WO2001007843A1

WO2001007843A1 - Clean room device

Info

Publication number: WO2001007843A1
Application number: PCT/JP1999/003983
Authority: WO
Inventors: Tsutomu Sasaki; Shuichi Kaijo; Shigeo Yokota; Matsuo Kamitani; Takeshi Honma
Original assignee: Hitachi Plant Engineering & Construction Co., Ltd.
Priority date: 1999-07-26
Filing date: 1999-07-26
Publication date: 2001-02-01
Also published as: KR100620128B1; KR20020019571A

Abstract

A clean room device (15), comprising a ceiling (12) in a room (10) on which fan filter units (14) are disposed at intervals and also vent bodies (40) are installed in vacant lattice spaces where the fan filter units (14) are not installed, wherein, when clean air is fed from a ceiling upper space (16) into the room (10) through the fan filter units (14), a barometric pressure in the room (10) is increased over that in the ceiling upper space (16), and a part of the air in the room (10) flows to the ceiling upper space (16) through the vent bodies (40), whereby a vortex air flow can be prevented from occurring in the lower area of the vacant lattice spaces in the room (10) so as to increase the cleanliness of the interior of the chamber (10).

Description

Clean room equipment

Technical field

The present invention relates to a clean room device, and more particularly to a clean room device requiring high cleanliness, such as a semiconductor manufacturing plant. Light

Background art

Rice field

Ceiling frames are arranged in a lattice on the ceiling of a room of a clean room device such as a semiconductor manufacturing plant, and a fan fill unit is installed in each of the lattice spaces formed by the ceiling frames. The fan filter unit drives the fan to send air in the space above the ceiling of the room (hereinafter referred to as the space above the ceiling) into the room with the power to remove dust by the filter. The sent clean air flows downward and flows together with the dust in the room through the grating floor on the lower surface of the room into the space below the floor (hereinafter referred to as the underfloor space), part of which is in the circulation path. The air is guided to the space above the ceiling via the, and the remaining air is exhausted outside the clean room equipment. The air led into the space above the ceiling is sent into the room while being dust-removed again by the fan filter unit. This keeps the room air clean.

The fan filter units are not necessarily installed in all grid spaces, but may be arranged at regular intervals to reduce equipment costs / running costs. In this case, each of the grid spaces where the fan filter unit is not installed (hereinafter referred to as “vacant grid space”) is installed on the ceiling to prevent the air before cleaning the space above the ceiling from flowing into the room. A blocking plate that completely shuts off the space from the room has been conventionally installed.

However, when the fan filter units are arranged at intervals and the obstruction plates are installed in the empty lattice space as in the past, the indoor cleanliness is greater than when the fan filter units are installed in all the lattice spaces. There was a drawback that the degree could not be increased. Disclosure of the invention

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a clean room apparatus capable of increasing the cleanliness of a room even if the arrangement intervals of fan filter units are increased.

Conventionally, in general, the cleanliness of the clean room equipment in the room depends on the amount of clean air sent into the room.In other words, it is necessary to increase the amount of clean air to improve the cleanliness of the room. , Was considered. Therefore, it was thought that the reason why it was not possible to increase the cleanliness of the room when the interval between the fan-fill units was increased was to reduce the amount of clean air.

However, pursuing the cause of the decrease in indoor cleanliness when the fan filter units are arranged at intervals is not due to the decrease in the volume of clean air, but is due to the empty grid space where the fan filter units are not installed. It was clarified that a swirling air flow was generated in the area below the obstruction plate installed in the room, and that dust was trapped in the room in that area.

The present invention focuses on this point, and achieves an improvement in the cleanliness of a room in which fan filter units are arranged at intervals by suppressing the generation of swirling airflow in the room.

In order to achieve the above object, a clean room apparatus of the present invention includes a room having a ceiling, a fan filter unit installed on the ceiling, for sending clean air from a space above the ceiling into the room, and a fan room mounted on the ceiling. And a part of the air in the room, the difference between the air pressure in the room and the air pressure in the space above the ceiling, Characterized by flowing.

According to the present invention, a ventilation body is installed in an empty lattice space where a fan filter unit is not installed on the ceiling of a room, and the difference between the air pressure in the room and the air pressure in the space above the ceiling causes the air in the room to be removed. A part of the gas flows into the space above the ceiling via gas. As a result, the generation of a swirling airflow in the area below the empty grid space can be prevented, and the cleanliness of the room can be increased. A filter for collecting dust may be used as the ventilation body. This allows the air to pass through Dust in the air is collected by the filter, reducing the load on the filter in the fan-fill unit and preventing dust from the ceiling space from entering the room.

Further, a fan may be installed above the ventilation body having the filter. By operating the fan and sending air from the space above the ceiling to the room through the filter of the ventilator, the filter of the ventilator can perform the function of the fan filter of the fan unit. Therefore, it is particularly advantageous when high cleanliness is required in a region below the empty lattice space. In addition, by inverting the fan and sucking a part of the air in the room through the gas filter into the space above the ceiling, the amount of air flowing from the room to the space above the ceiling can be easily adjusted. Also, when the indoor pressure is higher than the pressure in the space above the ceiling, part of the air in the room can flow into the space above the ceiling even if the fan is stopped.

A perforated plate may be used as the ventilation body. By preparing a plurality of perforated plates having different aperture ratios, that is, different air permeability, and appropriately selecting and installing them, or by using a perforated plate whose aperture ratio can be adjusted, The amount of air flowing into the space above the ceiling through the ventilator can be easily adjusted.

Moreover, you may comprise a ventilation body from a filter and a perforated plate. As a result, dust in the air passing through the ventilator is collected by the filter, reducing the load on the filter inside the fan filter unit and preventing dust from the space above the ceiling from entering the room. it can. Furthermore, by adjusting the air permeability of the ventilation body with the perforated plate, the amount of air flowing from the room to the space above the ceiling via the ventilation body can be easily adjusted.

Preferably, the ventilator has a pressure in the room that is 0.2 mm Ac! When it is higher than 1.5 mm Aq, the total amount of air flowing from the room through the ventilator to the space above the ceiling is the total amount of air that the fan filter unit sends from the space above the ceiling into the room. It has air permeability that is 5% to 15% of the air volume. Thus, it is possible to effectively suppress the generation of the swirling airflow in the room while maintaining the cleanliness in the room. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an overall structure diagram of a clean room system using the clean room device of the present invention, FIG. 2 is a perspective view of a ceiling of a room of the clean room device of FIG. 1, and FIG. FIG. 4 is a perspective view, FIG. 4 is a sectional view of a clean room apparatus according to the third embodiment, and FIG. 5 is an exploded view of a bending member in the clean room apparatus according to the third embodiment. FIG. 7 is a diagram showing the relationship between the difference between the air pressure in the room of the clean room apparatus and the air pressure in the space above the ceiling, and the amount of air flowing through the ventilation body in the embodiment of the present invention. FIG. 8 is a schematic diagram of the airflow in the room of the clean room device according to the embodiment, and FIG. 8 is a diagram illustrating the dust concentration in the room of the clean room device according to the embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of a clean room apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram of a clean room system 11 using a clean room device 15 according to the first embodiment of the present invention. As shown in the figure, a plurality of fan filter units 14 are arranged on the ceiling 12 of the room 10 of the clean room device 15. The air in the space 16 above the ceiling of the clean room device 15 is sent into the room 10 while being purified by the fan filter unit 14. The air sent into the room 10 flows into the underfloor space 20 through the grating floor 18 together with the dust in the room 10, is cooled and dried by the drying cooling coil 21, and then passes through the return space 22. And return to the space above ceiling 16. Part of the air in the underfloor space 20 of the clean room device 15 is sent to the air conditioner 26 via the return air duct 2 and mixed with fresh air from the outside air intake duct 28 by the air conditioner 26. After the temperature and humidity are adjusted to predetermined values, the air is sent to the space 16 above the ceiling via the air supply duct 30. The air sent to the space 16 above the ceiling is sent into the room 10 while being purified again by the fan filter unit 14. Another part of the air in the underfloor space 20 is exhausted to the outside of the clean room system 11 through the exhaust duct 32.

FIG. 2 is a perspective view of the ceiling 12 of the room 10 of the clean room device 15. Room 10 Heaven In well 12, ceiling frames 36 are installed in a grid pattern. In the lattice space formed by the ceiling frame 36, a plurality of fan fill units 14 are arranged at intervals. The fan filter unit 14 has a casing, a fan, and a filter. By driving the fan, air is sucked into the casing from the space 16 above the ceiling, and the air is collected by the dust trap attached to the lower surface of the casing. It is configured to feed into the chamber 10 while removing dust with the collecting filter.

Ventilation body 40 is installed in an empty grid space where fan fill unit I 4 is not installed in the grid space formed by ceiling frame 36. The ventilation body 40 is composed of a filter 42 and a perforated plate 44 as shown in FIG. The filter 42 is, for example, a nonwoven fabric made of a fibrous material (for example, glass fiber) folded in an accordion shape. When air containing dust is passed through the filter 42, the dust is collected by the fibers inside the filter 42, and the air is cleaned.

The perforated plate 44 has holes uniformly formed on the entire surface of the plate, and the aperture ratio of the perforated plate 44 is determined in consideration of the air permeability of the ventilation body 40. For example, when the air pressure in the chamber i 0 is higher than the air pressure in the space 16 above the ceiling by 0.2 mm Aq to 1.5 mm A q, the air vent 40 The total air volume of the air flowing into the space 16 above the ceiling through 0 is 5% to 15% of the total air volume of the air sent into the room 10 by the fan filter unit 14 It is preferable to have air permeability for the following reasons. That is, if the air permeability of the gas 40 is too small and the air volume of the air flowing from the inside of the room 10 to the space 16 above the ceiling via the air body 40 is too small, Dust accumulates in the chamber 10 because a swirling airflow is generated. Conversely, if the air permeability of the ventilation body 40 is too large and the amount of air flowing from the room 10 to the space 16 above the ceiling through the ventilation body 40 is too large, the fan filter unit 14 Since the clean air sent into the room 10 flows directly into the space 16 above the ceiling, the efficiency of cleaning the inside of the room 10 deteriorates. The ventilation body 40 may be any as long as it has a necessary air permeability. For example, only a filter whose permeability is adjusted by selecting the type and thickness may be installed as the ventilation body 40. Alternatively, only a perforated plate whose aperture ratio has been adjusted to obtain appropriate air permeability May be placed.

The aperture ratio of the perforated plate 44 can be adjusted by, for example, configuring the perforated plate 44 with two multi-hole plates, one of which can slide, and adjusting the degree of overlap between the holes of both perforated plates. it can. According to this, the aperture ratio of the perforated plate 44 can be easily adjusted so that the air permeability of the ventilation body 40 is appropriate according to the scale and cleanliness of the clean room apparatus 15. Furthermore, even after the completion of the clean room device 15, the aperture ratio of the perforated plate 44 can be easily changed.

The ventilation body 40 is not limited to the above-described perforated plate 44 and the filter 42. As long as it has appropriate air permeability, for example, a slit plate or a fan filter unit 14 whose operation has been stopped may be used as the air body 40.

The operation of the clean room apparatus 15 according to the first embodiment of the present invention configured as described above will be described.

The fan of fan filter unit 14 is driven to send clean air into room 10. This causes a downward airflow from the ceiling 12 to the grating floor 18 under the fan filter unit 14, and most of the air in the room 10 is mixed with the dust through the grating floor 18. Flow into space 20. As described above, the air that has flowed into the underfloor space 20 returns to the space above the ceiling 16 except for some air exhausted outside the clean room system 11, and is purified again by the fan filter unit 14. While being sent into room 10.

By sending air into the space above the ceiling 16 and the room i 0, the pressure in the room 10 becomes higher than the pressure in the space above the ceiling 16. As a result, an upward airflow is generated in a region immediately below the ventilation body 40 in the room 10, and a part of the air in the room 10 flows into the space 16 above the ceiling via the ventilation body 40. Therefore, unlike the conventional case, no swirling airflow is generated in the region below the empty lattice space, and dust does not stay in the chamber 10.

As described above, in the clean room device 15 of the first embodiment, the ventilation body 40 including the filter 42 and the perforated plate 44 is installed in the empty lattice space where the fan filter unit 14 is not installed. The difference between the air pressure in the room 10 and the air pressure in the space above the ceiling 16 causes the room 10 Part of the air inside flows into the space 16 above the ceiling via the ventilation body 40. As a result, the dust is removed without staying in the chamber 10, so that the inside of the chamber 10 can be made highly clean. When a part of the air in the chamber 10 flows into the space 16 above the ceiling via the ventilation body 40, dust in the air is collected by the filter 42 of the ventilation body 40. As a result, the amount of dust collected on the filter in the fan filter unit 14 is reduced, and the life of the filter in the fan filter unit 14 can be extended.

A fan may be provided above the ventilation body 40, and the fan may be driven to send the air in the space 16 above the ceiling into the room 10. This allows the filter 42 to have the same effect as the filter of the fan filter unit 14, and can cope with a case where high cleanliness is required in the region below the ventilation body 40.

In the above-described first embodiment, the ventilation body 40 is installed in an empty lattice space where the fan finole unit 14 is not installed in the lattice space of the ceiling frame 12, but the present invention is not limited to this. . For example, the ventilation body 40 may be provided in a space facing the side wall or the pillar in the ceiling 12.

In the above-described first embodiment, the air in the room 10 flows to the space 16 above the ceiling due to the pressure difference generated between the room 10 and the space 16 above the ceiling by the fan filter unit 14. However, the present invention is not limited to this. For example, a fan may be provided above the ventilation body 40, and the air in the room 10 may be sucked into the space 16 above the ceiling by driving the fan. This makes it possible to easily adjust the amount of air flowing from the room 10 to the ceiling space 16 by adjusting the fan drive without adjusting the aperture ratio of the perforated plate 44. it can. Therefore, the fans in some fan filter units 14 out of the plurality of fan filter units 14 arranged on the ceiling 12 are operated in reverse, and the air in the room i 0 is removed from the air above the ceiling i 6 The same effect as in the above-described embodiment can be obtained also by sucking into the air. Hereinafter, a clean room apparatus 15 in that case will be described as a second embodiment.

In the clean room apparatus 15 according to the second embodiment of the present invention, fan filters 14 are installed in all lattice spaces of the ceiling frame 36 on the ceiling 11 shown in FIG. I do. This fan filter unit 14 is a blow-off operation in which clean air is sent from the space 16 above the ceiling into the room 10 by operating the fan in a normal direction, and an air in the room 10 is operated by operating the fan in the reverse direction. It is possible to switch between the suction operation that sucks into the space above the ceiling 16 and. Other configurations in the second embodiment are the same as those in the first embodiment, and a description thereof will be omitted.

The operation of the clean room apparatus 15 according to the second embodiment of the present invention configured as described above will be described.

A predetermined number of fan fill units 14 perform the blowing operation, and the remaining fan fill units 14 perform the suction operation. The number of fan filters 14 that perform the blowing operation and the suction operation is determined in consideration of the ratio between the air volume of the air sent into the room 10 and the air volume of the air sucked into the space 16 above the ceiling. For example, as described in the first embodiment, the air pressure in the room 10 is 0.2 mm Ac! When it is higher than 1.5 mm A q, the total airflow from room 10 to ceiling 16 is 5% of the total airflow from ceiling 16 to room 10 It is preferably 15%.

As described above, in the clean room device 15 of the second embodiment, a predetermined number of fan fill units 14 perform the blowing operation, and the remaining fan fill units 14 perform the suction operation. Part of the air in 10 is sucked into the space 16 above the ceiling. As a result, the dust does not stay in the chamber 10 but is collected by the filter in the fan filter unit 14, and the cleanliness of the air in the chamber 10 can be increased.

The dust collected at the fan fill unit 14 will not be scattered again even if the direction in which air passes through the filter changes. Therefore, the blow-out operation and the suction operation of the fan-fill unit 14 can be freely switched according to a change in the situation. Thereby, it is possible to cope with the change of the room 10.

In the above-described second embodiment, the fan filter units 14 are installed in all the lattice spaces defined by the ceiling frames 36 on the ceiling 12, but the present invention is not limited to this. For example, if fan filters 14 are spaced Also, by performing the suction operation with some fan fill units 14 and the blow-out operation with other fan units i 4, the cleanliness of the air in the room 10 can be increased. .

A clean room apparatus 15 according to a third embodiment of the present invention will be described with reference to FIGS. The same members as those in the first embodiment described with reference to FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 4, a curved member 68 is provided at a butt portion 66 between the peripheral portion of the ceiling 12 and the side wall portion 6 of the chamber 10 composed of the side wall and the pillar. The curved member 68 may be provided as a part of the ceiling 12 or the side wall portion 64, or may be provided as an independent member connecting the ceiling 12 and the side wall portion 64. The ceiling frame 36 is supported by hanging bolts 13.

As shown in FIG. 5, the bending member 68 is formed of a curved perforated plate 70, a curved slide plate 7, and a curved filter 74. The curved perforated plate 70 faces the chamber 10, the curved filter plate 74 faces the return space 22, and the curved slide plate 72 is located between the curved perforated plate 70 and the curved filter 74. I do. The curved perforated plate 70 includes a bottom plate 70 B in which a large number of holes 70 A are formed uniformly, a guide plate 76 formed on a pair of opposed side edges, and another pair of opposed side edges. It is formed from the stove plate 78 formed in the above. The curved slide plate 72 also has a large number of holes 72A. By sliding the curved slide plate 72 in the direction of the arrow 80 while guiding the curved slide plate 72 to the guide plate 76, the overlapping manner of the hole 7OA and the hole 72A is adjusted, and the above-described ventilation member 4 is formed. Similarly to 0, the aperture ratio of the curved member 68 can be adjusted. The curved filter 74 has the same structure as the filter 42 of the ventilation body 40, collects dust in the air passing through the curved member 68, and collects the dust in the chamber 10 and the return space 22. To prevent the user from moving between The curved filter 74 is held by a plurality of curved support plates 81, and the curved support plate 81 is fixed by a set screw 81A whose front end is screwed into a hole 70C formed in the curved porous plate 70. You.

The operation of the clean room apparatus 15 according to the third embodiment of the present invention configured as described above will be described. The fan of fan filter unit 14 is driven to send clean air into room 10. The air sent from the fan filter unit 14 near the periphery of the ceiling 12 flows downward along the side wall portion 64. A curved member 68 is arranged at the abutting portion 66 between the side wall portion 64 and the ceiling 12 so that the abutting portion 66 is rounded, so that the descending airflow is curved by the curved member 68. Flows smoothly along. As a result, as compared with the structure in which the butted portions 66 are angular, a swirling airflow is less likely to be generated in the peripheral region of the ceiling 16, so that dust can be prevented from staying in the peripheral region of the ceiling 16. The cleanliness in the room 10 can be increased. Further, since the curved member 68 is provided with air permeability, the curved member 68 has the same function as the above-described ventilator 40. That is, a part of the air in the peripheral area of the ceiling 12 in the room 10 flows to the return space 22 via the curved member 68 and returns to the space 16 above the ceiling. Thereby, the generation of the swirling airflow in the peripheral region of the ceiling 12 in the room 10 can be further suppressed, and the cleanliness in the room 10 can be improved in combination with the function of the ventilation body 40. Example

An embodiment of the clean room apparatus of the present invention will be described below.

A ceiling frame 36 having 72 grid spaces was provided on the ceiling 12 of the room 10 as shown in FIG. Of these grid spaces, fan filter units 14 are installed in 18 grid spaces, and the other 54 grid spaces, that is, empty grid spaces, are composed of only filters 42. Gas 40 was installed. Width 0.6 0 !, length 1.2 11, Ri height 0. 3 m Der, the fan filter Interview Knitting Bok which can be fed air 9 6 0 m ³ / h, file Nfiru evening Yuni' DOO Used as i4. ULPA (Ultra Low Penetration Air) filters were used as filters in fan filters 14 and filters 42. Room 10 had a height of 3.5 m, underfloor space 20 had a height of 4 m, and space above ceiling ί6 had a height of 3.2 m.

Next, the operation of the embodiment configured as described above will be described.

Figure 6 shows the difference between the air pressure in the room 10 and the air pressure in the space 16 above the ceiling, FIG. 7 is a relationship diagram between the air volume of air flowing into a space 16 above the ceiling via 0 and FIG. In the figure, the solid line shows the results when the ULPA filter was used as described above, and the dashed line shows the results when the PTFE filter (an ultra-high performance air filter using polytetrafluoroethylene filter material) was used as the fan filter unit. 14 shows the results of a comparative example in which the filter in 14 and the filter 42 were used. Here, the amount of air flowing from the room 10 to the space 16 above the ceiling through one lattice space is shown.

As shown in FIG. 6, as the pressure difference between the room 10 and the space 16 above the ceiling is smaller, the amount of air flowing from the room 10 to the space above the ceiling 16 via the ventilator 40 is smaller. The larger the pressure difference, the larger the air volume. In this embodiment, when the air pressure in the room 10 is higher than the air pressure in the space 16 above the ceiling by 0.2 mm Aq to 1.5 mm Aq, the inside of the room 10 is efficiently cleaned. . That is, when the pressure difference was too small, almost no air flowed from the inside of the room 10 to the space 16 above the ceiling, and a swirling airflow was generated in the room 10, causing dust to stay in the room 10. Conversely, when the pressure difference is too large, much of the clean air sent from the fan filter unit 14 into the room 10 flows into the space 16 above the ceiling via the ventilator 40, and the inside of the room 10 is cleaned. Was not performed efficiently.

When the air pressure in the room 10 is higher than the air pressure in the space 16 above the ceiling by 0.2 mm Aq to 1.5 mm Aq, the ceiling from the room 10 through all the filters 42 The total airflow of the air flowing into the upper space 16 was 5 to 15% of the total airflow of the air that all fan filter units 14 sent from the space 16 above the ceiling into the room 10. . Also, as can be seen from FIG. 6, by changing the type of the filter 42, the amount of air flowing from the room 10 to the space 16 above the ceiling via the filter 42 could be easily adjusted.

The operation of the present embodiment when the air pressure in the room 10 is higher than the air pressure in the space 16 above the ceiling by 0.25 mmAq will be described below.

FIG. 7 is a schematic diagram showing the result of measuring the flow of air in the room 10 of the clean room device 15. In the figure, the direction of the arrow indicates the direction in which the air flows, and the size of the arrow indicates the flow velocity of the air. As shown in the figure, a strong downdraft was generated below the fan filter unit 14. The dust in the air in this area is Was removed out of chamber 10 via. On the other hand, an updraft was generated immediately below the ventilation body 40. Part of the air that the fan filter unit 14 sent into the room 10 flows into the space 16 above the ceiling via the ventilation body 40, and the dust in the air is collected by the filter 42. As described above, by installing the ventilator 40 in the empty lattice space where the fan fill unit 14 is not installed, dust in the air in the room 10 is removed without staying in the room 10. Was done. Fig. 8 shows the result of measuring dust concentration (the number of dust per cubic foot) at measurement positions B, C, and D in chamber 10 by artificially generating dust at point A in Fig. 7. FIG. The horizontal distances from measuring point B, C, and D from point A are 0.6 m, 1.2 m, and 1.8 m, respectively. The measurement was made at each point of 2.7 m, 2.4 m, 2.1 m, 1.8 m and 1.5 m. The measurement results according to the present example are indicated by circles, and the measurement results according to the comparative example in which a closing plate is installed in the empty grid space instead of the filter 42 are indicated by crosses.

As shown in the figure, the dust concentration in the air in the chamber 10 in the present embodiment in which the filter 42 was installed in the empty grid space was almost the same as the comparative example in which the obstruction plate was installed in most measurement positions. Less than half. As described above, by installing the ventilation body 40 in the empty grid space where the fan filter unit 14 is not installed, the cleanliness in the room 10 can be increased.

Industrial applicability

As described above, according to the clean room apparatus of the present invention, the fan filter units are arranged at intervals on the ceiling of the room, and the ventilator is installed in the empty lattice space where the fan filter unit is not installed. Then, a part of the room air is allowed to flow to the space above the ceiling through the ventilator. This makes it possible to prevent the generation of swirling airflow in the area below the empty lattice space in the room, even if the fan-filled units are placed at intervals, so that dust can be prevented from staying in the room. Cleanliness can be increased.

Claims

The scope of the claims

1. A room with a ceiling,

A fan-fill unit that is installed on the ceiling and sends clean air from the space above the ceiling into the room;

A ventilator installed on the ceiling,

Has,

A part of the air in the room flows into the space above the ceiling via the ventilation body due to a difference between the air pressure in the room and the air pressure in the space above the ceiling.

A clean room device characterized by that:

2. The clean room device according to claim 1, wherein the ventilation body is a filter.

3. It further has a fan installed above the ventilation body,

Activating the fan to send air from the space above the ceiling through the filter into the room, blowing operation, and operating the fan in reverse to remove a part of the air in the room through the filter. Sucking into the space above the ceiling via a suction operation.

3. The clean room device according to claim 2, wherein:

4. The clean room device according to claim 1, wherein the ventilation body is a perforated plate.

5. The clean room apparatus according to claim 1, wherein the ventilation body includes a filter and a perforated plate.

6. It further has a fan installed above the ventilation body,

Activating the fan to send air from the space above the ceiling into the chamber through the filter; blowing operation; and inverting the fan to allow a portion of the air in the chamber to pass through the filter. Performing at least one of the following operations: The clean room device according to claim 5, wherein:

7. When the air pressure in the room is higher than the air pressure in the space above the ceiling by 0.2 mmAq to 1.5 mmAq, the ventilator passes through the ventilator from within the chamber. It has air permeability such that the total air volume of the air flowing above the ceiling is 5% to 15% of the total air volume of the air that the fan filter unit sends from the space above the ceiling into the room. The clean room device according to claim 1, wherein: