Noise reduction type centrifugal fan

Abstract

The utility model discloses a noise reduction type centrifugal fan which comprises a centrifugal fan body installed on a support body, a noise reduction pipe is connected to an air outlet of the centrifugal fan body, and an outlet pipe is connected to the tail end of the noise reduction pipe. The noise reduction pipe comprises a main pipe arranged in the middle and connecting pipes arranged at the two ends, the inner diameter of the main pipe is larger than that of the connecting pipes, the main pipe is connected with the connecting pipes at the two ends through outer conical pipes, a central pipe is coaxially arranged in the main pipe, and the inner diameter of the central pipe is smaller than that of the connecting pipes. The center pipe is connected with an outer port of the outer conical pipe through an inner conical pipe, a cavity is formed between the inner conical pipe and the main pipe, and a plurality of air holes communicated with the cavity are formed in the side wall of the inner conical pipe at equal intervals. According to the noise reduction type centrifugal fan, noise reduction can be conducted on outlet air of the centrifugal fan body, and stability is high.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal fans, specifically to a noise-reducing centrifugal fan. Background Technology

[0002] Centrifugal fans operate on the principle of converting kinetic energy into potential energy. During operation, the electric motor drives the fan blades to rotate, and air flows radially under the pressure of the blades. Accelerated by the blades, the air pressure increases and is eventually discharged through the fan outlet, forming the desired airflow. Centrifugal fans generate some noise at their outlet during operation, which needs to be reduced.

[0003] Publication number CN210343769U discloses a centrifugal fan noise reduction structure, specifically a centrifugal fan noise reduction structure, including a base, a first support column, a second support column, a vertical plate, a motor mounting plate, a motor, an arc-shaped support plate, a centrifugal fan, and a noise reduction duct. The noise reduction duct includes a straight pipe and a bent pipe, with the bent pipe fixedly connected to the bottom of the straight pipe. A first shock-absorbing pad is provided inside the motor mounting plate, and a second shock-absorbing pad is provided on the upper surface of the arc-shaped support plate.

[0004] The noise reduction structure of this centrifugal fan uses straight pipes and bends to reduce noise. However, since the bends are only located on the bottom side, the air will generate a certain impact force in the bends during the operation of the centrifugal fan. This impact force will cause the noise reduction duct to be in an unbalanced state, resulting in excessive vibration and poor noise reduction effect. Utility Model Content

[0005] The purpose of this invention is to provide a noise-reducing centrifugal fan that can reduce the noise of the airflow from the main body of the centrifugal fan and has high stability.

[0006] To achieve the above objectives, this utility model provides a noise-reducing centrifugal fan, including a centrifugal fan body mounted on a support frame. A noise-reducing pipe is connected to the air outlet of the centrifugal fan body, and an outlet pipe is connected to the end of the noise-reducing pipe. The noise-reducing pipe includes a main pipe located in the middle and connecting pipes located at both ends. The inner diameter of the main pipe is larger than the inner diameter of the connecting pipes. The main pipe and the connecting pipes at both ends are connected by outer conical pipes. A central pipe is coaxially arranged inside the main pipe. The inner diameter of the central pipe is smaller than the inner diameter of the connecting pipes. The central pipe and the outer port of the outer conical pipe are connected by an inner conical pipe. A cavity is formed between the inner conical pipe and the main pipe. Multiple air holes communicating with the cavity are evenly spaced on the side wall of the inner conical pipe.

[0007] Preferably, air ducts are provided one-to-one between the air holes of the inner conical tubes at both ends, with the middle part of the air duct extending axially and the two ends extending obliquely toward the corresponding air holes.

[0008] Preferably, the angle between the two ends of the air duct and the axis of the central duct is 10-45°.

[0009] Preferably, the air vent is coaxially arranged with both ends of the air duct.

[0010] Preferably, the two ends of the air duct are connected to the middle part of the air duct by rounded corners.

[0011] Preferably, the cavity is filled with a sound-insulating filler.

[0012] Preferably, the outer end of the outlet pipe is provided with a flange plate that connects with the air outlet.

[0013] According to the above technical solution, this utility model provides a noise-reducing centrifugal fan, including a centrifugal fan body mounted on a support body. A noise-reducing pipe is connected to the air outlet of the centrifugal fan body, and an outlet pipe is connected to the end of the noise-reducing pipe. The noise-reducing pipe includes a main pipe in the middle and connecting pipes at both ends. The inner diameter of the main pipe is larger than the inner diameter of the connecting pipes. The main pipe and the connecting pipes at both ends are connected by an outer conical pipe. A central pipe is coaxially arranged inside the main pipe. The inner diameter of the central pipe is smaller than the inner diameter of the connecting pipes. The central pipe and the outer port of the outer conical pipe are connected by an inner conical pipe. A cavity is formed between the inner conical pipe and the main pipe. Multiple air holes communicating with the cavity are evenly spaced on the side wall of the inner conical pipe.

[0014] The usage and beneficial effects of this noise-reducing centrifugal fan are as follows: During operation, the air from the main body of the centrifugal fan enters the connecting pipe at one end after passing through the outlet, and then enters the main pipe. The air entering the main pipe is divided into two paths: one path passes through the central pipe, and the other path is distributed into the cavity through multiple air holes. The air passing through the central pipe directly enters the connecting pipe at the other end, while the air in the cavity is discharged through multiple air holes at the other end, contacting the air in the central pipe. The two air paths intersect and interfere with each other, thereby achieving the purpose of noise reduction. The advantages of this noise-reducing centrifugal fan are: 1. The double-layer structure formed by the main pipe and central pipe can increase the sound insulation and noise reduction effect; 2. The multiple equally spaced air holes can maintain a relatively balanced state of air intake and exhaust, preventing additional vibration of the noise-reducing pipe, thus achieving a better noise reduction effect; 3. The intake air is divided into one main air path and multiple auxiliary air paths, and the interference between the main air path and the multiple auxiliary air paths achieves the purpose of noise reduction.

[0015] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the following detailed description to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0017] Figure 1 This is a schematic diagram of the overall structure of a preferred embodiment of a noise-reducing centrifugal fan;

[0018] Figure 2 This is a schematic diagram of the overall structure of a preferred embodiment of a noise reduction tube;

[0019] Figure 3 This is a side view of a preferred embodiment of the noise reduction tube;

[0020] Figure 4 yes Figure 3 A schematic diagram of the AA cross-sectional structure;

[0021] Figure 5 yes Figure 4 A schematic diagram of the BB cross-sectional structure.

[0022] Explanation of reference numerals in the attached figures

[0023] 1-Support body; 2-Centrifugal fan body; 3-Air outlet; 4-Noise reduction pipe; 5-Outlet pipe; 401-Main pipe; 402-Outer conical pipe; 403-Connecting pipe; 404-Flange plate; 405-Inner conical pipe; 406-Air hole; 407-Cavity; 408-Air duct; 409-Center pipe. Detailed Implementation

[0024] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0025] In this utility model, unless otherwise stated, directional terms such as "up, down, left, right, front, back, inside, outside" in the terminology only represent the orientation of the term in its conventional use or are common terms understood by those skilled in the art, and should not be regarded as a limitation on the term.

[0026] See Figure 1-5The noise-reducing centrifugal fan shown includes a centrifugal fan body 2 mounted on a support 1. A noise-reducing pipe 4 is connected to the air outlet 3 of the centrifugal fan body 2, and an outlet pipe 5 is connected to the end of the noise-reducing pipe 4. The noise-reducing pipe 4 includes a main pipe 401 located in the middle and connecting pipes 403 located at both ends. The inner diameter of the main pipe 401 is larger than the inner diameter of the connecting pipes 403. The main pipe 401 and the connecting pipes 403 at both ends are connected by an outer conical pipe 402. A central pipe 409 is coaxially arranged inside the main pipe 401. The inner diameter of the central pipe 409 is smaller than the inner diameter of the connecting pipes 403. The central pipe 409 and the outer port of the outer conical pipe 402 are connected by an inner conical pipe 405. A cavity 407 is formed between the inner conical pipe 405 and the main pipe 401. A plurality of air holes 406 communicating with the cavity 407 are evenly spaced on the side wall of the inner conical pipe 405.

[0027] Through the implementation of the above technical solution, during use, the air from the centrifugal fan body 2 enters the connecting pipe 403 at one end after passing through the air outlet 3, and then enters the main pipe 401. The air entering the main pipe 401 is divided into two paths: one path passes through the central pipe 409, and the other path is distributed to the cavity 407 through multiple air holes 406. The air passing through the central pipe 409 directly enters the connecting pipe 403 at the other end, while the air in the cavity 407 is discharged through multiple air holes 406 at the other end and comes into contact with the air in the central pipe 409. The two paths of air intersect and interfere with each other, thereby achieving the purpose of noise reduction. The advantages of this noise-reducing centrifugal fan are: 1. The double-layer structure formed by the main pipe 401 and the central pipe 409 can increase the sound insulation and noise reduction effect; 2. The multiple equally spaced air holes 406 can keep the air intake and exhaust in a relatively balanced state, without causing additional vibration of the noise-reducing pipe 4, thus achieving a better noise reduction effect; 3. The air intake is divided into one main air and multiple auxiliary air, and the noise reduction purpose is achieved through the mutual interference between the main air and the multiple auxiliary air.

[0028] In this embodiment, air ducts 408 are provided one-to-one between the air holes 406 of the inner conical tubes 405 at both ends. The air ducts 408 extend axially in the middle and extend obliquely towards the corresponding air holes 406 at both ends. The arrangement of the air ducts 408 ensures that the secondary air entering from one air hole 406 can be stably guided to the air hole 406 at the other end for discharge, thereby increasing the stability of the secondary air guidance.

[0029] In this embodiment, the angle between the two ends of the duct 408 and the axis of the central duct 409 is 10-45°. This arrangement allows the air intake of the duct 408 to be deflected outwards and the air outlet to be deflected inwards. The angle of deflection can be set to 10-45° as needed.

[0030] In this embodiment, the air vent 406 and the two ends of the air duct 408 are coaxially arranged. This arrangement allows for a smooth transition between the air vent 406 and the air duct 408. Furthermore, since a blocking slope is formed between the inner tapered tube 405 and the air inlet, the air inlet can better enter the air vent 406.

[0031] In this embodiment, the two ends of the air duct 408 are connected to the middle part of the air duct 408 with rounded corners. That is, the connection adopts a bent pipe structure, which makes the air flow more smoothly in the air duct 408 and prevents the secondary air from generating excessive sound wave fluctuations in the air duct 408.

[0032] In this embodiment, the cavity 407 is filled with a sound-insulating filler. The sound-insulating filler improves the sound insulation effect of the cavity 407, further enhancing the noise reduction effect. The sound-insulating filler can be materials such as rock wool, glass wool, polyester fiber, polyurethane, and sandstone.

[0033] In this embodiment, the outer end of the outlet pipe 5 is provided with a flange plate 404 that mates with the air outlet 3. The flange plate 404 is connected to the air outlet 3 of the centrifugal fan body 2 by multiple bolts.

[0034] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0035] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.

[0036] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.

Claims

1. A noise-reducing centrifugal fan, characterized in that, The noise-reducing centrifugal fan includes a centrifugal fan body (2) mounted on a support (1). A noise-reducing pipe (4) is connected to the air outlet (3) of the centrifugal fan body (2), and an outlet pipe (5) is connected to the end of the noise-reducing pipe (4). The noise-reducing pipe (4) includes a main pipe (401) in the middle and connecting pipes (403) at both ends. The inner diameter of the main pipe (401) is larger than the inner diameter of the connecting pipes (403). The main pipe (401) and the connecting pipes (403) at both ends are connected by an outer cone. The main tube (401) is connected to the outer conical tube (402), and a central tube (409) is coaxially arranged inside the main tube (401). The inner diameter of the central tube (409) is smaller than the inner diameter of the connecting tube (403). The central tube (409) and the outer port of the outer conical tube (402) are connected by an inner conical tube (405). A cavity (407) is formed between the inner conical tube (405) and the main tube (401). A plurality of air holes (406) communicating with the cavity (407) are equally spaced on the side wall of the inner conical tube (405).

2. The noise-reducing centrifugal fan according to claim 1, characterized in that, Air ducts (408) are provided one-to-one between the air holes (406) of the inner conical tubes (405) located at both ends; The duct (408) extends axially in the middle and extends obliquely at both ends toward the corresponding air holes (406).

3. The noise-reducing centrifugal fan according to claim 2, characterized in that, The angle between the two ends of the air duct (408) and the axis of the central duct (409) is 10-45°.

4. The noise-reducing centrifugal fan according to claim 3, characterized in that, The air vent (406) is coaxially arranged with both ends of the air duct (408).

5. The noise-reducing centrifugal fan according to claim 4, characterized in that, The two ends of the air duct (408) are connected to the middle part of the air duct (408) by rounded corners.

6. The noise-reducing centrifugal fan according to claim 1, characterized in that, The cavity (407) is filled with sound-insulating filler.

7. The noise-reducing centrifugal fan according to claim 1, characterized in that, The outer end of the outlet pipe (5) is provided with a flange plate (404) that connects with the air outlet (3).

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