Silencing and filtering box body structure of fan and working method of silencing and filtering box body structure

Abstract

The invention discloses a silencing and filtering box body structure of a fan and a working method of the silencing and filtering box body structure, and relates to the technical field of fan equipment, and the box body structure comprises an air inlet cabin body, a working cabin body and an air outlet cabin body which are arranged from top to bottom. A labyrinth type air inlet channel and a filtering unit are sequentially arranged in the air inlet cabin body in the air flow direction. An elastic membrane of the device divides a driving cavity into two chambers which are respectively communicated with a pressure pulsation source and a first filtering cavity, and the elastic membrane can directly act on an elastic core material of a first-stage filtering module through a top opening. When the system runs, the diaphragm can be driven to move periodically by utilizing pressure pulsation of the system or external pressure pulsation, so that the filter element is automatically cleaned. The noise reduction, filtering and self-cleaning functions are highly integrated, the structure is compact, noise can be effectively reduced, vibration can be effectively isolated, the maintenance frequency is remarkably reduced through self-adaptive cleaning, and the fan operation energy efficiency and reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of fan equipment technology, and in particular to a sound-absorbing filter box structure for a fan and its working method. Background Technology

[0002] Fans are crucial gas conveying equipment in modern industry. During operation, the high-speed rotating impeller interacts violently with the airflow, generating broadband aerodynamic noise at the air inlet, significantly impacting the production environment and occupational health. To control noise pollution, external intake silencers are commonly used in the industry. These traditional silencers are typically independent cylindrical units, relying on resistive silencing principles using sound-absorbing materials, and rigidly connected to the fan main unit via flanges. This structure reveals significant drawbacks in practical applications: First, its independent external design occupies extra space, resulting in a loose and poorly integrated intake system layout; second, the rigid connection becomes a direct transmission path for mechanical vibration and thermal stress, potentially leading to structural fatigue and leakage risks over long-term operation; third, its straight-through, short-channel design has limited effectiveness in reducing low-frequency noise, resulting in an overall less than ideal noise reduction spectrum.

[0003] Meanwhile, to prevent dust, fibers, and other particulate matter from entering the fan cavity and causing abnormal wear, a filtration device must be installed at the air inlet. The primary filter element, which bears the main filtration load, accumulates particulate matter extremely quickly on its surface because it is in direct contact with untreated air. This rapid accumulation causes a sharp increase in filter resistance in a short period, leading to fan performance degradation and increased energy consumption. Users are forced to schedule frequent shutdowns for maintenance, cleaning the dust through disassembly, manual tapping, or washing, or even replacing the filter element directly. This process not only increases the manpower and material costs of maintenance but, more importantly, disrupts production continuity, severely impacting the overall availability and operational economy of the equipment.

[0004] In summary, existing technical solutions often adopt a modular approach of simple, independent stacking when addressing the two core requirements of noise control and filtration maintenance in wind turbine intake systems. This results in redundant systems, limited efficiency, and inconvenient maintenance. Therefore, the industry urgently needs an innovative, integrated solution that can deeply and compactly integrate high-efficiency noise reduction and long-term filtration capabilities in its structure, and effectively reduce the frequency and difficulty of daily maintenance. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a noise reduction and filter housing structure for a fan and its working method. Through integrated structural innovation and ingenious design of energy recycling within the system, it successfully integrates multiple functions such as high-efficiency noise reduction, long-lasting self-cleaning filtration, vibration isolation, and convenient maintenance, and systematically solves the related technical problems of loose air intake structure, frequent maintenance, and poor noise control in traditional fans.

[0006] Technical solution:

[0007] A noise-reducing filter housing structure for a fan includes a housing. From top to bottom, the housing comprises an air inlet chamber, a working chamber, and an air outlet chamber. The air inlet chamber has a labyrinthine air inlet channel and a filter unit arranged sequentially along the airflow direction. The labyrinthine air inlet channel and the filter unit are integrated into a fixed mounting cavity. The air outlet chamber includes an air outlet pipe. The filter unit includes a first filter chamber, a second filter chamber, a primary filter module, a secondary filter module, and a diaphragm drive device. The filter unit has an air inlet port, an air outlet port, a drive port, and a maintenance port. The second filter chamber is located at the rear end of the first filter chamber. The primary filter module is installed within the first filter chamber, and the secondary filter module is installed within the first filter chamber. Within the second filter chamber, the primary filter module includes a frame and a primary elastic core material disposed within the frame, with an opening at the top of the frame; the diaphragm driving device includes a driving chamber, an elastic diaphragm, and a pressure guiding tube, the driving chamber being connected to the first filter chamber via the driving port, the outer edge of the elastic diaphragm being sealed and fixed within the driving chamber, the elastic diaphragm dividing the driving chamber into a pressure chamber and a pushing chamber, the working part of the elastic diaphragm being configured to align with the opening at the top of the frame, one end of the pressure guiding tube being connected to a pressure pulsation source, and the other end of the pressure guiding tube being connected to the pressure chamber; the air outlet of the filter unit is connected to the air inlet of the blower unit located within the working chamber.

[0008] Furthermore, the primary filtration module also includes a rigid pressure equalizing plate slidably disposed on the upper end of the frame, and the rigid pressure equalizing plate is provided with an air guide groove for maintaining air pressure communication between the upper and lower sides of the rigid pressure equalizing plate.

[0009] Furthermore, the pressure pulsation source is the air outlet pipe, and the pressure guiding pipe is connected to the air outlet pipe.

[0010] Furthermore, the pressure pulsation source is an external pulsation generator.

[0011] Furthermore, the bottom of the frame is provided with a collection groove, the upper cross section of which is a trapezoidal structure that is wider at the top and narrower at the bottom, and the bottom shape of the primary elastic core material is set to correspond to the upper structure of the collection groove.

[0012] Furthermore, the elastic diaphragm is made of rubber or silicone.

[0013] Furthermore, the primary elastic core material is made of polyurethane foam.

[0014] Furthermore, the labyrinthine air intake channel is composed of multi-stage baffles, and the walls of the baffles are provided with sound-absorbing material.

[0015] This invention also discloses a method for operating a noise-reducing filter housing structure for a fan, comprising the following steps:

[0016] S1. Under the negative pressure of the main fan, the outside air enters the filter unit after being silenced by the labyrinth-type air intake channel of the air intake chamber;

[0017] S2. Air first passes through the primary filtration module, where the primary elastic core material intercepts most of the particulate matter. At the same time, the periodic pressure fluctuations generated by the pressure pulsation source are transmitted to the air pressure chamber of the diaphragm drive device through the pressure guide tube, driving the elastic diaphragm to reciprocate.

[0018] S3. The movement of the elastic diaphragm acts on the primary elastic core material through the opening at the top of the frame, causing it to deform periodically and shake off the attached particles into the collection tank at the bottom.

[0019] S4. The air that has been cleaned and filtered by the first-stage filtration module continues to be finely filtered by the second-stage filtration module.

[0020] S5. Finally, clean air is delivered to the air inlet of the fan unit through the air outlet of the filter unit.

[0021] Furthermore, the pressure pulsation source is the exhaust pipe. When the ambient temperature rises, the operating conditions of the main fan change accordingly, resulting in an increase in the amplitude of the exhaust pressure pulsation in the exhaust pipe. The increased exhaust pressure pulsation is transmitted to the diaphragm drive device through the pressure guide pipe, driving the elastic diaphragm to vibrate periodically with a larger amplitude of motion, thereby enabling the system to automatically enhance its cleaning ability for the primary elastic core material under high temperature conditions.

[0022] Beneficial effects:

[0023] 1. The labyrinthine air intake channel and filter unit are integrated from top to bottom into a unified housing. This integrated cabin design greatly improves space utilization, making the overall structure more compact and regular, facilitating modular layout and installation of the equipment, and is particularly suitable for applications with strict space requirements.

[0024] 2. The enclosure integrates the intake silencer and filter with the main fan compartment in a structurally unified design while also functionally dividing the space. This effectively attenuates and isolates the mechanical vibrations generated during the main fan's operation from being transmitted to the intake silencer. This fundamentally solves the vibration transmission and thermal stress problems caused by rigid connections in traditional external silencers, significantly improving the system's structural integrity and long-term operational reliability.

[0025] 3. Through a unique membrane drive device, the system cleverly utilizes its own pressure pulses as a power source to automatically and continuously clean the primary elastic filter element periodically, thereby greatly slowing down the rate of resistance increase caused by particulate matter adhesion. This means that the cycle of manual cleaning or filter element replacement can be significantly extended.

[0026] 4. Because the primary filter module has self-cleaning capabilities, its average operating resistance is maintained at a low level. This directly reduces the intake pressure loss of the fan, helping to save operating energy. At the same time, stable and unobstructed air intake ensures that the fan unit can continuously operate in the high-efficiency range with stable output flow, thereby improving the long-term operating energy efficiency and economy of the entire fan system. Attached Figure Description

[0027] Figure 1 This is an external perspective view of the housing of the present invention;

[0028] Figure 2 This is a three-dimensional view of the interior of the housing of the present invention;

[0029] Figure 3 This is a perspective view of the external structure of the labyrinth-type air intake channel and filter unit of the present invention;

[0030] Figure 4 This is a three-dimensional view of the internal structure of the labyrinth-type air intake channel and filter unit of the present invention.

[0031] Figure 5 This is a schematic diagram of the structure of the primary filtration module and the membrane drive device of the present invention;

[0032] Figure 6 This is a schematic diagram of the internal structure of the primary filtration module of the present invention;

[0033] Figure 7 This is a cross-sectional structural diagram of the primary filtration module and membrane drive device of the present invention;

[0034] Figure 8 This is the installation cross-section of the housing and the fan of the present invention. Figure 1 ;

[0035] Figure 9 This is the installation cross-section of the housing and the fan of the present invention. Figure 2 . Detailed Implementation

[0036] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Example 1

[0038] like Figure 1-9As shown, a noise-reducing filter housing structure for a fan includes a housing 1, which comprises, from top to bottom, an air inlet chamber 2, a working chamber 3, and an air outlet chamber 4. This vertically layered chamber layout allows external airflow to pass through the housing 1 in a natural flow sequence of intake, working, and exhaust, resulting in a compact structure that conforms to aerodynamic principles. The air inlet chamber 2 is sequentially equipped with a labyrinthine intake channel 21 and a filter unit 22 along the airflow direction. The labyrinthine intake channel 21 and the filter unit 22 are integrated into a fixed mounting cavity. This integrated design achieves a tight connection between noise reduction and filtration functions, allowing the airflow to smoothly enter the next stage after initial purification. The air outlet chamber 4 includes an outlet pipe for connecting to downstream equipment or a pipeline network. The filter unit 22 includes a first filter chamber 221, a second filter chamber 222, a primary filter module 223, a secondary filter module 224, and a membrane drive device 225. This combination of multiple chambers and modules constitutes the core of graded filtration and self-cleaning. The filter unit 22 has an air inlet port, an air outlet port, a drive port, and a maintenance port. The multiple ports meet different needs for airflow, pressure signal transmission, and daily maintenance. The second filter chamber 222 is located at the rear end of the first filter chamber 221, ensuring that air must pass through the primary filter module 223 before reaching the secondary filter module 224. The primary filter module 223 is installed inside the first filter chamber 221, serving as the primary barrier of the filtration system. The secondary filter module 224 is installed inside the second filter chamber 222, performing deep filtration on the air that has passed through the primary filter. The primary filter module 223 includes a frame 2231 and a primary elastic core material 2232 disposed within the frame 2231. The frame 2231 provides a stable mounting framework for the elastic filter medium. The top of the frame 2231 has an opening, which is a key interface for transmitting cleaning power. The diaphragm drive device 225 includes a drive chamber 2251, an elastic diaphragm 2252, and a pressure guide tube 2253. The drive chamber 2251 is connected to the first filter chamber 221 through the drive port, so that the pressure in the push chamber of the drive chamber 2251 is equal to the air inlet pressure in front of the filter element in real time. The outer edge of the elastic diaphragm 2252 is sealed and fixed in the drive chamber 2251, serving as an actuator that converts pressure energy into mechanical action. The elastic diaphragm 2252 divides the drive chamber 2251 into a pressure chamber and a push chamber, thereby structurally isolating the drive pressure source from the filter chamber. The working part of the elastic diaphragm 2252 is configured to align with the opening at the top of the frame 2231, ensuring that its reciprocating motion can act directly on the upper surface of a single piece of primary elastic core material 2232 without obstruction. One end of the pressure guide tube 2253 is connected to the pressure pulsation source, and the other end of the pressure guide tube 2253 is connected to the pressure chamber; the air outlet of the filter unit 22 is connected to the air inlet of the fan host located in the working chamber 3, thereby delivering the finally filtered clean air to the fan.

[0039] As a gas conveying device, the basic working principle of the fan determines that the inlet of the main unit forms a negative pressure state lower than the external atmospheric pressure due to the suction effect, while the outlet of the main unit forms a positive pressure state higher than the atmospheric pressure due to the compression of the gas. This stable situation where the outlet pressure is higher than the inlet pressure, generated by the working characteristics of the main unit, constitutes the basic pressure difference environment of the drive system. The primary filter module 223 also includes a rigid pressure equalizing plate 2233 slidably mounted on the upper end of the frame 2231. The rigid pressure equalizing plate 2233 is provided with air guide grooves 2234 to keep the space on the upper and lower sides of the rigid pressure equalizing plate 2233 connected by air pressure. The core function of the rigid pressure equalizing plate 2233 is that when the elastic diaphragm 2252 is pushed downward, it can evenly distribute the concentrated force of a point or surface to the entire top surface area of ​​the primary elastic core material 2232, avoiding premature fatigue damage to the filter element due to excessive local stress; the air guide grooves 2234 opened on its surface ensure that the air above and below the plate can circulate freely when the pressure equalizing plate 2233 slides up and down, preventing the formation of a closed air cushion, thereby eliminating unnecessary motion damping and making the cleaning action smoother and more efficient.

[0040] Optionally, the pressure pulsation source is the exhaust pipe, and the pressure guiding pipe is connected to the exhaust pipe. The principle of this connection method is to directly utilize the inherent pressure pulsation component in the exhaust airflow of the blower main unit, generated by the periodic movement of the rotor (such as screw meshing or impeller rotation), as a free and synchronous energy source for driving the diaphragm drive device 225, thereby realizing the recovery and reuse of energy within the system.

[0041] Optionally, the pressure pulsation source is an external pulsation generator. This configuration provides additional flexibility and control precision, allowing users to set the frequency, amplitude, and even waveform of cleaning actions completely independently of the host's operating conditions to adapt to particularly harsh dust conditions or special maintenance cycle requirements.

[0042] The bottom of the frame 2231 is provided with a collection groove 2235. The upper cross-section of the collection groove 2235 is a trapezoidal structure that is wider at the top and narrower at the bottom. The bottom shape of the primary elastic core material 2232 corresponds to the upper structure of the collection groove 2235. The trapezoidal collection groove 2235 forms a funnel-shaped flow guiding structure. Particles shaken off by the periodic cleaning action can smoothly slide into the narrow bottom of the collection groove 2235 under the action of gravity along the inclined surface of the bottom of the filter element. This effectively prevents dust from accumulating at the right-angle joint between the filter element and the frame 2231, facilitating subsequent centralized cleaning through the maintenance port and keeping the system clean.

[0043] The elastic diaphragm 2252 is made of rubber or silicone. These materials are chosen because of their excellent elasticity, superior fatigue resistance, and reliable sealing performance, ensuring continued operational efficiency and service life even under prolonged cyclic pressure fluctuations and deformation. The tensile strength of this type of elastic diaphragm is ≥10 MPa, while the maximum actual pressure difference (steady-state + pulsating) does not exceed 120 kPa. The maximum stress generated by this pressure difference on an effective diaphragm area (approximately 0.011 m²) with a diameter of, for example, 120 mm, is only 0.33 MPa, less than 3% of the material's ultimate strength, providing a safety factor exceeding 30 times. Furthermore, the diaphragm can employ a sandwich reinforcement structure (intermediate fabric reinforcement layer), capable of withstanding over 500,000 cycles of reciprocating bending without fatigue cracking, fully meeting the design life requirement of over 5 years.

[0044] The primary elastic core material 2232 is made of polyurethane foam. Open-cell polyurethane foam possesses a three-dimensional interconnected porous structure, which provides a large surface area for intercepting and containing particulate matter. Simultaneously, the material's inherent elasticity allows it to withstand repeated compression and recovery under membrane-driven conditions without permanent structural collapse, thus maintaining long-lasting filtration and self-cleaning performance.

[0045] Furthermore, a miniature pneumatic relay cavity can be added in the middle section of the pressure-conducting pipeline. This relay cavity can compensate for the capacitive hysteresis effect of the long pipeline, so that the end response delay is still controlled within 0.1 seconds and the pulsation amplitude loss does not exceed 15%, thereby ensuring that the cleaning efficiency is not significantly affected.

[0046] The labyrinthine air intake channel 21 is composed of multi-stage baffles, with sound-absorbing material applied to the walls of the baffles. Its noise reduction mechanism combines reactive and resistive noise reduction principles. The multi-stage baffles force the airflow to change direction and pass through abrupt changes in cross-section multiple times, thereby causing reflection, interference, and expansion attenuation of sound waves, especially targeting low-frequency noise. The sound-absorbing material applied to the baffle walls converts mid-to-high frequency sound energy into heat energy through friction and viscosity, thus achieving wideband and efficient suppression of the entire intake noise spectrum.

[0047] Example 2

[0048] This invention also discloses a method for operating a noise-reducing filter housing structure for a fan, comprising the following steps:

[0049] S1. Under the negative pressure of the fan host, the outside air enters the filter unit 22 after being silenced by the labyrinth-type air intake channel 21 of the air intake chamber 2. The labyrinth-type air intake channel 21 first guides and rectifies the incoming airflow, and uses its complex path and sound-absorbing structure to significantly reduce the mid-to-high frequency noise energy carried by the airflow, creating a more stable airflow environment for subsequent filtration.

[0050] S2. Air first passes through the primary filtration module 223, where the primary elastic core material 2232 intercepts most particulate matter. Simultaneously, periodic pressure fluctuations generated by the pressure pulsation source are transmitted through the pressure guide tube 2253 to the air pressure chamber of the diaphragm drive device 225, driving the elastic diaphragm 2252 to reciprocate. The optimized design of the pressure guide tube 2253 ensures the real-time performance and fidelity of the pressure pulsation signal transmission.

[0051] S3. The movement of the elastic diaphragm 2252, through the opening at the top of the frame 2231, acts on the primary elastic core material 2232, causing it to undergo periodic deformation, shaking off the attached particles into the collection trough 2234 at the bottom. This deformation mechanically disturbs the filter media fibers and their attachments, causing loosely adhered particles to detach and fall into the collection trough 2234 at the bottom under gravity. The driving force generated by the elastic diaphragm 2252, after transmission and pressure equalization, is fully capable of overcoming the elastic resistance of the filter element, achieving effective cleaning deformation.

[0052] S4. After being cleaned and filtered by the primary filtration module 223, the air continues to be finely filtered by the secondary filtration module 224. The secondary filtration module 224 typically uses higher precision filter media to capture residual fine particles and ensure that the final air cleanliness meets the intake requirements of the fan unit.

[0053] S5. Finally, clean air is delivered to the air inlet of the main fan unit through the outlet port of the filter unit 22. This provides a continuous and clean air source for the main fan, effectively protecting the precision components such as the impeller and rotor inside the main fan unit from wear.

[0054] Furthermore, the pressure pulsation source is the exhaust pipe. When the ambient temperature rises, the operating conditions of the main fan change accordingly, resulting in an increase in the amplitude of the exhaust pressure pulsation in the exhaust pipe. The increased exhaust pressure pulsation is transmitted to the diaphragm drive device 225 through the pressure guide pipe 2253, driving the elastic diaphragm 2252 to vibrate periodically with a larger amplitude of motion, thereby enabling the system to automatically enhance its cleaning ability for the primary elastic core material 2232 under high temperature conditions.

[0055] The embodiments described above are merely illustrative of certain implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A sound-absorbing filter housing structure for a fan, characterized in that, The enclosure includes a housing (1), which from top to bottom comprises an air intake chamber (2), a working chamber (3), and an air outlet chamber (4). The air intake chamber (2) is provided with a labyrinthine air intake channel (21) and a filter unit (22) in sequence along the airflow direction. The labyrinthine air intake channel (21) and the filter unit (22) are integrated into a fixed installation cavity. The air outlet chamber (4) includes an air outlet pipe. The filter unit (22) includes a first filter chamber (221), a second filter chamber (222), and a primary filter. The filter unit (22) comprises a filter module (223), a secondary filter module (224), and a membrane drive device (225). The filter unit (22) has an air inlet port, an air outlet port, a drive port, and a maintenance port. The second filter chamber (222) is located at the rear end of the first filter chamber (221). The primary filter module (223) is installed within the first filter chamber (221), and the secondary filter module (224) is installed within the second filter chamber (222). 223) includes a frame (2231) and a primary elastic core material (2232) disposed within the frame (2231), wherein the top of the frame (2231) is provided with an opening; the membrane driving device (225) includes a driving cavity (2251), an elastic membrane (2252) and a pressure guiding tube (2253), wherein the driving cavity (2251) is connected to the first filter cavity (221) through the driving port, and the outer edge of the elastic membrane (2252) is sealed and fixed to the driving cavity (2251). Inside 2251), the elastic diaphragm (2252) divides the drive chamber (2251) into a pressure chamber and a push chamber. The working part of the elastic diaphragm (2252) is set to align with the opening at the top of the frame (2231). One end of the pressure guide tube (2253) is connected to the pressure pulsation source, and the other end of the pressure guide tube (2253) is connected to the pressure chamber (2253). The air outlet of the filter unit (22) is connected to the air inlet of the fan host located in the working chamber (3).

2. The sound-absorbing filter housing structure for a fan according to claim 1, characterized in that, The primary filtration module (223) also includes a rigid pressure equalizing plate (2233) that is slidably disposed on the upper end of the frame (2231). The rigid pressure equalizing plate (2233) is provided with an air guide groove (2234) for maintaining air pressure communication between the upper and lower sides of the rigid pressure equalizing plate (2233).

3. The sound-absorbing filter housing structure for a fan according to claim 1, characterized in that, The pressure pulsation source is the air outlet pipe, and the pressure guiding pipe is connected to the air outlet pipe.

4. The sound-absorbing filter housing structure for a fan according to claim 1, characterized in that, The pressure pulsation source is an external pulsation generator.

5. The sound-absorbing filter housing structure for a fan according to claim 1, characterized in that, The bottom of the frame (2231) is provided with a collection groove (2235), the upper section of the collection groove (2235) is a trapezoidal structure that is wider at the top and narrower at the bottom, and the bottom shape of the primary elastic core material (2232) corresponds to the upper structure of the collection groove (2235).

6. The sound-absorbing filter housing structure for a fan according to claim 1, characterized in that, The elastic diaphragm (2252) is made of rubber or silicone.

7. The sound-absorbing filter housing structure for a fan according to claim 1, characterized in that, The primary elastic core material (2232) is made of polyurethane foam.

8. The sound-absorbing filter housing structure for a fan according to claim 1, characterized in that, The labyrinthine air intake channel (21) is composed of multi-stage baffles, and the walls of the baffles are provided with sound-absorbing material.

9. A method for operating the silencer filter housing structure of a fan as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Under the negative pressure of the blower host, the outside air enters the filter unit (22) after being silenced by the labyrinthine air intake channel (21) of the air intake chamber (2); S2. The air first passes through the primary filter module (223), and the primary elastic core material (2232) intercepts most of the particles; at the same time, the periodic pressure fluctuation generated by the pressure pulsation source is transmitted to the air pressure chamber of the diaphragm drive device (225) through the pressure guide pipe (2253), driving the elastic diaphragm (2252) to reciprocate; S3. The movement of the elastic diaphragm (2252) acts on the primary elastic core material (2232) through the opening at the top of the frame (2231), causing it to undergo periodic deformation, shaking off the attached particles to the collection tank (2234) at the bottom; S4. The air cleaned and filtered by the primary filter module (223) continues to be finely filtered through the secondary filter module (224); S5. Finally, the clean air is sent to the air intake end of the blower host through the air outlet of the filter unit (22).

10. The working method of the noise-reducing filter box structure for a fan according to claim 9, characterized in that, The pressure pulsation source is the exhaust pipe. When the ambient temperature rises, the operating conditions of the main fan change accordingly, resulting in an increase in the amplitude of the exhaust pressure pulsation in the exhaust pipe. The increased exhaust pressure pulsation is transmitted to the diaphragm drive device (225) through the pressure guide pipe (2253), which drives the elastic diaphragm (2252) to vibrate periodically with a larger amplitude of motion, thereby enabling the system to automatically enhance its cleaning ability on the primary elastic core material (2232) under high temperature conditions.

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