Box shaped high performance air filter

Abstract

To provide a box shaped high performance air filter which can inhibit deformation of a container during earthquake and achieve high pressure resistance to decompression.SOLUTION: A box shaped high performance air filter 1 includes: a filter body 10 which filters air passing therethrough; a hexahedron container 20 which houses the filter body 10 and has an inlet nozzle 32 (1) for introducing air, and an outlet nozzle 32 (2) for discharging air which has been filtered by the filter body 10 and is located on a surface opposite to the inlet nozzle 32 (1); and a reinforcement material 40 fastened to the container 20. The filter body 10 is adhered to an inner surface of the container 20 and the natural frequency is 20 Hz or higher.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a box-type high-performance air filter, and more particularly to a box-type high-performance air filter having excellent earthquake resistance and pressure resistance. [Background technology]

[0002] In high-performance air filters for removing radioactive particles used in the exhaust system from nuclear facilities, especially glove boxes, box-type high-performance air filters are often used to contain radioactive materials during maintenance of the air filter. In a box-type high-performance air filter, the filter body, in which the filter material is folded into pleats and a separator is built in between, is housed in a box-shaped container, air is taken in from an inlet nozzle connected to the container, and the air filtered by the filter body is exhausted through an outlet nozzle. For example, in the case of a box-type high-performance air filter in the exhaust system of a glove box, the box-type high-performance air filter is installed by fastening it to the glove box with a band from the viewpoint of maintenance and effective use of space, and the exhaust air filtered by a sealed replaceable filter unit is exhausted to the atmosphere through a suction fan.

[0003] As shown in Patent Document 1, in a conventional box-shaped high-performance air filter, a filter body (filter element 22, separator 23) is housed in a box-shaped container (can body 1), and the container and the filter body are bonded and fixed with an adhesive (silicone-based adhesive 32).

[0004] Meanwhile, high-performance air filters for radioactive aerosols are specified in the Japanese Industrial Standard JIS-Z4812. This standard specifies that the dimensions of a box-type high-performance air filter should be 203 x 203 x 228 mm-610 x 610 x 508 mm depending on the rated flow rate, and that the outer frame of the high-performance air filter should be made of plywood or metal. For example, it can be made of a metal plate, as in the case of the can in Patent Document 1.

[0005] In recent years, the demand for safety of nuclear power facilities has been increasing, and the demand for earthquake-resistant and pressure-resistant design of box-type high-performance air filters is also increasing. However, the demand for earthquake-resistant design is not taken into consideration in the JIS standard. It is difficult to meet the demand for earthquake resistance with a plywood outer frame, so it is common to use a metal plate outer frame. The JIS standard specifies the thickness of the metal plate as 1.2-2.3 mm, but if the container is damaged or deformed during an earthquake, the filter performance cannot be achieved. If the container is deformed too much, the filter body bonded to the container will be distorted and deformed, and the filter body may be damaged, or the adhesive that fixes the filter body to the container will come off. Therefore, it is required to make the box-type high-performance air filter a rigid body. As a part of this, it is becoming necessary to set the natural frequency to 20 Hz or more.

[0006] Furthermore, the JIS standard requires that the pressure resistance of the filter body must be tested by increasing the flow rate until the filter pressure loss reaches 24.5 hPa and maintaining this pressure for one hour, and that the return pressure after the inside is reduced to -10 hPa must be 5% / min or less of the test pressure. However, as mentioned above, box-type high-performance air filters are often used by sucking in air with a suction fan, and in recent years there has been a demand for them to withstand lower negative pressures. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 10-48391 (see paragraphs 0008-0009 and Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0008] SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide a box-type high-performance air filter capable of suppressing deformation of the container during an earthquake and having high pressure resistance against reduced pressure. [Means for solving the problem]

[0009] In order to solve the above problems, a box-type high-performance air filter 1 according to a first embodiment of the present invention, as shown in FIG. 1 for example, comprises a filter body 10 that filters passing air, and a hexahedral container 20 that houses the filter body 10, the container 20 having an inlet nozzle 32(1) for introducing air and an outlet nozzle 32(2) for discharging air filtered by the filter body 10 on the face opposite the inlet nozzle 32(1), and a reinforcing member 40 fixed to the container 20, the filter body 10 being bonded to the inner face of the container 20, and the natural frequency being 20 Hz or more.

[0010] With this configuration, the filter body is adhered to the inner surface of the container, stabilizing the position of the filter body within the container and preventing air taken into the container from passing through without passing through the filter body. The container is reinforced with reinforcing material and has a natural frequency of 20 Hz or more, thereby preventing deformation of the container during an earthquake and providing a box-shaped high-performance air filter with high pressure resistance.

[0011] 1, the box-shaped high-performance air filter 1 according to the second embodiment of the present invention has a hexahedral container 20 having a cylindrical portion 22 with a rectangular cross section, an inlet cover 30(1) constituting a surface having an inlet nozzle 32(1), and an outlet cover 30(2) constituting a surface having an outlet nozzle 32(2), and connecting portions 24 that protrude outward from the rectangular cross section are formed at both ends of the cylindrical portion 22, and the inlet cover 30(1) and the outlet cover 30(2) have surface-joining portions 34 that are surface-joined with the connecting portions 24, and the connecting portions 24 and the surface-joining portions 34 are connected with a connecting member 80, so that the cylindrical portion 22, the inlet cover 30(1) and the outlet cover 30(2) are integrated to form the container 20. With this configuration, the container is composed of the cylindrical portion, the inlet cover, and the outlet cover, and thus maintenance of the filter body stored in the container is easy.

[0012] In order to solve the above problems, in the box-shaped high-performance air filter 3 according to the third aspect of the present invention, a reinforcing material 46 is fixed to the inner surface of the container 20, as shown in Fig. 3 for example. With this configuration, since the reinforcing material is fixed to the inner surface of the container, the reinforcing material does not get in the way when handling the box-shaped high-performance air filter, and even if the reinforcing material is not fixed to the entire inner surface of the container, it functions as a reinforcing material against negative pressure, and fixing of the reinforcing material does not become complicated.

[0013] 1, the box-shaped high-performance air filter 1 according to the fourth aspect of the present invention is formed with legs 60 extending from the container 20, and the legs 60 are fixed to a stand on which the box-shaped high-performance air filter 1 is placed. With this configuration, the box-shaped high-performance air filter can be securely fixed to the stand, preventing it from moving during an earthquake and suppressing deformation of the box-shaped high-performance air filter.

[0014] 1 and 4, in a box-shaped high-performance air filter 1 according to a fifth embodiment of the present invention, the inlet nozzle 32(1) and the outlet nozzle 32(2) are each connected to piping via a sleeve 100, an L-shaped notch 110 is formed at the end of the sleeve 100 that is inserted into the inlet nozzle 32(1) or the outlet nozzle 32(2), and a stop pin 38 that engages with the notch 110 is provided on the inner surface of the inlet nozzle 32(1) or the outlet nozzle 32(2). With this configuration, the inlet and outlet nozzles are firmly connected to the sleeve, so they will not come off even during an earthquake, resulting in a box-shaped high-performance air filter with excellent earthquake resistance.

[0015] In the box-type high-performance air filter 1 according to the sixth aspect of the present invention, an L-shaped notch is formed in the inlet nozzle 32(1) or the outlet nozzle 32(2), and a locking pin that engages with the notch is provided on the outer surface of the sleeve 100 inserted into the inlet nozzle 32(1) or the outlet nozzle 32(2). With this configuration, the inlet and outlet nozzles are firmly connected to the sleeve, so that the filter will not come off even during an earthquake, resulting in a box-type high-performance air filter with excellent earthquake resistance. Effect of the Invention

[0016] According to the box-type high-performance air filter of the present invention, the container that houses the filter body is reinforced with a reinforcing material, and the natural frequency is set to 20 Hz or more. This makes it possible to suppress deformation of the container during an earthquake, and results in a box-type high-performance air filter that is highly resistant to reduced pressure. [Brief description of the drawings]

[0017] [Figure 1] 1 is a partially sectional side view of a box-shaped high-performance air filter according to one embodiment of the present invention, the filter having a reinforcing material on the outside of the container and a structure in which the filter is fixed to a stand or the like by legs. [Diagram 2] 1A and 1B are side and front cross-sectional views of a box-type high-efficiency air filter having cross-shaped reinforcements on the exterior of the container according to another embodiment of the present invention; FIG. [Diagram 3] FIG. 11 is a cross-sectional side view of a main portion of a box-shaped high-performance air filter having a reinforcing material on the inside of the container, according to still another embodiment of the present invention. [Figure 4] FIG. 2 is a perspective view illustrating the details of a connecting portion between a nozzle and a sleeve of the box-type high-performance air filter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each drawing, the same or corresponding parts are given the same reference numerals, and duplicated explanations will be omitted. First, a box-type high-performance air filter 1 as one embodiment of the present invention will be described with reference to the partial cross-sectional side view of FIG.

[0019] The box-shaped high-performance air filter 1 includes a filter body 10 in which a filter material 12 is folded into pleats and a separator 14 is assembled between the pleats. The filter 10 is typically a high-performance filter such as a HEPA filter or a ULPA filter. The filter body 10 is disposed in a hexahedral container 20. The container 20 includes a cylindrical portion 22 formed into a cylindrical shape with a rectangular cross section by four faces of the hexahedron, and an inlet cover 30(1) and an outlet cover 30(2) that are installed to cover the opening of the cylindrical portion 22. The inlet cover 30(1) is provided with an inlet nozzle 32(1) that takes in air to be filtered by the box-shaped high-performance air filter 1, and the outlet cover 30(2) is provided with an outlet nozzle 32(2) that exhausts the air filtered by the box-shaped high-performance air filter 1. The inlet cover 30(1) and the outlet cover 30(2) are collectively referred to as the cover 30, and the inlet nozzle 32(1) and the outlet nozzle 32(2) are collectively referred to as the nozzle 32.

[0020] The outer periphery of the surface of the filter body 10 perpendicular to the air flow is adhered and fixed to the inside of the cylindrical portion 22 of the container 20 with adhesive 16. By being adhered and fixed, the position of the filter body 10 is stabilized within the container 20, and air taken into the container 20 can be prevented from passing through without passing through the filter body 10.

[0021] A connecting portion 24 is formed on the end surface of the cylindrical portion 22, which protrudes outward from the rectangular cross section. The outermost edge of the connecting portion 24 may have a seam fold 26 bent in a direction along the cylindrical portion 22. The cover 30 may also have a size that protrudes outward from the cylindrical portion 22, that is, a surface joint portion 34 where the flat plate on which the nozzle 32 is erected is surface-joined with the connecting portion 24. The outermost edge of the surface joint portion 34 may have a seam fold 36 so as to cover the seam fold 26 of the connecting portion 24. The cylindrical portion 22 and the cover 30 can be integrated with a connecting member 80 such as a bolt and a nut that penetrates the connecting portion 24 and the surface joint portion 34. This configuration makes it possible to easily remove the cover 30, and to easily maintain the stored filter body 10, resulting in a box-shaped high-performance air filter 1. In addition, a seam fold is formed on the connecting portion 24 and the surface joint portion 34, and the bolt is tightened with a nut on the inside of the seam fold, thereby preventing the nut from hitting something and loosening. It should be noted that the hexahedron referred to as the hexahedron container 20 does not necessarily mean a hexahedron in the strict sense, and the container 20 may be provided with connection portions 24, 34 and seam folds 26, 36, and the like.

[0022] A gasket 70 may be provided between the connection portion 24 and the surface joint portion 34 to improve the sealing performance. When the box-shaped high-performance air filter 1 is used to remove radioactive particles in an exhaust system from a glove box or the like of a nuclear facility, it is required to prevent the radioactive particles from leaking out of the system, and therefore improving the sealing performance is effective.

[0023] A reinforcing material 40 is fixed to the outside of the cylindrical portion 22 of the container 20. The reinforcing material 40 can be appropriately selected from plate material, bar material, steel section, etc. In the box-shaped high-performance air filter 1, the reinforcing material 40 is arranged along the outer periphery of the cylindrical portion 22. The number of reinforcing materials 40 to be installed may be appropriately selected depending on the size of the box-shaped high-performance air filter 1, the weight of the main filter 10, the thickness of the container 20, etc. It is preferable that the height of the reinforcing material 40 does not exceed the protruding height of the surface joint portion 34 of the cover 30. Such a configuration is preferable because the reinforcing material 40 does not get in the way when the box-shaped high-performance air filter 1 is installed on a stand or the like.

[0024] 2, a reinforcing member 42 arranged along the outer periphery of the cylindrical portion 22 and a reinforcing member 44 arranged in the axial direction may be fixed to the cylindrical portion 22. By arranging the reinforcing members 42, 44 in a lattice pattern in this manner, the effect of reinforcing the container 20 can be further increased.

[0025] Also, a reinforcing plate 52 may be fixed to the periphery of the nozzle 32 of the cover 30. The reinforcing plate 52 reinforces the cover 30, and in particular makes it possible to prevent distortion of the cover 30 due to shaking of the nozzle 32.

[0026] Also, as in the box-shaped high-performance air filter 3 shown in FIG. 3, a reinforcing material 46 may be fixed to the inside of the container 20. By fixing the reinforcing material 46 to the inside of the container 20, the reinforcing material protruding from the outside of the container 20 can be eliminated, and the reinforcing material does not get in the way when the box-shaped high-performance air filter 3 is transported, installed, or fixed, and is also preferable in terms of appearance. Also, a rectangular tubular or cylindrical reinforcing material 48 may be fixed perpendicularly to the inner surface of the cover 30(2). The reinforcing material 48 may be a polygonal column instead of a rectangular tubular shape in which the inner surface of the cylindrical portion 22 is reduced or a cylindrical shape in which the outer diameter of the nozzle 32(2) is enlarged. When the reinforcing materials 46, 48 are fixed to the inner surface of the container 20, even if they are not fixed all over the surface, for example, even if they are fixed at several points in a spot manner, the container 20 tries to deform inward in response to negative pressure, so that the reinforcing material functions sufficiently as a reinforcing material against negative pressure. Therefore, even if the reinforcing members 46, 48 are disposed inside the container 20, unlike reinforcing members for internal pressure, the attachment of the reinforcing members 46, 48 does not become complicated. In addition, by attaching the reinforcing members 48 to the periphery spaced apart from the hole of the nozzle 32(2), it is possible to prevent the reinforcing members 46, 48 from interfering with the flow of air inside the container 20.

[0027] 3, the cover 30(2) may be provided with a reinforcing plate 52 fixed to the outer peripheral surface of the nozzle 32(2), or a reinforcing plate 54 fixed to the periphery of the inner peripheral surface of the base of the nozzle 32(2). Either one of the reinforcing plates 52, 54 may be fixed, or both may be fixed. The cover 30(2) of the box-type high-performance air filters 1, 2 may also be reinforced with the reinforcing plates 52, 54.

[0028] As shown in Figs. 1 and 3, the box-shaped high-performance air filters 1, 2, and 3 may have legs 60 extending from the container 20. Conventional box-shaped high-performance air filters were generally fastened to a stand such as a glove box with a band. In this document, the term "stand" includes not only structures for installing box-shaped high-performance air filters, but also structures for other purposes on which the box-shaped high-performance air filters can be installed. However, if the air filters are simply fastened with bands, there is a possibility that the box-shaped high-performance air filters will move during an earthquake, causing distortion and deformation. Therefore, by forming the legs 60 and fixing the legs to the stand, the box-shaped high-performance air filters 1, 2, and 3 can be prevented from moving during an earthquake, and earthquake resistance can be further improved. It is desirable that the legs 60 are not simply plate members 62, but are provided with ribs 64 to make them strong and suppress shaking during an earthquake.

[0029] FIG. 4 is a perspective view illustrating a connecting portion between the nozzle 32 and the sleeve 100 of the box-shaped high-performance air filters 1, 2, and 3. In the box-shaped high-performance air filters 1, 2, and 3, the inlet nozzle 32(1) and the outlet nozzle 32(2) are connected to piping, and an air flow path is formed from the air supply source to the destination or exhaust destination. For this purpose, the nozzle 32 is connected to the piping (not shown) via the sleeve 100, which is a sliding sleeve. Since the sleeve 100 is slidable, there is a risk that it may slide off during an earthquake. For this reason, an L-shaped notch 110 is formed at the end of the sleeve 100 that is inserted into the nozzle 32. Then, a stop pin 38 is provided on the inner surface of the nozzle 32. When the sleeve 100 is inserted into the nozzle 32, the stop pin 38 is inserted into the notch 110, and the sleeve 100 is further twisted so that the stop pin 38 fits into the L-shaped recess of the notch 110. This makes it possible to prevent the sleeve 100 from coming off the box-shaped high performance air filters 1, 2, and 3 from the nozzle 32 even during an earthquake, improving earthquake resistance.

[0030] Although not shown, an L-shaped notch may be formed at the tip of the nozzle 32, and a locking pin that engages with the notch may be provided on the outer surface of the sleeve 100 that is inserted into the nozzle 32. EXAMPLES

[0031] As an example, a vibration test performed using an actual machine will be described. The box-shaped high-performance air filter used in the vibration test has a container with a length of 508 mm, a width of 610 mm, and a height of 610 mm, and has an inlet nozzle and an outlet nozzle with an outer diameter of 355.6 mm and a length of 100 mm. The plate thickness of the upper part of the tube was 1.5 mm, the plate thickness of the inlet cover and the outlet cover was 3 mm, and the plate thickness of the nozzle was 8 mm. A rectangular cylindrical reinforcing material of 548 mm x 548 mm was fixed to the inner surface of the inlet cover and the outlet cover. The reinforcing material had an inner height of 25 mm and a thickness of 6 mm. The reinforcing material was welded all around the inlet cover and the outlet cover. In addition, the material of both was JIS SUS304 material. The filter body was a HEPA filter with dimensions of 572 x 572 x 150 mm and a weight of about 9.3 kg. The box-shaped high-performance air filter was installed by fixing the legs to the test machine.

[0032] The test was performed under the following conditions using a resonance search tester. Frequency: 5-100Hz Acceleration: 0.1G Sweep method: logarithmic sweep Sweep speed: 1min / octave Number of sweeps: 1 each way Vibration direction: Length, width, and height Vibration measurement points: Two points on the top of the cover

[0033] The results of the resonance search test showed that the box-type high-performance air filter had no resonance frequencies below 20 Hz. [Explanation of symbols]

[0034] 1, 2, 3 Box-type high-performance air filter 10 Filter body 20 containers 22 Cylindrical part 24 Connection part 26. Hazel Fold 30(1) Entrance cover 30(2) Exit cover 32(1) Inlet nozzle 32(2) Outlet nozzle 34 Surface joint part 36. Seaweed Fold 38 Stop pin 40, 42, 44, 46, 48 Reinforcement 52, 54 Reinforcement plate 60 Legs 62 Plate members 64 Ribs 70 Gasket 80 Connection parts 100 sleeve 110 L-shaped cutout

Claims

1. A filter body for filtering air passing therethrough; a hexahedral container for housing the filter body, the container having an inlet nozzle for introducing air and an outlet nozzle for discharging air filtered by the filter body on a surface opposite to the inlet nozzle; a reinforcement member secured to the container; the filter body is adhered to an inner surface of the container; The natural frequency is 20 Hz or more; Box-type high-performance air filter.

2. The hexahedral container has a cylindrical portion with a rectangular cross section, an inlet cover constituting a surface having the inlet nozzle, and an outlet cover constituting a surface having the outlet nozzle, a connecting portion that projects outward from the rectangular cross section at each end of the cylindrical portion, the inlet cover and the outlet cover have a surface-joint portion that is surface-joined with the connecting portion, and the connecting portion and the surface-joint portion are connected with a connecting member, so that the cylindrical portion, the inlet cover, and the outlet cover are integrated to form the container.

2. The box-type high performance air filter of claim 1.

3. the reinforcement material is affixed to an inner surface of the container; 3. The box-type high performance air filter of claim 2.

4. A leg extending from the container is formed, The legs are fixed to a stand on which the box-shaped high-performance air filter is placed.

4. A box-type high-performance air filter according to claim 1.

5. the inlet nozzle and the outlet nozzle are each connected to a pipe via a sleeve; An L-shaped notch is formed at an end of the sleeve that is inserted into the inlet nozzle or the outlet nozzle, A locking pin that engages with the notch is provided on the inner surface of the inlet nozzle or the outlet nozzle.

4. A box-type high-performance air filter according to claim 1.

6. the inlet nozzle and the outlet nozzle are each connected to a pipe via a sleeve; An L-shaped notch is formed in the inlet nozzle or the outlet nozzle, A locking pin that engages with the notch is provided on the outer surface of the sleeve that is inserted into the inlet nozzle or the outlet nozzle.

4. A box-type high-performance air filter according to claim 1.

Images