JP2002143719A - Electrostatic precipitation unit and air cleaner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic precipitation unit, in which a prefilter fitted to an outer casing can be omitted and also both the prefilter and the electrostatic precipitation unit are washed simultaneously and a role as the grounded electrode of an ionization part can be kept in the prefilter. SOLUTION: A prefilter 10 is fitted in the preceding stage of an ionization part 2 and both the same 2 and a dust collection electrode part 3 are fitted to the same case and are made to an integral structure. The prefilter 10 is made of a conductive plastic or a metal and is grounded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric dust collecting unit for ionizing dust and the like and collecting dust by static electricity, and an air cleaner using the same.

[0002]

2. Description of the Related Art Conventionally, in an air purifier, an electric precipitator is built in a case together with a fan and a control unit to form an air purifier. Apart from this, it is often attached to the outer case of an air purifier, and has a structure different from the electric dust collection unit. In other words, conventionally, even if there is a pre-filter in the air intake section of the air purifier,
Since there is no filter in the electrostatic precipitating unit itself, when large dust enters the inside of the electric precipitating unit, an abnormal discharge or a fire may be caused.

[0003] In general, the electric dust collecting unit needs to be cleaned periodically because dust collecting performance is reduced when the dust collecting electrode surface is contaminated by collecting dust. At the same time, the pre-filter is contaminated by dust and needs to be cleaned.

[0004]

SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to eliminate the need for a pre-filter attached to an outer case and to simultaneously clean the pre-filter and the electric dust collection unit. It is to make.

[0005] Conventionally, pre-filters are often made of an insulating plastic material. In order to avoid damage and burning due to discharge at the ionized portion of the electrostatic precipitating unit, the pre-filter is separated from the precipitating unit and has a different structure. It plays only the role of collecting large dust.

Therefore, a second object of the present invention is to provide a pre-filter integrated with an electrostatic precipitator unit so that it can also serve as a ground electrode for an ionization unit of the electric precipitator unit, thereby increasing the discharge space. The object is to ensure that dust and the like passing through the ionization section can be efficiently ionized.

When the pre-filter is made of a plastic material, the pre-filter has some elasticity and is not deformed by a slight impact, but has a problem in strength. on the other hand,
When made of metal, it may be deformed by a slight impact. For this reason, a metal filter generally used is a strong filter such as expanded metal.In this case, the thickness of the metal part forming the eye becomes large, so that the pressure loss of the air flow increases and the noise decreases. It is often disadvantageous from the viewpoint of energy saving.

Therefore, a third object of the present invention is to provide a pre-filter integrated with an electric dust collecting unit with a structure resistant to impact and reducing a pressure loss due to the structure.

[0009] The ionization section of the conventional electric dust collection unit is
A high DC voltage is applied to ionize dust passing therethrough. However, it is difficult to decompose odorous gas and the like with a DC high voltage because the instantaneous current value is small.

Therefore, a fourth object of the present invention is to ionize dust and simultaneously decompose odor gas and the like.
The instantaneous current value is made larger than in the case of only the DC high voltage, and the deodorizing ability can be enhanced by promoting the chemical reaction and promoting the decomposition treatment of the odorous gas.

A fifth object of the present invention is to provide an air purifier in which the electric dust collecting unit has solved the above-mentioned problems.

[0012]

According to a first aspect of the present invention, there is provided an electric dust collecting unit including an ionizing section and a dust collecting electrode section. A pre-filter is provided at a stage preceding the unit to form an integral structure with the ionization unit and the dust collection electrode unit.

According to a second aspect of the present invention, in order to achieve the first object, in the electric dust collecting unit according to the first aspect, the pre-filter is attached to the same case as the ionization section and the dust collecting electrode section. It is characterized by the following.

According to a third aspect of the present invention, in order to achieve the second object, in the electric dust collecting unit according to the first or second aspect, the pre-filter is made of conductive plastic or metal and is grounded. It is characterized by having done.

According to a fourth aspect of the present invention, in order to achieve the third object, in the electric dust collecting unit according to the first, second or third aspect, a plurality of pre-filters having different meshes are provided. It is characterized in that a plurality of filter elements are stacked.

According to a fifth aspect of the present invention, in order to achieve the fourth object, in the electric dust collecting unit according to the first, second, third or fourth aspect, the voltage applied to the ionization section is controlled by a direct current. And a waveform in which an AC or a pulse is synthesized.

According to a sixth aspect of the present invention, there is provided an air purifier for achieving the fifth object.
And an electric dust collection unit according to any one of the above.

[0018]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a two-stage charging type electric dust collecting unit according to the present invention. This electric dust collection unit 1
Are the ionization section 2, the dust collection electrode section 3, and the ionization section 2
And a high-voltage power supply 4 for applying a high voltage to the dust collecting electrode unit 3.

The ionization section 2 ionizes dust by corona discharge between an ionization wire (high voltage electrode) 5 which is a metal wire such as tungsten and a ground electrode 6 which is a metal plate such as aluminum or stainless steel.

The dust collecting electrode section 3 has a high voltage electrode 7 and a ground electrode 8 which are laminated to face each other with a space between them by a spacer 9, and adsorbs dust ionized by the ionizing section 2 by electrostatic force. .

As shown in FIG. 2, the electric precipitating unit 1 is provided with a pre-filter 10 at a stage preceding the ionizing section 2 so that the pre-filter 10 is integrated with the pre-filtering section 2 and the precipitating electrode section 3. Has become. That is, the pre-filter 10
Is attached to the same case as the ionization unit 2 and the dust collection electrode unit 3 on the upstream side of the ionization unit 2.

As shown in FIG. 3, the pre-filter 10 integrated with the electrostatic precipitator unit 1 is made of conductive plastic or metal, and when it is grounded, it can function as a ground electrode. That is, since the pre-filter 10 is made of a material through which electricity flows,
Also, since it is integrated with the electric dust collection unit 1,
The pre-filter 10 can be installed at a distance close to the ionization line 5.
Is grounded, the same function as the ground electrode 6 of the ionization section 2 can be performed.

When the pre-filter 10 is grounded, if it is made of metal, it is sufficient if somewhere on the surface is grounded.
In the case of plastic, since the resistivity is higher than that of metal, a metal terminal is provided separately.

FIG. 4A is a schematic diagram showing a discharge region when the pre-filter 10 is not provided. In this case, lines of electric force extend from the high-voltage electrode 5 to the ground electrode 6. FIG.
(B) is a schematic diagram when the pre-filter 10 is grounded.
The discharge region is wider than in FIG. Since the discharge region is widened, it is possible to increase the ionization efficiency even with the same volume. Further, since the discharge region is widened, the deodorizing effect is improved.

When the pre-filter 10 is made of metal,
A plurality of metal filter elements 10a and 10b having different roughnesses as shown in FIGS.
It is preferable to have a superposed structure as shown in FIG. This is for the following reasons.

Generally, a metal filter has a structure in which a hole is formed by a press or a metal thread is knitted. However, in the case of forming a hole by pressing, it is difficult to increase the opening area because it is necessary to make a large hole in an attempt to increase the opening area. . On the other hand, in the case of a structure in which metal yarns are knitted, the yarns are knitted with as thin a yarn as possible in order to increase the opening area, and thus there is a problem in strength. For these reasons, there is a problem in incorporating a metal filter into the electric dust collection unit 1 as a single product.

Therefore, a fine metal net is
When a metal net having larger eyes and a larger thickness is superimposed as a filter element, a prefilter having both the original function and strength as a filter can be obtained.

FIG. 6 shows a waveform of a high voltage applied from the high voltage power supply 4 to the ionization unit 2 of the electric dust collection unit 1. FIG. 6A shows a voltage waveform of a normally used DC power supply. The voltage value is several kV. In the present invention, a high voltage obtained by combining an AC voltage waveform with a DC waveform as shown in FIG. 6B or a high voltage obtained by combining a pulsed voltage waveform as shown in FIG. 6C is applied to the ionization section 2. I do. By changing the waveform of the high voltage applied to the ionization unit 2 in this manner, the dust is ionized,
The chemical reaction of the gas passing through the ionization section 2 can be promoted. Thus, the odorous gas can be decomposed and deodorized. This is for the following reasons.

The current increases when the electric field and the potential change with time are large. Also, when a high voltage is applied to the space,
An electric field is generated in the space, and electrons are emitted into the space.
Electrons existing in space have very large energy because they are accelerated by an electric field. When electrons collide with gas molecules, the gas molecules cause a chemical reaction. In order for this chemical reaction to occur more efficiently, it is necessary to increase the number of electrons existing in space or increase the energy possessed by the electrons.

Therefore, when an AC or pulse voltage is combined with a DC voltage, the current flowing instantaneously increases. As the current increases, the number of electrons in the space increases,
Because the probability of collision with gas molecules existing in space increases,
It can promote chemical reactions.

[0032]

The advantages of the present invention are as follows for each claim. (Claims 1 and 2) Since the prefilter is formed integrally with the electric dust collecting unit, the prefilter attached to the outer case can be omitted, and the prefilter and the electric dust collecting unit can be simultaneously cleaned.

(Claim 3) Since the pre-filter integrated with the electric precipitating unit is grounded as conductive plastic or metal, the pre-filter can also serve as a ground electrode for the ionization section. A large discharge area can be ensured even in volume, and dust and the like passing through the ionization section can be efficiently ionized.

(Claim 4) Since the pre-filter integrated with the electric precipitating unit is constituted by laminating a plurality of filter elements having different coarsenesses, the filter structure has a small pressure loss and is strong against impact. Can be.

(Claim 5) Since the voltage applied to the ionization section is a waveform obtained by combining an AC waveform or a pulse waveform with a direct current, the decomposition of the odorous gas can be promoted.

(Claim 6) It is possible to provide an air purifier using the electric dust collecting unit having the above effects.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of an electric dust collecting unit according to the present invention.

FIG. 2 is a schematic configuration diagram of an electric dust collecting unit according to the present invention integrated with a pre-filter.

FIG. 3 is a schematic configuration diagram when a pre-filter is made conductive and grounded.

FIG. 4 is a schematic diagram of lines of electric force in an ionization unit;
(A) shows a case without a pre-filter, and (B) shows a case with a pre-filter.

5 (A) and 5 (B) are diagrams showing filter elements having different roughnesses, and FIG. 5 (C) is a diagram showing a pre-filter in which these filter elements are superimposed.

6A is a diagram illustrating a voltage waveform of a DC voltage, FIG. 6B is a diagram illustrating a voltage waveform obtained by combining an AC voltage with a DC voltage, and FIG. 6C is a diagram illustrating a voltage waveform obtained by combining a pulse voltage with a DC voltage.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric dust collection unit 2 Ionization part 3 Dust collection electrode part 4 High voltage power supply 5 Ionization wire 6 Ground electrode 7 High voltage electrode 8 Ground electrode 9 Spacer 10 Prefilter 10a ・ 10b Filter element

Claims (6)

[Claims] 1. An electric precipitating unit comprising an ionizing section and a dust collecting electrode section, wherein a pre-filter is provided at a stage preceding the ionizing section to form an integral structure with the ionizing section and the dust collecting electrode section. Characterized by an electric dust collection unit. 2. The electrostatic precipitating unit according to claim 1, wherein the pre-filter is mounted on the same case as the ionizing section and the precipitating electrode section. 3. The electrostatic precipitating unit according to claim 1, wherein the pre-filter is made of conductive plastic or metal and is grounded. 4. The electrostatic precipitating unit according to claim 1, wherein the pre-filter is configured by stacking a plurality of filter elements having different meshes. 5. The electrostatic precipitating unit according to claim 1, wherein the voltage applied to the ionization unit has a waveform obtained by combining a direct current with an alternating current or a pulse. 6. An air purifier comprising the electric dust collection unit according to claim 1.