Multi-stage flow guide air purifier air duct device

Abstract

The invention provides a multi-stage flow guide air purifier air duct device, and relates to the technical field of air purifiers, the multi-stage flow guide air purifier air duct device comprises a lower shell, an upper cover is arranged on the lower shell, a filtering mechanism used for filtering air is arranged in the lower shell, a screw mechanism used for rectifying and disinfecting airflow is arranged in the filtering mechanism, a fan support is arranged in the upper cover, and a fan is arranged in the fan support. According to the invention, specifically designed rear guide pressurizing blades (the number of the blades is set to be 1.2-1.5 times of the number of the blades of the centrifugal fan, and 7, 9 or 11 odd blades can be selected) are fixedly mounted on the inner wall of the fan bracket, and the ratio of the number of the centrifugal fan to the number of the rear guide pressurizing blades is accurately determined by means of a modal analysis technology; the integral multiple of the rotating frequency of the centrifugal fan is avoided, the resonance phenomenon in the equipment operation process is effectively restrained (the amplitude is reduced by 30%), and meanwhile the curvature radius R of the windward side of the rear guide pressurizing blade is matched with the rotating direction of the centrifugal fan.

Description

Technical Field

[0001] This invention belongs to the field of air purifier technology, and more specifically, relates to a multi-stage airflow guiding air duct device for an air purifier. Background Technology

[0002] Our company's market research and product performance testing of air purifier duct devices have revealed four major technical pain points that prevalent in similar products within the industry, severely hindering user experience and overall performance. The specific issues are as follows:

[0003] Firstly, existing aromatherapy products often place the aromatherapy boxes in a low-flow area with a wind speed of ≤3m / s within the air duct. Due to insufficient airflow intensity, the evaporation rate of volatile substances in the aromatherapy blocks is generally low. This not only results in slow fragrance diffusion and uneven indoor fragrance coverage, requiring users to wait a long time to experience the aromatherapy effect, but also leads to the waste of aromatherapy substances, making it difficult to meet users' demand for "quick fragrance creation".

[0004] Secondly, most products use AC motors to drive the impeller. These motors not only have significantly higher energy consumption (more than 30% higher than high-efficiency DC motors), but also have a shorter lifespan (generally less than 15,000 hours), increasing long-term operating costs for users. At the same time, AC motors have poor output power stability, which can easily lead to insufficient air pressure when driving the impeller, making it difficult for the actual air volume of the equipment to exceed 200m³ / h, thus limiting the purification efficiency. Furthermore, the electromagnetic noise generated during operation is superimposed with mechanical noise, and the noise level at a distance of 1m is often higher than 55dB(A), making them extremely unsuitable for noise-sensitive environments (such as bedrooms and studies).

[0005] Third, although some products are equipped with rear guide blades, they are not designed from the perspective of structural compatibility: neither modal analysis is used to determine the ratio of the number of rear guide blades to the impeller blades (not following the optimal ratio of 1.2-1.5 times), nor is the gap between the air inlet of the rear guide blade and the impeller controlled (deviating from the reasonable range of 3-5mm). This makes it easy for the rear guide blades and the impeller to resonate when they are running, with a significant increase in amplitude. At the same time, it causes airflow turbulence, which not only further aggravates the noise problem, but also causes wind pressure loss of more than 10%, making it impossible to achieve effective pressurization.

[0006] Fourth, the air duct system lacks a scientific airflow guidance structure. After the air flows through the filter, it is prone to significant turbulence due to problems such as obstruction by the annular inner wall and uneven airflow from the filter element. On the one hand, this leads to an artificial increase in airflow resistance, resulting in an actual airflow volume that is 15% to 20% lower than the design value, and a significant decrease in air purification efficiency (especially in large spaces where purification time is prolonged). On the other hand, the airflow impact and friction caused by turbulence will generate additional noise, which, when superimposed with the noise of the motor and impeller, further worsens the noise level of the equipment and seriously affects the user experience.

[0007] Therefore, there is an urgent need for an innovative air duct structure that can optimize airflow path and improve wind pressure and aromatherapy efficiency. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a multi-stage air purifier duct device to solve the problem that the duct system lacks a scientific airflow guiding structure, and that significant turbulence is easily generated after air flows through the filter due to problems such as obstruction by the annular inner wall and uneven airflow from the filter element.

[0009] A multi-stage air purifier duct device includes a lower shell with an upper cover. The lower shell contains a filter mechanism for filtering air, and the filter mechanism contains a spiral mechanism for rectifying and disinfecting the airflow. The upper cover contains a fan bracket with a DC motor mounted on it. A centrifugal fan is fixedly mounted on the lower end of the DC motor via an output shaft. Rear guide pressure boosting blades are fixedly mounted on the inner wall of the fan bracket.

[0010] Preferably, the filtration mechanism includes a filter, a photocatalytic filter screen is fixedly installed on the inner wall of the filter, the filter is made of polyester fiber and ultra-fine glass fiber, and a bottom cover is provided at the lower end of the filter, the bottom cover is fixedly installed at the lower end of the lower shell by a snap fastener.

[0011] Preferably, the spiral mechanism includes two spiral blades, which are fixedly installed on the inner wall of the photocatalytic filter. Spiral grooves are formed on the upper surface of both spiral blades. Small UV-C LED beads are fixedly installed at equal intervals in the spiral grooves of the two spiral blades. A plastic porous mesh is fixedly installed between the two spiral blades.

[0012] Preferably, the fan bracket is provided with an aromatherapy module, an aromatherapy box is slidably installed in the aromatherapy module, an aromatherapy block is provided in the aromatherapy box, an air outlet grille is provided at the top of the upper cover, an operation panel is provided on the upper cover, and an air inlet grille is provided between the centrifugal fan and the filter.

[0013] Preferred,

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] In this invention, specially designed rear-guide pressurizing blades (the number of blades is set to 1.2-1.5 times the number of centrifugal fan blades, with 7, 9, or 11 odd-numbered blades optional) are fixedly installed on the inner wall of the fan bracket. Modal analysis technology is used to accurately determine the blade ratio between the centrifugal fan and the rear-guide pressurizing blades, avoiding integer multiples of the centrifugal fan's rotation frequency, effectively suppressing resonance during equipment operation (reducing amplitude by 30%). At the same time, the radius of curvature R of the windward side of the rear-guide pressurizing blades is matched with the rotation direction of the centrifugal fan. This design not only significantly suppresses airflow turbulence and reduces energy loss during airflow, but also increases the outlet air pressure by 15% to 20%, enabling the clean air velocity to reach 8 to 12 m / s and the overall air volume of the equipment to be ≥200 m³ / h. Ultimately, this achieves a highly efficient airflow pressurization effect that increases the clean air diffusion speed by 30%, significantly improving the coverage and efficiency of air purification.

[0016] In this invention, an aromatherapy module is installed on a fan bracket, and an aromatherapy box is integrated into the aromatherapy module in a sliding installation manner (for easy replacement of aromatherapy blocks). The aromatherapy box is precisely positioned on the outlet side of the centrifugal fan inside the fan bracket—this area is a high-velocity region with an air velocity of ≥5m / s within the air duct. When the device is running, the high-speed airflow directly washes over the surface of the aromatherapy box, quickly carrying away the volatile aroma substances from the aromatherapy blocks inside the box, significantly accelerating the diffusion rate of the aromatherapy substances (increasing the aroma evaporation rate by 50% compared to traditional aromatherapy installation methods). At the same time, since the aromatherapy box can be flexibly disassembled and replaced, users can replace different types of aromatherapy blocks according to different scenarios (such as sleep-aiding fragrance in the bedroom, fresh fragrance in the living room, and refreshing fragrance in the office), perfectly adapting to the fragrance needs of multiple scenarios, realizing intelligent aromatherapy release function, and improving the comfort of the indoor environment while purifying the air.

[0017] In this invention, by employing a rear-guide pressurizing blade design with an odd number of blades (7, 9, or 11 blades), and in conjunction with a DC motor that drives the centrifugal fan with low-noise operation characteristics, noise generation is controlled from both structural design and core component selection aspects: the odd number of blades in the rear-guide pressurizing blades optimizes the airflow trajectory, reduces turbulent noise generated by the impact and friction between the airflow and the blades, and avoids resonance frequencies with the centrifugal fan, thus preventing the superposition of resonance noise; and the DC motor itself has lower electromagnetic and mechanical noise than traditional AC motors. The combined effect of these two factors results in the noise level of the device at a distance of 1m being ≤50dB(A), which is 5dB(A) lower than the overall noise of traditional air purifier duct devices, achieving an ultra-quiet operation effect. Even when used in noise-sensitive scenarios such as bedrooms and studies, it will not disturb the user's rest or work.

[0018] In this invention, a DC motor is selected as the core power component to drive the centrifugal fan. Compared with the AC motor commonly used in traditional air purifiers, the DC motor has a significant advantage in terms of energy consumption—energy consumption is reduced by 30% compared with traditional motors. At the same time, combined with the overall optimized air duct design of the equipment (such as the rear guide pressure boosting blades to increase air pressure and the spiral blades to reduce turbulence loss), energy waste during airflow is reduced, enabling the equipment's comprehensive energy efficiency to reach the first-level standard, effectively reducing the long-term electricity cost of the equipment.

[0019] In this invention, two spiral blades are fixedly installed on the inner wall of the photocatalytic filter in the filtration mechanism. The spiral installation method adapts the blades to the air duct structure. When the airflow that has been initially purified by the filtration mechanism enters the interior of the photocatalytic filter, the two spiral blades can actively guide the airflow to flow upward along the spiral trajectory and gradually move towards the middle air duct. This effectively solves the turbulence phenomenon that is easily caused by the obstruction of the annular inner wall and uneven airflow of the filter element in the internal air duct of the filter. It avoids the "artificial increase in wind resistance" caused by turbulence (that is, the airflow consumes extra energy due to disordered collision, resulting in a reduction in the actual effective air volume), reduces the energy loss in the airflow process, indirectly increases the actual air volume of the equipment, and makes the airflow smoother. At the same time, it optimizes the airflow direction of the entire air duct system and lays a stable airflow foundation for the subsequent disinfection, purification and pressurization conveying links.

[0020] In this invention, spiral grooves are formed on the upper surfaces of both spiral blades, and small UV-C LED beads are fixedly installed at equal intervals within these grooves. This fully utilizes the characteristics of both blades to achieve deep complementarity: On the one hand, the small UV-C LED beads are small in size and can be directly integrated into the spiral grooves on the surface of the spiral blades, without occupying the airflow channel. They also have low energy consumption and generate little heat, so they will not change the airflow state due to high temperatures, nor will they accelerate blade aging. Their built-in circuit design can also avoid interfering with the airflow. On the other hand, the spiral blades themselves have the characteristic of guiding airflow. Combined with the plastic porous evenly distributed mesh (the mesh surface is perpendicular to the air duct and covers the entire air duct cross-section) fixedly installed between the two spiral blades, the airflow can be effectively guided. The "dispersed airflow" is transformed into "uniform airflow" and slightly obstructs the airflow, extending the residence time of the airflow in the spiral blade area. This allows the airflow to more fully contact the ultraviolet rays emitted by the UV-C LED beads. This ultraviolet light can activate the photocatalytic filter (titanium dioxide TiO2 nano-coating), enabling it to efficiently decompose bacteria, viruses, and VOCs (such as formaldehyde and benzene) in the airflow. This avoids the problem of some microorganisms not being irradiated and insufficient purification due to excessively fast airflow. At the same time, the porous plastic mesh can also block a small amount of carbon powder and fiber that falls off the filter element, protecting the subsequent centrifugal fan. Ultimately, through the complementary characteristics of both, the uniformity and efficiency of sterilization and deep purification are significantly improved, achieving a purification effect of 1+1>2. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the wind turbine support structure of the present invention;

[0023] Figure 3 This is a schematic diagram of the centrifugal fan structure of the present invention;

[0024] Figure 4 This is a schematic diagram of the lower shell structure of the present invention;

[0025] Figure 5 This is a schematic diagram of the filter structure of the present invention;

[0026] Figure 6 This is a schematic diagram of the spiral blade structure of the present invention;

[0027] Figure 7 This is a schematic diagram of the DC motor structure of the present invention;

[0028] Figure 8 This is the present invention. Figure 2 An enlarged schematic diagram of the structure at point A.

[0029] In the diagram, the correspondence between the component names and the attached drawing numbers is as follows: 1. Bottom cover; 2. Photocatalytic filter; 3. Spiral blades; 4. Spiral groove; 5. Small UV-C LED beads; 6. Plastic porous mesh; 7. Filter; 8. Lower shell; 9. Fan bracket; 10. Centrifugal fan; 11. DC motor; 12. Aromatherapy module; 13. Rear guide booster blades; 14. Top cover; 15. Air outlet grille; 16. Control panel; 17. Air inlet grille; 18. Aromatherapy box; 19. Aromatherapy block. Detailed Implementation

[0030] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0031] Please see Figure 1 - Figure 8This invention provides a multi-stage air purifier duct device, including a lower shell 8, with an upper cover 14 on the lower shell 8. The lower shell 8 contains a filter mechanism for filtering air, and the filter mechanism contains a spiral mechanism for rectifying and disinfecting the airflow. The upper cover 14 contains a fan bracket 9, on which a DC motor 11 is mounted. A centrifugal fan 10 is fixedly mounted at the lower end of the DC motor 11 via an output shaft. An odd number (7 / 9 / 11 pieces) of fan bracket 9 are fixedly mounted on the inner wall of the fan bracket 9. The number of rear guide pressure boosting blades 13 is 1.2-1.5 times the number of blades of centrifugal fan 10. The number of blades of centrifugal fan 10 and rear guide pressure boosting blades 13 is determined by modal analysis to avoid integer multiples of the rotation frequency of centrifugal fan 10 and suppress resonance (amplitude reduction of 30%). The air inlet of rear guide pressure boosting blades 13 is 3-5mm away from centrifugal fan 10 to achieve an air volume ≥200m³ / h and noise ≤50dB(A) (1m distance). The service life of DC motor 11 exceeds 20,000 hours.

[0032] The radius of curvature R of the windward surface of the rear guide pressurizing blade 13 is matched with the rotation direction of the centrifugal fan 10, satisfying the relationship: R=D / 2(1+θ / 180).

[0033] Where D is the rotor diameter and θ is the blade installation angle (20°-35°).

[0034] This allows for optimization of the air guide surface curvature, increasing the air outlet pressure by 15%–20% and achieving a wind speed of 8–12 m / s.

[0035] like Figure 4 , Figure 5 and Figure 7 As shown, the filtration mechanism includes a filter 7, on which a photocatalytic filter 2 is fixedly installed. The outermost layer of the filter 7 is made of polyester fiber, which can effectively filter hair, dander, lint, and large dust particles, protecting the subsequent filter element. The middle layer of the HEPA filter is made of ultra-fine glass fiber (diameter ≤1μm), which is bonded into a dense layer by hot melting, resulting in high filtration accuracy (H10-H14 grade, filtration efficiency for 0.3μm particles ≥99.97%). The bottom end of the filter 7 is provided with a bottom cover 1, which is fixedly installed at the bottom end of the lower shell 8 by a snap fastener.

[0036] like Figure 5 , Figure 6 and Figure 7As shown, the spiral mechanism includes two spiral blades 3, which are fixedly installed on the inner wall of the photocatalytic filter 2 via a spiral mounting method. Spiral grooves 4 are formed on the upper surface of each of the two spiral blades 3. Small UV-C LED beads 5 are equidistantly fixed within the spiral grooves 4 of the two spiral blades 3. These small UV-C LED beads 5 are small in size and can be directly integrated onto the surface of the spiral blades 3, without occupying the airflow channel. They also have low energy consumption, low heat generation, and will not change the airflow state due to high temperatures, nor will they accelerate blade aging. Their wiring is installed inside the spiral blades 3 and connected to the overall power control assembly of the device. A porous plastic mesh 6 is fixedly installed between the two spiral blades 3. The mesh surface of the porous plastic mesh 6 is perpendicular to the air duct (ring-shaped, covering the entire cross-section of the air duct), allowing the "dispersed airflow" from the inside of the filter element to pass through the mesh and become a "uniform airflow". Entering the central area, this design avoids the problem of "excessively strong local airflow and no wind in local areas." It also slightly obstructs the airflow, causing it to stop at the position of the spiral blades 3. This improves the uniformity of sterilization achieved by the small UV-C LED beads 5 inside the spiral blades 3 in conjunction with the photocatalytic filter 2 (the photocatalytic filter 2 is a titanium dioxide TiO2 nano-coating, which can decompose bacteria, viruses, and VOCs (formaldehyde, benzene) under light). It prevents some microorganisms from being unilluminated due to excessively fast airflow and also blocks a small amount of carbon powder and fiber that falls off the filter element, protecting the subsequent fan. The design of two sets of spiral blades 3 optimizes the airflow direction and reduces turbulence losses. The airflow inside the filter 7 is prone to turbulence due to obstruction by the annular inner wall or uneven airflow from the filter element. The two spiral blades 3 guide the airflow upwards along the spiral trajectory and then towards the central airflow, avoiding "artificially increased wind resistance" caused by turbulence and indirectly increasing the actual airflow volume.

[0037] like Figure 2 and Figure 8 As shown, the fan bracket 9 is equipped with an aromatherapy module 12, and an aromatherapy box 18 is slidably installed in the aromatherapy module 12. The aromatherapy box 18 contains an aromatherapy block 19. Since the aromatherapy box 18 is fixed to the outlet side of the centrifugal fan 10 in the fan bracket 9, it is located in a high-velocity area with a wind speed ≥5m / s in the air duct. The high-speed airflow directly washes the surface of the aromatherapy box 18, accelerating the diffusion of volatile substances and improving the aromatherapy efficiency by more than 30%.

[0038] The upper end of the cover 14 is provided with an air outlet grille 15, which is used to spray out purified air. The cover 14 is provided with an operation panel 16 for controlling the device. An air inlet grille 17 is provided between the centrifugal fan 10 and the filter 7.

[0039] Working principle:

[0040] First, when the equipment is started via the operation panel 16 on the top cover 14, the DC motor 11 installed on the fan bracket 9 starts to run. Its lower end drives the centrifugal fan 10 to rotate synchronously through the output shaft. The rotation of the centrifugal fan 10 will create a negative pressure environment inside the equipment. Under the action of negative pressure, the outside air to be purified enters the equipment from the gap between the bottom cover 1 and the lower shell 8 at the bottom of the lower shell 8, and then flows to the filter mechanism located in the lower shell 8 to start the purification process.

[0041] The second step involves the air entering the device first contacting the core component of the filtration mechanism—filter 7. The outermost layer of filter 7 is made of polyester fiber, which can directly intercept hair, dander, lint, and large dust particles (diameter ≥10μm) in the air, preventing such impurities from entering the subsequent core filtration stage and protecting the internal filter element. Subsequently, the air passes through the ultra-fine glass fiber HEPA filter (diameter ≤1μm, filtration accuracy up to H10-H14 level) in the middle layer of filter 7. This filter is formed into a dense filtration layer through hot-melt bonding, which can efficiently capture fine particles in the air (filtration efficiency of ≥99.97% for 0.3μm particles), completing the physical filtration stage and initially purifying the air.

[0042] The third step involves the air, after physical filtration, entering the filter 7. It first flows through a porous plastic mesh 6 (perpendicular to the air duct, covering the entire duct cross-section) between two spiral blades 3. This mesh 6 organizes the dispersed airflow into a uniform flow, preventing localized overly strong or no airflow. It also slightly obstructs the airflow, extending its residence time within the filter mechanism. Subsequently, guided by the two spiral blades 3, the uniform airflow flows upward along a spiral trajectory (the spiral blades 3 optimize airflow direction, reduce turbulence loss, and lower wind resistance). During this process, small UV-C LED beads 5 (small size, low energy consumption, low heat generation, and built-in wiring that doesn't occupy the air duct) equidistantly installed in the spiral grooves 4 on the surface of the spiral blades 3 emit ultraviolet light, activating the photocatalytic filter 2 (titanium dioxide TiO2 nano-coating) fixed to the inner wall of the filter 7. The activated photocatalytic filter 2 efficiently decomposes bacteria, viruses, and volatile organic compounds (VOCs, such as formaldehyde and benzene) in the airflow, completing air disinfection and deep purification.

[0043] In the fourth step, the airflow that has been disinfected and purified enters the centrifugal fan 10 through the air inlet grille 17 between the centrifugal fan 10 and the filter 7 (which can block a small amount of carbon powder and fiber that falls off from the filter element and protect the centrifugal fan 10). The centrifugal fan 10 centrifugally pressurizes the airflow by rotating, changing the airflow from a "low pressure and low speed" state to a "high pressure and high speed" state, and then delivers the pressurized airflow to the inside of the fan bracket 9.

[0044] In the fifth step, after the high-pressure airflow enters the fan bracket 9, it flows through the rear guide pressure boosting blades 13 fixed on its inner wall (the number of blades is 1.2-1.5 times the number of blades of the centrifugal fan 10, avoiding integer multiples of the centrifugal fan rotation frequency through modal analysis, suppressing resonance, and reducing the amplitude by 30%; the gap between the air inlet and the centrifugal fan 10 is 3-5mm). The windward curvature radius R of the rear guide pressure boosting blades 13 (satisfying the relationship R=D / 2(1+θ / 180), where D is the impeller diameter and θ is the blade installation angle of 20°-35°) is matched with the rotation direction of the centrifugal fan 10, which can further optimize the airflow direction, increase the outlet air pressure by 15%~20%, and make the wind speed reach 8-12m / s. At the same time, it ensures that the equipment air volume is ≥200m³ / h, the noise at a distance of 1m is ≤50dB(A), and ensures that the service life of the DC motor 11 exceeds 20,000 hours.

[0045] In the sixth step, the high-speed airflow optimized by the rear-guided pressurizing blades 13 flows through the aromatherapy module 12 inside the fan bracket 9. The aromatherapy box 18 (with built-in aromatherapy block 19) slidably installed inside the aromatherapy module 12 is in a high-velocity area with a wind speed of ≥5m / s in the air duct. The high-speed airflow directly washes the surface of the aromatherapy box 18, accelerating the diffusion of volatile substances in the aromatherapy block 19 (increasing the aromatherapy efficiency by more than 30%), so that the aromatherapy substances are fully integrated with the purified airflow. Finally, the clean airflow carrying the aromatherapy substances is discharged from the equipment through the air outlet grille 15 at the top of the cover 14, realizing the integrated air treatment effect of "purification + disinfection + aromatherapy".

[0046] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A multi-stage air purifier duct device, comprising a lower shell (8) and an upper cover (14) on the lower shell (8). Its features are: The lower shell (8) is provided with a filter mechanism for filtering air, and the filter mechanism is provided with a spiral mechanism for rectifying and disinfecting the airflow. The upper cover (14) is provided with a fan bracket (9), a DC motor (11) is installed on the fan bracket (9), a centrifugal fan (10) is fixedly installed at the lower end of the DC motor (11) through the output shaft, and a rear guide pressure boosting blade (13) is fixedly installed on the inner wall of the fan bracket (9).

2. The multi-stage air purifier duct device as described in claim 1, characterized in that, The filtration mechanism includes a filter (7), and a photocatalytic filter (2) is fixedly installed on the inner wall of the filter (7).

3. The multi-stage air purifier duct device as described in claim 2, characterized in that, The filter (7) is made of polyester fiber and ultra-fine glass fiber.

4. The multi-stage air purifier duct device as described in claim 3, characterized in that, The filter (7) is provided with a bottom cover (1) at its lower end, and the bottom cover (1) is fixedly installed at the lower end of the lower shell (8) by a snap fastener.

5. The multi-stage air purifier duct device as described in claim 4, characterized in that, The spiral mechanism includes two spiral blades (3), which are fixedly installed on the inner wall of the photocatalytic filter (2).

6. The multi-stage air purifier duct device as described in claim 5, characterized in that, Both of the spiral blades (3) have spiral grooves (4) on their upper surfaces, and small UV-C LED beads (5) are fixedly installed at equal intervals in the spiral grooves (4) of the two spiral blades (3).

7. The multi-stage air purifier duct device as described in claim 6, characterized in that, A porous plastic mesh (6) is fixedly installed between the two spiral blades (3).

8. The multi-stage air purifier duct device as described in claim 7, characterized in that, The fan bracket (9) is provided with an aromatherapy module (12), and an aromatherapy box (18) is slidably installed inside the aromatherapy module (12) provided on the fan bracket (9). An aromatherapy block (19) is provided inside the aromatherapy box (18).

9. The multi-stage air purifier duct device as described in claim 8, characterized in that, The upper end of the cover (14) is provided with an air outlet grille (15), and the upper cover (14) is provided with an operation panel (16).

10. The multi-stage air purifier duct device as described in claim 9, characterized in that, An air inlet grille (17) is provided between the centrifugal fan (10) and the filter (7).

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