JPS5917392Y2 - electrostatic precipitator - Google Patents

Description

[Detailed Description of the Invention] Generally, the frequency of electrode hammering in an electrostatic precipitator is determined depending on the amount of dust contained in the gas to be treated.

However, for example, the final dust collection chamber should be hammered once every hour.
In the case of a hammering frequency of 59 minutes, that is, hammering is stopped for 59 minutes and the total dust collecting electrode is hammered once for 1 minute, the treated gas dust content at the outlet is is 5mg/Nm3
However, the amount increases significantly to 30 to 40 mg/Nm3 for 1 minute during hammering.

This is because the collected dust is scattered again by hammering and is discharged together with the gas.

In order to suppress the high dust concentration during this hammering, an electrostatic precipitator is installed in multiple dust collection chambers 7 and 7 as shown in FIG. 8. When hammering the dust collecting electrode, the dampers 10 and 11 at the entrance and exit of the hammering dust collecting chamber 7 are closed, and the high voltage charging of the dust collecting chamber is also stopped, and then the chamber is closed. Conventionally, a method of hammering the dust collection pole has been adopted, but this method requires a dust collection area equal to one division of the thread than the required dust collection surface, which is not economical.

Furthermore, in order to divide the electrostatic precipitator into classrooms, extra rectifiers and entrance/exit dampers are required, and a partition plate for dividing the electrostatic precipitator casing is required, resulting in an expensive device.

In addition, the gas flow inside the electrostatic precipitator may be disturbed by the opening and closing of the damper, impeding the dust collection effect, and when the damper is opened and closed, dust deposited on the duct surface near the damper may be dispersed into the gas by the high-speed flow. There are drawbacks.

The present invention solves these drawbacks and provides a new electrostatic precipitator that reduces the amount of dust re-splattered during hammering.

FIGS. 2 and 3 show an embodiment of the present invention.

As shown in the figure, the dust collector of the present invention includes a discharge electrode, a vertical plate-shaped dust collection electrode (dust collection plate) 2, and a hammering device (hammer) 3 for the dust collection electrode 2. The dust collection chamber 21, the outlet hood 6 connected to the exit side of the dust collection chamber 21, and the outlet hood 6 are installed movably in the hood width direction (in the direction of the arrow in FIG. 3), A movable medium hood 1 that can take a downstream position of the dust collection electrode to be hammered, a duct 22 that communicates the small hood 1 with the upstream side of the dust collection chamber 21, and a dust collection downstream side installed in the duct 22. A blower (fan) 4 blows air from the side to the upstream side.

Therefore, the movable middle hood 1 opens toward the upstream side,
The width a of the opening is at least twice the distance between the dust collecting electrodes 2.

That is, the movable small hood 1 is linked with the hammering device so that it always moves to the rear position of the dust collecting plate 2 in the row where the hammer 3 for the dust collecting electrode hammers, and the hammering device is The re-dispersed dust generated by hammering does not flow out other than the dust collection plate.
All of them are configured to be sucked into a small movable hood by a fan 4 and returned to an upstream duct 5 of the electrostatic precipitator.

Therefore, the returned scattered dust is recaptured by the electrostatic precipitator, and high-concentration exhaust gas is not released into the atmosphere from the chimney.

In the present invention, the width a of the opening of the movable small hood 1 is at least twice the distance between the dust collection electrodes 2, and by setting it to such a width, the passages on both sides of the dust collection plate to be hammered are Since the width is such that it completely covers the dust collection plate, it is possible to suction the entire amount of dust that is about to get on and off the dust collection plate and flow down, and it is possible to completely prevent re-scattering.

Furthermore, the amount of gas to be sucked is extremely small, as it is sufficient to suck only the gas flowing through the passage in contact with the dust collecting plate to be hammered.

In the case of a large electrostatic precipitator, the number of passages is about 100. Therefore, the opening width a of the small movable hood 1 is equal to the distance between the dust collecting electrodes.
Even if the gas volume for two passages is returned to the electrostatic precipitator side, the processing air volume increases by 2%, so the effect on the electrostatic precipitator performance is negligible compared to the conventional method. It is.

In addition, the extra dust collection area that should be added in the design can be reduced.
Further, there are advantages such as no need for complicated damper control.

The vertical dimension of the mobile small hood is determined by taking into account the properties of the collected dust and the structure of the electrostatic precipitator, but generally the length that covers the entire length of the dust collection electrode is not necessary; It is sufficient to cover the entire area.

This is because the dust collected on the dust collection pole is re-dispersed by hammering, and the settling speed is fast, and the dust at the bottom of the dust collection pole falls almost directly below.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a conventional electrostatic precipitator, FIG. 2 is a side view of an electrostatic precipitator according to the present invention, and FIG. 3 is a plan view of the electrostatic precipitator shown in FIG. Incidentally, the symbols of the main parts in the figure are as follows. 1...Movable small hood, 2...Dust collection plate, 3...Punching hammer, 4...Fan,
5... Upstream duct, 6... Outlet hood, 7... Dust collection chamber, 8... Dust collection chamber, 9...
...Dust collection chamber, 10...Damper, 11...
...Damper, 21...Dust collection chamber, 22...
···duct.

Claims (1)

[Scope of utility model registration request] A dust collection chamber in which a discharge electrode, a vertical plate-shaped dust collection electrode, and a hammering device for the dust collection electrode are installed; an outlet hood connected to the exit side of the dust collection chamber; and the exit hood. A movable medium hood, which is movable in the hood width direction and can be positioned downstream of the dust collection electrode to be hammered, communicates with the small hood on the upstream side of the dust collection chamber. duct, and a blower installed in the duct to blow air from the downstream side to the upstream side of the dust collection chamber, the movable middle hood opens toward the upstream side, and the width of the opening is as described above. An electrostatic precipitator characterized in that the spacing is at least twice the spacing between dust collecting electrodes.