Double-suction three-dimensional impeller assembly for large high-temperature centrifugal fans

Abstract

This invention discloses a double-suction three-dimensional flow impeller assembly for large high-temperature centrifugal fans. The double-suction three-dimensional flow impeller assembly includes: a main shaft, a connecting disc, and two sets of three-dimensional flow impeller devices. Each three-dimensional flow impeller device consists of an arc-lifting sleeve, multiple blades, a blade cover plate, and a locking nut. The two sets of three-dimensional flow impeller devices are structurally symmetrical. The arc-lifting sleeve, blades, and blade cover plate are all single-piece components. The arc-lifting sleeve is formed by splicing an inner section and an outer section, the blade cover plate is formed by splicing an inner plate and an outer plate, and each blade is formed by splicing an inner blade and an outer blade. The beneficial technical effect of this invention is that it proposes a double-suction three-dimensional flow impeller assembly for large high-temperature centrifugal fans. This solution can maintain the integrity of the three-dimensional flow impeller blades while achieving a stable connection of the main shaft, thus fully leveraging the advantages of the three-dimensional flow impeller.

Description

Technical Field

[0001] This invention relates to a technology for large centrifugal fans, and more particularly to a double-suction three-dimensional flow impeller assembly for large high-temperature centrifugal fans. Background Technology

[0002] The three-dimensional impeller is a relatively advanced impeller configuration that has been widely used in many fields. However, its application in the field of large high-temperature fans has not been very successful. The specific reasons are as follows:

[0003] When using a three-dimensional impeller in a double-suction large fan, in order to save space, the two three-dimensional impellers are generally arranged back to back. The air inlets of the two three-dimensional impellers are located at the two ends of the impeller assembly axis. Considering structural stability, the large fan must adopt F-type transmission. This transmission method requires the main shaft to run through the entire fan. Therefore, the main shaft and the three-dimensional impeller can only be connected at the connecting plate on the back of the three-dimensional impeller.

[0004] Large high-temperature fans used for conveying high-temperature gas media typically operate in the range of 180-700℃. To prevent the connection between the main shaft and the three-dimensional impeller from loosening due to thermal expansion and contraction, an integrated annular protrusion is usually installed on the main shaft, which connects to the connecting plate. Due to the large size and weight of the three-dimensional impeller, and considering the effects of thermal expansion and contraction, the annular protrusion and the connecting plate must be connected by hinged bolts with an interference fit to ensure structural stability. This results in a large radial dimension of the annular protrusion (the outer diameter of the annular protrusion is generally 1.5 times the diameter of the main shaft), and also requires a large operating space for bolt installation.

[0005] Based on existing technology, the air inlet of a three-dimensional flow impeller with complete blades is an annular region. The inner diameter of this annular region is much smaller than the outer diameter of the aforementioned annular protrusion. If a three-dimensional flow impeller with complete blades is used directly, the connection between the annular protrusion and the connecting plate cannot be achieved. To solve this problem, the existing technology omits the blades at the air inlet, thereby increasing the inner diameter of the aforementioned annular region. The resulting space is used to connect the annular protrusion and the connecting plate. The biggest drawback of this solution is that, because the blades at the air inlet are omitted, the air inlet impact increases, and the impeller efficiency is significantly reduced, preventing the advantages of the three-dimensional flow impeller from being fully utilized. At the same time, in order to protect the connection between the annular protrusion and the connecting plate, an additional protective cover is required, which is very troublesome. Summary of the Invention

[0006] To address the problems in the background technology, this invention proposes a double-suction three-dimensional flow impeller assembly for large high-temperature centrifugal fans. Its innovation lies in the following: the double-suction three-dimensional flow impeller assembly includes a main shaft, a connecting disc, and two sets of three-dimensional flow impeller devices; each three-dimensional flow impeller device consists of an arc-lifting sleeve, multiple blades, a blade cover plate, and a locking nut; the two sets of three-dimensional flow impeller devices are structurally symmetrical.

[0007] The spindle has an integral annular protrusion in the middle, and multiple connecting holes are provided on the annular protrusion; the connecting plate has a through hole in the middle, and multiple bolt holes are provided around the through hole; the spindle is sleeved in the through hole, the end face of the connecting plate contacts the end face of the annular protrusion, and bolts are provided in the connecting holes and bolt holes to lock the connecting plate and the annular protrusion.

[0008] The lifting sleeve has a trumpet-shaped structure. The inner diameter of the inner end of the lifting sleeve is larger than the outer diameter of the annular protrusion, and the inner diameter of the outer end of the lifting sleeve is smaller than the outer diameter of the annular protrusion. The lifting sleeve is fitted outside the main shaft, and the two lifting sleeves are located on both sides of the connecting plate. The inner end of the lifting sleeve is fixedly connected to the end face of the connecting plate. The inner edge of the blade is fixedly connected to the surface of the lifting sleeve. The multiple blades of a single three-dimensional flow impeller device are distributed circumferentially. The blade cover plate is fitted outside the main shaft, and the two blade cover plates are located on both sides of the connecting plate. The contour of the inner wall of the blade cover plate is set to follow the shape of the outer edge of the blade. The inner wall of the blade cover plate is fixedly connected to the outer edge of the corresponding blade. The main shaft is provided with two threaded sections, which correspond to the outer ports of the two three-dimensional flow impeller devices. Two locking nuts are threadedly connected to the two threaded sections. The locking nuts are in contact with the outer end face of the corresponding lifting sleeve. The two locking nuts clamp the two three-dimensional flow impeller devices.

[0009] The lifting sleeve, blades, and blade cover are all single-piece components. The lifting sleeve is composed of an inner section and an outer section, with the junction of the inner and outer sections designated as the interface. The interfaces are distributed circumferentially along the lifting sleeve, and the inner diameter of the interface is larger than the outer diameter of the annular protrusion. The blade cover is composed of an inner plate and an outer plate, with the junction of the inner and outer plates designated as the connection port. The connection ports are distributed circumferentially along the blade cover, and the inner diameter of the connection port is larger than the outer diameter of the annular protrusion. A single blade is composed of an inner sheet and an outer sheet, with the junction of the inner and outer sheets designated as the contact surface. The inner end of the contact surface corresponds to the interface, and the outer end of the contact surface corresponds to the connection port. The contact surface is a plane.

[0010] The core idea of ​​the aforementioned solution is to design the complete three-dimensional impeller as an assembled structure. During assembly, the connecting disc inside the three-dimensional impeller is first connected to the annular protrusion on the main shaft. Then, the remaining components of the three-dimensional impeller are installed in place. Finally, the integrity of the three-dimensional impeller blades can be maintained while achieving a stable connection to the main shaft, thereby solving the efficiency loss problem mentioned in the background art. In specific implementation, the following steps can be taken:

[0011] 1) Weld the inner ends of the two inner sections to the corresponding positions on both sides of the connecting plate; weld the inner edges of the multiple outer pieces to the surface of the corresponding outer sections; weld the outer edges of the multiple outer pieces to the inner wall of the corresponding outer plate; the structure composed of the outer sections, outer pieces and outer plates is called component one;

[0012] 2) Weld the inner edges of multiple inner pieces to the surfaces of the corresponding inner sections;

[0013] 3) Weld the inner walls of the two inner plates to the outer edges of the corresponding inner pieces respectively;

[0014] 4) Insert the spindle into the through hole and tighten the connecting plate and the annular protrusion with bolts; the structure consisting of the spindle, connecting plate, inner section, inner plate and inner sheet is called component two;

[0015] 5) Assemble component one and component two together. After assembly, multiple inner pieces are assembled with multiple outer pieces to form multiple complete blades. The inner and outer sections are assembled to form a complete lifting sleeve. The inner and outer plates are assembled to form a complete blade cover plate. Weld and fix the splicing joints. Install two locking nuts into the corresponding positions. The double-suction three-dimensional flow impeller assembly is now complete.

[0016] In practice, to ensure structural stability, a bushing made of lightweight material is installed in the inner hole of the lifting sleeve, and the bushing is fitted onto the main shaft.

[0017] The beneficial technical effects of this invention are: it proposes a double-suction three-dimensional flow impeller assembly for large high-temperature centrifugal fans. This solution can maintain the integrity of the three-dimensional flow impeller blades while achieving a stable connection of the main shaft, thus giving full play to the advantages of the three-dimensional flow impeller. Attached Figure Description

[0018] Figure 1 A schematic diagram of the double-suction three-dimensional flow impeller assembly of the present invention;

[0019] Figure 2 A schematic diagram of the assembly process of this invention;

[0020] Figure 3 Component 1 structural diagram;

[0021] Figure 4 A schematic diagram of the centrifugal fan structure using the double-suction three-dimensional flow impeller assembly of the present invention;

[0022] The names corresponding to the various markings in the figure are as follows: spindle 1, annular protrusion 11, connecting plate 2, lifting sleeve 3, inner section 31, outer section 32, interface 33, blade 4, inner plate 41, outer plate 42, contact surface 43, blade cover plate 5, inner plate 51, outer plate 52, connecting port 53, locking nut 6, air intake 7, drive motor 8, bushing 9. Detailed Implementation

[0023] An innovative double-suction three-dimensional flow impeller assembly for large high-temperature centrifugal fans is as follows: the double-suction three-dimensional flow impeller assembly includes: a main shaft 1, a connecting disc 2, and two sets of three-dimensional flow impeller devices; each three-dimensional flow impeller device consists of an arc-lifting sleeve 3, multiple blades 4, a blade cover plate 5, and a locking nut 6; the two sets of three-dimensional flow impeller devices are structurally symmetrical.

[0024] The spindle 1 has an integral annular protrusion 11 in the middle, and multiple connecting holes are provided on the annular protrusion 11; the connecting plate 2 has a through hole in the middle, and multiple bolt holes are provided around the through hole; the spindle 1 is fitted into the through hole, and the end face of the connecting plate 2 contacts the end face of the annular protrusion 11; bolts are provided in the connecting holes and bolt holes to lock the connecting plate 2 and the annular protrusion 11.

[0025] The lifting sleeve 3 has a trumpet-shaped structure. The inner diameter of the inner end of the lifting sleeve 3 is larger than the outer diameter of the annular protrusion 11, and the inner diameter of the outer end of the lifting sleeve 3 is smaller than the outer diameter of the annular protrusion 11. The lifting sleeve 3 is fitted outside the main shaft 1, and the two lifting sleeves 3 are located on both sides of the connecting plate 2. The inner end of the lifting sleeve 3 is fixedly connected to the end face of the connecting plate 2. The inner edge of the blade 4 is fixedly connected to the surface of the lifting sleeve 3. The multiple blades 4 under the jurisdiction of a single three-dimensional flow impeller device are distributed circumferentially. The blade cover plate 5 is fitted outside the main shaft 1, and the two blade cover plates 5 are located on both sides of the connecting plate 2. The contour of the inner wall of the blade cover plate 5 is set to follow the shape of the outer edge of the blade 4. The inner wall of the blade cover plate 5 is fixedly connected to the outer edge of the corresponding blade 4. The main shaft 1 is provided with two threaded sections. The two threaded sections correspond to the outer ports of the two three-dimensional flow impeller devices. The two locking nuts 6 are threadedly connected to the two threaded sections. The locking nuts 6 are in contact with the outer end face of the corresponding lifting sleeve 3. The two locking nuts 6 clamp the two three-dimensional flow impeller devices.

[0026] The lifting sleeve 3, blade 4, and blade cover plate 5 are all single-piece components. The lifting sleeve 3 is composed of an inner section 31 and an outer section 32. The junction of the inner section 31 and the outer section 32 is called the interface 33. The interface 33 is distributed circumferentially along the lifting sleeve 3, and the inner diameter of the interface 33 is larger than the outer diameter of the annular protrusion 11. The blade cover plate 5 is composed of an inner plate 51 and an outer plate 52. The junction of the inner plate 51 and the outer plate 52 is called the connection port 53. The connection port 53 is distributed circumferentially along the blade cover plate 5, and the inner diameter of the connection port 53 is larger than the outer diameter of the annular protrusion 11. The single blade 4 is composed of an inner piece 41 and an outer piece 42. The junction of the inner piece 41 and the outer piece 42 is called the contact surface 43. The inner end of the contact surface 43 corresponds to the interface 33, and the outer end of the contact surface 43 corresponds to the connection port 53. The contact surface 43 is a plane.

Claims

1. A double-suction three-dimensional flow impeller assembly for a large high-temperature centrifugal fan, characterized in that: The double-suction three-dimensional impeller assembly includes: a main shaft (1), a connecting disc (2), and two sets of three-dimensional impeller devices; the three-dimensional impeller device consists of an arc-lifting sleeve (3), multiple blades (4), a blade cover plate (5), and a locking nut (6); the two sets of three-dimensional impeller devices are symmetrical in structure; The main shaft (1) has an integral annular protrusion (11) in the middle, and multiple connecting holes are provided on the annular protrusion (11); the connecting plate (2) has a through hole in the middle, and multiple bolt holes are provided around the through hole; the main shaft (1) is fitted in the through hole, and the end face of the connecting plate (2) contacts the end face of the annular protrusion (11); bolts are provided in the connecting hole and bolt holes to lock the connecting plate (2) and the annular protrusion (11); The lifting sleeve (3) is a trumpet-shaped structure. The inner diameter of the inner end of the lifting sleeve (3) is larger than the outer diameter of the annular protrusion (11), and the inner diameter of the outer end of the lifting sleeve (3) is smaller than the outer diameter of the annular protrusion (11). The lifting sleeve (3) is fitted over the main shaft (1). The two lifting sleeves (3) are located on both sides of the connecting plate (2). The inner end of the lifting sleeve (3) is fixedly connected to the end face of the connecting plate (2). The inner edge of the blade (4) is fixedly connected to the surface of the lifting sleeve (3). The multiple blades (4) under the control of the single three-dimensional flow impeller device are distributed circumferentially. The blade cover plate (5) is fitted over the main shaft (1). 1) Outside, two blade cover plates (5) are located on both sides of the connecting plate (2). The outline of the inner wall of the blade cover plate (5) is set to follow the shape of the outer edge of the blade (4). The inner wall of the blade cover plate (5) is fixedly connected to the outer edge of the corresponding blade (4). Two threaded sections are provided on the main shaft (1). The two threaded sections correspond to the outer ports of the two sets of three-dimensional flow impeller devices. Two locking nuts (6) are threadedly connected to the two threaded sections. The locking nuts (6) are in contact with the outer end face of the corresponding lifting sleeve (3). The two locking nuts (6) clamp the two sets of three-dimensional flow impeller devices. The lifting sleeve (3), blade (4), and blade cover plate (5) are all single-piece components; the lifting sleeve (3) is composed of an inner section (31) and an outer section (32), and the junction of the inner section (31) and the outer section (32) is called the interface (33). The interface (33) is distributed circumferentially along the lifting sleeve (3), and the inner diameter of the interface (33) is larger than the outer diameter of the annular protrusion (11); the blade cover plate (5) is composed of an inner plate (51) and an outer plate (52), and the junction of the inner plate (51) and the outer plate (52) is called the interface (33). The connection port (53) is located at the circumference of the blade cover plate (5). The inner diameter of the connection port (53) is larger than the outer diameter of the annular protrusion (11). A single blade (4) is made up of an inner piece (41) and an outer piece (42). The junction of the inner piece (41) and the outer piece (42) is called the contact surface (43). The inner end of the contact surface (43) corresponds to the interface (33), and the outer end of the contact surface (43) corresponds to the connection port (53). The contact surface (43) is a plane. A bushing (9) made of lightweight material is installed in the inner hole of the lifting sleeve (3), and the bushing (9) is fitted on the main shaft (1).

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