Centrifugal supercharger
The centrifugal booster fan, with its multi-stage series structure and guide section design, solves the problems of high outlet total pressure and high noise in traditional fans at low air volume, achieving a small size, low noise, and high efficiency fan design, suitable for special air supply occasions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHANGJIAGANG YINDELI AIR CONDITIONER BLOWER FAN CO LTD
- Filing Date
- 2025-09-02
- Publication Date
- 2026-07-14
AI Technical Summary
Traditional centrifugal fans struggle to achieve high outlet pressure at low air volumes and suffer from excessive noise, large size, and high energy consumption, failing to meet the needs of special air supply applications.
The centrifugal booster fan adopts a multi-stage series structure. By setting multiple pre-stage booster housings in series with the final stage volute, and using multi-stage impellers to pressurize the gas step by step, combined with the design of the guide section and collector, it can achieve stable gas introduction and efficient pressurization.
It achieves a high outlet total pressure of 900-1000Pa with a small air volume, reduces noise and overall size, improves efficiency, and is suitable for use in situations where installation space is limited.
Smart Images
Figure CN224496809U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of ventilation fan technology, specifically to centrifugal booster fans. Background Technology
[0002] Centrifugal fans, as gas conveying equipment, are widely used in many industrial and civil fields. Currently, the demand for gas conveying equipment in various fields is diverse. For example, in some special air supply applications, a high outlet total pressure (900-1000Pa) is required at a small air volume (1000-1500m3 / hour).
[0003] Traditional air compressors can generate high pressure, but they have problems such as difficulty in accurately controlling excessively high pressure and excessive noise during operation, which cannot meet the needs of such special occasions.
[0004] Traditional single-stage centrifugal fans can only achieve an outlet total pressure of 600-700 Pa at low air volumes (1000-1500 m³ / h). To meet the requirements of low air volume and high outlet total pressure, traditional single-stage centrifugal fans often need to increase the impeller diameter or rotational speed, which leads to increased radial dimensions, energy consumption, and more pronounced noise issues. Therefore, developing a centrifugal fan that can balance small size, low speed, low noise, and high outlet total pressure has become an urgent problem to be solved. Utility Model Content
[0005] The purpose of this invention is to provide a centrifugal booster fan that can take into account small size, low speed, low noise, and high outlet total pressure under small air volume.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: a centrifugal booster fan, comprising a final stage booster volute, a final stage axial air inlet provided on the front side plate of the final stage booster volute, a tangential air outlet provided on the circumferential volute wall of the final stage booster volute, a final stage impeller driven to rotate by a drive mechanism housed in the volute cavity of the final stage booster volute, at least one internally hollow and circumferentially closed pre-stage booster housing coaxially provided on the air inlet side of the final stage booster volute, a pre-stage axial air inlet and a pre-stage axial air outlet provided at the front and rear ends of each pre-stage booster housing, and a pre-stage impeller driven to rotate by a drive mechanism housed inside each pre-stage booster housing;
[0007] When there is only one pre-stage booster housing, the pre-stage axial air outlet of the pre-stage booster housing is directly connected to and communicates with the final-stage axial air inlet of the final-stage booster volute, so that the pre-stage booster housing and the final-stage booster volute are connected in series.
[0008] When there are multiple pre-stage supercharger housings, each pre-stage supercharger housing is arranged sequentially from front to back along the air intake direction. In each pair of adjacent pre-stage supercharger housings, the front axial air outlet of the front pre-stage supercharger housing is directly connected to and communicates with the front axial air inlet of the rear pre-stage supercharger housing, so that each pre-stage supercharger housing is connected in series along the air intake direction. Furthermore, the front axial air outlet of the last pre-stage supercharger housing along the air intake direction is directly connected to and communicates with the final axial air inlet of the final supercharger housing, so that each pre-stage supercharger housing and the final supercharger housing are connected in series.
[0009] Furthermore, in the aforementioned centrifugal booster fan, the drive mechanism includes a motor and a shaft. The shaft coaxially passes through the final stage booster volute and all the preceding stage booster housings. The final stage impeller in the final stage booster volute and the preceding stage impellers in each preceding stage booster housing are simultaneously mounted and fixed on the shaft. The output shaft of the motor is connected to the shaft to drive the shaft and each impeller to rotate.
[0010] Furthermore, in the aforementioned centrifugal booster fan, the pre-stage booster housing consists of a front section and a rear section. The rear section is a guide section and is a conical shape that is circumferentially closed and whose diameter gradually decreases from front to back along the air inlet direction. The small-diameter cylinder opening of the rear section constitutes the pre-stage axial air outlet of the pre-stage booster housing. The front section is a cylindrical shape that is circumferentially closed and open at both ends. The rear opening of the front section is connected to the large-diameter cylinder opening of the rear section. A front end plate is provided at the front opening of the front section, and an orifice is provided at the center of the front end plate. This orifice constitutes the pre-stage axial air inlet of the pre-stage booster housing.
[0011] Furthermore, in the aforementioned centrifugal booster fan, the pre-stage booster housing is integrally molded.
[0012] Furthermore, in the aforementioned centrifugal booster fan, a collector is coaxially arranged at the final stage axial air inlet of the final stage booster casing and at the pre-stage axial air inlet of each pre-stage booster casing.
[0013] Furthermore, in the aforementioned centrifugal booster fan, the collector is composed of a funnel-shaped guide section and an annular mounting section arranged along the edge of the large-diameter end of the guide section. The annular mounting section is used to coaxially connect with the axial air inlet of the corresponding housing. The guide section extends along the air inlet direction and is close to the inlet of the impeller inside the corresponding housing.
[0014] The beneficial effects of implementing the above technical solution are as follows:
[0015] (1) Multi-stage series pressurization: By connecting at least one pre-stage pressurization unit and one final stage volute pressurization unit in axial series, the gas is pressurized step by step; each impeller does work on the gas, and finally accumulates at the fan outlet to generate a high outlet total pressure (900-1000Pa) that is difficult to achieve by traditional single-stage fans. Moreover, through multi-stage cooperation, high outlet total pressure can be obtained without simply increasing the diameter of a single-stage impeller or significantly increasing the speed. This fundamentally avoids the problems of excessive overall radial size and high noise caused by high speed and large impeller size. Under the same impeller diameter and speed conditions, it can obtain higher air pressure than traditional single-stage fans. It achieves an outlet total pressure of 900-1000Pa at a small air volume of 1000-1500m3 / hour while taking into account small size, low speed and low noise. It perfectly meets the requirements of small air volume and high pressure in special working conditions.
[0016] (2) The structure is simple and compact, saving a lot of space: the stages are directly axially connected, which reduces pressure loss and eliminates intermediate connecting pipes. This completely eliminates the complex connecting pipes between stages of traditional multi-stage independent fans, avoiding the large and bulky layout caused by the detour of pipes in traditional multi-stage independent fans. Furthermore, since there is no need to provide space for large single-stage impellers, the radial dimensions of the whole machine can be effectively controlled. This structure is particularly suitable for use in situations where installation space is limited.
[0017] (3) The number of pre-charger housings can be flexibly increased or decreased according to the required final pressure, while the overall structure remains unchanged, and the design is highly expandable.
[0018] (4) The guide section design of the front-stage booster housing can make the messy and swirling airflow from the impeller smooth and uniform in direction, providing near-ideal air intake conditions for the next stage impeller. The next stage impeller does not need to overcome the turbulence and pre-swirl of the incoming flow, so it can work efficiently at its design point and improve the overall efficiency. At the same time, the streamlined collector at the air inlet can smoothly guide the gas into the impeller, reduce the intake resistance loss, and further improve the efficiency of the single stage and the whole machine.
[0019] (5) Low speed operation: Due to the use of multi-stage boosting, there is no need to rely on high speed to obtain high pressure, so the mechanical noise and aerodynamic noise generated by the impeller rotation are also significantly reduced.
[0020] (6) Single-shaft drive system: All impellers are fixed on the same shaft and driven by a single motor. This structure simplifies the transmission system and significantly improves the reliability and lifespan of the equipment. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the centrifugal booster fan described in Embodiment 1 of this utility model.
[0022] Figure 2 for Figure 1 The right view.
[0023] Figure 3 for Figure 1 The diagram shows a structural schematic of the AA cross-section.
[0024] Figure 4 This is a perspective view of the centrifugal booster fan described in Embodiment 1 of this utility model.
[0025] Figure 5 This is a perspective view of the centrifugal booster fan described in Embodiment 1 of this utility model.
[0026] Figure 6 This is a three-dimensional cross-sectional view of the centrifugal booster fan described in Embodiment 1 of this utility model.
[0027] Figure 7 This is a schematic diagram of the air collector.
[0028] Figure 8 This is a schematic diagram of the pre-charger housing.
[0029] Figure 9 This is a schematic diagram of the centrifugal booster fan described in Embodiment 2 of this utility model.
[0030] Figure 10 for Figure 9 The diagram shows a structural schematic of the BB cross-section.
[0031] Figure 11 for Figure 9 The right view.
[0032] Figure 12 This is a three-dimensional cross-sectional view of the centrifugal booster fan described in Embodiment 2 of this utility model. Detailed Implementation
[0033] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Example 1
[0034] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8As shown, the centrifugal booster fan includes a final-stage booster volute 21. A final-stage axial air inlet 23 is provided on the front side plate 22 of the final-stage booster volute 21. A tangential air outlet 24 is provided on the circumferential volute wall of the final-stage booster volute 21. A final-stage impeller 26, driven to rotate by a drive mechanism, is housed in the volute cavity 25 of the final-stage booster volute 21. A hollow, circumferentially closed pre-stage booster housing 31 is coaxially arranged on the air inlet side of the final-stage booster volute 21. The front end of the device is provided with a front-stage axial air inlet 33 that connects to its inner cavity 32, and the rear end of the front-stage booster housing 31 is provided with a front-stage axial air outlet 34 that connects to its inner cavity 32. The inner cavity 32 of the front-stage booster housing 31 houses a front-stage impeller 35 that is driven to rotate by a drive mechanism. The front-stage axial air outlet 34 of the front-stage booster housing 31 is directly coaxially connected to and connected to the final-stage axial air inlet 23 of the final-stage booster volute 21, so that the front-stage booster housing 31 and the final-stage booster volute 21 are connected in series.
[0035] In this embodiment, the drive mechanism includes a motor 4 and a shaft 1. The shaft 1 is coaxially connected to the final stage booster volute 21 and the first stage booster housing 31. The final stage impeller 26 in the final stage booster volute 21 and the first stage impeller 35 in the first stage booster housing 31 are simultaneously mounted and fixed on the shaft 1. The output shaft of the motor 4 is coaxially connected to the shaft 1 to drive the shaft 1 and each impeller to rotate.
[0036] In this embodiment, as Figure 8 As shown, the pre-charger housing 31 is composed of a front section 311 and a rear section 312, and the pre-charger housing is integrally formed. The rear section 312 is a guide section, which is a conical shape that is circumferentially closed and whose diameter gradually decreases from front to back along the air intake direction. The small diameter opening of the rear section 312 forms the front axial air outlet 34 of the pre-charger housing 31. The front section 311 is a cylindrical shape that is circumferentially closed and open at both ends. The rear opening of the front section 311 is connected to the large diameter opening of the rear section 312. A front end plate 313 is provided at the front opening of the front section 311, and an orifice is provided at the center of the front end plate 313. This orifice forms the front axial air inlet 33 of the pre-charger housing 31.
[0037] In this embodiment, a collector 5 is coaxially arranged at the final stage axial air inlet 23 of the final stage booster housing 21 and at the pre-stage axial air inlet 33 of each pre-stage booster housing 31. Figure 7As shown, the collector 5 consists of a funnel-shaped guide section 52 and an annular mounting section 51 arranged along the edge of the large-diameter end of the guide section 52. The annular mounting section 51 is used to coaxially connect with the axial air inlet of the corresponding housing. The guide section 52 extends along the air inlet direction and is close to the inlet of the impeller inside the corresponding housing. The inner wall surface of the guide section is a smooth and continuous streamlined curved surface. The design of the collector can accelerate and guide the axial incoming flow to the inlet area of the corresponding impeller without impact and reduce the intake vortex loss.
[0038] In this embodiment, the specific series connection structure of the final stage booster volute 21 and the pre-stage booster housing 31 is as follows: the pre-stage axial air outlet 34 of the pre-stage booster housing 31 is directly coaxially connected and connected to the final stage axial air inlet 23 of the final stage booster volute 21, so that the final stage booster volute 21 and the pre-stage booster housing 31 are connected in series as a whole, wherein the pre-stage axial air inlet 34 of the pre-stage booster housing 31 is the total air inlet of the entire fan.
[0039] In this embodiment, the final stage impeller 26 and the preceding stage impeller 35 have the same structure and are both commercially available mature products. Their core function is to transfer energy by applying centrifugal force to the gas through rotation, so their structure will not be described in detail here.
[0040] During operation, the motor 4 is started, and the motor 4 drives the coaxially connected machine shaft 1 to rotate through the output shaft, thereby driving the front impeller 35 and the last impeller 26 to rotate synchronously at high speed. Since the front impeller 35 and the last impeller 26 are rigidly connected coaxially, they always maintain the same speed, ensuring the continuity and stability of gas flow between stages.
[0041] (1) Pre-stage boosting process:
[0042] When the front impeller 35 rotates, it does work on the gas inside, thereby creating a negative pressure in the inlet area of the front impeller. Under this negative pressure, the ambient atmospheric pressure gas is drawn in and, through the guiding effect of the collector 5, enters the front impeller 35 evenly and smoothly without impact. Under the centrifugal force of the impeller rotation, the gas entering the front impeller 35 is thrown at high speed from the impeller blade gap into the inner cavity 32 of the front booster housing 31. After entering the inner cavity 32, most of the kinetic energy of the high-speed airflow is effectively converted into static pressure, forming a primary booster gas that has undergone preliminary boosting. This primary booster gas is directionally output from the front axial outlet 34 through the guide section (the rear section 312 of the front booster housing 31).
[0043] Since the rear section of the pre-stage booster housing 31 is a guide section with a cross-sectional area that gradually decreases along the gas flow direction, the gas velocity will be further increased when passing through the guide section. The increased velocity accumulates more kinetic energy, ensuring that the gas entering the final stage has sufficient initial kinetic energy. It also makes the airflow from the pre-stage impeller 35 smooth and uniform in direction, providing near-ideal intake conditions for the next stage impeller.
[0044] (2) Final stage boosting and output process:
[0045] When the final stage impeller 26 rotates synchronously, it does work on the gas inside, thereby creating a negative pressure in the inlet area of the final stage impeller 26. Under the dual drive of this negative pressure and the high flow rate of the primary pressurized gas, the primary pressurized gas discharged from the axial outlet 34 of the front stage smoothly enters the final stage impeller 26 through the collector 5. Under the action of the centrifugal force of the rotation of the final stage impeller 26, the final stage impeller 26 continuously does work on the incoming primary pressurized gas, further increasing the kinetic energy and pressure of the gas. The final stage impeller throws the primary pressurized gas at high speed from its blade gaps into the volute cavity 25 of the final stage volute 21. In the volute cavity 25 with a gradually expanding cross section, the high-speed airflow follows the design law of the volute, and a large amount of kinetic energy is efficiently converted into pressure energy, finally forming a high static pressure gas with stable pressure, which is finally stably discharged from the tangential outlet 24 of the final stage volute 21. Example 2
[0046] The only difference between this embodiment 2 and embodiment 1 is the number of pre-charger housings; in this embodiment 2, there are two pre-charger housings.
[0047] like Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown, the centrifugal booster fan includes a final stage booster volute 21. A final stage axial air inlet 23 is provided on the front side plate 22 of the final stage booster volute 21. A tangential air outlet 24 is provided on the circumferential volute wall of the final stage booster volute 21. A final stage impeller 26 driven to rotate by a drive mechanism is housed in the volute cavity 25 of the final stage booster volute 21. Two hollow and circumferentially closed pre-stage booster housings are coaxially arranged on the air inlet side of the final stage booster volute 21. The two pre-stage booster units are defined as the first stage pre-stage booster housing 3001 and the second stage pre-stage booster housing 3011 from front to back along the air inlet direction.
[0048] A first-stage pre-stage axial air inlet 3003 communicating with its first-stage inner cavity 3002 is provided at the front end of the first-stage pre-stage booster housing 3001, and a first-stage pre-stage axial air outlet 3004 communicating with its first-stage inner cavity 3002 is provided at the rear end of the first-stage pre-stage booster housing 3001. A first-stage pre-stage impeller 3005 is housed in the first-stage inner cavity 3002 of the first-stage pre-stage booster housing 3001.
[0049] like Figure 10 As shown, the first-stage pre-stage booster housing 3001 is composed of a front section 311 and a rear section 312, and the first-stage pre-stage booster housing 3001 is integrally formed. The rear section 312 is a guide section, which is a conical shape that is circumferentially closed and whose diameter gradually decreases from front to back along the air inlet direction. The small-diameter opening of the rear section 312 constitutes the first-stage pre-stage axial air outlet 3004 of the first-stage pre-stage booster housing 3001. The front section 311 is a cylindrical shape that is circumferentially closed and open at both ends. The rear opening of the front section 311 is connected to the large-diameter opening of the rear section 312. A front end plate 313 is provided at the front opening of the front section 311, and an orifice is provided at the center of the front end plate 313. This orifice constitutes the first-stage pre-stage axial air inlet 3003 of the first-stage pre-stage booster housing 3001.
[0050] The second-stage pre-stage booster housing 3011 has a second-stage pre-stage axial air inlet 3013 that communicates with its second-stage inner cavity 3012 at its front end, and a second-stage pre-stage axial air outlet 3014 that communicates with its second-stage inner cavity 3012 at its rear end. The second-stage pre-stage impeller 3015 is housed in the second-stage inner cavity 3012 of the second-stage pre-stage booster housing 3011.
[0051] like Figure 10 As shown, the second-stage pre-stage booster housing 3011 is composed of a front section 311 and a rear section 312, and the second-stage pre-stage booster housing 3011 is integrally formed. The rear section 312 is a guide section, which is a conical shape that is circumferentially closed and whose diameter gradually decreases from front to back along the air inlet direction. The small-diameter opening of the rear section 312 constitutes the second-stage pre-stage axial air outlet 3014 of the second-stage pre-stage booster housing 3011. The front section 311 is a cylindrical shape that is circumferentially closed and open at both ends. The rear opening of the front section 311 is connected to the large-diameter opening of the rear section 312. A front end plate 313 is provided at the front opening of the front section 311, and an orifice is provided at the center of the front end plate 313. This orifice constitutes the second-stage pre-stage axial air inlet 3013 of the second-stage pre-stage booster housing 3011.
[0052] In this embodiment, the drive mechanism includes a motor 4 and a shaft 1. The shaft 1 is coaxially connected to a final stage booster volute 21, a second stage pre-booster housing 3011, and a first stage pre-booster housing 3001. The final stage impeller 26 in the final stage booster volute 21, the second stage pre-booster impeller 3015 in the second stage pre-booster housing 3011, and the first stage pre-booster impeller 3005 in the first stage pre-booster housing 3001 are simultaneously mounted and fixed on the shaft 1. The output shaft of the motor 4 is coaxially connected to the shaft 1 to drive the shaft 1 and each impeller to rotate.
[0053] In this embodiment, a collector 5 is coaxially arranged at the final stage axial air inlet 23 of the final stage booster housing 21, the first stage pre-boost axial air inlet 3003 of the first stage pre-boost housing 3001, and the second stage pre-boost axial air inlet 3013 of the second stage pre-boost housing 3011. Figure 7 As shown, the collector 5 consists of a funnel-shaped flow guide 52 and an annular mounting part 51 arranged along the edge of the large-diameter end of the flow guide 52. The annular mounting part 51 is used to coaxially connect with the axial air inlet of the corresponding housing. The flow guide 52 extends along the air inlet direction and is close to the inlet of the impeller inside the corresponding housing. The inner wall surface of the flow guide is a smooth and continuous streamlined curved surface. The design of the collector can accelerate and guide the axial flow to the inlet area of the corresponding impeller without impact and uniformly.
[0054] In this embodiment, the specific series connection structure between the final stage booster housing 21, the first stage pre-boost housing 3001, and the second stage pre-boost housing 3011 is as follows: the first stage pre-boost axial air outlet 3004 of the first stage pre-boost housing 3001 is directly coaxially connected to and connected to the second stage pre-boost axial air inlet 3013 of the second stage pre-boost housing 3011; the second stage pre-boost axial air outlet 3014 of the second stage pre-boost housing 3011 is directly coaxially connected to and connected to the final stage axial air inlet 23 of the final stage booster housing 21, so that the final stage booster housing 21, the second stage pre-boost housing 3011, and the first stage pre-boost housing 3001 are connected in series to form a whole, wherein the first stage pre-boost axial air inlet 3003 of the first stage pre-boost housing 3001 is the total air inlet of the entire fan.
[0055] In this embodiment, the final stage impeller 26, the first stage pre-stage impeller 3005, and the second stage pre-stage impeller 3015 have the same structure and are all commercially available mature products. Their core function is to transfer energy by applying centrifugal force to the gas through rotation, so their structure will not be described in detail here.
[0056] During operation, the motor 4 is started, and the motor 4 drives the coaxially connected machine shaft 1 to rotate through the output shaft, thereby driving the first stage pre-stage impeller 3005, the second stage pre-stage impeller 3015 and the final stage impeller 26 to rotate synchronously at high speed. Since the first stage pre-stage impeller 3005, the second stage pre-stage impeller 3015 and the final stage impeller 26 are rigidly connected coaxially, each impeller always maintains the same speed, ensuring the continuity and stability of gas flow between stages;
[0057] (1) First-stage boosting process:
[0058] When the first-stage pre-stage impeller 3005 rotates, it does work on the gas inside, thereby creating a negative pressure in the inlet area of the first-stage pre-stage impeller 3005. Under this negative pressure, ambient atmospheric gas is drawn in and, through the guiding effect of the collector 5, enters the first-stage pre-stage impeller 3005 evenly and smoothly without impact. Under the centrifugal force of the impeller rotation, the gas entering the first-stage pre-stage impeller 3005 is thrown at high speed from the impeller blade gap into the first-stage inner cavity 3002 of the first-stage pre-stage pressurization housing 3001. After entering the first-stage inner cavity 3002, most of the kinetic energy of the high-speed airflow is effectively converted into static pressure, forming a first-stage pressurized gas that has undergone preliminary pressurization. This first-stage pressurized gas is directionally output from the first-stage pre-stage axial outlet 3004 through the guide section (the rear section 312 of the first-stage pre-stage pressurization housing).
[0059] Since the rear section of the first-stage pre-stage booster housing 3001 is a guide section with a cross-sectional area that gradually decreases along the gas flow direction, the gas velocity will be further increased when passing through the guide section. The increased velocity accumulates more kinetic energy, ensuring that the gas entering the final stage has sufficient initial kinetic energy. It also makes the airflow from the first-stage pre-stage impeller 3005 smooth and uniform in direction, providing near-ideal intake conditions for the next stage impeller.
[0060] (2) Secondary boosting process:
[0061] When the second-stage pre-stage impeller 3015 rotates, it does work on the gas inside, thereby creating a negative pressure in the inlet area of the second-stage pre-stage impeller 3015. Driven by the negative pressure and the high flow rate of the first-stage pressurized gas, the first-stage pressurized gas discharged from the axial outlet 3004 of the first-stage pre-stage impeller smoothly enters the second-stage pre-stage impeller 3015 through the collector 5. Under the centrifugal force of the impeller rotation, the gas entering the second-stage pre-stage impeller 3015 is thrown at high speed from the impeller blade gap into the second-stage inner cavity 3012 of the second-stage pre-stage pressurization housing 3011. After entering the second-stage inner cavity 3012, most of the kinetic energy of the high-speed airflow is further and effectively converted into static pressure, forming a second-stage pressurized gas that has been further pressurized. This second-stage pressurized gas is directionally output from the axial outlet 3014 of the second-stage pre-stage impeller through the guide section (the rear section 312 of the second-stage pre-stage pressurization housing).
[0062] Similarly, since the rear section of the second-stage pre-stage booster housing 3011 is a guide section with a cross-sectional area that gradually decreases along the gas flow direction, the gas velocity will be further increased when passing through the guide section. The increased velocity accumulates more kinetic energy, ensuring that the gas entering the final stage has sufficient initial kinetic energy. It also makes the airflow from the second-stage pre-stage impeller 3015 smooth and uniform in direction, providing near-ideal intake conditions for the next stage impeller.
[0063] (3) Final stage boosting and output process:
[0064] When the final stage impeller 26 rotates synchronously, it does work on the gas inside, thereby creating a negative pressure in the inlet area of the final stage impeller 26. Under the dual drive of this negative pressure and the high flow rate of the primary pressurized gas, the primary pressurized gas discharged from the axial outlet 34 of the front stage smoothly enters the final stage impeller 26 through the collector 5. Under the action of the centrifugal force of the rotation of the final stage impeller 26, the final stage impeller 26 continuously does work on the incoming primary pressurized gas, further increasing the kinetic energy and pressure of the gas. The final stage impeller throws the primary pressurized gas at high speed from its blade gaps into the volute cavity 25 of the final stage volute 21. In the volute cavity 25 with a gradually expanding cross section, the high-speed airflow follows the design law of the volute, and a large amount of kinetic energy is efficiently converted into pressure energy, finally forming a high static pressure gas with stable pressure, which is finally stably discharged from the tangential outlet 24 of the final stage volute 21.
[0065] The advantages of this utility model are:
[0066] (1) Multi-stage series pressurization: By connecting at least one pre-stage pressurization unit and one final stage volute pressurization unit in axial series, the gas is pressurized step by step; each impeller does work on the gas, and finally accumulates at the fan outlet to generate a high outlet total pressure (900-1000Pa) that is difficult to achieve by traditional single-stage fans. Moreover, through multi-stage cooperation, high outlet total pressure can be obtained without simply increasing the diameter of a single-stage impeller or significantly increasing the speed. This fundamentally avoids the problems of excessive overall radial size and high noise caused by high speed and large impeller size. Under the same impeller diameter and speed conditions, it can obtain higher air pressure than traditional single-stage fans. It achieves an outlet total pressure of 900-1000Pa at a small air volume of 1000-1500m3 / hour while taking into account small size, low speed and low noise. It perfectly meets the requirements of small air volume and high pressure in special working conditions.
[0067] (2) The structure is simple and compact, saving a lot of space: the stages are directly axially connected, which reduces pressure loss and eliminates intermediate connecting pipes. This completely eliminates the complex connecting pipes between stages of traditional multi-stage independent fans, avoiding the large and bulky layout caused by the detour of pipes in traditional multi-stage independent fans. Furthermore, since there is no need to provide space for large single-stage impellers, the radial dimensions of the whole machine can be effectively controlled. This structure is particularly suitable for use in situations where installation space is limited.
[0068] (3) The number of pre-charger housings can be flexibly increased or decreased according to the required final pressure, while the overall structure remains unchanged, and the design is highly expandable.
[0069] (4) The guide section design of the front-stage booster housing can make the messy and swirling airflow from the impeller smooth and uniform in direction, providing near-ideal air intake conditions for the next stage impeller. The next stage impeller does not need to overcome the turbulence and pre-swirl of the incoming flow, so it can work efficiently at its design point and improve the overall efficiency. At the same time, the streamlined collector at the air inlet can smoothly guide the gas into the impeller, reduce the intake resistance loss, and further improve the efficiency of the single stage and the whole machine.
[0070] (5) Low speed operation: Due to the use of multi-stage boosting, there is no need to rely on high speed to obtain high pressure, so the mechanical noise and aerodynamic noise generated by the impeller rotation are also significantly reduced.
[0071] (6) Single-shaft drive system: All impellers are fixed on the same shaft and driven by a single motor. This structure simplifies the transmission system and significantly improves the reliability and lifespan of the equipment.
[0072] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any modifications or equivalent changes made based on the technical essence of the present utility model shall still fall within the scope of protection claimed by the present utility model.
Claims
1. A centrifugal booster fan, characterized in that: The system includes a final stage booster volute, with a final stage axial air inlet on the front side plate of the final stage booster volute and a tangential air outlet on the circumferential volute wall of the final stage booster volute. A final stage impeller driven by a drive mechanism is housed in the volute cavity of the final stage booster volute. At least one hollow and circumferentially closed pre-stage booster housing is coaxially arranged on the air inlet side of the final stage booster volute. A pre-stage axial air inlet and a pre-stage axial air outlet are respectively provided at the front and rear ends of each pre-stage booster housing. A pre-stage impeller driven by a drive mechanism is housed inside each pre-stage booster housing. When there is only one pre-stage booster housing, the pre-stage axial air outlet of the pre-stage booster housing is directly connected to and communicates with the final-stage axial air inlet of the final-stage booster volute, so that the pre-stage booster housing and the final-stage booster volute are connected in series. When there are multiple pre-stage supercharger housings, each pre-stage supercharger housing is arranged sequentially from front to back along the air intake direction. In each pair of adjacent pre-stage supercharger housings, the front axial air outlet of the front pre-stage supercharger housing is directly connected to and communicates with the front axial air inlet of the rear pre-stage supercharger housing, so that each pre-stage supercharger housing is connected in series along the air intake direction. Furthermore, the front axial air outlet of the last pre-stage supercharger housing along the air intake direction is directly connected to and communicates with the final axial air inlet of the final supercharger housing, so that each pre-stage supercharger housing and the final supercharger housing are connected in series.
2. The centrifugal booster fan according to claim 1, characterized in that: The drive mechanism includes a motor and a shaft. The shaft coaxially passes through the final stage booster volute and all the preceding stage booster housings. The final stage impeller in the final stage booster volute and the preceding stage impellers in each preceding stage booster housing are simultaneously mounted and fixed on the shaft. The output shaft of the motor is connected to the shaft to drive the shaft and each impeller to rotate.
3. The centrifugal booster fan according to claim 1, characterized in that: The pre-charger housing consists of a front section and a rear section. The rear section is a guide section and is a conical shape that is circumferentially closed and has a diameter that gradually decreases from front to back along the air intake direction. The small-diameter cylinder inlet of the rear section forms the front-stage axial air outlet of the pre-charger housing. The front section is a cylindrical shape that is circumferentially closed and open at both ends. The rear opening of the front section is connected to the large-diameter cylinder inlet of the rear section. A front end plate is provided at the front opening of the front section, and an orifice is provided at the center of the front end plate. This orifice forms the front-stage axial air inlet of the pre-charger housing.
4. The centrifugal booster fan according to claim 3, characterized in that: The pre-charger housing is integrally molded.
5. The centrifugal booster fan according to claim 1, characterized in that: A collector is coaxially installed at the final stage axial air inlet of the final stage supercharger housing and at the pre-stage axial air inlet of each pre-stage supercharger housing.
6. The centrifugal booster fan according to claim 5, characterized in that: The collector consists of a funnel-shaped flow guide and an annular mounting portion along the edge of the large-diameter end of the flow guide. The annular mounting portion is used to coaxially connect with the axial air inlet of the corresponding housing. The flow guide extends along the air inlet direction and is close to the inlet of the impeller inside the corresponding housing.