A liquid filter cartridge and filtration device

Abstract

This invention discloses a liquid filter element, comprising a filter element and a supporting cylinder. The filter element is tubular, and its shape is a consistent and continuous sine wave on any cross-section of the tubular axis. The filter element has several micropores. The filter element is integrally formed. The supporting cylinder is fitted onto the filter element. This invention, by fabricating the filter element into an annular corrugated tubular shape, can significantly improve the flow-to-volume ratio of the corresponding filter and reduce its volume. By fitting the supporting cylinder onto the entire outer cylinder of the filter element and welding them at the tangent point, the filter element has good structural strength and rigidity. The shape and dimensional error of each corrugation in the filter element can reach the IT11 standard tolerance value. It not only has high pressure differential resistance but also allows for the provision of a backwash suction port on the inlet surface that closely matches the annular sine wave of the filter element, enabling precise control of backwash short circuits. This filter element is used in the water filtration industry and can also be used as a filter element for viscous fluids and mining emulsion filters.

Description

Technical Field

[0001] This invention belongs to the field of fluid filter technology, and specifically relates to a liquid filter element and a filtration device. Background Technology

[0002] Scraper-type self-cleaning filters are high-efficiency, automated filtration devices primarily used for solid-liquid separation of liquid media. Driven by a motor or cylinder, they rotate or reciprocate scrapers or brushes. The scrapers or brushes adhere closely to the inlet liquid surface of the screen plate, scraping off attached impurities, thus achieving continuous filtration and automatic powerful cleaning. Rotary scraper-type self-cleaning filters are the most commonly used type.

[0003] Currently, most scraper-type self-cleaning filters use Johnson screen cylindrical filter elements. These elements are cylindrical tubes made of stainless steel, with continuously arranged wedge-shaped slits formed on their cylindrical surface. These wedge-shaped slits effectively prevent particle clogging while allowing liquid to pass freely. However, because the Johnson screen cylindrical filter element is formed by welding stainless steel wedge wires and support bars together to form a wedge-shaped cylindrical filter surface, the filtration area per unit volume is limited. Since the cross-section of the wedge wires cannot be made very small, typically a minimum of 0.76 mm, to improve the filtration accuracy of the scraper-type self-cleaning filter, the slits must be made smaller, resulting in a lower porosity per unit area and thus a smaller flow-to-volume ratio. This presents significant technical limitations, restricting its application to specific scenarios. Currently, scraper-type self-cleaning filters can only be used when filtration precision is not critical.

[0004] Johnson sieve plates are slit filters, and the so-called filtration accuracy is not an absolute filtration accuracy. In addition, when the filtration accuracy is high, less than 200μm, the ratio of the filtration channel area to the total liquid inlet area of ​​the Johnson sieve plate, i.e., the surface porosity of the filter media, is already very low, resulting in poor economic and technical value. Filter cartridges that achieve or exceed the mechanical strength performance of Johnson sieve plates, have high filtration accuracy, high surface porosity of the filter media, and can be scraped have become an important research topic in this field.

[0005] Chinese patent CN120227710A discloses a detachable and reusable gas filter element and filter. The technical solution includes an inner frame, a filter screen, a support member, and a connector. The inner frame includes an end cap assembly, an inner cylinder, and a connecting plate. The end cap assembly is detachably connected to one end of the inner cylinder, and the inner cylinder has evenly distributed ventilation holes on its circumferential wall. The connecting plate is installed at the other end of the inner cylinder. The filter screen includes a filter screen body and two first end plates. The filter screen body is fitted outside the inner cylinder, and the outer circumferential wall of the filter screen body is folded along the axial or circumferential direction to form a corrugated cross-section with a sawtooth shape. The folding angle of the corrugations is 20° to 40°. The two first end plates are respectively connected to both ends of the filter screen body. The support member is adapted to the shape of the filter screen body and is supported inside the filter screen body. The support member is connected to the inner cylinder or to the first end plates. The connector is used to detachably connect the end cap assembly and one of the first end plates. By folding the outer peripheral wall of the filter body along the axial or circumferential direction to form a serrated corrugated cross-section, the technical problem of increasing the filtration area is solved. However, the above technical solution can only be applied to gas filters. When the serrated corrugated filter is installed in a scraper-type self-cleaning filter, the cleaning brush of the scraper-type self-cleaning filter has difficulty cleaning the corners. In addition, the above technical solution is not integrally formed. When applied to filtering liquids, the liquid pressure is high, which will deform the folded corners of the corrugations, making it impossible for the cleaning brush to clean them. Summary of the Invention

[0006] The purpose of this invention is to provide a liquid filter element and filter element preparation method and filtration device, which has a large filtration area, high filtration accuracy, excellent self-cleaning performance, and longer filter element life, and is particularly suitable for scraper-type self-cleaning filters.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A liquid filter element includes a filter element and a support cylinder.

[0009] The filter element is tubular, and its shape is a consistent and continuous sine wave shape on any cross-section of the tubular axis. The filter element has a number of microfiltration pores. The filter element is integrally formed. The supporting cylinder is sleeved on the filter element, and the supporting cylinder has a number of flow holes.

[0010] Preferably, the inner wall of the supporting cylinder is tangent to the outward protrusion of the sine wave peak of the filter element, and is fixed by welding.

[0011] Preferably, both ends of the filter element are provided with end caps; annular grooves are formed on opposite sides of the two end caps; both ends of the filter element and both ends of the supporting cylinder are inserted into the two annular grooves and fit against the bottom of the annular grooves.

[0012] Preferably, the filter micropores are conical in shape; the end with the smaller diameter of the filter micropores faces the inside of the filter element.

[0013] Preferably, the annular groove formed by the sinusoidal wave of the filter element is a closed annular groove or a spiral annular groove.

[0014] Another aspect of the present invention provides a method for preparing a filter element, comprising the following steps:

[0015] S1. Place the stainless steel strip in a laser drilling device to perform laser drilling. Several micro-pores are obtained on the stainless steel strip to obtain a thin plate-shaped filter plate.

[0016] S2. Roll the thin plate filter into a cylindrical shape and weld the two ends of the filter plate to obtain a cylindrical filter element;

[0017] S3. The cylindrical filter obtained in step S2 is made into a corrugated tube to obtain the filter.

[0018] Preferably, in step S1, the diameter of the filter micropores is 5~500μm.

[0019] Preferably, in step S1, the filter micropores are conical; in step S2, the end with the smaller diameter of the filter micropores on the cylindrical filter element faces the inside of the filter element; the diameter of the end with the smaller diameter of the filter micropores is 5~500μm.

[0020] Preferably, in step S1, the filter micropores are elongated pores; the diameter of the arc surfaces at both ends of the elongated pores is 5~500μm.

[0021] Another aspect of the present invention provides a filtration device, comprising the filter element and the rotary brushing mechanism described above.

[0022] Preferably, the rotary brushing mechanism includes a rotating shaft; the rotating shaft is disposed inside the filter element; at least two connecting rods are fixed on the rotating shaft; a cleaning brush is fixed at the end of the connecting rod away from the rotating shaft; the cleaning brush is adapted to the inner surface of the filter element and is in contact with the inner surface of the filter element.

[0023] This invention manufactures the filter elements in the filter cartridge into annular corrugated tubes, which can more than double the filtration area of ​​a Johnson screen plate of the same size. The corrugations are arranged uniformly along the axial direction of the corrugated tube, forming annular grooves coaxial with the axis of the corrugated tube, facilitating the rotation and scraping of the rotating scraping mechanism. Laser-perforated screen plate cylindrical filter cartridges are easier to manufacture into corrugated tubes, resulting in stable and consistent filtration accuracy.

[0024] The filter element of this invention has a much larger filtration area than the Johnson sieve plate cylindrical filter element with the same nominal diameter, higher filtration accuracy, equally excellent self-cleaning performance, and equally long filter element life, making it particularly suitable for scraper-type self-cleaning filters.

[0025] This invention creates a number of micropores on a filter element using a femtosecond laser drilling method. The micropores have small diameters, high filtration accuracy, and are convenient for filtering smaller solid particles.

[0026] The filter element of this invention is mainly used in the water filtration industry, and can also be used in viscous fluid filter elements and mining emulsion filter elements. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall appearance and structure of the filter element;

[0028] Figure 2 This is a cross-sectional view of the filter element.

[0029] Figure 3 This is a magnified view of a portion of the interior of the filter element;

[0030] Figure 4 This is a schematic diagram of the filter micropore distribution structure;

[0031] Figure 5 This is a schematic diagram of the filter micropore structure in a second specific embodiment of the filter element preparation method;

[0032] Figure 6 This is a schematic diagram of a rotating brush washing structure;

[0033] Figure 7 This is a cross-sectional schematic diagram of the rotating brushing mechanism. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] This type of filter element is used for general fluid filtration; it is more suitable for working conditions with severe fluid media contamination, such as industrial water filter elements, agricultural water filter elements, filter elements for viscous fluids, and filter elements for mining emulsions, etc.

[0036] like Figures 1-3 As shown, the present invention provides a filter element, comprising a filter element 11 and a supporting cylinder 12.

[0037] The filter element 11 is in the shape of an annular corrugated tube. On any cross-section of the tube's axis, the filter element 11 has a consistent, continuous sinusoidal wave shape. The annular groove formed by the sinusoidal wave can be a closed annular groove or a spiral annular groove, wherein the closed annular groove is... Figure 2The annular groove shown is a spiral annular groove in a spiral shape; the filter element 11 has several microfiltration pores, through which the raw water is filtered; the filter element 11 is integrally formed; the supporting cylinder 12 is sleeved on the filter element 11, and the supporting cylinder 12 has several flow holes, the supporting cylinder 12 is coaxial with the filter element 11, wherein the filter element 11 is made of stainless steel with a thickness of 0.2 mm to 1.5 mm;

[0038] During filtration, raw water enters the filter element 11 and passes through the filter element 11 through the filter micropores, becoming purified water. The purified water is discharged from the flow hole. The annular corrugated filter element 11 increases the filtration area and speeds up the filtration process. On the other hand, as the filter element works, impurities in the raw water gradually adhere to the surface of the filter element, thereby reducing the contact area between the raw water and the filter element and greatly reducing the filtration rate. By making the filter element 11 annular, it is easy to install in a scraper-type self-cleaning filter. The cleaning brush brushes off the impurities adhering to the inner surface of the filter element 11, restoring the filtration capacity of the filter element 11 and extending its service life.

[0039] In this embodiment, the inner wall of the supporting cylinder 12 is tangent to the outward protruding sine wave peak of the filter element 11 and is fixed by welding; the outward protruding arc surface of the filter element 11 is welded to the inner wall of the supporting cylinder 12 so that the filter element 11 can be firmly fixed in the supporting cylinder 12.

[0040] In this embodiment, the radii of the outwardly convex arc surface and the inwardly concave arc surface of the filter element 11 are both 5 times the thickness of the filter element 11, so that the corrugated structure of the filter element 11 has a large arc, which makes it easier for the cleaning brush 23 in the filter to clean the inside of the filter element 11.

[0041] More specifically, both ends of the filter element 11 are provided with end caps 13, wherein the end caps 13 are coaxial with the filter element 11; both sides of the two end caps 13 are provided with annular grooves 131; both ends of the filter element 11 and both ends of the supporting cylinder 12 are inserted into the two annular grooves 131 and fit against the bottom of the annular grooves 131. The filter element 11 and the supporting cylinder 12 are fixed by the two end caps 13, which facilitates the disassembly and replacement of the filter element. An annular sealing groove 132 is provided on the outer wall of the end cap 13, and a sealing element is installed in the sealing groove 132. The sealing element is used for sealing the installation of the filter element.

[0042] A first specific embodiment of the method for preparing the filter element 11 of the present invention includes the following steps:

[0043] S1. Place the stainless steel strip in a femtosecond laser drilling device for laser drilling. Several filter micropores are obtained on the stainless steel strip to obtain a thin plate-shaped filter plate.

[0044] Specifically, a femtosecond laser drilling device emits a laser beam onto a stainless steel strip, creating numerous filter micropores on the strip. The stainless steel strip has a thickness between 0.2 mm and 1.5 μm, and the micropore diameter ranges from 5 to 500 μm. Femtosecond lasers are suitable for precision micro-hole processing, have a minimal heat-affected zone, and offer high processing accuracy, making it easy to create multiple filter elements on the stainless steel strip. In this embodiment, for example... Figure 4 As shown, the filter micropores are distributed along an equilateral triangle;

[0045] S2. Roll the thin plate filter into a cylindrical shape and weld the two ends of the filter plate to obtain a cylindrical filter element;

[0046] S3. The cylindrical filter obtained in step S2 is made into a corrugated tube to obtain filter 11.

[0047] Specifically, the cylindrical filter element 11 is placed in a corrugated tube forming machine, which generates intermittent extrusion force on the cylindrical filter element 11. The cylindrical filter element 11 is axially compressed to form corrugations on the cylinder wall. Then, the non-corrugated parts are removed to obtain an annular corrugated tube filter element 11.

[0048] A second specific embodiment of the method for preparing the filter element 11 of the present invention: Unlike the first specific embodiment, as follows... Figure 5 As shown, in step S1, the filter micropores are funnel-shaped; in step S2, the end with the smaller diameter of the filter micropores on the cylindrical filter element faces the inside of the filter element; the diameter of the end with the smaller diameter of the filter micropores is 5~100μm, and the impurity particles in the raw water only contact the edge of the end with the smaller diameter of the filter micropores, reducing the possibility of particles getting stuck in the filter micropores and making the filtration process smoother. In this embodiment, the nominal pore size of the filter micropores is 20μm, and the nominal pore size consistency error of the filter element should be between 75% and 125%. The maximum diameter of the same hole is 25μm, and the minimum diameter is 15μm, which makes it easy to form a filter cake bridge structure.

[0049] A third specific embodiment of the preparation method of filter element 11 of the present invention: Unlike the first and second specific embodiments, in step S1, the filter micropores are elongated holes; the diameter of the arc surfaces at both ends of the elongated holes is 5~100μm. Through the elongated holes, the filter micropores are prevented from being completely blocked by impurity particles in the raw water. When the elongated holes are partially blocked by impurity particles, the filtration accuracy of the filter micropores can be increased.

[0050] like Figure 6 and Figure 7 As shown, a filtration device is provided that is equipped with the aforementioned filter element. This filtration device is a scraper-type self-cleaning filter, comprising a filter element and a rotating brushing mechanism.

[0051] The rotary brushing mechanism includes a rotating shaft 21; the rotating shaft 21 is disposed inside the filter element 11 and is coaxial with the filter element 11; at least two connecting rods are fixed on the rotating shaft 21; a cleaning brush 23 is fixed to one end of the connecting rod away from the rotating shaft 21; the cleaning brush 23 is adapted to and in contact with the inner surface of the filter element 11, wherein the cleaning brush 23 is composed of metal or non-metal filaments, and the cleaning brush 23 is inserted into each corrugated segment 111 of the filter element 11. The rotating shaft 21 is connected to a drive mechanism inside the filter, and the rotating shaft 21 is driven to rotate by the drive mechanism, and the cleaning brush 23 rotates to brush the inner surface of the filter element 11. In addition, the rotating shaft 21 can be a hollow shaft, and the connecting rods can be hollow rods, so as to facilitate the discharge of impurity particles brushed by the cleaning brush 23.

[0052] Specifically, the connecting rod includes a first rod 221 and a second rod 222. A portion of the second rod 222 is inserted into the first rod 221. The second rod 222 can extend and retract. The end of the first rod 221 away from the second rod 222 is fixed to the rotating shaft 21. The end of the second rod 222 away from the first rod 221 is fixed to the cleaning brush 23. A spring 223 is sleeved on the second rod 222. One end of the spring 223 is fixed to the end face of the first rod 221, and the other end is fixed to the cleaning brush 23. The telescopic connecting rod facilitates the cleaning brush 23 to clean the inner surface of the filter element 11, and the spring 223 resets the cleaning brush 23.

Claims

1. A liquid filter element, characterized in that, It includes a filter element (11) and a support cylinder (12). The filter element (11) is tubular, and on any cross section of the tubular axis of the filter element (11), the shape of the filter element (11) is a consistent and continuous sine wave shape; the filter element (11) is provided with a number of filter micropores; the filter element (11) is integrally formed; the support cylinder (12) is sleeved on the filter element (11), and the support cylinder (12) is provided with a number of flow holes.

2. The liquid filter element according to claim 1, characterized in that, The inner wall of the supporting cylinder (12) is tangent to the outward protruding sine wave peak of the filter element (11) and is fixed by welding.

3. The liquid filter element according to claim 1, characterized in that, Both ends of the filter element (11) are provided with end caps (13); both ends of the two end caps (13) are provided with annular grooves (131) on opposite sides; both ends of the filter element (11) and both ends of the supporting cylinder (12) are inserted into the two annular grooves (131) and are in contact with the bottom of the annular grooves (131).

4. The liquid filter element according to claim 1, characterized in that, The filter micropores are conical in shape; the smaller end of the filter micropores faces the inside of the filter element (11).

5. The liquid filter element according to claim 1, characterized in that, The annular groove formed by the filter element (11) in a sinusoidal wave shape is either a closed annular groove or a spiral annular groove.

6. A filtration device, characterized in that, Includes the liquid filter element and rotary brushing mechanism as described in any one of claims 1 to 5.

7. The filtration device according to claim 6, characterized in that, The rotary brushing mechanism includes a rotating shaft (21); the rotating shaft (21) is disposed inside the filter element (11); at least two connecting rods are fixed on the rotating shaft (21); a cleaning brush (23) is fixed at one end of the connecting rod away from the rotating shaft (21); the cleaning brush (23) is adapted to the inner surface of the filter element (11) and is in contact with the inner surface of the filter element (11).

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