A flat gauze metal filter element and a processing method thereof

Abstract

A planar mesh metal filter element and its processing method are disclosed. The planar mesh metal filter element includes a support tube, two end caps, an elongated connecting piece, and a filter screen. The support tube is a spiral tube. During processing, the elongated connecting piece is first attached and fixed to the outer surface of the support tube, and then welded to the end caps at both ends, thus forming a continuous straight weld line on the support tube connecting the two end caps. This provides a foundation for welding the filter screen. Finally, the filter screen is fixedly wrapped around the support tube by resistance welding to the elongated connecting piece and the end caps. Using this method, the spiral tube can be used in planar mesh metal filter elements, replacing conventional straight seam tubes. Compared to conventional straight seam tubes, the spiral tube not only has higher strength and compressive strength but is also more conducive to mass production, improving production efficiency and reducing production costs.

Description

Technical Field

[0001] This invention relates to the field of filter material processing technology, specifically to a planar mesh metal filter element and its processing method. Background Technology

[0002] Metal filter elements typically refer to filter elements made of metal, such as stainless steel filter elements. Common metal filter elements usually include pleated filter elements and flat filter elements.

[0003] Both flat and pleated filter cartridges include a support tube and a stainless steel filter screen covering the outside of the support tube. The main difference between the two is the shape of the filter screen.

[0004] If the filter screen of a pleated filter element is pleated, during production, the filter screen needs to be folded into pleats by a pleating machine first, then the two ends of the filter screen are welded and fixed, and finally the formed filter screen is put on the outside of the support tube.

[0005] The filter screen of a planar filter element is planar in shape. During production, the filter screen is directly wrapped around the support tube. After the two ends of the filter screen overlap, the filter screen and the support tube are welded together by resistance welding.

[0006] Support pipes mainly serve to support and guide flow. Currently, the commonly used support pipes are usually straight seam pipes and spiral pipes. Compared with straight seam pipes, spiral pipes have significant advantages in terms of strength, production flexibility, and pressure resistance, and are more suitable for mass production.

[0007] However, currently, spiral tubes are typically only used in pleated filter elements, while planar filter elements often use straight seam tubes as internal support tubes. The main reason for this is that spiral tubes are steel pipes made by spirally rolling and welding steel strips. Their weld seams are spiral-shaped, and due to the numerous guide holes on their surface, a continuous straight weld bead cannot be formed on the outer surface of the spiral tube. This prevents continuous resistance welding between the spiral tube and the filter screen, making it unsuitable for planar filter elements. Straight seam tubes, on the other hand, are formed by rolling and welding perforated plates. Their weld seams are straight, and there are no holes at the weld joint. The straight seam weld structure creates a continuous straight weld bead, which can perfectly cooperate with the filter screen for resistance welding. Therefore, currently, all internal support tubes for planar filter elements use straight seam tubes.

[0008] Currently, cost reduction and efficiency improvement are among the main goals of filter manufacturers. Therefore, how to reduce production costs, improve production efficiency, and increase production capacity are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0009] To overcome the shortcomings of the prior art, the present invention provides a planar mesh metal filter element and its processing method.

[0010] The technical solution adopted in this invention is: a planar mesh metal filter element, comprising a skeleton and a filter screen covering the skeleton.

[0011] The frame includes a support tube, end caps, and elongated connecting pieces. The support tube is a spiral tube with several evenly distributed guide holes on its surface. The two end caps are fixedly welded to the upper and lower ends of the support tube, respectively. The elongated connecting pieces are made of stainless steel sheets with a width of 5-7 mm and a thickness of 0.15 mm-0.2 mm, and are fixedly attached to the outer surface of the support tube. The two ends of the elongated connecting pieces are welded to the two end caps, respectively.

[0012] The filter screen covers the outside of the support tube. The two ends of the filter screen overlap and are welded to the elongated connecting piece. The upper and lower ends of the filter screen are respectively welded to the outer walls of the two end caps.

[0013] The processing method of the above-mentioned planar mesh metal filter element includes the following steps: Step 1: Fit and fix the elongated connecting piece to the outer surface of the support tube, and keep the two ends of the elongated connecting piece flush with the two ends of the support tube. The elongated connecting piece is locally spot welded to the support tube on both sides. Step 2: Install end caps at both ends of the support tube. The end caps are welded and fixed to the support tube, and the gap between the elongated connecting piece and the end cap is fully welded. Step 3: Grind and polish the welded joint between the elongated connecting piece and the end cap to ensure a smooth connection between the elongated connecting piece and the end cap; Step 4: Wrap the cut filter screen around the support tube. The specific steps are as follows: Step 4.1: Fix the first end of the filter screen to the elongated connecting piece by resistance welding; Step 4.2: Wrap the filter screen around the support tube, with the tail end of the filter screen overlapping the head end, and fix it in place by resistance welding. Step 4.3: Place the filter element in the straight seam rolling station of the resistance welding machine and perform continuous rolling welding along the long connecting piece; Step 4.4: Place the filter element in the circumferential seam rolling station of the resistance welding machine and perform continuous rolling welding around the outer circumference of the end cap. The beneficial effects of this invention are: by attaching elongated connecting pieces to the surface of the spiral tube, a continuous straight weld bead is formed on the outer surface of the spiral tube for continuous welding with the filter screen, thereby enabling the spiral tube to be used in planar mesh metal filter elements. Compared with conventional straight seam tubes, the spiral tube not only has higher strength and compressive strength, but is also more conducive to mass production, which can improve the production efficiency of mass production and reduce production costs. Attached Figure Description

[0014] Figure 1This is a schematic diagram of the structure of a planar mesh metal filter element according to an embodiment of the present invention.

[0015] Figure 2 for Figure 1 Enlarged diagram of point A in the middle.

[0016] Figure 3 This is a schematic diagram of the support tube structure according to an embodiment of the present invention.

[0017] Figure 4 This is a schematic diagram of the structure after an elongated connecting piece is attached to the surface of the support tube in an embodiment of the present invention.

[0018] Figure 5 This is a schematic diagram of the structure after the end caps are installed at both ends of the support tube according to an embodiment of the present invention. Detailed Implementation

[0019] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0020] like Figures 1-3 As shown, a planar mesh metal filter element includes a frame and a filter screen covering the frame. The frame includes a support tube 1, two end caps, and an elongated connecting piece 3.

[0021] The support tube 1 is a spiral tube with several evenly distributed guide holes 11 formed on its surface. A spiral tube refers to a steel tube formed by spirally coiling and welding steel strip. In this embodiment, the support tube 1 is formed by spirally coiling and welding perforated stainless steel strip. Specifically, it can be formed by sequentially punching, coiling, and welding stainless steel strip using specialized equipment. The perforated spiral tube is a conventional technology, and its structure and processing method are existing technologies; therefore, the processing method of the spiral tube will not be described in detail here.

[0022] Spiral pipes have significant advantages over straight seam pipes, specifically as follows: 1. Spiral tubes have higher structural strength and compressive strength.

[0023] Filter cartridge filtration requires pressure to operate. When the filter cartridge becomes clogged, the pressure difference between the upstream and downstream sides of the filter cartridge will gradually increase. Therefore, the support tube, which serves as the internal support, needs to meet certain pressure resistance requirements. However, straight seam tubes have relatively weak pressure resistance, especially for long filter cartridges. When the pressure is too high, there is a risk of them being crushed. In order to meet the high-pressure ring requirements, the conventional approach is to increase the thickness of the straight seam tube or add additional support rings to improve the pressure resistance. However, this often increases the additional cost.

[0024] The weld seams of spiral pipes are distributed in a spiral shape, which can distribute stress more evenly. Compared with straight seam pipes, they have better strength and stronger impact and pressure resistance.

[0025] 2. The production and processing methods of spiral tubes are more flexible.

[0026] Because filter cartridges come in various sizes, standard sizes are typically 5 inches, 10 inches, 20 inches, and 30 inches in length, and 65mm, 84mm, and 120mm in diameter. If straight seam tubes are used, it's often necessary to first prepare perforated plates of different sizes, and then perform processes such as rolling, welding, straightening, and polishing to form the straight seam tube. The perforated plates are formed by punching holes in steel plates; different sizes of perforated plates require different specifications of steel plates, and different punching dies are needed for punching the steel plates.

[0027] Spiral tubes typically only require one type of stainless steel strip to produce spiral tubes of different diameters and lengths. For different diameter requirements, only the helix angle needs to be adjusted using the equipment tooling. For different length requirements, they can simply be cut to the required length. Therefore, for large-scale production operations, spiral tubes are more efficient and less expensive than straight-seam tubes.

[0028] Two end caps 2 are fixedly welded to the upper and lower ends of the support tube 1, respectively. The end caps can be connectors, such as threaded connectors, 226 connectors, etc., or they can be blind plate caps. Different filter elements have different configurations. For ease of description, all connectors and caps are collectively referred to as end caps. In this embodiment, one end cap is actually a 226 connector, while the other end cap is a blind plate cap.

[0029] The end cap 2 is usually precision machined, and its outer surface can be reliably resisted welded to the filter screen. The end cap 2 and the support tube 1 can be connected by argon arc welding at multiple points to achieve a reliable connection.

[0030] The elongated connecting piece 3 is typically made of stainless steel sheet with a width of 5mm-7mm and a thickness of 0.15mm-0.2mm, and its length is the same as that of the support tube 1. Both ends of the elongated connecting piece 3 are welded to two end caps, and the elongated connecting piece 3 is fixedly attached to the outer surface of the support tube 1. The elongated connecting piece 3 can cover the flow guide holes on the surface of the support tube, thereby forming a continuous straight weld bead between the two end caps 2 for reliable resistance welding with the filter screen.

[0031] The processing method for the above-mentioned planar mesh metal filter element specifically includes the following steps: Step 1: Fit the elongated connecting piece 3 to the outer surface of the support tube 1, ensuring that both ends of the elongated connecting piece 3 are flush with both ends of the support tube 1. Specifically, the elongated connecting piece 3 is fixed to the welding surface of the support tube 1 by welding its two sides.

[0032] Step 2: Install end caps 2 at both ends of the support tube 1. The end caps 2 are welded and fixed to the support tube 1, and the gap between the elongated connecting piece 3 and the end cap 2 needs to be fully welded.

[0033] Step 3: Polish the welded joint between the elongated connecting piece 3 and the end cap 2 to ensure a smooth connection between the end cap and the elongated connecting piece.

[0034] Step 4: Wrap the cut filter screen 4 around the support tube 1. The specific steps are as follows: Step 4.1: Fix the first end of the filter screen 4 to the elongated connecting piece 3 by resistance welding; Step 4.2: Wrap the filter screen 4 around the support tube 1, with the tail end of the filter screen 4 overlapping the head end of the filter screen 4, and fix it by resistance welding spot welding; Step 4.3: Place the filter element in the straight seam rolling station of the resistance welding machine and perform continuous rolling welding along the long connecting piece; Step 4.4: Place the filter element in the circumferential seam rolling station of the resistance welding machine and perform continuous rolling welding around the outer circumference of the end cap.

[0035] The above processing method involves attaching elongated connecting pieces to the surface of the spiral tube, which creates a continuous straight weld bead on the outer surface of the spiral tube for continuous welding with the filter screen. This allows the spiral tube to be used in planar mesh metal filter elements. Compared to conventional straight seam tubes, spiral tubes not only have higher strength and compressive strength, but are also more conducive to mass production, improving production efficiency and reducing production costs.

[0036] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0038] Please note to all technical personnel: Although the present invention has been described according to the specific embodiments above, the inventive concept of the present invention is not limited to this invention. Any modifications that utilize the inventive concept will be included within the scope of protection of this patent.

Claims

1. A planar mesh metal filter element, characterized by, include: A support tube (1) has several evenly distributed guide holes (11) formed on its surface, wherein the support tube (1) is a spiral tube; Two end caps (2) are fixedly welded to the upper and lower ends of the support tube (1), respectively; The elongated connecting piece (3) is fixedly attached to the outer surface of the support tube (1), and the two ends of the connecting piece (3) are respectively welded to the two end caps (2); The filter screen (4) is wrapped around the outside of the support tube (1). The two ends of the filter screen (4) overlap and are welded to the elongated connecting piece (3). The upper and lower ends of the filter screen are respectively welded to the outer walls of the two end caps (2).

2. A method of manufacturing a planar mesh metal filter element, characterized by: The planar metal filter element includes a support tube (1), two end caps (2), an elongated connecting piece (3), and a filter screen (4), wherein the support tube (1) is a spiral tube; The processing method for flat mesh metal filter elements includes the following steps: Step 1: Fit the elongated connecting piece (3) to the outer surface of the support tube (1), and keep the two ends of the elongated connecting piece (3) flush with the two ends of the support tube (1); Step 2: Install end caps (2) at both ends of the support tube (1). The end caps (2) are welded and fixed to the support tube (1), and the gap between the elongated connecting piece (3) and the end caps (2) is fully welded. Step 3: Polish the welded joint between the elongated connecting piece (3) and the end cap (2); Step 4: Wrap the cut filter screen around the support tube (1). The first and last ends of the filter screen (4) are overlapped and welded to the elongated connecting piece (3). The upper and lower ends of the filter screen are welded to the outer walls of the two end caps (2) respectively.

3. The method of claim 2, wherein: In step 1, the elongated connecting piece (3) is welded and fixed to the support tube (1) through its two sides.

4. The method of claim 3, wherein: Step 4 uses resistance welding, and the specific steps are as follows: Step 4.1: Fix the first end of the filter screen to the elongated connecting piece by resistance welding; Step 4.2: Wrap the filter screen around the support tube, with the tail end of the filter screen overlapping the head end, and fix it in place by resistance welding. Step 4.3: Place the filter element in the straight seam rolling station of the resistance welding machine and perform continuous rolling welding along the long connecting piece; Step 4.4: Place the filter element in the circumferential seam rolling station of the resistance welding machine and perform continuous rolling welding around the outer circumference of the end cap.

5. The method of claim 1, wherein: The width of the elongated connecting piece (3) is 5-7mm and the thickness is 0.15mm-0.2mm.

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