Explosion-proof corrosion-resistant fan

Abstract

The invention relates to an anti-explosion corrosion-resistant fan, which belongs to the field of fans, and comprises a mounting shell, a separation plate is mounted in the mounting shell, a disc type stator is mounted in the mounting shell, an impeller is rotatably arranged on the separation plate, the disc type stator and the impeller are positioned on two sides of the separation plate, and a separation piece and a disc type rotor are arranged on one side, facing the disc type stator, of the impeller. The isolation plate is used for forming physical isolation between the disc-type stator and the impeller and between the disc-type rotor and sucked-in gas, the isolation piece is used for preventing the sucked-in gas from entering the rotating connection position of the impeller, an air inlet is formed in the top face of the mounting shell, an air outlet is formed in the side face of the mounting shell, and an air supply channel is formed in the mounting shell in the circumferential direction of the mounting shell. The anti-explosion and anti-corrosion fan has the effects of shortening the axial space and enhancing the anti-explosion and anti-corrosion protection performance of the fan.

Description

Technical Field

[0001] This application relates to the field of wind turbine technology, and in particular to an explosion-proof and corrosion-resistant wind turbine. Background Technology

[0002] A fan is a machine that relies on a power unit to drive an impeller to rotate, increase gas pressure, and drive the directional transport of gas. It belongs to a type of driven fluid machinery and is widely used in industrial ventilation, medical equipment, new energy, and other scenarios involving directional gas flow.

[0003] Currently, most wind turbine structures consist of a fluid module and a motor module. The motor module mainly consists of a rotor axially nested with a stator, which occupies a large axial space, limiting its application in some small hydrogen energy and integrated equipment. There is a lack of effective physical isolation between the motor module and the fluid module. Contaminants and corrosive gases in the fluid can directly contact the motor module and internal bearings, directly interfering with the motor module's drive operation. Furthermore, it can easily corrode the internal bearings, damaging their lubrication performance and causing bearing failure. At the same time, the grease on the bearings can contaminate the gas in the main flow channel, making the discharged gas unusable. In special scenarios such as explosion-proof and hydrogen-resistant environments, there is even a risk of safety accidents caused by sparks generated when the gas comes into contact with the motor module. Summary of the Invention

[0004] In order to shorten the axial space and enhance the explosion-proof and corrosion-resistant protection of the fan, this application provides an explosion-proof and corrosion-resistant fan.

[0005] This application provides an explosion-proof and corrosion-resistant fan. The technical solution adopted is as follows: An explosion-proof and corrosion-resistant fan includes a mounting housing, an isolation plate installed inside the mounting housing, a disc stator installed inside the mounting housing, an impeller rotatably mounted on the isolation plate, the disc stator and the impeller located on opposite sides of the isolation plate, an isolation element and a disc rotor provided on the side of the impeller facing the disc stator, the isolation plate being used to physically isolate the disc stator from the impeller, the disc rotor and the drawn-in gas, the isolation element being used to prevent the drawn-in gas from entering the rotating connection of the impeller, an air inlet being provided on the top surface of the mounting housing, an air outlet being provided on the side of the mounting housing, and an air supply channel being provided circumferentially inside the mounting housing.

[0006] By adopting the above technical solution, dual physical isolation of the disc stator and impeller, and bearings and disc rotor is achieved simultaneously. The isolation plate blocks the possibility of flammable and explosive gases coming into contact with the stator, avoids the risk of explosion caused by the encounter of sparks and gases, and the isolation component prevents corrosive gases from directly contacting the bearings and causing damage to the components. It also prevents grease on the bearings from contaminating the transported gas, thus achieving bidirectional isolation protection between the gas and the bearings and enhancing the corrosion resistance and protection of the fan.

[0007] Optionally, a cylindrical protrusion is fixedly provided on the isolation plate, the cylindrical protrusion is positioned facing the impeller, a bearing is fixedly provided inside the cylindrical protrusion, a rotating shaft is rotatably provided on the bearing, and the rotating shaft is fixedly connected to the impeller.

[0008] By adopting the above technical solution, the cylindrical protrusion plays a fixing role for the bearing, enhancing the bearing's stable support for the rotating shaft, and the isolating part sleeved on the outside of the cylindrical protrusion plays a guiding role in the installation of the impeller.

[0009] Optionally, a plurality of first blades and a plurality of second blades are fixedly arranged on the side of the impeller facing the air inlet. The first blades and second blades are arranged alternately. One end of the first blade is located near the central axis of the side of the impeller facing the air inlet, and the other end of the first blade is flush with the circumferential surface of the impeller. One end of the second blade is flush with the circumferential surface of the impeller, and the other end of the second blade is located at one-third to one-half of the length of the first blade.

[0010] By adopting the above technical solution, the formation of eddies in the impeller area of ​​the drawn-in gas can be effectively suppressed. The first and second blades can guide the gas to be transported smoothly, while reducing the gas stagnation inside the fan, avoiding the formation of local airflow dead zones, and improving the efficiency and stability of fluid transport.

[0011] Optionally, the isolation element includes an isolation sleeve fixed to the side of the impeller facing the isolation plate, the isolation sleeve covering the cylindrical protrusion, and the isolation sleeve supported on the isolation plate.

[0012] By adopting the above technical solution, the bearing is located inside the cylindrical protrusion and the isolation sleeve, which protect the bearing and prevent gas, dust and other substances from entering the bearing chamber and interfering with the bearing operation.

[0013] Optionally, the isolation sleeve is provided with a plurality of third blades along its circumference. The third blades are located on the side of the isolation sleeve opposite to the cylindrical protrusion, and the rotation direction of the third blades is opposite to that of the first blades and the second blades.

[0014] By adopting the above technical solution, when the third blade rotates synchronously with the impeller, a stable protective flow field can be formed. The flow field can block the gas between the mounting shells from entering the bearing chamber from the back of the impeller. The flow field isolation effect prevents corrosive gases from directly contacting the bearing and causing component damage. At the same time, it prevents grease on the bearing from contaminating the transported gas, thus achieving the function of isolation and protection for the bearing.

[0015] Optionally, the impeller is further provided with an annular protrusion on the side facing the isolation plate. The annular protrusion is coaxially arranged with the impeller. Several connecting blocks are fixedly connected to the annular protrusion along its outer circumferential surface. A positioning block is fixedly connected to the connecting block. The positioning block is located between the isolation sleeve and the cylindrical protrusion. The positioning block is fitted to the outer circumference of the cylindrical protrusion.

[0016] By adopting the above technical solution, the fixing block limits the impeller to the cylindrical protrusion, preventing the impeller from shifting when rotating, and ensuring that the impeller is always coaxially connected with the cylindrical protrusion and the isolation plate.

[0017] Optionally, the disc rotor is embedded in the side of the impeller facing away from the air inlet. The disc rotor is a ring-shaped permanent magnet. The isolation sleeve passes through the disc rotor. The disc stator, the disc rotor, and the cylindrical protrusion are all coaxially arranged with the rotation axis.

[0018] By adopting the above technical solution, the disc rotor can be embedded in the impeller to directly drive the impeller to rotate, improve the efficiency of force transmission, reduce energy loss, and make the structure of the fan more compact and flat, thereby reducing the axial space of the fan. At the same time, the disc rotor is an integral ring permanent magnet structure, which can stably withstand high-speed centrifugal force by its own strength, avoid generating unilateral axial magnetic pull, and better adapt to high-speed operation.

[0019] Optionally, the mounting housing includes an upper shroud and a lower shroud, the air inlet is formed on the upper shroud, the upper shroud and the lower shroud together form a volute-like structure, and the air outlet is formed at the port of the upper shroud and the lower shroud.

[0020] By adopting the above technical solution, the upper and lower shrouds work together to form a volute-like structure to protect the internal equipment of the fan. At the same time, the upper shroud allows air to enter from the middle and exit from the sides through the centrifugal force generated by the first and second blades. This ensures that the gas enters evenly and is then discharged in an orderly manner. Furthermore, the volute-like structure can reduce noise during the high-speed operation of the fan.

[0021] Optionally, one side of the disc stator is fitted with the inner wall of the lower hood, the other side of the disc stator is fitted with the isolation plate, and the side of the isolation plate is fitted with the inner wall of the lower hood.

[0022] By adopting the above technical solution, the upper and lower surfaces of the disc stator are respectively attached to the isolation plate and the lower shroud, which can quickly transfer the generated heat to the isolation plate and the lower shroud. The drawn-in internal flowing gas and external air can promptly remove the heat from the surface of the isolation plate and the lower shroud, thereby improving heat dissipation efficiency and ensuring the safe operation of the fan.

[0023] Optionally, an annular fixing plate is fixedly provided on the side of the impeller facing the isolation plate. Several arc-shaped cover plates are hinged to the annular fixing plate. Both ends of the arc-shaped cover plates are hinged to fan-shaped plates. Adjacent fan-shaped plates are hinged together. The arc-shaped cover plates and the fan-shaped plates are located between the third blade and the disc rotor. When the impeller is stationary, the fan-shaped plates fold inward toward the third blade. The arc-shaped cover plates are perpendicular to the isolation plate. Several arc-shaped cover plates together surround the third blade. When the impeller rotates, the fan-shaped plates unfold. The fan-shaped plates and the arc-shaped cover plates form a ring structure. The fan-shaped plates and the arc-shaped cover plates are in contact with the side of the impeller facing the isolation plate.

[0024] By adopting the above technical solution, when the fan stops running, the arc-shaped cover and the fan-shaped plate are subjected to gravity, causing the fan-shaped plate to fold inward. The arc-shaped cover and the fan-shaped plate are perpendicular to the partition plate and in contact with the partition plate. At this time, the arc-shaped cover, the partition plate and the impeller form a physical isolation to protect the internal components such as the bearings. When the fan is running, the arc-shaped cover and the fan-shaped plate are subjected to centrifugal force, causing the fan-shaped plate to unfold. The arc-shaped cover and the fan-shaped plate are parallel to the partition plate and are in contact with the impeller. At this time, the flow field generated by the rotation of the third blade provides a path for the gas to move to the air supply channel, ensuring that the grease in the bearing will not contaminate the purity of the gas discharged from the fan, and that corrosive gases will not affect the internal equipment such as the bearings.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. It simultaneously achieves dual physical isolation of the disc stator and bearings. The isolation plate blocks the possibility of flammable and explosive gases coming into contact with the stator, avoiding the risk of explosion caused by the encounter of sparks and gases. The isolation component prevents corrosive gases from directly contacting the bearings and causing damage to the components, and prevents grease on the bearings from contaminating the transported gas. It achieves bidirectional isolation protection between the gas and the bearings, and enhances the corrosion resistance and protection of the fan.

[0026] 2. The disc rotor is embedded in the impeller and can directly drive the impeller to rotate, which improves the efficiency of force transmission, reduces energy loss, and makes the structure of the fan more compact and flat, thereby reducing the axial space of the fan. At the same time, the disc rotor is an integral ring permanent magnet structure, which can stably withstand high-speed centrifugal force by its own strength, avoiding the generation of unilateral axial magnetic pull, and is better suited to high-speed operation.

[0027] 3. The second blade can effectively suppress the formation of vortices in the impeller area of ​​the drawn-in gas. The first and second blades can guide the gas to be transported smoothly, while reducing the gas stagnation inside the fan, avoiding the formation of local airflow dead zones, and improving the efficiency and stability of fluid transport. When the third blade rotates synchronously with the impeller, it can form a stable protective flow field. The flow field can block the gas between the mounting shells from entering the bearing chamber from the back of the impeller. The flow field isolation effect prevents corrosive gases from directly contacting the bearing and causing component damage, while preventing grease on the bearing from contaminating the transported gas, thus achieving the isolation and protection of the bearing.

[0028] 4. The upper and lower surfaces of the disc stator are respectively attached to the isolation plate and the lower shroud, which can quickly transfer the generated heat to the isolation plate and the lower shroud. The drawn-in internal flowing gas and external air can promptly remove the heat from the surface of the isolation plate and the lower shroud, improving heat dissipation efficiency and ensuring the safe operation of the fan.

[0029] 5. When the fan stops running, the arc-shaped cover and the fan-shaped plate fold inward due to gravity. The arc-shaped cover and the fan-shaped plate are perpendicular to the isolation plate and in contact with it. At this time, the arc-shaped cover, the isolation plate and the impeller form a physical isolation to protect the internal components such as the bearings. When the fan is running, the arc-shaped cover and the fan-shaped plate are subjected to centrifugal force. The fan-shaped plate unfolds and the arc-shaped cover and the fan-shaped plate are parallel to the isolation plate and are in contact with the impeller. At this time, the flow field generated by the rotation of the third blade provides a path for the gas to move to the air supply channel, ensuring that the grease in the bearing will not contaminate the purity of the gas discharged by the fan, and that corrosive gases will not affect the internal equipment such as the bearings. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this application.

[0031] Figure 2 This is a cross-sectional schematic diagram of the overall structure of Embodiment 1 of this application.

[0032] Figure 3 This is a schematic diagram of the structure of the isolation component used in Embodiment 1 of this application.

[0033] Figure 4 This is a cross-sectional structural diagram of Embodiment 1 of this application, used to illustrate the rear end cover.

[0034] Figure 5 This is a cross-sectional structural diagram of Embodiment 2 of this application, illustrating the folding of the arc-shaped cover plate and the fan-shaped plate.

[0035] Figure 6 This is a cross-sectional structural diagram of Embodiment 2 of this application, illustrating the unfolding of the arc-shaped cover plate and the fan-shaped plate.

[0036] Explanation of reference numerals in the attached drawings: 1. Mounting housing; 11. Air inlet; 12. Air outlet; 13. Air supply duct; 14. Upper hood; 15. Lower hood; 151. Receiving groove; 16. Rear end cover; 2. Isolation plate; 21. Cylindrical protrusion; 4. Disc stator; 5. Impeller; 511. First blade; 512. Second blade; 52. Isolation component; 521. Isolation sleeve; 522. Third blade; 523. Annular fixing plate; 524. Arc-shaped cover plate; 525. Fan-shaped plate; 531. Annular protrusion; 532. Connecting block; 533. Positioning block; 6. Disc rotor; 7. Bearing; 8. Rotating shaft; 81. Fixing protrusion. Detailed Implementation

[0037] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0038] Example 1 This application discloses an explosion-proof and corrosion-resistant fan.

[0039] like Figure 1 The explosion-proof and corrosion-resistant fan includes a mounting shell 1, which has a volute-shaped structure. The mounting shell 1 includes an upper hood 14 and a lower hood 15. A circular air inlet 11 is provided at the middle of the top of the upper hood 14. The sides of the upper hood 14 and the lower hood 15 together form an air supply channel 13. The ports of the upper hood 14 and the lower hood 15 together form an air outlet 12. A circular receiving groove 151 is provided at the bottom of the lower hood 15.

[0040] like Figure 1 and Figure 2 An isolation plate 2 is installed inside the receiving groove 151. The isolation plate 2 is made of a high thermal conductivity material. The diameter of the isolation plate 2 is the same as the diameter of the receiving groove 151. The top surface of the isolation plate 2 is flush with the upper edge of the groove opening of the receiving groove 151. The side of the isolation plate 2 is in contact with the inner wall of the receiving groove 151. A disc stator 4 is provided between the isolation plate 2 and the lower hood 15. The disc stator 4 has a coreless structure. The diameter of the disc stator 4 is smaller than the diameter of the isolation plate 2. The top surface of the disc stator 4 is in contact with the bottom surface of the isolation plate 2, and the bottom surface of the disc stator 4 is in contact with the bottom surface of the receiving groove 151. A cylindrical protrusion 21 is fixedly provided on the top surface of the isolation plate 2. The isolation plate 2 and the cylindrical protrusion 21 are integrally formed. A bearing 7 is fixedly provided inside the cylindrical protrusion 21. A rotating shaft 8 is rotatably provided inside the bearing 7. A fixed protrusion 81 is provided on one end of the rotating shaft 8 that extends into the cylindrical protrusion 21. The rotating shaft 8 and the fixed protrusion 81 are integrally formed. An impeller 5 is rotatably mounted on the isolation plate 2. The impeller 5 is fixedly connected to the other end of the rotating shaft 8. Several first blades 511 and several second blades 512 are arranged on the side of the impeller 5 facing the upper wind cover 14. The first blades 511 and the second blades 512 are perpendicular to the impeller 5, and the first blades 511, the second blades 512 and the impeller 5 are integrally formed. The first blades 511 and the second blades 512 are equidistantly arranged and are arranged alternately. The first blades 511 and the second blades 512 are both clockwise. One end of the first blade 511 is located near the central axis of the side of the impeller 5 facing the upper wind cover 14, and the other end of the first blade 511 is flush with the circumference of the impeller 5. The length of the second blade 512 is half the length of the first blade 511. One end of the second blade 512 is flush with the circumference of the impeller 5, and the other end of the second blade 512 is located in the middle position between two adjacent first blades 511. A disc rotor 6 is provided on the side of the impeller 5 facing the isolation plate 2. The disc rotor 6 is an integral circular permanent magnet. The disc rotor 6 is embedded in the side of the impeller 5 facing the isolation plate 2. The disc stator 4, the isolation plate 2, the disc rotor 6, the impeller 5, the bearing 7 and the rotating shaft 8 are all coaxially arranged.

[0041] like Figure 2 and Figure 3 An isolation element 52 is also provided on the side of the impeller 5 facing the isolation plate 2. The isolation element 52 includes an isolation sleeve 521. The isolation sleeve 521 is fixed on the side of the impeller 5 facing the isolation plate 2. The isolation sleeve 521 is coaxially arranged with the impeller 5. The isolation sleeve 521 extends out of the bottom surface of the impeller 5 and supports the isolation plate 2. The isolation sleeve 521 passes through the disc rotor 6 and covers the outside of the cylindrical protrusion 21. The isolation sleeve 521 is provided with a plurality of third blades 522 along its outer peripheral surface. The plurality of third blades 522 are arranged at equal intervals. The isolation sleeve 521 and the third blades 522 are integrally formed. The third blades 522 are rotated counterclockwise. The rotation direction of the third blades 522 is opposite to that of the first blade 511 and the second blade 512. An annular protrusion 531 is provided on the side of the impeller 5 facing the isolation plate 2. The annular protrusion 531 is located inside the isolation sleeve 521. The diameter of the annular protrusion 531 is smaller than the diameter of the isolation sleeve 521. The annular protrusion 531 is coaxially arranged with the impeller 5. Several connecting blocks 532 are fixedly arranged along the outer circumference of the annular protrusion 531. The connecting blocks 532 are equidistant from each other. The annular protrusion 531 and the connecting blocks 532 are integrally formed. The connecting blocks 532 extend from the annular protrusion 531 toward the isolation sleeve 521. A positioning block 533 is fixedly arranged at the end of the connecting block 532 near the isolation sleeve 521. The positioning block 533 corresponds to the connecting block 532 one by one. The positioning block 533 is arranged facing the isolation plate 2. The connecting block 532 is located inside the isolation sleeve 521. The fixing block is located between the isolation sleeve 521 and the cylindrical protrusion 21. The positioning block 533 is fitted against the outer circumferential wall of the cylindrical protrusion 21.

[0042] The implementation principle of this application embodiment is as follows: It simultaneously achieves dual physical isolation of the disc stator 4 and the bearing 7. The isolation plate 2 blocks the possibility of flammable and explosive gases contacting the stator, avoiding the risk of explosion caused by the encounter of sparks and gases. The isolation component 52 prevents corrosive gases from directly contacting the bearing 7 and causing damage to the components, and prevents the grease on the bearing 7 from contaminating the transported gas, thus achieving bidirectional isolation protection between the gas and the bearing 7, and enhancing the corrosion resistance and protection of the fan. The disc rotor 6 is embedded in the impeller 5 and can directly drive the impeller 5 to rotate, improving the efficiency of force transmission, reducing energy loss, and making the structure of the fan more compact and flat, thereby reducing the axial space of the fan. At the same time, the disc rotor 6 is an integral ring-shaped permanent magnet structure, which can stably withstand high-speed centrifugal force by its own strength, avoiding the generation of unilateral axial magnetic pull, and better adapting to high-speed operation.

[0043] In other embodiments, the isolation plate 2 may be other highly thermally conductive materials such as an aluminum nitride ceramic substrate; like Figure 4 The isolation plate 2 can also be integrally formed with the lower hood 15. A rear end cover 16 is provided on the side of the lower hood 15 away from the isolation plate 2. The disc stator 4 is located between the lower hood 15 and the rear end cover 16. The disc stator 4 can also have an iron core structure. The first blade 511 and the second blade 512 can also rotate counterclockwise. The length of the second blade 512 can also be one-third of the length of the first blade 511 or other lengths. The disc rotor 6 can be a segmented winding rotor. The third blade 522 can rotate clockwise. The rotation direction of the third blade 522 can be the same as the rotation direction of the first blade 511 and the second blade 512.

[0044] Example 2 Reference Figure 5 and Figure 6The difference between this embodiment and embodiment 1 is that the isolation member 52 includes an annular fixing plate 523, which is fixedly disposed on the side of the impeller 5 facing the isolation plate 2. The annular fixing plate 523 is located outside the third blade 522 and is coaxially disposed with the isolation sleeve 521. Four arc-shaped cover plates 524 are hinged to the outer edge of the annular fixing plate 523. The four arc-shaped cover plates 524 are the same size. Both ends of the arc-shaped cover plates 524 along the contour direction are hinged with fan-shaped plates 525. Two adjacent fan-shaped plates 525 are hinged together. The fan-shaped plates 525 are the same size. The annular fixing plate 523, the arc-shaped cover plates 524 and the fan-shaped plates 525 are all located between the third blade 522 and the disc rotor 6.

[0045] In other embodiments, the annular fixing plate 523 may be fixedly disposed on the inner edge of the disc rotor 6.

[0046] The implementation principle of Example 2 is as follows: When the fan stops running, the arc-shaped cover plate 524 and the fan-shaped plate 525 are subjected to gravity. The fan-shaped plate 525 folds inward and is perpendicular to the partition plate 2 and in contact with the partition plate. At this time, the arc-shaped cover plate 524, the partition plate 2 and the impeller 5 form a physical isolation space to protect the internal components such as the bearing 7. When the fan runs, the arc-shaped cover plate 524 and the fan-shaped plate 525 are subjected to centrifugal force. The fan-shaped plate 525 unfolds and is parallel to the partition plate 2. The two are in contact with the impeller 5. At this time, the flow field generated by the rotation of the third blade 522 provides a path for the gas to move to the air supply channel 13, ensuring that the grease in the bearing 7 will not contaminate the purity of the gas discharged by the fan, and that the corrosive gas will not affect the internal equipment such as the bearing 7.

[0047] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An explosion-proof and corrosion-resistant fan, characterized in that: The device includes a mounting housing (1), an isolation plate (2) installed inside the mounting housing (1), a disc stator (4) installed inside the mounting housing (1), an impeller (5) rotatably mounted on the isolation plate (2), the disc stator (4) and the impeller (5) located on both sides of the isolation plate (2), an isolation element (52) and a disc rotor (6) are provided on the side of the impeller (5) facing the disc stator (4), the isolation plate (2) is used to form a physical isolation between the disc stator (4) and the impeller (5), the disc rotor (6) and the drawn-in gas, the isolation element (52) is used to prevent the drawn-in gas from entering the rotating connection of the impeller (5), an air inlet (11) is provided on the top surface of the mounting housing (1), an air outlet (12) is provided on the side of the mounting housing (1), and an air supply channel (13) is provided along its circumference inside the mounting housing (1).

2. The explosion-proof and corrosion-resistant fan according to claim 1, characterized in that: A cylindrical protrusion (21) is fixedly provided on the isolation plate (2), the cylindrical protrusion (21) is positioned facing the impeller (5), a bearing (7) is fixedly provided inside the cylindrical protrusion (21), a rotating shaft (8) is rotatably provided on the bearing (7), and the rotating shaft (8) is fixedly connected to the impeller (5).

3. The explosion-proof and corrosion-resistant fan according to claim 2, characterized in that: The impeller (5) has a plurality of first blades (511) and a plurality of second blades (512) fixedly arranged on the side facing the air inlet (11). The first blades (511) and the second blades (512) are arranged alternately. One end of the first blade (511) is located near the central axis of the side of the impeller (5) facing the air inlet (11). The other end of the first blade (511) is flush with the circumferential surface of the impeller (5). One end of the second blade (512) is flush with the circumferential surface of the impeller (5). The other end of the second blade (512) is located at one-third to one-half of the length of the first blade (511).

4. The explosion-proof and corrosion-resistant fan according to claim 3, characterized in that: The isolation element (52) includes an isolation sleeve (521), which is fixed to the side of the impeller (5) facing the isolation plate (2), the isolation sleeve (521) covers the cylindrical protrusion (21), and the isolation sleeve (521) is supported on the isolation plate (2).

5. The explosion-proof and corrosion-resistant fan according to claim 4, characterized in that: The isolation sleeve (521) is provided with a plurality of third blades (522) along its circumference. The third blades (522) are located on the side of the isolation sleeve (521) away from the cylindrical protrusion (21). The first blade (511) and the second blade (512) are arranged in the same direction of rotation, and the third blade (522) is arranged in the opposite direction of rotation to the first blade (511).

6. The explosion-proof and corrosion-resistant fan according to claim 4, characterized in that: The impeller (5) is also provided with an annular protrusion (531) on the side facing the isolation plate (2). The annular protrusion (531) is coaxially arranged with the impeller (5). A plurality of connecting blocks (532) are fixedly connected to the annular protrusion (531) along its outer circumference. The connecting blocks (532) are fixedly connected to positioning blocks (533). The positioning blocks (533) are located between the isolation sleeve (521) and the cylindrical protrusion (21). The positioning blocks (533) are fitted to the outer circumference of the cylindrical protrusion (21).

7. The explosion-proof and corrosion-resistant fan according to claim 4, characterized in that: The disc rotor (6) is embedded in the side of the impeller (5) away from the air inlet (11). The disc rotor (6) is a ring-shaped permanent magnet. The isolation sleeve (521) passes through the disc rotor (6). The disc stator (4), the disc rotor (6) and the cylindrical protrusion (21) are all coaxially arranged with the rotating shaft (8).

8. The explosion-proof and corrosion-resistant fan according to claim 1, characterized in that: The mounting housing (1) includes an upper shroud (14) and a lower shroud (15). The air inlet (11) is opened on the upper shroud (14). The upper shroud (14) and the lower shroud (15) together form a volute-like structure. The air outlet (12) is formed at the port of the upper shroud (14) and the lower shroud (15).

9. The explosion-proof and corrosion-resistant fan according to claim 8, characterized in that: One side of the disc stator (4) is attached to the inner wall of the lower hood (15), the other side of the disc stator (4) is attached to the isolation plate (2), and the side of the isolation plate (2) is attached to the inner wall of the lower hood (15).

10. The explosion-proof and corrosion-resistant fan according to claim 5, characterized in that: An annular fixing plate (523) is fixedly installed on the side of the impeller (5) facing the isolation plate (2). Several arc-shaped cover plates (524) are hinged on the annular fixing plate (523). Both ends of the arc-shaped cover plates (524) are hinged with fan-shaped plates (525). Adjacent fan-shaped plates (525) are hinged together. The arc-shaped cover plates (524) and the fan-shaped plates (525) are located between the third blade (522) and the disc rotor (6). When the impeller (5) is stationary, the fan-shaped plates (524) are... 25) Folding towards the interior of the third blade (522), the arc-shaped cover plate (524) is perpendicular to the isolation plate (2), and several arc-shaped cover plates (524) together surround the third blade (522). When the impeller (5) rotates, the fan-shaped plate (525) unfolds, and the fan-shaped plate (525) and the arc-shaped cover plate (524) form a ring structure. The fan-shaped plate (525) and the arc-shaped cover plate (524) are attached to the side of the impeller (5) facing the isolation plate (2).

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