JPH06142430A - Method and device for purifying air - Google Patents

Abstract

PURPOSE:To provide a method and device for purifying air where fine particles floating in the air are effectively captured to get the specified degree of cleanliness in a short time even when using a filter of ordinary performance. CONSTITUTION:Fine particles of water are generated by a mist generator 150 and grown in size by combining with contaminated floating particles in air. The particles which have increased in size are captured by a filter 130. Therefore, fine particles of water and fine contaminating floating particles in air are combined to grow into particles of large size which are captured and filtered out by the filter 130.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air cleaning method and a cleaning apparatus for purifying air by capturing fine particles such as dust and dirt floating in the air.

[0002]

2. Description of the Related Art In the atmosphere, exhaust gas, flue gas, sulfurous acid gas and carbon dioxide gas, dust, mites, pollen and many other dusts,
Bacteria are floating and these substances pollute the atmosphere. However, a clean air environment is required in various fields such as the electronic industry, medical care, and food, and therefore clean rooms are used.

As a means for cleaning the air in a clean room, a method of capturing suspended particles in the air by a blower and a filter has been conventionally used. That is,
In this method, the air in the clean room is circulated by a blower, a filter is provided in the middle of this circulation path, and when the air passes through this filter, the contaminant floating particles contained in the air are captured by the filter, This is a method of supplying filtered air to a clean room.

In order to enhance the purification effect by such a filtering method, the mesh of the filter may be made thin, but if this is done, the passage resistance of the air will increase and the pressure loss will increase. Therefore, measures such as equipping a high-pressure blower with more capacity than necessary and increasing the number of air circulations are necessary. That is, the filtration performance of the mesh is usually evaluated by the capture efficiency of fine particles of 0.3 μm or less, but if the capture efficiency of fine particles of 0.3 μm or less is set to 99% or more, a filter with an extremely fine mesh is used. This is necessary, and in this case, a high pressure blower is used because it causes a large pressure loss, and therefore there is a drawback that the equipment cost becomes high.

[0005]

When a commercially available air cleaner is used in order to reduce the equipment cost, it is difficult to capture fine particles of 0.3 μm or less due to the poor filtration performance of the filter, or the air cleaner is used. There is a drawback that it takes a considerably long time from the start of operation of the purifier until a predetermined degree of cleanliness is obtained.

The present invention has been made in view of the above circumstances, and an object thereof is to enable fine particles to be effectively captured even with a filter having a normal performance, so that a predetermined particle size can be obtained in a short time. An object of the present invention is to provide an air cleaning method and a cleaning device that can obtain cleanliness.

[0007]

In order to achieve the above object, the air cleaning method of the present invention comprises:

[0008] Fine particles of water are generated by a mist generator, the fine particles of water are combined with contaminating suspended particles in the air to grow the suspended particles largely, and the increased particles are captured by a filter. It is characterized by having done. Further, the cleaning device of the present invention,

A mist generating device for generating fine particles of water is provided in a housing having a suction port and a discharge port, a filter is installed at the suction port, and fine particles of water generated by the mist generating device are air-cooled. It is mixed with and supplied to the external space through the outlet, and the floating particles are grown by combining the contaminated suspended particles in this space with the fine particles of water in this space, and the increased particles are added to the filter. It is characterized in that it is adapted to be captured.

[0010]

In any of the air cleaning method and the cleaning apparatus of the present invention, fine particles of water are combined with fine floating particles floating in the air to obtain floating particles of 0.3 μm or less. Even if it exists, it can be grown into large particles of 0.3 μm or more, and these large particles can be captured by a filter and filtered. Therefore, the suspended particles can be effectively captured without making the mesh degree of the filter extremely dense, and a predetermined cleanliness can be obtained in a short time.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the first embodiment shown in FIGS.

In the figure, reference numeral 100 designates a housing, which has a suction port 110 opened on one side and a discharge port 120 provided on the other side. The suction port 110 is provided with a filter 130 that captures polluted suspended particles in the air, and the blowout port 120 is provided with a blower blower 140 for blowing the air inside the housing 100 into an external space, for example, the clean room 200. is set up.

A fine mist generator 150 is accommodated in the housing 100. The fine mist generator 150 of this embodiment employs a device that atomizes the water by a centrifugal force to blow off the water by centrifugal force. The fine mist generator 150 will be described. Reference numeral 1 is a water tank housed in the housing 100.
Has a box shape with an open top, and contains a predetermined amount of water 3. A cylindrical water filter 2 is accommodated in the water tank 1, the lower end of the water filter 2 is detachably attached to the bottom surface of the water tank 1, and the upper end is opened. A base 5, which also serves as a lid, is detachably attached to the upper opening of the water tank 1. An opening 6 is formed in the base 5, and a mounting table 7 is formed on the opening 6.
A motor 8 is attached to the mounting table 7. A space 9 is provided between the mounting table 7 and the base 5, and air is allowed to flow into the water tank 1 through the space 9. The motor shaft 10 of the motor 8 fixed to the mounting table 7 extends downward, and a pair of rotating plates 11 and 12 are connected to the lower end of the motor shaft 10. These rotary plates 11 and 12 have a minute gap 13 of about 0.5 to 1.5 mm secured between them. That is, the pair of rotating plates 11 and 12 includes a plurality of connecting members 14 ...
Are opposed to each other with a predetermined gap 13,
The central portion of the upper rotating plate 11 is fixed to the lower end of the motor shaft 10. Therefore, the pair of rotating plates 11, 1
2 is rotated integrally with the rotation of the motor 8. The rotation speed is, for example, about 3000 rpm.

A suction pipe 15 is connected to the central portion of the rotating plate 12 located on the lower side. The suction pipe 15 is composed of, for example, a pipe having an inner diameter of about 2 to 5 mm, its upper end is connected to the central portion of the lower rotary plate 12, and its opening is exposed to the upper surface of the lower rotary plate 12. At the same time, the lower end is opened to the bottom of the water tank 1. The lower end of the suction pipe 15 is immersed in the water tank 1 surrounded by the water filter 2.

The motor 8 is covered by a motor cover 16 attached to the base 7. This motor cover 16
An air suction fan 17 is attached to the air suction fan 17, and the air suction fan 17 forcibly introduces the air in the housing 100 into the motor cover 16. The air introduced into the motor cover 16 passes through the gap 9 between the mounting table 7 and the base 5 and is guided to the upper part of the water tank 1. The rotating plates 11 and 12 are arranged above the water tank 1, and the rotating plates 11 and 12 are exposed to the air.

Guide plates 18 are provided on the lower surface of the base 7 at a position close to one side from the positions of the rotary plates 11 and 12, and these guide plates 18 form a passage 19 for causing the air flow to meander. is doing.

At the end of the base 7, a steam / water separating cylinder 20 is provided.
Is attached to the inside of the steam / water separation cylinder 20,
A plurality of baffles 21 ... Are attached. Steam separation cylinder 20
Has a lower end opened to the upper part of the water tank 1, and a fine mist supply duct 22 is connected to the upper end. The upper end of the fine mist supply duct 22 has the blower blower 140.
Are linked to. The blower blower 140 is the housing 1
The air in 00 is sucked, the fine mist supplied from the fine mist supply duct 22 is mixed with the sucked air, and the mist-mixed air is ejected from the outlet 120 to the external space. The operation of the air cleaning device having such a configuration will be described. When a power switch (not shown) is turned on, the blower blower 140, the air suction fan 17 and the motor 8 are started.

The blower blower 140 sucks in and pressurizes the air in the housing 100, and blows out the pressurized air from the blowout port 12.
Discharge from 0 to the clean room 200. As a result, the air pressure in the housing 100 becomes low, so that the suction port 11
Intake outside air from 0. When the air in the clean room 200 flows into the housing 100 through the suction port 110, the air passes through the filter 130, and at this time, fine particles of dust, such as dust, contained in the air are captured by the filter 130, and the inside of the housing 100 Purified and filtered air is introduced. This purified air is discharged from the outlet 120 to the clean room 200 by the blower 140.
Therefore, the air in the clean room 200 is filtered by being circulated in the air purifier, and the contaminated suspended matter is filtered. By the way, when the air suction fan 17 is operated in the housing 100, the air in the housing 100 is introduced into the motor cover 16, and the introduced air passes through the gap 9 between the mounting table 7 and the base 5 to generate water. Send to the top of tank 1. This air passes through the meandering passage 19 formed between the guide plates 18 at the upper portion of the water tank 1, passes through the air / water separating cylinder 20, and flows out from the outlet 23 of the supply duct 22 to the outside.

In the course of such air flow, the motor 8
The rotation plates 11 and 12 are rotated by the rotation. The rotation of the rotary plates 11 and 12 generates a centrifugal force in the minute gap 13 formed between the rotary plates 11 and 12. This centrifugal force will generate a negative pressure in the center of the gap 13,
The suction pipe 15 has a negative pressure and therefore sucks the water in the water tank 1 into the gap 13. The water introduced into the gap 13 through the suction pipe 15 is scattered around the rotary plates 11 and 12 by the centrifugal force of the rotary plates 11 and 12. The water scattered around by the centrifugal force of the rotating plates 11 and 12 is crushed by this scattering and becomes a droplet, which is atomized. Since this miniaturization is blown off by the centrifugal force of the rotary plates 11 and 12, it is possible to generate mist having an extremely small particle size, for example, 0.3 μm or less. Therefore, a fine mist is generated in the upper space of the water tank 1, and this mist is mixed with the air guided from the opening 6 of the base 5. In this case, large water droplets that are not atomized also occur,
Water droplets with large particles fall into the water tank 1 under the influence of gravity.

A mixture of the fine particle mist and air is
The air passes through a meandering passage 19 formed between the guide plates 18 along the flow of air, and when passing through the meandering passage 19, it collides with the wall of the bent passage, receives the resistance of the wall, and becomes a guide wall 18. Due to a collision or the like, a large mist of relatively large kinetic energy contained in this mixture adheres to the guide wall 18, flows along the wall of the meandering passage 19, and is dropped into the water tank 1. Further, the mixture of mist and air passes through the air / water separation cylinder 20 and collides with the baffle plates 21 ... At this time, water droplets of smaller particles are generated.
1. Therefore, only the mist having a very small particle diameter blows out from the supply duct 22 together with the air, and the blower 14
Sent to 0.

This fine mist is further blown out by a blower 1
It is mixed with the air sucked into 40 and discharged from the outlet 120 into the clean room 200. Clean room 2
In No. 00, pollutant particles are bound to the fine particles of water, such as dust, dust, soot, various gases, and bacteria floating in the air, so that the pollutant suspended particles grow and the particle size increases. Such large contaminated airborne particles are generated by the housing 10.
When it is taken into the housing 100 through the suction port 110 of 0, it is captured by the filter 130.

That is, even fine polluted suspended particles that cannot be normally captured can be captured by using the conventional filter 130 because the particles become large when combined with mist.

Therefore, it is not necessary to use a filter having a particularly fine mesh, and it is not necessary to use a blower having a large blowing capacity. Furthermore, the degree of cleanliness can be increased in a short time, and the cleaning can be performed quickly. Can create an air environment. Experiments conducted by the present inventors in order to confirm the effects of the air cleaners of FIGS. 1 and 2 will be described.

In the apparatus shown in FIG. 1, the filter 130 used in an air purifier manufactured by Mitsubishi Heavy Industries Ltd., which has a capture efficiency of 0.3 μm particles of 64%, is used.
An EPA filter was used. The blower blower 140 has an air flow of 3.0 m ³ / Min and the mist generator 150 installed in the housing 100 is operated at the same time (invention) and the mist generator 150 is not operated (conventional) in the clean room 200. The number of particles was measured. The air suction fan 17 of the mist generator 150 has a blowing amount of 0.5 m ³ / Min is set. In addition, the clean room 200 has a size of 6 tatami mats and a volume of 2
4m ³ After smoking two cigarettes in this room, the number of suspended particles remaining in the room 200 was measured over time.

The measurement results are shown in FIG. Characteristic A in FIG.
_TOTAL and the characteristic B _TOTAL indicate the total number of all the suspended particles, and when the blower 140 and the mist generator 150 are simultaneously operated to capture the suspended particles by the filter 130, as indicated by the characteristic A _TOTAL , It was confirmed that the residual airborne particles in the air could be reduced to 50,000 particles / 0.01 cubic feet or less within one hour, and high cleanliness could be obtained in a short time. On the other hand, in the conventional case where only the blower 140 is operated without operating the mist generator 150 to trap the suspended particles by the filter 130, as shown by the characteristic B _TOTAL , there are 50,000 residual suspended particles. It can be seen that if it is attempted to make it less than /0.01 cubic feet, continuous operation for about 2 hours and 30 minutes is required, and therefore the purification capacity is low.

Further, in FIG. 3, the characteristics A _1.0 and the characteristics B _1.0 are such that the sizes of airborne particles in the air are 1.
The number of remaining particles of 0 μm or more is measured, and the characteristic A _1.0 when the blower 140 and the mist generator 150 are simultaneously operated to trap the suspended particles by the filter 130 and the mist generator 150 are measured. Only the blower blower 140 is operated without operation and the filter 13
It was found that the characteristic B _1.0 in the conventional case in which the suspended particles were captured by 0 was not significantly different in the remaining amount. It is considered that this is because, since the particles are large, no significant difference occurs in the filtering action of the filter 130.

However, in FIG. 3, characteristic A _0.5 and characteristic B _0.5 are the numbers of residual particles in the air having a size of 0.5 μm, respectively, measured, and the blower blower 140 and the mist are generated. The characteristic A _0.5 when the device 150 is operated at the same time to capture the suspended particles by the filter 130 has the characteristic that the filter 13 is operated by operating only the blower 140 without operating the mist generation device 150.
It can be seen that the remaining amount decreases in a short time as compared with the characteristic B _0.5 in the conventional case in which the suspended particles are captured by 0.

Further, in FIG. 3, a characteristic A _0.3 and a characteristic B _0.3 are the numbers of remaining particles in the air having a size of 0.3 μm or less, respectively, measured, and the blower 140 and the mist are measured. The characteristic A _0.3 in the case where the generator 130 is operated at the same time to capture the suspended particles by the filter 130 has the characteristic A _0.3 that the blower 140 alone is operated without operating the mist generator 150 to capture the suspended particles by the filter 130. It can be seen that the remaining amount decreases within an extremely short time, compared with the characteristic B _0.3 in the conventional case.

From the above, it was confirmed that the smaller the particle size of the pollutant floating in the air, the more effective the action of the air purifying device in the present invention, which is the fine particles released into the air. It is presumed that such mist combined with the particles of the pollutants floating in the air to increase the size of the particles of the suspended particles, which facilitated capture by the filter 130.

In FIG. 3, the characteristic A _0.5 and the characteristic B _0.5 , and the characteristic A _0.3 and the characteristic B _0.3 exhibit an ascending slope for a few minutes from the start of the operation, and the number of these particles temporarily increases. This is because the particles attached to the floor, ceiling, and side walls of the room float in the space due to the air flow. In addition, characteristic A _0.5 and characteristic A _0.3
In the case of (1), the emitted fine mist is measured as particles, so that a temporary sharp rise is exhibited. From the above experiments, it can be understood that the method and apparatus of the present invention have excellent air cleaning ability and can create an air environment of high cleanliness in a short time.

When water is split in the air and atomized by the centrifugal force of the rotary plates 11 and 12, negative ions are generated in the nearby air, and the air is negatively ionized by the so-called Leonard effect. That is, a large amount of negative ions are generated in the upper space of the water tank 1.

Such negatively ionized air is blown out together with the mist by the blower 140 to clean room 20.
0 to neutralize static electricity. For this reason, the particles in the room adhering to each other are released by the force of static electricity and are allowed to float freely, so that they are more likely to combine with the mist, the trapping efficiency is further increased, and the cleaning effect is enhanced.

Further, the mist generator 150 of the above embodiment.
In the case of, since the water in the water tank 1 is sucked up through the suction pipe 15 by the action of the centrifugal force of the pair of rotating plates 11 and 12,
No special pump is required for supplying water to the rotating plates 11 and 12. Therefore, the structure is simple and the power consumption is low. Further, the size of the fine particles of water generated by the mist generator 150 is preferably 0.3 μm or less.

That is, the filter generally used has an excellent ability to capture particles having a size of 0.3 μm or more, but has a poor ability to capture particles having a size of 0.3 μm or less. The residual rate of the following suspended particles is large. When it is attempted to combine such small suspended particles with the mist, the size of the mist is similar to that of the fine suspended particles, and it becomes easy to combine with each other. Therefore,
It is desirable that the size of the mist is similar to the size of the remaining floating particles, that is, 0.3 μm or less.

From this point, in the mist generator 150 of the above-described embodiment, the diameter of the rotary plates 11, 12 is 140 mm, the gap 13 between the rotary plates 11, 12 is 1.5 mm, and the rotary plates 11, 12 are rotated. It has been confirmed that when the speed is 2900 rpm, a mist having an average particle size of 0.28 μm is generated, and the number of fine particles of 0.1 to 0.5 μm is 0.
More than 1 million pieces per 01 cubic foot, 0.3μ
It is presumed that the number of fine particles having a size of m or less is considerable.

The present invention is not limited to the above embodiment. In particular, the mist generator 150 is not limited to one that atomizes water by utilizing the rotational centrifugal force of the pair of rotating plates 11 and 12 described above, and a humidifier 50 as shown in FIG. 4 may be used. Since the humidifier 50 may be a commercially available one, detailed description thereof will be omitted, but it may be either a heater type or an ultrasonic type, for example, the water in the cartridge tank 51 is atomized by the mist generating section 52, The structure may be such that this mist is discharged from the discharge port 53. Such a humidifier 5
Even if 0 is used as the mist generator, the same effect as that of the above-mentioned embodiment can be obtained.

Further, as described above, the clean room 2
It is desirable that the size of the mist discharged to 00 is 0.3 μm or less, but if the mist generated by the mist generators 150 and 50 includes a large mist of 0.3 μm or more, a clean room There is a concern that the inside of 200 will become humid, and in order to prevent this, the housing 1
The blowout port 120 of 00 may be provided with a mist filter for capturing a large mist.

[0038]

As described above, according to the present invention, fine particles of water and fine particles of contaminated air suspended in the air are combined in any of the air cleaning method and the cleaning device. Since the large particles are grown and captured by the filter, fine contaminating suspended particles can be filtered even by using a filter which has been widely used conventionally. Therefore, the suspended particles can be effectively captured without making the mesh degree of the filter extremely dense, a predetermined clean degree can be obtained in a short time, and a clean air environment can be created.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an air cleaning device showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA in FIG.

FIG. 3 is a characteristic diagram showing a result of an experiment of the same example.

FIG. 4 is a cross-sectional view of an air cleaning device showing another embodiment of the present invention.

[Explanation of symbols]

1 ... Water tank 8 ... Motor 1
1, 12 ... Rotating plate 13 ... Gap 15 ... Suction pipe 21
... Supply duct 100 ... Housing 110 ... Suction port 12
0 ... Blowout port 130 ... Filter 140 ... Blowout blower 150, 50 ... Mist generator

Claims (4)

[Claims] 1. A mist generator is used to generate fine particles of water, and the fine particles of water are combined with airborne contaminant particles to grow the airborne particles and filter the increased particles. A method for cleaning air, characterized in that it is captured at. 2. A fine particle of water generated by the mist generating device, wherein a mist generating device for generating fine particles of water is provided in a housing having a suction port and a discharge port, and a filter is installed at the suction port. Is mixed with air and supplied to the external space from the outlet, and the polluted suspended particles are grown by combining the polluted suspended particles and the fine particles of water in the external space, and the increased particles are applied to the filter. An air purifier characterized in that it is adapted to be captured. 3. The air cleaning apparatus according to claim 2, wherein the fine particles of water generated by the mist generator have an average size of 0.3 μm or less. 4. The mist generating device comprises a pair of rotary plates, which face each other with a predetermined gap therebetween, rotate the rotary plates integrally by a motor, and at the same time, install a suction pipe at the center of one of the rotary plates. The open ends are connected, the lower end of the suction pipe is immersed in water contained in a tank, and a negative pressure is generated in the gap between these rotating plates by centrifugal force. The water of claim 2 is introduced into the gap through the suction pipe, and the water in the gap is dispersed by centrifugal force to be atomized. apparatus.