JPS624453A - Device for displaying life of air filter - Google Patents

Abstract

PURPOSE:To display the life of an electret filter by providing an electric current detector between discharge wires and parallel plate electrodes in the electrically charged part on the upstream side of an air current. CONSTITUTION:In a device for displaying the life of an air filter for collecting dust particles in air, an electrically charged part 12 is provided on the upstream side of an air current 11 in the outer frame 10 of the filter and an electret filter 13 is furnished on the downstream side. The charged part 12 consists of discharge wires 14 and parallel plate electrodes 15. A DC high-voltage electric power source 16 is provided between the wire 14 and the electrode 15, an elec tric current detector 18 is furnished between the wire 14 and the power source 6, a lamp lighting device 19 is arranged and an electrically conductive filter 17 of a wire mesh, etc., is provided on the downstream side of the electret filter 13. The contaminated state of the electret filter is detected by the electric current flowing between the discharge wire and the parallel plate electrodes and a decrease in the dust collection efficiency, namely the life of the electret filter, is notified.

Description

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

2. Description of the Related Art Conventionally, this type of air filter has had a configuration as shown in FIG. That is, an air flow 8 is created inside the filter outer frame 1.
A charging section 2 is provided on the upstream side, and an electret filter 3 is provided on the downstream side.

The charging section 2 consists of a discharge wire 4 and a parallel plate electrode 5. A DC high voltage power source 6 is provided between the discharge wire 4 and the parallel plate electrode 5, and a DC high voltage power source 6 connects the discharge wire 4 to the parallel plate. A negative terminal is connected to the electrode 6. A conductive filter 7 such as a wire mesh is provided downstream of the electric filter 3 and is connected to the negative terminal of the DC high voltage power supply 6.

In the above configuration, an air flow 8 containing dust particles flows into the charging section 2 by a blower or the like. In the charging section 2, a positive DC high voltage is applied to the discharge wire 4 and a negative DC high voltage is applied to the parallel plate electrode 5, so that a positive corona discharge occurs between the discharge wire 4 and the parallel plate electrode 6. Charging section 2
The dust particles that have flowed into the chamber are charged to ■ by corona discharge.

These charged dust particles are attracted by electrostatic force to the O side of the dipole polarizer of the F material 9 of the electret filter 3 as shown in FIG. 2, and the dust particles are collected.

When dust particles adhere, the electric charge of the F material 8 and the electric charge of the dust particles are canceled in the adhered portion, and the electrostatic force of the electret filter 3 is weakened, resulting in a decrease in collection efficiency. However, by providing the conductive filter 7 downstream of the electret filter 3, an electric field is generated between the discharge wire 4 and the conductive filter 7, and the dust particles attached to the door material 9 of the electret filter 3 are polarized. This made it possible to extend the life of the electret filter 3 to some extent.

Problems to be Solved by the Invention In such a conventional configuration, when used for a long time, the electret filter 3 and the charging section 2 become dirty and the dust collection efficiency decreases. Therefore, depending on the degree of contamination of the electret filter 3, the time of use, etc., the replacement period of the electret filter 3, that is, the life span, has been displayed on the case of an air purifier using the filter. Although the level of dirt, usage time, etc. have some relationship to the reduction in dust collection efficiency, the phenomenon of reduction in dust collection efficiency greatly changes depending on usage conditions such as the amount of dust and the place of use. Therefore, even if the electret filter 3 has the same degree of contamination, the dust collection efficiency is 70%.
There was a problem that the lifespan was not clearly indicated to the user.

The present invention is intended to solve these problems, and aims to make the life of the electret filter 3 so that it can be clearly displayed.

Means for Solving the Problem In order to solve this problem, 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 of the air flow, and a charging section on the downstream side. An electret filter is provided, a conductive filter is provided downstream of the electret filter, and a current detector is provided to detect the current flowing between the discharge wire and the parallel plate electrode.

Function: With this configuration, the life of the electret filter is displayed from the relationship between the current and the dust collection efficiency by detecting the current flowing between the discharge wire and the parallel plate electrode.

Embodiment FIG. 1 is a sectional view of an air filter life display device according to an embodiment of the present invention. Inside the filter outer frame 10, with respect to the air flow 11, there is a charging section 12 on the upstream side and an electret on the downstream side. A filter 13 is provided. The charging section 12 is composed of a discharge wire 14 and a parallel plate electrode 16, and the discharge wire 1
A DC high-voltage power supply 16 is provided between the parallel plate electrode 16 and the DC high-voltage power supply 16, and a
A negative terminal is connected to the parallel plate electrode 15.

A conductive filter 17 such as a wire mesh is provided on the downstream side of the electret filter 13.1. It is connected to the negative terminal of the DC high voltage power supply 16. A current detector 18 is provided between the discharge line 14 and the DC high voltage power supply, and a lamp lighting device 19 that receives a signal from the current detector 18 is disposed.

In the above configuration, air flow 11 containing dust particles flows into charging section 12 by a blower or the like. As shown in the conventional example, the dust particles that have flowed into the charging section 12 are caused by a positive corona discharge between the discharge wire 14 and the parallel plate electrode 15.
(2) and collected by the electret filter 13. In addition, by the discharge wire 14 and the conductive filter 17,
Applying an electric field to the electret filter 13 can extend the life of the electret filter 13 to some extent, but if used for a long time, the electret filter 13 will get dirty and the dust collection efficiency will decrease. It has a strong electric field and influences the charging section 12. When the electret filter 13 is clean, it has a strong electric field, but if it is used for a long time and dust particles are attached to it, the electric field becomes weaker. Therefore, while the electret filter 13 has a strong electric field, it affects the charging section 13, and the voltage between the discharge wire 14 and the parallel plate electrode 15 is 8 KV and about 60 μA. The dust collection efficiency at this time was 90 qb. However, when the electret filter 13 gets dirty and the electric field weakens, the voltage between the discharge wire 14 and the parallel plate electrode 16 drops to about 7KV.
The current value becomes high at 140 μA. When a lot of current flows,
Although the charging effect of dust particles improves, the deterioration of the electret filter 13 makes a greater contribution, and the dust collection efficiency is reduced to 60%.
It decreases to about 1. Although it varies depending on the place of use, in a general household, the life of the electret filter 13 is about 60% dust collection efficiency, and the current flowing between the discharge wire 14 and the parallel plate electrode 15 is detected by the current detector 18, and it is 140 μA.
If the above occurs, a signal can be sent to the lamp lighting device 19 to light the lamp, thereby informing the user of the lifespan of the air filter (time to replace the electret filter 13).

Note that not only the current value but also the voltage changes (decreases), so it is also possible to detect the voltage or detect the current and voltage to notify the end of life.

In this way, this air filter life display device detects the current flowing between the discharge wire 14 and the parallel plate electrode 15 based on the relationship between the current value and the dust collection efficiency, rather than based on sensory information such as the degree of dirt on the electret filter 13. detection, decrease in dust collection efficiency,
That is, it is possible to notify the user of the lifespan (replacement time) of the electret filter 13 by an easy-to-understand method such as lighting a lamp.

Effects of the Invention As is clear from the above description of the embodiments, according to the present invention, the life of the air filter, that is, the time to replace the electret filter, can be determined by detecting the current flowing between the discharge wire and the parallel plate electrode. This provides the effect that the current can be set to the minimum allowable value of dust collection efficiency, and the user can be informed of the lifespan in an easy-to-understand manner.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an air filter life display device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing an electret filter P
FIG. 3 is an enlarged structural view for explaining the structure of the material, and FIG. 3 is a sectional view showing a conventional air filter. 12...Charging section, 13...Electret filter, 14...Discharge wire, 15...
...Parallel plate electrode, 16...DC high voltage power supply, 1
7... Conductive filter 18... Current detector. Name of agent: Patent attorney Toshio Nakao and 1 other person + 4
- One journey 15 - 11 and 9 towns

Claims (1)

[Claims] With respect to the air flow, 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, an electret filter is provided on the downstream side, and a conductive filter is provided on the downstream side of the electret filter. An air filter life indicator equipped with a current detector that detects the current flowing between the discharge wire and the parallel plate electrode.