Filter mesh at the inlet of a root vacuum pump

Abstract

Filter mesh at an inlet of a root vacuum pump, wherein the filter mesh device is mainly installed between an air inlet flange on an outside of the root vacuum pump and an air outlet flange of an outer pipe; wherein the filter mesh device is used during start-up and normal operation of the root vacuum pump; wherein the filter mesh device comprises the following: a flange base that is annular in shape; a central part of the flange base that is formed with a through-hole; fluid that flows from the air outlet flange to the air inlet flange through the through-hole; an annular outer edge of the flange base, which projects upwards to be formed with an annular rounding; an inner surface of the flange base formed with a lowered stepped inner annular surface; and a plurality of recesses formed in the stepped inner annular surface; a cross-shaped support rod arranged in the multitude of recesses of the stepped inner annular surface; a filter mesh set which is fixed in the stepped inner ring-shaped surface on the cross-shaped support rod; and wherein the filter mesh set is made of stainless steel; the filter set comprises the following: a first filter net with larger filter passage holes, which is installed on the cross-shaped support rod; the cross-shaped support rod serves to support the first filter net in order to prevent the first filter net from falling down; a second filter screen installed on top of the first filter screen; the filter openings of the first filter screen are larger than those of the second filter screen; wherein the second filter mesh and the first filter mesh are bound together by a multitude of wires; when the second filter mesh needs to be removed, all the wires are loosened to allow for convenient removal of the second filter mesh.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to Roots pumps and, more particularly, to a filter net at the inlet of a Roots vacuum pump. BACKGROUND OF THE INVENTION

[0002] Roots vacuum pumps are widely used in the electricity, semiconductor, solar energy, oil, and food industries, etc. The gaps between the vanes, the vane and the pump chamber, and the vanes and the shaft of the covers are so small that even the smallest dust particles can cause severe clogging and damage to a pump.

[0003] To prevent dust or contaminants from entering the pump casing, filter nets must be installed at the inlet of a Roots pump during start-up and normal operation.

[0004] Conventional filter nets are cumbersome to remove and replace. Furthermore, a filter net is always vulnerable to damage or even complete destruction at the inlet. In current filter nets, the wires of the filter net are welded to the pump flange. However, because the wires are thin and difficult to weld, the cohesion remains weak after welding. Furthermore, wrinkles easily form in the filter nets, which are then sucked into the pump body. To address these deficiencies, the filter net structures must be precisely designed and the welding work must be improved. SUMMARY OF THE INVENTION

[0005] Accordingly, the object of the present invention is to provide a filter net at an inlet of a roots vacuum pump. The present invention has a compact structure and the top and bottom thereof are equipped with O-rings, so that the installation, replacement, and disassembly of the filter net device can be carried out conveniently and quickly. The cross-shaped support rod of the filter net device is buckled into the recess of the flange base and welded thereto without detaching, thereby providing improved protection for the filter net. In the present invention, two-layer filter nets are used, which meet the need for filtering under various operating conditions. The casing of the first filter net 42 is surrounded by a metal sheet.Compared with a general filter net, the first filter net 42 of the present invention is convenient for welding even in more complicated welding processes to prevent the formation of wrinkles due to welding and falling off. BRIEF DESCRIPTION OF THE FIGURES Fig. shows a schematic view depicting the filter net device of the present invention. Fig. shows a schematic view illustrating the connection of the application of the present invention. Fig. shows a schematic view illustrating the connection of the filter network device according to the present invention. Fig. shows a structural view of the filter net device of the present invention. Fig. shows a schematic view depicting the flange base of the present invention. Fig. shows a schematic view illustrating the integration of the filter network device according to the present invention. Fig. shows an application of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0006] To better understand the present invention, it is described in detail below. However, these descriptions and the accompanying drawings are intended only to help those skilled in the art understand the objects, features, and characteristics of the present invention and are not intended to limit the scope and spirit of the present invention, which is defined in the appended claims.

[0007] In the Fig. The filter net is shown at an inlet of a roots vacuum pump according to the present invention. As shown in Fig. As shown, the filter net device 3 is mainly installed between an air inlet flange 6 on an outer side of the roots vacuum pump and an air outlet flange 4 of an external pipe (not shown). The filter net device 3 is used during startup and normal operation of the roots vacuum pump 1 to prevent dust, particles, or contaminants from entering the roots vacuum pump 1. An inner diameter of the filter net device 3 approximately corresponds to the diameter of the air inlet flange 6. For the description of the invention, only a part of the roots vacuum pump 1 is shown, which is not used to limit the scope of the present invention.

[0008] With reference to the Fig. The filter network device 3 of the present invention comprises the following elements: A flange base 31 consists of a ring-shaped structure. A central part of the flange base 31 is provided with a through hole 36. Fluid flows through the through hole 36 from the air outlet flange 4 to the air inlet flange 6. The flange base 31 represents a cylinder with a size of ø 573 mm (diameter) × 10 mm (height). The through hole 36 has a diameter of ø 500 mm, with the Fig. The view shown depicts a cross-sectional view of the flange base 31.

[0009] An annular outer edge of the flange base 31 protrudes upwards and forms an annular curve 41. The annular curve 41 has a height of 3.5 mm and an inner diameter of ø 530 mm.

[0010] An inner side of the flange base 31 is formed with a depressed, stepped inner annular surface 311. A plurality of recesses 351 are formed in the stepped inner annular surface 311.

[0011] A first O-shaped groove 38 is formed in a top surface of the annular roundness 41. The annular ring 41 has a rectangular cross-section for installing a first O-ring 34. An inner diameter of the O-shaped groove 38 is ø 540 mm, and the rectangular cross-section of the annular ring 41 has a size of 8.2 mm × 5 mm.

[0012] A cross-shaped support rod 32 is disposed in the plurality of recesses 351 of the stepped inner annular surface 311. Preferably, four recesses 351 of the stepped inner annular surface 311 are provided, which are evenly spaced along the circumference of the stepped inner annular surface 311 to fix the cross-shaped support rod 32. The function of the cross-shaped support rod 32 is to support and shield the filter net device 3, thereby preventing the filter net device 3 from falling.

[0013] The cross-shaped support rod 32 is formed by four cross-shaped steel plates. Four ends of the cross-shaped support rod 32 are firmly connected and welded to the four recesses 351 in the stepped inner annular surface 311 of the flange base 31. After installation, the height of the cross-shaped support rod 32 is higher than that of the stepped inner annular surface 311 of the flange base 31. The tight engagement and welding arrangement prevents the cross-shaped support rod 32 from falling off.

[0014] Preferably, the cross-sectional size of each steel plate is 5 mm × 15 mm. Preferably, the cross-sectional size of each recess is 35 mm × 5 mm, and the length of the recess is 25 mm.

[0015] A filter net assembly 40 is mounted in the stepped inner annular surface 311 on the cross-shaped support rod 32. The filter net assembly 40 is made of stainless steel 305.

[0016] Referring to Fig. The filter network set 40 comprises the following elements: A first filter net 42 with larger filter holes is mounted on the cross-shaped support rod 32. The cross-shaped support rod 32 serves to support the first filter net 42 and prevent the first filter net 42 from falling off. Preferably, the mesh count of the first filter net 42 is six (six holes per 25.4 mm). The diameter of the first filter net 42 is ø 520 mm and the thickness is 2.5 mm.

[0017] Preferably, the casing of the first filter net 42 is enclosed by a metal sheet. Compared to a conventional filter net, the first filter net 42 of the present invention is suitable for welding with a higher welding combination to prevent the formation of wrinkles due to the welding process and prevent falling off.

[0018] A second filter net 44 is installed on the first filter net 42. The filter holes of the first filter net 42 are larger than those of the second filter net 44. The diameter of the second filter net 44 is 500 mm and the thickness is 0.25 mm. The mesh size of the second filter net 44 is 35 (35 holes per 25.4 mm).

[0019] As in Fig. As shown, the second filter net 44 and the first filter net 42 are connected to each other by a plurality of wires 46. If the second filter net 44 needs to be removed, all wires 46 are loosened to easily remove the second filter net 44. The use of two-layer filter nets 42, 44 can meet the need for different operating states of the vacuum pumps during start-up and normal operation. Fig. This is a partially enlarged view of the filter mesh sets. The sizes and their installation are for descriptive purposes only and do not limit the scope of the present invention. Preferably, the wires 46 are thin steel wires.

[0020] By using tools to detach the wires 46, the second filter net 44 is separated from the first filter net 42. Then, the second filter net 44 is detached from the bottom 311 of the inner circle of the filter net set, leaving only the first filter net 42 for filtering.

[0021] Referring to Fig. The annular outer edge of the flange base 31 is provided with at least one eyelet 33 for convenient removal, so that by holding the eyelet 33, the filter net set 40 can be removed from the air inlet flange 6 and the wires 46 can be detached. Only the first filter net 42 remains and is returned to the air inlet flange 6 for filtering.

[0022] In the present invention, the filter net set 40 is made of stainless steel.

[0023] An upper and lower side of the filter net device 3 are equipped with a first O-ring for sealing.

[0024] In addition, a first O-ring 34 is installed to tightly seal the filter unit 3 and the air outlet flange 4. The first O-ring recess 38 is formed on an upper edge of the annular curve 41.

[0025] A second O-ring 2 is installed between the filter net unit 3 and the air inlet flange 6. A second O-shaped recess 61 is formed in the air inlet flange 6 for installing the second O-ring 2. The sizes of the first O-ring 34 and the second O-ring 2 are ø 540 mm × 7 mm. Preferably, the first O-ring 34 and the second O-ring 2 are made of fluororubber.

[0026] The height of the filter power supply 3 of the present invention is 10 mm.

[0027] A filter net at an inlet of a roots vacuum pump comprises: a flange base which is an annular base; an annular outer edge of the flange base which protrudes with an annular ring; an inner side of the flange base which is formed with a depressed, stepped inner annular surface; a cross-shaped support rod which is arranged in the plurality of recesses of the stepped inner annular surface; a filter net set which is installed in the stepped inner annular surface on the cross-shaped support rod.The filter net set includes a first filter net with larger filter through holes, which is installed on the cross-shaped support rod; the cross-shaped support rod serves to support the first filter net to prevent the first filter net from falling; a second filter net installed on the first filter net; the filter through holes of the first filter net are larger than those of the second filter net.

[0028] Having described the invention, it will be obvious that it may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

[1] A filter net at an inlet of a roots vacuum pump, the filter net device being installed mainly between an air inlet flange on an outer side of the roots vacuum pump and an air outlet flange of an outer pipe; the filter net device being used during start-up and normal operation of the roots vacuum pump; the filter net device comprising: a flange base that is an annular base; a central part of the flange base formed with a through hole; fluid flowing from the air outlet flange to the air inlet flange through the through hole; an annular outer edge of the flange base projecting upward to be formed with an annular curve; an inner surface of the flange base formed with a depressed stepped inner annular surface; and a plurality of recesses formed in the stepped inner annular surface; a cross-shaped support rod disposed in the plurality of recesses of the stepped inner annular surface; a filter net set fixed in the stepped inner annular surface on the cross-shaped support rod; and wherein the filter net set is made of stainless steel; where the filter network set comprises the following: a first filter net with larger filter through holes, which is installed on the cross-shaped support rod; the cross-shaped support rod serves to support the first filter net to prevent the first filter net from falling; a second filter net installed on the first filter net; the filter through holes of the first filter net are larger than those of the second filter net; wherein the second filter net and the first filter net are bound together by a plurality of wires; when the second filter net needs to be removed, all the wires are loosened to conveniently detach the second filter net. [2] The filter net at an inlet of a roots vacuum pump according to claim 1, wherein the flange base is a cylinder having a size of ø 573mm (diameter) × 10mm (height); the through hole has a diameter of ø 500mm, the annular ring has a height of 3.5mm and an inner diameter of ø 530mm. [3] A filter net at an inlet of a roots vacuum pump according to claim 1, wherein a first O-shaped groove is formed in a top surface of the annular ring; the annular ring has a rectangular cross section for installing a first O-ring. [4] The filter net at an inlet of a roots vacuum pump according to claim 3, wherein an inner diameter of the O-shaped groove is ø 540mm and the rectangular cross section of the annular ring has a size of 8.2mm × 5mm. [5] A filter net at an inlet of a roots vacuum pump according to claim 1, wherein there are four recesses of the stepped inner annular surface evenly arranged along the circumference of the stepped inner annular surface for installing the cross-shaped support rod. [6] A filter net at an inlet of a roots vacuum pump according to claim 1, wherein the cross-shaped support rod is formed by four cross-shaped steel plates; four ends of the cross-shaped support rod are fixedly connected and welded to the four recesses in the stepped inner annular surface of the flange base. [7] A filter net at an inlet of a roots vacuum pump according to claim 1, wherein a mesh of the first filter net is six (six holes per 25.4mm); a diameter of the first filter net is ø 520mm with a thickness of 2.5mm; a diameter of the second filter net is ø 500mm with a thickness of 0.25mm; a mesh of the second filter net is 35 (35 holes per 25.4mm). [8] A filter net at an inlet of a roots vacuum pump according to claim 1, wherein the casing of the first filter net is enclosed by a metal sheet. [9] A filter net at an inlet of a roots vacuum pump according to claim 1, wherein the second filter net and the first filter net are tied together by a plurality of wires. [10] A filter net at an inlet of a roots vacuum pump according to claim 1, wherein the first filter net is welded to the stepped inner annular surface. [11] A filter net at an inlet of a roots vacuum pump according to claim 1, wherein the annular outer edge of the flange base is formed with at least one eyelet.

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