Metal film of rotary filtering equipment and processing method of metal film

Abstract

The invention discloses a metal film of rotary filtering equipment and a processing method thereof, the metal film of the rotary filtering equipment comprises a first porous metal film layer and a second porous metal film layer, one side of the first porous metal film layer or the second porous metal film layer is provided with a spiral flow channel, and the spiral flow channel is communicated with the first porous metal film layer or the second porous metal film layer. The spiral runner is arranged on one side close to the other porous metal film layer; holes are formed in the surfaces of the first porous metal film layer and the second porous metal film layer and in the positions corresponding to the spiral flow channels; the edge area of the first porous metal film layer and the edge area of the second porous metal film layer are connected in a sealed mode to form an integrated disc structure, and through holes are formed in the center of the first porous metal film layer and the center of the second porous metal film layer. The invention relates to the technical field of filtering equipment. According to the metal film of the rotary filtering equipment and the machining method of the metal film, the technical problems of an existing metal film in the aspects of micropore machining, structural sealing, fluid guiding and the like are solved, and efficient and stable filtering performance is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of filtration equipment, and particularly to a metal membrane for a rotary filtration device and a processing method thereof. Background Art

[0002] In the field of industrial filtration, membrane separation technology has been widely used due to its high efficiency and energy conservation. Although traditional ceramic membranes have good chemical stability and microporous structures, their inherent brittleness and poor alkali resistance limit their application in strongly corrosive environments. Especially when treating high-concentration alkaline solutions, ceramic membranes are prone to structural damage, resulting in a sharp decline in filtration performance. In addition, the manufacturing cost of ceramic membranes is relatively high, and it is difficult to achieve the processing of complex structures, which further restricts their application scope.

[0003] In contrast, metal membranes have excellent mechanical strength and corrosion resistance, and can adapt to more demanding working conditions. However, the existing metal membrane technology still faces many challenges: firstly, the processing accuracy requirements for the microporous structure of metal membranes are extremely high, and it is difficult for conventional processing methods to achieve uniform and controllable micropore distribution; secondly, the welding and sealing problems of multi-layer metal membrane structures have not been effectively solved, and leakage or insufficient structural strength is likely to occur.

[0004] To address the above problems, it is urgent to develop a new type of metal membrane filter disc, which should have a precise microporous structure, reliable sealing performance, and optimized hydrodynamic design to meet the requirements of modern industry for efficient and durable filtration equipment. Summary of the Invention

[0005] (1) Technical Problems to be Solved

[0006] In view of the deficiencies of the prior art, the present invention provides a metal membrane for a rotary filtration device and a processing method thereof, which solve the technical problems of micropore processing, structural sealing, and fluid guiding of existing metal membranes, and achieve efficient and stable filtration performance.

[0007] (2) Technical Solutions

[0008] To achieve the above object, the present invention is realized through the following technical solutions: A metal membrane for a rotary filtration device includes a first porous metal membrane layer and a second porous metal membrane layer. A spiral flow channel is provided on one side of the first porous metal membrane layer or the second porous metal membrane layer. The spiral flow channel is provided on the side close to the other porous metal membrane layer. The spiral flow channel is composed of a plurality of Archimedes spiral grooves evenly distributed in the circumferential direction. The groove depth of the spiral flow channel is 0.5 - 3 mm, and the groove width of the spiral flow channel is 1 - 5 mm;

[0009] Pores are provided on the surfaces of the first porous metal film layer and the second porous metal film layer and at positions corresponding to the spiral flow channels, and the diameter of the pores is 0.1 - 10 micrometers;

[0010] The edge regions of the first porous metal film layer and the second porous metal film layer are hermetically connected to form an integrated disc structure, and a perforation is provided at the center of the first porous metal film layer and the second porous metal film layer.

[0011] Preferably, the materials of the first porous metal film layer and the second porous metal film layer are alkali-resistant metals, including but not limited to titanium alloy, Hastelloy, or stainless steel with an alumina layer coated on the surface.

[0012] Preferably, the radius of curvature of the spiral flow channel gradually decreases from the outer edge to the center of the disc, and the distance between adjacent spiral flow channels is 5 - 20 mm.

[0013] Preferably, the first porous metal film layer and the second porous metal film layer are hermetically connected by laser welding.

[0014] Preferably, the surfaces of the first porous metal film layer and the second porous metal film layer are coated with a nano-ceramic composite coating, the coating thickness is 50 - 500 nm, the coating material is zirconia or silicon nitride, and the coating covers the surface pores of the porous metal film layer and retains the pore connectivity.

[0015] A method for processing a metal film of a rotary filtration device, applicable to the metal film of the aforementioned rotary filtration device, includes the following steps:

[0016] Step 1: Process the spiral flow channel layer: Use numerical control milling to process circumferentially uniformly distributed spiral flow channels on the surface of the first porous metal film layer or the second porous metal film layer;

[0017] Step 2: Prepare the porous metal film layer: Use laser drilling or electrochemical etching to process uniform micropores with a pore diameter of 0.1 - 10 micrometers at positions corresponding to the spiral flow channels on the surfaces of the first porous metal film layer and the second porous metal film layer, and control the porosity to be 20 - 50%;

[0018] Step 3: Stack and weld: Align and stack the first porous metal film layer and the second porous metal film layer, and form a sealed welding layer in the edge region by laser welding, the welding temperature is lower than 80% of the melting point of the metal, and the pressure is 10 - 50 MPa;

[0019] Step 4: Surface treatment: Perform anodic oxidation or chemical vapor deposition on the welded disc to form a corrosion-resistant coating.

[0020] Preferably, the parameters of the welding process in step three are as follows: under an argon protection environment, the laser power is 500 - 1500 W, the welding speed is 10 - 50 mm / s, and the weld width is 0.2 - 1 mm.

[0021] Preferably, the machining accuracy of the spiral flow channel in step one is ±0.05 mm, and the surface roughness Ra of the groove is ≤1.6 μm.

[0022] Preferably, step four further includes performing plasma cleaning on the pores of the disk, with the cleaning gas being oxygen or argon and the cleaning time being 5 - 30 minutes, to remove processing residues and improve the coating adhesion.

[0023] (III) Beneficial effects

[0024] The present invention provides a metal membrane for a rotary filtration device and a processing method thereof. It has the following beneficial effects:

[0025] Excellent corrosion resistance: The combination of the metal substrate and the nano - coating enables stable operation in strong acid and strong alkali environments for a long time;

[0026] Efficient fluid guidance: The spiral flow channel design significantly improves the fluid flow efficiency and reduces particle deposition;

[0027] Reliable structural sealing: The precise welding process ensures the integrity and sealing of the multi - layer structure;

[0028] Precise machining control: Laser and numerical control technologies ensure that the key dimension accuracy reaches ±0.05 mm. Description of the drawings

[0029] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 is a schematic diagram of the structure of the first porous metal membrane layer and the second porous metal membrane layer of the present invention.

[0031] In the figure: 1 - the first porous metal membrane layer, 2 - the second porous metal membrane layer, 3 - the spiral flow channel, 4 - the perforation. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Please refer to Figure 1-2, the present invention provides a technical solution: a metal membrane for a rotary filtration equipment, comprising a first porous metal membrane layer 1 and a second porous metal membrane layer 2. On one side of the first porous metal membrane layer 1 or the second porous metal membrane layer 2, there is a spiral flow channel 3, which is arranged on the side close to the other porous metal membrane layer. The spiral flow channel 3 is composed of a plurality of Archimedean spiral grooves evenly distributed circumferentially. The groove depth of the spiral flow channel 3 is 0.5 - 3 mm, and the groove width of the spiral flow channel 3 is 1 - 5 mm;

[0034] On the surfaces of the first porous metal membrane layer 1 and the second porous metal membrane layer 2 and at the position corresponding to the spiral flow channel 3, there are pores with a diameter of 0.1 - 10 microns;

[0035] The edge regions of the first porous metal membrane layer 1 and the second porous metal membrane layer 2 are hermetically connected to form an integrated disc structure, and a perforation 4 is provided at the center of the first porous metal membrane layer 1 and the second porous metal membrane layer 2.

[0036] The materials of the first porous metal membrane layer 1 and the second porous metal membrane layer 2 are alkali-resistant metals, including but not limited to titanium alloy, Hastelloy, or stainless steel with an alumina layer coated on the surface.

[0037] The curvature radius of the spiral flow channel 3 gradually decreases from the outer edge to the center of the disc, and the distance between adjacent spiral flow channels 3 is 5 - 20 mm.

[0038] The first porous metal membrane layer 1 and the second porous metal membrane layer 2 are hermetically connected by laser welding.

[0039] The surfaces of the first porous metal membrane layer 1 and the second porous metal membrane layer 2 are coated with a nano-ceramic composite coating with a coating thickness of 50 - 500 nm. The coating material is zirconia or silicon nitride, and the coating covers the surface pores of the porous metal membrane layer and retains the pore connectivity.

[0040] A processing method for the metal membrane of a rotary filtration equipment, which is applicable to the metal membrane of the above-mentioned rotary filtration equipment, comprises the following steps:

[0041] Step 1: Process the spiral flow channel layer: Use numerical control milling to process circumferentially evenly distributed spiral flow channels on the surface of the first porous metal membrane layer 1 or the second porous metal membrane layer 2;

[0042] Step 2: Prepare the porous metal membrane layer: Use laser drilling or electrochemical etching to process uniform micropores with a pore diameter of 0.1 - 10 microns on the surfaces of the first porous metal membrane layer 1 and the second porous metal membrane layer 2 and at the positions corresponding to the spiral flow channels, and control the porosity to be 20 - 50%;

[0043] Step 3: Laminated welding: Align and stack the first porous metal film layer 1 and the second porous metal film layer 2, and form a sealed welding layer in the edge area by laser welding. The welding temperature is lower than 80% of the metal melting point, and the pressure is 10 - 50 MPa;

[0044] Step 4: Surface treatment: Perform anodic oxidation or chemical vapor deposition on the welded disc to form a corrosion-resistant coating.

[0045] The parameters of the welding process in Step 3 are: Under the protective environment of argon gas, the laser power is 500 - 1500 W, the welding speed is 10 - 50 mm / s, and the weld width is 0.2 - 1 mm.

[0046] The machining accuracy of the spiral flow channel in Step 1 is ±0.05 mm, and the surface roughness Ra of the groove is ≤1.6 μm.

[0047] In Step 4, it also includes plasma cleaning of the pores of the disc. The cleaning gas is oxygen or argon, and the cleaning time is 5 - 30 minutes to remove processing residues and improve the coating adhesion.

[0048] Example 1: Preparation of metal film filter disc

[0049] 1. Substrate preparation:

[0050] Select a 1 mm thick TA2 titanium alloy plate, which is the first porous metal film layer;

[0051] Select a 2.5 mm thick 316L stainless steel plate as the second porous metal film layer;

[0052] 2. Spiral flow channel machining:

[0053] Machine a spiral flow channel on the 2.5 mm stainless steel plate;

[0054] Machining parameters: Use a high-precision five-axis CNC milling machine, spindle speed 6000 rpm, feed speed 400 mm / min, and use a 0.5 mm diameter tungsten steel milling cutter;

[0055] Flow channel dimensions: groove depth 1.5 mm, groove width 3 mm, center distance between adjacent flow channels 12 mm, spiral angle 15°;

[0056] Post-treatment: Electrochemical polishing treatment, surface roughness Ra ≤1.0 μm;

[0057] 3. Micropore machining:

[0058] Machine micropores at the corresponding flow channel positions on the 1 mm titanium alloy plate and the 2.5 mm thick 316L stainless steel plate

[0059] Adopt an ultraviolet laser drilling system: wavelength 355 nm, pulse width 20 ns, single-pulse energy 0.8 mJ, repetition frequency 50 kHz;

[0060] Hole type parameters: aperture 2.5 ± 0.2 μm, hole density 8000 holes / mm 2 , porosity 38 ± 2%

[0061] 4. Stacked welding:

[0062] The titanium alloy plate is at the bottom, the stainless steel plate is on the top, the flow channel faces the titanium alloy plate, and the micro-holes on the surface of the titanium alloy plate are aligned with the flow channel;

[0063] Welding process: Use a fiber laser welding machine, power 800 W, welding speed 20 mm / s, spot diameter 0.3 mm, argon protection flow rate 20 L / min;

[0064] Weld requirements: weld width 0.8 mm, penetration depth 0.5 mm, porosity < 0.5%;

[0065] 5. Surface treatment:

[0066] Micro-arc oxidation treatment:

[0067] Electrolyte: sodium silicate system, current density 15 A / dm 2 , treatment time 40 min, forming a ceramic layer with a thickness of 5 - 8 μm;

[0068] Post-treatment: Use ultrasonic cleaning at 40 kHz, clean for 30 min, and dry at 120 °C.

[0069] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0070] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A metal membrane for a rotary filtration device, characterized in that: The invention comprises a first porous metal film layer (1) and a second porous metal film layer (2), wherein a spiral flow channel (3) is arranged on one side of the first porous metal film layer (1) or the second porous metal film layer (2), the spiral flow channel (3) is arranged on a side close to the other porous metal film layer, the spiral flow channel (3) is composed of a plurality of Archimedean spiral grooves uniformly distributed in the circumferential direction, the groove depth of the spiral flow channel (3) is 0.5-3 mm, and the groove width of the spiral flow channel (3) is 1-5 mm; Pores are provided on the surfaces of the first porous metal membrane layer (1) and the second porous metal membrane layer (2) at positions corresponding to the spiral flow channel (3), and the diameter of the pores is 0.1-10 micrometers; The edge regions of the first porous metal membrane layer (1) and the second porous metal membrane layer (2) are sealed and connected to form an integrated disc structure, and the centers of the first porous metal membrane layer (1) and the second porous metal membrane layer (2) are provided with perforations (4).

2. The metal membrane of a rotary filtration equipment according to claim 1, characterized in that: The material of the first porous metal film layer (1) and the second porous metal film layer (2) is an alkali-resistant metal, including but not limited to titanium alloy, Hastelloy alloy or stainless steel with an aluminum oxide layer coated on the surface.

3. The metal membrane of a rotary filtration equipment according to claim 1, characterized in that: The radius of curvature of the spiral flow channel (3) gradually decreases from the outer edge to the center of the disc, and the spacing between adjacent spiral flow channels (3) is 5-20 mm.

4. The metal membrane of a rotary filtration equipment according to claim 1, characterized in that: The first porous metal membrane layer (1) and the second porous metal membrane layer (2) are sealed by laser welding.

5. The metal membrane of a rotary filtration equipment according to claim 1, characterized in that: The surfaces of the first porous metal membrane layer (1) and the second porous metal membrane layer (2) are coated with a nano-ceramic composite coating with a coating thickness of 50-500nm. The coating material is zirconium oxide or silicon nitride. The coating covers the surface pores of the porous metal membrane layer and retains the pore connectivity.

6. A method for processing a metal membrane of a rotary filtering device, applicable to a metal membrane of a rotary filtering device according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: machining a spiral flow channel layer: machining a spiral flow channel evenly distributed in the circumferential direction on the surface of the first porous metal film layer (1) or the second porous metal film layer (2) by using CNC milling; Step 2: preparing a porous metal film layer: processing uniform micropores on the surface of the first porous metal film layer (1) and the second porous metal film layer (2) at positions corresponding to the spiral flow channel by laser drilling or electrochemical etching, with a pore size of 0.1-10 microns and a porosity controlled at 20-50%; Step 3: stacking welding: aligning and stacking the first porous metal film layer (1) and the second porous metal film layer (2), and forming a sealing welding layer in the edge area by laser welding, wherein the welding temperature is lower than 80% of the melting point of the metal and the pressure is 10-50 MPa; Step 4: Surface treatment: Anodize or chemical vapor deposit the welded disc to form a corrosion-resistant coating.

7. The method for processing a metal film of a rotary filtering device according to claim 6, characterized in that: The parameters of the welding process in step three are: in an argon protection environment, the laser power is 500-1500W, the welding speed is 10-50mm / s, and the weld width is 0.2-1mm.

8. The method for processing a metal film of a rotary filtering device according to claim 6, characterized in that: The processing accuracy of the spiral flow channel in the step 1 is ±0.05 mm, and the groove surface roughness Ra≤1.6 μm.

9. The method for processing a metal film of a rotary filtering device according to claim 6, characterized in that: The step 4 also includes plasma cleaning the pores of the disc, with the cleaning gas being oxygen or argon for 5-30 minutes to remove processing residues and improve coating adhesion.

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