A multi-stage air deflector air cleaner duct device

Abstract

The application provides a multistage air guide air purifier air duct device, and relates to the technical field of air purifiers, which comprises a lower shell, an upper cover arranged on the lower shell, a filtering mechanism arranged in the lower shell for filtering air, a spiral mechanism arranged in the filtering mechanism for air flow rectification and sterilization, a fan support arranged in the upper cover, and a direct current motor mounted on the fan support. In the application, a specially designed rear guide booster blade (the number of blades is set to 1.2-1.5 times the number of centrifugal fan blades, and the number of blades can be selected as 7, 9 or 11 odd blades) is fixedly installed on the inner wall of the fan support, the number ratio of the centrifugal fan and the rear guide booster blade is accurately determined by means of modal analysis technology, the integer multiple of the rotation frequency of the centrifugal fan is avoided, the resonance phenomenon in the equipment operation process is effectively inhibited (the amplitude is reduced by 30%), and the windward surface curvature radius R of the rear guide booster blade is matched with the rotation direction of the centrifugal fan.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of air purifiers, and more particularly relates to a multi-stage air flow guiding air purifier air duct device. BACKGROUND

[0002] In the market research and product performance testing of air purifier air duct devices, the present application company found that the same products in the current industry generally have four core technical pain points, which seriously restrict the product use experience and comprehensive performance. The specific problems are as follows:

[0003] First, the existing products with aromatherapy function are mostly placed in the low flow area of the air duct with a wind speed of less than or equal to 3 m / s. Due to the insufficient airflow scouring intensity, the volatilization rate of volatile substances in the aromatherapy block is generally low, which not only leads to slow fragrance diffusion and uneven indoor fragrance coverage, but also causes waste of aromatherapy substances, and it is difficult to meet the user's demand for "rapid fragrance creation";

[0004] Second, most products use AC motors to drive the fan to rotate. Such motors not only have significantly higher energy consumption (more than 30% higher than high-efficiency DC motors), but also have shorter service life (usually less than 15,000 hours), increasing the user's long-term use cost. At the same time, the output power stability of the AC motor is poor, and the fan is prone to insufficient wind pressure when driving, which makes it difficult for the actual air output of the device to exceed 200 m³ / h, limits the purification efficiency, and the electromagnetic noise and mechanical noise generated during operation are superimposed, the noise at a distance of 1 m is often higher than 55 dB(A), and the adaptability to noise-sensitive scenes (such as bedrooms and study rooms) is extremely poor;

[0005] Third, although some products are provided with rear guide vanes, they are not designed from the perspective of structural matching: neither the number ratio of the rear guide vanes to the fan blades is determined through modal analysis (the optimal ratio of 1.2-1.5 times is not followed), nor the gap between the rear guide vane inlet and the fan is controlled (deviating from the reasonable range of 3-5 mm), which causes the rear guide vanes and the fan to easily produce resonance when rotating, significantly increases the amplitude, and at the same time causes airflow turbulence, which not only further aggravates the noise problem, but also causes wind pressure loss to exceed 10%, and cannot realize effective pressurization;

[0006] Fourth, the air duct system lacks a scientific airflow guiding structure. After the air flow passes through the filter, it is easy to produce significant turbulence due to the blocking of the annular inner wall and the uneven air outlet of the filter element. On the one hand, it causes virtual increase of airflow flow resistance, and the actual air output is reduced by 15%-20% compared with the designed value, and the air purification efficiency is greatly reduced (especially the time-consuming for large space purification is prolonged); on the other hand, the airflow impact and friction caused by turbulence will produce additional noise, which, together with the noise of the motor and the fan, further deteriorates the noise level of the device during operation, seriously affecting the user's experience.

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

[0008] To solve the above technical problems, the present application provides a multi-stage flow guide air purifier air duct device to solve the problem that the air duct system lacks a scientific air flow guide structure, and after the air flow passes through the filter, significant turbulence is generated due to the blocking of the annular inner wall and uneven air outlet of the filter element.

[0009] A multi-stage flow guide air purifier air duct device, comprising a lower shell, an upper cover is arranged on the lower shell, a filter mechanism for filtering air is arranged in the lower shell, a spiral mechanism for straightening and sterilizing the air flow is arranged in the filter mechanism, a fan bracket is arranged in the upper cover, a DC motor is mounted on the fan bracket, a centrifugal fan is fixedly installed on the lower end of the DC motor through an output shaft, and a rear guide booster blade is fixedly installed on the inner wall of the fan bracket.

[0010] Preferably, the filter mechanism comprises a filter, a photocatalyst filter screen is fixedly installed on the inner wall of the filter, the filter is made of polyester fiber and ultra-fine glass fiber, a bottom cover is arranged at the lower end of the filter, and the bottom cover is fixedly installed at the lower end of the lower shell by buckling.

[0011] Preferably, the spiral mechanism comprises two spiral blades, the two spiral blades are fixedly installed on the inner wall of the photocatalyst filter screen, a spiral groove is formed on the upper surface of each of the two spiral blades, a small UV-CLED lamp bead is fixedly installed in the spiral groove of each of the two spiral blades at equal intervals, and a plastic porous uniform distribution net is fixedly installed between the two spiral blades.

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

[0013] Preferably,

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

[0015] In the application, by fixing and installing the specially designed rear guide booster blades (the number of blades is set to 1.2-1.5 times of the number of centrifugal fan blades, and the number of blades can be selected as 7, 9 or 11 odd blades) on the inner wall of the fan support, and by means of modal analysis technology to accurately determine the number ratio of the centrifugal fan and the rear guide booster blades, the integer multiple of the centrifugal fan rotation frequency is avoided, and the resonance phenomenon during the operation of the equipment is effectively suppressed (the amplitude is reduced by 30%), and at the same time, the windward surface curvature radius R of the rear guide booster blade is matched with the rotation direction of the centrifugal fan, this design not only can significantly suppress the airflow turbulence and reduce the energy loss in the airflow flow process, but also can increase the air outlet pressure by 15%-20%, the wind speed of the clean air reaches 8-12m / s, the overall air volume of the equipment is greater than or equal to 200m³ / h, and finally the high-efficiency airflow booster effect of increasing the diffusion speed of clean air by 30% is realized, and the coverage range and efficiency of air purification are greatly improved.

[0016] In the application, the aromatherapy module is arranged on the fan support, and the aromatherapy box is integrated in the aromatherapy module in a sliding installation manner (convenient for subsequent replacement of the aromatherapy block), and the installation position of the aromatherapy box is accurately positioned at the outlet side of the centrifugal fan in the fan support - this area is a high-flow area with a wind speed greater than or equal to 5m / s in the air duct. When the equipment is running, the high-speed airflow directly washes the surface of the aromatherapy box, quickly carries away the aroma substances volatilized from the aromatherapy block in the aromatherapy box, significantly accelerates the diffusion rate of the aromatherapy substances (compared with the traditional aromatherapy installation method, the aromatherapy volatilization rate is increased by 50%), and 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 scenes (such as sleep-aiding aromatherapy in a family bedroom, freshening aromatherapy in a living room, refreshing aromatherapy in an office, etc.), perfectly adapt to multi-scene aromatherapy requirements, realize intelligent aromatherapy release function, and improve the comfort of indoor environment while purifying air.

[0017] In the application, by adopting the design of the rear guide booster blade with an odd number of blades (7, 9 or 11), and cooperating with the direct-current motor driven centrifugal fan operation with the low-noise operation characteristic, the noise generation is double controlled from two aspects of structure design and core component selection: the rear guide booster blade with an odd number of blades can optimize the airflow flow trajectory, reduce the turbulence noise generated by the impact and friction between the airflow and the blade, and avoid the resonance frequency with the centrifugal fan to avoid the superposition of resonance noise; and compared with the traditional alternating-current motor, the electromagnetic noise and mechanical noise during the operation of the direct-current motor are lower, and the two cooperate to make the noise of the equipment ≤50dB(A) at a distance of 1m, which is 5dB(A) lower than the overall noise of the air duct device of the traditional air purifier, and the super-silent operation effect is realized. Even in the scenes sensitive to noise such as bedroom and study, the user's rest and work will not be disturbed.

[0018] In the application, by selecting a DC motor as the core power component for driving the centrifugal fan to operate, the DC motor has a significant advantage in energy consumption compared to the AC motor commonly used in traditional air purifiers, which reduces energy consumption by 30% compared to traditional motors. At the same time, combined with the optimization design of the overall air duct of the equipment (such as the rear guide booster blade to improve wind pressure, the spiral blade to reduce turbulence loss, etc.), the energy waste in the airflow flow process is reduced, the comprehensive energy efficiency of the equipment reaches the first level standard, and the long-term operation cost of the equipment is effectively reduced.

[0019] In the application, two spiral blades are fixedly installed on the inner wall of the photocatalyst filter screen of the filtering mechanism, and a spiral installation method is adopted to adapt the blades to the air duct structure. When the airflow preliminarily purified by the filtering mechanism enters the inside of the photocatalyst filter screen, the two spiral blades can actively guide the airflow to flow upward along the spiral track and gradually converge to the middle air duct, effectively solving the turbulence phenomenon easily caused by the problems such as the blocking of the annular inner wall of the internal air duct of the filter and the uneven air outlet of the filter element, avoiding the "virtual increase of wind resistance" caused by turbulence (i.e. the airflow consumes additional energy due to disordered collision, causing the actual effective air volume to decrease), reducing the energy loss in the airflow flow process, indirectly improving the actual air volume of the equipment, and making the airflow flow more smoothly, further optimizing the airflow direction of the entire air duct system, and laying a stable airflow foundation for the subsequent disinfection, purification and pressure boosting delivery links.

[0020] In the application, spiral grooves are formed on the upper surfaces of the two spiral blades, and small UV-CLED lamp beads are fixedly installed in the spiral grooves at equal intervals. The characteristics of both are fully utilized to achieve deep complementation: on the one hand, the small UV-CLED lamp beads are small in size and can be directly integrated in the spiral grooves on the surface of the spiral blades without occupying the airflow channel, and have low energy consumption and low heating, so they will not change the airflow state due to high temperature or accelerate the aging of the blades, and the built-in circuit design can also avoid interference to the airflow; on the other hand, the spiral blades themselves have the characteristic of guiding airflow, and the plastic porous uniform distribution net fixedly installed between the two spiral blades (the net surface is perpendicular to the air duct and covers the entire air duct cross section) can comb the "dispersed airflow" into "uniform airflow" and slightly block the airflow, prolonging the residence time of the airflow in the spiral blade area, so that the airflow can more fully contact the ultraviolet light emitted by the UV-CLED lamp beads. The ultraviolet light can activate the photocatalyst filter screen (titanium dioxide TiO2 nano coating) to efficiently decompose bacteria, viruses and VOCs (such as formaldehyde and benzene) in the airflow, avoiding the problem that some microorganisms are not irradiated due to too fast airflow, and the purification is not sufficient, and the plastic porous uniform distribution net can also block a small amount of carbon powder and fibers falling from the filter element, protecting the subsequent centrifugal fan. Ultimately, through the complementation of the characteristics of both, the uniformity and efficiency of sterilization and deep purification are significantly improved, achieving a purification effect of 1+1>2. BRIEF DESCRIPTION OF DRAWINGS

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

[0022] Figure 2 is a schematic diagram of the fan support structure of the present application;

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

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

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

[0026] Figure 6 is a schematic diagram of the helical blade structure of the present application;

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

[0028] Figure 8 is a schematic diagram of the structure of the present application Figure 2 at A.

[0029] In the figure, the correspondence between the component names and the figure numbers is as follows: 1, bottom cover; 2, photocatalyst filter screen; 3, helical blade; 4, helical groove; 5, small UV-CLED lamp bead; 6, plastic porous uniform distribution screen; 7, filter; 8, lower shell; 9, fan support; 10, centrifugal fan; 11, DC motor; 12, aromatherapy module; 13, rear guide booster blade; 14, upper cover; 15, air outlet grille; 16, operation panel; 17, air inlet grille; 18, aromatherapy box; 19, aromatherapy block. DETAILED DESCRIPTION

[0030] The embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0031] Please refer to Figure 1 - Figure 8The application provides a multi-stage air guide air purifier air duct device, which comprises a lower shell 8, an upper cover 14 arranged on the lower shell 8, a filtering mechanism arranged in the lower shell 8 and used for filtering air, a spiral mechanism arranged in the filtering mechanism and used for rectifying and disinfecting air flow, a fan bracket 9 arranged in the upper cover 14, a direct current motor 11 arranged on the fan bracket 9, a centrifugal fan 10 fixedly arranged at the lower end of the direct current motor 11 through an output shaft, and an odd number (7 / 9 / 11) of rear guide booster blades 13 fixedly arranged on the inner wall of the fan bracket 9, wherein the number of the rear guide booster blades 13 is 1.2-1.5 times the number of blades of the centrifugal fan 10, the number of blades of the centrifugal fan 10 and the number of blades of the rear guide booster blades 13 are determined through modal analysis, the integer multiple of the rotation frequency of the centrifugal fan 10 is avoided, and resonance is inhibited (amplitude reduction of 30%), the air inlet of the rear guide booster blades 13 is spaced apart from the centrifugal fan 10 by 3-5 mm, the air volume is greater than or equal to 200 m³ / h, the noise is less than or equal to 50 dB(A) (1 m distance), and the service life of the direct current motor 11 is more than 20,000 hours.

[0032] The curvature radius R of the windward surface of the rear guide booster blades 13 is matched with the rotation direction of the centrifugal fan 10, and the following relationship is met: R=D / 2(1+θ / 180);

[0033] D is the diameter of the wind wheel, and θ is the blade installation angle (20°-35°).

[0034] Therefore, the air guide surface curvature can be optimized to make the air outlet grille 8-12 m / s, and the air outlet grille 15%-20% wind pressure is increased.

[0035] As shown in Figure 4 , Figure 5 and Figure 7 , the filtering mechanism comprises a filter 7, a photocatalyst filter screen 2 fixedly arranged on the inner wall of the filter 7, and polyester fibers used on the outermost layer of the filter 7, which can effectively filter hair, dander, fiber fluff, and large particle dust, and protect subsequent filter elements. The middle layer of the HEPA filter screen is made of extremely fine glass fiber (diameter ≤1 μm) and is bonded into a dense layer through heat melting, so that the filtering precision is high (H10-H14 level, and the filtration efficiency for 0.3 μm particles is greater than or equal to 99.97%). The lower end of the filter 7 is provided with a bottom cover 1, and the bottom cover 1 is fixedly arranged at the lower end of the lower shell 8 through buckling.

[0036] As shown in 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 photocatalyst filter screen 2 by the installation of the spiral, the upper surfaces of the two spiral blades 3 are provided with spiral grooves 4, and small UV-CLED lamp beads 5 are fixedly installed in the spiral grooves 4 of the two spiral blades 3. The small UV-CLED lamp beads 5 are small in size and can be directly integrated on the surface of the spiral blade 3, without occupying the air flow channel, and have low energy consumption and low heating, so that the air flow state will not be changed due to high temperature, and the blade will not be accelerated to age. The circuit is installed inside the spiral blade 3 and is connected with the overall power supply control component of the device. The plastic porous uniform distribution net 6 is fixedly installed between the two spiral blades 3. The net surface of the plastic porous uniform distribution net 6 is perpendicular to the air duct (annular, covering the entire air duct cross section), so that the "dispersed air flow" coming out from the inside of the filter element can pass through the uniform distribution net and become "uniform air flow" before entering the central area, avoiding the problem of "local air flow being too strong and local air flow being non-existent", and can also play a role of slightly blocking the air flow, so that the air flow can stay at the position of the spiral blade 3, thereby improving the uniformity of the small UV-CLED lamp beads 5 inside the spiral blade 3 cooperating with the photocatalyst filter screen 2 to kill bacteria (the photocatalyst filter screen 2 is a titanium dioxide TiO2 nano coating, which can decompose bacteria, viruses and VOC (formaldehyde, benzene) under light), avoiding that some microorganisms are not irradiated due to too fast air flow, and blocking a small amount of carbon powder and fibers falling from the filter element, protecting the subsequent fan. The design of the two spiral blades 3 can optimize the air flow direction and reduce turbulence loss. The air flow in the air duct inside the filter 7 is prone to turbulence due to the problem of blocking by the annular inner wall or uneven air outlet of the filter element. The two spiral blades 3 can guide the air flow to flow upward along the spiral track and then converge to the middle air duct, avoiding the "virtual increase of wind resistance" caused by turbulence, and indirectly improving the actual air output.

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

[0038] The upper end of the upper cover 14 is provided with an air outlet grille 15 for purifying air to be sprayed out. The upper cover 14 is provided with an operation panel 16 for controlling the device. The centrifugal fan 10 and the filter 7 are provided with an air inlet grille 17.

[0039] Working principle:

[0040] The first step, when the device is started through the operation panel 16 of the upper cover 14, the DC motor 11 installed on the fan support 9 starts to operate, and the lower end drives the centrifugal fan 10 to rotate synchronously through the output shaft. The rotation of the centrifugal fan 10 will form a negative pressure environment in the device. Under the action of negative pressure, the outside air to be purified enters the device from the gap between the bottom cover 1 and the lower shell 8 at the lower end of the lower shell 8, and then flows to the filtering mechanism in the lower shell 8, and the purification process is started.

[0041] The second step, the air entering the device first contacts the core component of the filtering mechanism-the filter 7. The outermost layer of the filter 7 is made of polyester fiber material, which can directly intercept hair, dander, fiber fluff and large particle dust (diameter ≥10μm) in the air, so as to avoid such impurities entering the subsequent core filtering link and protect the internal filter element. Then the air passes through the extremely fine glass fiber HEPA filter screen (diameter ≤1μm, filtration precision reaches H10-H14 level) in the middle layer of the filter 7. The filter screen forms a dense filter layer by hot melt bonding, which can efficiently capture fine particles in the air (filtration efficiency for 0.3μm particles ≥99.97%), complete the physical filtration stage, and preliminarily purify the air.

[0042] The third step, the air filtered by the physical filter enters the inside of the filter 7, first flows through the plastic porous uniform distribution net 6 between the two spiral blades 3 (the net surface is perpendicular to the air duct and covers the entire air duct section), which can comb the "dispersed airflow" into "uniform airflow", avoid the problem of "local airflow too strong, local no wind", and slightly block the airflow to prolong its residence time in the filtering mechanism. Then, under the guidance of the two spiral blades 3, the uniform airflow flows upward along the spiral trajectory (the spiral blade 3 can optimize the airflow direction, reduce turbulence loss, and reduce air resistance). In this process, the small UV-CLED lamp beads 5 (small in size, low in energy consumption and heat generation, and with internal wiring without occupying the air duct) installed in the equidistant spiral groove 4 on the surface of the spiral blade 3 emit ultraviolet light, which activates the photocatalyst filter screen 2 (titanium dioxide TiO2 nano coating) fixed on the inner wall of the filter 7. The activated photocatalyst filter screen 2 can efficiently decompose bacteria, viruses and volatile organic compounds (VOCs such as formaldehyde and benzene) in the airflow, complete air disinfection and deep purification.

[0043] The fourth step, the airflow that has completed disinfection and purification enters the inside of the centrifugal fan 10 through the air inlet grille 17 (which can block a small amount of carbon powder and fibers falling from the filter element, protecting the centrifugal fan 10) between the centrifugal fan 10 and the filter 7. The centrifugal fan 10 pressurizes the airflow by rotation, converts the airflow from "low pressure and low speed" to "high pressure and high speed", and delivers the pressurized airflow to the inside of the fan support 9.

[0044] In the fifth step, after the high-pressure airflow enters the fan support 9, it flows through the rear guide booster blades 13 fixed to the inner wall of the fan support 9 (the number of blades is 1.2-1.5 times the number of blades of the centrifugal fan 10, the resonance is suppressed by avoiding the integer multiple of the rotation frequency of the centrifugal fan through modal analysis, and the amplitude is reduced by 30%; the gap between the air inlet and the centrifugal fan 10 is 3-5 mm), the windward surface curvature radius R of the rear guide booster blades 13 (satisfying the relationship R=D / 2(1+θ / 180), wherein D is the diameter of the wind wheel, 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 air pressure at the air outlet by 15%-20%, and make the wind speed reach 8-12 m / s, while ensuring that the equipment air volume is ≥200 m³ / h, the noise at a distance of 1 m is ≤50 dB(A), and the service life of the direct-current motor 11 is more than 20,000 hours.

[0045] In the sixth step, the high-speed airflow optimized by the rear guide booster blades 13 flows in the fan support 9, and flows through the aromatherapy module 12. The aromatherapy box 18 (with an aromatherapy block 19) slidably installed in the aromatherapy module 12 is located in a high-flow area with a wind speed of ≥5 m / s in the air duct. The high-speed airflow directly washes the surface of the aromatherapy box 18, accelerates the diffusion of volatile substances in the aromatherapy block 19 (the aromatherapy efficiency is increased by more than 30%), and makes the aromatherapy substances fully mix 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 upper end of the upper cover 14, realizing the air treatment effect of “purification+disinfection+aromatherapy” integration.

[0046] The embodiments of the present application are given for the purpose of illustration and description, and are not exhaustive or limit the present application to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical application of the present application, and to enable those of ordinary skill in the art to understand the present application so as to design various embodiments with various modifications suitable for specific purposes.

Claims

1. A multi-stage air purification device, comprising a lower shell (8) provided with an upper cover (14); a filter mechanism for filtering air is arranged in the lower shell (8), and a spiral mechanism for straightening and sterilizing air flow is arranged in the filter mechanism; characterized in that wherein a fan bracket (9) is arranged in the upper cover (14), a direct current motor (11) is mounted on the fan bracket (9), a centrifugal fan (10) is fixedly installed at the lower end of the direct current motor (11) through an output shaft, and a rear guide booster blade (13) is fixedly installed on the inner wall of the fan bracket (9); wherein the filter mechanism comprises a filter (7), a photocatalyst filter screen (2) is fixedly installed on the inner wall of the filter (7), the spiral mechanism comprises two spiral blades (3) fixedly installed on the inner wall of the photocatalyst filter screen (2), spiral grooves (4) are formed on the upper surfaces of the two spiral blades (3), small UV-CLED lamp beads (5) are fixedly installed in the spiral grooves (4) of the two spiral blades (3) at equal intervals, a plastic porous uniform distribution screen (6) is fixedly installed between the two spiral blades (3), and an air inlet grille (17) is arranged between the centrifugal fan (10) and the filter (7). The filter (7) is made of polyester fiber and extremely fine glass fiber.

2. The multi-stage air cleaner duct assembly of claim 1, wherein, A bottom cover (1) is arranged at the lower end of the filter (7), and the bottom cover (1) is fixedly installed at the lower end of the lower shell (8) by buckling.

3. The multi-stage air cleaner duct assembly of claim 2, wherein: A fragrance module (12) is arranged on the fan bracket (9), a fragrance box (18) is slidingly installed in the fragrance module (12) arranged on the fan bracket (9), and a fragrance block (19) is arranged in the fragrance box (18).

4. The multi-stage air cleaner duct assembly of claim 3, wherein, An air outlet grille (15) is arranged at the upper end of the upper cover (14), and an operation panel (16) is arranged on the upper cover (14).

5. The multi-stage air cleaner duct assembly of claim 4, wherein: An air outlet grille (15) is arranged at the upper end of the upper cover (14), and an operation panel (16) is arranged on the upper cover (14).

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