JP3160490B2 - Wet electric dust collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet type electrostatic precipitator for cleaning a precipitating electrode by spraying.

[0002]

2. Description of the Related Art A schematic configuration of a conventional wet-type electrostatic precipitator is shown in FIGS. In the wet type electrostatic precipitator, the discharge electrode 1 (high-pressure side electrode) is provided between the precipitating electrodes 2 (ground side electrode) to form a dust collecting space. A high voltage is applied to the discharge electrode 1 from the DC high-voltage power supply 3 via the penetrating insulator 4, and a corona current flows between the discharge electrode 1 and the dust collection electrode 2. The processing gas is supplied to the dust collecting space.

[0003] Particles such as dust and mist introduced into the dust collecting space together with the processing gas are charged by the corona current flowing between the discharge electrode 1 and the dust collecting electrode 2 and at the same time, are charged between the electrodes 1 and 2. The particles move to the dust collecting electrode 2 side and are collected by the Coulomb force generated by the electric field generated at the time.

As shown in FIG. 3, the dust and mist that have moved and collected to the dust collecting electrode 2 side are sprayed from a plurality of nozzles 5 provided above the electrodes 1 and 2 (spray spray). ) Is washed off to the lower hopper 6 together with the falling liquid film on the dust collecting electrode 2.

In recent years, it has been required to reduce the size and cost of an electric dust collector, and to reduce the distance between the discharge electrode 1 and the dust collection electrode 2 (by using narrow spacing) to generate a large current. A wet electric precipitator that collects dust by supplying it has been considered.

[0006]

In a conventional wet-type electrostatic precipitator using narrow spacing, sparks occur frequently when the dust collecting electrode 2 is cleaned by spray spray as described above. In some cases, a voltage and a current sufficient to obtain a desired performance cannot be obtained.

That is, in the case of an electrostatic precipitator in which the dust collecting electrode 2 is washed from above by spray spray, the upper part of the dust collecting electrode 2 to which the spray droplets reach from the nozzle 5 as shown in FIG. The droplets rebound due to the collected dust and the like, and unevenness of the falling liquid film occurs.

When the distance between the dust collecting electrodes 2 (hereinafter, pitch) is relatively large, for example, 300 mm, the width of disturbance of the liquid film is apparently smaller than the pitch. However, the pitch is small, for example 2
When the thickness is less than 00 mm, the ratio of the turbulence width to the pitch becomes apparently large, so that a spark is easily induced.

As described above, in the conventional wet type electrostatic precipitator using the narrow spacing (the distance between the electrodes is narrow), a spark is generated at a low voltage, and thereafter, the spark frequently occurs with an increase in the voltage. At a certain voltage,
There has been a problem that the voltage and current cannot be increased and sufficient performance cannot be obtained.

The present invention has been made in view of the above circumstances, and has as its object to provide a wet-type electrostatic precipitator having improved performance by enabling application of high voltage and high current to electrodes. And

[0011]

According to the present invention, a particulate matter present in a dust collecting space is collected by a dust collecting electrode by applying an electric force to a discharge electrode, and the dust is collected by a spray from above. In wet-type electrostatic precipitators that clean the poles,
The range that the spray reaches and the whole range
A plurality of discharge electrodes divided so as to respectively correspond to other ranges provided so as to occupy a wide range, and a voltage / current is independently applied to each of the plurality of discharge electrodes. And a power supply device for applying the voltage.

[0012]

According to such a configuration, the droplet sprayed from the nozzle is charged by the voltage and current applied to the upper discharge electrode, and is immediately charged by the electric field generated between the electrodes. Move to and adhere.

Above the dust collecting electrode where the droplets adhere, the falling liquid film is disturbed, and sparks are frequently generated from the upper discharge electrode. To reach. For this reason, the falling liquid film in the lower dust collecting zone has no unevenness and is uniform, and the lower discharging electrode charged by a power source different from the upper discharging electrode has a high voltage and a high current. Application becomes possible.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a wet type electrostatic precipitator according to the present embodiment. As shown in FIG. 1, the wet-type electrostatic precipitator of the present embodiment is configured such that an upper discharge electrode 10 and a lower discharge electrode 12 are provided between dust collection electrodes 14 by using narrow spacing, thereby forming a dust collection space. Has formed. A processing gas containing dust and mist is supplied to the dust collecting space. The upper discharge electrode 10 is connected to the through insulators 18a, 18b and the support insulators 20a, 20b from the DC high-voltage power supplies 16a, 16b, respectively.
Voltage and current are applied via b. Further, a voltage and a current are applied to the lower discharge electrode 12 from the DC high-voltage power supply devices 22a and 22b through the penetrating insulators 24a and 24b and the supporting insulators 26a and 26b.

The upper discharge electrode 10 is shorter than the lower discharge electrode 12, and is provided above the lower discharge electrode 12. Further, above the upper discharge electrode 10,
A plurality of nozzles 28 for spraying droplets (spray spray) are provided. A hopper 30 is provided below the lower discharge electrode 12 for receiving dust and mist washed away by spraying. In the direction of washing away by spraying (washing direction), the nozzle 28 side is directed upward,
The hopper 30 side is downward.

Next, the operation and effect of the embodiment will be described. High voltage and high current are applied to the upper discharge electrode 10 by DC high voltage power supplies 16a and 16b, and the DC high voltage power supplies 22a and 22b are applied to the lower discharge electrode 12.
To apply high voltage and high current. As a result, a corona current flows between the upper discharge electrode 10 and the lower discharge electrode 12 and the dust collection electrode 14.

[0017] in the dust collecting space of the wet electrostatic precipitator, the process gas is supplied, including particulate matter of dust and mist and the like. Particles such as dust and mist guided to the dust collection space are charged by corona current flowing between the electrodes,
Coulomb force generated by an electric field generated between the two electrodes moves to the dust collecting electrode 14 side and is collected.

The particulate matter such as dust and mist collected by the dust collecting electrode 14 is washed off onto the hopper 30 by water sprayed from a nozzle 28 provided above the upper electrode 10, that is, spray spray.

When the spray droplets from the upper nozzle 28 reach the dust collecting electrode 14, the droplets are rebounded at the upper portion due to the collected dust and the like as shown in FIG. And irregularities such as unevenness of the falling liquid film. Therefore, sparks frequently occur in the upper electrode 10 at a low voltage.

The spray droplets from the nozzle 28 are charged by the voltage and current applied to the upper discharge electrode 10 and immediately charged by the electric field generated between the electrodes.
Moves to the side and adheres. Since most of the spray droplets are collected by the dust collection electrode 14, almost no spray droplets are present in the lower dust collection zone facing the vicinity of the lower discharge electrode 12, As a result, a stable and uniform falling liquid film is formed, so that generation of sparks can be suppressed.

For the lower discharge electrode 12, a DC high voltage power supply 16 for applying a voltage and a current to the upper discharge electrode 10.
Since the voltage can be applied by the DC high-voltage power supply devices 22a and 22b different from the devices a and 16b, a high voltage and a high current can be applied.

Since the upper discharge electrode 10 is shorter than the lower discharge electrode 12, the proportion of the entire zone where sparks are generated and sufficient performance cannot be obtained is small.
Further, in the lower dust collecting zone occupying a wide range in the whole, high voltage and high current can be applied, so that the performance is greatly improved.

In the above embodiment, the discharge electrode is described as having two stages of the upper discharge electrode 10 and the lower discharge electrode 12. However, the discharge electrode is not limited to the upper and lower two stages, but may be formed of three or more stages. You can also. In this case, a DC high-voltage power supply corresponding to the discharge electrode of each stage is provided, and a voltage and a current are applied to the discharge electrode for each stage.

In this manner, the discharge electrode is connected to the upper side discharge electrode 1.
The upper and lower discharge electrodes 12 are divided into two upper and lower stages, and the spray droplets sprayed from the nozzle 28 immediately reach the dust collection electrode 14 by the electric force applied to the upper discharge electrode 10. For this reason, the rebound generated when the spray droplets reach the dust collecting electrode 14 is formed in a uniform falling liquid film on the upper stage discharge electrode 10 side, so that in the dust collection zone on the lower stage discharge electrode 12 side. The generation of sparks caused by the unevenness of the falling liquid film is suppressed. The lower discharge electrode 12 is a DC high-voltage power supply device 22a, 22b different from the upper discharge electrode 10.
, It is possible to apply a high voltage and a high current, and to improve the performance of the entire dust collector,
As a result, the wet dust collector can be made more compact and cost can be reduced.

[0025]

As described above in detail, according to the present invention, the discharge electrode is divided into a plurality of stages, and is applied to each stage of the discharge electrode. Since the falling liquid film due to the spray droplets becomes uniform and the generation of sparks is suppressed, it is possible to apply a high voltage and a high current to the electrodes to improve the performance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a wet electric precipitator according to one embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a conventional wet-type electrostatic precipitator.

FIG. 3 is a view for explaining a state of a spray sprayed from a nozzle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Upper discharge electrode 12 Lower discharge electrode 14 Dust collection electrode 16a, 16b, 22a, 22b DC high voltage power supply 18a, 18b, 24a, 24b Penetration insulator 20a, 20b, 26a, 26b Support insulator 28 Nozzle 30 Hopper

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shoichi Onishi 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Inside Mitsubishi Heavy Industries, Ltd. Kobe Shipyard (56) References JP-A-5-23614 (JP) JP-A-58-189053 (JP, A) JP-A-53-118180 (JP, U) JP-A-62-164951 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B03C 3/00-3/88

Claims (1)

(57) [Claims] 1. A wet type electric collector in which particulate matter present in a dust collecting space is collected by a dust collecting electrode by applying an electric force to a discharge electrode, and the dust collecting electrode is cleaned by spray spray from above. In the dust device, the range where the spray spray reaches and the whole range more than this range
A plurality of discharge electrodes divided so as to respectively correspond to other ranges provided so as to occupy a wide range, and a voltage / current is independently supplied to each of the plurality of discharge electrodes. A wet type electrostatic precipitator, comprising: a power supply device for applying voltage.