JP5443230B2 - Fan filter unit - Google Patents

Description

  The present invention relates to a fan filter unit equipped with an ion generator, and more particularly to a fan filter unit used in a clean room such as a food factory or a hospital.

  In a clean room such as a food factory or a hospital, clean air that has passed through a HEPA filter is generally supplied indoors in order to avoid exposure of foreign substances, bacteria, viruses, and the like to food and patients. Bacteria and viruses often adhere to dust and float, and thus the HEPA filter can remove bacteria and the like together with dust. However, the air that has just passed through the HEPA filter does not have a sterilizing function, and the bacteria once brought to the downstream side of the filter remain in the room as they are.

  Thus, as described in Patent Document 1, an air cleaner in which an air filter for removing dust and an ion generator for decomposing and removing bacteria and the like has been developed. The ion generator generates ions by applying a voltage higher than the discharge voltage between the discharge electrodes, and decomposes and removes bacteria and the like by the ions. The ion generator is usually arranged on the downstream side of the air filter in order to prevent the generated ions from being lost by the HEPA filter.

Japanese Patent No. 3680121

  By the way, in the above-mentioned air purifier, it is necessary to pass air having a relatively high wind speed through the ion generator in order to sweep ions generated locally between the discharge electrodes into the room. Therefore, for example, it is necessary to increase the air speed itself of the air passing through the filter, or to squeeze the air from the filter once before passing through the ion generator.

  However, the air that has passed through the ion generator at a high wind speed is directed to a local portion in the room, and without an ion diffusing device or the like, it is difficult to diffuse the ions throughout the room. In addition, if a fan or the like is provided downstream of the air filter in order to diffuse ions, the fan may become a dust generation source.

  The present invention has been made in view of the above problems, and provides a fan filter unit capable of diffusing clean air containing ions over a wide range in a room without complicating the structure of the apparatus. For the purpose.

  A fan filter unit according to the present invention includes a blower, a casing, a low-pressure loss filter and a high-pressure loss filter that are arranged inside the casing, allow air sent from the blower to pass through, and send air to the downstream side of each. An ion generator disposed downstream of the loss filter. In the present invention, the low-pressure loss filter and the air outlet of the high-pressure loss filter are disposed so as to be close to each other, and the low-pressure loss filter tends to have the same pressure loss as the high-pressure loss filter, so that it passes through the low-pressure loss filter. The passing wind speed is faster than the high pressure loss filter. In the present specification, the low-pressure loss filter and the high-pressure loss filter mean filters having a low pressure loss at the same wind speed, respectively.

  The total opening area of the air delivery port of the low pressure loss filter is preferably smaller than the total opening area of the air delivery port of the high pressure loss filter, and the air delivery port of the low pressure loss filter and the high pressure loss filter are arranged on the same plane. It is better to be. The ion generator preferably generates at least negative ions.

  It is better to provide at least two of the low-pressure loss filter and the high-pressure loss filter. In this case, the other filter is arranged, for example, between two one filters. Two or more one filters may be arranged so as to surround the other filter. The other filter is disposed so as to face the blower, for example.

  In the present invention, by incorporating two or more filters having different pressure losses into the fan filter unit, the purified air purified by the filter and containing ions can be easily diffused indoors.

It is a perspective view which shows the fan filter unit of 1st Embodiment. It is arrow sectional drawing which follows the II-II line. It is the top view which looked at the fan filter unit of a 1st embodiment from the lower part. It is a graph which shows the performance of a low pressure loss filter and a high pressure loss filter. It is the top view which looked at the fan filter unit of 2nd Embodiment from the downward direction.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 3 show a fan filter unit according to a first embodiment of the present invention. The first embodiment of the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the fan filter unit 10 includes a casing 11, a blower 12, a high-pressure loss filter 13, low-pressure loss filters 14 </ b> A to 14 </ b> D, and ion generators 15 </ b> A to 15 </ b> D disposed inside the casing 11. The fan filter unit 10 is for, for example, sending out clean air containing negative ions into a room such as a clean room, and is usually installed on a ceiling surface of the clean room or the like.

  The casing 11 has a rectangular box shape with an opening at the bottom, and includes a rectangular bottom surface 11A and a side surfaces 11B to 11E. A rectangular partition plate 16 is provided inside the casing 11. As for the partition plate 16, each outer edge part which comprises each edge | side of the square is connected with the internal peripheral surface of each of the side surfaces 11B-11E. That is, the entire periphery of the partition plate 16 is connected to the inner peripheral surface of the casing 11 to form a space 19 between the partition plate 16 and the bottom surface 11A.

  The blower 12 includes a main body portion 21, a rotating portion 22 provided so as to surround the main body portion 21, and a connecting portion 23 that connects the main body portion 21 and the rotating portion 22. The main body 21 is attached to the bottom surface 11A of the casing, and includes a motor (not shown) therein. The rotating unit 22 has a plurality of curved plate-like blades 25 arranged radially.

  The bottom surface 11 </ b> A of the casing 11 is provided with an air outlet 11 </ b> F at a position facing the blower 12. The blower 12 rotates the rotating portion 22 (that is, the blade 25) by the driving force of the motor, takes air into the space 19 from the air outlet 11F, and diffuses the air radially. Thereby, the inside of the space 19 is maintained at a constant static pressure of about 130 to 140 Pa.

  The high pressure loss filter 13 and the low pressure loss filters 14 </ b> A to 14 </ b> D are disposed below the blower 12, that is, downstream of the blower 12. The filters 13 and 14A to 14D are attached to the upper surface of the partition plate 16, and are disposed on the same plane.

  The high-pressure loss filter 13 is a round filter and includes an annular filter frame 31 and a filter medium 32 accommodated in the filter frame 31. Similarly, each of the low-pressure loss filters 14 </ b> A to 14 </ b> D is a round filter, and includes an annular filter frame 41 and a filter medium 42 housed inside the filter frame 41. Each of the filter media 32 and 42 is formed by folding a sheet-like filter media into a pleated shape, and has a disk shape, and its outer peripheral surface is bonded to the inner peripheral surfaces of the filter frames 31 and 41.

  In the present embodiment, a glass filter medium is used as the filter medium 32 of the high-pressure loss filter 13 and a PTFE filter medium is used as the filter medium 42 of the low-pressure loss filters 14A to 14D. The sheet thickness of the PTFE filter medium is thinner than that of the glass filter medium, and the pressure loss under the same wind speed of the low pressure loss filters 14 </ b> A to 14 </ b> D is made smaller than that of the high pressure loss filter 13. The filters 13 and 14A to 14D are HEPA filters, but may be filters other than the HEPA filter such as a medium performance filter as long as it is a particulate removal filter.

  Each filter 13 and 14A-14D is arrange | positioned so that one opening part 31A and 41A of the filter frames 31 and 41 may face upward, and the other opening part 31B and 41B may face downward. Therefore, the air sent from the blower 12 is taken into the filter from the one opening 31A, 41A, passes through the filter medium 32, 42, and is sent out downward from the other opening 31B, 41B. At this time, fine dust particles in the air are removed by the filter media 32 and 42.

  The high-pressure loss filter 13 is attached to the center of the partition plate 16 and faces the blower 12 in the center of the casing 11. The low pressure loss filters 14 </ b> A to 14 </ b> D are respectively arranged at the four corners of the casing 11 and surround the high pressure loss filter 13. The filters 14 </ b> A to 14 </ b> D are arranged rotationally symmetrically about the center position of the high-pressure loss filter 13. The low pressure loss filters 14 </ b> A to 14 </ b> D are adjacent to the high pressure loss filter 13.

  The high-pressure loss filter 13 has such a size that the area of the opening 31B (opening area) occupies a majority of the opening area of the casing 11, while the low-pressure loss filters 14A to 14D are provided at each corner of the casing 11. The size is enough to fit in the part. As a result, the total area (opening area) of the openings 41B of the low-pressure loss filters 14A to 14D is smaller than the opening area of the opening 31B of the high-pressure loss filter 13.

  As shown in FIG. 3, the partition plate 16 is provided with a large hole 17 and small holes 18A to 18D at positions corresponding to the high pressure loss filter 13 and the low pressure loss filters 14A to 14D, respectively. Each of the large hole 17 and the small holes 18A to 18D is a round hole whose diameter is slightly larger than the diameter of each of the openings 31B and 41B of the filters 13 and 14A to 14D. Thereby, the large hole 17 and the small holes 18A to 18D have the same shape as the filters 13 and 14A to 14D, and are arranged at the same positions. That is, the small holes 18 </ b> A to 18 </ b> D are arranged so as to surround the large hole 17 and to be adjacent to the large hole 17. Further, the total opening area of the small holes 18 </ b> A to 18 </ b> D is smaller than the opening area of the large hole 17.

  Each of the filters 13 and 14A to 14D is disposed so as to close the holes 17 and 18A to 18D from above, and the openings 31B and 41B of the filters 13 and 14A to 14D are formed in the holes 17, 18A to 18D, respectively. opposite. Therefore, the air sent out from the openings 31B and 41B of the filter is further sent out to the downstream side of the fan filter unit 10 through the holes 17 and 18A to 18D. In other words, in the present embodiment, the large holes 17 and the small holes 18A to 18D that are arranged adjacent to each other and arranged in the same plane constitute the air delivery port of the high pressure loss filter 13 and the low pressure loss filters 14A to 14D. To do. As will be described later, the air sent out from these air delivery ports is mixed on the downstream side.

  A gasket (not shown) is attached to the lower surface of each filter frame 31, 41. The filters 13 and 14A to 14D are attached to the partition plate 16 via gaskets, thereby preventing air that does not pass through the filter media 32 and 42 from leaking from the gaps between the filters 13, 14A to 14D and the partition plate 16. The

  Each of the ion generators 15 </ b> A to 15 </ b> D is disposed at a position corresponding to each of the low-pressure loss filters 14 </ b> A to 14 </ b> D and attached to the lower surface of the partition plate 16. That is, each ion generator 15A-15D is arrange | positioned under each small hole 18A-18D which is a downstream of filter 14A-14D.

  Each of the ion generators 15A to 15D includes a pair of opposing bases 51A and 51B and a pair of holding portions 52A and 52B that connect and hold the bases 51A and 51B. One or more pairs of discharge electrodes (not shown) are provided on the surfaces of the bases 51A and 51B facing each other. When a DC voltage equal to or higher than the discharge voltage is applied between the discharge electrodes, corona discharge occurs, and negative charges are generated near the discharge electrodes. Negative charges act on oxygen and water molecules in the air, generating negative ions. That is, a large amount of negative ions is generated between the bases 51A and 51B.

  As shown in FIG. 3, the pair of bases 51 </ b> A and 51 </ b> B are arranged so as to sandwich the opening 41 </ b> B or the small holes 18 </ b> A to 18 </ b> D of the low-pressure loss filters 14 </ b> A to 14 </ b> D when viewed from below. Therefore, the air from the opening 41B of the low-pressure loss filters 14A to 14D is sent downstream through the pair of bases 51A and 51B. As a result, negative ions between the bases 51A and 51B are pushed downstream by the air from the low pressure loss filters 14A to 14D.

  Here, the low-loss filters 14A to 14D have a relatively small pressure loss at a predetermined wind speed and the same pressure loss as that of the high-pressure loss filter 13, so that the wind speed of air sent vertically downward is relatively fast. The wind speed is preferably 1.2 m / second or more so that negative ions can be sufficiently washed away. In this way, the air having a high wind speed efficiently pushes the negative ions between the bases 51A and 51B to the downstream side, but is sent out downward relatively linearly, that is, without spreading in the horizontal direction (horizontal direction).

  On the other hand, the high pressure loss filter 13 has a relatively large pressure loss at a predetermined wind speed, and sends air having a relatively slow wind speed vertically downward. The wind speed is, for example, 0.5 m / second or less. Thus, air with a low wind speed is sent out vertically downward while spreading in the horizontal direction (horizontal direction).

  In the present embodiment, the air delivery port (that is, the large hole 17) of the high-pressure loss filter 13 is close to the air delivery port (that is, the small holes 18A to 18D) of each of the low-pressure loss filters 14A to 14D. Yes. Therefore, the air from the high-pressure loss filter 13 spread in the lateral direction travels downward while being mixed with the air from the low-pressure loss filters 14A to 14D that have passed through the ion generators 15A to 15D. Thereby, the air sent out from the low pressure loss filters 14A to 14D, that is, negative ions, along with the air from the high pressure loss filter 13, proceeds in the downward direction while diffusing in the lateral direction, and the negative ions are distributed throughout the room. .

  In addition, it is possible to easily diffuse ions with a single blower without providing a separate blower for diffusing ions. Therefore, the object can be achieved with a simple configuration, and dust generation caused by the blower is possible. Is not generated indoors.

  Furthermore, in this embodiment, since the winds from the filters 13, 14A to 14D are mixed and flowed indoors, the wind speed is weakened as a whole, and the patient or the like is not exposed to the wind of high wind speed. In particular, in this embodiment, the total opening area of the high-pressure loss filter 13 (large hole 17) is larger than the total opening area of the low-pressure loss filters 14A to 14D (small holes 18A to 18D). As for the wind, the wind from the high-pressure loss filter 13 is dominant. Therefore, the wind from the unit 10 has a sufficiently low wind speed and can sufficiently diffuse negative ions.

  FIG. 4 is a graph showing the performance of the low pressure loss filter and the high pressure loss filter used in this embodiment. The graph of FIG. 4 is a graph showing the pressure loss (initial pressure loss) of the unused filter with respect to the wind speed. As is clear from FIG. 4, the low pressure loss filter has an increase rate of the initial pressure loss with respect to the increase in the wind speed smaller than the high pressure loss filter, and the pressure loss at the same wind speed is smaller than that of the high pressure loss filter. Can understand. For example, when the static pressure is about 130 to 140 Pa, the high pressure loss filter sends out air at a wind speed of 0.45 m / sec, and the low pressure loss filter sends out air at a wind speed of about 1.2 m / sec.

  FIG. 5 shows a second embodiment of the present invention. In the second embodiment, the number and shape of low-pressure loss filters and high-pressure loss filters, their arrangement, and the like are different from those in the first embodiment. Hereinafter, the difference between the second embodiment and the first embodiment will be described.

  The fan filter unit 10 according to this embodiment includes two high-pressure loss filters 63A and 63B having a relatively large opening area and one low-pressure loss filter 64 having a relatively small opening area. The high-pressure loss filters 63 </ b> A and 63 </ b> B are rectangular filters, and include a rectangular rectangular frame filter frame 71 and a thin rectangular column filter medium 72 inside the filter frame 71. Similarly, the low-pressure loss filter 64 is a rectangular filter, and includes a rectangular quadrangular filter frame 81 and a thin rectangular column filter medium 82 housed inside the filter frame 81. The longitudinal direction of these rectangular filters 63A, 63B, 64 is perpendicular to the side surfaces 11C, 11E facing each other.

  The low-pressure loss filter 64 is disposed at the center of the partition plate 16, that is, the casing 11, and is disposed to face the blower 12. The high pressure loss filters 63 </ b> A and 63 </ b> B are symmetrically arranged on the left and right with the low pressure loss filter 64 as the center. The high pressure loss filters 63A and 63B occupy most of the left half and the right half of the casing 11 when viewed from the lower side, and the low pressure loss filter 64 is interposed therebetween.

  The large holes 87A and 87B and the small holes 88 of the partition plate 16 are formed corresponding to the filters 63A, 63B, and 64, respectively, as in the first embodiment. Accordingly, the holes 87A, 87B, and 88 each have a rectangular shape, and the small hole 88 is disposed so as to be sandwiched between the large holes 87A and 87B.

  Also in this embodiment, the total opening area of the high pressure loss filters 63A and 63B (large holes 87A and 87B) is larger than the opening area of the low pressure loss filter 64 (small hole 88). Further, only one ion generator 65 is provided corresponding to the low pressure loss filter 64 and is arranged at a position corresponding to the low pressure loss filter 64 (small hole 88).

  Similar to the first embodiment, the low-pressure loss filter 64 sends out air having a relatively high wind speed, and the ions generated in the ion generator 65 are pushed downstream by the air. On the other hand, the high-pressure loss filters 63A and 64B send out air having a relatively low wind speed, and ions are diffused throughout the room by the air. Therefore, also in the present embodiment, the purified air that is purified by the filter and contains the ions spreads throughout the room.

  In each of the above embodiments, the low-pressure loss filter and the high-pressure loss filter are attached to the upper surface of the partition plate 16, but may be attached to the lower surface of the partition plate 16. In this case, the lower opening of each filter constitutes an air delivery port for delivering air from the filter to the downstream side.

  Further, in each of the above embodiments, the pressure loss of the low-pressure loss filter at the same wind speed is made smaller than that of the high-pressure loss filter by changing the material of the filter medium, but the pressure loss of these filters may be made different by another method. . For example, by increasing the height of the pleats of the filter medium of the low pressure loss filter or increasing the number of pleats per unit width, the effective area of the filter medium per unit opening area of the low pressure loss filter The pressure loss of the low pressure loss filter at the same wind speed may be made smaller than that of the high pressure loss filter.

  Further, in each of the above embodiments, as described in, for example, Japanese Patent No. 3680121, the ion generator may generate negative ions and positive ions by applying an AC voltage between the discharge electrodes. good.

  In the first embodiment, four low-pressure loss filters are provided, but any number of low-pressure loss filters may be used as long as the number is one or more. For example, the filters 14B and 14D may be omitted, and only two low-pressure loss filters 14A and 14C arranged so as to sandwich the high-pressure loss filter 13 therebetween may be provided. A plurality of high-pressure loss filters may be provided.

  Similarly, in the second embodiment, two high-pressure loss filters are provided, but any number of high-pressure loss filters may be used as long as it is one or more. For example, four high-pressure loss filters arranged so as to surround the low-pressure loss filter may be provided. A plurality of low-pressure loss filters may be provided. Of course, in the first and second embodiments, the shape of the high-pressure loss filter or the low-pressure loss filter is not limited to a round shape or a rectangular shape, and may be any shape.

DESCRIPTION OF SYMBOLS 10 Fan filter unit 11 Casing 12 Blower 13, 63A, 63B High pressure loss filter 14A-14D, 64 Low pressure loss filter
15A-15D, 65 ion generator

Claims (6)

A blower, a casing, a low-pressure loss filter and a high-pressure loss filter that are arranged inside the casing, allow the air sent from the blower to pass therethrough, and send the air to the downstream side of each, and downstream of the low-pressure loss filter An ion generator arranged,
Air delivery port of the low pressure loss filter and the high-pressure loss filter, while being arranged adjacent to each other, passing through the wind speed passing through the low pressure loss filter, Ri a faster than the high pressure loss filter,
At least two of the low pressure loss filter and the high pressure loss filter are provided, and the other filter is disposed between the one filter. A blower, a casing, a low-pressure loss filter and a high-pressure loss filter that are arranged inside the casing, allow air sent from the blower to pass through, and send air to the downstream side of each, and downstream of the low-pressure loss filter An ion generator arranged,
The air outlet of the low pressure loss filter and the high pressure loss filter are arranged so as to be close to each other, and the passing wind speed through the low pressure loss filter is faster than the high pressure loss filter,
A fan filter unit, wherein a plurality of one of the low-pressure loss filter and the high-pressure loss filter are provided, and the plurality of filters are arranged so as to surround the other filter. 3. The fan filter unit according to claim 1, wherein a total opening area of the air delivery port of the low-pressure loss filter is smaller than a total opening area of the air delivery port of the high-pressure loss filter. 3. The fan filter unit according to claim 1, wherein the low-pressure loss filter and the air supply port of the high-pressure loss filter are arranged on the same plane. The fan filter unit according to claim 1 or 2 , wherein the other filter is disposed so as to face the blower. The ion generator, fan filter unit according to claim 1 or 2, characterized in that for generating at least negative ions.

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