JPH08210676A - Tunnel type clean room - Google Patents

Abstract

PURPOSE: To prevent the entrainment of dust, generated from workers positioned at a boundary area, into high-speed flow area by a method wherein a clean room is partitioned into the high-speed flow area and a low-speed flow area by a hanging wall and the high-speed flow area is provided with a fan filter unit while the low-speed flow area is provided with filter ducts having the section of an arc. CONSTITUTION: A tunnel type clean room is partitioned by a hanging wall 22 into a high-speed flow area (a), wherein a high degree of cleanness is necessitated, a boundary area (c) and a low-speed flow area (b). A filter unit 30 is arranged in the high-speed flow area (a) and a filter duct 80, having an arced section, is arranged in the low-speed flow area (b). In this case, the flow-out speed of the boundary area (c) between the high-speed flow area (a) below the hanging wall 22 and the low-speed flow area (b) is substantially equal to that of the high-speed flow area (a). Accordingly, high-speed laminar flow, flowing against production machines 29 installed on a floor, is formed in the high-speed flow area (a) while middle-speed and low-speed flows, having a uniform direction, are formed from the filter duct 80 having the section of an arc. According to this method, ascending air streams will never be generated in the boundary area (c) or the corners of a room and stabilized downward air stream can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel type clean room applicable to a dust-free room or a sterile room such as a semiconductor factory, a precision machine factory, a chemical manufacturing factory.

[0002]

2. Description of the Related Art For example, in a semiconductor factory, a VLSI
The need for ultra-cleanliness space has increased as a response to the sophistication of manufacturing technology that accompanies the higher integration and ultra-miniaturization of
A tunnel type clean room having a cleanliness of 00 is required.

There are a vertical laminar flow type clean room and a tunnel type clean room that meet this demand. In a vertical laminar flow type clean room, it is necessary to install a high-performance filter on the entire surface of the ceiling and control the temperature and humidity of the entire room, which may cause an imbalance in the temperature control of each production device in the room. was there.

On the other hand, the tunnel type clean room has an advantage that it is possible to control each working unit with high accuracy by dividing the area into clean areas. An example of this tunnel type clean room is disclosed in Japanese Patent Laid-Open No. 61-287422. This will be described with reference to FIG.

In the figure, 1 is a tunnel type clean room. In this tunnel-type clean room 1, a hanging wall 2 divides a high-speed basin A, a boundary basin C, and a low-speed basin B that require high cleanliness. A high-performance filter 3 is installed in the high-speed basin A. The high-performance filter 3 is attached to an air supply chamber 4 provided on the ceiling side in a tunnel-shaped room.

Below the high-performance filter 3, a production machine 6 disposed on the floor 5 of the clean room 1 is located.
Between the hanging wall 2 on the low speed basin B side and the ceiling 7, there is an air outlet 8
Is provided. The air outlet 8 includes two high-performance filters 9 and 10, an air supply chamber 11 that sends clean air to the both high-performance filters 9 and 10, and a high-performance filter that is located in the air supply chamber 11 and that extends from the hanging wall 2. 9 and a damper 12 provided on the upper part of 9.

The boundary area C is formed by the blowout from the high performance filter 9. According to this tunnel-type clean room 1, the clean air is flowed through the high-performance filter 3 over the entire area of the high-speed basin A in an approximately vertical downward direction by 0.3 to 0.4.
It blows out in a laminar flow at a speed of about m / sec, and in the low-speed basin B, the clean air is diffused through the high-performance filter 10 so that the average indoor descent speed is about 0.05 to 0.2 m / sec. It's blowing.

In the boundary area C, the damper 12 is operated to move the clean air substantially vertically downward to 0.3 to 0.4 m /
It is blowing at a speed of about sec. Since the high-performance filter 9 and the damper 12 form the same airflow as the airflow in the high-speed watershed A in the boundary area C, it is possible to prevent the inclusion of dust from the workers located on the boundary area C side. it can.

FIG. 11 is also the same as that of Japanese Patent Laid-Open No. 61-28274.
It is a tunnel type clean room described in Japanese Patent No. In this case, the high-performance filter 13 is installed on the ceiling side, and one air outlet 14 is provided with a boundary area 14a and a low-speed water area 14b. Even in this tunnel-type clean room, it is possible to prevent the inclusion of dust from the worker located on the boundary area C side as in the case of FIG.

[0010]

In the tunnel type clean room shown in FIG. 10, however, since the damper 12 adjusts the wind speed in the boundary region C, it takes time to adjust the damper 12 and the high performance filter 9 is used. , 10 are each formed by a straight line, and the angles formed by the high-performance filters 9, 10 have a considerably large angle.
A new boundary area is created by the air flow blowing from each of the ten. As a result, the boundary area C is likely to be displaced only by the width of the high-performance filter 9.

Further, in the tunnel type clean room shown in FIG. 11, since the dynamic pressure is applied from the high-performance filter 13 to the inside of the air outlet 14, the clean air is discharged from the boundary area 14a facing downward rather than the lateral low speed area 14b. It may be easier and faster than the flow velocity in the high-speed basin A. In that case, it is not possible to prevent the inclusion of dust from the worker located on the boundary area C side.

The present invention has been made to solve such a conventional problem, and an object thereof is to prevent dust from an operator located in the boundary area from being caught in a high-speed basin. To provide a tunnel type clean room.

[0013]

According to a first aspect of the present invention, a hanging wall divides a high-speed basin requiring a high degree of cleanliness from a low-speed basin, and a fan filter unit is provided in the high-speed basin.
A filter duct having an arcuate cross section is provided in the low-speed flow region.

According to the second aspect of the present invention, the fan filter unit provided in the high-speed basin is located at a height substantially equal to the lower end height of the hanging wall. According to the third aspect of the invention, the fan filter unit provided in the high-speed basin is vertically movable. According to the invention of claim 4, the fan filter unit provided in the high-speed flow region is provided with an axial flow type fan or a centrifugal fan and a filter.

According to the fifth aspect of the present invention, the blowing speed at the boundary between the high speed basin and the low speed basin below the hanging wall is substantially the same as that of the high speed basin. According to the invention of claim 6, in the filter duct having an arcuate cross section provided in the low speed region, the blowing speed of the area portion adjacent to the high speed region of the work area becomes lower as the distance from the high speed region increases.

(Operation) In the inventions of claims 1 to 6,
In the high-speed basin, a high-speed laminar flow flowing toward the production machine can be formed as in the conventional case, and in the low-speed basin and the boundary area, a medium-low speed flow having a uniform direction can be formed from the filter duct having an arc-shaped cross section.

Therefore, the rising airflow does not occur in the boundary area and the corners of the room, and a stable downward airflow is obtained in the room. According to the invention of claim 2, the pressure field in the vortex region due to the high-speed laminar flow to the production machine rises, and the dust concentration decay time in the vortex can be shortened. According to the invention of claim 3, the fan filter unit provided in the high-speed basin can be moved up and down according to the use.

According to the invention of claim 4, a high-speed flow can be easily formed. According to the inventions of claims 5 and 6, it is possible to prevent dust from being entrained by an operator in the high-speed basin.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the embodiments shown in the drawings.

FIG. 1 shows an embodiment of a tunnel type clean room according to claims 1, 4 to 6. In the figure, 21 is a tunnel type clean room. The tunnel type clean room 21 is divided into a high speed basin A, a boundary basin C and a low speed basin B, which require high cleanliness, by a hanging wall 22.

In the tunnel type clean room 21, a high performance filter unit 24 for blowing clean air into the tunnel type clean room 21 is attached to the ceiling 23 side, and a floor 25 is provided with punching metal which is wholly or partially perforated. Has been done. The ceiling space 26 and the underfloor space 27 communicate with each other via an air conditioner 28. A production machine 29 is arranged on the floor.

A fan filter unit 30 is arranged in the high-speed basin A. This fan filter unit 3
As shown in FIG. 3 and FIG. 4, ULPA is provided in the lower end opening 33 of the cylindrical unit body 31 having a square cross section.
A high performance filter 35 such as a filter or a HEPA filter is arranged.

At the center of the upper surface 37 of the unit body 31,
An intake opening 39 is formed, and an axial flow fan 41 is arranged in the intake opening 39. The axial flow fan 41 includes a bell mouth 43 fitted in the intake opening 39.
have. At the center of the bellmouth 43, a boss 45 is formed.
Are arranged, and the blades 47 are fixed to the outer periphery of the boss portion 45.

A motor 49 is connected to the boss portion 45,
The motor 49 is attached to the bell mouth 43 via the bracket 51.
It is fixed to. The boss portion 45 has a tapered airflow guide cover 5 protruding in the suction direction.
3 is installed. A plurality of straightening vanes 55, which protrude inward and suppress swirling of the swirling flow generated by the rotation of the axial flow type fan 41, are fixed to the upper part of the inner circumference of the unit main body 31.

A sound absorbing material 57 made of glass wool is mounted on the rectifying plate 55. Below the axial flow type fan 41 of the unit main body 31, a sound insulating plate 59 is arranged. The sound insulation plate 59 has a square shape, and its center is located below the axial flow fan 41.

A sound absorbing material 61 made of glass wool is mounted on the sound insulating plate 59, and the sound insulating plate 59 is fixed to the inner surface of the unit body 31 by a bracket 63.
At the center of the sound insulation plate 59, a square recess 65 is formed which is recessed downward. The inner peripheral surface of the recess 65 is an inclined surface 67 that inclines toward the bottom surface.

Below the sound insulation plate 59 of the unit body 31, a rectangular ring-shaped outer sound insulation plate 69 is arranged. The outer sound-insulating plate 69 is arranged so that the inner peripheral portion thereof overlaps the sound-insulating plate 59. A sound absorbing material 71 made of glass wool is attached to the outer sound insulating plate 69.

In FIG. 1, reference numeral 80 denotes a filter duct having an arcuate cross section. The filter duct 80 includes a high-performance filter such as a ULPA filter or a HEPA filter, and has a cross section of approximately 1/4 vertical elliptical arc depending on the wind speed ratio Va / Vb between the high speed basin A and the low speed basin B, the mounting pitch of the filter duct, and the distance x. The shape is changed to a substantially quadrilateral cross section, an arc shape, and a substantially quadrangular cross section.

Here, the curvature of the air outlet 81 is (1 /
If ρ) ₈₁ and the curvature of the air outlet 82 are (1 / ρ) ₈₂ , the following function is obtained. Va / Vb × α ・ 1 / x∝β × (1 / ρ) ₈₁ / (1 /
ρ) ₈₂ where α and β are coefficients. This is because the larger the Va / Vb, the larger the amount of airflow in the boundary region C, and the larger x, the larger the amount of airflow in the low speed basin B.

For example, when Va / Vb is large and x ≦ 2 ⁿ , the filter duct 80 has an outlet 81 toward the low speed basin B side.
The flow velocity is lower than that of the air outlet 82 to the boundary area C. Therefore, a resistor such as a punching plate is attached to the air outlet 81, or the folding density and the height of the high performance filter are changed, or the filter curvature of the air outlet 81 is made larger than that of the air outlet 82. By doing so, means such as increasing the area of the filter medium from the outlet port 82 relative to the outlet port 81 is applied.

Next, the operation of this embodiment will be described. By driving the air conditioner 28 to supply clean air to the fan filter unit 30, the high performance filter unit 24 and the filter duct 80, clean air is supplied to the tunnel type clean room 21. At that time, in the fan filter unit 30, after the air sucked from the intake opening 39 by the axial flow type fan 41 is made into a swirling flow, this swirling flow collides with the flow straightening plate 55 at the outer peripheral portion. The flow is suppressed and flows downward, passes between the sound insulation plate 59 and the outer sound insulation plate 69, reaches the high-performance filter 35, and is purified by the high-performance filter 35.
It is blown out at a high speed of about 3 to 0.4 m / sec.

On the other hand, clean air is blown out from the high-performance filter unit 24 at a low speed, which is an average indoor descent speed of about 0.05 to 0.2 m / sec. Further, in the filter duct 80, since the air outlet is formed by the entire surface filter, the blowout air velocity is different due to the difference in the pressure loss of each part filter without being affected by the dynamic pressure, and the high speed flow area A from the air outlet 82 is obtained. The clean air is blown out at a speed almost equal to the speed of, and 0.05 to 0.2 m / sec from the air outlet 81.
The clean air can be blown out at such a low speed that the indoor average wind speed is about the same.

Therefore, a downward stable airflow is formed between the high-speed watershed A and the boundary area C, and an ascending airflow is not generated. That is, the dust generated by the worker in the boundary area c is not caught in the high-speed flow area A. Further, unlike the conventional case, since the complicated operation of operating the damper is not required, it is easy to manage the tunnel type clean room.

In addition, since the filter duct 80 only needs to be installed in the boundary area c, the structure is simple. In the fan filter unit 30 described above, the axial flow type fan 4
A swirl flow is generated toward the outside of the axial flow type fan 41 by the use of No. 1 and this swirl flow is generated in the plurality of straightening vanes 55 arranged in the upper part of the inner circumference of the unit body 31 in the outer peripheral part. The collision is suppressed, the flow is directed downward, and the air is blown out into the room through the high-performance filter 35, so that the discharge air velocity distribution from the high-performance filter 35 can be made uniform.

Further, since it is not necessary to change the direction of the air flow by the rectifying porous plate or the like, it is possible to prevent the discharge resistance from increasing. Further, the sound insulation plate 59 arranged between the axial flow type fan 41 and the high performance filter 35 can surely insulate noise generated from the axial flow type fan 41. Further, in the above-described fan filter unit 30, since the unit main body 31 has a square cross section and the centers of the axial flow type fan 41 and the square-shaped sound insulation plate 59 are arranged in the center thereof, the high performance filter 35 has the same shape from the four sides. The air is discharged under the condition, and the distribution of the discharge wind speed from the high-performance filter 35 can be made more uniform.

Furthermore, a square recess 65 is formed in the center of the sound insulation plate 59, and the inner peripheral surface of the recess 65 is inclined toward the bottom surface, so that it collides with the bottom surface of the recess 65. The air is guided by the inclined surface 67 and smoothly flows toward the outside without disturbing the air flow.
It is possible to make the discharge air velocity distribution from No. 5 more uniform.
Further, in the fan filter unit 30 described above, since the inner periphery of the outer sound-insulating plate 69 is arranged below the sound-insulating plate 59 of the unit main body 31, the noise generated from the axial-flow type fan 41 directly affects the high-performance filter. It is possible to prevent reaching 35 and improve the sound deadening effect.

Furthermore, since the airflow guide cover 53 is arranged on the boss portion 45 of the axial flow type fan 41, the air flow becomes smooth, the noise of the axial flow type fan 41 is reduced, and the axial flow type fan 41 is also reduced. The efficiency of can be improved. The fan filter unit is not limited to the one shown in the figure, and may be any unit as long as it is a combination of a fan and a high-performance filter.

FIG. 5 shows a modification of the tunnel type clean room shown in FIG. In the present embodiment, the high performance filter unit 24 and the filter duct 80 also include the fan 8
3, 84 are provided.

This embodiment can also achieve the same effects as the above-mentioned embodiment. FIG. 6 shows an embodiment of a tunnel type clean room according to claim 2. The fan filter unit 30 is lowered to the vicinity of the boundary area C of the filter duct 80. As shown in FIG. 7, the distance L ₁ between the fan filter unit 30 and the production machine 29 is set to 1
050 mm and the distance L ₂ between the fan filter unit 30 and the production machine 29 is set to 255 as shown in FIG.
Experiments were carried out on the vortex area above the production apparatus 29 and the dust discharge capacity when the distance was set to 0 mm.

Dust particle diameter 0.05 μm, 100,000 pieces
The dust decay time (time for the dust concentration to drop to 30%) was measured until / min reached 30,000 particles / min. In the case of FIG. 7, it was 6.31 seconds, and in the case of FIG. 8, it was 9.96 seconds. As described above, it was found that the purifying ability is higher when the fan filter unit 30 is closer to the production machine 29.

This is because by providing the fan filter unit 30 in the vicinity of the production device 29, the pressure loss from the ceiling surface is reduced and the pressure field in the vortex region X rises. From the result of the three-dimensional numerical analysis (simulation), the area of high dust concentration is reduced. This is also because the pressure field in the vortex region x rises. The present embodiment has an effect that the dust decay time can be shortened in addition to the effects of the above-described embodiment.

FIG. 9 shows a modification of the tunnel type clean room shown in FIG. In the present embodiment, the high performance filter unit 24 and the filter duct 80 also include the fan 8
5,86 are provided. This embodiment can also achieve the same effect as the above-mentioned embodiment. In addition, in each of the above-described embodiments, the main part of the tunnel type clean room has been described, but the overall configuration is, for example, the clean tunnel as shown in FIG. 1 of JP-A-61-282742. It has the same form as.

Further, the fan filter unit 30 may be fixed at a predetermined position as in the above-described embodiments, or may be fixed at a predetermined position according to the purpose through an arbitrary lifting device. May be used (claim 3).

[0044]

As described above, in the tunnel type clean room according to claims 1 to 6, as in the conventional tunnel type clean room, a damper is provided in the boundary region to adjust the flow velocity with the low speed region. No operation is required.

Further, since the switching device by the damper is not required, the device becomes simple. Further, since the fan filter unit is provided in a position close to the production device, the dust decay time is shortened, that is, the region of high dust concentration in the vortex region generated in the production device is reduced, and the purification capacity is increased. .

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a tunnel type clean room according to claims 1, 4 to 6.

FIG. 2 is an explanatory diagram showing a flow of clean air in the tunnel type clean room of FIG.

FIG. 3 is a sectional view showing a fan filter unit used in the tunnel type clean room of FIG.

4 is a cross-sectional view of FIG.

FIG. 5 is an explanatory view showing another embodiment of the tunnel type clean room according to claims 1, 4 to 6.

FIG. 6 is an explanatory diagram showing an embodiment of a tunnel type clean room according to claim 2;

FIG. 7 is an explanatory view of the operation of the tunnel type clean room of FIG.

FIG. 8 is an explanatory view of the operation of the tunnel type clean room of FIG.

FIG. 9 is an explanatory view showing another embodiment of the tunnel type clean room according to claim 2;

FIG. 10 is an explanatory view showing a conventional tunnel type clean room.

FIG. 11 is an explanatory view showing a conventional tunnel type clean room.

[Explanation of symbols]

 21 tunnel type clean room 22 hanging wall 23 ceiling 24 high performance filter unit 25 floor 26 ceiling space 27 under floor space 28 air conditioner 29 production machine 30 fan filter unit 31 unit body 35 high performance filter 41 axial flow fan 80 arc section Filter duct 81,82 Outlet A High speed basin B Low speed basin C Border area

Claims (6)

[Claims] 1. A hanging wall divides a high-speed basin requiring high cleanliness from a low-speed basin, a high-speed basin is provided with a fan filter unit, and a low-speed basin is provided with a filter duct having an arc-shaped cross section. A tunnel type clean room. 2. The tunnel-type clean room according to claim 1, wherein the fan filter unit provided in the high-speed basin is located at a height substantially equal to the lower end height of the hanging wall. 3. The fan filter unit provided in the high-speed basin is vertically movable.
The tunnel-type clean room described. 4. The tunnel-type fan filter unit according to claim 1, wherein the fan filter unit provided in the high-speed basin comprises an axial-flow type fan or a centrifugal fan and a filter. Clean room. 5. The blowing speed at the boundary between the high-speed basin and the low-speed basin below the hanging wall is substantially the same as the high-speed basin, according to any one of claims 1 to 4. The tunnel-type clean room described. 6. The filter duct having an arcuate cross section provided in the low speed basin has a blowing speed of an area portion adjacent to the high speed area of the working area that becomes lower as the distance from the high speed area increases. The tunnel-type clean room according to claim 5.