JPH0230659Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Technical Field of the Invention] The present invention relates to an air cleaning device used for operations such as resist film coating, exposure, and etching, for example, in a semiconductor integrated circuit element production factory. [Technical Background of the Invention] Conventionally, when performing work that is extremely dust-free, such as in the manufacturing process of semiconductor devices, an air cleaning device as shown in FIG. 5, for example, is used. A primary filter 2 and a fan 3 are housed in a first case 4 and provided at the upper rear side of a rectangular frame surrounded by a support column 1. A secondary filter 6 is provided on the bottom of the second case 5 connected to the first case 4, and the air that has passed through the secondary filter 6 is blown downward from the clean air outlet 7 toward the air clean area 8. I'm trying to get it out. And 9 is air purification area 8
The working opening 10a provided in the front of the air cleaning area 8 is a curtain made of transparent vinyl or the like that blocks both sides of the air cleaning area 8 from the outside air. Furthermore, 10b is air cleaning area 8
10c is a workbench, and 10d is a lighting lamp. A sound deadening material 10e such as glass wool covering material is attached to the inner wall of the second case 5 to suppress the generation of noise. [Problems with Background Art] However, this type of device has the disadvantage that outside air tends to flow into the air cleaning area from the working opening, making it impossible to maintain a high degree of cleanliness. [Purpose of the invention] The present invention was made in view of the above circumstances, and with its simple configuration, it is possible to significantly reduce the inflow of outside air from the working opening into the air clean area, and maintain a high level of air cleanliness. The purpose is to provide an air purifying device. [Summary of the invention] The invention is characterized in that a second guide plate is suspended from the tip of the first guide plate that extends obliquely from the upper edge of the working opening into the air cleaning area. . [Embodiment of the invention] Hereinafter, an embodiment of the invention will be described in detail with reference to a side sectional view shown in FIG. 1 and a plan view shown in FIG. 2. A first case 12 is provided at the upper rear side of a rectangular frame surrounded by pillars 11, and a second case 13 is arranged at the upper front side of the frame in connection with this first case 12. . The first case 12 has an opening at the bottom for sucking in return air, and a relatively coarse primary filter 14 is provided in this opening in a replaceable manner.
Then, a fan 15 is provided in the first case 12,
Air is blown out into the second case 13 from the air supply port 16. A duct 17 is provided in the second case 13 to direct the air blown from the air supply port 16 downward, and a porous diffuser 18 is provided at the outlet of the duct 17 to rectify the air flow. The airflow that has passed through this passes through a high-performance secondary filter 19 that is removably attached to the bottom of the second case 13 and has an efficiency of 99.97% or more based on the DOP method, for example.
It blows out downward into the air clean area 20. Note that the lower surface of the secondary filter 19 of the second case 13 has a structure in which the purified air flows downward in the air purification area 20 in a laminar flow state or a state close to it.
A downwardly opened clean air outlet 21 made of a perforated plate or the like is provided. A working opening 22 is provided on the front side of the air cleaning area 20. A first guide plate 23 is arranged diagonally from the upper edge of this working opening 22 toward the air cleaning area 20 and whose inclination angle is variable.
Extend. Furthermore, a second guide plate 24 is provided to hang down from the tip of the first guide plate 23. Note that the first and second guide plates 23 and 24 are made of, for example, non-static acrylic plates in order to prevent dust from adhering to the guide plates and from re-dusting as much as possible. The reference numeral 25 indicates a work table disposed within the air purification area 20, and the reference numeral 26 indicates an illumination light. Both sides of the air-cleaning area 20 are shielded from the surrounding air by removable curtains 27 made of transparent vinyl or the like.
7 is removed so that the sides of a plurality of air purifiers can be connected to each other and used. Further, on the rear side of the air cleaning area 20, a hard plate 28 such as a steel plate or a plastic plate blocks the clean air from the surrounding air. In addition,
The clean air that has passed through the air clean area 20 returns to the primary filter 14 through a gap provided at its lower end. With such a configuration, ambient air is sucked into the first case 12 where it is filtered by the primary filter 14. and the second case 13 by Juan 15
It is blown out inside. In the second case 13, the airflow is directed downward by the duct 17, and the airflow is rectified by the porous diffuser 18 disposed at the outlet of the duct 17, which is arranged substantially perpendicular to the flow path of the airflow. Distributed supply to the secondary filter. The highly purified air that has passed through the secondary filter 19 is then blown out from the upper part of the air clean area 20 downward through the clean air outlet 21. At the working opening 22, the airflow is directed slightly inward by the first guide plate 23, creating an air curtain effect. However, if only the first guide plate 23 is used, the air flow whose direction is adjusted here will go inward of the air cleaning area 20, so the cleaned area will be reduced.
In addition, turbulence tends to occur here, which poses the problem of attracting and dispersing contaminated air from outside. On the other hand, in the above embodiment, the first guide plate 2
A second guide plate 24 is provided hanging down from the tip of 3. Therefore, the airflow whose flow direction has been adjusted by the first guide plate 23 can be caused to flow downward again in the vertical direction along the second guide plate 24 due to the attached flow (Coanda effect). Therefore, an air curtain can be formed in the working opening 22 without constricting the clean area, and turbulence in the airflow can be significantly reduced. Next, the air flow distribution and cleanliness of the air cleaning device having the first and second guide plates shown in the above example and the device from which the second guide plate was removed were compared. Both air purifiers are 1300m/m wide and deep.
Clean air is blown out at an air volume of 40 m ³ /min by a 0.4 kW Shirotsko fan to an air clean area of 970 m/m and a height of 1400 m/m from the floor to the clean air outlet 21. And the working opening is
Width 1300m/m, height from the floor to the second guide plate 2
The size is up to the bottom of 4. Note that the wind speed measurement point is parallel to the work opening and located away from the opening as shown in the side view in Figure 3.
150 m/m, 350 m/m from the left end of the opening, as shown in the front view in Figure 4, on the first measuring surface 120 m/m inside, the second measuring surface 170 m/m inside,
550m/m, 750m/m, 950m/m and
1150m/m measurement lines a, b, c, d, e,
900m/m, 1000m/m from the floor (FL) at f
m, 1100m/m, 1200m/m height points.
The measurement results are shown in Tables 1 to 4 below.

【table】

【table】

【table】

【table】

[Table] As is clear from the comparison of Table 1 and Table 3 from this measurement result, the one with the first and second guide plates is better than the one without the second guide plate. There is little decrease in wind speed even below the clean area.
The average wind speed is also high. Therefore, with the first and second guide plates, it is possible to form a good air curtain on the opening surface, the wind speed is almost uniform, there is very little turbulence, and therefore there is no contamination from the outside. It is also difficult to attract. Similarly, comparing the results of Table 2 and Table 4,
Although the turbulence of the wind speed is approximately the same, the device of the above embodiment having the first and second guide plates is about 0.02 m/s faster in terms of average wind speed, and the air curtain effect is superior. It shows. The next cleanliness measurement point is from the left edge of the opening.
At the center of the width direction of 650m/m, as shown in Figure 3, point A is 1200m/m from the floor on the first measurement surface, point B is 1000m/m from the floor, and similarly on the second measurement surface. Point C is 1200m/m from the floor, and 1000m/m from the floor.
Measurements were made at four points including point D. The measurement results are shown in Tables 5 and 6 below. The surrounding environment during the measurement was as clean as a normal living room.

【table】

[Effect of idea]

As described above, according to the present invention, it is possible to provide an air purifying device that can keep an air cleaning area in a highly purified state with a simple configuration.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing an embodiment of the present invention, Fig. 2 is a plan view of the above embodiment, and Figs. 3 and 4 are diagrams illustrating the measurement positions at which the performance of the air purifying device was measured. FIG. 3 is a side view, FIG. 4 is a front view, and FIG. 5 is a side sectional view showing an example of a conventional air cleaning device. 14...Primary filter, 15...Fan, 19
...Secondary filter, 20...Air cleaning area, 22...
...Working opening, 23...First guide plate, 24...
...Second guide plate.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A defined air-cleaning area, a clean air outlet provided above the air-cleaning area and blowing clean air downward, and one side of the air-cleaning area. a first guide plate that extends diagonally from the upper edge of the work opening into the air-cleaning area; and a second guide plate that hangs down from the tip of the first guide plate. An air purifying device comprising: (2) Utility Model Registration The air purifying device as set forth in claim 1, characterized in that the first guide plate is provided with an adjustable inclination angle. (3) Utility model registration Claim 1 In the air purifying device according to claim 1, the first and second guide plates are non-electrostatic type acrylic plates.