Coaxial and same-side tandem double-impeller centrifugal fan and fluid pressurization and delivery method thereof

Abstract

This invention discloses a coaxial, side-connected, series-connected dual-impeller centrifugal fan and its fluid pressurization and conveying method, including a primary pressurizing impeller and a secondary pressurizing impeller; a baffle plate is fixed inside the primary impeller casing, and multiple arc-shaped guide plates are fixed on the side of the baffle plate facing the fluid outlet of the primary impeller casing; a circular arc noise-reducing flow channel is formed between the baffle plate, an integrally formed volute inside the primary impeller casing, each arc-shaped guide plate, and the arc-shaped inner wall of the primary impeller casing; the volute has a guide channel, one end of which is connected to the fluid inlet of the guide channel; the fluid outlet of the guide channel is connected to the fluid outlet of the primary impeller casing through an arc-shaped flow channel, and the side of the arc-shaped noise-reducing flow channel is connected to the fluid outlet of the primary impeller casing through the remaining arc-shaped flow channels. This invention pressurizes the impeller through two stages of pressurization, and significantly reduces the noise and energy loss of the primary pressurization stage by relying on the arc-shaped noise-reducing flow channel and the arc-shaped flow channel, thereby delivering high pressure.

Description

Technical Field

[0001] This invention belongs to the field of centrifugal fan technology, specifically relating to a coaxial, same-side series-connected double-impeller centrifugal fan and its fluid pressurization and conveying method. Background Technology

[0002] Centrifugal fans are machines that rely on input mechanical energy to increase gas pressure and discharge gas. Existing single-outlet centrifugal fans are all single-impeller centrifugal fans, limiting their ability to further increase pressure. While existing single-motor dual-impeller centrifugal fans have dual inlet and dual outlet channels, their initial design aimed to provide dual outlet channels using only one motor and controller, thus saving costs. However, each pair of inlet and outlet channels also uses only one impeller, still resulting in insufficient pressure. Therefore, achieving pressure exceeding the requirements of each inlet or outlet channel using a single impeller in a centrifugal fan remains a significant challenge. Summary of the Invention

[0003] The problem this invention aims to solve is to address the shortcomings of existing technologies by providing a coaxial, same-side, series-connected double-impeller centrifugal fan and its fluid pressurization and conveying method.

[0004] The technical solution adopted in this invention is as follows:

[0005] This invention relates to a coaxial, side-connected, series-connected dual-impeller centrifugal fan, comprising an input shaft, an inlet channel, a primary impeller housing, a primary booster impeller, a secondary impeller housing, a secondary booster impeller, and an outlet channel. Both the primary and secondary impeller housings are fixed to a support. The inlet channel is fixed to the primary impeller housing, and the outlet channel is fixed to the secondary impeller housing. The fluid outlet of the inlet channel communicates with the fluid inlet of the primary impeller housing, the fluid outlet of the primary impeller housing communicates with the fluid inlet of the secondary impeller housing, and the fluid outlet of the secondary impeller housing communicates with the fluid inlet of the outlet channel. The input shaft passes through the central holes of the inlet channel, the primary impeller housing, and the secondary impeller housing, and both ends of the input shaft are supported by bearings on a bearing seat. The bearing seat is fixed to the support. The primary booster impeller is placed inside the primary impeller housing, and the secondary booster impeller is placed inside the secondary impeller housing; both the primary and secondary booster impellers are fixed to the input shaft.

[0006] A baffle plate is fixed inside the first-stage impeller housing, and the baffle plate is closer to the second-stage impeller housing than the first-stage booster impeller. Multiple arc-shaped guide plates are fixed on the side of the baffle plate opposite the fluid outlet of the first-stage impeller housing, and an arc-shaped flow channel is formed between adjacent arc-shaped guide plates. A circular arc noise reduction flow channel is formed between the baffle plate, the integrally formed volute inside the first-stage impeller housing, each arc-shaped guide plate, and the arc-shaped inner wall of the first-stage impeller housing. The volute has a guide channel, and one end of the circular arc noise reduction flow channel is connected to the fluid inlet of the guide channel. The fluid outlet of the guide channel is connected to the fluid outlet of the first-stage impeller housing through an arc-shaped flow channel, and the side of the circular arc noise reduction flow channel is connected to the fluid outlet of the first-stage impeller housing through the other arc-shaped flow channels.

[0007] The input shaft is hollow, and a spline sleeve is fitted at the input end of the central hole of the input shaft. The outer ring of the spline sleeve has n arc-shaped grooves I evenly distributed in the circumferential direction, and the input end of the central hole of the input shaft has n arc-shaped grooves II, n≥4. Each arc-shaped groove I and an arc-shaped groove II corresponding to the circumferential position are fastened by a nylon shaft.

[0008] Preferably, sealing gaskets are provided between the fluid outlet of the inlet channel and the fluid inlet of the first-stage impeller housing, between the fluid outlet of the first-stage impeller housing and the fluid inlet of the second-stage impeller housing, and between the fluid outlet of the second-stage impeller housing and the fluid inlet of the outlet channel.

[0009] The fluid pressurization and conveying method of this coaxial, same-side series-connected double-impeller centrifugal fan is as follows:

[0010] After the motor's output shaft is connected to the spline sleeve, the motor is started, driving the spline sleeve and input shaft to rotate. The input shaft then drives the first-stage and second-stage booster impellers to rotate. The first-stage booster impeller draws fluid from the inlet channel into the first-stage impeller housing and performs first-stage boosting on the fluid. The fluid after first-stage boosting is sent to the arc-shaped noise reduction channel. The arc-shaped noise reduction channel reduces the noise and energy loss caused by the impact between the first-stage booster fluid and the inner wall of the arc surface of the first-stage impeller housing, thereby increasing the delivery pressure. Most of the fluid in the arc-shaped noise reduction channel enters the guide channel of the volute tongue with the rotation of the first-stage booster impeller, and then enters the arc-shaped channel directly connected to the guide channel. A small portion directly enters the other arc-shaped channels. The fluid in each arc-shaped channel finally converges at the fluid outlet of the first-stage impeller housing. The second-stage booster impeller draws the fluid from the fluid outlet of the first-stage impeller housing into the second-stage impeller housing and performs second-stage boosting. The fluid after second-stage boosting is then sent to the outlet channel for output.

[0011] The present invention has the following beneficial effects:

[0012] This invention connects the primary and secondary impeller housings in series directly on the same side of the motor. A single motor synchronously drives both the primary and secondary booster impellers within the primary and secondary impeller housings. The primary booster impeller pressurizes the fluid once, and the design of the arc-shaped and noise-reducing flow channels significantly reduces noise and energy loss caused by fluid impacting the arc-shaped inner wall of the primary impeller housing, thus further increasing the delivery pressure. The secondary booster impeller pressurizes the fluid once before outputting it. Furthermore, the motor's output and input shafts are connected via a self-centering spline sleeve, greatly improving the coaxiality of the motor's output and input shafts, thereby enhancing the stability and pressure of fluid delivery. In summary, compared to existing centrifugal fans that use only one impeller per pair of inlet and outlet channels and lack arc-shaped and noise-reducing flow channels, guide channels, and curved flow channels, this invention can increase the inlet pressure by more than two times. The spline sleeve achieves its self-centering effect through the deformation of the circumferentially distributed nylon shafts. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the present invention.

[0014] Figure 2 This is a schematic diagram of the external shape of the present invention.

[0015] Figure 3 for Figure 2 The right view.

[0016] Figure 4 This is a perspective view of the structure of the present invention after removing the support, inlet channel, first-stage impeller housing and bearing seat.

[0017] Figure 5 This is a two-dimensional structural diagram of the present invention after removing the support, inlet channel, first-stage impeller housing and bearing seat. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0019] like Figure 1 and Figure 2As shown, a coaxial, side-connected, series-connected double-impeller centrifugal fan includes an input shaft, an inlet channel 1, a primary impeller housing 2, a primary booster impeller 3, a secondary impeller housing 4, a secondary booster impeller 5, and an outlet channel 6. The primary impeller housing 2 and the secondary impeller housing 4 are both fixed to a support. The inlet channel 1 is fixed to the primary impeller housing 2, and the outlet channel 6 is fixed to the secondary impeller housing 4. The fluid outlet of the inlet channel 1 communicates with the fluid inlet of the primary impeller housing 2, the fluid outlet of the primary impeller housing 2 communicates with the fluid inlet of the secondary impeller housing 4, and the fluid outlet of the secondary impeller housing 4 communicates with the fluid inlet of the outlet channel 6. The input shaft passes through the central holes of the inlet channel 1, the primary impeller housing 2, and the secondary impeller housing 4, and both ends of the input shaft are supported by bearings on a bearing seat 7. The bearing seat 7 is fixed to the support. The primary booster impeller 3 is placed inside the primary impeller housing 2, and the secondary booster impeller 5 is placed inside the secondary impeller housing 4, with both the primary booster impeller 3 and the secondary booster impeller 5 fixed to the input shaft.

[0020] like Figure 4 and Figure 5 As shown, a baffle plate 8 is fixed inside the first-stage impeller housing 2, and the baffle plate 8 is closer to the second-stage impeller housing 4 than the first-stage booster impeller 3; multiple arc-shaped guide plates 9 are fixed on the side of the baffle plate 8 facing the fluid outlet of the first-stage impeller housing 2, and an arc-shaped flow channel 10 is formed between adjacent arc-shaped guide plates; a circular arc noise reduction flow channel is formed between the baffle plate 8, the integrally formed volute tongue 11 inside the first-stage impeller housing 2, each arc-shaped guide plate, and the arc-shaped inner wall of the first-stage impeller housing 2; the volute tongue 11 has a guide channel, and the circular arc... One end of the noise reduction channel is connected to the fluid inlet 12 of the guide channel; the fluid outlet of the guide channel is connected to the fluid outlet of the first-stage impeller housing 2 through an arc-shaped channel, and the side of the circular arc noise reduction channel is connected to the fluid outlet of the first-stage impeller housing 2 through other arc-shaped channels; the design of the circular arc noise reduction channel and the arc-shaped channel greatly reduces the noise of the fluid impacting the inner wall of the arc surface of the first-stage impeller housing 2 in the impeller passage of the first-stage booster impeller 3 and the resulting energy loss, thereby further improving the conveying pressure.

[0021] like Figure 1 and Figure 3 As shown, the input shaft is hollow, and a spline sleeve 13 is fitted at the input end of the central hole of the input shaft. The outer ring of the spline sleeve has n arc-shaped grooves 1 evenly distributed along the circumference, and the input end of the central hole of the input shaft has n arc-shaped grooves 24, n≥4. Each arc-shaped groove 1 and the corresponding arc-shaped groove 2 in the circumferential position are fastened by a nylon shaft, so that the spline sleeve is fixed at the input end of the central hole of the input shaft. Due to the self-aligning effect generated by the deformation of each nylon shaft, the coaxiality of the spline sleeve and the input shaft is greatly improved, thereby improving the stability of fluid transportation and fluid pressure.

[0022] In a preferred embodiment, sealing gaskets are provided between the fluid outlet of the inlet channel 1 and the fluid inlet of the first-stage impeller housing 2, between the fluid outlet of the first-stage impeller housing 2 and the fluid inlet of the second-stage impeller housing 4, and between the fluid outlet of the second-stage impeller housing 4 and the fluid inlet of the outlet channel 6 to prevent fluid leakage.

[0023] The fluid pressurization and conveying method of this coaxial, same-side series-connected double-impeller centrifugal fan is as follows:

[0024] After the motor's output shaft (with a spline) is connected to the spline sleeve, the motor is started, driving the spline sleeve and input shaft to rotate. The input shaft then drives the first-stage booster impeller 3 and the second-stage booster impeller 5 to rotate. The first-stage booster impeller 3 draws fluid from the inlet channel 1 into the first-stage impeller housing 2 and performs first-stage boosting on the fluid. The fluid, after first-stage boosting, is sent to the arc-shaped noise-reducing flow channel. The arc-shaped noise-reducing flow channel reduces the noise and energy loss caused by the impact of the first-stage boosted fluid on the arc-shaped inner wall of the first-stage impeller housing 2, thereby further... The pressure is increased step by step; most of the fluid in the arc-shaped noise reduction channel enters the guide channel of the volute tongue as the first-stage booster impeller 3 rotates, and then enters the arc-shaped channel directly connected to the guide channel. A small part directly enters the other arc-shaped channels. The fluid in each arc-shaped channel finally converges at the fluid outlet of the first-stage impeller housing 2. The second-stage booster impeller 5 draws the fluid from the fluid outlet of the first-stage impeller housing 2 into the second-stage impeller housing 4 and performs secondary boosting. The fluid after secondary boosting is then sent to the outlet channel 6 for output.

[0025] This invention achieves an air volume of 12200 m³ / min when the motor speed is 2900 r / min and the power is 46 kW. 3 / s, with an inlet pressure of up to 17800Pa. Compared to existing centrifugal fans that use only one impeller for each pair of inlet and outlet channels and lack circular arc noise reduction channels, guide channels, and arc channels, the inlet pressure of this invention can be increased by more than two times.

Claims

1. A coaxial, same-side series-connected double-impeller centrifugal fan, comprising an input shaft, an inlet channel, a first-stage impeller casing, a first-stage booster impeller, and an outlet channel, characterized in that: It also includes a secondary impeller housing and a secondary booster impeller; both the primary and secondary impeller housings are fixed on a support, the inlet channel is fixed to the primary impeller housing, and the outlet channel is fixed to the secondary impeller housing; the fluid outlet of the inlet channel is connected to the fluid inlet of the primary impeller housing, the fluid outlet of the primary impeller housing is connected to the fluid inlet of the secondary impeller housing, and the fluid outlet of the secondary impeller housing is connected to the fluid inlet of the outlet channel; the input shaft passes through the central holes of the inlet channel, the primary impeller housing, and the secondary impeller housing, and both ends of the input shaft are supported on a bearing seat by bearings; the bearing seat is fixed on the support; the primary booster impeller is placed inside the primary impeller housing, the secondary booster impeller is placed inside the secondary impeller housing, and both the primary and secondary booster impellers are fixed on the input shaft; A baffle plate is fixed inside the first-stage impeller housing, and the baffle plate is closer to the second-stage impeller housing than the first-stage booster impeller. Multiple arc-shaped guide plates are fixed on the side of the baffle plate opposite the fluid outlet of the first-stage impeller housing, and an arc-shaped flow channel is formed between adjacent arc-shaped guide plates. A circular arc noise reduction flow channel is formed between the baffle plate, the integrally formed volute tongue inside the first-stage impeller housing, each arc-shaped guide plate, and the arc-shaped inner wall of the first-stage impeller housing. The volute tongue has a flow guide channel, and one end of the circular arc noise reduction flow channel is connected to the fluid inlet of the flow guide channel. The fluid outlet of the flow guide channel is connected to the fluid outlet of the first-stage impeller housing through an arc-shaped flow channel, and the side of the circular arc noise reduction flow channel is connected to the fluid outlet of the first-stage impeller housing through the other arc-shaped flow channels. The input shaft is hollow, and a spline sleeve is fitted at the input end of the central hole of the input shaft. The outer ring of the spline sleeve has n arc-shaped grooves I evenly distributed in the circumferential direction, and the input end of the central hole of the input shaft has n arc-shaped grooves II, n≥4. Each arc-shaped groove I and an arc-shaped groove II corresponding to the circumferential position are fastened by a nylon shaft.

2. The coaxial, same-side, series-connected double-impeller centrifugal fan according to claim 1, characterized in that: Sealing gaskets are provided between the fluid outlet of the inlet channel and the fluid inlet of the first-stage impeller casing, between the fluid outlet of the first-stage impeller casing and the fluid inlet of the second-stage impeller casing, and between the fluid outlet of the second-stage impeller casing and the fluid inlet of the outlet channel.

3. The fluid pressurization and conveying method of the coaxial, same-side series-connected double-impeller centrifugal fan according to claim 1 or 2, characterized in that: The method is as follows: After the motor's output shaft is connected to the spline sleeve, the motor is started, driving the spline sleeve and input shaft to rotate. The input shaft then drives the first-stage and second-stage booster impellers to rotate. The first-stage booster impeller draws fluid from the inlet channel into the first-stage impeller housing and performs first-stage boosting on the fluid. The fluid after first-stage boosting is sent to the arc-shaped noise reduction channel. The arc-shaped noise reduction channel reduces the noise and energy loss caused by the impact between the first-stage booster fluid and the inner wall of the arc surface of the first-stage impeller housing, thereby increasing the delivery pressure. Most of the fluid in the arc-shaped noise reduction channel enters the guide channel of the volute tongue with the rotation of the first-stage booster impeller, and then enters the arc-shaped channel directly connected to the guide channel. A small portion directly enters the other arc-shaped channels. The fluid in each arc-shaped channel finally converges at the fluid outlet of the first-stage impeller housing. The second-stage booster impeller draws the fluid from the fluid outlet of the first-stage impeller housing into the second-stage impeller housing and performs second-stage boosting. The fluid after second-stage boosting is then sent to the outlet channel for output.

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