A mineral insulated cable metal sheath surface blowing device

Abstract

The application discloses a mineral insulated cable metal sheath surface blowing device, which comprises a fixing frame, a blowing die sleeve and a blowing die core, the blowing die sleeve and the blowing die core are arranged on the fixing frame, the blowing die sleeve and the blowing die core are sleeved and an annular gas distribution channel is formed between the blowing die sleeve and the blowing die core, the blowing die sleeve is connected with an air inlet which is communicated with the gas distribution channel, an air outlet which has a flow converging effect is arranged at the outer end of the gas distribution channel, a flow guide surface which is outwardly flared is arranged at the outer end of the air outlet, and the mineral insulated cable metal sheath passes through the blowing die core, the air outlet and the flow guide surface in sequence. The mineral insulated cable metal sheath surface blowing device has the advantages that the air inlet enters the narrow annular gas distribution channel and forms a certain pressure, then the gas acts on the surface of the metal sheath through the annular air outlet, the water stains and lubricating liquid on the surface of the metal sheath are fully separated, the liquid on the surface of the metal sheath can be effectively removed, the number of blowing pipes is reduced, and the blowing cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of cable air blowing devices, and in particular to an air blowing device for the surface of the metal sheath of a mineral-insulated cable. Background Technology

[0002] In the process of manufacturing the metal sheath of mineral-insulated cables, an argon arc welding longitudinal wrapping and corrugating process is used. After welding, the surface of the metal tube needs to be water-cooled. Before corrugating, a lubricant is needed to protect the metal tube. Before winding the cable onto the coil, the water droplets or lubricant on the surface of the metal tube need to be blown dry. Currently, commonly used air blowing equipment consists of multiple air nozzles in different directions. For example, Chinese patent document CN2024210315312, authorized and announced on December 20, 2024, describes a drying device for cable production and processing, including a processing box, a ring tube, baffles, a winding roller, and a dust removal mechanism. It dries the passing cable by blowing air through a heat pump, an inlet pipe, a ring tube, and an outlet pipe. Several outlet pipes are arranged in an array around the axis of the ring tube. The shortcomings of the existing technology are that the metal tubes have different sizes and specifications, requiring frequent adjustment of the air nozzle positions to ensure air blowing quality, and multiple air nozzles are required. Due to the large number of cable specifications produced, the air nozzle positions are often not adjusted in time, resulting in residual liquid on the surface of the metal tube, which affects subsequent production processes. Therefore, it is clearly necessary to design an annular blowing device that can effectively remove liquid from the surface of the metal tube while reducing the number of blowing tubes and lowering costs. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention provides an air blowing device for the surface of the metal sheath of mineral insulated cables, which improves the air blowing efficiency of the metal tube surface.

[0004] To achieve the above objectives, the present invention adopts the following technical solution.

[0005] An air blowing device for the surface of the metal sheath of a mineral-insulated cable includes a fixed frame, an air blowing mold sleeve, and an air blowing core. The air blowing mold sleeve and the air blowing core are mounted on the fixed frame and are fitted together to form an annular air distribution channel. The air blowing mold sleeve is connected to an air inlet that communicates with the air distribution channel. An air outlet that acts as a concentrator is provided at the outer end of the air distribution channel. The air blowing mold sleeve has an outwardly flared guide surface at the outer end of the air outlet. The metal sheath of the mineral-insulated cable passes through the inside of the air blowing core and sequentially passes through the air outlet and the guide surface.

[0006] Air is introduced into the narrow annular air distribution channel through the air inlet and pressurized. Then, the gas acts on the surface of the metal sheath through the annular air outlet, effectively separating water stains and lubricant from the surface of the metal sheath. This not only effectively eliminates liquid on the surface of the metal sheath but also reduces the number of air blowing tubes and lowers the cost of air blowing.

[0007] Preferably, the blowing mold sleeve and the blowing mold core are relatively movable to adjust the size of the air outlet. This allows the blowing device to handle metal sleeves of different outer diameters. When the outer diameter of the metal sleeve is large, more liquid accumulates on the surface. In addition to ensuring sufficient pressure, a large air flow rate is also required to effectively remove the liquid. Therefore, the air outlet can be adjusted to a larger size, while simultaneously increasing the airflow velocity at the inlet. When the outer diameter of the metal sleeve is small, the amount of liquid accumulated on the surface is small. Generally, maintaining a higher air pressure is sufficient to remove liquid from the surface. Therefore, the air outlet can be adjusted to a smaller size, reducing the amount of compressed air used and lowering costs.

[0008] Preferably, the blowing mold sleeve includes a sleeve body, inside which, along the moving direction of the metal sheath, are sequentially provided a mounting hole, a first air outlet surface, and a guide surface. The blowing mold core includes a core body, outside which, along the moving direction of the metal sheath, are sequentially provided a connecting surface, an air distribution surface, and a second air outlet surface. A sealing surface is provided between the connecting surface and the air distribution surface. The connecting surface and the mounting hole cooperate, and the sealing surface, the air distribution surface, and the mounting hole form an air distribution channel. The first air outlet surface and the second air outlet surface are arranged opposite to each other to form an annular air outlet. This achieves reliable forming of the annular air distribution channel and the annular air outlet.

[0009] Preferably, the air-blowing mold sleeve further includes a first connecting section, and the air-blowing mold core further includes a second connecting section. The first connecting section, the second connecting section, and the fixing frame are connected. The first connecting section and the second connecting section ensure reliable positioning of the air-blowing mold sleeve and the air-blowing mold core relative to the fixing frame.

[0010] Preferably, the fixing frame is equipped with a connecting rod. The first connecting section is fixedly connected to the connecting rod, and the second connecting section is slidably connected to the connecting rod. The blowing mold core is fitted with fasteners that connect to the blowing mold sleeve or the connecting rod. After the second connecting section is slidably adjusted along the connecting rod, the size of the air outlet can be reliably adjusted by locking it with the fasteners.

[0011] Preferably, a main scale is connected between the fixing frame and the first connecting section. The second connecting section has an opening slot that exposes the main scale, and a vernier caliper is installed in the opening slot. The fasteners are bolts that connect the air-blowing mold core and the air-blowing mold sleeve. The vernier caliper, in conjunction with the main scale, can accurately measure the amount of movement of the second connecting section relative to the first connecting section, achieving reliable control of the position of the second connecting section, i.e., precise control of the air outlet size, which facilitates synchronous adjustment of the air outlet size as the metal sheath changes.

[0012] Preferably, the first outlet surface is a cone with its cone angle pointing towards the direction of the metal sheath's movement, and the guide surface is also a cone with its cone angle pointing in the opposite direction to that of the first outlet surface. The cone angle of the first outlet surface corresponds to the cavity enclosed by the guide surface. After the gas flowing out of the outlet dries the surface of the metal sheath, it carries liquid into the guide surface and guides it out of the blown sheath, causing liquid accumulation on the surface of the metal sheath and affecting the efficiency of the blowing device.

[0013] Preferably, the blowing die sleeve is provided with several air inlets, and the airflow direction of the air inlets corresponds to the second air outlet surface or air distribution surface. Multiple air inlets work together to introduce air, and with the flow guiding or air distribution channel of the second air outlet surface and the air outlet convergence effect, reliable annular air outlet is achieved, ensuring that the liquid is blown around the metal sheath without dead angles, and ensuring the blowing efficiency.

[0014] Preferably, the second air outlet surface is conical, and the direction of the conical angle of the second air outlet surface is the same as that of the first air outlet surface. The conical angle of the second air outlet surface is smaller than that of the first air outlet surface to give the air outlet a converging effect. When the first connecting section and the second connecting section abut, a gap is maintained between the first air outlet surface and the second air outlet surface to ensure unobstructed airflow at the air outlet. The air outlet has a good converging effect on the incoming air, and the airflow is smooth and stable during discharge, achieving full blowing. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of an air blowing device for the surface of the metal sheath of a mineral-insulated cable, as disclosed in one embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of a surface air blowing device for the metal sheath of a mineral-insulated cable, as disclosed in another embodiment of the present invention.

[0017] Figure 3 yes Figure 2 The illustrated embodiment is a schematic diagram showing the connection between the air-blowing mold core, air-blowing mold sleeve, and fixing frame when the first connecting section and the second connecting section abut.

[0018] Figure 4 This is a schematic diagram of the external structure of an air blowing device for the surface of the metal sheath of a mineral-insulated cable, as disclosed in one embodiment of the present invention.

[0019] In the diagram: Fixing frame 1, connecting rod 11; 2. Inflatable sleeve; 21. First connecting section; 22. Mounting hole; 23. First air outlet surface; 24. Guide surface; Inflatable mold core 3, second connecting section 31, connecting surface 32, air distribution surface 33, second air outlet surface 34, sealing surface 35; Air distribution channel 4, air inlet 41, air outlet 42, fastener 43, main scale 44, opening groove 45, vernier scale 46. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] The terms “comprising” and “having”, and any variations thereof, used in the specification and claims of this invention are intended to cover a non-exclusive inclusion, such as a method or product that includes a series of technical features, not necessarily limited to those technical features explicitly listed, but may also include other technical features that may be included in the method or product but not explicitly listed.

[0022] In the description of this invention, it should be understood that the technical features defined by terms such as "first" and "second" which have a sequential concept are only used to clearly describe the defined technical features and to clearly distinguish the defined technical features from other technical features, and do not represent that they are named in this way in actual implementation. Therefore, they should not be construed as limitations on this invention.

[0023] Example 1 like Figures 1 to 4 As shown, an air blowing device for the surface of the metal sheath of a mineral-insulated cable includes a fixed frame 1, an air blowing mold sleeve 2, and an air blowing core 3. The air blowing mold sleeve 2 and the air blowing core 3 are mounted on the fixed frame 1. The air blowing mold sleeve 2 and the air blowing core 3 are fitted together, forming an annular air distribution channel 4 between them. The air blowing mold sleeve 2 is connected to an air inlet 41 that communicates with the air distribution channel 4. The outer end of the air distribution channel 4 is provided with an air outlet 42 that serves to concentrate the airflow. The air blowing mold sleeve 2 is provided with an outwardly flared guide surface 24 at the outer end of the air outlet 42. The metal sheath of the mineral-insulated cable passes through the inside of the air blowing core 3 and sequentially passes through the air outlet 42 and the guide surface 24.

[0024] In the process of manufacturing the metal sheath of mineral-insulated cables, an argon arc welding longitudinal wrapping and corrugating process is used. After welding, the surface of the metal tube needs to be water-cooled. Before corrugating, lubricant is needed to protect the metal tube. Before winding the cable onto the coil, the water droplets or lubricant on the surface of the metal tube need to be dried. The fixing frame 1 is fixed at the outlet of the corrugating equipment. After the metal sheath exits from the outlet of the corrugating equipment, it first passes through the through hole in the fixing frame 1, then through the through hole inside the air blowing mold core 3, and then sequentially through the air outlet 42 and the guide surface 24. As the metal sheath moves outward, air enters through the air inlet 41. The air blowing mold sleeve 2 is fitted onto the outside of one end of the air blowing mold core 3. The air distribution channel 4 and the air outlet 42 are formed between the air outlet mold sleeve and the air blowing mold core 3. The air inlet 41, the air distribution channel 4, and the air outlet 42 are connected. The compressed air entering through the air inlet 41 enters the narrow annular air distribution channel 4 and forms a certain pressure. Then, the gas acts on the surface of the metal sheath through the annular air outlet 42, which fully separates the water stains and lubricant on the surface of the metal sheath. This can effectively eliminate the liquid on the surface of the metal sheath, while reducing the number of air blowing pipes and reducing the cost of air blowing.

[0025] Example 2 An air blowing device for the surface of the metal sheath of a mineral-insulated cable, such as Figure 1 As shown, the device includes a fixed frame 1, an air-blowing mold sleeve 2, and an air-blowing mold core 3. The air-blowing mold sleeve 2 and the air-blowing mold core 3 are mounted on the fixed frame 1. The air-blowing mold sleeve 2 and the air-blowing mold core 3 are fitted together, forming an annular air distribution channel 4 between them. The air-blowing mold sleeve 2 is connected to an air inlet 41 that communicates with the air distribution channel 4. The outer end of the air distribution channel 4 is provided with an air outlet 42 that serves to concentrate the airflow. The air-blowing mold sleeve 2 is provided with an outwardly flared guide surface 24 at the outer end of the air outlet 42. The metal sheath of the mineral-insulated cable passes through the inside of the air-blowing mold core 3 and passes through the air outlet 42 and the guide surface 24 in sequence. The blowing mold sleeve 2 includes a sleeve body. Inside the sleeve body, along the moving direction of the metal sheath, are sequentially arranged mounting holes 22, a first air outlet surface 23, and a guide surface 24. The blowing mold core 3 includes a core body. Outside the core body, along the moving direction of the metal sheath, are sequentially arranged connecting surfaces 32, air distribution surfaces 33, and a second air outlet surface 34. A sealing surface 35 is formed between the connecting surface 32 and the air distribution surface 33. The connecting surface 32 and the mounting hole 22 are interference-fitted to form a seal. The sealing surface 35, the air distribution surface 33, and the mounting hole 22 form an air distribution channel 4. The first air outlet surface 23 and the second air outlet surface 34 are arranged opposite each other to form an annular air outlet 42. The connecting surface 32 and the air distribution surface 33 are coaxial cylindrical surfaces, with the diameter of the connecting surface 32 being larger than that of the air distribution surface 33. The sealing surface 35 is an annular surface.

[0026] The air-blowing sleeve 2 is provided with several air inlets 41, and the airflow direction of the air inlets 41 corresponds to the second air outlet surface 34. Multiple air inlets 41 work together to introduce air, and with the guidance of the second air outlet surface 34, reliable annular air outlet 42 is achieved, ensuring that the liquid is blown around the metal sleeve without dead angles, and ensuring the blowing efficiency.

[0027] The air-blowing mold sleeve 2 also includes a first connecting section 21, and the air-blowing mold core 3 also includes a second connecting section 31. The first connecting section 21, the second connecting section 31, and the fixing frame 1 are fastened together by bolts and through holes. The first connecting section 21 and the second connecting section 31 ensure that the air-blowing mold sleeve 2 and the air-blowing mold core 3 are reliably positioned relative to the fixing frame 1.

[0028] The first outlet surface 23 is a cone with its cone angle pointing towards the direction of the metal sheath's movement. The guide surface 24 is also a cone, and the cone angle of the guide surface 24 is opposite to that of the first outlet surface 23. The cone angle of the first outlet surface 23 corresponds to the cavity enclosed by the guide surface 24. After the gas flowing out of the outlet 42 dries the surface of the metal sheath, it carries liquid into the guide surface 24 and guides it out of the blown sheath, causing liquid to accumulate on the surface of the metal sheath and affecting the efficiency of the blowing device.

[0029] Example 3 An air blowing device for the surface of the metal sheath of a mineral-insulated cable, such as Figure 2 and Figure 4 As shown, the device includes a fixed frame 1, an air-blowing mold sleeve 2, and an air-blowing mold core 3. The air-blowing mold sleeve 2 and the air-blowing mold core 3 are mounted on the fixed frame 1. The air-blowing mold sleeve 2 and the air-blowing mold core 3 are fitted together, forming an annular air distribution channel 4 between them. The air-blowing mold sleeve 2 is connected to an air inlet 41 that communicates with the air distribution channel 4. The outer end of the air distribution channel 4 is provided with an air outlet 42 that serves to concentrate the airflow. The air-blowing mold sleeve 2 is provided with an outwardly flared guide surface 24 at the outer end of the air outlet 42. The metal sheath of the mineral-insulated cable passes through the inside of the air-blowing mold core 3 and passes through the air outlet 42 and the guide surface 24 in sequence. The blowing mold sleeve 2 includes a sleeve body. Inside the sleeve body, along the moving direction of the metal sheath, there are sequentially arranged mounting holes 22, a first air outlet surface 23, and a guide surface 24. The blowing mold core 3 includes a core body. On the outer side of the core body, along the moving direction of the metal sheath, there are sequentially arranged connecting surfaces 32, air distribution surfaces 33, and a second air outlet surface 34. A sealing surface 35 is provided between the connecting surface 32 and the air distribution surface 33. The connecting surface 32 and the mounting hole 22 cooperate with each other. The sealing surface 35, the air distribution surface 33, and the mounting hole 22 form an air distribution channel 4. The first air outlet surface 23 and the second air outlet surface 34 are arranged opposite to each other and form an annular air outlet 42.

[0030] The air-blowing mold sleeve 2 is provided with several air inlets 41, such as... Figure 2 In the indicated state, the airflow direction at the air inlet 41 corresponds to the second air outlet 34. In the... Figure 3 In the indicated state, the airflow direction of the air inlet corresponds to the air distribution surface 33. Multiple air inlets 41 work together to intake air, and with the guidance of the second air outlet surface 34, reliable annular air outlet 42 is achieved, ensuring that the liquid is blown around the metal sheath without dead angles, thus ensuring the blowing efficiency.

[0031] The air-blowing mold sleeve 2 also includes a first connecting section 21, and the air-blowing mold core 3 also includes a second connecting section 31. The first connecting section 21 is fixedly connected to the fixing frame 1, and the second connecting section 31 is slidably connected to the fixing frame 1. The first air outlet surface 23 is a conical surface with its cone angle pointing towards the direction of the metal sheath's movement. The guide surface 24 is a conical surface, and the cone angle of the guide surface 24 is opposite to the cone angle of the first air outlet surface 23. The cone angle of the first air outlet surface 23 corresponds to the cavity enclosed by the guide surface 24.

[0032] The blowing mold sleeve 2 and the blowing mold core 3 are relatively movable to adjust the size of the air outlet 42. Specifically, the fixed frame 1 is provided with a connecting rod 11. The first connecting section 21 is fixedly connected to the connecting rod 11, and the second connecting section 31 is slidably connected to the connecting rod 11. The blowing mold core 3 is equipped with a fastener 43 that connects the blowing mold sleeve 2 or the connecting rod 11. After the second connecting section 31 is slidably adjusted along the connecting rod 11, it can be locked with the fastener 43 to reliably adjust the size of the air outlet 42. This allows the blowing device to handle metal sleeves of different outer diameters. When the outer diameter of the metal sleeve is large, more liquid accumulates on the surface. In addition to ensuring pressure, a large gas flow rate is also required to fully remove the liquid. Therefore, the air outlet 42 can be adjusted to a larger size. Figure 2 The illustrated scheme simultaneously enhances the airflow velocity at the inlet 41. When the outer diameter of the metal sheath is small, the amount of liquid accumulating on the surface is small, and surface dehydration can usually be achieved by maintaining a relatively high air pressure. Therefore, the outlet 42 can be adjusted to a smaller size. Figure 3 The scheme shown can reduce compressed air consumption and lower costs. The second outlet surface 34 is conical, and the cone angle of the second outlet surface 34 faces the same direction as the cone angle of the first outlet surface 23. The cone angle of the second outlet surface 34 is smaller than that of the first outlet surface 23 so that the outlet 42 has a converging effect. When the first connecting section 21 and the second connecting section 31 come into contact, it is at... Figure 3 In the indicated state, a gap is maintained between the first air outlet surface 23 and the second air outlet surface 34 to ensure that the air outlet 42 is unobstructed. The air outlet 42 has a good converging effect on the incoming air, and the air outlet has high stability and smooth flow, achieving full blowing.

[0033] As a simple replacement for the above scheme, both the first air outlet surface 23 and the second air outlet surface 34 are spherical surfaces, and the diameter of the first air outlet surface 23 is larger than that of the second air outlet surface 34. The first air outlet surface 23 is located in the spherical surface corresponding to the first air outlet surface 23, thus obtaining an air outlet 42 that also has a flow-gathering effect.

[0034] Example 4 An air blowing device for the surface of the metal sheath of a mineral-insulated cable, such as Figure 4As shown, the difference between Embodiment 4 and Embodiment 3 lies only in that a main ruler 44 is connected between the fixing frame 1 and the first connecting section 21, and an opening groove 45 is provided on the second connecting section 31 to expose the main ruler 44. A vernier caliper 46 is provided in the opening groove 45, which slides relative to the main ruler 44. Fasteners 43 are bolts connecting the air-blowing mold core 3 and the air-blowing mold sleeve 2. The vernier caliper 46, in conjunction with the main ruler 44, can accurately measure the movement of the second connecting section 31 relative to the first connecting section 21, achieving reliable control of the position of the second connecting section 31, i.e., precise control of the size of the air outlet 42, facilitating synchronous changes in the size of the air outlet 42 as the metal sheath changes.

[0035] In the scheme disclosed in this embodiment, the maximum diameter of the metal sheath does not exceed the inner diameter of the air blowing core. The size of the air outlet 42 corresponds to the gap between the ends of the first air outlet surface 23 and the second air outlet surface 34, with a gap range of 2 to 7 millimeters. According to the specifications of the metal sheath, the size of the air outlet 42 is adaptively divided into corresponding levels. By adjusting the distance of the corresponding vernier scale 46 reading for the corresponding level, the accurate corresponding adjustment of the size of the air outlet 42 can be achieved.

Claims

1. An air blowing device for the surface of the metal sheath of a mineral-insulated cable, characterized in that, It includes a fixed frame, an air-blowing mold sleeve, and an air-blowing mold core. The air-blowing mold sleeve and the air-blowing mold core are mounted on the fixed frame and are fitted together to form an annular air distribution channel. The air-blowing mold sleeve is connected to an air inlet that communicates with the air distribution channel. The outer end of the air distribution channel is provided with an air outlet that serves to concentrate the airflow. The air-blowing mold sleeve is provided with an outwardly flared guide surface at the outer end of the air outlet. The metal sheath of the mineral-insulated cable passes through the inside of the air-blowing mold core and passes through the air outlet and the guide surface in sequence.

2. The air blowing device for the surface of the metal sheath of a mineral-insulated cable according to claim 1, characterized in that, The air blowing mold sleeve and air blowing mold core are relatively movable to adjust the size of the air outlet.

3. The air blowing device for the surface of the metal sheath of a mineral-insulated cable according to claim 1, characterized in that, The blowing mold sleeve includes a sleeve body. Inside the sleeve body, along the moving direction of the metal sheath, there are sequentially arranged mounting holes, a first air outlet surface, and a guide surface. The blowing mold core includes a core body. Outside the core body, along the moving direction of the metal sheath, there are sequentially arranged connecting surfaces, air distribution surfaces, and a second air outlet surface. There is a sealing surface between the connecting surface and the air distribution surface. The connecting surface and the mounting hole cooperate with each other. The sealing surface, the air distribution surface, and the mounting hole form an air distribution channel. The first air outlet surface and the second air outlet surface are arranged opposite each other to form an annular air outlet.

4. A surface air blowing device for the metal sheath of a mineral-insulated cable according to any one of claims 1 to 3, characterized in that, The air-blowing mold sleeve includes a first connecting section, and the air-blowing mold core includes a second connecting section. The first connecting section, the second connecting section, and the fixing frame are connected.

5. The air blowing device for the surface of the metal sheath of a mineral-insulated cable according to claim 4, characterized in that, The fixed frame is provided with a connecting rod. The first connecting section is fixedly connected to the connecting rod, and the second connecting section is slidably connected to the connecting rod. The blowing mold core is fitted with fasteners that connect the blowing mold sleeve or the connecting rod.

6. The air blowing device for the surface of the metal sheath of a mineral-insulated cable according to claim 5, characterized in that, A main ruler is connected between the fixed frame and the first connecting section. The second connecting section has an opening groove that exposes the main ruler. A vernier scale is provided in the opening groove. The fasteners are fastening bolts that connect the air blowing mold core and the air blowing mold sleeve.

7. The air blowing device for the surface of the metal sheath of a mineral-insulated cable according to claim 3, characterized in that, The first air outlet surface is a cone surface with its cone angle pointing towards the direction of the metal sheath's movement out. The guide surface is a cone surface, and the cone angle of the guide surface is opposite to the cone angle of the first air outlet surface. The cone angle of the first air outlet surface corresponds to the cavity enclosed by the guide surface.

8. The air blowing device for the surface of the metal sheath of a mineral-insulated cable according to claim 3, characterized in that, The blowing mold sleeve is provided with several air inlets, and the airflow direction of the air inlets corresponds to the second air outlet surface or air distribution surface.

9. An air-blowing device for the surface of the metal sheath of a mineral-insulated cable according to claim 3, 7, or 8, characterized in that, The second air outlet surface is a cone angle and the cone angle of the second air outlet surface is oriented in the same direction as the cone angle of the first air outlet surface. The cone angle of the second air outlet surface is smaller than the cone angle of the first air outlet surface so that the air outlet has a flow-gathering effect. When the first connecting section and the second connecting section abut, a gap is maintained between the first air outlet surface and the second air outlet surface to ensure that the air outlet is unobstructed.

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