JPH086184Y2 - Underfloor airflow control structure in clean room - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a technique for easily adjusting the air volume of a downflow type clean room using an underfloor space.

[Conventional technology]

As is well known, the down-flow type clean room blows clean air from the ceiling surface and sucks indoor air into the underfloor space through the perforated floor surface. A HEPA filter layer is installed on the ceiling surface to supply the space above the ceiling. Plenum method,
A method of arranging a required number of fan filter units on the ceiling surface is often used. In any case, a part or all of the air sucked into the underfloor space through the porous floor surface is supplied as return air to the room from the HEPA filter layer on the ceiling surface again with or without passing through the air conditioner.

In order to carry out such air circulation, it is necessary to provide a return air intake port at a specific place (usually at one place, at most several places) in order to take in return air from the underfloor space having a two-dimensional spread. It is normal. In addition, it is usual to form zones having different cleanliness in the clean room according to the layout of the work in the clean room.

When zones with different degrees of cleanliness are formed without a partition wall in one clean room space, as shown in Fig. 1, the high cleanliness area (for example, class 100) has a ceiling surface H
It is common practice to arrange the EPA filters 1 densely and to arrange the HEPA filters 1 roughly in a relatively low clean area (for example, class 1000). In FIG. 1, 2 is a porous floor surface, 3 is an underfloor space, 4 is a return air intake, 5 is an air conditioner, and 6 is an air supply plenum above the ceiling. In such a case, since the area of the HEPA filter is different between the highly clean area and the low clean area, the air blowing area is also different. For this reason, the air volume descending toward the floor surface differs between the highly clean area and the low clean area, and the former is larger. Generally, the grating material 7 is used for the porous floor surface 2. However, if the grating 7 is installed over the entire area where the air volume is different as described above, the amount of air sucked into the underfloor space 3 from the side close to the return air intake 4 is increased. Since there are many, problems occur. For this reason, this grating material is installed in the entire area in the highly clean area, but in the low clean area, since the air volume is small, the opening of the floor is reduced and a partial suction port 8 is provided.

[Problems to be solved by the invention]

In a clean room in which zones with different cleanliness coexist as described above, the airflow that descends in the clean room tends to incline near the floor due to the difference in the opening area of the floor and the ventilation resistance. It is necessary to adjust the air volume of the air to be used. Conventionally, in such a case, as shown in FIG. 2, the air resistance is adjusted by inserting a punching metal plate 9 having a required aperture ratio into the lower layer of the grating material 7.

However, it is difficult to calculate what kind of aperture ratio should be used for this punching metal plate 9, and it is the actual situation that it is done at the site. That is,
Remove the heavy grating material 7 and attach the punching plate 9, install the grating material 7 and operate the clean room, measure the flow line of the suction flow, and confirm the appropriateness until the proper flow line is obtained. This is a troublesome work of repeatedly replacing the punching plates 9 having different aperture ratios.
Not only in the case of a new clean room, but also in an existing clean room, the resistance of the floor must be adjusted every time the line is changed or the usability is changed.

As described above, in the downflow type clean room, there is a problem that the work of adjusting the air resistance on the floor is very troublesome. The present invention aims to solve this problem easily.

[Means for solving problems]

The present invention solves this problem with an extremely simple operation of hanging the curtain in the underfloor space. That is, the present invention is characterized in that in a down-flow type clean room in which indoor air is sucked into the underfloor space through a perforated floor surface, a sheet-like curtain is hung in the underfloor space to provide resistance to the airflow flowing in this space. It provides an underfloor airflow control structure for a clean room. It is most convenient and reliable to hang the curtain on the joists that support the floor material, and it is preferable to hang it at a place where the aperture ratio of the porous floor surface changes.

[Action]

When the curtain is hung while the air sucked into the underfloor space is flowing toward the return air intake, the curtain gives a resistance to the air flow. Therefore, by appropriately adjusting the location where the curtain is hung and the size of the curtain, it is possible to properly adjust the intended streamline of the intake airflow above the floor surface. Increasing or decreasing the curtain area is a simple and easy task, and can be easily installed by using joists. Also, the selection of the mounting position is not particularly limited. Therefore, the adjustment work can be performed much more easily than the conventional air flow adjustment using punching plates having different aperture ratios.

〔Example〕

FIG. 3 shows an embodiment of the underfloor curtain construction method according to the present invention, in which the same grating material 7 as described in FIG. 1 exists at a location corresponding to a high clean area, and a low clean area. In the floor structure in which the suction port 8 is provided at a position corresponding to the above, and the blind floor material 10 exists between the suction port 8 and the grating material 7, the state where the curtain 11 is hung under the floor is shown. ing. Also in this example, the air in the underfloor space 3 is the first
As in the figure, it is unidirectionally sucked into the return port on the right side of the figure. In the illustrated example, the curtain 11 is hung in the underfloor space near the boundary between the highly clean area and the low clean area.

As described above, it is necessary to reduce the air volume sucked from the low-clean area where the blind floor material 10 and the suction port 8 on the left side of the grating material 7 are sucked into the underfloor space 3 through the grating material 7. By hanging the curtain 11 as in this example, the curtain 11 becomes a resistance and the amount of air sucked from the low clean area can be reduced. Then, the adjustment of the air volume only needs to adjust the increase or decrease of the curtain area. Further, the curtain 11 may be attached using the joists 12 that support the floor material. That is, in order to form a floor of a clean room, generally, the hauling material 13 is stretched using the posts 14, and the joists 12 are placed on the hauling material 13.
The floor material is installed on the joist 12, but in the present invention, it is only necessary to fix the upper edge of the curtain 11 to the joist 12. FIG. 4 is an enlarged view of this mounting state, and shows an example in which the upper edge of the curtain 11 is fixed to the side surface of the joist 12 using screws 15. Thickness of curtain material is 0.1
It is convenient to use a vinyl sheet of about 0.5 mm.

Although the curtain 11 is shown only at one place in the illustrated example, it may be hung separately at several places or a perforated curtain may be used.

[Effects] As described above, according to the present invention, when a plurality of zones having different cleanliness coexist in a down-flow type clean room, the distribution of the intake air volume to the underfloor space is adjusted simply by hanging the curtain in the underfloor space. Since it can be done, it is a much easier task compared to the case where air resistance is given to the conventional flooring material, and the material used is also inexpensive and highly flexible, so it is simple and easy in a short construction period depending on the convenience of clean room use such as line change. The air volume of the floor suction airflow can be adjusted.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a general clean room in which zones with different cleanliness coexist, FIG. 2 is a sectional view showing a conventional air flow rate adjusting method using a floor resistance method, and FIG. 3 is an underfloor according to the present invention. FIG. 4 is a schematic enlarged sectional view showing an example of the curtain construction method, and FIG. 4 is a partially enlarged sectional view of FIG. 1 ... HEPA filter layer, 2 ... perforated floor, 3 ... underfloor space, 4 ...
… Return air intake, 5 …… Air conditioner, 6 …… Attic space, 7 …… Grating material, 8 …… Suction opening, 9 …… Punching board, 10 …… Blind floor material, 11 …… Curtain, 12 ...... Genta, 13 …… Draft material, 14 ……
Post, 14 ... bis.

Claims (3)

[Scope of utility model registration request] 1. A down-flow type clean room in which indoor air is sucked into a space under a floor through a perforated floor surface, and by suspending a sheet-shaped curtain in the space under the floor, a resistance is given to an air flow flowing in the space. An underfloor airflow control structure for a clean room. 2. The underfloor airflow control structure according to claim 1, wherein the curtain is hung on a joist supporting a floor material. 3. The underfloor airflow control structure according to claim 1, wherein the curtain is hung at a place where the aperture ratio of the porous floor surface changes.