Filter screen device for inlet of roots vacuum pump

Abstract

A filter screen device for an inlet of a roots vacuum pump comprises a flange plate base, a filter screen and a filter screen, the bottom of the ring extends inwards to form an inner ring bottom surface; a cross-shaped supporting rod is arranged in a plurality of grooves formed on the bottom surface of the inner ring; a filter screen group is mounted on the bottom surface of the inner ring; the filter screen group comprises a coarse-mesh filter screen which is arranged on the crossed supporting rod; the fine-mesh filter screen is mounted above the coarse-mesh filter screen, and the hole area of the coarse-mesh filter screen is larger than that of the fine-mesh filter screen; wherein the fine-mesh filter screen and the coarse-mesh filter screen are integrated together, and when the fine-mesh filter screen needs to be removed, the fine-mesh filter screen and the coarse-mesh filter screen are separated so as to meet the filtering requirements of different working conditions when the vacuum pump is started and normally runs.

Description

Technical Field

[0001] The utility model relates to a filter screen device, in particular to a filter screen device used for an inlet of a Roots vacuum pump. Background Art

[0002] Roots vacuum pumps are rotary, variable-displacement vacuum pumps without internal compression. They are widely used in industries such as power generation, semiconductors, photovoltaics, petrochemicals, food processing, and smelting. The gaps between the impellers, the radial gaps between the impellers and the pump chamber, and the axial gaps between the impellers and the end caps are very small. Therefore, if dust and debris enter the Roots vacuum pump, they can contaminate and clog it, increasing the risk of wear and damage, reducing pump performance, shortening its service life, and increasing maintenance costs.

[0003] Therefore, when the Roots vacuum pump is started and operating normally, a filter device should be installed at the pump inlet to prevent dust and debris (such as welding slag, etc.) in the pipeline from entering the Roots vacuum pump.

[0004] Traditional inlet filter assemblies are difficult to disassemble and replace. Furthermore, they are prone to damage and detachment. Existing filter assemblies weld the filter wire to the flange base. Due to the thinness of the filter wire, welding is difficult and the weld strength is poor, making it prone to wrinkling, damage, detachment, and being sucked into the pump. To address this issue, the filter assembly structure must be carefully designed, while also improving the weld quality of the filter.

[0005] Therefore, the present invention hopes to provide a new filter device for the inlet of a Roots vacuum pump to solve the above-mentioned defects in the prior art. Utility Model Content

[0006] Therefore, the purpose of the present invention is to solve the above-mentioned problems in the prior art. The present invention proposes a filter device for the inlet of a Roots vacuum pump. The cross-shaped support rod of the filter device is not only stuck in the groove of the flange base, but also welded to the flange base, and will not fall off, which can well support and protect the filter. The filter device adopts a double-layer filter, which can meet the filtering needs of different working conditions during startup and normal operation. The filter device adopts a hemmed filter for its large-pore filter. The sheet metal hemming of the hemmed filter is welded to the flange base. The hemmed filter is easy to weld and has a high weld bonding rate, which can avoid wrinkles caused by welding and falling off caused by weak welds. The filter device has a combination of two unique advantages: a small and thin structure and O-ring sealing on both the upper and lower end faces, which makes the installation, replacement and removal of the filter device simple, convenient and quick.

[0007] To achieve the above-mentioned objectives, the present invention provides a filter device for the inlet of a Roots vacuum pump, wherein the filter device is mainly installed between a gas inlet pipeline flange on the outer plate of a Roots vacuum pump and a gas outlet flange connected to an external gas pipeline; the filter device comprises: a flange base in the form of an annular base, a through hole formed in the center of the flange base, through which fluid can flow from the gas outlet flange into the gas inlet pipeline flange; an annular outer edge of the flange base protrudes upward to form a ring; wherein an inner ring bottom surface extends inward from the bottom of the ring in the flange base; A cross-shaped support rod is configured in a plurality of grooves formed on the inner ring bottom surface of the flange base; a filter screen group is installed on the inner ring bottom surface at the cross-shaped support rod; the filter screen group includes: a coarse mesh filter screen installed on the cross-shaped support rod; a fine mesh filter screen is installed above the coarse mesh filter screen, and the hole area of ​​the coarse mesh filter screen is larger than the hole area of ​​the fine mesh filter screen; wherein the fine mesh filter screen and the coarse mesh filter screen are integrated together, and when the fine mesh filter screen needs to be removed, the fine mesh filter screen and the coarse mesh filter screen are separated to meet the filtering needs of different working conditions when the vacuum pump is started and during normal operation.

[0008] As a further technical solution, the flange base is cylindrical with a size of ø573mm×10mm; the diameter of the through hole is ø500mm; the height of the ring on the flange base is 3.5mm, and the inner diameter of the ring is ø530mm.

[0009] As a further technical solution, a first O-ring groove is formed on the upper edge of the ring, and its cross-section is rectangular, which is used to install a first O-ring; when the gas outlet flange and the gas inlet pipeline flange are directly combined, the O-ring seal is still formed between the joint surfaces.

[0010] As a further technical solution, the inner diameter of the first O-ring groove is ø540 mm, and its cross-section is a rectangular groove of 8.2 mm×5 mm.

[0011] As a further technical solution, the cross-shaped support rod is a cross-shaped support rod, wherein four square grooves for installing the cross-shaped support rod are evenly opened in the circumferential direction of the bottom surface of the inner ring.

[0012] As a further technical solution, the cross-shaped support rod is connected by four steel plates to form a cross shape; the four ends of the cross-shaped support rod are respectively clamped in the four grooves on the inner ring bottom surface of the flange base and welded to the inner ring bottom surface.

[0013] As a further technical solution, the precision of the coarse mesh filter is 6 mesh; the diameter of the coarse mesh filter is ø520mm and the thickness is 2.5mm; the diameter of the fine mesh filter is ø500mm and the thickness is 0.25mm; the precision of the fine mesh filter is 35 mesh.

[0014] As a further technical solution, the coarse-mesh filter is an edge-wrapped filter.

[0015] As a further technical solution, a plurality of wire bodies bundle the fine-mesh filter and the coarse-mesh filter together.

[0016] As a further technical solution, the coarse-mesh filter is welded to the inner ring bottom surface of the ring.

[0017] As a further technical solution, a double-layer filter is used when the machine is just started; when the machine enters normal operation after a period of startup, the fine-mesh filter is removed and the coarse-mesh filter is retained; when the Roots vacuum pump has been running for a period of time and the operating conditions require the filter device to be removed, the gas outlet flange and the gas inlet pipe flange are directly connected with a number of screws, and the elongation of the flexible connection pipe on the gas outlet flange can compensate for the height of the removed filter device.

[0018] The features and advantages of the present invention can be further understood from the following description, which is also referred to with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0020] Figure 1 A schematic diagram showing the connection of the filter device of the present invention;

[0021] Figure 2 A connection diagram showing an application example of the utility model;

[0022] Figure 3 A schematic diagram showing the connection of the filter assembly of the present invention;

[0023] Figure 4 A structural diagram showing the filter assembly of the present invention;

[0024] Figure 5 A cross-sectional view showing the flange base of the present invention;

[0025] Figure 6 A schematic diagram showing the integration of the filter assembly of the present invention;

[0026] Figure 7 Shows application examples of the present invention.

[0027] Description of Reference Numerals

[0028] 1. Outer plate of the Roots vacuum pump; 2. Second O-ring; 3. Filter assembly; 31. Flange base; 311. Bottom of the inner ring; 32. Cross support rod; 33. Ear handle; 34. First O-ring; 351. Groove; 36. Through hole; 38. First O-ring groove; 4. Gas outlet flange; 40. Filter assembly; 41. Ring; 42. Coarse-mesh filter; 44. Fine-mesh filter; 46. Wire; 5. Screw; 6. Gas inlet pipe flange; 61. Second O-ring groove. DETAILED DESCRIPTION

[0029] The structure of the present invention, as well as the effects and advantages it can produce, is now described in detail below with reference to the accompanying drawings, using a preferred embodiment of the present invention.

[0030] Please refer to Figures 1 to 7 As shown, the filter device for the inlet of the Roots vacuum pump of the present invention is shown. Figure 2 As shown, the filter assembly 3 is primarily mounted between a gas inlet flange 6 on the outer plate 1 of a Roots vacuum pump and a gas outlet flange 4 of an external gas pipeline (not shown). This filter assembly 3 prevents dust and debris from entering the pipeline during startup and normal operation. The inner diameter of the filter assembly 3 is equal to the aperture of the gas inlet flange 6. The diagram only shows a portion of the Roots vacuum pump for illustrative purposes.

[0031] like Figure 1 and Figure 3 As shown, the filter device 3 includes:

[0032] A flange base 31 is an annular base with a through hole 36 formed in the middle of the flange base 31. Fluid can flow from the gas outlet flange 4 into the gas inlet pipe flange 6 through the through hole 36. The flange base 31 is cylindrical with a diameter of 573 mm x 10 mm. The diameter of the through hole 36 is 500 mm. Figure 5 A cross-sectional view of the flange base 31 is shown.

[0033] The outer annular edge of the flange base 31 protrudes upward to form a ring 41. The height of the ring 41 on the flange base 31 is 3.5 mm, and the inner diameter of the ring 41 is ø530 mm.

[0034] In the flange base 31 , an inner ring bottom surface 311 extends inward from the bottom of the ring 41 .

[0035] The upper edge of the ring 41 forms a first O-ring groove 38 with a rectangular cross section for mounting a first O-ring 34. The first O-ring groove 38 has an inner diameter of ø540 mm and a cross section of 8.2 mm x 5 mm.

[0036] The four ends of a cross-shaped support rod 32 are positioned within a plurality of grooves 351 formed on the inner ring bottom surface 311 of the flange base 31. Preferably, four square grooves 351 are evenly spaced around the inner ring bottom surface 311 to receive the cross-shaped support rod 32. The cross-shaped support rod 32 supports and protects the filter assembly 3, preventing it from falling and being damaged.

[0037] The cross-shaped support rod 32 is formed by connecting four steel plates to form a cross shape. The steel plates have excellent bending rigidity and large supporting force. The four ends of the cross-shaped support rod 32 are respectively stuck in the four grooves 351 of the inner ring bottom surface 311 of the flange base 31 and welded to the inner ring bottom surface 311. After installation, the cross-shaped support rod 32 must not be higher than the inner ring bottom surface 311 of the flange base 31. This method of both being stuck in the groove and being welded can prevent accidents caused by the cross-shaped support rod 32 falling off.

[0038] The cross-sectional dimensions of the steel plate are preferably 5 mm x 15 mm. The groove 351 is preferably 5 mm x 5 mm, with a length of 25 mm.

[0039] A filter assembly 40 is mounted on the inner ring bottom surface 311 of the cross-shaped support rod 32. The filter assembly 40 is made of 304 stainless steel.

[0040] like Figure 4 As shown, the filter group 40 includes:

[0041] A coarse mesh filter 42 is mounted on the cross-shaped support rods 32. The cross-shaped support rods 32 support and protect the filter 42, preventing it from falling and being damaged. The coarse mesh filter 42 preferably has a 6-mesh precision. The coarse mesh filter 42 has a diameter of ø520 mm and a thickness of 2.5 mm.

[0042] The coarse mesh filter 42 is preferably a wrapped edge filter. Compared with ordinary filter screens, the wrapped edge filter is convenient to weld with sheet metal wrapping and has a high weld bonding rate, which can avoid wrinkles caused by welding and falling off caused by weak welds.

[0043] A fine-mesh filter 44 is mounted above the coarse-mesh filter 42. The pore area of ​​the coarse-mesh filter 42 is larger than that of the fine-mesh filter 44. The fine-mesh filter 44 has a diameter of ø500 mm and a thickness of 0.25 mm. Preferably, the fine-mesh filter 44 has a precision of 35 mesh.

[0044] like Figure 6 As shown, a plurality of wires 46 are used to bundle the fine mesh filter 44 and the coarse mesh filter 42 together. When the fine mesh filter 44 needs to be removed, the wires 46 are untied to conveniently remove the fine mesh filter 44. The double-layer filter combination can meet the filtering needs of different working conditions when the vacuum pump is started and when it is running normally. Figure 6 The diagram is a partial enlarged view of the filter screen, and its size and installation method are for illustration purposes only and are not intended to limit the scope of the present invention. Preferably, the wire 46 is a thin steel wire.

[0045] The wire body 46 can be removed by a tool to separate the fine-mesh filter 44 and the coarse-mesh filter 42 , and the fine-mesh filter 44 can be removed from the inner ring bottom surface 311 by a tool, leaving only the coarse-mesh filter 42 for filtering.

[0046] like Figure 7 As shown, for easy disassembly, the outer edge of the flange base 31 is formed with at least one ear handle 33, and the user can use the ear handle 33 to remove the filter group 40 from the gas inlet pipe flange 6 and remove the wire body 46, leaving only the coarse mesh filter 42 and moving it back into the gas inlet pipe flange 6 for filtering.

[0047] The filter assembly 40 is made of 304 stainless steel with a quenched mesh to reduce corrosion, facilitate cleaning and reuse, and reduce maintenance costs. The coarse-mesh filter 42 is preferably welded to the inner ring bottom surface 311 of the ring 41. The weld between the filter assembly 40 and the inner ring bottom surface 311 must not extend beyond the ring 41 of the flange base 31.

[0048] When the machine is first started, a double-layer filter is used; after a period of time, when the machine enters normal operation, the fine-mesh filter 44 is removed, while the coarse-mesh filter 42 is retained. Depending on the working conditions, the use of a double-layer filter or a single-layer filter can filter the gas evenly, improve the filtration efficiency, reduce air flow resistance, and increase the extraction rate.

[0049] Furthermore, after the Roots vacuum pump 1 has been running for a period of time, if the operating conditions require that the filter device 3 be removed, the gas outlet flange 4 and the gas inlet pipe flange 6 can be directly connected with several screws 5. The elongation of the flexible connection pipe on the gas outlet flange 4 can compensate for the 10mm height of the removed filter device 3. The joint surface between the gas outlet flange 4 and the gas inlet pipe flange 6 is still sealed with an O-ring. Therefore, the removal of the filter device 3 does not affect the installation and use of the system equipment. The filter device 3 is flexible, adaptable, and convenient to use. The several screws are evenly distributed on the ø600mm outer frame of the gas outlet flange 4, and the filter device 3 is clamped between the two. Preferably, the screws are of specification M20. When the filter device 3 is to be replaced, the screws 5 connecting the gas outlet flange 4 and the gas inlet pipe flange 6 are removed, the old filter device 3 is pulled out, the new filter device 3 is inserted, the O-ring seal between the joint surfaces is installed, and the screws 5 are connected and tightened, and then it can be restored to use.

[0050] The upper and lower end surfaces of the filter device 3 are both sealed with O-rings.

[0051] Furthermore, the first O-ring 34 is used to seal between the filter device 3 and the gas outlet flange 4 , and the first O-ring groove 38 is opened on the upper edge of the ring 41 .

[0052] Furthermore, a second O-ring 2 is used to seal the filter assembly 3 against the gas inlet pipe flange 6. A second O-ring groove 61 is formed on the gas inlet pipe flange 6, and the second O-ring 2 is installed in the second O-ring groove 61. The second O-ring 2 and the first O-ring 34 both have a size of ø540 mm x 7 mm and are preferably made of fluororubber.

[0053] The filter device 3 of the present invention has a compact and thin structure and can be made very small in height, which is only 10 mm. The external gas pipeline connected to it is a flexible connection pipeline (not shown in the figure). The extension or contraction of the flexible connection pipeline can exceed the 10 mm height of the filter device 3.

[0054] The advantage of the present invention is that the filter device has a combination of two unique advantages: a compact and thin structure and O-ring sealing on both the upper and lower end faces, which makes the installation, replacement and removal of the filter device simple, convenient and quick. The cross-shaped support rods of the filter device are both stuck in the groove of the flange base and welded to the flange base, and will not fall off, which can well support and protect the filter. The filter device uses a double-layer filter screen as its component, which can meet the filtering needs of different working conditions during startup and normal operation. The filter device uses a hemmed filter screen as its component with large pores. The sheet metal hemming of the hemmed filter screen is welded to the flange base. The hemmed filter screen is easy to weld and has a high weld bonding rate, which can avoid wrinkles caused by welding and shedding caused by weak welds.

[0055] In summary, the user-friendly and thoughtful design of this utility model meets practical needs. Its specific improvements address existing deficiencies and offer significant breakthroughs compared to existing technologies, providing a truly enhanced efficacy that is not easily achieved. This utility model has not been previously published or disclosed in domestic or international literature or on the market, thus complying with patent law requirements.

[0056] The above detailed description is a specific description of a feasible embodiment of the present invention, but the embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the spirit of the present technology should be included in the patent scope of the present invention.

Claims

1. A filter device for the inlet of a Roots vacuum pump, characterized in that: The filter device (3) is installed between a gas inlet pipeline flange (6) of an outer plate (1) of a Roots vacuum pump and a gas outlet flange (4) connected to an external gas pipeline; the filter device (3) comprises: A flange base (31) is an annular base, and a through hole (36) is formed in the middle of the flange base (31). Fluid flows from the gas outlet flange (4) into the gas inlet pipeline flange (6) through the through hole (36); The annular outer edge of the flange base (31) protrudes upward to form a ring (41); In the flange base (31), an inner ring bottom surface (311) extends inward from the bottom of the ring (41); A cross-shaped support rod (32) is disposed in a plurality of grooves (351) formed on the inner ring bottom surface (311) of the flange base (31); A filter assembly (40) is mounted on the inner ring bottom surface (311) at the cross-shaped support rod (32); the filter assembly (40) comprises: A coarse-mesh filter (42) is mounted on the cross-shaped support rod (32); A fine-mesh filter (44) is installed above the coarse-mesh filter (42), and the hole area of ​​the coarse-mesh filter (42) is larger than the hole area of ​​the fine-mesh filter (44); The fine-mesh filter (44) and the coarse-mesh filter (42) are integrated together. When the fine-mesh filter (44) needs to be removed, the fine-mesh filter (44) and the coarse-mesh filter (42) are separated.

2. The filter device for the inlet of a Roots vacuum pump according to claim 1, characterized in that: The flange base (31) is cylindrical with a size of ø573mm×10mm; the diameter of the through hole (36) is ø500mm; the height of the ring (41) on the flange base (31) is 3.5mm, and the inner diameter of the ring (41) is ø530mm.

3. The filter device for the inlet of a Roots vacuum pump according to claim 1, characterized in that: The upper edge of the ring (41) forms a first O-ring groove (38) with a rectangular cross-section for mounting a first O-ring (34); when the gas outlet flange (4) and the gas inlet pipeline flange (6) are directly combined, the O-ring seal is formed between the combined surfaces.

4. The filter device for the inlet of a Roots vacuum pump according to claim 3, characterized in that: The inner diameter of the first O-ring groove (38) is ø540 mm, and its cross section is a rectangular groove of 8.2 mm×5 mm.

5. The filter device for the inlet of a Roots vacuum pump according to claim 1, characterized in that: The cross-shaped support rod (32) is a cross-shaped support rod, wherein four square grooves (351) for installing the cross-shaped support rod (32) are evenly provided in the circumferential direction of the inner ring bottom surface (311).

6. The filter device for the inlet of a Roots vacuum pump according to claim 1, characterized in that: The cross-shaped support rod (32) is formed by connecting four steel plates to form a cross shape; the four ends of the cross-shaped support rod (32) are respectively clamped in the four grooves (351) of the inner ring bottom surface (311) of the flange base (31) and welded to the inner ring bottom surface (311).

7. The filter screen device for the inlet of a Roots vacuum pump according to claim 1, characterized in that: The coarse mesh filter (42) has a precision of 6 meshes; the coarse mesh filter (42) has a diameter of ø520 mm and a thickness of 2.5 mm; the fine mesh filter (44) has a diameter of ø500 mm and a thickness of 0.25 mm; the fine mesh filter (44) has a precision of 35 meshes.

8. The filter device for the inlet of a Roots vacuum pump according to claim 1, characterized in that: The coarse mesh filter (42) is an edge-wrapped filter.

9. The filter screen device for the inlet of a Roots vacuum pump according to claim 1, characterized in that: A plurality of wire bodies (46) bundle the fine-mesh filter (44) and the coarse-mesh filter (42) together.

10. The filter device for the inlet of a Roots vacuum pump according to claim 1, characterized in that: The coarse-mesh filter (42) is welded to the inner ring bottom surface (311) of the ring (41).

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