first outlet of the vortex tube after the compressed gas provided by the gas compression device enters the inlet of the vortex tube, and the low-temperature gas enters the cooling area of the kiln body, so that the cooling area can be further cooled, thereby improving the cooling efficiency of the cooling area, reducing the discharging temperature, preventing the material from being oxidized, and improving the quality of the product. BRIEF DESCRIPTION OF DRAWINGS
[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.
[0022] Figure 1 FIG. 1 is a structural schematic diagram of a roller kiln according to the embodiment of the present application;
[0023] Figure 2 FIG. 2 is a structural schematic diagram of a vortex tube in the roller kiln according to the embodiment of the present application; Figure 1
[0024] Figure 3 The structure schematic diagram of the roller kiln is provided for the second embodiment of the utility model.
[0025] Mark explanation:
[0026] 10-kiln body; 11-heating zone; 111-warming-up section; 112-first constant-temperature section; 113-second constant-temperature section; 12-cooling zone; 13-cooling structure; 20-gas compression device; 21-gas outlet pipeline; 30-vortex tube; 31-nozzle; 311-inlet; 32-vortex chamber; 33-separation orifice plate; 34-cold-end tube; 341-first outlet; 35-hot-end tube; 351-second outlet; 36-regulating valve; 41-first connecting pipe; 42-second connecting pipe; 43-third connecting pipe; 50-flow meter. DETAILED DESCRIPTION
[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.
[0028] It should be noted that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the utility model, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.
[0029] In the utility model, unless otherwise specifically defined and limited, the terms "installation", "connection", "fixation" and other terms should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0030] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.
[0031] In the above description, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or features of different embodiments or examples described in the specification without contradiction.
[0032] As described in the background, the cooling efficiency of the cooling zone of the roller kiln is low, resulting in high discharge temperature, so that the material is easy to be oxidized, thereby reducing the quality of the product.
[0033] To solve the above problems, the present application provides a roller kiln, which is provided with a vortex tube. The low-temperature gas after the compressed gas passes through the vortex tube enters the cooling zone of the kiln body, which can further cool the cooling zone, thereby improving the cooling efficiency of the cooling zone, reducing the discharge temperature, and preventing the material from being oxidized, thereby improving the quality of the product.
[0034] The roller kiln provided by the embodiments of the present application will be described in detail below in combination with specific embodiments.
[0035] Referring to Figure 1 The present application provides a roller kiln, which can be used for sintering lithium battery materials. The conveying direction of the lithium battery materials in the roller kiln is the X-axis direction.
[0036] The roller kiln can include a kiln body 10. The kiln body 10 can have a heating zone 11 and a cooling zone 12 along the conveying direction. The lithium battery material is sintered in the heating zone 11. The sintered lithium battery material is cooled in the cooling zone 12.
[0037] The cooling zone 12 can be provided with a cooling structure 13, which can cool the sintered lithium battery material. In some examples, the cooling structure 13 can include a plurality of connected heat exchange pipes, circulating water can be introduced into the heat exchange pipes, and the cooling structure 13 can adopt a circulating water heat exchange mode to cool the cooling zone 12.
[0038] The roller kiln can include a gas compression device 20. The gas compression device 20 is arranged outside the kiln body 10. The gas compression device 20 is configured with a compressor, and the gas compression device 20 is used to provide compressed gas. In some examples, the compressed gas can protect the lithium battery material in the roller kiln from oxidation.
[0039] The roller kiln can include a vortex tube 30. The vortex tube 30 can be arranged outside the kiln body 10.
[0040] Referring to Figure 2 As shown, the vortex tube 30 is composed of a nozzle 31, a vortex chamber 32, a separation orifice plate 33, a cold end tube 34, a hot end tube 35, and a regulating valve 36.
[0041] The cold end tube 34 and the hot end tube 35 are respectively arranged on both sides of the vortex chamber 32, and the cold end tube 34 and the hot end tube 35 respectively communicate with the vortex chamber 32. The cold end tube 34 has a first outlet 341, and the hot end tube 35 has a second outlet 351. The first outlet 341 can be connected with the cooling zone 12.
[0042] The nozzle 31 communicates with the vortex chamber 32. The nozzle 31 has an inlet 311.
[0043] The separation orifice plate 33 is arranged on the side of the vortex chamber 32 facing the cold end tube 34.
[0044] The regulating valve 36 is arranged at the second outlet 351 of the hot end tube 35.
[0045] The inlet 311 of the vortex tube 30 is connected with the gas compression device 20, and the first outlet 341 is connected with the cooling area 12. The compressed gas provided by the compression device can enter the nozzle 31 from the inlet 311 of the vortex tube 30 and enter the vortex chamber 32 along the tangential inlet direction, rotate along the inner wall of the vortex tube 30, and flow to the second outlet 351 at high speed due to the blocking of the separation orifice plate 33. In this process, the high-speed gas is automatically separated into two parts with different total temperatures, wherein the total temperature of the center part gas is low, and the total temperature of the outer layer part gas is high. The center low-temperature gas appears backflow phenomenon and flows to the first outlet 341 and then flows out of the first outlet 341, and the outer layer high-temperature gas flows out of the second outlet 351. Therefore, the low-temperature gas flowing out of the first outlet 341 can enter the cooling area 12 of the kiln body 10, further cool the cooling area 12, improve the cooling efficiency of the cooling area 12, reduce the discharge temperature, prevent the material from being oxidized, and thus improve the product quality.
[0046] It should be noted that the low-temperature gas flowing in the cold-end tube 34 forms a cold gas flow, and the high-temperature gas flowing in the hot-end tube 35 forms a hot gas flow. The ratio of the cold gas flow and the hot gas flow can be controlled by adjusting the opening of the regulating valve 36, thereby controlling the ratio of the cold gas flow and the hot gas flow of the vortex tube 30.
[0047] In a possible implementation, the heating area 11 can be connected with the second outlet 351. The high-temperature gas flowing out of the second outlet 351 can enter the heating area 11 of the kiln body 10, thereby heating the heating area 11.
[0048] In a possible implementation, the heating area 11 can include a plurality of heating sections, and the plurality of heating sections are sequentially arranged along the conveying direction. For example, referring to Figure 1 As shown, the plurality of heating sections can sequentially include a temperature rising section 111, a first constant temperature section 112 and a second constant temperature section 113 along the conveying direction, the temperatures in the first constant temperature section 112 and the second constant temperature section 113 are higher than that in the temperature rising section 111, the temperature in the temperature rising section 111 can gradually rise along the conveying direction, and the temperatures in the first constant temperature section 112 and the second constant temperature section 113 remain unchanged.
[0049] In a possible implementation, a first connecting tube 41 is arranged between the first outlet 341 of the vortex tube 30 and the cooling area 12, and a second connecting tube 42 is arranged between the second outlet 351 of the vortex tube 30 and the heating area 11.
[0050] The number of the vortex tubes 30 can be one or multiple.
[0051] For example, referring to Figure 1As shown, when the number of vortex tubes 30 is one, the first outlet 341 of the vortex tube 30 is connected to the cooling zone 12 through the first connecting pipe 41, and the second outlet 351 is connected to one heating section of the heating zone 11 through the second connecting pipe 42. Exemplarily, when the number of vortex tubes 30 is one, the first outlet 341 of the vortex tube 30 is connected to the cooling zone 12 through the first connecting pipe 41, and the second outlet 351 is connected to the temperature-increasing section 111 of the heating zone 11 through the second connecting pipe 42.
[0052] When the number of vortex tubes 30 is multiple, each vortex tube 30 corresponds to one first connecting pipe 41, and the multiple first connecting pipes 41 are connected to the cooling zone 12.
[0053] Exemplarily, referring to Figure 3 As shown, the opening of the end of the first connecting pipe 41 connected to the cooling zone 12 is the outlet of the first connecting pipe 41. When the number of vortex tubes 30 is three, each vortex tube 30 corresponds to one first connecting pipe 41, and the outlets of the three first connecting pipes 41 are sequentially arranged along the conveying direction. In this way, the low-temperature gas in the multiple first connecting pipes 41 can be uniformly distributed in the cooling zone 12, so that the cooling zone 12 can uniformly cool the sintered lithium battery material.
[0054] In a possible implementation, when the number of vortex tubes 30 is multiple, each vortex tube 30 corresponds to one second connecting pipe 42, and the multiple second connecting pipes 42 are connected to at least one heating section of the multiple heating sections.
[0055] In some examples, when the number of vortex tubes 30 is multiple, each vortex tube 30 corresponds to one second connecting pipe 42, and the multiple second connecting pipes 42 are connected to the multiple heating sections, each second connecting pipe 42 corresponding to one heating section. In this way, the high-temperature gas of the multiple second connecting pipes 42 can heat the multiple heating sections of the heating zone 11.
[0056] Exemplarily, referring to Figure 3 As shown, when the number of vortex tubes 30 is three, each vortex tube 30 corresponds to one second connecting pipe 42, and the three second connecting pipes 42 are respectively connected to the temperature-increasing section 111, the first constant-temperature section 112, and the second constant-temperature section 113.
[0057] In a possible implementation, the gas compression device 20 can be a nitrogen compression device. The nitrogen compression device is used to provide compressed nitrogen.
[0058] The nitrogen compression device is provided with a gas outlet pipeline 21. The inlet 311 of the vortex tube 30 and the gas outlet pipeline of the nitrogen compression device are provided with a third connecting pipe 43, and the third connecting pipe 43 is provided with a flow meter 50. The flow meter 50 can measure the inlet flow of the vortex tube 30.
[0059] Exemplarily, compressed nitrogen enters the inlet 311 of the vortex tube 30 from the third connecting pipe 43, low-temperature nitrogen can flow out of the first outlet 341 of the vortex tube 30, the low-temperature nitrogen is introduced into the cooling zone 12 through the first connecting pipe 41, the lithium battery material after sintering in the cooling zone 12 can be provided with nitrogen protection, and the cooling zone 12 can be further cooled, high-temperature nitrogen can flow out of the second outlet 351 of the vortex tube 30, and the heating energy consumption of nitrogen can be reduced.
[0060] The roller kiln of the present application is described in detail below through specific examples. The specific differences of the following roller kiln are shown in Table 1.
[0061] Example 1
[0062] The roller kiln comprises a kiln body 10, a gas compression device 20 and a vortex tube 30. The first connecting pipe 41 connects the first outlet 341 of the vortex tube 30 with the cooling zone 12, and the second connecting pipe 42 connects the second outlet 351 of the vortex tube 30 with the heating zone 11.
[0063] The kiln body 10 has a sagger for carrying lithium battery materials. The weight of the sagger is 8.5 kg. The weight of the lithium battery materials is 572.22 kg.
[0064] The gas compression device 20 provides compressed nitrogen.
[0065] The inlet pressure of the roller kiln is 0.4 Mpa, that is, the inlet pressure of the inlet 311 of the vortex tube 30 is 0.4 Mpa.
[0066] The inlet flow rate of the roller kiln is 40 m 3 / h, that is, the inlet flow rate of the inlet 311 of the vortex tube 30 is 40 m 3 / h.
[0067] The inlet density of the roller kiln is 5.16 kg / m 3 , that is, the inlet density of the inlet 311 of the vortex tube 30 is 5.16 kg / m 3 .
[0068] The inlet mass flow rate of the roller kiln is 206.4 kg / h, that is, the inlet mass flow rate of the inlet 311 of the vortex tube 30 is 206.4 kg / h.
[0069] The inlet mass of the roller kiln is 1065.02 kg, that is, the inlet mass of the inlet 311 of the vortex tube 30 is 1065.02 kg.
[0070] The inlet temperature of the roller kiln is 24℃, that is, the inlet temperature of the inlet 311 of the vortex tube 30 is 24℃.
[0071] The regulating valve 36 of the vortex tube 30 has a nut. The nut can adjust the angle. In the present embodiment, the nut is adjusted at an angle of 45°, i.e. the nut is turned at 45°. The cold flow rate of the vortex tube 30 can be 79.34%, and the hot flow rate can be 20.66%. The unit refrigeration capacity of the vortex tube 30 is 3.66 KJ / kg.
[0072] Example 2
[0073] Example 2 is performed with reference to Example 1, except that the nut is adjusted at an angle of 90°, i.e. the nut is turned at 90°. The cold flow rate of the vortex tube 30 can be 78.26%, and the hot flow rate can be 21.74%. The unit refrigeration capacity of the vortex tube 30 is 9.18 KJ / kg.
[0074] Example 3
[0075] Example 3 is performed with reference to Example 1, except that the nut is adjusted at an angle of 135°, i.e. the nut is turned at 135°. The cold flow rate of the vortex tube 30 can be 60.29%, and the hot flow rate can be 21.74%. The unit refrigeration capacity of the vortex tube 30 is 9.84 KJ / kg.
[0076] Example 4
[0077] Example 4 is performed with reference to Example 1, except that the nut is adjusted at an angle of 180°, i.e. the nut is turned at 180°. The cold flow rate of the vortex tube 30 can be 45%, and the hot flow rate can be 55%. The unit refrigeration capacity of the vortex tube 30 is 8.4 KJ / kg.
[0078] Example 5
[0079] Example 5 is performed with reference to Example 1, except that the nut is adjusted at an angle of 225°, i.e. the nut is turned at 225°. The cold flow rate of the vortex tube 30 can be 27.5%, and the hot flow rate can be 72.5%. The unit refrigeration capacity of the vortex tube 30 is 5.98 KJ / kg.
[0080] Example 6
[0081] Example 6 is performed with reference to Example 1, except that the nut is adjusted at an angle of 270°, i.e. the nut is turned at 270°. The cold flow rate of the vortex tube 30 can be 18.89%, and the hot flow rate can be 81.11%. The unit refrigeration capacity of the vortex tube 30 is 4.68 KJ / kg.
[0082] Example 7
[0083] Example 7 is performed in accordance with Example 1, except that the adjustment angle of the nut is 315°, that is, the nut is rotated 315°. The cold flow rate of the vortex tube 30 can be 15.34%, and the heat flow rate can be 84.66%. The unit cooling capacity of the vortex tube 30 is 4.34 KJ / kg.
[0084] Example 8
[0085] Example 8 is performed in accordance with Example 1, except that the adjustment angle of the nut is 360°, that is, the nut rotates 360°. The cold flow rate of the vortex tube 30 can be 12.27%, and the heat flow rate can be 87.73%. The unit cooling capacity of the vortex tube 30 is 3.9 KJ / kg.
[0086] Example 9
[0087] Example 9 is performed in accordance with Example 1, except that the adjustment angle of the nut is 405°, that is, the nut is rotated 405°. The cold flow rate of the vortex tube 30 can be 3.87%, and the heat flow rate can be 96.13%. The unit cooling capacity of the vortex tube 30 is 1.26 KJ / kg.
[0088] Comparative Example
[0089] The comparative example is the same as in Example 1, except that the roller kiln does not have the vortex tube 30. The air inlet flow rate of the roller kiln is 20 m³ / s. 3 / h, meaning the intake airflow of cooling zone 12 is 20m³ / h. 3 / h, the air intake flow rate of heating zone 11 is 20m³ / h. 3 / h.
[0090] Table 1
[0091]
[0092]
[0093] The relevant performance of the roller kilns in the above embodiments and comparative examples was tested, and the test results are recorded in Table 2. The test methods are as follows:
[0094] The number of times the material temperature can be reduced per hour in the cooling zone: After the material enters the cooling zone, the temperature of the material is measured by a thermocouple thermometer; after cooling in the cooling zone for 10 hours, the temperature of the material is measured again; the difference between the two temperatures is compared with the time to obtain the number of times the material temperature can be reduced per hour.
[0095] Inlet air temperature of the heating zone: The inlet air temperature of the heating zone is measured using a thermocouple thermometer.
[0096] Table 2
[0097]
[0098]
[0099] According to Table 2, compared with the comparative example, the temperature of the material in the cooling zone per hour is increased in the examples 1 to 9, so that the cooling efficiency of the cooling zone 12 after the vortex tube 30 can be improved.
[0100] According to Table 2, compared with the comparative example, the temperature of the material in the cooling zone per hour is increased in the examples 1 to 9, so that the cooling efficiency of the cooling zone 12 after the vortex tube 30 can be improved.
[0101] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not limited to; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A roller hearth kiln characterized by, The kiln body (10) has a cooling zone (12), and the cooling zone (12) is further provided with a cooling structure (13); A gas compression device (20) is arranged outside the kiln body (10), and the gas compression device (20) is used to provide compressed gas; A vortex tube (30) is arranged outside the kiln body (10), and the vortex tube (30) has an inlet (311), a first outlet (341) and a second outlet (351), the inlet (311) is connected with the gas compression device (20), the first outlet (341) is connected with the cooling zone (12), and the first outlet (341) is configured to flow out low-temperature gas. The kiln body (10) further has a heating zone (11), and the heating zone (11) is connected with the second outlet (351); 2. The roller hearth kiln of claim 1, wherein, Wherein, the second outlet (351) is configured to flow out high-temperature gas. A first connecting pipe (41) is arranged between the first outlet (341) of the vortex tube (30) and the cooling zone (12), and a second connecting pipe (42) is arranged between the second outlet (351) of the vortex tube (30) and the heating zone (11).
3. A roller hearth kiln as defined in claim 2, characterized in that The number of the vortex tube (30) is multiple, and each vortex tube (30) corresponds to a first connecting pipe (41), and the outlets of multiple first connecting pipes (41) are arranged in sequence along the conveying direction.
4. A roller hearth kiln as defined in claim 3, characterized in that The heating zone (11) includes multiple heating sections, and multiple heating sections are arranged in sequence along the conveying direction.
5. The roller hearth kiln of claim 3 wherein, Each vortex tube (30) corresponds to a second connecting pipe (42), and multiple second connecting pipes (42) are connected with at least one heating section in multiple heating sections.
6. A roller hearth kiln as defined in claim 5, characterized in that Multiple second connecting pipes (42) are connected with multiple heating sections, and each second connecting pipe (42) corresponds to a heating section.
7. A roller hearth kiln as defined in claim 6, characterized in that The gas compression device (20) is a nitrogen compression device.
8. A roller hearth kiln according to any one of claims 1-7, characterized in that, A third connecting pipe (43) is arranged between the inlet (311) of the vortex tube (30) and the gas outlet pipeline (21) of the nitrogen compression device, and a flow meter (50) is arranged on the third connecting pipe (43).
9. A roller hearth kiln as defined in claim 8, characterized in that, The cooling structure (13) includes multiple connected heat exchange pipes.
10. A roller hearth kiln according to any one of claims 1-6, characterized in that,