JPH074495B2 - Filter attachment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a clean air device for filtering air with a high-performance air filter and supplying clean air to a clean room, for noise attenuation and uniform air flow.
The present invention relates to a filter attachment used by being laminated on a high performance air filter on the upstream side of the high performance air filter.

[0002]

2. Description of the Related Art In a clean air device for a clean room of a laminar flow type or a unidirectional air flow type, a large amount of clean air is sent at a uniform wind speed of about 0.1 to 0.5 m / sec or more on the downstream side of the filter. Therefore, since a large blower is used, there is a problem that noise generated by the blower or the like is large on the upstream side of the filter. In particular, in recent years, filters have been made thinner in order to reduce the space occupied by the filters in the ceiling and to facilitate work such as installation and replacement due to weight reduction. It reduces the sound insulation effect and raises the level of noise heard in a clean room.

Further, in the above-described clean air apparatus, since the wind velocity of the air horizontally pumped from the wall side toward the space above the filter laid on the ceiling surface is high, it is affected by dynamic pressure. The amount of air passing through the filter is likely to be non-uniform, so that the wind velocity on the downstream side of the filter is likely to be uneven. The method of installing a damper on the filter in order to make the amount of permeated air uniform is impractical because it is difficult to design and adjust in a clean air device in which the ventilation resistance of the filter is large and variable.

[0004]

Therefore, in view of the above points, the present invention has an object to improve quietness in a clean room and to make uniform the wind speed of clean air blown into the clean room. To do.

[0005]

The filter attachment of the present invention comprises a thick plate-like or mat-like sound absorbing material having good air permeability in the thickness direction and a ventilation resistant net disposed above and below the sound absorbing material. did.

[0006]

This filter attachment is used by disposing it on a high performance air filter of a clean air device so as to cover the entire filter.

The filter attachment may be simply mounted on the filter if there is no fear of moving at wind speed, but it may be fixed or locked on the filter by a simple means.

This filter attachment arranged on the air filter suppresses the wind speed by increasing the ventilation resistance of the ventilation resistance net in a region where the wind speed is higher, so the dynamic pressure of the air sent from the blower becomes the filter permeation air volume. Minimize the effect on the air flow and uniformize the wind speed of the clean air flowing into the clean room. Further, the sound absorbing material layer absorbs the noise of the blower, and significantly reduces the noise level.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the embodiment of the present invention will be described with reference to the drawings.

The filter attachment 2 of the present invention shown in combination with the filter 1 in FIG.
It is provided in a state of being laminated with the filter 1 on the upstream side of the air flow passing through. The filter attachment 2 has the same plane shape as that of the filter 1 and has a frame 4 having a support floor 3 in a lattice shape, and a ventilation-resistant net 5 made of synthetic fiber, a thick plate-shaped or mat-shaped sound absorbing material 6, Also, the same net 7 as the net 5 is housed in a stack, and they are fixed by a fixing auxiliary frame 8 so that they are not from the frame 4. The sound absorbing material 6 is a honeycomb structure in the example shown in FIG. 1, has a through hole 9 having a hexagonal cross section, and is arranged so that air flows through the through hole 9 toward the filter 1. .

An example of the thick plate sound absorbing material is a so-called honeycomb structure plate made of paper or other sheet material,
The through holes are arranged in the thickness direction and used. The honeycomb structure has various through-hole shapes such as a hexagonal shape, a square shape, and a sinusoidal shape, but any shape may be used. Since a large mechanical load is not applied to this sound absorbing material, it is also possible to use a plate having a porous structure similar to a honeycomb structure, which is not a structure as rigid as a honeycomb structure.

As another example of the sound absorbing material 6, as shown in FIG.
There are a plate-like body that is bent in a straight line or a curved line and is arranged vertically or inclined in the vertical direction, and a plate in which small holes are punched is horizontally arranged in multiple stages.

As the matte sound absorbing material, any material made of glass fiber, rock wool, metal fiber, various organic synthetic fibers and the like can be used.

These sound-absorbing materials 6 depend on the material and thickness thereof, the shape and cross-sectional area of the through holes in the honeycomb structure plate, and the high density in the mat-like sound-absorbing material.
Different sound absorption characteristics. That is, the frequency with a good sound absorption rate is determined. Therefore, if the noise frequency of the noise source can be analyzed and the sound absorbing material 6 effective for the frequency band to be lowered can be selected, the noise reduction effect is further enhanced. On the other hand, since the frequency characteristics of the noise generated by the clean air device are always different depending on the device, it is desirable to select the sound absorbing material that can obtain the best sound absorbing effect based on the test results for each device used.

As the ventilation resistant nets 5 and 7, fine nets made of fine metal wires or filamentary synthetic fibers are used. Generally, a mesh having a mesh size of about 50 to 100 mesh is suitable. A mesh having a mesh smaller than this has too little ventilation resistance and cannot be expected to have a dynamic pressure relaxation effect described later. Further, a mesh with finer mesh than necessary is not suitable because it only increases the pressure loss. The stitches are 50 to 10
There are two cases in which two sheets of 0 mesh are used for rectification and two cases of finer 100 to 250 meshes are used.

The ventilation resistant nets 5 and 7 and the sound absorbing material 6 are provided with a slight gap. By doing so, the airflow that has passed through the mesh is further rectified before and after flowing into the sound absorbing material 6 having the honeycomb structure.

The frame 4 has plate-like locking metal fittings 1 at four points around the frame.
0 is fixed, and when the filter attachment 2 is placed on the filter 1, the locking metal fitting 10 is attached to the outer periphery of the filter 1.
Are fitted so that both can be fixed.

This filter attachment 2 is shown in FIG.
As shown in Fig. 1, all the filters 1 are placed on the filter unit 1 in the normal clean air device 11.
Use it by covering it. At this time, if each filter attachment 2 is placed right above the filter 1,
The locking metal fitting 10 is tightly engaged with the frame 12 of the filter 1 to be in the state shown in FIG. 1, so that the positional displacement is not easily caused.

When the blower 13 is operated in the above device, the air blown into the upper space 14 of the filter 1 is blown by the blower 13 so that the net 7, the sound absorbing material 6,
It passes through the mesh 5 and the filter 1 in this order and is fluidized in the working space 15.

At that time, a part of the air flow blown from the right side to the left side in FIG.
6, the turbulence is generated and a part of the turbulence naturally flows downward. If there is no filter attachment 2,
The filter closer to the left wall 16 is more strongly affected by the dynamic pressure of the downward turbulence, and the amount of filtered air increases, but in the case of this device equipped with the filter attachment 2, the mesh 5 having a large ventilation resistance is provided on the filter 1. Therefore, the dynamic pressure does not directly act on the filter, and the amount of filtered air becomes uniform regardless of the position of the filter. As a result, clean air flows in the working space 15 in a laminar flow state with a uniform wind speed.

Further, since the sound absorbing material 6 absorbs the noise of the blower 13, the noise passing through the filter 1 is significantly reduced, and the quietness in the working space 15 is improved.

[0021]

As described above, according to the filter attachment of the present invention, since the ventilation resistant nets are integrally laminated above and below the sound absorbing material of the honeycomb structure having good air permeability in the thickness direction, the clean air flow in the clean air device is prevented. It is possible to make the work uniform and at the same time improve the quietness of the work space.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a state in which a filter attachment of the present invention is combined with a filter.

FIG. 2 is a schematic front view showing a state in which the filter attachment of the present invention is applied to a vertical laminar flow type clean room.

3A and 3B show another embodiment of the sound absorbing material of the filter attachment, where A is a plan view and B is a longitudinal sectional view.

[Explanation of symbols]

 1 Filter 2 Filter Attachment 4 Frame 5,7 Net 6 Sound Absorbing Material 9 Sound Absorbing Material Through Hole

Claims (1)

[Claims] 1. A filter attachment comprising a sound-absorbing material having good air permeability in the thickness direction, and air-permeable meshes integrally laminated on the top and bottom of the sound absorbing material.