JPS6223459A - Electric precipitator - Google Patents

Abstract

PURPOSE:To enhance the collection efficiency of charged dust particles and to make it possible to keep said effiency for a long period of time, by successively and alternately arranging electret filters and metal net like electrodes in this order in the downstream side of a charge part and constituting an electric field between two metal net like electrodes. CONSTITUTION:The dust particles flowing in a charge part where corona discharge is generated between the discharge wires 3 and opposed electrodes 4 are positively charged to be collected by electret filters 6, 8. At this time, an electric field directing from the downstream side to the upstream side has been generated between an upstream side metal net like electrode 7 and a downstream side metal like electrode 9 and the charged dust particles receive force in the reverse direction to pass through the filter 8 at a slow speed and, therefore, collection efficiency is enhanced. Because the polarization of the electret filter 8 is promoted by the electric field, the reduction of charge due to the adhesion of dust particles and the mutual negation of charge is reduced and high efficiency can be kept.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrostatic precipitator that charges and collects dust particles.

Prior Art A conventional electrostatic precipitator has a configuration as shown in FIG. In FIG. 3, inside the electrostatic precipitator outer frame 11, a charging section 16 is provided on the upstream side with respect to the air flow 12, and an electret filter 16 is provided on the downstream side. The charging section 15 consists of a discharge wire 13 and a counter electrode 14, and a DC high voltage power supply 17 is provided between the discharge wire 13 and the counter electrode 14, and (+) is connected to the discharge wire 13 and (-) is connected to the counter electrode 14. (Japanese Unexamined Patent Publication No. 16856/1983).

In the above configuration, when the air flow 12 containing dust particles flows into the charging section 15 by a blower or the like, a high DC voltage of Oite discharge wire 13K (+) is applied to the charging section 16 and (-) is applied to the counter electrode 14. Therefore, (+) corona discharge occurs,
The dust particles are charged (+) by this corona discharge.

These charged dust particles are attracted by the electrostatic force of the P material of the electret filter 16 disposed on the downstream side, and the dust particles are collected.

Problems to be Solved by the Invention However, in the conventional configuration, when charged dust particles adhere to the door material of the electret filter 16, the electric charge of the dust particles and the electric charge of the electret filter 16 cancel each other out, weakening the electrostatic force and making it impossible to capture the dust particles. This results in a decrease in collection efficiency.

In other words, the efficiency is very high at the beginning, but as the collection progresses, the efficiency decreases. There was also the problem that the collection efficiency of mechanical filters was low for particles.The present invention solves this problem by maintaining high efficiency and reducing the dust collection efficiency. The purpose is to suppress this and extend lifespan.

Means for Solving the Problem In order to solve this problem, the electrostatic precipitator of the present invention has the following features:
A charging section consisting of a discharge wire, a counter electrode plate, and a DC high-voltage power supply is provided on the upstream side of the air flow, and two sets of electret filters and wire mesh electrodes are provided on the downstream side, as seen from the upstream side.

The wire mesh electrodes are arranged alternately in this order, and the discharge wire and the downstream wire mesh electrode, and the counter electrode plate and the upstream wire mesh electrode are set to the same potential.

With this configuration, dust particles charged in the charging section are collected by the upstream electret filter, and some of the particles that are not collected are also collected by the downstream electret filter in the electric field formed by the two wire mesh electrodes. It is collected by the filter, maintaining high efficiency and extending its life.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2.

In FIG. 1, a charging section 5 consisting of a discharge wire 3 and a counter electrode plate 4 is provided inside the outer frame 1 on the upstream side with respect to the air flow 2. On the downstream side, in order from the upstream side, there is an electret filter 6, an upstream wire mesh electrode 7, and a downstream electret filter 8. A downstream wire mesh electrode 9 is arranged. A DC high-voltage power supply 10 is provided outside the outer frame 1, and the (+) side of the DC high-voltage power supply 10 is connected to the discharge M3 and the downstream wire mesh electrode 9, and the (-) side is connected to the opposing electrode plate 4 and the upstream wire mesh electrode 9. It is connected to the side wire mesh electrode 7.

In the above configuration, when the airflow 2 containing dust particles flows into the charging section 5 by a blower or the like, the charging section 5:
A corona discharge occurs between the discharge wire 3 and the counter electrode plate 4, and the dust particles are positively charged by this corona discharge. The charged particles are attracted and collected by the polarized upstream electret filter 6 by electrostatic attraction. The upstream electret filter 6
Most of the dust particles are collected by this, but some of the dust particles that pass through are collected by the downstream electret filter 8 in the same way. At this time, a high voltage is applied between the upstream wire mesh electrode 7 and the downstream wire mesh electrode 9 by the DC high voltage power supply 10, creating an electric field.

This electric field is oriented from the downstream side to the upstream side, and the positively charged dust particles receive a force in the opposite direction to the direction of the air flow 2, and the downstream electrets move at a speed slower than the speed of the air flow 2. Since it passes through the filter 8, the collection efficiency is improved compared to when no electric field is generated.

Furthermore, since the downstream electret filter 8 is disposed in the electric field, the polarization of the electret filter is promoted, so that the charges on the electret filter are less likely to be reduced by canceling each other out due to the attachment of dust particles. It is possible to maintain high efficiency.

FIG. 2 is a graph comparing the dust collection efficiency of the electrostatic precipitator according to the present invention and a conventional electrostatic precipitator. As shown in this graph, the product of the present invention has a much higher initial dust collection efficiency than the conventional product (99.97% for the product of the present invention, 96% for the conventional product). In addition, the efficiency of the product after collecting dust for 2Q cigarettes is almost unchanged (99.5%).
Compared to that of the conventional product, it has decreased to around 73 coefficients.

As described above, it can be seen that the product of the present invention has high efficiency and maintains this high efficiency for a long period of time.

Effects of the Invention As described above, according to the present invention, by alternately arranging the electret filter and the wire mesh electrode, an electric field is applied to the electret filter to promote polarization and increase the collection efficiency, and the efficiency can be maintained for a long period of time. can do. Further, the electric field can reduce the speed of charged dust particles and improve adsorption to the electret filter.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the configuration of an electrostatic precipitator according to an embodiment of the present invention, FIG. 2 is a graph showing changes over time in collection efficiency between the present invention and a conventional electrostatic precipitator, and FIG. 3 1 is a sectional view showing the configuration of a conventional electrostatic precipitator. 3...Discharge wire, 4...Counter electrode plate, 5...
...Charging section, 6... Upstream electret filter, 7... Upstream wire mesh electrode, 8...
...Downstream electret filter, 9...-
Downstream side wire mesh electrode, 10... DC high voltage power supply. Name of agent: Patent attorney Toshio Nakao and 1 other person5-
--riT Saibu

Claims (1)

[Claims] A charging section consisting of a discharge wire, a counter electrode plate, and a DC high-voltage power source is provided on the upstream side of the air flow, and an electret filter and a wire mesh electrode are arranged alternately on the downstream side in this order as viewed from the upstream side. An electrostatic precipitator in which the electric wire and the downstream wire mesh electrode, and the opposing electrode plate and the upstream wire mesh electrode are set at the same potential.