Cantilever type multistage centrifugal blower

Abstract

The invention discloses a cantilever type multistage centrifugal blower, and relates to the technical field of fan gas delivery, the cantilever type multistage centrifugal blower comprises an integral base and a water cooling assembly, a motor is fixed at the rear end of the integral base, the output end of the motor is fixedly connected with a coupler, the motor is in transmission connection with a main shaft through the coupler, and the front end of the main shaft is connected with a shaft end cooling device; the water cooling assembly is arranged in the middle of the shaft end cooling device. In the using process of the shaft end cooling device, through the cooling unit of a triple structure, the hot air amount of a high-temperature gas medium leaking out of a machine shell shaft hole is gradually decreased, and heat transmitted to a bearing by the high-temperature medium is effectively controlled; and the reciprocating power of the piston rod in the third structural unit is provided by the heat dissipation swash plate fixed with the main shaft, so that the circulating spraying of the cooling water is linked with the rotation of the main shaft, the circulating spraying of the cooling water is realized without the help of other external devices, and the cooling effect is improved on the basis of the prior art through reasonable structural design.

Description

Technical Field

[0001] The invention relates to the technical field of fan gas delivery, in particular to a cantilever multi-stage centrifugal blower. Background Art

[0002] With the continuous advancement of the country's energy-saving and consumption-reduction policies and the rapid development of the national economy, all walks of life have an increasing demand for fans, and the requirements are becoming more differentiated. Ordinary multi-stage blowers have complex structures and are suitable for large flow and high pressure conditions, while small flow and high pressure conditions often require the use of less efficient Roots blowers, which have a narrow adjustable range and are inconvenient to inspect and maintain.

[0003] When the multi-stage centrifugal blower is used to transport high-temperature and corrosive flue gas, if the material of the fan, the structure of the casing, the impeller, the cooling device at the shaft end, etc. are not properly selected and designed, the fan will not be able to operate stably for a long time, causing economic losses and even safety accidents, making it difficult to ensure the long-term stable and safe operation of the fan.

[0004] Therefore, in view of this, the existing structural deficiencies are studied and improved, and a cantilever multi-stage centrifugal blower is proposed. Summary of the invention

[0005] The object of the present invention is to provide a cantilever multi-stage centrifugal blower to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a cantilever multi-stage centrifugal blower, comprising an integral base and a water-cooling assembly, wherein a motor is fixed at the rear end of the integral base, and a coupling is fixedly connected to the output end of the motor, and the motor is connected to the main shaft through the coupling, and a shaft end cooling device is connected to the front end of the main shaft, and the water-cooling assembly is arranged in the middle of the shaft end cooling device, and the water-cooling assembly comprises an outer sleeve, a piston cylinder, a piston rod, a connecting arm, a return pipe, a gravity ball, a water receiving box, an opening recess and a drain valve, a piston cylinder is fixed to the upper cavity part of the outer sleeve, and a piston rod is slidably installed inside the piston cylinder, and two connecting arms are fixed to the end of the piston rod, a return pipe is connected to the side of the piston cylinder, and a gravity ball with a hollow structure is connected to the end of the return pipe, a water receiving box is fixed to the lower cavity part of the outer sleeve, and a crescent-shaped middle part of the water receiving box is provided with a downwardly concave opening recess, a water storage cavity inside the water receiving box is connected to the piston cylinder through the return pipe, and a drain valve is connected to the bottom of the water receiving box.

[0007] Furthermore, a heat dissipation swash plate fixed to the main shaft is provided at the rear end of the shaft end cooling device, and the front and rear disk surfaces of the heat dissipation swash plate are in contact with the roller at the end of the connecting arm, and the main shaft drives the piston rod to reciprocate back and forth inside the piston cylinder through the cooperation of the heat dissipation swash plate and the connecting arm.

[0008] Furthermore, a labyrinth seal is provided at the front end of the shaft end cooling device, and the rear end flange of the labyrinth seal is bolted to the outer sleeve, and five high-temperature resistant copper sealing teeth are inlaid inside the middle hole of the labyrinth seal.

[0009] Furthermore, several atomizing water spraying components are arranged at the bottom end of the arc surface of the piston cylinder, and the atomizing water spraying components include a screw threaded tube, which is threadedly fixed to several spraying holes opened at the bottom end of the piston cylinder, and the screw threaded tube is a columnar structure with openings at both ends.

[0010] Furthermore, the atomizing water spray assembly also includes a cross and a rubber sheet. The top opening of the screw tube is fixed with a cross, and the middle of the cross is clamped with a rubber sheet that can only be folded inwards.

[0011] Furthermore, the atomizing water spray assembly also includes wing plates and water dividing teeth. Wing plates are fixed on both sides of the bottom opening of the spiral tube, and water dividing teeth are rotatably installed on the opposite surfaces of the ends of the wing plates on both sides, and the part of the top of the water dividing teeth facing the bottom opening of the spiral tube is a conical structure.

[0012] Furthermore, the main shaft is rotatably mounted inside the bearing box, and the bearing box is fixed to the middle of the integral base, a second-stage casing is fixed to the front end of the integral base, and the second-stage casing is bolted to the front end flange of the labyrinth seal.

[0013] Furthermore, a second-stage impeller is rotatably mounted inside the second-stage casing, and the second-stage impeller is mounted on a main shaft inside the second-stage casing.

[0014] Furthermore, a central shaft sleeve is mounted on the main shaft, and a first-stage impeller is connected to the front end of the main shaft, and the first-stage impeller is fixed to the main shaft bolts through a shaft end disc.

[0015] Furthermore, the first-stage impeller is rotatably mounted inside the first-stage casing, and the first-stage casing is fixed to the second-stage casing by bolts, and the first-stage casing is fixed to the air inlet cylinder by bolts.

[0016] The present invention provides a cantilever multi-stage centrifugal blower having the following beneficial effects:

[0017] 1. During the use of the present invention, the shaft end cooling device of the present application is composed of three parts. The first structural unit located at the front end is a labyrinth seal. When in use, the high-temperature gas medium leaks out from the shaft hole of the casing. After entering the labyrinth, the amount of hot gas decreases layer by layer. The second structural unit located at the rear end is a heat dissipation swash plate. On the one hand, the heat dissipation swash plate is directly fixed on the main shaft and dissipates heat to the surrounding air through high-speed rotation, reducing the amount of contact with the bearing box to protect its internal bearings from high temperature. On the other hand, the main shaft drives the piston rod to reciprocate back and forth inside the piston cylinder through the cooperation of the heat dissipation swash plate and the connecting arm. The third structural unit located at the middle end is a water-cooling component sleeved on the outside of the main shaft. During the suction stroke of the piston cylinder in the cavity of the outer sleeve, the piston cylinder absorbs water in the water storage cavity inside the water receiving box through the return pipe. During the discharge stroke, the water in the piston cylinder is discharged from the piston cylinder. Under the push of the rod, water is sprayed out from the atomizing spray assembly connected to several spray holes at the bottom of the arc surface, and is sprayed on the shaft sleeve of the main shaft to take away the heat. The warm water flows along the shaft sleeve into the lower cavity and then merges into the opening notch in the middle of the crescent-shaped water receiving box, so that the water can be continuously sprayed on the shaft sleeve of the main shaft to play a cooling role. The shaft end cooling device of the present application uses a triple-structure cooling unit to gradually reduce the amount of hot gas leaked from the shaft hole of the casing by the high-temperature gas medium, effectively controlling the heat transmitted to the bearing by the high-temperature medium. In addition, the reciprocating power of the piston rod in the third structural unit is provided by the heat dissipation inclined plate fixed to the main shaft, so that the circulating spray of cooling water is linked with the rotation of the main shaft, and the circulating spray of cooling water is realized without the help of other external devices. The cooling effect is further improved on the existing technology through reasonable structural design.

[0018] 2. During the use of the present invention, the motor of the present application drives the main shaft to rotate through the coupling, driving the first-stage impeller and the second-stage impeller cantilevered on the main shaft to work in series, thereby realizing a cantilevered multi-stage centrifugal blower. Therefore, the cantilevered multi-stage centrifugal blower has the characteristics of short production cycle, low manufacturing cost, high safety and reliability, compact structure, high efficiency, wide adjustable range, convenient inspection and maintenance, etc. It is particularly suitable for occasions such as conveying small flow, high pressure, and wide operating condition adjustment range. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention;

[0020] Figure 2 It is a front view structural schematic diagram of the shaft end cooling device of the present invention;

[0021] Figure 3 It is a schematic diagram of the side structure of the shaft end cooling device of the present invention;

[0022] Figure 4 It is a schematic diagram of the three-dimensional structure of the shaft end cooling device of the present invention;

[0023] Figure 5 This is a schematic diagram of the cross-sectional structure of the labyrinth seal of the present invention;

[0024] Figure 6 It is a schematic diagram of the cross-sectional structure of the water cooling assembly of the present invention;

[0025] Figure 7 It is a schematic diagram of the cross-sectional structure of the atomizing water spray assembly of the present invention.

[0026] In the figure: 1. integral base; 2. motor; 3. coupling; 4. main shaft; 5. bearing box; 6. second-stage casing; 7. second-stage impeller; 8. middle shaft sleeve; 9. first-stage impeller; 10. shaft end disc; 11. first-stage casing; 12. air inlet pipe; 13. shaft end cooling device; 14. heat dissipation inclined plate; 15. labyrinth seal; 16. flange; 17. sealing tooth; 18. water cooling assembly; 1801. outer sleeve; 1802. piston cylinder; 1803. piston rod; 1804. connecting arm; 1805. return pipe; 1806. gravity ball; 1807. water receiving box; 1808. opening notch; 1809. drain valve; 19. atomizing water spray assembly; 1901. screw pipe; 1902. cross; 1903. rubber sheet; 1904. wing plate; 1905. water dividing tooth. DETAILED DESCRIPTION

[0027] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following embodiments are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0028] See also Figures 1 to 7The present invention provides a technical solution: a cantilever multi-stage centrifugal blower, comprising an integral base 1 and a water cooling assembly 18, wherein a motor 2 is fixed to the rear end of the integral base 1, and a coupling 3 is fixedly connected to the output end of the motor 2, and the motor 2 is connected to the main shaft 4 through the coupling 3, and the front end of the main shaft 4 is connected to the shaft end cooling device 13, and the water cooling assembly 18 is arranged in the middle of the shaft end cooling device 13, and the water cooling assembly 18 comprises an outer sleeve 1801, a piston cylinder 1802, a piston rod 1803, a connecting arm 1804, a return pipe 1805, a weight The outer sleeve 1801 has a gravity ball 1806, a water receiving box 1807, an opening notch 1808 and a drain valve 1809. The piston cylinder 1802 is fixed to the upper cavity of the outer sleeve 1801, and a piston rod 1803 is slidably installed inside the piston cylinder 1802, and two connecting arms 1804 are fixed to the end of the piston rod 1803. The side of the piston cylinder 1802 is connected to a return pipe 1805, and the end of the return pipe 1805 is connected to a gravity ball 1806 with a hollow structure. The water receiving box 1807 is fixed to the lower cavity of the outer sleeve 1801, and the water receiving box 1807 is fixed to the lower cavity of the outer sleeve 1801. A downwardly sunken opening notch 1808 is provided in the middle of the tooth shape, the water storage chamber inside the water receiving box 1807 is connected to the piston cylinder 1802 through the return pipe 1805, and the bottom of the water receiving box 1807 is connected to a drain valve 1809, and several atomizing water spraying components 19 are arranged at the bottom of the arc surface of the piston cylinder 1802, and the atomizing water spraying components 19 include a screw thread tube 1901, and the screw thread tube 1901 is threadedly fixed to the several spraying holes opened at the bottom of the piston cylinder 1802, and the screw thread tube 1901 is a columnar structure with openings at both ends, and the atomizing water spraying components 19 It also includes a cross 1902 and a rubber sheet 1903. The cross 1902 is fixed to the top opening of the screw tube 1901, and the middle of the cross 1902 is clamped with a rubber sheet 1903 that can only be folded inwards. The atomizing water spraying assembly 19 also includes a wing plate 1904 and a water dividing tooth 1905. The wing plates 1904 are fixed on both sides of the bottom opening of the screw tube 1901, and the water dividing teeth 1905 are rotatably installed on the opposite surfaces of the ends of the wing plates 1904 on both sides, and the top of the water dividing tooth 1905 facing the bottom opening of the screw tube 1901 is a conical structure.

[0029] The specific operation is as follows: the third structural unit located at the middle end is a water-cooling component 18 sleeved on the outside of the main shaft 4; during the suction stroke of the piston cylinder 1802 of the cavity of the outer sleeve 1801, the piston cylinder 1802 absorbs water in the water storage cavity inside the water receiving box 1807 through the return pipe 1805; during the discharge stroke, the water in the piston cylinder 1802 is pushed by the piston rod 1803 and sprayed out by the atomizing water spray component 19 connected to the spray holes at the bottom end of the arc surface; the rubber sheet 1903 connected to the top opening of the screw tube 1901 through the cross 1902 can only be folded inward to play a one-way sealing role; the water discharged at a high speed from the bottom opening of the screw tube 1901 is fully atomized when it contacts the water dividing teeth 1905, and is sprayed on the shaft sleeve of the main shaft 4 to take away the heat, and the warm water flows along the shaft After the sleeve flows into the lower cavity, it flows into the opening notch 1808 in the middle of the crescent-shaped water receiving box 1807, and the water is recycled for a second time, so that the water can be continuously sprayed on the sleeve of the main shaft 4 to cool it down. The shaft end cooling device 13 of the present application uses a triple-structure cooling unit to gradually reduce the amount of hot gas leaked from the shaft hole of the casing by the high-temperature gas medium, effectively controlling the heat transmitted to the bearing by the high-temperature medium. In addition, the reciprocating power of the piston rod 1803 in the third structural unit is provided by the heat dissipation inclined plate 14 fixed to the main shaft 4, which links the circulating spray of cooling water with the rotation of the main shaft 4, and does not need to rely on other external devices to realize the circulating spray of cooling water. The cooling effect is further improved on the existing technology through reasonable structural design.

[0030] See also Figures 4 to 6 , a heat dissipation swash plate 14 fixed to the main shaft 4 is provided at the rear end of the shaft end cooling device 13, and the front and rear disk surfaces of the heat dissipation swash plate 14 are in contact with the roller at the end of the connecting arm 1804, and the main shaft 4 drives the piston rod 1803 to reciprocate inside the piston cylinder 1802 through the cooperation of the heat dissipation swash plate 14 and the connecting arm 1804, a labyrinth seal 15 is provided at the front end of the shaft end cooling device 13, and the rear end flange 16 of the labyrinth seal 15 is bolted to the outer sleeve 1801, and five high-temperature resistant copper sealing teeth 17 are inlaid inside the middle hole of the labyrinth seal 15;

[0031] The specific operation is as follows: the first structural unit located at the front end is a labyrinth seal 15, the front end flange 16 of the labyrinth seal 15 is fixed to the rear side plate of the second-stage casing 6 by bolts, and the rear end flange 16 of the labyrinth seal 15 is fixed to the outer sleeve 1801 by bolts. Five high-temperature resistant copper sealing teeth 17 are inlaid inside the middle hole of the labyrinth seal 15. When in use, the high-temperature gas medium leaks out from the shaft hole of the casing, and the amount of hot gas decreases layer by layer after entering the labyrinth. The second structural unit located at the rear end is a heat dissipation swash plate 14. On the one hand, the heat dissipation swash plate 14 is directly fixed on the main shaft 4 and dissipates heat to the surrounding air through high-speed rotation, thereby reducing the contact amount with the bearing box 5 to protect its internal bearings from being affected by high temperature. On the other hand, the main shaft 4 drives the piston rod 1803 to reciprocate back and forth inside the piston cylinder 1802 through the cooperation of the heat dissipation swash plate 14 and the connecting arm 1804;

[0032] See also Figure 1 , the main shaft 4 is rotatably mounted inside the bearing box 5, and the bearing box 5 is fixed to the middle of the integral base 1, a second-stage casing 6 is fixed to the front end of the integral base 1, and the second-stage casing 6 is bolted to the front end flange 16 of the labyrinth seal 15, a second-stage impeller 7 is rotatably mounted inside the second-stage casing 6, and the second-stage impeller 7 is mounted on the main shaft 4 in the second-stage casing 6, a middle shaft sleeve 8 is mounted on the main shaft 4, and a first-stage impeller 9 is connected to the front end of the main shaft 4, and the first-stage impeller 9 is bolted to the main shaft 4 through a shaft end disc 10, the first-stage impeller 9 is rotatably mounted inside the first-stage casing 11, and the first-stage casing 11 is bolted to the second-stage casing 6, and the first-stage casing 11 is bolted to the air inlet cylinder 12 through bolts;

[0033] The specific operation is as follows: the motor 2 of the present application drives the main shaft 4 to rotate through the coupling 3, driving the first-stage impeller 9 and the second-stage impeller 7 cantilevered mounted on the main shaft 4 to work in series, thereby realizing a cantilevered multi-stage centrifugal blower. Therefore, the cantilevered multi-stage centrifugal blower has the characteristics of short production cycle, low manufacturing cost, high safety and reliability, compact structure, high efficiency, wide adjustable range, easy inspection and maintenance, etc., and is particularly suitable for occasions such as conveying small flow, high pressure, and wide operating condition adjustment range.

[0034] In summary, when the cantilever multi-stage centrifugal blower is used, the motor 2 of the present application drives the main shaft 4 to rotate through the coupling 3, driving the first-stage impeller 9 and the second-stage impeller 7 cantilevered mounted on the main shaft 4 to work in series, thereby realizing a cantilever multi-stage centrifugal blower. Therefore, the cantilever multi-stage centrifugal blower has the characteristics of short production cycle, low manufacturing cost, high safety and reliability, compact structure, high efficiency, wide adjustable range, convenient inspection and maintenance, etc. It is particularly suitable for occasions such as conveying small flow, high pressure, and wide operating condition adjustment range. The shaft end cooling device 13 of the present application is composed of three parts. The first structural unit located at the front end is a labyrinth seal 15. The front end flange 16 of the labyrinth seal 15 is fixed to the rear side plate of the second-stage casing 6 by bolts. The rear end flange 16 of the labyrinth seal 15 is fixed to the outer sleeve 1801 by bolts. Five high-temperature resistant copper sealing teeth 17 are inlaid inside the middle hole of the labyrinth seal 15. When in use, the high-temperature gas medium leaks out from the shaft hole of the casing, and the amount of hot gas decreases layer by layer after entering the labyrinth. The second structural unit at the rear end is the heat dissipation swash plate 14. On the one hand, the heat dissipation swash plate 14 is directly fixed on the main shaft 4 and dissipates heat to the surrounding air through high-speed rotation, reducing the contact with the bearing box 5 to protect its internal bearings from high temperature. On the other hand, the main shaft 4 drives the piston rod 1803 to reciprocate back and forth inside the piston cylinder 1802 through the cooperation of the heat dissipation swash plate 14 and the connecting arm 1804. The third structural unit at the middle end It is a water-cooling component 18 sleeved on the outside of the main shaft 4. During the suction stroke of the piston cylinder 1802 in the upper cavity of the outer sleeve 1801, the piston cylinder 1802 absorbs water in the water storage cavity inside the water receiving box 1807 through the return pipe 1805. During the discharge stroke, the water in the piston cylinder 1802 is pushed by the piston rod 1803 and sprayed out from the atomizing water spray component 19 connected to several spray holes at the bottom end of the arc surface. The rubber sheet 1903 connected to the top opening of the screw tube 1901 through the cross 1902 can only be folded inward to play a one-way sealing role, and the water discharged at a high speed from the bottom opening of the screw tube 1901 is fully atomized when it contacts the water dividing teeth 1905, and is sprayed on the shaft sleeve of the main shaft 4 to take away the heat. The warm water flows along the shaft sleeve into the lower cavity and then merges into In the opening recess 1808 in the middle of the crescent-shaped water collecting box 1807, water is recycled for secondary use so that it can be continuously sprayed on the sleeve of the main shaft 4 to cool the shaft. The shaft end cooling device 13 of the present application uses a triple-structure cooling unit to gradually reduce the amount of hot gas leaked from the shaft hole of the casing by the high-temperature gas medium, thereby effectively controlling the heat transmitted to the bearing by the high-temperature medium. Moreover, the reciprocating power of the piston rod 1803 in the third structural unit is provided by the heat dissipation inclined plate 14 fixed to the main shaft 4, which links the circulating spraying of cooling water with the rotation of the main shaft 4. There is no need to use other external devices to achieve the circulating spraying of cooling water, and the cooling effect is further improved on the existing technology through reasonable structural design.

[0035] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various implementations with various modifications suitable for specific uses.

Claims

1. A cantilever multi-stage centrifugal blower, characterized in that: The invention comprises an integral base (1) and a water cooling assembly (18), wherein a motor (2) is fixed at the rear end of the integral base (1), and a coupling (3) is fixedly connected to the output end of the motor (2), and the motor (2) is drivingly connected to a main shaft (4) via the coupling (3), and the front end of the main shaft (4) is connected to a shaft end cooling device (13), and the water cooling assembly (18) is arranged in the middle of the shaft end cooling device (13), and the water cooling assembly (18) comprises an outer sleeve (1801), a piston cylinder (1802), a piston rod (1803), a connecting arm (1804), a water return pipe (1805), a gravity ball (1806), a water receiving box (1807), an opening recess (1808) and a drain valve (1809), and the upper cavity portion of the outer sleeve (1801) is fixed A piston cylinder (1802) is fixed, and a piston rod (1803) is slidably installed inside the piston cylinder (1802), and two connecting arms (1804) are fixed to the ends of the piston rod (1803). The side of the piston cylinder (1802) is connected to a return pipe (1805), and the end of the return pipe (1805) is connected to a gravity ball (1806) with a hollow structure. A water receiving box (1807) is fixed to the lower cavity of the outer sleeve (1801), and a downwardly concave opening (1808) is opened in the middle of the crescent-shaped water receiving box (1807). The water storage cavity inside the water receiving box (1807) is connected to the piston cylinder (1802) through the return pipe (1805), and the bottom of the water receiving box (1807) is connected to a drain valve (1809).

2. A cantilever multi-stage centrifugal blower according to claim 1, characterized in that: The rear end of the shaft end cooling device (13) is provided with a heat dissipation swash plate (14) fixed to the main shaft (4), and the front and rear disk surfaces of the heat dissipation swash plate (14) are in contact with the roller at the end of the connecting arm (1804), and the main shaft (4) drives the piston rod (1803) to reciprocate back and forth inside the piston cylinder (1802) through the cooperation between the heat dissipation swash plate (14) and the connecting arm (1804).

3. The cantilever multi-stage centrifugal blower according to claim 1, characterized in that: The front end of the shaft end cooling device (13) is provided with a labyrinth seal (15), and the rear end flange (16) of the labyrinth seal (15) is bolted to the outer sleeve (1801), and five high-temperature resistant copper sealing teeth (17) are embedded in the middle hole of the labyrinth seal (15).

4. The cantilever multi-stage centrifugal blower according to claim 1, characterized in that: Several atomizing water spraying assemblies (19) are arranged at the arcuate bottom end of the piston cylinder (1802), and the atomizing water spraying assemblies (19) include a screw thread tube (1901), and the screw thread tube (1901) is threadedly fixed to several spraying holes opened at the bottom end of the piston cylinder (1802), and the screw thread tube (1901) is a columnar structure with openings at both ends.

5. The cantilever multi-stage centrifugal blower according to claim 4, characterized in that: The atomizing water spray assembly (19) further comprises a cross (1902) and a rubber sheet (1903); the cross (1902) is fixed to the top opening of the screw tube (1901), and the middle of the cross (1902) is clamped with a rubber sheet (1903) that can only be folded inwards.

6. The cantilever multi-stage centrifugal blower according to claim 5, characterized in that: The atomizing water spray assembly (19) further comprises a wing plate (1904) and a water dividing tooth (1905), the wing plates (1904) being fixed on both sides of the bottom opening of the spiral tube (1901), and the water dividing teeth (1905) being rotatably mounted on opposite surfaces of the ends of the wing plates (1904) on both sides, and the top end of the water dividing tooth (1905) facing the bottom opening of the spiral tube (1901) is in a conical structure.

7. The cantilever multi-stage centrifugal blower according to claim 1, characterized in that: The main shaft (4) is rotatably mounted inside a bearing box (5), and the bearing box (5) is fixed to the middle of the integral base (1). A second-stage housing (6) is fixed to the front end of the integral base (1), and the second-stage housing (6) is bolted to the front end flange (16) of the labyrinth seal (15).

8. The cantilever multi-stage centrifugal blower according to claim 7, characterized in that: A second-stage impeller (7) is rotatably mounted inside the second-stage casing (6), and the second-stage impeller (7) is mounted on the main shaft (4) inside the second-stage casing (6).

9. The cantilever multi-stage centrifugal blower according to claim 8, characterized in that: The main shaft (4) is sleeved with a middle shaft sleeve (8), and the front end of the main shaft (4) is connected to a first-stage impeller (9), and the first-stage impeller (9) is bolted to the main shaft (4) via a shaft end disc (10).

10. The cantilever multi-stage centrifugal blower according to claim 9, characterized in that: The first-stage impeller (9) is rotatably mounted inside the first-stage casing (11), and the first-stage casing (11) is fixed to the second-stage casing (6) by bolts, and the first-stage casing (11) is fixed to the air inlet cylinder (12) by bolts.

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