JPH06182255A - Electrostatic precipitator - Google Patents

Abstract

PURPOSE:To increase the dust collecting efficiency by electrifying dust in dust- contg. air to collect it on an electrode. CONSTITUTION:A dust collecting pan having a dust-collecting high voltage electrode plate 3 and dust collecting grounded electrode plates 4 arranged facing each other is arranged on the downstream of an ionization part having a discharging wire 2 stretched across in a direction almost perpendicular to the air current direction and a semi-circular grounded electrode 1a having vents for allowing the diffusion of the air current. The air current passes the ionization part flows between the electrode plates 3, 9. DC high voltage V2 lower than that applied to the discharging wire 2 is applied to the high voltage electrode plate 3 by a power source 6. When dust-contg. air passes a charging zone 5, the dust in the dust-contg. gas is given a positive charge and further, attracted toward the dust-collecting grounded electrode plates 4 to be stuck on them by force of the electric field generated between the electrode plates 3, 4 on the downstream side. The, attracting force is increased with the increase in the charge. Consequently the dust collecting efficiency is improved.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a charging portion of an electrostatic precipitator for charging dust in dust-containing air and collecting the dust on electrodes.

2. Description of the Related Art As shown in FIG. 2, a conventional electrostatic precipitator has a structure in which a ground electrode plate is provided on both sides of a linear or rod-shaped discharge electrode in parallel with the discharge electrode, and an air flow is made to flow between the ground electrode plates. As the charging section,
A dust collecting part was provided on the downstream side of the charging part.

In the above prior art, since the distance from the discharge electrode to the ground electrode varies depending on the discharging direction, the electric field strength is not uniform, and the charging space filled with positive charges has a strong electric field strength. Since it is limited to parts, it becomes narrower. Therefore, there is a problem in that the amount of charge on dust is small and improvement in dust collection efficiency cannot be expected. That is, the ground electrode plate 1
Since b is a flat plate, the central part of the flat plate is close to the discharge line, and corona discharge is concentrated in this part and the charge band is narrowed. An object of the present invention is to provide an electrostatic precipitator that increases the amount of charges on dust and has high dust collection efficiency.

In order to achieve the above object, the present invention provides an electrostatic precipitator which is formed in a shape that allows discharge lines arranged in a direction substantially perpendicular to the direction of the air flow and a shape that allows the air flow to pass therethrough. An ionization part having a ground electrode arranged at a position where a charging space having a uniform electric field strength is formed between the discharge line and a dust collection part arranged downstream of the ionization part in the air flow. It is characterized by.

The discharge line and the ground electrode are arranged at positions where a charging space having a uniform electric field strength is provided between them, so that the electric field strength is substantially semicircular from the discharge line toward the ground electrode plate. Various charge zones are formed, uniform corona discharge is generated, and the amount of charges to the inflowing dust-containing air is increased. The charged dust is collected by the electric force in the dust collecting portion located downstream of the charged dust. Therefore, the larger the amount of charge, the higher the dust collecting efficiency.

EXAMPLES Examples of the present invention will be described below. A first embodiment of the present invention will be described with reference to FIG. The electrostatic precipitator of this embodiment has an ionization section and a dust collection section. The ionization part is formed in a semicircular shape by a discharge wire 2 stretched in a direction substantially perpendicular to the air flow direction and a wire mesh having a vent hole to allow the air flow to pass through, and is arranged at substantially the same distance from the discharge wire 2. An ionization part having a grounded electrode provided therein and a dust collection part having a flat plate-shaped electrode arranged in the air stream on the downstream side of the ionization part and parallel to the air flow direction. The discharge line 2 is stretched around the dust-containing air flow passing through the electrostatic precipitator at a position which is the most upstream of the flow and is approximately perpendicular to the air flow direction. On the downstream side of the discharge line 2,
The ground electrode plate 1a is arranged on a semicircular arc that is approximately equidistant from the discharge line 2. The ground electrode plate 1a is made of a wire mesh having a ventilation hole and is grounded. The discharge line 2 is a tungsten wire of about φ0.18 mm, and when a DC high voltage of voltage V ₁ is applied by the power source 6, a corona discharge is generated toward the ground electrode plate 1a and is surrounded by the ground electrode plate 1a and the discharge wire 2. A charge band 5 filled with positive charges is formed in a substantially semicircular shape. The inflowing dust-containing air is given a positive charge in the charging zone 5. Since the dust-containing air is temporarily blocked by the ground electrode plate 1a, it is given a residence time,
Further, since the charging zone 5 is substantially semicircular and large, the amount of positive charges given to the air flow passing through it by the ionization section of this embodiment is larger than that of the conventional parallel ground electrode. Downstream of the ionization part, a dust collection part having a dust collection high-voltage electrode plate 3 and a dust collection ground electrode plate 4 which are respectively arranged along the air flow direction so as not to obstruct the air flow is installed. Dust collecting high voltage electrode plate 3 and dust collecting ground electrode plate 4
Are arranged so as to face each other, and the airflow passing through the ionization section flows between these electrode plates. A DC high voltage V ₂ lower than the voltage applied to the discharge wire 2 is applied to the power source 6 on the dust collecting high-voltage electrode plate 3.
Is being applied by. The dust collecting ground electrode plate 4 is grounded. The dust in the dust-containing air is given a positive charge when passing through the charging zone 5 and is the electric field force generated between the dust-collecting ground electrode plate 4 and the dust-collecting high-voltage electrode plate 3 located further downstream. It is attracted and attached in the direction of the plate 4. This attracting force becomes stronger as the charge amount increases, and the dust collection efficiency increases. FIG. 3 is a graph showing the relationship between the voltage applied to the discharge line 2 and the ionization current. In order to obtain the required dust collection efficiency, a voltage of V ₁ was applied and a current of i ₁ was applied in the conventional ionization section using parallel plate electrodes. In this embodiment, when the same voltage V ₁ as that of the ionization section using the conventional parallel plate electrodes is applied, a current larger than the current i ₁ of the conventional ionization section can flow and the charge amount increases to collect dust. The efficiency can be improved. Further, in this embodiment, the charge zone 5 is substantially semicircular and the amount of positive charge given to the air flow passing therethrough is larger than that in the case of the conventional parallel ground electrode. Therefore, even if a voltage of V ₂ lower than V ₁ is applied. The current of i ₁ can be passed and the required dust collection efficiency can be obtained. Therefore, as shown in FIG.
The voltage applied to the dust collection high-voltage electrode plate 3 may be reduced to the same voltage as the voltage applied to the dust collection high-voltage electrode plate 3, whereby the cost of the power supply 6 can be reduced. Next, a second embodiment of the present invention will be described. FIG. 5 shows a second embodiment of the present invention in which a grounding electrode plate having a plurality of discharge lines 2 and a plurality of substantially semi-circular charge bands 5 corresponding to the discharge lines 2 is contained in one frame. FIG. 5A shows a front view of this embodiment.
(B) shows a side sectional view of the present embodiment. In this embodiment, four discharge wires 2 are stretched in a frame 8 in a state of being insulated from the frame 8 by insulators 7a and 7b. A ground electrode plate 1c is arranged on the downstream side of the discharge line 2. The ground electrode plate 1c is formed of a wire mesh and is bent in a wave shape so as to be arranged on a semi-circular arc centered on each discharge line 2. A high voltage is applied to the discharge line 2 by the power supply 6. In this way, the ground electrode plate 1c can be easily manufactured by securing the ventilation area by corrugating the wire mesh.

As described above, according to the present invention, since the amount of charges on dust is increased, the dust collection efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view in the air flow direction of an electrostatic precipitator according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional electrostatic precipitator in the air flow direction.

FIG. 3 is a graph showing a relationship between a voltage applied to a discharge wire and an ionization current of the electrostatic precipitator according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view in the air flow direction when the applied voltage is low in the electrostatic precipitator of the first embodiment of the present invention.

5A and 5B are a front view and a side sectional view of an electrostatic precipitator according to a second embodiment of the present invention. FIG. 5A is a front view and FIG. 5B is a side sectional view.

[Explanation of symbols]

1a, 1b, 1c ... Ground electrode, 2 ... Discharge wire, 3 ... Dust collecting high-voltage electrode plate, 4 ... Dust collecting ground electrode plate, 5 ... Charge band, 6 ... Power supply, 7
a, 7b ... Insulator, 8 ... Frame

Claims (3)

[Claims] 1. A discharge line arranged in a direction substantially perpendicular to the direction of the air flow, and a discharge line formed to have a shape that allows the air flow to pass therethrough. An electrostatic precipitator comprising: an ionization part having a ground electrode; and a dust collection part arranged on the downstream side of the ionization part in the air flow. 2. The ionization part has a discharge line arranged in a direction substantially perpendicular to the direction of the air flow and a ground electrode formed in a shape that allows the air flow to pass therethrough and arranged at a substantially equal distance from the discharge line. The electrostatic precipitator according to claim 1, which is characterized in that. 3. The electrostatic precipitator according to claim 2, wherein the ground electrode is disposed on the downstream side of the discharge line and on a substantially circumference centered on the discharge line.