A self-cleaning air filter

Abstract

The present invention relates to a self-cleaning air filter, comprising a housing (1), a filter element, and a back-blowing device. The filter element is arranged in the housing (1), and the air outlet end of the back-blowing device extends into the filter element. The filter element comprises a main filter element (2) and a conical safety filter element (3), and the conical safety filter element (3) is arranged inside the main filter element (2). Compared with the prior art, the present invention has the advantages of high back-blowing efficiency, good safety, simple structure, and easy disassembly.

Description

Technical Field

[0001] The present invention relates to the technical field of air filters, in particular to a self-cleaning air filter. Background Art

[0002] Air filters are mainly used to filter dust and impurities in the air, providing clean air for the engine to reduce engine wear. For vehicles, construction machinery and other equipment working in high-dust environments, the air filter element often absorbs a lot of dust after a period of use, causing increased resistance. At this time, the end user often removes the main filter element and cleans the dust on the surface of the air filter element by manual reverse blowing. This manual method will generate a lot of dust in the environment, which is harmful to the health of the operator. It is also easy to damage the filter element due to improper operation, thereby damaging the engine. Therefore, there is an increasing demand for self-cleaning air filter systems in the market.

[0003] Utility model patent CN211777761U discloses a self-cleaning air filter, including a shell, a closed air chamber, a main filter element, a safety filter element, a pulse valve, and a controller. The air filter further includes: an electric pumping device and a check valve. The electric pumping device is connected to a vehicle-mounted battery or an engine to power it. The air outlet of the electric pumping device is connected to the closed air chamber through a conduit. A check valve is provided on the conduit connecting the air outlet of the electric pumping device and the sealed air chamber. The check valve has a one-way conduction function, which only allows compressed air to enter the closed air chamber from the pumping device, but does not allow compressed air to flow back from the closed air chamber to the electric pumping device. It can provide a reliable air source for vehicles that have no air source. At the same time, it can accurately control the compression range, backblowing time, and backblowing times of the compressed air for backblowing the filter element, greatly improving the self-cleaning effect and the service life of the filter element. However, the exposed portion of the safety filter element in this utility model extends too far beyond the guide pipe. This can cause a significant amount of backflush gas to re-enter the safety filter element during backflush, rather than flowing outward in the direction of the main filter element, which affects the overall backflush effect. Furthermore, the backflush device and air filter are integrated into the design, making it difficult to determine whether the backflush device is required in other applications. Summary of the Invention

[0004] The purpose of the present invention is to provide a self-cleaning air filter with high back-blowing efficiency, good safety, simple structure and easy disassembly.

[0005] The objectives of the present invention can be achieved through the following technical solution: a self-cleaning air filter comprising a housing, a filter element, and a backflush device, wherein the filter element is disposed within the housing, and the air outlet of the backflush device extends into the filter element. The filter element comprises a main filter element and a conical safety filter element, wherein the conical safety filter element is disposed within the main filter element. The conical structure facilitates installation, removal, and maintenance of the conical safety filter element. During normal operation, the conical safety filter element forms an angle with the airflow entering the main filter element, thereby reducing the air intake resistance of the safety filter element and allowing the gas filtered by the main filter element to efficiently pass through the sidewall of the safety filter element and, after further filtration, flow out through the long-diameter end.

[0006] Furthermore, the main filter element is an annular filter element, and the conical safety filter element has openings at both ends, namely the long diameter end and the short diameter end. The long diameter end is connected to the connecting pipe outside the shell, and the short diameter end is located inside the main filter element.

[0007] The radius ratio of the long diameter end to the short diameter end is 1 to 1.3:1, and the length of the conical safety filter element extending into the main filter element is 30% to 70% of the length of the main filter element, preferably 30% to 60%.

[0008] A trumpet-shaped jet expansion port is provided in the conical safety filter element. The inlet end of the jet expansion port is connected to the air outlet end of the back-blowing device, and the outlet end is located at the short-diameter end of the conical safety filter element.

[0009] The ratio of the inlet and outlet radii of the jet flare is 1:3-5. A sealing gasket is provided at the connection between the inlet of the jet flare and the outlet of the backflush device. The aerodynamically optimized design of the jet flare effectively guides the diffusion of the backflush airflow, increasing the air velocity of the backflush airflow as it strikes the inner surface of the main filter element, thereby enhancing the backflush effect.

[0010] The back-blowing device comprises a pressure gas tank and an air guide pipe connected to the gas outlet end thereof, and the outlet end of the air guide pipe is connected to the interior of the conical safety filter element.

[0011] Furthermore, the pressure gas tank is provided with a pressure regulating valve and an exhaust valve; the air guide pipe is provided with an air release valve.

[0012] The shell is provided with a tangential air inlet, an air outlet, and a dust exhaust port. The tangential air inlet and the air outlet are arranged on both sides of the shell, with their central axes perpendicular to each other. The main filter element and the conical safety filter element are coaxially arranged, and the central axis of the air outlet coincides with the central axes of the main filter element and the conical safety filter element. The opening direction of the dust exhaust port is opposite to that of the tangential air inlet. In view of the fact that a large amount of dust will be deposited inside the shell after the self-cleaning system backflushes, many air filters on the market are equipped with additional dust exhaust devices, and even have restrictions on the layout and installation of the air filter, which greatly increases the system cost and flexibility of use. To address this problem, the self-cleaning air filter described in the present invention adopts a tangential air inlet structure. When this type of air filter is operating normally, a cyclonic airflow is generated inside the shell. Therefore, after each backflush, when the air filter resumes normal operation, the dust that has fallen inside the shell after the backflush can be effectively carried to the dust exhaust port by the cyclonic airflow inside the air filter, and dust removal can be completed without the need for additional dust removal devices.

[0013] The ratio of the inner diameters of the tangential air inlet, the air outlet and the dust exhaust port is 4-6:4-6:1, and a dust exhaust valve is provided on the dust exhaust port.

[0014] The conical safety filter is internally provided with a support frame, which supports and reinforces the conical safety filter and its internal air jet expansion structure. The conical safety filter is clamped in the air outlet and partially extends into the housing, making installation and removal easy.

[0015] The working principle of the self-cleaning air filter of the present invention is as follows:

[0016] Normal working stage: When the air filter is working normally, it filters and collects dust as part of the engine's air intake system.

[0017] Inflating stage: The inflation port of the pressure gas tank is connected to the air compressor end on the vehicle side. The vehicle continuously inflates the pressure gas tank and stops and maintains the pressure after reaching the pressure set by the pressure regulating valve.

[0018] Blowing stage: As the dust holding capacity of the air filter increases, the system resistance gradually rises. When the alarm pressure is reached, indicating that the filter element needs to be cleaned, the engine is shut down or enters the idle state, and the air valve is opened through the control device. The gas inside the pressure gas tank enters the air filter through the air duct and passes through the main filter element, blowing away the dust on the dirty side surface of the main filter element, completing the self-cleaning process.

[0019] Dust discharge stage: The engine re-enters the working state at the rated flow rate, and the tangential rotating airflow inside the air filter brings the dust that falls inside the shell after self-cleaning into the dust discharge valve, and is discharged by the dust discharge valve under normal working conditions.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. The present invention uses a conical safety filter element, which can effectively prevent foreign matter inside the back-blowing air source and external foreign matter from entering the engine when the main filter element is damaged, thereby improving safety. The conical structure is easy to install and disassemble, and can significantly reduce the resistance value generated by the air filter when it is working normally.

[0022] 2. The present invention can effectively guide the diffusion of the back-blowing airflow through the design of the air jet expansion port, increase the air flow rate when the back-blowing airflow blows toward the inner surface of the main filter element, and enhance the back-blowing effect;

[0023] 3. The present invention utilizes the position and structural design of the tangential air inlet, air outlet, and dust outlet. When the air filter is operating normally, a cyclonic airflow is generated within the housing, discharging dust from the housing through the dust outlet. This eliminates the need for additional dust removal devices, resulting in a simpler structure and lower costs.

[0024] 4. The present invention makes the backflush process precisely controllable and improves the backflush efficiency and safety through the design of the pressure gas tank, pressure regulating valve, exhaust valve and air release valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of the self-cleaning air filter of the present invention;

[0026] In the figure: 1-shell, 11-tangential air inlet, 12-air outlet, 13-dust exhaust port, 131-dust exhaust valve, 2-main filter element, 3-conical safety filter element, 31-long diameter end, 32-short diameter end, 33-jet expansion port, 331-sealing gasket, 34-support frame, 4-connecting pipe, 5-pressure gas tank, 51-pressure regulating valve, 52-exhaust valve, 6-air guide pipe, 61-air release valve. DETAILED DESCRIPTION

[0027] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operating processes, but the protection scope of the present invention is not limited to the following embodiments.

[0028] Example 1

[0029] A self-cleaning air filter, such as Figure 1As shown, the system comprises a housing 1, a main filter element 2, a conical safety filter element 3, a pressure gas tank 5, and an air duct 6. The housing 1 is provided with a tangential air inlet 11, an air outlet 12, and a dust exhaust port 13. The tangential air inlet 11 is located at the top of the housing 1, and the air outlet 12 is located on the side of the housing 1 adjacent to the tangential air inlet 11. The central axes of the tangential air inlet 11 and the air outlet 12 are perpendicular to each other. The dust exhaust port 13 is located at the bottom of the housing 1 and is provided with a dust exhaust valve 131. The annular main filter element 2 is horizontally disposed within the housing 1. The conical safety filter element 3 is fixed within the air outlet 12 and extends into the interior of the main filter element 2. The length of the conical safety filter element 3 extending into the interior of the main filter element 2 is 30% to 70% of the length of the main filter element 2. The pressure gas tank 5 blows backflush gas into the interior of the main filter element 2 through the air duct 6 to clean dust on the outside of the main filter element 2.

[0030] Specifically, the conical safety filter element 3 is open at both ends and supported by a support frame 34. One end of the conical safety filter element 3 is a long-diameter end 31, and the other end is a short-diameter end 32. The long-diameter end 31 connects to the connecting pipe 4 located outside the housing 1, while the short-diameter end 32 is located inside the main filter element 2. The radius ratio of the long-diameter end 31 to the short-diameter end 32 is 1 to 1.3:1. The pressure tank 5 is equipped with a pressure regulating valve 51 and an exhaust valve 52. The air duct 6 is equipped with a bleed valve 61. The outlet end of the air duct 6 extends into the conical safety filter element 131 and is connected to a trumpet-shaped jet flare 33. The inlet end of the jet flare 33 is connected to the air duct 6 and is equipped with a sealing gasket 331 at the connection with the air duct 6. The outlet end of the jet flare 33 is located at the short-diameter end 32 of the conical safety filter element 3. Backflush gas from the pressure tank 5 passes through the air duct 6 and then directly enters the main filter element 2 through the outlet end of the jet flare 33.

[0031] The working principle of the self-cleaning air filter in this embodiment is as follows:

[0032] Normal working stage: When the air filter is working normally, it filters and collects dust as part of the engine's air intake system.

[0033] Inflating stage: The charging port of the pressure gas tank 5 is connected to the air compressor end on the vehicle side. The vehicle continuously inflates the pressure gas tank and stops and maintains the pressure after reaching the pressure set by the pressure regulating valve 51.

[0034] Blowing stage: As the dust holding capacity of the air filter increases, the system resistance gradually rises. When the alarm pressure is reached, indicating that the filter element needs to be cleaned, the engine is shut down or enters the idle state, and the air release valve 61 is opened through the control device. The internal gas of the pressure gas tank 5 enters the air filter through the air guide pipe 6 and passes through the main filter element 2, blowing away the dust on the dirty side surface of the main filter element 2, completing the self-cleaning process.

[0035] Dust discharge stage: The engine re-enters the working state at the rated flow rate, and the tangential rotating airflow inside the air filter brings the dust that falls inside the shell 1 after self-cleaning into the dust discharge valve 131, and is discharged by the dust discharge valve 131 under normal working conditions.

[0036] The above description of the embodiments is intended to facilitate understanding and use by those skilled in the art. Those skilled in the art will readily be able to make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A self-cleaning air filter, comprising a housing (1), a filter element and a back-flushing device, wherein the filter element is arranged in the housing (1), and the air outlet end of the back-flushing device extends into the filter element, characterized in that: The filter element comprises a main filter element (2) and a conical safety filter element (3), wherein the conical safety filter element (3) is arranged inside the main filter element (2); The main filter element (2) is an annular filter element, and the conical safety filter element (3) has two openings at both ends, namely a long diameter end (31) and a short diameter end (32). The long diameter end (31) is connected to the connecting pipe (4) outside the housing (1), and the short diameter end (32) is located inside the main filter element (2); The radius ratio of the long diameter end (31) to the short diameter end (32) is 1 to 1.3:1, and the length of the conical safety filter element (3) extending into the main filter element (2) is 30% to 70% of the length of the main filter element (2); The conical safety filter element (3) is provided with a trumpet-shaped air jet expansion port (33), the inlet end of the air jet expansion port (33) is connected to the air outlet end of the back-blowing device, and the outlet end is located at the short-diameter end (32) of the conical safety filter element (3); The housing (1) is provided with a tangential air inlet (11), an air outlet (12) and a dust exhaust port (13), the tangential air inlet (11) and the air outlet (12) being arranged on both sides of the housing (1), with their central axes being perpendicular to each other; the main filter element (2) and the conical safety filter element (3) are coaxially arranged, and the central axis of the air outlet (12) coincides with the central axes of the main filter element (2) and the conical safety filter element (3); the opening direction of the dust exhaust port (13) is opposite to that of the tangential air inlet (11).

2. The self-cleaning air filter according to claim 1, characterized in that The radius ratio of the inlet end and the outlet end of the jet expansion port (33) is 1:3-5; a sealing gasket (331) is provided at the connection between the inlet end of the jet expansion port (33) and the outlet end of the back-blowing device.

3. The self-cleaning air filter according to claim 1, characterized in that The back-blowing device comprises a pressure gas tank (5) and an air guide pipe (6) connected to the air outlet end thereof, and the outlet end of the air guide pipe (6) is connected to the inside of the conical safety filter element (3).

4. The self-cleaning air filter according to claim 3, characterized in that The pressure gas tank (5) is provided with a pressure regulating valve (51) and an exhaust valve (52); the air guide pipe (6) is provided with an air release valve (61).

5. The self-cleaning air filter according to claim 1, characterized in that The ratio of the inner diameters of the tangential air inlet (11), the air outlet (12) and the dust exhaust port (13) is 4-6:4-6:1, and a dust exhaust valve (131) is provided on the dust exhaust port (13).

6. The self-cleaning air filter according to claim 5, characterized in that A support frame (34) is provided inside the conical safety filter element (3), and the conical safety filter element (3) is clamped in the air outlet (12) and partially extends into the housing (1).

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