A method for processing a metal screen for a centrifuge

Abstract

The application discloses a processing method of metal screen mesh for centrifuges, which comprises the following steps: 1) cutting stainless steel plates into steel strips with rectangular cross sections by using a laser cutting device, and deburring and straightening the steel strips; 2) positioning and clamping a plurality of steel strips by using a fixing device, so as to ensure that the gap size of the screen mesh to be processed meets the design requirements; 3) forming a screen mesh blank I by using a laser cladding method to weld a L1-wide stainless steel coating on the upper end surface of the steel strip at a spacing L2; 4) forming a screen mesh blank II by using an argon arc welding method to weld the steel strips at a spacing L2 and a welding seam length L1; and 5) performing mechanical processing on the screen mesh blank, bending and forming the screen mesh blank on the fixing device to obtain a finished product. The application has the advantages of simple operation, less processing equipment and occupied space. Moreover, the application no longer needs to use a saw blade, reduces the consumption of materials, and lowers the production cost. In addition, the application can process screen meshes with different gap sizes, and solves the problem that it is not easy to process screen meshes with small gap sizes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid-liquid separation equipment, in particular to a processing method of metal screen for centrifuge. BACKGROUND

[0002] In the industrial production process of chemical industry, mining and metallurgy, a large amount of waste liquid containing slag and organic residues will be produced, which will cause serious pollution to soil and rivers. The centrifuge is a device for solid-liquid separation of these waste liquids, and the strip-shaped metal screen is a key component of the device. According to the size of the separated material particles, the screen gap is generally 0.1 to 0.3 mm. In the solid-liquid separation process, in order to prevent the solid particles of different particle sizes from blocking the screen gap and to facilitate cleaning, the screen gap is processed into a trapezoidal structure, that is, the inner side (working surface) gap size is small, and the outer side gap size is large.

[0003] The existing centrifuge strip-shaped screen adopts saw blade milling, laser cutting and steel bar combined welding forming process. The saw blade milling is to mill the inner surface of the stainless steel pipe of a certain size and wall thickness on the lathe first, and then mill the gap along the axial direction on the milling machine with a saw blade milling cutter. The last one is cut, reversed and bent to obtain the required screen. This method has low milling speed and requires more milling machines due to the large number of gaps. At the same time, due to the high hardness of stainless steel, the saw blade is easy to wear, which increases the material consumption. Laser cutting can process screen with gap width of 0.05 mm or more and high hardness material, which has high processing efficiency. However, this method cannot process trapezoidal structure and can only process thin plate screen, so the rigidity of the screen is poor and deformation is easy to occur. The steel bar combined welding forming process is to process the rectangular cross section stainless steel bar into trapezoidal cross section on the special fixing device, and then weld the steel bar by plasma powder welding process. Compared with the saw blade milling method, this process has high processing efficiency and small occupied working site. However, the main disadvantage is that the rectangular cross section steel bar needs to be processed into trapezoidal cross section steel bar twice, and the steel bar will be deformed during grinding due to the grinding force, which needs to be straightened again, thus increasing the processing procedure. SUMMARY

[0004] In order to solve the above technical problems, the present application provides a processing method of metal screen for centrifuge, which is simple to operate, reduces equipment investment, saves raw materials, reduces consumables and reduces processing procedures.

[0005] The technical scheme for solving the above problems is: a processing method of metal screen for centrifuge, comprising the following steps:

[0006] 1) cutting a stainless steel plate with a thickness of b into a steel bar with a rectangular cross section by a laser cutting device, and deburring and straightening the steel bar;

[0007] 2) Position and clamp several steel bars using a fixing device to ensure that the gap size of the screen to be processed meets the design requirements;

[0008] 3) Using laser cladding, a stainless steel coating of width L1 is deposited on the upper end face of the steel strip at a spacing L2 to form a screen blank I;

[0009] 4) The steel bars are welded together using argon arc welding at a spacing of L2 and a weld length of L1 to form a screen blank II;

[0010] 5) The screen blank is machined and bent into shape on a fixed device to obtain the finished product.

[0011] In the above-mentioned processing method for metal screens used in centrifuges, in step 2), the fixing device includes a lower base plate and an upper pressure plate. The lower base plate is processed with equilateral trapezoidal grooves and equilateral trapezoidal teeth. The bottom width of the trapezoidal groove, b1, is 2b+c, where c is the screen gap size of the screen to be processed. The bottom width of the trapezoidal teeth is b2, the top width is b3, and the height is H1. The upper pressure plate is also processed with equilateral trapezoidal grooves and equilateral trapezoidal teeth. The bottom width of the trapezoidal groove is b4, the bottom width of the trapezoidal teeth is b5, the top width is b6, and the height is H2. When the upper pressure plate and the lower base plate are combined, the center line of the trapezoidal teeth in the upper pressure plate coincides with the center line of the trapezoidal groove in the lower base plate.

[0012] The processing method of the metal screen for centrifuge described above, specifically step 2) is as follows: place the steel bars in the trapezoidal groove of the bottom plate of the fixing device, arrange two steel bars in one trapezoidal groove and attach them to the two sides of the trapezoidal groove respectively, then place the upper pressure plate on the trapezoidal groove to make the steel bars flush, and then press the upper pressure plate and the bottom plate together with screws. At this time, the steel bars are distributed in a zigzag pattern in the fixing device.

[0013] The processing method for the metal screen used in the centrifuge described above, specifically step 3), is as follows: the fixing device is placed on the laser powder cladding fixture platform, the center line of the coating to be welded is adjusted to be in the same vertical plane as the direction of the welding gun, and the starting position of the welding gun is adjusted. Then the fixing device is fixed on the welding machine fixture platform; the laser welding machine is turned on, and after the first stainless steel coating T1 is welded, the position of the welding gun is adjusted again, and the next stainless steel coating is welded until all the designed stainless steel coatings are welded, forming a screen blank I.

[0014] The processing method for the metal screen used in the centrifuge described above, specifically step 4), is as follows: the fixing device is placed on the argon arc welding workbench and fixed, the argon arc welding machine is turned on, and the stainless steel strips are welded together according to the designed weld position and length to form a screen blank II.

[0015] The processing method for the metal screen used in the centrifuge described above, specifically step 5), is as follows: First, the working surface of the flat screen blank I or flat screen blank II is ground, and the roughness of the working surface after grinding is less than 1.6 micrometers; then the mounting surface is ground to process the screen thickness to the design size; then, the two end faces and two side faces of the screen are milled according to the design size and parallelism and perpendicularity tolerance requirements of the screen to obtain a flat screen; finally, the finely processed flat screen is bent into shape on a special mold to obtain an arc-shaped screen.

[0016] The above-mentioned processing method for metal screens used in centrifuges includes the following steps after step 5): remanufacturing the failed screen. First, the failed screen is leveled, and then the gap on the working surface is adjusted to the design size using a fixing device, and the gap size is fixed. Then, after grinding the working surface of the flat screen, the finely processed flat screen is bent into shape on a special mold to obtain an arc-shaped screen.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. This invention is simple to operate, increasing product production efficiency by more than 20 times compared to saw blade milling methods, while requiring less processing equipment and space. Furthermore, it eliminates the need for saw blades, reducing material consumption and lowering production costs.

[0019] 2. Compared with the existing steel bar combination welding forming process, the present invention reduces the two clamping, two grinding and re-straightening processes of processing rectangular cross-section steel bars into trapezoidal steel bars, and the re-straightening process of the deformed trapezoidal steel bars after grinding, thereby further improving the production efficiency of the product.

[0020] 3. This invention can process screens with different gap sizes, and is not affected by material supply or saw blade thickness. In particular, it solves the problem that smaller gap sizes are not easy to process.

[0021] 4. This invention can process larger screens, reducing the time and difficulty of installing screens during machine assembly and lowering the labor intensity of workers.

[0022] 5. This invention can use stainless steel with high hardness as the screen material to make metal screens, which improves the wear resistance and service life of the screens. At the same time, it can reduce the thickness of the steel bars, increase the number of gaps per unit length, increase the water permeability during equipment operation, and improve the operating efficiency of the equipment.

[0023] 6. This invention eliminates the need for milling stainless steel pipes or grinding stainless steel bars, saving more than 25% of the stainless steel material used for screens, conserving resources and reducing production costs.

[0024] 7. After the metal screen processed by this invention fails, the screen can be recycled and remanufactured, reducing resource consumption. Attached Figure Description

[0025] Figure 1 is a process flow diagram of the present invention.

[0026] Figure 2 This is a front view of the lower base plate structure of the fixing device of the present invention.

[0027] Figure 3 This is a top view of the lower base plate structure of the fixing device of the present invention.

[0028] Figure 4 This is a front view of the upper pressure plate of the fixing device of the present invention.

[0029] Figure 5 This is a top view of the upper pressure plate of the fixing device of the present invention.

[0030] Figure 6 This is a front view of the fixing device of the present invention.

[0031] Figure 7 This is a top view of the fixing device of the present invention.

[0032] Figure 8 This is a front view of the metal screen blank I processed by laser powder cladding welding according to the present invention.

[0033] Figure 9 This is a top view of the metal screen blank I processed by laser powder cladding welding according to the present invention.

[0034] Figure 10 This is a front view of the metal screen blank II produced by argon arc welding according to the present invention.

[0035] Figure 11 This is a top view of the metal screen blank II produced by argon arc welding according to the present invention. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] like Figure 1 As shown, a method for processing a metal screen for a centrifuge includes the following steps:

[0038] 1) Use laser cutting equipment to cut stainless steel sheet with thickness b into steel strips with rectangular cross sections, and deburr and straighten the steel strips.

[0039] 2) Position and clamp several steel bars using a fixing device to ensure that the gap size of the screen to be processed meets the design requirements.

[0040] like Figures 2-7As shown, the fixing device includes a lower base plate 2 and an upper pressure plate 1. The lower base plate 2 is machined with an equilateral trapezoidal groove and equilateral trapezoidal teeth. The bottom width of the trapezoidal groove is b1, which is 2b+c; the bottom width of the trapezoidal teeth is b2; the top width of the teeth is b3; and the tooth height is H1. The upper pressure plate is also machined with an equilateral trapezoidal groove and equilateral trapezoidal teeth. The bottom width of the trapezoidal groove is b4; the bottom width of the trapezoidal teeth is b5; the top width of the teeth is b6; and the tooth height is H2. When the upper pressure plate 1 and the lower base plate 2 are combined, the center line of the trapezoidal teeth in the upper pressure plate 1 coincides with the center line of the trapezoidal groove in the lower base plate 2. The upper pressure plate 1 and the lower base plate 2 are fastened together with screws 3, so that the two steel bars 4 in the trapezoidal groove are tightly fitted to the two sides of the trapezoidal groove, and the two steel bars on both sides of the trapezoidal teeth are distributed in an inverted V shape.

[0041] The specific process of step 2) is as follows: place the steel strip 4 in the trapezoidal groove of the bottom plate 2 of the fixing device, arrange two steel strips 4 in one trapezoidal groove and attach them to the two sides of the trapezoidal groove respectively, then place the upper pressure plate 1 on the trapezoidal groove to make the steel strip 4 flush, and then press the upper pressure plate 1 and the bottom plate 2 together with screws 3. At this time, the steel strip 4 are arranged in an inverted V shape in the fixing device.

[0042] 3) Using laser cladding, stainless steel coating 5 with a width of L1 is deposited on the upper end face of the steel strip at a spacing of L2 to form a screen blank I.

[0043] Step 3) The specific process is as follows: Place the fixing device on the laser powder cladding fixture platform, adjust the center line of the coating to be welded to be in the same vertical plane as the direction of the welding gun, and adjust the starting position of the welding gun. Then fix the fixing device on the welding machine fixture platform; turn on the laser welding machine. After the first stainless steel coating T1 is welded, adjust the position of the welding gun again and weld the next stainless steel coating until all the designed stainless steel coatings are welded to form a screen blank I.

[0044] 4) The steel bars are welded together using argon arc welding at a spacing of L2 and a weld length of L1 to form a screen blank II.

[0045] Step 4) The specific process is as follows: Place the fixing device on the argon arc welding workbench and fix it, turn on the argon arc welding machine, and weld the stainless steel strips according to the designed weld position and length to form a screen blank II.

[0046] 5) The screen blank is machined and bent into shape on a fixed device to obtain the finished product.

[0047] Step 5) The specific process is as follows: First, grind the working surface of the flat screen blank I or flat screen blank II until the roughness of the working surface is less than 1.6 micrometers; then grind the mounting surface 7 to process the screen thickness to the design size; then mill the two end faces and two side faces of the screen according to the design size and parallelism and perpendicularity tolerance requirements of the screen to obtain a flat screen; finally, bend the finely processed flat screen into shape on a special mold to obtain an arc-shaped screen.

[0048] Step 5) is followed by the following steps: remanufacturing the failed screen due to increased wear gap size, leveling the failed screen, adjusting the gap on the working surface to the design size using a fixing device, and fixing the gap size; then grinding the working surface of the flat screen, bending the finished flat screen into a circular arc shape on a special mold. Example 1

[0049] (1) Use laser cutting equipment to cut stainless steel plate with a thickness of 0.8mm into steel bars with a rectangular cross section. The steel bars are 120mm×5.5mm×0.8mm in size, and the steel bars are deburred and straightened.

[0050] (2) Place the rectangular steel bar on the fixing device, wherein the bottom width of the trapezoidal groove of the lower base plate is b1 = 1.8 mm, the bottom width of the trapezoidal tooth is b2 = 0.6 mm, the top width of the tooth is b3 = 0.1 mm, and the tooth height is H1 = 5 mm; the bottom width of the trapezoidal groove of the upper pressure plate is b4 = 1.6 mm, the bottom width of the trapezoidal tooth is b5 = 0.8 mm, the top width of the tooth is b6 = 0.2 mm, and the tooth height is H2 = 6 mm; make the two ends of the steel bar in the fixing device flush, and then clamp it, see Figure 6 .

[0051] (3) Place the fixing device on the laser powder cladding fixture platform, adjust the center line of the coating to be welded to be in the same vertical plane as the direction of the welding gun, and adjust the starting position of the welding gun. Then fix the fixing device on the welding machine fixture platform and set the welding process parameters. Turn on the laser welding machine. After the first stainless steel coating T1 is welded, adjust the position of the welding gun again and weld the next stainless steel coating until all four stainless steel coatings are welded to form a screen blank I. The coating width L1 of the screen blank I is 4.5 mm, and the interval between the two coatings L2 is 34 mm.

[0052] (4) Grind the working surface of the flat screen blank I. The roughness of the working surface after grinding is less than 1.6 micrometers. Then process the mounting surface to make the screen thickness to the design size. Then mill the two ends and two sides of the screen according to the design size and the parallelism and perpendicularity tolerance requirements of the screen to obtain the flat screen. Finally, bend the finished flat screen on a special mold to obtain an arc-shaped screen with a screen gap size of 0.2mm. Example 2

[0053] (1) Use laser cutting equipment to cut stainless steel plate with a thickness of 1.0mm into steel bars with a rectangular cross section. The steel bars are 120mm×5.5mm×1.0mm in size, and the steel bars are deburred and straightened.

[0054] (2) Place the rectangular steel bar on the fixing device, wherein the bottom edge width of the trapezoidal groove of the lower base plate is b1, which is 2.15mm; the bottom edge width of the trapezoidal tooth is b2, which is 0.6mm; the top edge width of the tooth is b3, which is 0.1mm; and the tooth height is H1, which is 5mm. The bottom edge width of the trapezoidal groove of the upper pressure plate is b4, which is 2.0mm; the bottom edge width of the trapezoidal tooth is b5, which is 0.75mm; the top edge width of the tooth is b6, which is 0.15mm; and the tooth height is H2, which is 6mm. Make the two ends of the steel bar in the fixing device flush, and then clamp it. See Figure 6 .

[0055] (3) Place the fixing device on the laser powder cladding fixture platform, adjust the center line of the coating to be welded to be in the same vertical plane as the direction of the welding gun, and adjust the starting position of the welding gun. Then fix the fixing device on the welding machine fixture platform and set the welding process parameters. Turn on the laser welding machine. After the first stainless steel coating T1 is welded, adjust the position of the welding gun again and weld the next stainless steel coating until all four stainless steel coatings are welded to form a screen blank I. The coating width L1 of the screen blank I is 4.5 mm, and the interval between the two coatings L2 is 34 mm.

[0056] (4) Grind the working surface of the flat screen blank I. The roughness of the working surface after grinding is less than 1.6 micrometers. Then process the mounting surface to make the screen thickness to the design size. Then mill the two ends and two sides of the screen according to the design size and the parallelism and perpendicularity tolerance requirements of the screen to obtain the flat screen. Finally, bend the finished flat screen on a special mold to obtain an arc-shaped screen with a screen gap size of 0.15mm. Example 3

[0057] (1) Use laser cutting equipment to cut stainless steel plate with a thickness of 1.2mm into steel strips with a rectangular cross section. The steel strips are 120mm×5.5mm×1.2mm in size, and the steel strips are deburred and straightened.

[0058] (2) Place the rectangular steel bar on the fixing device, wherein the bottom width of the trapezoidal groove of the lower base plate is b1 = 2.5 mm, the bottom width of the trapezoidal tooth is b2 = 0.6 mm, the top width of the tooth is b3 = 0.1 mm, and the tooth height is H1 = 5 mm; the bottom width of the trapezoidal groove of the upper pressure plate is b4 = 2.4 mm, the bottom width of the trapezoidal tooth is b5 = 0.7 mm, the top width of the tooth is b6 = 0.1 mm, and the tooth height is H2 = 6 mm; make the two ends of the steel bar in the fixing device flush, and then clamp it, see Figure 6 Place the rectangular steel bar on the fixing device with a bottom edge width of 2.5mm, a bottom width of 0.6mm, and a tooth height of 5mm on the upper and lower base plates, ensuring both ends are flush, and then clamp it. See [link to device]. Figure 6 .

[0059] (3) Place the fixing device on the laser powder cladding fixture platform, adjust the center line of the coating to be welded to be in the same vertical plane as the direction of the welding gun, and adjust the starting position of the welding gun. Then fix the fixing device on the welding machine fixture platform and set the welding process parameters. Turn on the laser welding machine. After the first stainless steel coating T1 is welded, adjust the position of the welding gun again and weld the next stainless steel coating until all four stainless steel coatings are welded to form a screen blank I. The coating width L1 of the screen blank I is 4.5 mm, and the interval between the two coatings L2 is 34 mm.

[0060] (4) Grind the working surface of the flat screen blank I. The roughness of the working surface after grinding is less than 1.6 micrometers. Then process the mounting surface to make the screen thickness to the design size. Then mill the two ends and two sides of the screen according to the design size and the parallelism and perpendicularity tolerance requirements of the screen to obtain the flat screen. Finally, bend the finished flat screen on a special mold to obtain an arc-shaped screen with a screen gap size of 0.1mm. Example 4

[0061] (1) Use laser cutting equipment to cut stainless steel plate with a thickness of 1.2mm into steel strips with a rectangular cross section. The steel strips are 120mm×5.5mm×1.2mm in size, and the steel strips are deburred and straightened.

[0062] (2) Place the rectangular steel bar on the fixing device, wherein the bottom width of the trapezoidal groove of the lower base plate is b1 = 2.5 mm, the bottom width of the trapezoidal tooth is b2 = 0.6 mm, the top width of the tooth is b3 = 0.1 mm, and the tooth height is H1 = 5 mm; the bottom width of the trapezoidal groove of the upper pressure plate is b4 = 2.4 mm, the bottom width of the trapezoidal tooth is b5 = 0.7 mm, the top width of the tooth is b6 = 0.1 mm, and the tooth height is H2 = 6 mm; make the two ends of the steel bar in the fixing device flush, and then clamp it, seeFigure 6 .

[0063] (3) Place the fixing device on the laser powder cladding fixture platform, adjust the center line of the coating to be welded to be in the same vertical plane as the direction of the welding gun, and adjust the starting position of the welding gun. Then fix the fixing device on the welding machine fixture platform and set the welding process parameters. Turn on the laser welding machine. After the first stainless steel coating T1 is welded, adjust the position of the welding gun again and weld the next stainless steel coating until all three designed stainless steel coatings are welded to form a screen blank I. The coating width L1 of the screen blank I is 8mm, and the interval between the two coatings L2 is 48mm.

[0064] (4) Grind the working surface of the flat screen blank I. The roughness of the working surface after grinding is less than 1.6 micrometers. Then process the mounting surface to make the screen thickness to the design size. Then mill the two ends and two sides of the screen according to the design size and the parallelism and perpendicularity tolerance requirements of the screen to obtain the flat screen. Finally, bend the finished flat screen on a special mold to obtain an arc-shaped screen with a screen gap size of 0.1mm. Example 5

[0065] (1) Use laser cutting equipment to cut stainless steel plate with a thickness of 1.0mm into steel bars with a rectangular cross section. The steel bars are 120mm×6.2mm×1.0mm in size, and the steel bars are deburred and straightened.

[0066] (2) Place the rectangular steel bar on the fixing device, wherein the bottom edge width of the trapezoidal groove of the lower base plate is b1, which is 2.15mm; the bottom edge width of the trapezoidal tooth is b2, which is 0.65mm; the top edge width of the tooth is b3, which is 0.1mm; and the tooth height is H1, which is 5.5mm. The bottom edge width of the trapezoidal groove of the upper pressure plate is b4, which is 2.0mm; the bottom edge width of the trapezoidal tooth is b5, which is 0.8mm; the top edge width of the tooth is b6, which is 0.15mm; and the tooth height is H2, which is 6.5mm. Make the two ends of the steel bar in the fixing device flush, and then clamp it. See Figure 6 .

[0067] (3) Fix the fixing device on the argon arc welding workbench and set the argon arc welding process parameters; turn on the argon arc welding machine and weld the stainless steel strips according to the designed weld position and length to form a screen blank II. The welding length L1 of the screen blank II is 4.5 mm and the weld interval L2 is 34 mm.

[0068] (4) Grind the working surface of the flat screen blank II. After grinding, the roughness of the working surface is less than 1.6 micrometers. Then process the mounting surface to make the screen thickness to the design size. Then mill the two ends and two sides of the screen according to the design size and the parallelism and perpendicularity tolerance requirements of the screen to obtain the flat screen. Finally, bend the finished flat screen on a special mold to obtain an arc-shaped screen with a screen gap size of 0.15mm. Example 6

[0069] (1) Use laser cutting equipment to cut stainless steel plate with a thickness of 1.0mm into steel bars with a rectangular cross section. The steel bars are 120mm×6.2mm×1.0mm in size, and the steel bars are deburred and straightened.

[0070] (2) Place the rectangular steel bar on the fixing device, wherein the bottom width of the trapezoidal groove of the lower base plate is b1, which is 2.2 mm; the bottom width of the trapezoidal tooth is b2, which is 0.65 mm; the top width of the tooth is b3, which is 0.1 mm; and the tooth height is H1, which is 5.5 mm. The bottom width of the trapezoidal groove of the upper pressure plate is b4, which is 2 mm; the bottom width of the trapezoidal tooth is b5, which is 0.85 mm; the top width of the tooth is b6, which is 0.2 mm; and the tooth height is H2, which is 6.5 mm. Make the two ends of the steel bar in the fixing device flush, and then clamp it. See Figure 6 .

[0071] (3) Fix the fixing device on the argon arc welding workbench and set the argon arc welding process parameters; turn on the argon arc welding machine and weld the stainless steel strips according to the designed weld position and length to form a screen blank II. The stainless steel strips in the screen blank II are connected by 7 welds, with a welding length L1 of 4.0 mm and a weld interval L2 of 25 mm.

[0072] (4) Grind the working surface of the flat screen blank II. After grinding, the roughness of the working surface is less than 1.6 micrometers. Then process the mounting surface to make the screen thickness to the design size. Then mill the two ends and two sides of the screen according to the design size and the parallelism and perpendicularity tolerance requirements of the screen to obtain the flat screen. Finally, bend the finished flat screen on a special mold to obtain an arc-shaped screen with a screen gap size of 0.2mm. Example 7

[0073] (1) Use laser cutting equipment to cut stainless steel plate with a thickness of 1.2mm into steel bars with a rectangular cross section. The steel bars are 335mm×5.5mm×1.2mm in size, and the steel bars are deburred and straightened.

[0074] (2) Place the rectangular steel bar on the fixing device, wherein the bottom width of the trapezoidal groove of the lower base plate is b1 = 2.5 mm, the bottom width of the trapezoidal tooth is b2 = 0.6 mm, the top width of the tooth is b3 = 0.1 mm, and the tooth height is H1 = 5 mm; the bottom width of the trapezoidal groove of the upper pressure plate is b4 = 2.4 mm, the bottom width of the trapezoidal tooth is b5 = 0.7 mm, the top width of the tooth is b6 = 0.1 mm, and the tooth height is H2 = 6 mm; make the two ends of the steel bar in the fixing device flush, and then clamp it, see Figure 6 .

[0075] (3) Place the fixing device on the laser powder cladding fixture platform, adjust the center line of the coating to be welded to be in the same vertical plane as the direction of the welding gun, and adjust the starting position of the welding gun. Then fix the fixing device on the welding machine fixture platform and set the welding process parameters. Turn on the laser welding machine. After the first stainless steel coating T1 is welded, adjust the position of the welding gun again and weld the next stainless steel coating until all 11 designed stainless steel coatings are welded to form a screen blank I. The coating width L1 of the screen blank I is 5mm, and the interval between the two coatings L2 is 28mm.

[0076] (4) Grind the working surface of the flat screen blank I. The roughness of the working surface after grinding is less than 1.6 micrometers. Then process the mounting surface to make the screen thickness to the design size. Then mill the two ends and two sides of the screen according to the design size and the parallelism and perpendicularity tolerance requirements of the screen to obtain the flat screen. Finally, bend the finished flat screen on a special mold to obtain an arc-shaped screen with a screen gap size of 0.1mm. Example 8

[0077] (1) Use laser cutting equipment to cut stainless steel plate with a thickness of 1.2mm into steel bars with a rectangular cross section. The steel bars are 240mm×6.2mm×1.2mm in size, and the steel bars are deburred and straightened.

[0078] (2) Place the rectangular steel bar on the fixing device, wherein the bottom edge width of the trapezoidal groove of the lower base plate is b1, which is 2.6 mm; the bottom edge width of the trapezoidal tooth is b2, which is 0.65 mm; the top edge width of the tooth is b3, which is 0.1 mm; and the tooth height is H1, which is 5.5 mm. The bottom edge width of the trapezoidal groove of the upper pressure plate is b4, which is 2.4 mm; the bottom edge width of the trapezoidal tooth is b5, which is 0.85 mm; the top edge width of the tooth is b6, which is 0.2 mm; and the tooth height is H2, which is 6.5 mm. Make the two ends of the steel bar in the fixing device flush, and then clamp it. See Figure 6 .

[0079] (3) Fix the fixing device on the argon arc welding workbench and set the argon arc welding process parameters; turn on the argon arc welding machine and weld the stainless steel strips according to the designed weld position and length to form a screen blank II. The stainless steel strips in the screen blank II are connected by 7 welds, with a welding length L1 of 3mm and a weld interval L2 of 28mm.

[0080] (4) Grind the working surface of the flat screen blank II. After grinding, the roughness of the working surface is less than 1.6 micrometers. Then process the mounting surface to make the screen thickness to the design size. Then mill the two ends and two sides of the screen according to the design size and the parallelism and perpendicularity tolerance requirements of the screen to obtain the flat screen. Finally, bend the finished flat screen on a special mold to obtain an arc-shaped screen with a screen gap size of 0.2mm. Example 9

[0081] When a centrifuge screen is in operation, its working surface comes into contact with hard particles in the waste liquid, causing abrasive wear. This leads to a reduction in screen thickness and an increase in screen gap size. When the screen gap width increases to a certain size, the centrifuge's separation effect deteriorates, requiring screen replacement. Because the centrifuge screen of this invention has a special structure, it is possible to remanufacture a worn-out screen. The steps are as follows:

[0082] (1) The present invention takes the remanufacturing of the centrifuge screen processed in Example 6 after failure as an example. The failed arc-shaped screen is leveled, and then the screen is ultrasonically cleaned to remove the residue in the screen gaps, and then dried;

[0083] (2) Place the screen on the fixing device with the working surface facing upwards. The bottom width of the trapezoidal groove of the lower plate is b1 = 2mm, the bottom width of the trapezoidal tooth is b2 = 0.85mm, the top width of the tooth is b3 = 0.2mm, and the tooth height is H1 = 4.5mm; the bottom width of the trapezoidal groove of the upper pressure plate is b4 = 2mm, the bottom width of the trapezoidal tooth is b5 = 0.85mm, the top width of the tooth is b6 = 0.2mm, and the tooth height is H2 = 4.5mm; close the upper template in the fixing device, and adjust the gap width of the working surface to the required size of 0.2mm by tightening the screws, and fix the gap size.

[0084] (3) Remove the screen from the fixed device, grind the working surface of the screen, and bend the finely processed flat screen into a circular arc shape on a special mold.

Claims

1. A method for processing metal screens for centrifuges, characterized in that, Includes the following steps: 1) Use laser cutting equipment to cut stainless steel sheet of thickness b into steel strips with rectangular cross-sections, and deburr and straighten the steel strips; 2) Position and clamp several steel bars using a fixing device to ensure that the gap size of the screen to be processed meets the design requirements; In step 2), the fixing device includes a lower base plate and an upper pressure plate. The lower base plate is machined with an equilateral trapezoidal groove and equilateral trapezoidal teeth. The bottom width of the trapezoidal groove is b1, which is 2b+c, where c is the screen gap size of the screen to be processed. The bottom width of the trapezoidal teeth is b2, the top width is b3, and the height is H1. The upper pressure plate is also machined with an equilateral trapezoidal groove and equilateral trapezoidal teeth. The bottom width of the trapezoidal groove is b4, the bottom width of the trapezoidal teeth is b5, the top width is b6, and the height is H2. When the upper pressure plate and the lower base plate are combined, the center line of the trapezoidal teeth in the upper pressure plate coincides with the center line of the trapezoidal groove in the lower base plate. The specific process of step 2) is as follows: place the steel bars in the trapezoidal groove of the bottom plate of the fixing device, arrange two steel bars in one trapezoidal groove and attach them to the two sides of the trapezoidal groove respectively, then place the upper pressure plate on the bottom plate so that the two ends of the steel bars are aligned, and tighten the fixing screws of the upper pressure plate and the bottom plate. At this time, the steel bars are distributed in an inverted V shape on both sides of the trapezoidal teeth of the bottom plate. 3) Using laser cladding, a stainless steel coating of width L1 is deposited on the upper end face of the steel strip at a spacing L2 to form a screen blank I; 4) The steel bars are welded together using argon arc welding at a spacing of L2 and a weld length of L1 to form a screen blank II; 5) Machining screen blank I or screen blank II, bending it into shape on a fixed device to obtain the finished product.

2. The processing method for a metal screen for a centrifuge according to claim 1, characterized in that, The specific process of step 3) is as follows: place the fixing device on the laser powder cladding fixture platform, adjust the center line of the coating to be welded and the direction of the welding gun to be traveled to be in the same vertical plane, and adjust the starting position of the welding gun. Then fix the fixing device on the welding machine fixture platform; turn on the laser welding machine, after the first stainless steel coating T1 is welded, adjust the position of the welding gun again, and weld the next stainless steel coating until all the designed stainless steel coatings are welded to form a screen blank I.

3. The processing method for a metal screen for a centrifuge according to claim 1, characterized in that, The specific process of step 4) is as follows: the fixing device is placed on the argon arc welding workbench and fixed, the argon arc welding machine is turned on, and the stainless steel strips are welded and connected according to the designed weld position and length to form a screen blank II.

4. The processing method for a metal screen for a centrifuge according to claim 1, characterized in that, The specific process of step 5) is as follows: First, the working surface of screen blank I or screen blank II is ground and processed to a roughness of less than 1.6 micrometers; then the mounting surface is ground to process the screen thickness to the design size; then the two end faces and two side faces of the screen are milled according to the design size and parallelism and perpendicularity tolerance requirements of the screen to obtain a flat screen; finally, the finely processed flat screen is bent into shape on a special mold to obtain an arc-shaped screen.

5. The processing method for a metal screen for a centrifuge according to claim 1, characterized in that, Step 5) is followed by the following steps: remanufacturing the failed screen. First, the failed screen is leveled, then the gap on the working surface is adjusted to the design size using a fixing device, and the gap size is fixed. Then, the working surface of the flat screen is ground and processed, and the finely processed flat screen is bent into shape on a special mold to obtain an arc-shaped screen.

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