JPH0377655A - Air cleaner - Google Patents

Abstract

PURPOSE:To improve the dust collecting efficiency and to prolong the life of filter by disposing electret filters accompanied with metallic nets in wave form, and dielectrically polarizing the electret filters having lost the dielectric force by collecting charged particle. CONSTITUTION:The discharge part 1 provided in the upstream side of air flow consists of high potential dischage lines 2, earthed metallic electrode plates 3, and high potential electric power source 4. In the dust collecting part 5 provided in the downstream side of air flow, the electret filters 6 are disposed in wave form and high potential discharge lines 7 and metallic nets 8 are provided respectively in upstream side and downstream side so that the filters are between them, and high potential is impressed to the high potential discharge lines 7 from an electric power source 9. Thus, by raising the effective area of electret filter to reduce the wind velocity passing through the filters, the pressure loss is reduced and the dust collecting efficiency is improved, and, by impressing high potential to the high potential discharge lines 7, the filters having lost the dielectric force are dielectrically polarized to collect charged particles again by the dielectric force.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an air cleaning device for collecting dust particles in the air.

Conventional technology The configuration of the conventional example will be explained below with reference to FIG.

In air purification, an electrostatic method is sometimes used to collect dust particles. For example, as shown in Japanese Patent Application Laid-Open No. 15856/1985, dust particles in the air are charged and then collected by an electret filter using electrostatic force. Proposals have been made to collect dust particles. 51 is an outer frame of the air purifier main body, 52 is a charging section, and 53 is an electret filter.

The charging section 52 consists of a discharge wire 54 and a parallel plate electrode 55, and discharges! 1154 and the parallel plate electrode 55, plus the discharge wire 54 from the DC high voltage power supply 56, the parallel plate type 11i
The configuration is such that the negative terminal is connected to 55.

In the above configuration, when the airflow 57 containing dust particles flows into the charging section 52 from a blower or the like, the discharge wire 54 is exposed to +(
Since a - (minus) DC high voltage is applied to the parallel plate electrode 65, a + corona discharge occurs between the discharge 4154 and the parallel plate electrode 55, and the inflowing dust particles are caused by the corona discharge. charged to ten. These highly charged dust particles were attracted and collected by electrostatic force to one side of the dipole polarizer of the filter medium 58 of the electret filter 53 as shown in FIG.

Problems to be Solved by the Invention In such a conventional configuration, since the electret filter 53 has a flat shape, the filter area is small, and when trying to secure air volume, pressure loss is large and dust particle collection efficiency is poor. There was a problem.

Furthermore, as shown in FIG. 6, since the collection of charged dust particles is carried out only by the filter material 58 (-@) of the electret filter 53, the charge of the mud material 58 to which the charged particles adhere and the charge of the dust particles is electrically neutralized, the electrostatic force of the electret filter 53 is weakened, and the collection efficiency is reduced.

In other words, if the weight of the filter is reduced to reduce the pressure loss, the initial dust collection efficiency will be lower, and as dust accumulates, the dust collection efficiency will drop significantly, resulting in a shorter service life and shorter replacement time. There was a problem. Therefore, in an air purifier using an electret filter as a filter medium, the pressure loss is small, the initial dust particle collection efficiency is good, the electrostatic force of the electret filter is maintained, and the drop in dust collection efficiency is suppressed. The challenge is to extend lifespan.

In view of the above problems, the present invention is an air purifier that reduces pressure loss, improves the initial dust particle collection efficiency, maintains the electrostatic force of the electret filter, suppresses the decrease in dust collection efficiency, and extends the life of the electret filter. It provides:

Means for Solving the Problems In order to solve the above problems, the present invention provides a charging section consisting of a discharge wire, a parallel plate electrode, and a DC high voltage power supply on the upstream side with respect to the air flow, and an electret on the downstream side. The electret filter is arranged in a wave shape so as to cross the ventilation path, a discharge wire is provided on the upstream side of the electret filter, and a metal net is provided on the downstream side of the electret filter, and the metal net is arranged in waves along the electret filter. A voltage is applied to the discharge wire, the metal net is grounded, and an electric field is applied to the electret filter by the discharge wire and the metal net.

Effect of the present invention With the above-described configuration, the effective area of the electret filter is increased and the wind speed passing through the electret filter is reduced, thereby reducing pressure loss and increasing collection efficiency. By applying a
This allows charged dust particles to be further collected by electrostatic force, extending the life of the electret filter. EXAMPLE An example of the present invention will be described below with reference to FIG.

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

In FIG. 1, 1 is a discharge section provided on the upstream side of the airflow, and a high voltage discharge $u12. Counter electrode ground metal plate 3. The high voltage discharge is caused by the high voltage power supply 4 applying a high voltage to li[2.

5 is a dust collection section provided on the upstream side of the airflow, and there is an electret filter 6 attached in a waveform shape, and a high voltage discharge 11i [7 on the upstream side, sandwiching the electret filter 6], and a metal net on the downstream side. There are 8
High voltage discharge on the upstream side! A high voltage is applied to 7 from a high voltage power supply 9. Further, 10 is a pre-filter provided on the upstream side of the airflow of the discharge section 1.

Figure 1 shows the air purifying device configured as described above.
This will be explained using FIG.

First, turn on the operation switch of the air purifier (Stap
l).

A high voltage of 10 is applied to the high voltage discharge 1!2 by the high voltage power supply 4, and a discharge current flows from the high voltage discharge ItllI2 to the counter ground metal electrode plate 3, forming an ionized region. Airborne particles in the air are taken into the air cleaning device along with the air by an air shield blowing device (not shown) included in the device.
First, coarse particles 11 such as cotton dust having a large particle size are removed by a pre-filter 10. Pre-filter
The fine particles 12 that have passed through the ionization area 10 are sufficiently charged due to repeated collision ionization of electrons and ions released in the ionization area and diffusion of ions when passing through the ionization area described above, and become charged particles 13.
(Step 2).

When the charged particles 13 approach the electret filter 6 arranged in a wave shape, the charged particles 13 are attracted to one side of the dipole polarizer of the electret filter 6 by electrostatic force and collected (Step 3).

Therefore, when the charged particles 13 adhere to the electret filter 6, the negative charge of the filter medium is electrically neutralized by the positive charge of the charged particles 13, but the high voltage discharge 1j provided upstream of the electret filter 6
When voltage is applied to 17, the electret filter 6
An electric field is generated between the electret filter 6, which has collected dust and lost its electrostatic force, and dielectrically polarizes the electret filter 6, which has collected dust and has lost its electrostatic force, making it possible to further collect charged particles 13 using the electrostatic force. (Stop 4).

Through the above process, the electret filter 6 is arranged in a wave shape, so the area of the filter material is larger than in the case of a flat shape, and the passing speed of the charged particles 13 when passing through the electret filter 6 is reduced. . Therefore, the time for the charged particles 13 to pass through the electret filter 6 becomes longer, and the electrostatic force and the passage speed of the mechanically collected charged particles 13 become smaller, thereby reducing the pressure loss caused by the electret filter 6. .

In addition, the electret filter 6 loses its electrostatic force due to the collection of charged particles 13, but by dielectrically polarizing the electret filter 6, it is possible to further collect the charged particles 13 by the electrostatic force. It has the effect of extending lifespan.

Effects of the Invention As described above, the present invention includes a charging section comprising a discharge wire, a parallel plate electrode, and a DC high-voltage power source on the upstream side of the air flow, and an electret filter on the downstream side, and The electret filter is arranged in a wave shape so as to cross the ventilation path, a discharge wire is provided on the upstream side of the electret filter, and a metal net is provided on the downstream side of the electret filter, and the metal net is arranged in a wave shape along the electret filter. , an air purifying device in which a voltage is applied to the discharge wire, the metal net is grounded, and an electric field is applied to the electret filter by the discharge wire and the metal net, and the following effects are obtained.

(1) Since the electret filter is arranged in a wave shape, the area of the filter medium is expanded. As a result, the speed at which dust particles pass through the electret filter is reduced for the same air volume, so that the dust particle collection efficiency of the electret filter is improved and pressure loss is reduced.

(2) The electret filter, which has lost its electrostatic force due to the collection of charged dust particles, is dielectrically polarized, making it possible to further collect charged dust particles by the electrostatic force, thereby extending the life of the electret filter.

(3) By arranging the metal net along the electret filter, the dielectric polarization effect of the filter can be enhanced and the collection efficiency can be improved.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an air purifying device that is an embodiment of the present invention, Fig. 2 is a flowchart showing an example of air purification, and Fig.
The figure is a schematic diagram of a conventional air cleaner, and FIG. 4 is a schematic diagram showing the structure of an electret filter medium. 2.7...High voltage discharge wire, 3...Counter electrode ground metal plate, 4.9...High voltage power supply, 6...Electret filter.

Claims (1)

[Claims] A charging section consisting of a discharge wire, a parallel plate electrode, and a DC high-voltage power source is provided on the upstream side of the air flow, and an electret filter is provided on the downstream side, and the electret filter is arranged so as to cross the ventilation path and in a wave shape. A discharge wire is placed on the upstream side of the electret filter, and a metal net is provided on the downstream side of the electret filter, and the metal net is arranged in a wave shape along the electret filter. An air purifying device configured to apply an electric field to the electret filter using the discharge wire and the metal net.