High-performance composite filter element and application use thereof

Abstract

A high-performance composite filter element and the use thereof. The composite filter element (5) comprises a filter precision control layer and a support and protection layer, wherein the filter precision control layer is a metal tube (2), and at least part of the metal tube (2) has pores or micropores (4) penetrating through the wall of the metal tube; and the support and protection layer is at least one metal porous mesh (3), and the support and protection layer wraps at least part of the filter precision control layer.

Description

A high-performance composite filter element and its application

[0001] Citation of Related Applications

[0002] This application claims priority and benefits from Chinese patent application No. 202410232014.X filed with the State Intellectual Property Office of the People's Republic of China on February 29, 2024, the entire contents of which are hereby incorporated by reference into the text in their entirety. Technical Field

[0003] The present invention belongs to the field of solid-liquid separation, relates to a filter element and its application, and in particular to a composite filter element for solid-liquid separation and its application. Background Art

[0004] With the development of filtration and separation technology, filter elements need to significantly improve their performance in terms of processing capacity, separation efficiency, filtration accuracy, service life, etc. to meet the use requirements of various filter materials in industrial applications.

[0005] Filtration, often considered the preferred solid-liquid separation technology, has been widely used in chemical processes. Commonly used filter elements include sintered metal, fiber, activated carbon, and microporous ceramic, with sintered metal being the most widely used. Sintered metal wire mesh is typically composed of multiple layers sintered under high temperature and pressure, including a protective layer, a control layer, and a support layer. However, the filtration channels of these filter elements are highly irregular. Once fine particles enter the channels during slurry filtration, irreversible clogging can occur, reducing filtration efficiency, shortening the life of the filter element, and even impacting the stability of the production process.

[0006] CN104857775A discloses a metal powder and metal sintered mesh composite filter element with a circular tubular structure and a production method for the filter element. This patent application obtains a metal mesh layer by vertically cross-stacking two layers of metal wire mesh and then vacuum sintering them. A metal powder suspension is then poured into the metal mesh layer to form a metal powder layer. Finally, the filter element is made into a finished product by sintering, flattening, cutting, forming, and welding. The filter element has the characteristics of a thin filtration control layer and a small flow resistance of the structural support layer, which can improve the filtration stability and online backwash regeneration capability. However, the filter element still has problems such as irregular pore structure, poor anti-fouling and clogging ability, and low filtration accuracy. There are many problems in the actual application process.

[0007] US6068760 discloses a device for separating catalyst and wax inside a slurry bed Fischer-Tropsch synthesis reactor. The filter elements in the device use sintered metal filters from Mott Metallurgical and sintered wire mesh filters from Pall. For fine particles such as submicron particles, the pores of the filter elements are prone to irreversible and permanent blockage.

[0008] Patent applications WO0043098, WO140710A1, CN101391196A and CN101396647B disclose solid-liquid separation filter elements inside a slurry bed Fischer-Tropsch synthesis reactor. All of them use sintered metal filters, and the main difference lies in the spatial layout. Because the thickness of the filter element is larger than the particle size, fine particles entering the channel during slurry filtration are prone to irreversible blockage, affecting the filtration efficiency and shortening the life of the filter element. Frequent replacement of the filter element requires the plant to be shut down, affecting production stability. Summary of the Invention

[0009] To address the shortcomings of the prior art, the present invention provides a high-performance composite filter element and its application, which is resistant to fouling and clogging, exhibits low filtration resistance, high filtration precision, and high filtration efficiency. The high-performance composite filter element of the present invention features a variety of pore sizes, effectively reducing filtration resistance, ensuring filtration precision, and improving filtration throughput. Furthermore, while effectively maintaining the mechanical strength of the filter element, the thickness of the filter element is reduced, thereby avoiding the generation of significant resistance during filtration operations that could affect filtration performance.

[0010] In one aspect, the present invention provides a metal composite filter element comprising a filtration accuracy control layer and a support and protective layer, wherein the filtration accuracy control layer is a metal tube, at least a portion of the metal tube has holes or micropores penetrating the metal tube wall, and the support and protective layer is at least one layer of metal porous mesh, and the support and protective layer wraps at least a portion of the filtration accuracy control layer. Preferably, the metal tube of the filtration accuracy control layer is a hollow cylinder comprising an inner wall and an outer wall. The metal tube has an outer diameter of less than 40 mm, a wall thickness preferably less than about 1.0 mm, and a length of the metal tube of 10-2000 mm. In the present invention, the support and protective layer is composed of two or more layers of metal porous mesh.

[0011] In another aspect, the present invention provides the use of the composite filter element as an inner filter in a slurry bed reactor. Specifically, multiple composite filter elements are arranged vertically symmetrically within the slurry bed reactor. Solids-containing slurry in the slurry bed reactor passes through the composite filter elements to form a filter cake of suitable thickness, thereby retaining the solids in the slurry within the reactor.

[0012] In some embodiments, the filter element of the present invention is particularly suitable for use in a slurry bed reactor for Fischer-Tropsch synthesis.

[0013] The present invention has the following beneficial effects:

[0014] (1) The filtration accuracy control layer in the composite filter element of the present invention is a pore structure that penetrates the metal tube wall, which can efficiently intercept solid particles, has strong anti-fouling and clogging capabilities and low filtration resistance, and improves the filtration flux while effectively ensuring the filtration accuracy.

[0015] (2) The supporting protective layer in the filter element of the present invention is composed of a porous material (metal porous mesh), which can effectively ensure the mechanical strength of the filter element, achieve primary interception of solid particles, and facilitate the formation of filter cakes. After the cakes are formed, they can intercept more particles of various particle sizes, thereby greatly delaying the particles from entering the filtration accuracy control layer.

[0016] (3) The composite filter element of the present invention has the advantages of easy assembly, high mechanical strength, and fatigue resistance. It can withstand frequent filtering backflushing and instantaneous large pressure difference shocks, effectively reducing the maintenance and repair frequency of the filter element during operation and reducing production costs.

[0017] (4) The composite structure of the filter element of the present invention can greatly reduce the weight of the filter element while ensuring the filtering performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic partial side view of a composite filter element according to an embodiment of the present invention. 1 - Filtrate and backflush media channels within the metal tube; 2 - Metal tube serving as the filter precision control layer; 3 - Metal porous mesh wrapped around the outside of the metal tube; 4 - Holes or micropores in the metal tube.

[0019] FIG2 shows a cross-sectional view of a metal tube used for the filter precision control layer.

[0020] Figure 3A shows a schematic diagram of the open area of ​​a metal tube used for a filter precision control layer according to an embodiment of the present application; Figure 3B shows a schematic diagram of the open area and closed area of ​​a metal tube used for a filter precision control layer according to an embodiment of the present invention. L1 is the length of the blank area at both ends of the metal tube; L2 is the length of the open area; L3 is the length of the closed area between the two open areas; and d is the outer wall-to-outer wall diameter of the metal tube.

[0021] Figures 4A-4C show schematic diagrams of the holes or micropores in Figure 1. Figure 4A shows a hole or micropore in the shape of a positive cone with a larger opening diameter δ1 at the outer wall and a smaller opening diameter δ2 at the inner wall; Figure 4B shows a hole or micropore in the shape of an inverted cone with a smaller opening diameter δ2 at the outer wall and a larger opening diameter δ1 at the inner wall; and Figure 4C shows a hole or micropore in which the diameters are all δ.

[0022] Figures 5A-5D show schematic diagrams of a porous metal layer according to an embodiment of the present application. Figure 5A: Schematic diagram of a square hole mesh; Figure 5B: Schematic diagram of a plain dutch mesh; Figure 5C: Schematic diagram of a twill dutch mesh with partial warp coverage; Figure 5D: Schematic diagram of a twill dutch mesh with full warp coverage.

[0023] FIG6 shows a schematic diagram of welding positions on a filter element according to an embodiment of the present application, which includes at least one straight seam and two annular seams.

[0024] 10-Hollow copper tube, 11-Hollow pneumatic chuck, 12-Welding roller, 13-Welding straight seam, 14-Welding circular seam

[0025] The metal tube, serving as the filter precision control layer, is secured at both ends by pneumatic chucks with adjustable clamping force. A porous metal mesh is wrapped around the outside of the tube. An automatic rounding mechanism secures the mesh tightly to the tube, leaving only the axial edges of the mesh overlapping. An automated control program controls the welding rollers to move at a constant speed from one end of the mesh to the other, completing the straight seam weld. Multiple axial straight seam welds can also be completed sequentially.

[0026] The two circumferential seams at both ends of the metal tube wrapped in a porous metal mesh also need to be welded. The pneumatic chuck is controlled to rotate in a circular motion, while the welding roller is fixed and welded along the connection between the porous metal mesh and the metal tube. This completes the welding of one circumferential seam. The welding of the other circumferential seam can then be completed.

[0027] Figure 7 is a schematic diagram of the arrangement of a composite filter element in a slurry bed reactor according to the present application. 5 - composite filter element; 6 - slurry bed reactor; 7 - backflush tank; 8 - filtrate collection tank; 9 - control valve.

[0028] FIG8 is a flow chart of a filtration process using the composite filter element according to the present application.

[0029] Detailed Description of the Invention

[0030] This specification discloses one or more embodiments incorporating the features of the present disclosure. The embodiments disclosed in this application are for illustrative purposes only and are not intended to be limiting. The scope of this application is not limited to the disclosed embodiments, but is limited only by the appended claims.

[0031] The present invention provides a metal composite filter element, which comprises a filtration precision control layer and a support and protective layer, wherein the filtration precision control layer is a metal tube, the support and protective layer is at least one layer of metal porous mesh, and the support and protective layer wraps at least a portion of the filtration precision control layer.

[0032] In the present invention, "filtrate" can be a fluid (liquid or gas, or even a liquid-gas-solid three-phase) that is filtered through a filter element or flows through the filter element to filter fine solid particles (e.g., <1 mm). In some preferred embodiments, the metal composite filter element can be in a circular tubular or flat plate shape. Figure 1 shows a schematic partial side view of a composite filter element according to an embodiment of the present invention.

[0033] In some embodiments, the length of the metal composite filter element may be 10-2000 mm, preferably 50-1700 mm. At least one end of the metal composite filter element described in the present invention has a connection portion connected to the filtration system, and the length is preferably 1-100 mm. For example, a connection portion for flange welding, quick connector connection or threaded connection. In some embodiments, the metal composite filter element has a filtration area wrapped by a supporting protective layer, and optionally at least one closed area. In the present invention, the filtration area is defined as an area of ​​a metal tube with holes or micropores wrapped by a supporting protective layer (so that the liquid can travel through the holes or micropores). The closed area is defined as an un-drilled or closed area on the metal tube. This is because the wall of the metal tube is very thin and its mechanical strength will inevitably decrease after drilling (such as laser drilling), so the continuous drilling area cannot be too long. In some embodiments, the metal composite filter element has more than two filtration areas and at least one closed area. In some preferred embodiments, the metal composite filter element has two, three, four, five, or six or more filtration areas, and closed areas between each filtration area. For example, the metal composite filter element has two filtration zones and a closed zone between the two filtration zones; or the metal composite filter element has three filtration zones and two closed zones between the filtration zones, and so on. In some embodiments, the length of the filtration zone is 1-300 mm, preferably 10-250 mm, for example, 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, 210 mm, 220 mm, 230 mm, 240 mm, 250 mm, 260 mm, 270 mm, 280 mm, 290 mm or 300 mm, or any length within a range consisting of any two of the above lengths.The length of the closed area is 1-50mm, preferably 5-20mm, for example, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm or 50mm, or any length within a range consisting of any two of the above lengths. The length ratio of the filtration zone to the closed zone can be 50:1 or less, preferably 30:1 or less, for example, 50:1, 45:1, 40:1, 35:1, or 30:1, or any ratio within a range consisting of any two of the above ratios. Typically, the closed zone is located between the two filtration zones.

[0034] In the present invention, the filter accuracy control layer can be a hollow cylinder comprising an outer wall and an inner wall, thereby having a wall thickness T between the inner wall and the outer wall. Each metal tube comprises an outer diameter (measured relative to the outer wall) and an inner diameter (measured within and relative to the inner wall) as mentioned in FIG2 . In some embodiments, the metal tube wall thickness T is preferably less than about 1.0 mm. The metal tube has an outer diameter d of less than about 70 mm, more preferably in the range of about 5-30 mm, and even more preferably in the range of about 10-25 mm, for example, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 4mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm, 51mm, 52mm, 53mm, 54mm, 55mm, 56mm, 57mm, 58mm, 59mm, 60mm, 61mm, 62mm, 63mm, 64mm, 65mm, 66mm, 67mm, 68mm, or 69mm, or any diameter within a range consisting of any two of the above numbers. This is because the thickness of the tube should be thin enough to achieve the punching (e.g., laser drilling) operation for forming the filter accuracy control layer as disclosed herein, while still maintaining a certain thickness for sufficient mechanical strength. Therefore, in some preferred embodiments, the metal tube wall thickness is preferably about 0.1-0.7 mm, more preferably about 0.1-0.5 mm, for example, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, or 0.7 mm, or any wall thickness within a range consisting of any two of the foregoing numbers. The thin-walled metal tube wall thickness is sufficiently thin to reduce the cost of drilling holes or micropores and significantly reduce the weight of the filter itself, while still maintaining sufficient mechanical strength of the filter medium.

[0035] Since the mechanical strength of a metal tube (such as a stainless steel thin-walled tube) will inevitably decrease after being punched (such as laser drilling), the continuous punching area cannot be too long. In a preferred embodiment, the metal tube has an open area L2 (as shown in Figure 3A) and an optional closed area L3. In some embodiments, the open area L2 corresponds to the filtration area of ​​the metal composite filter element, and the closed area L3 corresponds to the closed area of ​​the metal composite filter element. For example, the metal tube may have more than two open areas L2 and at least one closed area L3. In a preferred embodiment, the closed area L3 is located between two open areas and provides a connection area for the metal porous mesh supporting the protective layer. In some preferred embodiments, the metal tube has two, three, four, five, or six or more open areas, and closed areas between each open area. For example, the metal tube has two open areas and a closed area located between the two open areas; or, the metal tube has three open areas and two closed areas located between the open areas, and so on. For example, the supporting protective layer can be combined with the filter precision control layer by one or more of welding, winding, weaving or sintering. In some embodiments, the length of the opening area L2 is 1-300 mm, preferably 10-250 mm, for example, 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, 210 mm, 220 mm, 230 mm, 240 mm, 250 mm, 260 mm, 270 mm, 280 mm, 290 mm or 300 mm, or any length within a range consisting of any two of the above lengths. The length of the closed area L3 is 1-50mm, preferably 5-20mm, for example, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm or 50mm, or any length within a range consisting of any two of the above lengths.The ratio of the total length of the open area L2 to the closed area L3 is less than 50:1, preferably 30:1 or less, for example, 50:1, 45:1, 40:1, 35:1, or 30:1, or any ratio within the range consisting of any two of the above ratios.

[0036] In some preferred embodiments, the material of the metal tube of the filtration accuracy control layer may be a stainless steel tube, specifically one of 201, 202, 301, 321, 303, 314, 305, 309, 304, 304L, 317, 316Si, 316, 316L, 309S, and SUS310S, preferably one of 321, 304, 304L, 316, and 316L.

[0037] In some preferred embodiments, as shown in FIG3B , the metal tube may further include an unperforated area L1 at at least one end, which is mainly used to connect other components in the form of welding, ferrules, quick connectors, etc., and the length is preferably 1-100 mm, for example, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, 51 mm, 52 mm, 53 mm, 54 mm, 55 mm, 56 mm, 57 mm, 58 mm, 59 mm, 60 mm, 61 mm, 62 mm, 63 mm, 64 mm, 65 mm, 66 mm, 67 mm, 68 mm, 69 mm, 89mm, 90mm, 91mm, 92mm, 93mm, 94mm, 95mm, 96mm, 97mm, 98mm, 99mm or 100mm, or any length within a range consisting of any two of the above lengths. For example, in some embodiments, the metal tube includes an area L1 located at at least one of its two ends, that is, its surface is not laser drilled, and the length is preferably 1-100 mm; one or more open areas L2, preferably 1-300 mm in length; and an optional closed area L3, preferably 1-50 mm in length; d is the diameter from the outer wall to the outer wall of the metal thin-walled tube, that is, the outer diameter.

[0038] A large number of holes or micropores in the precision control layer are precision-drilled simultaneously or individually in the stainless steel thin-walled tube using high-power laser drilling equipment. In some embodiments, the metal tube can be formed from a tubular or flat sheet metal portion having the laser-drilled holes or micropores therein. The design, arrangement, and configuration of the micropores or pores in the metal tube are not limited.

[0039] In some embodiments, the micropores or holes of the metal tube can be arranged in a certain pattern or array relative to each other. Figure 3A shows an example of a tube with holes or micropores, which are located parallel to each other on the tube wall. In another embodiment, the micropores or holes can be arranged in a substantially straight pattern relative to each other. For example, the micropores or holes are evenly distributed in a certain space in a straight line or rectangular format, wherein the distance between the holes on the warp or weft is equal. That is to say, the design of Figure 3A is an example of a hole arrangement for a metal tube according to an embodiment. In the present invention, the arrangement of the micropores or holes can be, for example, a straight line or rectangular format, a relatively triangular pattern, or a Pocard dot pattern.

[0040] Metal tubes can be manufactured by providing generally round or circular holes or micro-holes drilled into a thin sheet of metal (either individually or using a controlled technique, preferably laser drilling, which allows for multiple holes to be drilled simultaneously), which can be formed into a tube. In another embodiment, the micro-holes or holes can be drilled directly into the tube by a laser. Those skilled in the art of laser drilling will be able to configure laser drilling equipment using the guidance provided herein to configure the micro-holes or holes in any suitable manner.

[0041] Regardless of the size, shape, configuration and / or arrangement of the micropores or holes in the metal tube, according to an embodiment, the micropores or holes illustratively shown herein have a thickness T extending through the wall of the metal tube 4, including holes or holes of other sizes, shapes, configurations and / or arrangements not explicitly described.

[0042] In some preferred embodiments, the metal tube pore shape of the filtration accuracy control layer is one or more of a circular hole and a strip hole.

[0043] The micropores or holes can have any size, shape, configuration and / or arrangement. For example, they can be processed into a shape with uniform size from outer wall to outer wall and a diameter of δ; they can also be processed into a positive cone shape with a larger opening diameter δ1 at the outer wall and a smaller opening diameter δ2 at the inner wall; they can also be processed into an inverted cone shape with a smaller opening diameter δ2 at the outer wall and a larger opening diameter δ1 at the inner wall. Figures 4A-4C show detailed views of holes or micropores according to embodiments of the present application. Among them, Figure 4A shows a positive cone shape with a larger opening diameter δ1 at the outer wall and a smaller opening diameter δ2 at the inner wall; Figure 4B shows an inverted cone shape with a smaller opening diameter δ2 at the outer wall and a larger opening diameter δ1 at the inner wall; Figure 4C shows a shape with a diameter of δ.

[0044] For example, the size of the pores or micropores is determined by the actual particle size of the solid particles to be filtered. In the composite filter element of the present invention, the dimensions (including δ1, δ2, and δ) can all be in the range of 0.0001-0.1 mm, for example, 0.001-0.1 mm. For example, δ can be in the range of 0.001-0.1 mm. The diameter δ1 can be in the range of 0.001-0.1 mm, and the diameter δ2 can be in the range of 0.0005 mm-0.08 mm.

[0045] In the above three cases, the filter opening diameter in the third case is δ, and its taper angle is 0. The taper angle of the filter element in the first two cases can be calculated according to the following formula:

[0046] tan(taper angle / 2)=(larger opening diameter δ1-smaller opening diameter δ2) / (2*wall thickness T)

[0047] In the case of a tapered hole, the taper angle of the hole or microhole is preferably 0° to 10°.

[0048] In a preferred embodiment, the holes or micropores on the metal tube are uniformly and symmetrically distributed around its surface for filtering solid particles from a fluid. In a preferred embodiment, at least one of the shape, diameter, and orientation of the holes or micropores on the metal tube is consistent. For example, in the case of tapered holes, preferably all larger openings are located on the outer wall. Furthermore, preferably, the taper angle of the holes or micropores is consistent.

[0049] In some further preferred embodiments, the metal tube of the filter precision control layer has a porosity of 1-60%, for example, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, or 60%, or any ratio within a range comprised of the foregoing. The porosity of the pores or micropores can be the percentage of the pore opening area based on the total surface area of ​​the open area. For example, in the case of tapered pores, the porosity is calculated based on the area in the direction with the largest opening.

[0050] In some preferred embodiments, the supporting protective layer is composed of one or more layers of a porous material, preferably sintered metal mesh, such as sintered metal mesh, sintered metal powder, metal fiber membrane, or sintered metal felt. This layer ensures the mechanical strength of the filter element, provides primary interception of solid particles, facilitates filter cake formation, and prevents large solid particles from entering the through-hole filter precision control layer.

[0051] The metal porous layer is wrapped around the stainless steel thin-walled tube, and plays the role of intercepting solid particles layer by layer and supporting the protective layer.

[0052] Sintered wire mesh is categorized into square mesh and dense mesh based on the density of the wire mesh. When square mesh is used as a filter medium, particles larger than the mesh size settle on the surface of the mesh, thus providing surface filtration. Dense mesh can be further divided into plain and twill weaves, while twill weaves can be woven with either partial or full warp coverage. When dense mesh is used as a filter medium, particles enter the center of the mesh and are retained by internal flow channels smaller than the particle size. Compared to square mesh, it provides deep filtration.

[0053] In some embodiments, the supporting protective layer may be composed of one or more layers of sintered metal mesh (e.g., square mesh and dense mesh), sintered metal powder, metal fiber film, or sintered metal felt. For example, the supporting protective layer may be composed of one, two, three, four, or more layers of sintered metal mesh (e.g., square mesh and dense mesh), sintered metal powder, metal fiber film, or sintered metal felt.

[0054] In some embodiments, the pore size of all layers in the supporting and protective layer is larger or smaller than the pore size of the filtration precision control layer. For example, in the case of a tapered pore, the pore size of all layers in the supporting and protective layer is larger or smaller than the larger pore size δ1 in the filtration precision control layer. In the case of a tapered pore, the pore size of all layers in the supporting and protective layer is larger than the larger pore size δ1 in the filtration precision control layer; alternatively, in the case of a tapered pore, the pore size of all layers in the supporting and protective layer is smaller than the smaller pore size δ2 in the filtration precision control layer.

[0055] In the case of multiple layers in the supporting and protective layer, the pore diameters may be the same or different. In a preferred embodiment, the pore diameters are the same in the multiple layers of the supporting and protective layer. Alternatively, in some embodiments, the pore diameters of the multiple layers of the supporting and protective layer increase or decrease layer by layer, for example, the pore diameter of the outermost layer is the largest and gradually decreases toward the inner layer.

[0056] In some preferred embodiments, the supporting and protective layer has a total thickness of 0.01-1 mm, a pore size of 1-200 mesh, and a porosity of 1-60%. In some preferred embodiments, when the filtration precision control layer is composited with the supporting and protective layer, a single or multiple supporting and protective layers can be located outside the filtration precision control layer, for example, wrapped around the outer layer of a metal tube.

[0057] In the present invention, porosity refers to the percentage of the pore volume in a porous material to the total volume of the material in a natural state.

[0058] In some preferred embodiments, the filtration accuracy control layer and the supporting protective layer of the present invention may be combined by one or more of welding, winding, weaving or sintering.

[0059] In some further preferred embodiments, the high-performance metal composite filter element described herein, when used in industrial applications, has a nominal diameter of 1-70 mm and a length of 10-2000 mm. Two main connection methods are available: one in which both ends of the filter element are welded or threaded to a flange via a 1-100 mm long joint; the other in which one end of the filter element is welded or threaded to a flange via a 1-100 mm long joint, with the other end sealed with a plug.

[0060] In some preferred embodiments, the high-performance composite filter element described in the present invention can be applied to sewage oil removal filtration, oil slurry filtration, solid-liquid two-phase separation in a reactor, solid-liquid two-phase separation outside a reactor, and gas-liquid-solid three-phase system filtration and separation, and is particularly suitable for solid-liquid two-phase separation in a reactor or gas-liquid-solid three-phase system filtration and separation.

[0061] In one embodiment, the present invention provides the use of the aforementioned filter element as an inner filter in a slurry bed reactor. Specifically, 2-20 composite filter elements are assembled into small groups, and each group of composite filter elements is densely arranged in a vertically geometrically symmetrical manner within the slurry bed reactor. The solid-containing slurry passes through the filter elements to form a filter cake of appropriate thickness, thereby retaining the solids in the slurry within the reactor.

[0062] In some preferred embodiments, the filter elements are arranged in a slurry bed reactor into two layers, wherein each layer may be composed of 1 to 100 groups of composite filter elements.

[0063] In one embodiment, the present invention provides a method for filtering using the above-mentioned composite filter element as an inner filter in a slurry bed reactor, wherein the composite filter element has a filtration cycle, a soaking cycle and a backflushing cycle during filtration, and there is always a portion of the composite filter element group in the filtration cycle, a portion in the soaking cycle, and a portion in the backflushing cycle.

[0064] In some preferred embodiments, the composite filter element group refers to a group consisting of 2-20 composite filter elements.

[0065] In some preferred embodiments, the composite filter element groups can be arranged in two layers within the reactor as needed to facilitate overall filtration process control. For example, each layer can be composed of 1-100 groups of composite filter elements.

[0066] In some preferred embodiments, the filtration cycle refers to a process in which the filtrate is continuously removed from the slurry bed reactor through the filter pores of the composite filter element and flows into the filtrate collection tank through the regulating valve.

[0067] In some further preferred embodiments, the filtration pressure difference during the filtration cycle is 1-1000 KPa, preferably 5-100 KPa; the filtration time is 5-200 min, preferably 10-100 min.

[0068] In some preferred embodiments, the soaking cycle refers to soaking the composite filter element group whose surface has been wrapped by the filter cake and whose filter pores have been blocked in the slurry bed reactor, and using the turbulent slurry to flush the filter cake, wherein the soaking cycle time is 1-20 minutes, preferably 2-10 minutes.

[0069] In some preferred embodiments, the backflushing cycle refers to removing the filter cake by backflushing to regenerate the filter element. Specifically, the pressurized backflushing medium quickly penetrates the micropores of the filter element and instantly explodes to blow away the filter cake. The backflushing direction is opposite to the filtering direction.

[0070] In some further preferred embodiments, the backflushing cycle conditions can be flexibly adjusted according to the degree of fouling of the filter element. Specifically, the duration of a single backflushing is 1-20s, preferably 3-10s; the backflushing medium pressure is 1-1000KPa, preferably 10-500KPa; the backflushing medium temperature is 100-300°C, preferably 150-200°C; and the number of backflushing times is 1-10 times, preferably 3-6 times.

[0071] In some further preferred embodiments, the backflushing medium is a gas or liquid, specifically fresh reaction gas, recycled reaction gas, inert gas, or clean filtrate obtained by filtration. The backflushing medium is preferably selected so as not to contaminate the system to be separated.

[0072] In some preferred embodiments, the backflushing method can be pure gas backflushing regeneration, pure liquid backflushing regeneration, or a combination of gas backflushing and liquid backflushing.

[0073] In some preferred embodiments, during the backflushing cycle, the backflushing medium can be backflushed from the top of the vertically arranged composite filter element or from the bottom of the vertically arranged composite filter element. Preferably, the backflushing medium is backflushed alternately from the top and bottom of the composite filter element.

[0074] The exemplary technical solutions of the present invention can be described in the following numbered paragraphs, but the scope of protection of the present invention is not limited thereto:

[0075] 1. A metal composite filter element, comprising a filtration precision control layer and a support and protective layer, wherein the filtration precision control layer is a metal tube, the support and protective layer is at least one layer of metal porous mesh, and the support and protective layer wraps at least a portion of the filtration precision control layer.

[0076] 2. The metal composite filter element according to paragraph 1, wherein the length of the metal composite filter element is 10-2000 mm.

[0077] 3. The metal composite filter element according to paragraph 2, wherein the length of the metal composite filter element is 50-1700 mm.

[0078] 4. The metal composite filter element according to paragraph 1, wherein at least one end of the metal composite filter element has a connection portion for connecting to a filter system, the length of the connection portion being 1-100 mm.

[0079] 5. The metal composite filter element according to paragraph 4, wherein the connection portion is a connection portion for flange welding, quick connector connection, or threaded connection.

[0080] 6. The metal composite filter element according to any one of paragraphs 1 to 5, wherein the metal composite filter element comprises a filtration zone surrounded by a supporting protective layer, and optionally at least one closed zone.

[0081] 7. The metal composite filter element according to paragraph 6, wherein the metal composite filter element has two or more filtration zones and at least one closed zone.

[0082] 8. The metal composite filter element of paragraph 6, wherein the metal composite filter element has two, three, four, five, or six or more filtration zones and closed zones between the filtration zones.

[0083] 9. The metal composite filter element according to paragraph 6, wherein the length of the filtration zone is 1-300 mm, or 10-250 mm.

[0084] 10. The metal composite filter element according to paragraph 6, wherein the length of the closed area is 1-50 mm, or 5-20 mm.

[0085] 11. The metal composite filter element according to paragraph 6, wherein the length ratio of the filtration area to the closed area is 50:1 or less, or 30:1 or less.

[0086] 12. The metal composite filter element according to any one of paragraphs 1 to 5, wherein, in the present invention, the filtration accuracy control layer is a hollow cylinder comprising an outer wall, an inner wall, and a wall thickness T.

[0087] 13. The metal composite filter element of paragraph 12, wherein the wall thickness T is less than 1.0 mm, or is 0.1-0.7 mm, or 0.1-0.5 mm.

[0088] 14. The metal composite filter element of any of paragraphs 1-5, wherein the metal tube has an outer diameter d of less than 70 mm, or an outer diameter d in the range of 5-30 mm, or an outer diameter d of between about 10-25 mm.

[0089] 15. The metal composite filter element according to any of paragraphs 1-5, wherein the metal tube has an open area L2 and an optional closed area L3.

[0090] 16. The metal composite filter element according to paragraph 15, wherein the metal tube has two or more open areas L2 and at least one closed area L3.

[0091] 17. The metal composite filter element of paragraph 15, wherein the metal tube has two, three, four, five, or six or more open areas and closed areas between the open areas.

[0092] 18. The metal composite filter element according to paragraph 15, wherein the length of the open area L2 is 1-300 mm, or 10-250 mm.

[0093] 19. The metal composite filter element according to paragraph 15, wherein the length of the closed area L3 is 1-50 mm, or 5-20 mm.

[0094] 20. The metal composite filter element according to paragraph 15, wherein the ratio of the total length of the open area L2 to the closed area L3 is 50:1 or less, or 30:1 or less.

[0095] 21. The metal composite filter element according to paragraph 15, wherein the metal tube of the filtration accuracy control layer is made of a stainless steel tube.

[0096] 22. The metal composite filter element according to paragraph 21, wherein the stainless steel tube is one of 201, 202, 301, 321, 303, 314, 305, 309, 304, 304L, 317, 316Si, 316, 316L, 309S, and SUS310S.

[0097] 23. The metal composite filter element according to paragraph 22, wherein the stainless steel tube is one of 321, 304, 304L, 316, and 316L.

[0098] 24. The metal composite filter element according to any of paragraphs 1-5, wherein the metal tube further includes a non-perforated area L1 at at least one end, with a length of 1-100 mm.

[0099] 25. The metal composite filter element according to any one of paragraphs 1 to 5, wherein the metal tube pores of the filtration accuracy control layer are in the shape of one or more of circular holes and strip-shaped holes.

[0100] 26. The metal composite filter element according to paragraph 25, wherein the micropores or holes of the metal tube are uniform in size from the outer wall to the outer wall of the metal tube, and have a diameter of δ; or the micropores or holes of the metal tube are in the shape of a right cone with a larger opening diameter δ1 at the outer wall and a smaller opening diameter δ2 at the inner wall; or the micropores or holes of the metal tube are in the shape of an inverted cone with a smaller opening diameter δ2 at the outer wall and a larger opening diameter δ1 at the inner wall.

[0101] 27. The metal composite filter element of paragraph 25, wherein δ is in the range of 0.001-0.1 mm; diameter δ1 is in the range of 0.001-0.1 mm; or diameter δ2 is in the range of 0.0005-0.08 mm.

[0102] 28. The metal composite filter element according to paragraph 25, wherein the pores or micropores of the precision control layer are precisely drilled on the stainless steel thin-walled tube simultaneously or separately by a high-power laser drilling device.

[0103] 29. The metal composite filter element of paragraph 25, wherein the metal tube is formed from a tubular or flat sheet portion having laser drilled holes or pores therein.

[0104] 30. The metal composite filter element of paragraph 25, wherein the pores or holes are arranged in a linear or rectangular format, in a relatively triangular pattern, or in a Pocard dot pattern.

[0105] 31. The metal composite filter element of paragraph 25, wherein the pores or holes have a thickness T extending through the wall of the metal tube.

[0106] 32. The metal composite filter element according to paragraph 25, wherein, when the pores or micropores are tapered pores, the taper angle of the pores or micropores is 0°-10°.

[0107] 33. The metal composite filter element of paragraph 25, wherein at least one of the shape, diameter, and orientation of the pores or micropores on the metal tube remains consistent.

[0108] 34. The metal composite filter element of paragraph 33, wherein, in the case of tapered holes, all larger openings are located on the outer wall; or, alternatively, the taper angle of the holes or micropores remains consistent.

[0109] 35. The metal composite filter element according to any one of paragraphs 1 to 5, wherein the metal tube in the filtration accuracy control layer has an open porosity of 1 to 60%.

[0110] 36. The metal composite filter element according to any one of paragraphs 1 to 5, wherein the supporting protective layer is composed of one or more layers of sintered metal wire mesh, sintered metal powder, metal fiber membrane, or sintered metal felt.

[0111] 37. The metal composite filter element according to paragraph 36, wherein the supporting protective layer comprises one or more layers of sintered metal mesh.

[0112] 38. The metal composite filter element according to paragraph 36, wherein the supporting protective layer is composed of 1, 2, 3, or 4 or more layers of square mesh or dense mesh sintered metal wire mesh.

[0113] 39. The metal composite filter element according to paragraph 36, wherein the pore size of all layers in the supporting and protective layer is larger than or smaller than the pore size of the filtration accuracy control layer.

[0114] 40. A metal composite filter element according to paragraph 36, wherein, in the case of conical holes, the pore sizes of all layers in the supporting protective layer are larger than the larger pore size δ1 in the filtration accuracy control layer; or, in the case of conical holes, the pore sizes of all layers in the supporting protective layer are smaller than the smaller pore size δ2 in the filtration accuracy control layer.

[0115] 41. The metal composite filter element according to paragraph 36, wherein, in the supporting protective layer, in the case of multiple layers, the pore sizes are the same; or, in the multi-layer supporting protective layer, the pore sizes of the multi-layer pores increase or decrease layer by layer.

[0116] 42. The metal composite filter element according to paragraph 36, wherein the supporting protective layer has a total thickness of 0.01-1 mm, a pore size of 1-200 mesh, and a porosity of 1-60%.

[0117] 43. The metal composite filter element according to any one of paragraphs 1 to 5, wherein the filtration accuracy control layer and the support and protection layer are combined by one or more of welding, winding, weaving or sintering.

[0118] 44. Use of the metal composite filter element according to any of paragraphs 1 to 43 as an inner filter in a slurry bed reactor.

[0119] 45. A method for filtering in a slurry bed reactor using the metal composite filter element according to any one of paragraphs 1 to 43 as an inner filter, wherein the metal composite filter element has a filtration cycle, a soaking cycle and a backflushing cycle during filtration, and there is always a portion of the composite filter element group in the filtration cycle, a portion in the soaking cycle, and a portion in the backflushing cycle.

[0120] 46. ​​The method according to paragraph 45, wherein the filtration pressure difference during the filtration cycle is 1-1000 kPa, or 5-100 kPa; and the filtration time is 5-200 min or 10-100 min.

[0121] Soaking the filter cake in a slurry bed reactor and using the turbulent slurry to flush the filter cake, wherein the soaking cycle time is 1-20 minutes, or 2-10 minutes; or

[0122] The duration of a single backflushing is 1-20s or 3-10s; the pressure of the backflushing medium is 1-1000KPa or 10-500KPa; the temperature of the backflushing medium is 100-300℃ or 150-200℃; the number of backflushing times is 1-10 times or 3-6 times.

[0123] 47. The method according to paragraph 45, wherein the backflushing medium is a gas or a liquid selected from fresh reaction gas, recycled reaction gas, inert gas, or clean filtrate obtained by filtration.

[0124] 48. The method of paragraph 45, wherein the backflushing method is gas backflushing regeneration alone, liquid backflushing regeneration alone, or a combination of gas backflushing and liquid backflushing.

[0125] 49. The method according to paragraph 45, wherein during the backflushing cycle, the backflushing medium is backflushed from the top of the vertically arranged composite filter element; or, backflushed from the bottom of the vertically arranged composite filter element; or, the backflushing medium is alternately backflushed from the top and bottom of the composite filter element.

[0126] Unless otherwise specifically stated, singular terms encompass plural terms and plural terms encompass the singular. Unless otherwise specifically stated, the words "a" or "an" mean "at least one" or "at least one." Unless otherwise specified, the use of "or" means "and / or."

[0127] Herein, unless otherwise specified, the terms "comprise, include and contain" or equivalents are open-ended expressions, meaning that in addition to the listed elements, components and steps, other unspecified elements, components and steps may also be included.

[0128] For the purposes of description and disclosure, all patents, patent applications, and other identified publications are expressly incorporated herein by reference. These publications are provided solely for their disclosure prior to the filing date of the present application. All statements regarding the dates of these documents or the representations of their contents are based on the information available to the applicant and do not constitute any admission as to the correctness of the dates of these documents or the contents of these documents. Furthermore, any citation of these publications herein does not constitute an admission that such publications become part of the common general knowledge in the art in any country. DETAILED DESCRIPTION

[0129] The present invention is described in detail below by way of examples, but is not intended to constitute any adverse restriction to the present invention. The compound of the present invention can be prepared by a variety of synthetic methods well known to those skilled in the art, including the specific embodiments listed below, the embodiments formed by the combination thereof with other chemical synthesis methods and equivalent replacement modes well known to those skilled in the art, and preferred embodiments include but are not limited to the embodiments of the present invention. It will be apparent to those skilled in the art that various changes and improvements will be made to the specific embodiments of the present invention without departing from the spirit and scope of the present invention.

[0130] Next, the present invention will be described in further detail with reference to Examples, but the present invention is not limited to these Examples.

[0131] Preparation Example 1

[0132] The two layers of sintered wire mesh (see table) are pressed and sintered together in a vacuum sintering furnace at temperatures above 1100°C. Then, they are rolled into a cylindrical shape, with the first layer of sintered wire mesh positioned outside the cylinder. The sintered wire mesh cylinder is placed over the laser-perforated tube, with the center edges perfectly aligned or with a 1mm overlap. The sintered wire mesh should completely cover the perforated area of ​​the laser-perforated tube. The process parameters for the laser-perforated tube are shown in Table 2.

[0133] A hollow copper tube with an inner diameter slightly smaller than the laser-perforated tube is inserted into the laser-perforated tube. This tube serves three purposes: 1. It provides support when welding the sintered wire mesh to the laser-perforated tube, preventing damage to the mesh and tube; 2. Copper's improved electrical conductivity facilitates a secure weld between the sintered wire mesh and the laser-perforated tube; and 3. Cooling water or air can be continuously flushed into the tube to dissipate heat generated during welding.

[0134] After the sintered wire mesh is tightly attached to the laser-perforated tube, it is welded using a spot welder or seam welder. The welding positions include at least one straight seam and two circumferential seams, as shown in Figure 6.

[0135] Table 1 Related parameters of the support protective layer of Preparation Example 1

[0136] Table 2 Related parameters of the precision control layer of Preparation Example 1

[0137] Preparation Example 2

[0138] In the same manner as in Preparation Example 1, a filter element was prepared using a support protection layer and a precision control layer having the parameters shown in Tables 3 and 4 below.

[0139] Table 3 Related parameters of the support protective layer of Preparation Example 2

[0140] Table 4 Related parameters of the precision control layer of Preparation Example 2

[0141] Preparation Example 3

[0142] In the same manner as in Preparation Example 1, a filter element was prepared using a support protection layer and a precision control layer having the parameters shown in Tables 5 and 6 below.

[0143] Table 5 Related parameters of the support protective layer of Preparation Example 3

[0144] Table 6 Related parameters of the precision control layer of Preparation Example 3

[0145] Example 1

[0146] In this embodiment, the composite filter element in Preparation Example 1 is used.

[0147] In this embodiment, the composite filter element is used in an industrial Fischer-Tropsch slurry bed reactor. The filter slurry consists of wax and catalyst particles. The wax distillation range analysis results are shown in Table 7.

[0148] Table 7 Wax distillation analysis results

[0149] In this embodiment, the composite filter element sequentially undergoes a filtration cycle, a soaking cycle, and a backflush cycle. During the filtration cycle, particles containing wax and catalyst are removed from the reactor through the composite filter element and flow into the filtrate collection tank, while the catalyst particles are retained. The filtration pressure difference is adjusted to 100 kPa, and the filtration cycle is 60 minutes. The composite filter element, whose surface is covered with filter cake and whose filter pores are clogged, enters a soaking cycle, where it is internally soaked in the Fischer-Tropsch slurry bed reactor for 10 minutes, and the filter cake is flushed with turbulent slurry. Then, it enters a backflush cycle, where the pressurized backflush medium in the backflush tank is introduced into the Fischer-Tropsch slurry bed reactor, rapidly passes through the filter pores of the composite filter element, and instantly explodes to blow away the filter cake. A single backflush lasts 10 seconds, the backflush medium pressure is 500 kPa, the backflush medium temperature is 200°C, and the backflush medium is alternately backflushed from the top and bottom of the composite filter element, with a backflush frequency of 3. The composite filter element that has undergone the backflush cycle can be recycled into the filtration cycle. According to the test, the composite filter element in this embodiment ran stably and without any failure for 8000 hours in the Fischer-Tropsch slurry bed reactor, and the solid particle removal rate reached more than 99%.

[0150] Example 2

[0151] In this embodiment, the composite filter element in Preparation Example 2 is used.

[0152] In this embodiment, the composite filter element is used in an industrial Fischer-Tropsch slurry bed reactor. The filter slurry consists of wax and catalyst particles. The wax distillation range analysis results are shown in Table 8.

[0153] Table 8 Wax distillation analysis results

[0154] In this embodiment, the composite filter element sequentially undergoes a filtration cycle, a soaking cycle, and a backflush cycle. During the filtration cycle, particles containing wax and catalyst are removed from the reactor through the composite filter element and flow into the filtrate collection tank, while the catalyst particles are retained. The filtration pressure difference is adjusted to 50 kPa, and the filtration cycle is 100 minutes. The composite filter element, whose surface is covered with filter cake and whose filter pores are clogged, enters a soaking cycle, where it is internally soaked in the Fischer-Tropsch slurry bed reactor for 5 minutes, and the filter cake is flushed with turbulent slurry. Then, it enters a backflush cycle, where the pressurized backflush medium in the backflush tank is introduced into the Fischer-Tropsch slurry bed reactor, rapidly passes through the filter pores of the composite filter element, and instantly explodes to blow away the filter cake. A single backflush lasts 10 seconds, the backflush medium pressure is 400 kPa, the backflush medium temperature is 200°C, and the backflush medium is alternately backflushed from the top and bottom of the composite filter element, for a total of 6 backflush cycles. The composite filter element that has undergone the backflush cycle can be recycled into the filtration cycle. According to tests, the composite filter element in this embodiment has been running stably and trouble-free in a Fischer-Tropsch slurry bed reactor for half a year, and the solid particle removal rate has reached more than 99%.

[0155] Example 3

[0156] In this embodiment, the composite filter element in Preparation Example 3 was used.

[0157] In this embodiment, the composite filter element is used in an industrial Fischer-Tropsch slurry bed reactor. The filter slurry consists of wax and catalyst particles. The wax distillation range analysis results are shown in Table 9.

[0158] Table 9 Wax distillation analysis results

[0159] In this embodiment, the composite filter element sequentially undergoes a filtration cycle, a soaking cycle, and a backflush cycle. During the filtration cycle, particles containing wax and catalyst are removed from the reactor through the composite filter element and flow into a filtrate collection tank, where the catalyst particles are retained. The filtration pressure differential is adjusted to 10 kPa, and the filtration cycle is 40 minutes. The composite filter element, whose surface is covered with filter cake and whose filter pores are clogged, enters a soaking cycle, where it is internally immersed in the Fischer-Tropsch slurry bed reactor for 2 minutes, where the filter cake is flushed with turbulent slurry. Next, the backflush cycle begins, where pressurized backflush media from the backflush tank is introduced into the Fischer-Tropsch slurry bed reactor, rapidly passing through the filter pores of the composite filter element and instantly blasting the filter cake away. A single backflush cycle lasts 5 seconds, with a backflush media pressure of 100 kPa and a backflush media temperature of 150°C. The backflush media is alternately backflushed from the top and bottom of the composite filter element, for a total of five backflush cycles. After the backflush cycle, the composite filter element can be cycled back into the filtration cycle. Testing has shown that the composite filter element in this embodiment achieved a solid particle removal rate exceeding 99% when operated in a Fischer-Tropsch slurry bed reactor.

Claims

1. A metal composite filter element, comprising a filtration precision control layer and a support and protection layer, wherein: The filtration precision control layer is a metal tube, the supporting protective layer is at least one layer of metal porous mesh, and the supporting protective layer wraps at least a portion of the filtration precision control layer.

2. The metal composite filter element according to claim 1, wherein: The length of the metal composite filter element is between 10-2000 mm.

3. The metal composite filter element according to claim 2, wherein: The length of the metal composite filter element is between 50-1700 mm.

4. The metal composite filter element according to claim 1, wherein: At least one end of the metal composite filter element has a connecting portion with a length of 1-100 mm.

5. The metal composite filter element according to claim 4, wherein: The connection portion is a connection portion used for flange welding, quick connector connection or threaded connection.

6. The metal composite filter element according to any one of claims 1 to 5, wherein: The metal composite filter element comprises a filtration zone surrounded by a supporting protective layer, and optionally at least one closed zone.

7. The metal composite filter element according to claim 6, wherein: The metal composite filter element has more than two filtration areas and at least one closed area.

8. The metal composite filter element according to claim 6, wherein: The metal composite filter element has two, three, four, five, six or more filtration zones and closed zones between the filtration zones.

9. The metal composite filter element according to claim 6, wherein: The length of the filtration zone is / is between 1-300 mm, or 10-250 mm.

10. The metal composite filter element according to claim 6, wherein: The length of the closed area is / is between 1-50 mm, or 5-20 mm.

11. The metal composite filter element according to claim 6, wherein: The length ratio of the filtration area to the closed area is less than 50:1, or less than 30:

1.

12. The metal composite filter element according to any one of claims 1 to 5, wherein: The filtration accuracy control layer is a hollow cylinder, which includes an outer wall, an inner wall, and a wall thickness T.

13. The metal composite filter element according to claim 12, wherein: The wall thickness T is less than 1.0 mm, or 0.1-0.7 mm, or 0.1-0.5 mm.

14. The metal composite filter element according to any one of claims 1 to 5, wherein: The metal tube has an outer diameter d of less than 70 mm, or an outer diameter d in the range of 5-30 mm, or an outer diameter d in the range of 10-25 mm.

15. The metal composite filter element according to any one of claims 1 to 5, wherein: The metal tube has an open area L2 and an optional closed area L3.

16. The metal composite filter element according to claim 15, wherein: The metal tube has more than two open areas L2 and at least one closed area L3.

17. The metal composite filter element according to claim 15, wherein: The metal tube has two, three, four, five, six or more open areas and closed areas between the open areas.

18. The metal composite filter element according to claim 15, wherein: The length of the opening area L2 is / is between 1-300 mm, or 10-250 mm.

19. The metal composite filter element according to claim 15, wherein: The length of the closed area L3 is / is between 1-50 mm, or 5-20 mm.

20. The metal composite filter element according to claim 15, wherein The ratio of the total length of the open area L2 to the closed area L3 is less than 50:1, or 30:1 or less.

21. The metal composite filter element according to claim 15, wherein: The metal tube is a stainless steel tube.

22. The metal composite filter element according to claim 21, wherein: The stainless steel pipe is one of 201, 202, 301, 321, 303, 314, 305, 309, 304, 304L, 317, 316Si, 316, 316L, 309S, and SUS310S.

23. The metal composite filter element according to claim 22, wherein: The stainless steel pipe is one of 321, 304, 304L, 316, and 316L.

24. The metal composite filter element according to any one of claims 1 to 5, wherein: The metal tube further comprises a non-perforated area L1 at at least one end, with a length of 1-100 mm.

25. The metal composite filter element according to any one of claims 1 to 5, wherein: The hole shape of the metal tube is one or more of a circular hole and a strip hole.

26. The metal composite filter element according to claim 25, wherein: The micropores or holes of the metal tube have a shape with a uniform size from the outer wall to the outer wall, and the diameter is δ; or the micropores or holes of the metal tube have a forward cone shape with a larger opening diameter δ1 at the outer wall and a smaller opening diameter δ2 at the inner wall; or the micropores or holes of the metal tube have an inverted cone shape with a smaller opening diameter δ2 at the outer wall and a larger opening diameter δ1 at the inner wall.

27. The metal composite filter element according to claim 26, wherein: δ is in the range of 0.001-0.1 mm; diameter δ1 is in the range of 0.001-0.1 mm; or diameter δ2 is in the range of 0.0005-0.08 mm.

28. The metal composite filter element according to claim 26, wherein The holes or microholes are precisely drilled on the stainless steel thin-walled tube simultaneously or individually by high-power laser drilling equipment.

29. The metal composite filter element according to claim 26, wherein: The metal tube is formed from a tubular or flat sheet metal section with laser drilled holes or micro-holes therein.

30. The metal composite filter element according to claim 26, wherein The micropores or holes are arranged in a straight or rectangular format, a relatively triangular pattern, or a Pocard dot pattern.

31. The metal composite filter element according to claim 26, wherein: The pores or holes have a thickness T extending through the wall of the metal tube.

32. The metal composite filter element according to claim 26, wherein When the hole or microhole is a tapered hole, the taper angle of the hole or microhole is 0°-10°.

33. The metal composite filter element according to claim 26, wherein: At least one of the shape, diameter and orientation of the holes or pores on the metal tube remains consistent.

34. The metal composite filter element according to claim 33, wherein: In the case of tapered holes, all larger openings are on the outer wall; alternatively, the taper angle of the hole or microhole remains consistent.

35. The metal composite filter element according to any one of claims 1 to 5, wherein: The opening rate of the metal tube in the filtration accuracy control layer is 1%-60%.

36. The metal composite filter element according to any one of claims 1 to 5, wherein: The supporting protective layer is composed of one or more layers of sintered metal wire mesh, sintered metal powder, metal fiber film, or sintered metal felt.

37. The metal composite filter element according to claim 36, wherein: The supporting protective layer is composed of one or more layers of sintered metal wire mesh.

38. The metal composite filter element according to claim 36, wherein The supporting protective layer is composed of one, two, three or four or more layers of square mesh or dense mesh sintered metal wire mesh.

39. The metal composite filter element according to claim 36, wherein: The pore sizes of all layers in the supporting and protective layer are larger than or smaller than the pore size of the filtration precision control layer.

40. The metal composite filter element according to claim 36, wherein In the case of a conical hole, the pore size of all layers in the supporting protective layer is larger than the larger pore size δ1 in the filtration precision control layer; or, in the case of a conical hole, the pore size of all layers in the supporting protective layer is smaller than the smaller pore size δ2 in the filtration precision control layer.

41. The metal composite filter element according to claim 36, wherein: In the supporting protective layer, in the case of multiple layers, the pore sizes are the same; or, in the case of multiple layers, the pore sizes of the multiple layers increase or decrease layer by layer.

42. The metal composite filter element according to claim 36, wherein: The total thickness of the supporting protective layer is 0.01-1 mm, the filter pore size is 1-200 meshes, and the porosity is 1%-60%.

43. The metal composite filter element according to any one of claims 1 to 5, wherein: The combining process of the filtration accuracy control layer and the supporting protection layer is one or more of welding, winding, weaving or sintering.

44. Use of the metal composite filter element according to any one of claims 1 to 43 as an inner filter in a slurry bed reactor.

45. A method for filtering in a slurry bed reactor using the metal composite filter element according to any one of claims 1 to 43 as an inner filter, wherein: The metal composite filter element has a filtering cycle, a soaking cycle and a back-flushing cycle during filtration, and a portion of the composite filter element group is always in the filtering cycle, a portion is in the soaking cycle, and a portion is in the back-flushing cycle.

46. ​​The method of claim 45, wherein The filtration pressure difference during the filtration cycle is 1-1000KPa, or 5-100KPa; the filtration time is 5-200min or 10-100min; Immerse the filter cake inside the slurry bed reactor and use the turbulent slurry to flush the filter cake, wherein the soaking cycle time is 1-20 minutes, or 2-10 minutes; or the single backflushing duration is 1-20 seconds or 3-10 seconds; the backflushing medium pressure is 1-1000KPa, or 10-500KPa; the backflushing medium temperature is 100-300℃ or 150-200℃; the backflushing times are 1-10 times, or 3-6 times.

47. The method of claim 45, wherein The backflushing medium is gas or liquid, selected from fresh reaction gas, recycled reaction gas, inert gas or clean filtrate obtained by filtration.

48. The method of claim 45, wherein The backflush method is simple gas backflush regeneration, simple liquid backflush regeneration or a combination of gas backflush and liquid backflush.

49. The method of claim 45, wherein During the back-flushing cycle, the back-flushing medium is back-flushed into the vertically arranged composite filter element from the top; or, back-flushed into the vertically arranged composite filter element from the bottom; Alternatively, the backflushing media is alternately backflushed from the top and bottom of the composite filter element.

Images