JP2000005629A - Air cleaning apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized and easy-to-handle air cleaner and a method for efficiently cleaning air. SOLUTION: An electrostatic air cleaning apparatus for removing a fine substance in air comprises an apparatus including a filter part 2, a means 1 permitting air to be cleaned to pass so as to traverse the filter part and a charging part 3 and the filter part is a positively chargeable nonwoven fabric. This apparatus is used to collect negatively charged fine substances contained air by the positively charged filter to purify air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for removing fine substances such as pollen, dust, microorganisms and the like floating in gas, especially in air.

[0002]

2. Description of the Related Art In a civilized society in recent years, various fine substances have been discharged into the air with various industrial activities.
Their types and quantities are ever increasing. The discharged fine substances contain many substances harmful to the human body, and many of them cause respiratory diseases or cancer. In the atmosphere, allergens such as cedar pollen, microorganisms, and the like also float or exist as fine substances, and these may have a bad influence on the human body.

[0003] On the other hand, at the production site of precision electronic devices or parts or foods, or in the fermentation process of the fermentation industry, the amount of substances suspended in the air is extremely reduced or substantially reduced in order to prevent contamination of products. It may be necessary to completely remove it. Similarly, in the operating room or hospital room of a hospital, the amount of fine substances contained in the air must be strictly controlled in order to prevent infection.

[0004] As described above, the necessity of reducing fine substances floating or existing in the atmosphere, including fine substances harmful to the human body, has been increasing in recent years. Therefore, for example, removal of fine substances by a method of passing pressurized air through a microporous membrane using a sterilizing filter or removal of fine substances using a high-pressure electrostatic dust remover (Cottrell filter) is performed. The former method is employed in the fields of fermentation industry, electronics industry, and the like, and the latter method is employed in the field of electronics industry, hospital operating rooms, and the like.

[0005]

However, the removal of fine substances by the above two methods requires large-scale equipment and a large amount of running energy. Can not be adopted.

[0006] Purification of air by removing harmful fine substances can be performed in the space where ordinary people including infants and the elderly with low resistance live, and in operating rooms and hospital rooms of small and medium-sized hospitals. Is also necessary. Therefore, an air purifying device that can be easily handled and has small running energy has been desired. The present inventor has conducted intensive studies to obtain an air purification device that satisfies such demands.
The present invention has been completed.

[0007]

In the air purifying apparatus and method of the present invention, the surface of fine substances (including microorganisms; the same applies hereinafter) floating or existing in the air is often negatively charged. And an apparatus and a method for efficiently capturing fine substances with a filter portion positively charged electrostatically by utilizing the method. That is, the air purification device of the present invention is a device including a filter portion, a unit for passing air to be purified across the filter portion, and a charging portion, wherein the filter portion is a non-woven fabric capable of adding positive electrostatic charge. An electrostatic air purification device characterized by the following.

Here, the filter means means for trapping fine substances contained in the air, and means for passing air to be purified across the filter means means for filtering fine substances contained in the air. Means means for allowing the air to be purified to pass through the filter section so as to be captured by the filter section, and the charged section means means or a device for positively charging the non-woven fabric. Further, the nonwoven fabric capable of positive electrostatic charge refers to a nonwoven fabric capable of electrostatically charging a positive charge.

The electrostatic air purifying method of the present invention is a method of purifying air using the electrostatic air purifying apparatus. The non-woven fabric as a filter is positively charged by a charging unit, and the positive air is charged. It is characterized in that air to be purified is passed across the electrostatically charged filter portion, and the filter portion captures negatively charged fine substances to purify the air.

[0010]

FIG. 1 shows an example of an air purifying apparatus according to the present invention. According to the apparatus shown in FIG. 1, the air containing the fine substance passes through the air to be purified across the filter section (hereinafter, may be referred to as air passing means).
The light passes through the filter section (2) by the action of (1). At this time, the fine substance in the air that is negatively charged is electrically connected to the charging unit (3) and is captured by the filter unit, that is, the nonwoven fabric (2) that has been positively charged, and as a result, the filter unit (2) Releases purified air.

The filter section constituting the air purification device of the present invention is an element having a plurality of (many) openings through which air can pass, and is a section for trapping fine substances contained in the air. The filter unit is made of a non-woven fabric capable of positive electrostatic charge so as to efficiently capture negatively charged fine substances. For example, a metal thin plate (for example, a honeycomb-shaped thin plate) having a large number of fine openings can be used as the filter capable of positive electrostatic charge, but this is not advantageous in terms of cost. Therefore, in the present invention, a nonwoven fabric is used as a filter.
The material of the nonwoven fabric is not particularly limited as long as it can generate positive electrostatic charges. For example, a nonwoven fabric made of various chemical fibers or a metal fiber can be used.

Although it is not intended to limit or limit the present invention, the capture of the fine substance is performed by collision (adsorption) of the fine substance with the material (for example, metal fiber) constituting the filter portion and collision of the captured fine substance. It may also be achieved by (adsorption) and / or electrical suction between the fine substance and the filter part. In addition, the fine substance that is attached to the filter part by being captured by the filter part is positively electrostatically charged together with the filter part,
It is considered to play a role of capturing the fine substance contained in the air passing later together with the filter portion.

In the present invention, it is particularly desirable to use a nonwoven fabric made of metal fibers (hereinafter sometimes referred to as a metal nonwoven fabric) as a filter. The metal non-woven fabric is easily charged, and after capturing the fine substance, the captured fine substance can be easily removed from the non-woven fabric by washing or baking at a high temperature, so that repeated use, that is, regeneration is possible. . The metal fibers constituting the nonwoven fabric may be those made of iron, copper, aluminum or the like. Among them, aluminum is the most preferable material because it hardly corrodes, has a high melting point, and is lightweight.

The finer the fibers constituting the non-woven fabric and the smaller the size of the opening formed by the fibers, and the higher the fiber density of the non-woven fabric, the higher the effect of trapping fine substances. Use of too thin fibers or nonwoven fabric having a high fiber density is not preferable because resistance increases. In the present invention, a non-woven fabric having a weight per square meter of 400 g to 2500 g and a thickness of 1 mm to 5 mm, particularly a non-woven fabric of aluminum fiber, has a cross-sectional diameter (hereinafter referred to as a fiber diameter) of a fiber constituting the non-woven fabric of 0.1 mm.
It is preferable to use a nonwoven fabric having a thickness of from 05 mm to 0.5 mm. The more preferable fiber diameter of the fiber constituting the nonwoven fabric is 0.1.
It is between 08 mm and 0.12 mm.

Since nonwoven fabrics made of chemical fibers are generally difficult to wash and cannot be baked at a high temperature, it is difficult to remove fine substances once captured from the nonwoven fabrics. Therefore, a nonwoven fabric made of chemical fibers is not optimal for repeated use, but can be used when the filter portion is disposable or when the nonwoven fabric can be washed.

The air passing means constituting the air purifying device of the present invention may be any device as long as it allows air containing fine substances to pass through the filter section. Examples of such a device include a blowing means such as an electric fan or an air suction device. By sending air to the filter using an electric fan,
Air is passed through the filter section from the side where the electric fan is installed to the other side. On the other hand, by sucking air from one surface side of the filter unit using an air suction device, the air is filtered from the opposite surface where the suction device is installed to the surface on the side where the suction device is installed. Is passed across. Further, if the air flow is formed naturally and the momentum of the flow is sufficient to allow the air to pass through the filter section, the air passing means may be omitted.

The charging section constituting the air purifying apparatus of the present invention is means or an apparatus for positively charging the non-woven fabric of the filter section with a positive electrostatic charge. Specifically, the positive pole of the dry cell,
The non-grounded pole of the household AC power supply, the positive pole of the rectifier when the household AC power supply is connected to the rectifier, the high-voltage static electricity generator, etc. are electrically connected to the non-woven fabric of the filter using a conducting wire. It is possible to make this non-woven fabric positively charged. In this case, the higher the voltage at the time of charging, the higher the trapping ability of the filter section is. However, even if the battery is charged at a voltage of about 1.5 V using a dry battery, the trapping capacity of the fine substance of the filter section is sufficient. Is recognized. It is preferable that such a charging unit has a positive voltage of, for example, 1.0 to 200 V.
More preferably, the voltage is 100 V, particularly a voltage easily obtained using a dry battery, for example, 1.3 to 10 V. Also,
It is preferable to use a low voltage also from the viewpoint of safety.

When charging a chemical fiber non-woven fabric, it is necessary to generate a high voltage electric field. However, when a metal non-woven fabric is used, the entire non-woven fabric can be easily charged even at a low voltage. Use is also preferred from the point of energy efficiency.

The charging section is not limited as long as the charging section can charge the filter section. For example, the charging section may be connected to the filter section by using a long conducting wire, and may be installed in a place away from the space for purifying air. Good.

Next, the air purification method of the present invention will be described. The air purification method of the present invention is performed using the above-described air purification device. The air to be purified is passed across the filter section by air passing means, for example an electric fan. At this time, since the filter unit is electrically connected to the charging unit and is positively charged, negatively charged fine substances contained in the air are adsorbed to the filter unit by Coulomb force. Further, it is considered that the fine substance may be trapped in the filter part by colliding with the material constituting the filter part and / or the fine substance trapped in the filter part. Further, by making the nonwoven fabric positively charged, the air resistance is reduced, and the efficiency of capturing fine substances is further improved.
Therefore, purified air is released from the filter unit.

The air purifying apparatus of the present invention is as described above, does not require complicated parts or devices, and is not large-scale. Further, according to the air purification method of the present invention, air can be easily purified.

[0022]

The present invention will be described below with reference to examples.

Example 1 An apparatus as shown in FIG. 1 was manufactured according to the present invention. In this device, as the air passing means (1), the air flow rate is 500
Using a small fan of 0 l, the filter part (2)
1. Thickness made of aluminum fiber having a fiber diameter of 0.1 mm.
An aluminum nonwoven fabric (manufactured by Arum Co., Ltd.) having a size of 6 mm and a weight of 2000 g per square meter was used. FIG.
Shows an apparatus using two 1.5V single dry batteries as the charging unit (3). In this embodiment, in addition to this, a non-woven fabric is added to a non-woven fabric by using a 100V household AC power supply and an electrostatic charge is added. Tests were also performed for the case where the nonwoven fabric was charged and the case where the nonwoven fabric was positively charged using a 20,000 volt electrostatic generator. Further, for comparison, tests were performed on a filter using an aluminum foil honeycomb structure generally used for cotrel and a filter using a paper filter of a household ventilation fan.

In the present embodiment, the above-described device is installed in a normal house.
It was installed in a tatami room, and the number of microorganisms falling from the air was measured before and after a certain period of time after the start of operation. The number of falling microorganisms was measured by placing a medium containing peptone agar in a petri dish having a diameter of 9 cm for 30 minutes between 8 tatami mats and then heating at 30 ° C for 7 minutes.
After culturing for 2 hours, the number of colonies was counted. Table 1 shows the results.

[0025]

[Table 1]

Example 2 The same air purification device as that used in Example 1 was installed between 8 tatami mats in a normal house, and before the start of operation and two hours after the start of operation, the particle size falling from the air was reduced to 0. The number of fine substances of 0.2 to 1 μm and the number of fine substances having a particle size larger than 1.0 μm were measured. The number of fine substances was counted by placing a hematometer in a petri dish having a diameter of 9 cm, and microscopically measuring the fine substances that had fallen thereon. The counting was performed at three places, and the average value was defined as the number of falling fine substances. Table 2 shows the results.

[0027]

[Table 2]

[0028]

The air purifying device of the present invention is economical because it is compact and easy to handle and does not require complicated parts or devices. The use of this device makes it possible to easily and efficiently remove airborne or existing fine substances in the air to purify the air. Therefore, the device of the present invention can be used in general homes, hospital rooms of small and medium-sized hospitals and the like where it is difficult to use the conventional air purification device.

[Brief description of the drawings]

FIG. 1 schematically illustrates an example of an air purification device of the present invention.

[Explanation of symbols]

1. . . 1. air passage means; . . Filter section,
3. . . Charging unit.

Claims (7)

[Claims] 1. A device comprising a filter section, means for passing air to be purified across the filter section, and a charging section, wherein the filter section is a non-woven fabric capable of positive electrostatic charge. Air purifier for removing air. 2. The electrostatic air purification device according to claim 1, wherein the nonwoven fabric is a metal nonwoven fabric. 3. The electrostatic air purification device according to claim 2, wherein the metal nonwoven fabric is made of aluminum fibers. 4. The electrostatic air purifying apparatus according to claim 1, wherein the means for passing air to be purified across the filter section is a blowing means, preferably a fan. 5. The electrostatic air purifying apparatus according to claim 1, wherein the fine substance is a microorganism. 6. The electrostatic air purification device according to claim 1, wherein the charging unit has a positive voltage of 1 to 10 V. 7. A method for purifying air using the electrostatic air purifier according to any one of claims 1 to 6, wherein the non-woven fabric which is a filter part is added by a charged part. An electrostatic air purification method, characterized in that the air to be purified is passed through a filter section which is charged with an electrostatic charge and crosses a positively charged filter section.