Sock filter inspection equipment, sock filter inspection device, and sock filter inspection method

Abstract

To provide an inspection device, inspection apparatus, and inspection method for reliably and easily performing leak testing on long, cylindrical sock filters installed horizontally along the ceiling surface of clean rooms and the like. [Solution] An inspection instrument comprising an arc-shaped probe in which a plurality of suction cells are arranged in a circumferential direction. The suction cells have a suction cell partitioned by a pair of circumferential walls that are spaced apart from each other and facing each other in the circumferential direction, a pair of axial walls that are spaced apart from each other and facing each other in the axial direction, and an outer diameter side wall that closes the outer diameter side in the radial direction.

Description

Technical Field

[0001] The present disclosure relates to an inspection instrument for a sock filter, an inspection apparatus for a sock filter, and an inspection method for a sock filter.

Background Art

[0002] An inspection apparatus for inspecting the performance of an air filter attached to a clean room or the like is known. As this type of technology, Patent Document 1 discloses an inspection apparatus including a mask that can be adhered to a ceiling surface while surrounding the lower surface of an air filter, a probe located within the mask, a traverse mechanism and a lifting mechanism for moving the probe to a predetermined position, and a motor or the like. The inspection apparatus of Patent Document 1 has a set of the aforementioned mask, probe, etc. mounted on a mobile cart.

[0003] Patent Document 2 discloses a leak inspection support apparatus that, when performing a leak inspection of a filter installed on a ceiling or side wall surface, instructs an operator by an image projected onto the filter surface at the position where the probe should be moved. According to the inspection support apparatus of Patent Document 2, even when an operator holds the probe by hand and approaches the probe to a filter located at a distant position such as a ceiling to perform an inspection, the probe can be accurately operated. The probe has a form having a funnel-shaped suction port and a pipe connected to the lower part of the suction port.

[0004] On the other hand, as an air supply duct installed in a clean room, a long cylindrical filter with a closed tip, called a sock duct or a sock filter, has been proposed. Patent Document 3 discloses a clean room including a porous diffusion film provided in a ceiling portion and a sock duct that extends downward from the porous diffusion film and is disposed surrounding production equipment installed in the clean room.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] In cleanrooms, leak testing is performed on installed filters. Conventional testing equipment can easily inspect flat filters installed on ceilings and side walls. However, it has been considered difficult to properly and easily inspect long cylindrical sock filters installed horizontally along the ceiling using conventional equipment. In light of this situation, one of the purposes of this disclosure is to provide testing equipment, testing apparatus, and testing method for reliably and easily performing leak testing on long cylindrical sock filters installed horizontally along the ceiling of cleanrooms and the like. [Means for solving the problem]

[0007] A sock filter inspection instrument according to this disclosure comprises an arc-shaped probe in which a plurality of suction cells are arranged circumferentially. Each suction cell is demarcated by a pair of circumferential walls spaced apart from each other and facing each other in the circumferential direction, a pair of axial walls spaced apart from each other and facing each other in the axial direction, and an outer diameter side wall that closes the radial outer diameter side. [Effects of the Invention]

[0008] An inspection device, inspection apparatus, and inspection method are provided for reliably and easily performing leak testing on long, cylindrical sock filters installed horizontally along the ceiling surface. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is an explanatory diagram of an inspection apparatus and inspection method according to an embodiment. [Figure 2]Figure 2 is an explanatory diagram of an inspection device according to an embodiment. [Figure 3] Figure 3 is a magnified view of a part of the inspection equipment shown in Figure 2. [Figure 4] Figure 4 is an explanatory diagram of an inspection device according to an embodiment. [Modes for carrying out the invention]

[0010] [Summary of the Embodiment] First, embodiments of the inspection instruments, inspection devices, and inspection methods relating to this disclosure will be listed and described. A sock filter inspection instrument according to this disclosure comprises an arc-shaped probe in which a plurality of suction cells are arranged circumferentially. Each of the suction cells is demarcated by a pair of circumferential walls spaced apart from each other in the circumferential direction, a pair of axial walls spaced apart from each other in the axial direction, and an outer diameter side wall that closes the radial outer diameter side.

[0011] Conventional devices for inspecting filters installed in cleanrooms and similar environments are known. These inspection devices are designed to reliably and easily inspect flat filters installed on ceilings and side walls. On the other hand, a new form of cleanroom has been proposed, in which long, cylindrical sock filters are installed along the ceiling of the cleanroom. In order to put such a cleanroom into practical use, leak testing of the sock filters is necessary, but it has been found that conventional inspection devices have difficulty uniformly and easily scanning the surface of sock filters because they have a cylindrical surface. Under these circumstances, research has been conducted on inspection instruments suitable for inspecting sock filters.

[0012] The inspection device according to this disclosure comprises an arc-shaped probe capable of surrounding the outer circumference of a sock filter. The probe has a plurality of suction cells arranged in the circumferential direction, and each suction cell is partitioned by a pair of circumferential walls, a pair of axial walls, and an outer diameter side wall. According to the inspection device according to this disclosure, the suction cells of the probe can be positioned along the outer circumference of the sock filter, enabling reliable and easy leak testing of the sock filter. Furthermore, by setting the suction cells to a predetermined size, it becomes possible to perform filter performance testing in accordance with public standards (e.g., JIS B9927, ISO14644-3:2019).

[0013] In the inspection device described above, the suction cell may have a tubular portion that protrudes outward from the outer diameter side wall. By providing a tubular portion on the outer diameter side wall of each suction cell, particle measurement can be reliably performed in a probe having multiple suction cells.

[0014] In the aforementioned inspection device, the probe may have a curved shape with a portion missing. This shape makes it easy to attach the probe to a sock filter suspended from the ceiling, thereby facilitating leak testing.

[0015] The sock filter inspection apparatus according to this disclosure comprises a trolley, a measuring device installed on the trolley, an inspection instrument for the sock filter, and a flexible tube connecting the inspection instrument and the measuring device. According to the inspection apparatus according to this disclosure, leak inspections can be performed more easily because the trolley can be moved according to the measurement location.

[0016] In the sock filter inspection apparatus described above, the inspection instrument has a support part that connects to the probe, and the support part may be fixed to the trolley. With this configuration, when the trolley is moved, the inspection instrument moves along with the trolley, so the surface of the sock filter can be reliably scanned and inspected by moving the trolley along the sock filter.

[0017] In the inspection apparatus for the sock filter, the inspection instrument has a support portion connected to the probe, and the support portion may be held by a rail installed on the ceiling. According to such a configuration, the inspection instrument can be suspended and moved along the rail to scan the surface of the sock filter for inspection.

[0018] The inspection method for the sock filter according to the present disclosure is a method for inspecting the sock filter using the inspection instrument, including a preparation step of arranging the inspection instrument so that the probe in the inspection instrument surrounds the outer periphery of the sock filter to be inspected, and an inspection step of moving the inspection instrument along the axial direction of the sock filter while performing leak confirmation. According to this inspection method, the outer peripheral surface of the sock filter can be reliably scanned, and leak inspection can be performed reliably and easily.

[0019] In the inspection method, in the inspection step, leak confirmation can be performed simultaneously for two or more of the plurality of suction cells provided in the inspection instrument. According to the inspection instrument according to the present disclosure, inspections can be performed at a plurality of locations simultaneously, and the inspection can be performed more quickly.

[0020] The inspection method according to the present disclosure is a method for inspecting a sock filter using an inspection apparatus for a sock filter including a cart, a measuring device installed on the cart, an inspection instrument for the sock filter, and a flexible tube connecting between the inspection instrument and the measuring device. The inspection method includes a preparation step of arranging the inspection instrument so that the probe in the inspection instrument surrounds the outer periphery of the sock filter to be inspected, and an inspection step of moving the inspection instrument along the axial direction of the sock filter while performing leak confirmation. In the inspection step, the cart can run on a rail laid in parallel with the sock filter. By the cart running on the rail, the cart can be reliably moved along the sock filter for inspection.

[0021] In the inspection method described above, the inspection instrument may have a support portion connected to the probe, the support portion may be fixed to the trolley, and in the inspection process, the inspection instrument may be supported by the trolley and move integrally with the trolley. In leak testing, if the probe comes into contact with the filter to be inspected, the filter may be damaged and its performance may be impaired. In this regard, according to the inspection method of this disclosure, the inspection can be performed while holding the inspection instrument in an appropriate position relative to the sock filter.

[0022] In the inspection method described above, the inspection instrument has a support part connected to the probe, the support part is held on a rail installed on the ceiling, and in the inspection process, the inspection instrument moves along the rail installed on the ceiling. By suspending the inspection instrument from the ceiling and making it movable along a rail installed on the ceiling, it becomes easier to hold the inspection instrument in the appropriate position relative to the sock filter.

[0023] [Specific examples of embodiments] Next, an example of a specific embodiment of the inspection instrument and inspection apparatus relating to this disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0024] Figure 1 is an explanatory diagram of the inspection apparatus and inspection method according to the present disclosure. Referring to Figure 1, the inspection apparatus 1 is an apparatus used to perform leak testing inside a cleanroom 800 in which a sock filter 200 is installed. The inspection apparatus 1 includes a trolley 50, a measuring device 60 mounted on the trolley 50, and an inspection instrument 10 supported and fixed to the trolley 50. The measuring device 60 is typically a particle counter and also includes devices associated with the particle counter (e.g., a suction pump). The inspection apparatus 1 may also include various devices such as a thermometer and a timer.

[0025] Cleanroom 800 is equipped with rails 300 on the ceiling, from which sock filters 200 are suspended. The sock filters 200 are fixed to the ceiling via suspension hooks 310. When the cleanroom is in operation, air is supplied from duct 500 to the sock filters 200, causing the sock filters 200 to expand into a cylindrical shape. Note that "cylindrical" does not only mean that the cross-section of the sock filter is perfectly circular, but also includes cases where the cross-section is elliptical, teardrop-shaped, or otherwise imperfectly circular. Dust and fine particles in the air are filtered by the sock filters 200, and clean air flows out from the surface of the sock filters 200.

[0026] The specific dimensions of the sock filter 200 are not particularly limited, but for example, the diameter when air is ventilated (inflated) may be about 100 mm to 700 mm, and the length in the longitudinal direction may be about 2 m to 30 m. Typically, it may be about 300 mm in diameter and 10 m in length. The sock filter 200 may be a porous membrane filter made of fibers. The material of the membrane filter is not particularly limited and examples include nonwoven fabric, woven fabric, porous synthetic resin membrane, etc. Depending on the required cleanliness class, electret nonwoven fabric may be selected. It is preferable to be composed of a porous filter material made of PTFE with high dust removal performance and low pressure loss. The sock filter may have a double membrane structure or a single membrane structure, and is not particularly limited.

[0027] The inspection device 10 is supported and fixed to the trolley 50 via a support rod 20. The inspection device 10 is connected to the measuring device 60 via a flexible tube 40. The air collected by the inspection device 10 is introduced to the measuring device 60 through the flexible tube 40, and particle measurement is performed. The flexible tube 40 may be a hose attached to a particle counter, and is not particularly limited as long as it is configured to transport the sampled air.

[0028] A rail 70 is installed on the floor of the cleanroom 800, extending parallel to the axial direction of the sock filter 200, and the trolley 50 travels along the rail 70. The rail 70 may be fixed to the floor of the cleanroom 800, or it may be laid temporarily when inspection is performed. The trolley 50 may be equipped with a running device for automatic movement, or it may be moved by an operator.

[0029] An example of an inspection method for an air filter (sock filter 200) using inspection device 1 will be explained with reference to Figure 1. First, install the sock filter 200 in cleanroom 800. Air filter inspections may be performed initially after the sock filter 200 is installed, or periodically or on an ad-hoc basis while the sock filter 200 is in continuous use.

[0030] The sock filter 200 includes a cylindrical filter body 210 and a suspension belt 220. The inspection device 10 is installed so as to surround the outer circumference of the filter body 210. The inspection device 10 has an arc-shaped probe, but by omitting a part of the arc of the probe, it is possible to move the inspection device 10 continuously in the longitudinal direction (axial direction) of the sock filter 200 without interfering with the suspension belt 220 of the sock filter 200. The surface of the sock filter 200 is scanned while moving the trolley 50 equipped with the inspection device 10 along the rail 70 at a constant speed, and the leak is measured by taking measurements with the measuring device 60. The scanning speed is not particularly limited, but for example it can be 50 mm / second. Leak measurement can be performed under known conditions or by applying known conditions. In addition, although the trolley 50 is shown running on the rail 70 in the example shown in Figure 1, leak measurement may also be performed by methods such as a person pushing the trolley 50 or a person carrying the measuring device 60.

[0031] The probe of the inspection device 10 is equipped with multiple suction cells, as described later, and leak measurements can be performed for each suction cell. Since the suction cells are positioned to surround the outer circumference of the sock filter, it is possible to perform a leak inspection of the entire surface of the sock filter by taking measurements for all of the suction cells. A flexible tube 40 is connected to the location corresponding to the suction cell to be measured, and the measurement is performed. It is also preferable to measure particles for multiple suction cells simultaneously. In the example in Figure 1, particle measurements are taken for two suction cells simultaneously. Performing measurements at multiple locations simultaneously can shorten the inspection time. In addition, by connecting the flexible tube 40 symmetrically to the inspection device, the difference in load between the left and right sides can be reduced, and unintended shaking of the inspection device can be suppressed.

[0032] Figure 2 is an explanatory diagram of an inspection instrument 10, which is an example of an inspection instrument according to this disclosure. The inspection instrument 10 has a probe 11 and a support rod 20. The probe 11 has an overall arc shape, and a plurality of suction cells 17 are arranged in a line in the circumferential direction. The probe 11 has a U-shaped cross section perpendicular to the circumferential direction, and has an outer wall with an opening on the inner diameter side and partition walls that divide the suction cells 17. That is, each suction cell 17 is separated by a pair of circumferential walls 13, 13 that are spaced apart from each other and facing each other in the circumferential direction, a pair of axial walls 14, 14 that are spaced apart from each other and facing each other in the axial direction, and an outer diameter side wall 15 that closes the outer diameter side in the radial direction. Adjacent suction cells 17 share a circumferential wall 13.

[0033] The inspection device 10 shown in Figure 2 has 16 suction cells 17, but the number of suction cells provided on the inspection device is not limited to this and can be changed depending on the diameter of the probe 11. Each of the suction cells 17 has a tube portion 12 that protrudes radially outward from the outer diameter side wall 15. The tube portion 12 is, for example, a rigid hollow tube with a hole diameter of about 1 to 3 mm. A tube portion 12 is provided for each of the suction cells 17. That is, the probe 11 has multiple tube portions 12 (the same number of tube portions 12 as the suction cells 17) that protrude radially. The tube portions 12 shown in Figure 2 are in a straight line shape, but the tube portions 12 may be straight or may have bent sections. The multiple tube portions 12 provided on the probe 11 may all be the same shape or may have different shapes.

[0034] As mentioned above, the probe 11 has a circular arc shape with a portion missing. The central angle of the inspection instrument 10 shown in Figure 2 is approximately 320°. However, the shape of the arc is not limited to this. For example, the probe 11 may be a semicircle or a quarter-circle. It is preferable that the central angle of the arc of the probe 11 is 180° or more.

[0035] Figure 3 is an enlarged view of a part of the inspection device 10 shown in Figure 2. As an example of the specific dimensions of the inspection device 10, the axial width W1 of the suction cell 17 can be, for example, about 10 mm. The radial width W2 of the suction cell 17 can be, for example, about 18 mm. The circumferential width of the suction cell 17 can be, for example, about 80 mm. By adopting this configuration, a suction cell conforming to the suction probe specified in official standards (e.g., ISO 14644-3:2019) can be constructed.

[0036] When performing a leak test on a filter, a flexible tube 40 is attached to the tube section 12 provided on the probe 11, but a connector 45 may be attached between the tube section 12 and the flexible tube 40. By using a connector 45 made of a harder material than the flexible tube, the flexible tube 40 can be prevented from bending. In particular, when measuring a suction cell located above horizontal, if the flexible tube is connected to the tube section and allowed to hang down, there is a risk of the tube bending. In such cases, it is preferable to use a connector.

[0037] The material of the inspection device 10 is not particularly limited as long as it does not impair the accuracy of the leak measurement, and may be made of steel such as stainless steel or resin. The inspection device 10 shown in Figure 2 is equipped with a support rod 20, but the support rod 20 is not an essential component, and the device may be configured without a support rod 20.

[0038] Figure 4 is an explanatory diagram of another embodiment of the inspection device 10 according to this disclosure. While the inspection device 10 shown in Figure 1 is supported by a support rod 20, the inspection device 10 in Figure 4 is supported by being suspended from the ceiling by a suspension device 35.

[0039] Referring to Figure 4, the inspection device 10 is positioned to surround the outer circumference of the sock filter 200, which is fixed to the duct 500 in the cleanroom. The sock filter 200 includes a cylindrical filter body 210 and a suspension belt 220. The suspension belt 220 is attached to the filter body 210 over substantially its entire axial length. The filter body 210 and the suspension belt 220 are integrated. Grommets 222 are formed in the suspension belt 220 at regular intervals, and suspension hooks 310 are attached to the grommets 222. The suspension hooks 310 are attached to a rail 300 fixed to the ceiling. The suspension hooks 310 may be movable along the rail 300 or may be fixed to the rail 300. A pair of rails 31 and 32 are fixed to the ceiling parallel to the rail 300, flanking the rail 300. Rails 300, 31, and 32 may be specialized components fixed to the ceiling of the cleanroom, or they may be part of the structural materials of the cleanroom.

[0040] The inspection device 10 is suspended and supported via bifurcated suspension devices 35 installed on each of a pair of rails 31 and 32 fixed to the ceiling. The inspection device 10 has a tubular section 12 that protrudes radially outward. The inspection device 10 has a plurality of suction cells 17 (see Figure 2), and a flexible tube 40 is attached to the tubular section corresponding to the suction cell to be measured. The flexible tube 40 is connected to the measuring device 60 (see Figure 1). When the inspection device 10 is suspended from the ceiling, it is possible to hold the inspection device 10 more stably and perform the inspection while maintaining an appropriate distance between the sock filter 200 and the inspection device 10.

[0041] As shown in Figure 4, leak testing is performed by scanning the sock filter 200 while moving the inspection instrument 10 in the direction of the arrow. There are no particular restrictions on the number of inspection instruments 10 installed on the sock filter 200. There may be one inspection instrument 10 or two or more installed on the sock filter 200.

[0042] In the configuration shown in Figure 4, the suspension devices 35 are attached to both the left and right sides of the probe 11. The suspension devices 35 are bifurcated and connected to two locations on the front and back sides in the axial direction of the probe 11. The specific shape of the suspension devices 35 is not limited to this, and it may also be a shape in which each of the left and right sides of the probe 11 is supported by a single member. By adopting the bifurcated suspension devices 35, the inspection instrument 10 is held more stably, so that leak testing can be reliably performed while maintaining an appropriate clearance between the probe 11 and the filter body 210.

[0043] The embodiments disclosed herein should be understood in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of Symbols]

[0044] 1 Inspection device, 10 Inspection instrument, 11 Probe, 12 Pipe section, 13 Circumferential wall, 14 Axial wall, 15 Outer diameter side wall, 17 Suction cell, 20 Support rod, 31, 32, 70, 300 Rail, 35 Lifting device, 40 Flexible tube, 45 Connector, 50 Trolley, 60 Measuring device, 200 Sock filter, 210 Filter body, 220 Lifting belt, 222 Grommet hole, 310 Hanging hook, 500 Duct, 800 Cleanroom.

Claims

1. The probe is an arc-shaped probe with multiple suction cells arranged in a circumferential direction. Each of the aforementioned suction cells is A pair of circumferential walls that are separated from each other and face each other in the circumferential direction, A pair of axial walls that are separated from each other in the axial direction and face each other, An outer diameter side wall that closes the outer diameter side in the radial direction, A sock filter inspection device partitioned by a compartment.

2. The suction cell has a tubular portion that protrudes outward from the outer diameter side wall, The inspection device for a sock filter as described in claim 1.

3. The aforementioned probe has an arc shape with a portion missing. An inspection device for a sock filter according to claim 1 or claim 2.

4. A trolley and A measuring device installed on the trolley, An inspection device for a sock filter according to claim 1 or claim 2, A flexible tube connecting the inspection instrument and the measuring device, Equipped with, A testing device for sock filters.

5. The inspection device has a support part that connects to the probe, and the support part is fixed to the trolley. The inspection apparatus for a sock filter according to claim 4.

6. The inspection device has a support part that connects to the probe, and the support part is held on a rail installed on the ceiling. The inspection apparatus for a sock filter according to claim 4.

7. A method for inspecting a sock filter using the inspection instrument described in claim 1 or claim 2, A preparation step of positioning the inspection device such that the probe in the inspection device surrounds the outer circumference of the sock filter to be inspected, A method for inspecting a sock filter, comprising the step of checking for leaks while moving the inspection instrument along the axial direction of the sock filter.

8. In the inspection process, leak checks are performed simultaneously on two or more of the multiple suction cells provided in the inspection device. A method for inspecting a sock filter according to claim 7.

9. A trolley and A measuring device installed on the trolley, An inspection device for a sock filter according to claim 1 or claim 2, A flexible tube connecting the inspection instrument and the measuring device, A method for inspecting a sock filter using a sock filter inspection device equipped with the following: A preparation step of positioning the inspection device such that the probe in the inspection device surrounds the outer circumference of the sock filter to be inspected, The inspection step includes performing a leak check while moving the inspection instrument along the axial direction of the sock filter, In the inspection process, the trolley travels on rails laid parallel to the sock filter. How to inspect a sock filter.

10. The inspection device has a support part that connects to the probe, and the support part is fixed to the trolley. In the inspection process, the inspection instrument is supported by the trolley and moves integrally with the trolley. A method for inspecting a sock filter according to claim 9.

11. The inspection device has a support part that connects to the probe, and the support part is held on a rail installed on the ceiling. In the inspection process, the inspection device moves along the rail installed on the ceiling. A method for inspecting a sock filter according to claim 9.

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