JPS6322860B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a smoke removal device, and more particularly to a device for removing dense dust such as smoke by electrostatic precipitation.

Conventionally, thin wire electrodes as shown in Fig. 1 and fishbone-shaped electrodes as shown in Fig. 2 have been often used as discharge electrodes in electrostatic precipitators, but these electrodes do not absorb ion wind caused by corona discharge. Because air is blown out from the electrode in all directions, the air supplied to the vicinity of the electrode, which has become a negative pressure, and the ionized wind interact to create a violent turbulent flow, resulting in thick dust like smoke. When dust is collected, the discharge electrode becomes contaminated in a short period of time, resulting in a reduction in dust collection performance.

Discharge electrodes such as needle-shaped electrodes and blade-shaped electrodes that discharge with a protruding end in one direction have directional discharge, so when installed in a cylindrical electrode with the protruding end facing the inflow side of the flow path, it is difficult to concentrate. Although most of the dirt on the dust electrode can be eliminated, it has the disadvantage of increasing air resistance in the flow path due to its directivity.

In an electrostatic precipitator, there is a method of giving directionality to the ion wind of corona discharge and using it as a blowing means, but this method has the disadvantage that the discharge electrode becomes dirty, and when the discharge voltage is increased to increase the wind speed, ozone accompanying the corona discharge is generated. The disadvantage was that the occurrence of

SUMMARY OF THE INVENTION The present invention aims to eliminate the above-mentioned drawbacks of conventional devices and provide a smoke removal device that does not contaminate discharge electrodes, has high dust collection properties, has low ozone, and does not require air blowing means. .

Next, details of the present invention will be specifically explained based on Examples.

FIG. 8 is a sectional view of a smoke removal device which is an embodiment of the present invention.

In the figure, a plurality of corona discharge electrodes 4 that discharge with protruding ends 12 in one direction are provided in series inside a cylindrical electrode 1 that forms a flow path 2 and has a passage cross-sectional area that is large on the inflow side and small on the outflow side. These are sequentially called the first discharge electrode, the second discharge electrode, the third discharge electrode, etc. from the inflow side of the flow path.
The discharge electrode is arranged with its protruding end 12 facing the inflow side of the flow path, and the other discharge electrodes following this are all arranged with their protruding ends 12 facing the outflow side.

The cylindrical electrode 1 may be cylindrical or prismatic, but when it is a cylindrical electrode, the discharge electrode 4 is a needle-like discharge electrode as shown in FIG. As shown in the drawings, FIGS. 8 and 9, the electrode is a blade-shaped discharge electrode that discharges from one edge in one direction.

The distance l between the first discharge electrode and the second discharge electrode satisfies l> _r1 + _r2 , where _r1 and _r2 are the distances from the respective discharge electrodes to the inner surface of the cylindrical electrode.

Now, when a high voltage is applied between the discharge electrode 4 and the electrode 1 by a high voltage power source (not shown) in this device, corona discharge occurs at each protruding end 12 of the discharge electrode 4, and the corona ions are dispersed in an ion wind. Air is emitted to the front side of each protruding end 12, and air is radiated along the side of the discharge electrode 4 from the rear where the ion wind is not blown out to the protruding end 12, which has become a negative pressure due to the ion wind being blown out. Supplied.

In this way, a steady flow of undisturbed ion wind is generated at each discharge electrode, but since many of the discharge electrodes face the outflow side of the flow path, the airflow as a whole flows toward the outflow side where the passage cross section is small. Become,
The current is added each time the number of discharge electrodes increases.

When dust-containing air is supplied from the opening 5 on the inflow side under such a situation, the dust-containing air is pressed against the inner surface of the cylindrical electrode 1 by the steady flow of the ion wind described above and flows through the flow path 2 on the outflow side. During this period, the dust charged by the corona ions immediately reaches the electrode 1.
The cleaned air collected on the surface is discharged to the outside through the opening on the outflow side.

In the present invention, the airflow in the flow path is sequentially accelerated by a plurality of discharge electrodes with their protruding ends facing the outflow side of the flow path, so the flow velocity and air volume are large. Because there is no need to increase the discharge voltage, less ozone is generated.

Further, in the present invention, since the cylindrical electrode 1 has a large passage cross-sectional area on the inflow side of the flow path, the flow velocity of the flow path is reduced on the inflow side of the flow path.
Therefore, even if it is accelerated in the latter stage, the flow velocity of the dust-containing air is slow in the part of the first discharge electrode located on the inflow side of the flow path, and most of the dust is collected in this part, so that the dust does not pass through this part. The first discharge electrode and the second discharge electrode, which receive air supply to the protruding end 12 from the air, are hardly contaminated.

Furthermore, in the present invention, since the passage cross-sectional area of the cylindrical electrode 1 becomes smaller on the outflow side of the flow path, the electric field between the discharge electrode 4 and the electrode 1 becomes stronger as it goes toward the outflow side of the flow path. Even difficult-to-clean dust can be sufficiently collected, and the present invention has extremely excellent dust collection performance.

Further, in the present invention, since the passage cross-sectional area of the flow path is large in the portion of the first discharge electrode facing the inflow side of the flow path, the air resistance due to the ion wind of the first discharge electrode is also small.

Next, in the device of the present invention, the electrode 1 is arranged such that the diameter of the inflow side opening is 30 mm and the diameter of the outflow side opening is 18 mm.
A dust removal test using cigarette smoke with an applied voltage of 6KV using 3 mm cylindrical electrodes and 3 needle discharge electrodes facing the outflow side of the flow path resulted in a dust removal test of 99.98 mm.
% dust collection rate, and the discharge electrode was hardly contaminated even during long-term operation.

On the other hand, when a similar test was conducted using Electrode 1 as a right cylinder with a diameter of 18 mm, the dust collection rate was 98.5%, and a slight amount of dirt was observed on the discharge electrode during the same period of operation as in the former case.

In addition, the flow velocity at the outlet opening in the former is 1.3 m/s and the ozone concentration is 0.015 ppM, which is a considerably lower value than 0.2 ppM in the conventional device.

As described above, the present invention eliminates the drawbacks of conventional devices and provides a smoke removal device that does not contaminate discharge electrodes, has high dust collection properties, has low ozone, and does not require an air blower. .

[Brief explanation of the drawing]

1, 2, 3, and 4 are diagrams for explaining the present invention, and FIG. 5 is a perspective view of FIG. 4. 6 and 7 are a cross-sectional view and a perspective view thereof, respectively, for reference of the present invention, and FIGS.
The figure shows one embodiment of the discharge electrode of the present invention. 10th
The figure is a sectional view of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Electrode plate, 2... Cylindrical channel, 3... Electrode holding member, 4... Corona discharge electrode, 5... Inflow side open end, 6... Outflow side open end, 7... Contaminated air flow ,
8...Corona shower, 9...Corona electrode (thin wire shape), 10...Corona electrode (fish bone shape), 11...Clean air flow, 12...Protruding end, 13...Substrate, 14
. . . Broken thin wire, 15 . . . Electrode fitting, 16 . . . Portion not exposed to corona shower radiation, 17 .

Claims (1)

[Claims] 1 A plurality of corona discharge electrodes that discharge only at the protruding end in one direction are provided in series inside a cylindrical electrode that forms a flow path and has a passage cross-sectional area that is large on the inflow side and small on the outflow side. From the inflow side of the path, the first discharge electrode, the second discharge electrode...
An n-th (n is a positive integer greater than 2) discharge electrode,
The first discharge electrode is arranged with its protruding end facing the inflow side of the flow path, and the other discharge electrodes following it are arranged with their protruding ends facing the outflow side of the flow path. Smoke removal device.