JPH0437614Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a filter unit for forming a highly clean area in a clean room or the like in a free space with a lower degree of cleanliness.

[Background of the invention and conventional problems]

In an industrial clean room, it may be necessary to create only a specific area of the free space within the room into a clean area higher than the free space. For example, in a semiconductor factory, original plates such as wafers, semi-finished products, processed products, etc. flowing from various working machines and stockers are transported using trolleys or automatic transport in a free space where workers can freely pass through. In order to prevent contamination of such products, these transport paths must be maintained at the same high level of cleanliness as the process zone in which the work machinery is operating. It is necessary to do so.

Generally, the volume of the space provided for such product transportation is very small compared to the volume of the entire clean room. This transport space is not a space that is closed off from the surroundings, but is generally a space that is exposed indoors. In order to maintain such a transfer space at a high level of cleanliness, it is necessary to increase the cleanliness of the entire clean room, or to locally maintain a high level of cleanliness only in the transfer space within the free space.

Although it is possible to improve the cleanliness of the entire clean room in the former case, there is a problem in that this increases the size of the air processing equipment. Even if the overall cleanliness of the room is improved, the presence of workers is always a source of contamination, and there is a problem in that contamination occurs between the workers' passage and the transport space.

On the other hand, in the case where only the conveyance path is maintained at a locally higher level of cleanliness than the free space, as in the latter case,
In vertical laminar flow clean rooms, the use of air curtains and eyelids (hanging walls) has been proposed. However, if air curtains are formed on both sides of the conveyance path to prevent contamination between the free space that serves as the worker's passage and the conveyance path, the local high-speed airflow caused by this air curtain may cause This may cause the airflow to curl up,
There is a problem in that it becomes a disturbance factor in adjusting the indoor temperature and humidity.

Furthermore, when hanging eyelids or vinyl curtains, the conveyance path cannot be sufficiently surrounded unless the eyelids or vinyl curtains hang down as far as possible, so there is a problem that the presence of the eyelids becomes a hindrance to the work. When attempting to maintain a locally higher level of cleanliness in only the conveyance path than in the free space, it is necessary to change the air blowing equipment in accordance with changes in the production line, and at the same time, the air curtains and eyelids must also be adjusted accordingly. There is a problem that follow-up workability accompanying line changes is poor.

[Purpose of invention]

This invention enables local high-cleanliness areas maintained at a higher level of cleanliness than free space, such as product transportation paths, within a clean room, to be maintained at a higher level of cleanliness than in free space, without using conventional air curtains or eyelids. The purpose of this is to form the system so that it can be freely and easily adapted to changes in the system.

[Structure of the idea]

The gist of the present invention, which aims to achieve the above-mentioned object, is to provide a casing having a rectangular opening on the lower surface, and a casing extending over the opening of the casing.
A filter unit consisting of a HEPA filter layer, wherein the HEPA filter layer is composed of a horizontal part parallel to the horizontal plane of the opening and an inclined part inclined with respect to the horizontal plane, and the central part of the opening is The horizontal portion closes the opening, and the inclined portion slopes downward from at least one edge of the opening toward the central portion, and
A filter unit is used in which the inclined portion and the horizontal portion are connected to each other.

The filter unit of the present invention can be used, for example, when forming a transport passage in a free space in a clean room, the filter unit can be placed on the ceiling surface corresponding to the transport passage so that the horizontal part and the inclined part of each HEPA filter layer are mutually connected. By installing them in a continuous manner, this conveyance passage space can be easily formed into a highly clean area with a higher cleanliness area than the free space, and the connection between the free space and the conveyance passage can be easily formed. Contamination caused by airflow can be prevented.

In the filter unit of the present invention, the HEPA filter layer is horizontal in the center, but slopes upward at the sides, so that the clean air flow blown out from the filter unit slopes downward as it approaches the floor surface. Forms a widening airflow pattern.

The present invention will be explained in detail below with reference to the embodiments shown in the drawings.

FIG. 1 is for explaining the usage condition of the filter unit of the present invention, in which 1 shows the ceiling of a clean room, and 2 shows the floor of the same. The filter unit of the present invention is used to form a specific highly clean area 4 with a high level of cleanliness, such as a passageway for transporting products, within a free space 3 in a clean room. For this purpose, sufficient
Filter unit 5 with HEPA filter area
is arranged horizontally on the ceiling surface 1 corresponding to this highly clean area, and clean air is blown downward from this filter unit 5.

This filter unit 5 consists of a casing 6 having a rectangular opening on the lower surface, and a HEPA filter layer stretched across the opening of the casing.
This HEPA filter layer is composed of a horizontal part 7 parallel to the horizontal plane of the opening and an inclined part 8 inclined with respect to the horizontal plane, and the central part of the opening is closed by the horizontal part 7. and the inclined portion 8 has a downward slope from at least one edge of the opening toward the central portion, and
The inclined portion 8 and the horizontal portion 7 are connected to each other to form an air blowing surface.

In the example shown in FIG. 1, the horizontal portion 7 of the HEPA filter has a width slightly larger than the width of the high-purity area 4, and the inclined portions 8 are connected to both sides of the horizontal portion 7.
This inclined portion 8 has an upward slope toward the side end. And this horizontal part 7
The space inside the casing 6 behind the HEPA filter layer, which consists of a sloping section 8 and a sloping section 8, forms an air supply plenum 9. That is, the casing 6 is
A closed space is formed by the horizontal part 7 and the inclined part 8 of the HEPA filter, as well as the side plate and the top plate, and the primary filter 1 is placed in this closed space.
1 is supplied by a fan 10, the pressure of the supplied air is equalized in a closed space within the casing 6, and then the air is blown into the room from the blowing surface of the HEPA filter. Furthermore, in the example shown in Figure 1, the HEPA filter uses filters with equal pressure drop in both the horizontal part 7 and the inclined part 8. Therefore, the blowing flow velocity of both parts is substantially the same, and it is difficult to use in a normal clean room. It is preferable to set the blowing flow velocity to 0.4 to 0.5 m/s as adopted. The angle of inclination of the inclined part 8 depends on the ceiling height and the height and width of the high clean area 4, but it is 5~
It should be about 25°.

As a result, a vertical clean flow flows as a downflow toward the high cleanliness area 4 as shown in the airflow pattern in FIG. This inclined clean flow prevents the air in the free space 3 from entering the high clean area 4. In other words, the boundary between the inclined clean flow and the free space 3 slopes away from the highly clean area 4 as the airflow direction advances, so the air in the free space 3 is carried away from the highly clean area and the boundary Even if nearby contaminated air is caught in the inclined clean flow near the ceiling, it will be carried towards the free space 3 on the inclined clean flow, and will be prevented from being carried towards the highly clean area 4. .

Figure 2 shows that a conveyance passage 12 through which a trolley passes is formed as a highly clean area 4 in a free space 3 in a clean room by arranging the filter unit of the present invention in series on the ceiling surface. An example is shown in a two-dimensional view. 13 is a high cleanliness area where mechanical equipment etc. are present, and this process high cleanliness area 1
3, various products are conveyed through a conveyance path 12. In the present invention, by installing a filter unit 5 as explained in FIG. A maintained highly clean zone 4 is formed in which the conveying passage 12 is contained. The shaded area in FIG. 2 is the highly clean area 4, which is surrounded by the lateral inclined clean flow described above. In the present invention, a predetermined size of the horizontal part 7 and the inclined part 8 as described above is used.
By installing a HEPA filter in a casing of a predetermined size and making it into a unit, and by arranging these units in series, a planar strip is formed in the free space 3 with a predetermined width like the conveyance path 12. It is possible to form a zone in the highly clean area 4 that extends for a long time.
Examples of this unitization are shown in FIGS. 3 and 4.

FIG. 3 shows a typical external shape of the unit 5. As shown in the figure, the casing 6 has a flat rectangular shape, and has a simple outer shape with a HEPA filter stretched across its lower opening.
As explained in FIG. 1, the HEPA filter has a central horizontal portion 7 and sloped portions 8 on both sides thereof. More specifically, two opposing sides a and b of the rectangular horizontal portion 7 are aligned with the edge of the opening of the casing 6, and the other two opposing sides c and d are aligned from the edge of the opening of the casing 6 toward the center. from the two sides c and d of this horizontal portion 7 to the edge of the opening.
will be established. an inclined portion extending from side c to the side edge;
The sloped portions extending from side d to the other side edge may be symmetrical and have the same slope and width, but in some cases, the slope and width may be different.

FIG. 4 shows an example in which a strip-shaped clean air outlet is formed on the ceiling surface by arranging such units 5 in series. In this case, by arranging the units 5 having the shape shown in FIG. 3 in the same direction, that is, by arranging the sides c and d of the horizontal portion 7 in a straight line in all the units. By arranging them in series, a long belt-shaped clean air outlet can be formed. Further, when forming a T-shaped path, the inclined portion 8 at the T-shaped joint portion of the unit 5' may be shaped into a trapezoid so as to match the horizontal portion and the inclined portion of the other unit. Each unit 5 connected in this way
In this case, air may be supplied by a fan 10 as shown in FIG. 1, or as shown in FIG. It is also possible to supply air to each unit 5 by taking the following steps.

FIG. 5 shows a sloped portion 8 on only one side of the horizontal portion 7.
3 shows a filter unit 5 according to the invention similar to that of FIG. 3, except that . When these units are connected in the same direction, that is, when the units are connected so that the sides c, which are the boundaries between the horizontal part 7 and the inclined part 8, are in line with each other, only one side is in contact with the free space. It is possible to form a belt-shaped highly clean area. Therefore, it can be advantageously used in cases where the other side is connected to a highly clean area or is a wall surface.

FIG. 6 shows an example of a filter unit according to the invention in which the sloping portion 8 has a curved slope from the horizontal portion 7, again in this case the sloping portion is located at least one of the lower openings of the casing. It has a downward slope from the edge toward the center, and this sloped part and the horizontal part are still connected to each other, but since it is a curved slope, the width of the seat is A smoother airflow pattern can be created.

As described above, by using the filter unit of the present invention in series, it is possible to freely design a high-clean area within the free space of a clean room that has a higher cleanliness level than the free space. The high cleanliness zone that is created is maintained in its cleanliness by an airflow pattern of inclined clean flow that prevents contamination from within the free space. Therefore, it is particularly effective in industrial clean rooms where a product transportation path is provided in the free space within the clean room, and since it is unitized, it is easy to follow changes in the line. Since it is easy to manufacture and install, the above-mentioned objectives of the present invention can be effectively achieved.

[Brief explanation of the drawing]

Figure 1 is an airflow pattern diagram showing the basic principle for forming a highly clean area in free space using a filter unit according to the present invention, and Figure 2 is an airflow pattern diagram showing the basic principle for forming a highly clean area in a free space using the filter unit according to the present invention. Conceptual diagram showing a state in which a conveyance path is formed in a highly clean area, Part 3
The figure is a perspective view showing a typical overall shape of the filter unit according to the present invention, FIG. 4 is a perspective view showing the filter unit of FIG.
The figure is a perspective view showing another example of the filter unit according to the present invention, and FIG. 6 is a partial schematic sectional view for explaining another example of the inclined portion of the HEPA filter of the filter unit according to the present invention. 1... Ceiling surface, 2... Floor surface, 3... Free space,
4...High cleanliness area, 5...Filter unit, 6...
...casing, 7...horizontal part of HEPA filter, 8...slanted part of HEPA filter, 9...
Supply air plenum, 10... fan, 11... primary filter, 12... conveyance passage.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A filter unit consisting of a casing with a rectangular opening on the lower surface and a HEPA filter layer stretched across the opening of the casing is installed horizontally on the ceiling of a clean room. In the filter structure of the ceiling part to be arranged, the HEPA filter layer as the filter unit is composed of a horizontal part parallel to the horizontal plane and an inclined part inclined with respect to the horizontal plane,
A filter unit is used in which the center portion of the casing opening is closed by the horizontal portion, and the inclined portion slopes downward from at least one edge of the opening toward the center portion. Then, place multiple of these filter units on the ceiling surface corresponding to the aisle space in the clean room.
A ceiling filter arrangement structure that forms a passage space of a high cleanliness area within the free space of a clean room, characterized in that the horizontal and inclined parts of the HEPA filter layer are arranged in a continuous band shape. (2) The arrangement structure of filters in the ceiling according to claim 1 of the utility model registration, wherein the passage space is a passage space for transporting products.