JP3005521U - Clean air blowing device - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the air frictional resistance in the clean air blowing device to obtain a desired blowing air velocity. [Structure] Below a filter box 1 having a supply port 5 and a built-in HEPA filter 3, a filter box 1 is provided.
A blowout chamber 2 having a larger flat area than that of the blowout chamber 2 is formed, and a porous straightening plate 7 having an area smaller than that of the blowing chamber 2 is attached below the HEPA filter 3 to form an air passage around the straightening plate. In addition to the above, the perforated panel 8 is attached to the blowout port 9 below the blowout chamber 2 to reduce air friction resistance and generated noise.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a clean air supply device for a clean room or a biological clean room, and is for partially maintaining a necessary range in a clean area in order to prevent infection in an operating room or a hospital room of a hospital, for example.

[0002]

[Prior art]

 In a conventional clean room or biological clean room, a HEPA filter is attached to the entire surface of the air outlet to maintain cleanliness, or a complicated bottom surface of the HEPA filter 3 is installed as shown in Fig. 3 to secure a required clean area. The blowout area is expanded by incorporating the flow regulating member 12 for diffusion so that the blown air is diffused and is blown out uniformly from the blowout port 9.

However, in the former case, a HEPA filter having the same area as that of the air outlet is required, and in the latter case, the frictional resistance of the air by the rectifying member 11 increases, so that it is difficult to increase the blowing air velocity.

[0004]

[Problems to be solved by the device]

 In other words, in order to maintain the required cleanliness for a specified clean area, it is necessary to have a blowing area that is at least as large as the clean area, and it is desirable to supply clean air at a uniform wind speed. Corresponding to this, the area of the HEPA filter when the HEPA filter is attached to the blowing surface like the former and the standard blowing air speed is set to 0.35 m / sec, for example, is the standard processing air volume of the HEPA filter. This is more than twice the time.

On the other hand, when the HEPA filter is set with a standard processing air volume and the blowout air velocity is set to about 0.35 m / sec, the HEPA filter 6 is installed on the outlet side for the purpose of ensuring a uniform blowout air velocity as in the latter case. When the complicated rectifying member 11 was incorporated, the air frictional resistance due to the rectifying member 11 increased, and the blowing air velocity did not exceed 0.2 m / sec. Further, there is a problem that the generated noise is increased and the price is increased due to the attachment of the rectifying member 11.

The present invention has been made in view of the above points, and simplifies the rectifying member to reduce the air friction resistance, and at the standard processing air volume of the HEPA filter, the blowing air velocity of at least 0.35 m / sec can be obtained. The purpose is to provide an inexpensive device that can be used.

[0007]

[Means for Solving the Problems]

 According to the present invention, a blow-out chamber having a flat area larger than that of a filter box is installed below a filter box having a built-in HEPA filter, and a perforated panel attached to a blow-out port in the blow-out chamber is provided below the blow-out chamber below the HEPA filter. In other words, a porous straightening vane with a small flat area was arranged to form a passage around the straightening vane, and its operation will be described below.

[0008]

[Action]

 The air sent from the supply port into the filter box passes through the HEPA filter stored in the filter box to be cleaned and sent out from the outlet below the filter box, but between the filter box and the outlet. Is provided with a blowing chamber, and the air that has passed through the filter box is diffused and rectified in the blowing chamber by a porous rectifying plate provided below the HEPA filter.

This rectifying plate rectifies the air from the HEPA filter by passing it through a large number of holes provided in the rectifying plate, and also allows a part of the air hitting the rectifying plate to flow around it. An air flow with a uniform velocity distribution can be sent to the air outlet. In other words, if there is no baffle plate below the HEPA filter, the air from the HEPA filter goes straight and hardly diffuses. Therefore, it is not possible to obtain an air flow with a uniform velocity distribution, but some air flow below the HEPA filter. If a porous rectifying plate with ventilation resistance is attached, the air can be diffused to some extent.

However, it is not enough to simply provide a straightening vane. For example, if a straightening vane is attached to the entire surface of the blowout chamber to suppress and diffuse the air flow, a straightening vane with a small ventilation resistance and a large opening ratio is obtained. If a plate is used, a large amount of air will flow through the central part and will not reach the peripheral part sufficiently. Conversely, if the aperture ratio is too small, the ventilation resistance will increase and the amount of air will decrease, making it impossible to obtain the desired blowing air velocity. That is, if a straightening vane with a small air flow resistance is used, a uniform air flow cannot be obtained over the whole, and if the air flow resistance increases, a desired blowing air speed cannot be obtained.

From this point of view, it is not applicable to a porous straightening plate having a uniform opening ratio over the entire surface, and although the central portion has a certain amount of ventilation resistance, the ventilation resistance gradually decreases as it becomes the peripheral portion. It is desirable that the aperture ratio be changed so that However, such a rectifying plate has another problem that the manufacturing cost is high.

On the other hand, in the present invention, a part of the air from the HEPA filter does not pass through the straightening vanes and also flows from the passages provided around the straightening vanes, so that a substantially uniform velocity distribution is obtained. Can be an air stream. In other words, a part of the air from the HEPA filter is passed through the straightening vanes to be diffused and straightened, and the rest is passed through the passage around the straightening vanes that have no air flow resistance. The amount of air flowing through can be made almost equal. In this way, the air that has passed through the straightening vane and is directed toward the blowing surface passes through the perforated panel provided at the blowing outlet, and is uniformly rectified and supplied as clean air in a laminar flow state into the clean room.

[0013]

[Effect of device]

 According to the present invention, the air friction resistance in the blowout chamber can be greatly reduced by a simple rectifying mechanism in which a porous rectifying plate of an appropriate size is attached below the HEPA filter with an appropriate interval. . As a result, the area of the air outlet can be reduced if the air outlet and the air velocity are the same. For example, when the same HEPA filter is used, a blowing air velocity of about 0.35 m / sec can be realized with a filter area of about 1/2 of the conventional size.

[0014]

【Example】

 Next, an embodiment of the present invention will be described with reference to FIGS. This apparatus comprises a filter box 1 containing a HEPA filter 3 and a blowout chamber 2 connected to the lower part of the filter box 1 to rectify and blow clean air that has passed through the HEPA filter 3 into a clean room. The inside of the filter box 1 is partitioned by a partition plate 6, and a supply port 5 is provided as a chamber 4 on the upper side of the partition plate 6 and a supply duct from an air supply source (not shown) is connected. Further, the HEPA filter 3 is arranged under the partition plate 6, and is fixed to the partition plate 6 in an airtight manner by a mounting bracket 10.

The blow-out chamber 2 has a larger plane area than the filter box 1. The blow-out chamber 2 is provided with a blow-out port 9 below, and the blow-out chamber 2 is provided with an appropriate blow-down chamber below the HEPA filter 3. Porous straightening vanes 7 are arranged at intervals. The flow straightening plate 7 has a smaller plane area than the blowout chamber 2, and a passage 11 is formed around the flow straightening plate 7 with the wall surface of the blowout chamber 2. The current plate 7 is held by a support member (not shown) attached to the wall surface of the blowout chamber 2.

Further, in this embodiment, the straightening vanes 7 are arranged so as to be aligned with the end side of the HEPA filter 3 on the side remote from the supply port 5, and the passage 11a on the side closer to the supply port 5 than the passage 11b on the far side. Is also wide. The reason why the straightening vanes 7 are arranged so as to be displaced from the center of the HEPA filter 3 is that the air passing through the HEPA filter is diffused into the blowing chamber 2 having an area larger than that of the HEPA filter to make the blowing air amount uniform. is there. That is, the air that has passed through the HEPA filter is more likely to flow on the far side than on the side closer to the supply port 5, so that the velocity distribution of the blown air is prevented from becoming non-uniform. By narrowing the passage 11b to a side farther away from the supply port 5 to narrow the passage 11a and widening the passage 11a, the air amount in the passage 11b can be suppressed, and the air amount in the passage 11a can be increased to increase the speed of the air blown to the blowing surface. The distribution can be made uniform to some extent. In this way, the air that has passed through the straightening vanes 7 and the air that does not pass through the straightening vanes 7 but flows through the passages 11 can be sent out toward the blowing surface as an air flow having a substantially uniform velocity distribution at the blowout ports 9. Further, another perforated panel 8 is attached to the outlet 9 so that the blown air is further rectified to form a laminar flow state.

By the way, regarding the aperture ratio of the straightening vanes 7 and the perforated panel 8, the size and the mounting position of the straightening vanes 7, the size of the passages 11, etc., influence the ventilation resistance. It is necessary to select the one with an appropriate opening ratio so as not to lose the blowout air velocity and to consider the mounting position of the current plate 7. Further, the HEPA filter 3 can be easily replaced by removing the perforated panel 8 and the rectifying plate 7 from the indoor side and then removing the mounting bracket 10.

With the above configuration, the air introduced into the filter box 1 from the supply port 5 is purified by passing through the HEPA filter 3. Next, the clean air that has passed through the HEPA filter 3 is diffused and rectified by the rectifying plate 7 in the blowout chamber 2, and is further rectified to a uniform wind speed by the blowout panel 8 attached to the blowout port 9 so that the cleanroom is clean. Supplied within.

[0019]

[Experimental example]

In the above device, the dimensions of 610 mm × 915 mm and the thickness of 150 mm were 0. A HEPA filter 3 with a collection rate of 3 μm of 99.97%, a rectifying plate 7 with a blowing surface dimension of 900 mm × 680 mm and an aperture rate of 26%, and a porous panel 8 with a dimension of 900 mm × 1500 mm and an aperture rate of 16% 8 Was attached and operated at an air flow rate of 1680 m ³ / h and a blowing air velocity of 0.35 m / sec, the air friction resistance in the blowing chamber 2 was 2 to 3 mmAq. This is a conventional device. Compared with the air friction resistance of 6 mmAq or more in the blowout chamber 2 when the same HEPA filter 3 and multi-hole panel 8 were attached and the air flow rate was 1000 m ³ / h and the air friction resistance was 6 mmAq or more. Is less than half. In addition, the noise generated was also significantly reduced.

[0020]

[Another embodiment]

 The punch plate of the straightening plate 7 and the perforated panel 8 may be made of a steel plate, a metal such as stainless steel or aluminum, or a net or a perforated plate made of a synthetic resin, or a filter-like one. In addition to the circular shape, the opening may be an elliptical shape, a square shape, or an elongated slit shape.

[Brief description of drawings]

FIG. 1 is a plan view of the present embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 shows a conventional example.

[0021]

[Explanation of symbols]

 1 Filter Box 2 Blow Chamber 3 HEPA Filter 5 Supply Port 6 Partition Plate 7 Rectifier Plate 8 Blowout Panel 9 Blowout Port 10 Fixture 11 Passage

Claims (1)

[Scope of utility model registration request] 1. A blow-out chamber 2 having a plane area larger than that of the filter box 1 is attached below a filter box 1 having an air supply port 5 and a built-in HEPA filter 3 to integrate the blow-out chamber 2 with the blow-out chamber 2. A perforated panel 8 is attached to the entire surface of 9, and a perforated straightening plate 7 having a smaller plane area than that of the blowing chamber 2 is disposed between the HEPA filter 3 and the perforated panel 8 with an appropriate interval therebetween. A clean air blowing device characterized in that a passage 11 is formed around the straightening vane 7.