Inspection instrument for sock filter, inspection device for sock filter, and inspection method for sock filter

Abstract

To provide an inspection instrument, an inspection device, and an inspection method for reliably and easily performing a leak inspection of a long cylindrical sock filter installed horizontally along the ceiling surface of a clean room or the like. **Solution**: An inspection instrument including an arcuate probe in which a plurality of suction cells are arranged side by side in the circumferential direction. The suction cell has a suction cell defined by a pair of circumferential walls facing each other with a space therebetween in the circumferential direction, a pair of axial walls facing each other with a space therebetween in the axial direction, and an outer diameter side wall closing 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] There is known an inspection apparatus for inspecting the performance of an air filter attached to a clean room or the like. As this type of technology, Patent Document 1 discloses an inspection apparatus including a mask that can be brought into close contact with 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, a motor, and the like. The inspection apparatus of Patent Document 1 has a set of the foregoing mask, probe, etc. mounted on a moving carriage.

[0003] Patent Document 2 discloses a leak inspection support apparatus that, when performing a leak inspection of a filter installed on a ceiling or a side wall surface, instructs an operator by an image in which the position where the operator should move a probe is projected onto the filter surface. According to the inspection support apparatus of Patent Document 2, even when the 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 membrane provided in a ceiling portion and a sock duct that extends downward from the porous diffusion membrane and surrounds production equipment installed in the clean room.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] In a clean room, leak inspection of installed filters is performed. According to conventional inspection devices, it is possible to easily inspect flat filters installed on the ceiling surface or side wall surface. However, it has been considered difficult to appropriately and easily inspect a long cylindrical sock filter installed horizontally along the ceiling surface with a conventional device. In view of this situation, one of the purposes of the present disclosure is to provide an inspection instrument, an inspection device, and an inspection method for reliably and easily performing leak inspection of a long cylindrical sock filter installed horizontally along the ceiling surface of a clean room or the like. [Means for Solving the Problems]

[0007] The inspection instrument for a sock filter according to the present disclosure includes an arc-shaped probe in which a plurality of suction cells are arranged side by side in the circumferential direction. Each of the suction cells is partitioned by a pair of circumferential walls facing each other with a space therebetween in the circumferential direction, a pair of axial walls facing each other with a space therebetween in the axial direction, and an outer diameter side wall that closes the outer diameter side in the radial direction. [Effects of the Invention]

[0008] An inspection instrument, an inspection device, and an inspection method for reliably and easily performing leak inspection of a long cylindrical sock filter installed horizontally along the ceiling surface are provided. [Brief Description of the Drawings]

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0010] [Overview of the Embodiment] First, embodiments of an inspection instrument, an inspection device, and an inspection method according to the present disclosure will be listed and described. An inspection instrument for a sock filter according to the present disclosure includes an arcuate probe in which a plurality of suction cells are arranged side by side in the circumferential direction. Each of the suction cells is defined by a pair of circumferential walls that face each other and are spaced apart in the circumferential direction, a pair of axial walls that face each other and are spaced apart in the axial direction, and an outer diameter side wall that closes the outer diameter side in the radial direction.

[0011] Conventionally, devices for inspecting filters installed in a clean room or the like are known. These inspection devices are designed to reliably and easily inspect planar filters installed on the ceiling or side wall surfaces. On the other hand, as a new form of clean room, a proposal has been made to install a long cylindrical sock filter along the ceiling in the clean room. In the practical implementation of such a clean room, a leak inspection of the sock filter is required. However, since the sock filter has a cylindrical surface, it has been found that it is difficult to uniformly and easily scan the surface of the sock filter with a conventional inspection device. Under this situation, studies have been advanced on an inspection instrument suitable for inspecting sock filters.

[0012] The inspection instrument according to the present disclosure includes an arcuate probe that can surround the outer periphery of the sock filter. The probe has a plurality of suction cells arranged in the circumferential direction, and each of the suction cells is defined by a pair of circumferential walls, a pair of axial walls, and an outer diameter side wall. According to the inspection instrument of the present disclosure, the suction cells of the probe can be positioned along the outer periphery of the sock filter, and the leak test of the sock filter can be performed reliably and easily. In addition, by making the suction cells a predetermined size, it becomes possible to perform a performance test of a filter compliant with public standards (for example, JIS B9927, ISO14644-3:2019).

[0013] In the inspection instrument, the suction cell may have a pipe portion protruding outward from the outer diameter side wall. By providing a pipe portion on the outer diameter side wall of each of the suction cells, it is possible to reliably measure particles in a probe having a plurality of suction cells.

[0014] In the inspection instrument, the probe may have an arcuate shape with a part missing. By adopting such a form, it becomes possible to easily attach the probe to a sock filter suspended from the ceiling, and the leak inspection can be performed more easily.

[0015] The inspection apparatus for a sock filter according to the present disclosure includes a carriage, a measuring device installed on the carriage, an inspection instrument for the sock filter, and a flexible tube connecting between the inspection instrument and the measuring device. According to the inspection apparatus of the present disclosure, since the leak inspection can be carried out while moving the carriage according to the measurement location, the leak inspection can be performed more easily.

[0016] 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 fixed to the carriage. According to such a form, when the carriage is moved, the inspection instrument also moves together with the carriage. Therefore, by moving the carriage along the sock filter, the surface of the sock filter can be reliably scanned and inspected.

[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 and inspect the surface of the sock filter.

[0018] The inspection method for the sock filter according to the present disclosure is a method for inspecting a 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 at a plurality of locations can be performed 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 running the cart on the rail, the cart can be reliably moved along the sock filter, and the inspection can be performed.

[0021] In the inspection method, the inspection instrument has a support portion connected to the probe, the support portion is fixed to the cart, and in the inspection process, the inspection instrument can be supported by the cart and move integrally with the cart. In leak inspection, when the probe contacts the filter to be inspected, there is a risk of damaging the filter and impairing its performance. In this regard, according to the inspection method according to the present disclosure, the inspection can be performed while holding the inspection instrument at an appropriate position with respect to the sock filter.

[0022] In the inspection method, the inspection instrument has a support portion connected to the probe, the support portion is held by a rail installed on the ceiling, and in the inspection process, the inspection instrument can move along the rail installed on the ceiling. By suspending the inspection instrument from the ceiling and making it movable along the rail installed on the ceiling, it becomes easier to hold the inspection instrument at an appropriate position with respect to the sock filter.

[0023] [Specific Example of Embodiment] Next, an example of a specific embodiment of the inspection instrument and inspection device according to the present 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 the description thereof will not be repeated.

[0024] FIG. 1 is an explanatory diagram of the inspection device and inspection method according to the present disclosure. Referring to FIG. 1, the inspection device 1 is a device used for performing a leak inspection in a clean room 800 where a sock filter 200 is installed. The inspection device 1 includes a cart 50, a measuring device 60 placed on the cart 50, and an inspection instrument 10 supported and fixed to the cart 50. The measuring device 60 is typically a particle counter and also includes devices (such as a suction pump etc.) associated with the particle counter. Further, the inspection device 1 may include various devices such as a thermometer and a timer.

[0025] The clean room 800 is equipped with a rail 300 on the ceiling surface, and a sock filter 200 is suspended from the rail 300. The sock filter 200 is fixed to the ceiling via a suspension hook 310. When the clean room is in operation, air is sent from the duct 500 to the sock filter 200, and the sock filter 200 assumes a shape that bulges into a cylindrical shape. Note that the cylindrical shape is not limited to the case where the cross-section of the sock filter is a perfect circle, but also includes cases where the cross-section is an elliptical shape, a teardrop shape, or other imperfect circular shapes. Dust and fine particles contained in the air are filtered by the sock filter 200, and normal air flows out from the surface of the sock filter 200.

[0026] The specific dimensions of the sock filter 200 are not particularly limited. For example, the diameter during ventilation (bulged state) may be about 100 mm to 700 mm, and the length in the longitudinal direction may be about 2 m to 30 m. Typically, the diameter may be about 300 mm and the length may be about 10 m. The sock filter 200 may be a porous membrane filter made of fiber. The material of the membrane filter is not particularly limited, and examples include non-woven fabric, woven fabric, porous synthetic resin film, etc. Depending on the required cleanliness class, an electret non-woven fabric may be selected. It is preferably composed of a porous filter medium 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 instrument 10 is supported and fixed to the trolley 50 via the support rod 20. The inspection instrument 10 is connected to the measuring device 60 via the flexible tube 40. The air collected by the inspection instrument 10 is introduced into 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 can transfer the sampled air.

[0028] On the floor surface of the clean room 800, a rail 70 extending parallel to the axial direction of the sock filter 200 is installed, and the cart 50 travels along the rail 70. The rail 70 may be fixed to the floor surface of the clean room 800, or may be temporarily laid when inspections are carried out. The cart 50 may be equipped with a traveling device and travel automatically, or may be moved by an operator.

[0029] An example of a method for inspecting an air filter (sock filter 200) using the inspection device 1 will be described with reference to FIG. 1. First, the sock filter 200 is installed in the clean room 800. The inspection of the air filter may be carried out at the initial installation of the sock filter 200, or may be carried out regularly or temporarily during the continued use of the sock filter 200.

[0030] The sock filter 200 includes a cylindrical filter body 210 and a suspension belt 220. The inspection instrument 10 is installed so as to surround the outer periphery of the filter body 210. Although the inspection instrument 10 has an arc-shaped probe, by forming a part of the arc of the probe missing, the inspection instrument 10 can be continuously moved in the longitudinal direction (axial direction) of the sock filter 200 without interfering with the suspension belt 220 of the sock filter 200. While moving the cart 50 equipped with the inspection instrument 10 along the rail 70 at a constant speed, the surface of the sock filter 200 is scanned, and by measuring with the measuring device 60, the leak is measured. The scanning speed is not particularly limited, but can be, for example, 50 mm / second. The leak measurement can be carried out under known conditions or by applying known conditions. Also, in the example shown in FIG. 1, the cart 50 travels on the rail 70, but the leak measurement may also be carried out by methods such as a person pushing the cart 50 to move it or a person holding the measuring device 60 and moving.

[0031] The probe of the inspection instrument 10 is provided with a plurality of suction cells as described later, and leak measurement can be performed for each suction cell. Since the suction cells are positioned so as to surround the outer periphery of the sock filter, by performing measurements for all the suction cells, it becomes possible to perform a leak inspection of the entire surface of the sock filter. A soft tube 40 is connected to a location corresponding to the suction cell for which measurement is to be performed, and the measurement is carried out. It is also preferable to simultaneously perform particle measurement for a plurality of suction cells. In the example of FIG. 1, an example is shown in which particle measurement is simultaneously performed for two suction cells. By simultaneously performing measurements at a plurality of locations, the inspection time can be shortened. Further, by connecting the soft tube 40 symmetrically with respect to the inspection instrument left and right, the left-right difference in load can be reduced, and unintentional swaying of the inspection instrument and the like can be suppressed.

[0032] FIG. 2 is an explanatory diagram of an inspection instrument 10 which is an example of an inspection instrument according to the present disclosure. The inspection instrument 10 has a probe 11 and a support rod 20. The probe 11 has an arcuate shape as a whole, and a plurality of suction cells 17 are arranged side by side in the circumferential direction. The probe 11 has an outer wall with a U-shaped cross section perpendicular to the circumferential direction and an inner diameter side opening, and a partition wall that partitions the suction cells 17. That is, each of the suction cells 17 is separated by a pair of circumferential walls 13, 13 that face each other and are separated from each other in the circumferential direction, a pair of axial walls 14, 14 that face each other and are separated from 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 the circumferential wall 13.

[0033] The inspection instrument 10 shown in Fig. 2 has 16 suction cells 17. However, the number of suction cells provided in the inspection instrument is not limited to this and can be changed according to the diameter of the probe 11. Each of the suction cells 17 has a tube portion 12 that protrudes outward along the radial direction from the outer diameter side wall 15. The tube portion 12 is, for example, a hard hollow tube with a hole diameter of about 1 to 3 mm. The tube portion 12 is provided in each of the suction cells 17. That is, the probe 11 has a plurality of tube portions 12 (the same number of tube portions 12 as the suction cells 17) that protrude in the radial direction. The tube portion 12 shown in Fig. 2 has a shape that extends linearly, but the tube portion 12 may be linear or may have a bent portion. The plurality of tube portions 12 provided in the probe 11 may all have the same shape or may have different shapes.

[0034] As described above, the probe 11 has an arc shape with a part missing. The central angle of the inspection instrument 10 shown in Fig. 2 is about 320°. However, the arc shape is not limited to this. For example, the probe 11 may be a semi-arc or a 3 / 4 arc. The central angle of the arc of the probe 11 is preferably 180° or more.

[0035] Fig. 3 is a diagram showing an enlarged part of the inspection instrument 10 shown in Fig. 2. As an example of the specific dimensions of the inspection instrument 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 such a form, a suction cell in a form conforming to the suction probe specified in the public standard (for example, ISO14644-3:2019) can be configured.

[0036] When performing a leak inspection of the filter, a flexible tube 40 is attached to a tube portion 12 provided on the probe 11, and a connector 45 may be attached between the tube portion 12 and the flexible tube 40. By using the connector 45 made of a material harder than the flexible tube, it is possible to prevent the flexible tube 40 from being bent. In particular, when measuring the suction cell located above the horizontal level, if a flexible tube is connected to the tube portion and allowed to hang down, there is a risk of the tube being bent. In such a case, it is preferable to use a connector.

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

[0038] FIG. 4 is an explanatory diagram of another embodiment of the inspection instrument 10 according to the present disclosure. While the inspection instrument 10 shown in FIG. 1 is supported by the support rod 20, the inspection instrument 10 in FIG. 4 is supported in a form of being suspended from the ceiling by a hanger 35.

[0039] Referring to FIG. 4, the inspection instrument 10 is disposed so as to surround the outer periphery of the sock filter 200 fixed to the duct 500 in the clean room. 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 the entire axial length of the filter body 210. The filter body 210 and the suspension belt 220 are integrated. Sewing holes 222 are formed in the suspension belt 220 at regular intervals, and suspension hooks 310 are attached to the sewing holes 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, 32 are fixed to the ceiling in parallel with the rail 300 so as to sandwich the rail 300. Note that the rails 300, 31, 32 may be dedicated components fixed to the ceiling of the clean room or may be part of the structural material of the clean room.

[0040] The inspection instrument 10 is suspended and supported via bifurcated suspensions 35 installed on each of a pair of rails 31, 32 fixed to the ceiling. The inspection instrument 10 has a pipe portion 12 that protrudes radially outward. The inspection instrument 10 has a plurality of suction cells 17 (see FIG. 2), and a flexible tube 40 is attached to the pipe portion corresponding to the suction cell that performs measurement. The flexible tube 40 is connected to a measuring device 60 (see FIG. 1). When the inspection instrument 10 is suspended from the ceiling, the inspection instrument 10 can be held more stably, and inspection can be performed while appropriately maintaining the distance between the sock filter 200 and the inspection instrument 10.

[0041] As shown in FIG. 4, a leak inspection is performed by scanning while moving the inspection instrument 10 in the direction of the arrow along the sock filter 200. The number of inspection instruments 10 installed with respect to the sock filter 200 is not particularly limited. The number of inspection instruments 10 installed with respect to the sock filter 200 may be one or two or more.

[0042] In the form shown in FIG. 4, the suspension tool 35 is attached to each of the left and right sides of the probe 11. Further, the suspension tool 35 has a bifurcated shape and is connected at two locations on the front side and the back side in the axial direction of the probe 11. The specific shape of the suspension tool 35 is not limited to this, and it may be a shape that supports each of the left and right sides of the probe 11 with a single member. When the bifurcated suspension tool 35 is adopted, the inspection instrument 10 is held more stably, so that the leak inspection can be surely carried out while appropriately maintaining the clearance between the probe 11 and the filter body 210.

[0043] The embodiments disclosed herein should be construed as illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all modifications within the meaning and scope equivalent to the claims be included.

Explanation of Signs

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

Claims

1. An inspection instrument for a sock filter, comprising an arc-shaped probe in which a plurality of suction cells are arranged side by side in the circumferential direction, wherein a cross-section perpendicular to the circumferential direction of the probe has a U-shape with an open inner diameter side, each of the suction cells is defined by a pair of circumferential walls facing each other and spaced apart from each other in the circumferential direction, a pair of axial walls facing each other and spaced apart from each other in the axial direction, and an outer diameter side wall that closes the outer diameter side in the radial direction, and adjacent suction cells share a circumferential wall.

2. The inspection instrument for a sock filter according to claim 1, wherein the suction cell has a pipe portion protruding outward from the outer diameter side wall.

3. The inspection instrument for a sock filter according to claim 1 or claim 2, wherein the probe has an arc shape with a part missing.

4. An inspection apparatus for a sock filter, comprising a cart, a measuring device installed on the cart, the inspection instrument for a sock filter according to claim 1 or claim 2, and a flexible tube connecting the inspection instrument and the measuring device.

5. The inspection apparatus for a sock filter according to claim 4, wherein the inspection instrument has a support portion connected to the probe, and the support portion is fixed to the cart.

6. The inspection apparatus for a sock filter according to claim 4, wherein the inspection instrument has a support portion connected to the probe, and the support portion is held by a rail installed on the ceiling.

7. A method for inspecting a sock filter using the inspection instrument according to claim 1 or claim 2, comprising: a preparation step of arranging the inspection instrument so that the probe in the inspection instrument surrounds the outer circumference of the sock filter to be inspected; an inspection step of moving the inspection instrument along the axial direction of the sock filter while checking for leaks.

8. The method for inspecting a sock filter according to claim 7, wherein in the inspection step, leak checks are simultaneously performed on two or more of the plurality of suction cells provided in the inspection instrument.

9. A method for inspecting a sock filter using an inspection apparatus for a sock filter, comprising a cart, a measuring device installed on the cart, the inspection instrument for a sock filter according to claim 1 or claim 2, and a flexible tube connecting the inspection instrument and the measuring device, wherein the method comprises: ​ ​ ​ ​ ​ ​ ​ ​ A preparation step of arranging the inspection instrument so that the probe in the inspection instrument surrounds the outer periphery of the sock filter that is the inspection target; An inspection step of performing leak confirmation while moving the inspection instrument along the axial direction of the sock filter, including: In the inspection step, the carriage travels on a rail laid in parallel with the sock filter. A method for inspecting a sock filter.

10. The inspection instrument has a support portion connected to the probe, and the support portion is fixed to the carriage. In the inspection step, the inspection instrument is supported by the carriage and moves integrally with the carriage. The method for inspecting a sock filter according to claim 9.

11. The inspection instrument has a support portion connected to the probe, and the support portion is held by a rail installed on the ceiling. In the inspection step, the inspection instrument moves along the rail installed on the ceiling. The method for inspecting a sock filter according to claim 9.

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