Front filtering assembly for centrifugal fan

Abstract

The invention belongs to the technical field of filter assemblies, and particularly relates to a front filter assembly for a centrifugal fan, the front filter assembly comprises a filter box with a cam-shaped section, communicating ports are formed in the left and right ends of the filter box and located at the upper circle center position, and the two communicating ports communicate with communicating pipes; the ends, away from the communicating opening, of the two communicating pipes jointly communicate with a mounting pipe, and the mounting pipe is connected with an air inlet flange of the centrifugal fan. An air inlet arc opening is formed in the center of the upper end of the filter box, a movable filter mechanism is arranged in the filter box, and the movable filter mechanism comprises two filter unit boxes which are arranged in a left-right spaced mode. The filter assembly has the advantages that through an innovative mechanical structure and automatic design, the problem of pain points of a traditional filter assembly is solved, and the filter assembly has high efficiency, durability and easiness in maintenance and has remarkable practical value and market prospects.

Description

Technical Field

[0001] This invention relates to the field of filter assembly technology, and more particularly to a pre-filter assembly for centrifugal fans. Background Technology

[0002] Centrifugal fans, as key equipment widely used in industry, construction, and environmental protection, primarily function to generate airflow through a high-speed rotating impeller for various purposes such as ventilation, dust removal, and cooling. However, in actual operation, the air drawn into centrifugal fans often contains a large amount of dust, particulate matter, and other impurities. If these impurities directly enter the fan's interior, they will not only accelerate the wear of the impeller and casing, reducing the equipment's lifespan, but may also affect the fan's operating efficiency and even lead to equipment failure. Therefore, installing a high-efficiency and reliable filter assembly before the centrifugal fan's air inlet is an important measure to ensure the long-term stable operation of the equipment.

[0003] Traditional centrifugal fan pre-filters mostly use fixed filter structures. While this design is simple, it has several shortcomings in practical use. First, during the filtration process, dust easily accumulates on the filter surface, causing blockages, increasing airflow resistance, raising fan energy consumption, and reducing filtration efficiency. Second, cleaning and maintaining the filter requires shutdown and disassembly, which is not only cumbersome but also disrupts production continuity. Furthermore, traditional filters have limited filtration area, making them unsuitable for high-dust environments, and the high frequency of filter replacement increases maintenance costs. Against this backdrop, this invention proposes a pre-filter assembly for centrifugal fans. Through innovative mechanical structure and automated design, it effectively addresses the pain points of traditional filter assemblies. This assembly employs a rotating flexible filter screen and an automatic dust removal mechanism, ensuring continuous cleanliness of the filter screen during operation and preventing dust accumulation. Simultaneously, the alternating operation design of the dual filter unit boxes enables maintenance without shutting down the system, significantly improving equipment availability and maintenance efficiency. Furthermore, the modular design and optimized lubrication and maintenance further reduce maintenance costs, giving it outstanding practical value and market competitiveness in high-dust environments. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the background art by providing a pre-filter assembly for centrifugal fans.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a pre-filter assembly for a centrifugal fan, comprising a filter box with a cam-shaped cross-section, wherein both ends of the filter box and the center position at the top are provided with connecting ports, both connecting ports are connected to connecting pipes, and the ends of the two connecting pipes away from the connecting ports are connected to an installation pipe, wherein the installation pipe is connected to the air inlet flange of the centrifugal fan. An air inlet arc is provided at the center of the upper end of the filter box. A movable filter mechanism is provided inside the filter box. The movable filter mechanism includes two filter unit boxes arranged left and right at intervals. The two filter unit boxes are fixedly connected by a fixing rod. Each filter unit box includes two box plates arranged left and right at intervals. The box plates are cam-shaped and are slidably sealed to the inner wall of the filter box. A transmission structure is provided between the two corresponding box plates on the left and right. A flexible filter screen is installed on the transmission structure. An electric telescopic rod is fixedly installed on the left end of the filter box. The telescopic end of the electric telescopic rod extends into the filter box and is fixedly connected to the filter unit box on the left side. A dust removal arc is opened at the center of the lower end of the filter box. A dust collection box communicating with the dust removal arc is fixedly connected to the lower end of the filter box.

[0006] In the aforementioned pre-filter assembly for a centrifugal fan, the transmission structure includes a first gear and a transmission tube rotatably connected between two box plates. The first gear is coaxially arranged with the upper center of the box plate, and the transmission tube is coaxially arranged with the lower center of the box plate. The inner hole of the transmission tube has a regular hexagonal structure. A second gear is fixedly sleeved on the transmission tube. A transmission chain is sleeved on both the first gear and the second gear. Each of the two corresponding box plates has a groove of the same shape on its opposite side. A rubber slide is sealed and slidably connected in each of the two slides. Multiple evenly distributed connecting crossbars are fixedly connected between the two rubber slides. Each connecting crossbar is movably connected to the transmission chain through a connector. The flexible filter screen is fixedly connected to each connecting crossbar.

[0007] In the aforementioned pre-filter assembly for a centrifugal fan, air outlets are provided on both of the two box plates near the two connecting ports. A transmission rod is rotatably connected between the two inner walls of the filter box. The transmission rod has a regular hexagonal cross-section and passes through and is slidably connected to two transmission pipes. A drive motor that drives the transmission rod to rotate is fixedly installed on the outside of the filter box.

[0008] In the aforementioned pre-filter assembly for a centrifugal fan, a sealing disc matching the inner diameter of the connecting pipe is fixedly connected to each of the two box plates near the two connecting ports.

[0009] In the aforementioned pre-filter assembly for a centrifugal fan, a cleaning mechanism is provided inside the ash collection box. The cleaning mechanism includes two brush plates distributed about front and rear of the ash cleaning arc. The two brush plates are inclined and fixedly connected to the corresponding inner wall of the ash collection box by a telescopic rod. A threaded sleeve is fixedly connected to one end of each brush plate near the inner wall of the ash collection box. Threaded rods are rotatably connected through both the front and rear ends of the ash collection box. The threaded rods are threadedly connected to the corresponding threaded sleeves. A rotating block is fixedly sleeved at the end of the threaded rod outside the ash collection box.

[0010] In the aforementioned pre-filter assembly for a centrifugal fan, a pull-out box is slidably inserted into one end of the ash collection box.

[0011] In the aforementioned pre-filter assembly for a centrifugal fan, insert blocks are fixedly inserted through both of the two box plates near the two connecting ports. An oil injection pipe is inserted through the insert block. One end of the oil injection pipe inside the filter unit box is positioned towards the second gear, and the other end of the oil injection pipe outside the filter unit box is connected to an oil injection valve port.

[0012] In the aforementioned pre-filter assembly for a centrifugal fan, the filter box has insertion ports at both the left and right ends that correspond to the insertion blocks. Both insertion ports have sealing covers on their outer sides, and the sealing covers are rotatably connected to the outer wall of the filter box via a torsion spring shaft.

[0013] Compared with existing technologies, the advantages of this invention are: The rotating flexible filter design, combined with the drive motor and transmission structure, allows the filter to rotate continuously during the filtration process, preventing dust from accumulating and ensuring uniform utilization of the filtration area, thus significantly improving filtration efficiency and filter lifespan.

[0014] The cleaning arc and inclined brush plate work together to automatically brush off the attached dust when the filter screen rotates. The dust is collected in the dust collection box and can be cleaned through the pull-out box, achieving cleaning without stopping the machine, reducing maintenance frequency, and ensuring the continuous and efficient operation of the fan.

[0015] The two filter unit boxes are controlled by an electric telescopic rod to move laterally and take turns to perform filtration tasks. This ensures that when one set of filters is working, the other set is in standby or maintenance mode, achieving seamless switching and improving equipment availability.

[0016] The design of the insert and oil injection pipe allows for direct injection of lubricating oil to lubricate gears and drive chains without disassembling components, simplifying the maintenance process and reducing maintenance costs.

[0017] In summary, this invention, through its innovative mechanical structure and automated design, solves the pain points of traditional filter components, combining high efficiency, durability, and ease of maintenance, and has significant practical value and market prospects. Attached Figure Description

[0018] Figure 1 This is a perspective view of a pre-filter assembly for a centrifugal fan proposed in this invention; Figure 2 This is a perspective view of a filter box in a pre-filter assembly for a centrifugal fan, as proposed in this invention. Figure 3 This is a partial cross-sectional view of a filter box in a pre-filter assembly for a centrifugal fan according to the present invention. Figure 4 This is a perspective view of a movable filter mechanism in the pre-filter assembly of a centrifugal fan, as proposed in this invention. Figure 5 This is a perspective view of a filter unit box in a pre-filter assembly for a centrifugal fan, as proposed in this invention. Figure 6 This is a perspective view of a filter unit box in a pre-filter assembly for a centrifugal fan, as proposed in this invention. Figure 7 This is a perspective view of a transmission architecture in a pre-filter assembly for a centrifugal fan, as proposed in this invention. Figure 8 This is a perspective view of a box plate in a pre-filter assembly for a centrifugal fan according to the present invention. Figure 9 This is a perspective view of a dust collection box in a pre-filter assembly for a centrifugal fan, as proposed in this invention. Figure 10 for Figure 9 Enlarged structural diagram at point A in the middle.

[0019] In the diagram: 1. Installation pipe, 2. Filter box, 3. Connecting port, 4. Connecting pipe, 5. Air inlet arc, 6. Box plate, 7. First gear, 8. Transmission pipe, 9. Second gear, 10. Transmission chain, 11. Slide groove, 12. Rubber slide strip, 13. Connecting crossbar, 14. Flexible filter screen, 15. Air outlet, 16. Electric telescopic rod, 17. Transmission rod, 18. Drive motor, 19. Sealing disc, 20. Dust removal arc, 21. Dust collection box, 22. Telescopic rod, 23. Brush plate, 24. Threaded sleeve, 25. Threaded rod, 26. Rotary block, 27. Pull-out box, 28. Insert block, 29. Oil injection pipe, 30. Sealing cover plate. Detailed Implementation

[0020] The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0021] Reference Figures 1-10 A pre-filter assembly for a centrifugal fan includes a filter box 2 with a cam-shaped cross-section, consisting of two concentric circles, and having a structure that is wider at the top and narrower at the bottom. Both ends of the filter box 2, specifically at the upper concentric circle, have connecting ports 3. Each connecting port 3 is connected to a connecting pipe 4. The ends of the two connecting pipes 4 furthest from the connecting ports 3 are connected to a mounting pipe 1. The mounting pipe 1 is connected to the air inlet flange of the centrifugal fan. When the centrifugal fan is operating, air is drawn into the filter box 2 through the connecting pipes 4, and the air is filtered by the filter box 2.

[0022] An air inlet 5 is located at the center of the upper end of the filter box 2, through which air enters the filter box 2. The filter box 2 contains a movable filtration mechanism, which includes two filter unit boxes spaced apart horizontally. The two filter unit boxes are fixedly connected by a fixing rod. Each filter unit box includes two cam-shaped plates 6 spaced apart horizontally and are slidably sealed to the inner wall of the filter box 2. A transmission mechanism is provided between the two corresponding cam plates 6, connecting them. A flexible filter screen 14, made of metal, is installed on the transmission mechanism to filter the air. Specifically, the two filter unit boxes can move horizontally synchronously within the filter box 2. When one filter unit box is located at the air inlet 5, the filter box 2 begins to filter the air.

[0023] The transmission structure includes a first gear 7 and a transmission tube 8 rotatably connected between two box plates 6. The first gear 7 is coaxially arranged with the upper center of the box plate 6, and the transmission tube 8 is coaxially arranged with the lower center of the box plate 6. The inner hole of the transmission tube 8 is a regular hexagonal structure. A second gear 9 is fixedly sleeved on the transmission tube 8. A transmission chain 10 is sleeved on both the first gear 7 and the second gear 9. Each of the two corresponding box plates 6 has a groove 11 of the same shape on one side. A rubber slide strip 12 is sealed and slidably connected in each of the two grooves 11. Multiple evenly distributed connecting crossbars 13 are fixedly connected between the two rubber slide strips 12. Each connecting crossbar 13 is movably connected to the transmission chain through a connector. A flexible filter screen 14 is fixedly connected to each connecting crossbar 13. When the first gear 7 and the second gear 9 rotate through the transmission chain 10, the flexible filter screen 14 can rotate together with the transmission chain 10 under the limitation of the connecting crossbars 13 and the rubber slide strips 12.

[0024] Air outlets 15 are provided on both box plates 6 near the two connecting ports 3. Air filtered by the flexible filter 14 can be discharged from the filter unit box through the air outlets 15 and then enter the filter box 2. A transmission rod 17 is rotatably connected between the two inner walls of the filter box 2. The transmission rod 17 has a regular hexagonal cross-section and passes through and is slidably connected to the two transmission pipes 8. A drive motor 18 is fixedly installed on the outside of the filter box 2 to drive the transmission rod 17 to rotate. When the drive motor 18 drives the transmission rod 17 to rotate, it can drive the two transmission pipes 8 to rotate together, thereby controlling the rotation of the two corresponding second gears 9. When the second gears 9 rotate, the first gear 7 and the transmission chain 10 are synchronously driven, thereby controlling the rotation of the flexible filter 14. When the flexible filter 14 is rotating, it can effectively avoid the concentrated accumulation of dust and impurities during air filtration, so that each position of the flexible filter 14 can effectively perform filtration work, thereby improving the filtration effect of the flexible filter 14.

[0025] An electric telescopic rod 16 is fixedly installed at the left end of the filter box 2. The telescopic end of the electric telescopic rod 16 extends into the filter box 2 and is fixedly connected to the filter unit box on the left. The electric telescopic rod 16 can drive the two filter unit boxes to move laterally, so that the two can perform filtration work alternately. A sealing plate 19 matching the inner diameter of the connecting pipe 4 is fixedly connected to each of the two box plates 6 near the two connecting ports 3. When one filter unit box is located at the air inlet arc 5, the sealing plate 19 on that filter unit box is located inside the filter box 2, while the sealing plate 19 on the other filter unit box is sealed and inserted into the corresponding connecting pipe 4, thus ensuring that only one side of the connecting pipe 4 serves as the air intake. Specifically, the electric telescopic rod 16 can effectively move the two filter unit boxes, putting them in the working state and the stopped state respectively.

[0026] A cleaning arc 20 is provided at the center of the lower end of the filter box 2. A dust collection box 21 communicating with the cleaning arc 20 is fixedly connected to the lower end of the filter box 2. A cleaning mechanism is provided inside the dust collection box 21. The cleaning mechanism includes two brush plates 23 distributed around the front and rear of the cleaning arc 20. The two brush plates 23 are inclined and fixedly connected to the inner wall of the corresponding dust collection box 21 by telescopic rods 22. A threaded sleeve 24 is fixedly connected to one end of each brush plate 23 near the inner wall of the dust collection box 21. Both ends of the dust collection box 21 are... A threaded rod 25 is rotatably connected through the ash collection box 21. The threaded rod 25 is threadedly connected to the corresponding threaded sleeve 24. A rotating block 26 is fixedly sleeved at one end of the threaded rod 25 outside the ash collection box 21. The two brush plates 23 are inclined at the same angle as the flexible filter screen 14. Then, by simply rotating the rotating block 26, the brush plates 23 can be moved so that they can fit and contact the flexible filter screen 14. When the flexible filter screen 14 is rotating, the dust and impurities attached to its surface are effectively brushed off and concentrated into the ash collection box 21.

[0027] Specifically, the connecting pipe 4 on the same side of the filter unit box located in the middle of the filter box 2 is in the open state. When the centrifuge is working, air can be introduced through the connecting pipe 4 and the filter unit box. A negative pressure environment is formed at the air intake arc 5 to effectively draw in air. The air is filtered by the flexible filter screen 14. During the filtration process, the flexible filter screen 14 rotates left and right by the drive motor 18 and the transmission structure, causing the dust on the surface of the flexible filter screen 14 to rotate to the dust removal arc 20 and be brushed off by the brush plate 23, thus maintaining a clean state. It then rotates back to the air intake arc 5 to continue the filtration work, which greatly improves the service life of the flexible filter screen 14.

[0028] One end of the dust receiving box 21 is sealed and slidably inserted with a pull-out box 27. The pull-out box 27 can be filled with an appropriate amount of water so that the dust can be dissolved in the water after being brushed off, making it convenient for subsequent processing.

[0029] Two insert blocks 28 are fixedly inserted into the two box plates 6 near the two connecting ports 3. An oil injection pipe 29 is inserted into the insert block 28. The end of the oil injection pipe 29 inside the filter unit box is set towards the second gear 9. The end of the oil injection pipe 29 outside the filter unit box is connected to the oil injection valve port. Both ends of the filter box 2 have inserts that correspond to the insert blocks 28. Both inserts have sealing covers 30 on the outside. The sealing covers 30 are rotatably connected to the outer wall of the filter box 2 through a torsion spring shaft. Specifically, after a filter unit box has been used for a certain period of time, it needs to be maintained. At this time, simply use the electric telescopic rod 16 to alternate the filter unit boxes in the center of the filter box 2, so that the filter unit box that needs maintenance is moved to the same side. At this time, the plug 28 on the filter unit box can pass through the corresponding plug and push open the sealing cover 30 to expose the oil injection valve port. At this time, the staff can use lubricating oil spray to inject lubricating oil through the oil injection valve port, so that the lubricating oil is sprayed onto the second gear 9. Since the drive motor 18 drives the two transmission structures to rotate simultaneously through the transmission rod 17, the lubricating oil on the second gear 9 can be effectively transferred to the transmission chain 10 and the first gear 7, thus easily completing the maintenance work.

[0030] This invention provides a pre-filter assembly for centrifugal fans. Through innovative mechanical structure and automated design, it effectively solves the shortcomings of traditional filter assemblies in terms of filtration efficiency, ease of maintenance, and durability. The assembly uses a cam-shaped filter box 2 with two movable filter unit boxes inside. Each filter unit box is equipped with a rotating flexible filter screen. The continuous rotation of the filter screen is achieved through a drive motor 18 and a transmission structure, preventing dust accumulation and significantly improving filtration efficiency and filter screen lifespan. The coordinated design of the cleaning arc 20 and brush plate 23 enables automatic cleaning of the filter screen during operation. Dust is collected through the dust collection box 21 and can be easily cleaned through the pull-out box 27, reducing maintenance frequency and downtime.

[0031] Furthermore, the design of the electric telescopic rod 16 allows the two filter unit boxes to work alternately, ensuring that one set of filters can continue to operate normally while the other is being maintained, thus improving the continuous working capacity of the equipment. The optimized structure of the insert block 28 and the oil injection pipe 29 eliminates the need for component disassembly for lubrication maintenance, further simplifying the maintenance process and reducing operating costs. The modular design not only facilitates installation and replacement but also enhances the adaptability and market competitiveness of the components.

[0032] In summary, this invention combines the advantages of high-efficiency filtration, automatic cleaning, convenient maintenance, and long service life, making it particularly suitable for centrifugal fan systems in high-dust environments. It has significant practical value and broad market prospects.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pre-filter assembly for a centrifugal fan, comprising a filter box (2) with a cam-shaped cross-section, characterized in that, The filter box (2) has a connecting port (3) at both ends and at the center of the top. Both connecting ports (3) are connected to a connecting pipe (4). The ends of the two connecting pipes (4) away from the connecting ports (3) are connected to an installation pipe (1). The installation pipe (1) is connected to the flange of the centrifugal fan inlet. An air inlet (5) is provided at the center of the upper end of the filter box (2). A movable filter mechanism is provided inside the filter box (2). The movable filter mechanism includes two filter unit boxes arranged on the left and right sides. The two filter unit boxes are fixedly connected by a fixing rod. The filter unit box includes two box plates (6) arranged on the left and right sides. The box plates (6) are cam-shaped and are slidably sealed to the inner wall of the filter box (2). A transmission structure is provided between the two corresponding box plates (6). A flexible filter screen (14) is installed on the transmission structure. An electric telescopic rod (16) is fixedly installed on the left end of the filter box (2). The telescopic end of the electric telescopic rod (16) extends into the filter box (2) and is fixedly connected to the filter unit box on the left side. A dust removal arc (20) is opened at the center of the lower end of the filter box (2). A dust collection box (21) communicating with the dust removal arc (20) is fixedly connected to the lower end of the filter box (2).

2. The pre-filter assembly for a centrifugal fan according to claim 1, characterized in that, The transmission structure includes a first gear (7) and a transmission tube (8) rotatably connected between two box plates (6). The first gear (7) is coaxially arranged with the upper center of the box plate (6), and the transmission tube (8) is coaxially arranged with the lower center of the box plate (6). The inner hole of the transmission tube (8) is a regular hexagonal structure. A second gear (9) is fixedly sleeved on the transmission tube (8). A transmission chain (10) is sleeved on both the first gear (7) and the second gear (9). A sliding groove (11) with the same shape is opened on the opposite side of the two box plates (6). A rubber slide strip (12) is sealed and slidably connected in both of the two sliding grooves (11). A plurality of evenly distributed connecting crossbars (13) are fixedly connected between the two rubber slide strips (12). Each connecting crossbar (13) is movably connected to the transmission chain through a connector. The flexible filter screen (14) is fixedly connected to each connecting crossbar (13).

3. A pre-filter assembly for a centrifugal fan according to claim 1, characterized in that, Air outlets (15) are provided on the two box plates (6) near the two connecting ports (3). A transmission rod (17) is rotatably connected between the two inner walls of the filter box (2). The transmission rod (17) has a regular hexagonal cross section. The transmission rod (17) passes through two transmission pipes (8) and is slidably connected to them. A drive motor (18) for driving the transmission rod (17) to rotate is fixedly installed on the outside of the filter box (2).

4. A pre-filter assembly for a centrifugal fan according to claim 1, characterized in that, A sealing disc (19) matching the inner diameter of the connecting pipe (4) is fixedly connected to each of the two box plates (6) near the two connecting ports (3).

5. A pre-filter assembly for a centrifugal fan according to claim 1, characterized in that, The ash receiving box (21) is equipped with a cleaning mechanism, which includes two brush plates (23) distributed in front and behind the ash cleaning arc (20). The two brush plates (23) are inclined and are fixedly connected to the inner wall of the corresponding ash receiving box (21) with telescopic rods (22). The ends of the two brush plates (23) near the inner wall of the ash receiving box (21) are fixedly connected with threaded sleeves (24). The front and rear ends of the ash receiving box (21) are connected with threaded rods (25) that pass through and rotate. The threaded rods (25) are threadedly connected to the corresponding threaded sleeves (24). The end of the threaded rods (25) located outside the ash receiving box (21) is fixedly sleeved with a swivel block (26).

6. A pre-filter assembly for a centrifugal fan according to claim 5, characterized in that, One end of the ash receiving box (21) is sealed and slidably inserted with a pull-out box (27).

7. A pre-filter assembly for a centrifugal fan according to claim 1, characterized in that, Insert blocks (28) are fixedly inserted through the two box plates (6) near the two connecting ports (3). An oil injection pipe (29) is inserted through the insert block (28). One end of the oil injection pipe (29) inside the filter unit box is set towards the second gear (9). The other end of the oil injection pipe (29) outside the filter unit box is connected to the oil injection valve port.

8. A pre-filter assembly for a centrifugal fan according to claim 7, characterized in that, The filter box (2) has sockets at both the left and right ends that correspond to the plug (28). Both sockets are provided with sealing covers (30) on the outside. The sealing covers (30) are rotatably connected to the outer wall of the filter box (2) via a torsion spring shaft.

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