JPH037429B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic bag filter for collecting dust inevitably generated in various factories and the like.

Conventional electrostatic bag filters directly supply dust-containing gas to the cloth that constitutes the filter, so that the dust therein is trapped when it hits the cloth, and only the gas passes through the cloth.

Therefore, when dust-containing gas is continuously supplied to the surface of the cloth, a layer of dust is formed along that surface, but at this time, the dust layer is constantly pressed against the cloth due to the flow velocity of the dust-containing gas. Because the dust is coated, it tends to harden and the density of the dust increases.

For this reason, the pressure loss of the dust-containing gas that is subsequently supplied increases significantly as it passes through the fabric, and the power cost of the fan for supplying the dust-containing gas increases, making it uneconomical.

Moreover, in order to prevent this, it is necessary to frequently brush off the firmly adhered dust layer, but this operation shortens the life of the cloth.

The present invention relates to an improvement of such a conventional bag filter, and its purpose is to prevent a layer of dust contained in dust-containing gas from forming firmly on the surface of the cloth constituting the bag filter.

Another object is to reduce the pressure loss of the dust-containing gas when it passes through the cloth to which the dust layer is attached.

Another purpose is to make the dust layer attached to the cloth porous so that gas can easily pass through it.

This invention will be explained with reference to the accompanying drawings.
and connect the negative terminal 6 and positive terminal 7 of a high voltage DC power supply 5 to the linear electrode 1 and the other linear electrode 2, respectively,
Further, both ends of the double helical electrode 3 and the cylindrical cloth 4 are connected to the inlet 10A of the dust-containing gas passage 11 in the casing 10, that is, on the upstream side of the cylindrical cloth 4, through the upper insulator 8 and the lower insulator 9. An optional dust precharging device is provided, for example a precharging device 14 consisting of a needle corona discharge electrode 12 and an annular counter electrode 13.

In FIG. 1, 15 is an insulator for passing electric wires into and out of the casing 10, 16 is a tightening band for fixing the cloth 4 and the double helix electrode 3 to the upper insulator 8 and the lower insulator 9, respectively. A clean air passage, 19 a dust discharge conveyor, 20 its prime mover, 21 a dust discharge port, 22 an upper header for engaging the upper insulator 8, and 23 a number of dust penetrations for engaging the lower insulator 9. It is a lower header with a hole.

When the dust-containing gas supplied from the dust-containing gas inlet 10A passes through the pre-charging device 14, the dust contained therein is charged negatively, for example, and advances toward the outer periphery of the cylindrical cloth 4, where it is charged. Attach.

At this time, since a high DC voltage is applied to the double helix electrodes 1 and 2 by the high voltage DC power supply 5,
Arc-shaped lines of electric force 2 are formed between adjacent electrodes 1 and 2.
5 is formed, and the above-mentioned charged dust 24a is aligned in a bead shape along the lines of electric force 25 as shown in FIG. 2, forming the dust layer 24.

In the dust layer 24 in this state, each dust 24a is coarsely deposited as a whole, and the dust layer 24 becomes porous.

The gas in the dust-containing gas supplied on top of this deposited dust layer 24 then passes through this and enters the cylindrical cloth, leading from the upper outlet 26 to the clean gas passage 18 and eventually to the exhaust gas of the casing 10. It is released into the atmosphere from the outlet 10B.

Further, the dust adhering to the outer circumference of the cylindrical cloth 4 gradually accumulates to form a layer, and when the thickness of the layer reaches a certain level, the high voltage direct current connected to the double helical electrodes 1 and 2 is removed. The power source 5 is cut off by the changeover switch 27, the high voltage AC terminal 28 is connected, and an alternating electric field is generated between the double helix electrodes 1 and 2, thereby removing the dust accumulated on the surface of the cloth 4. The layer is peeled off from this, falls down, and is discharged from the outlet 21 of the casing 10 by the conveyor 19.

This invention is as described above, and as shown in FIG. The dust particles 24a are arranged like beads along the curves of the electric lines of force 25 and collide directly with the surface of the cloth 4.
will be softly attached to the surface of the cloth 4, and the layer will be formed porous. Therefore, even if a certain amount of dust layer is deposited on the cloth 4, the fluid resistance when passing through the cloth 4 does not increase so much, and the pressure loss is small.

As a result, less power is needed for the fan to feed the dust-containing gas into the device, making it extremely economical.

Further, in the present invention, since dust is collected using the electric lines of force 25 and the cloth 4, dust having a wide range of particle sizes can be efficiently collected, and the dust collection efficiency can be improved.

The use of a double helical electrode as the electrode in this case is a major feature of the present invention, which makes the electrode structure simpler than any other.

Although the present invention has been explained above based on FIGS. 1 and 2, the present invention is not limited to what is shown therein. As shown in FIG. A dust layer may be formed on the inner surface of the cloth 4 by superimposing the dust-containing gas on the inner circumferential surface and supplying the dust-containing gas outward from the inner circumferential surface.

In addition, in the figure, the parts having the same drawing symbols as in FIGS. 1 and 2 have the same functions and names.

In addition, as shown in FIG. 4, in order to maintain the distance between the linear electrodes 1 and 2 constituting the double helix electrode 3, one or both of the electrodes 1 and 2 are provided with a spherical or appropriately shaped insulator. 5, or spacers 31 made of a cylindrical insulator with double helical grooves 30 formed on the outer periphery as shown in FIG. They can also be fitted onto the surface at appropriate intervals.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a part of FIG. 1 in an operating state, and FIG. 3 is an enlarged view of another part of FIG. 1 in an operating state. cross section,
FIG. 4 is a front view of another embodiment of a part of FIG. 1;
FIG. 5 is a perspective view of another embodiment of a portion of FIG. 4. 3...Double helical electrode, 4...Cylindrical cloth,
5...DC high voltage power supply, 11...Dust-containing gas passage, 1
4... Pre-charging device, 29... Spherical insulator spacer, 30... Double spiral groove, 31... Cylindrical insulator spacer.

Claims (1)

[Claims] 1. A cylindrical cloth is polymerized along the circumferential surface of double spiral electrodes provided insulated from each other, a DC high voltage power source is connected between the double spiral electrodes, and a DC high voltage power source is connected between the double spiral electrodes. An electrostatic bag filter equipped with a pre-charging device on the upstream side of the dust-containing gas passage to the cloth. 2. The electrostatic bag filter according to claim 1, wherein the cylindrical cloth is superposed on the outer peripheral surface of the double helical electrode. 3. The electrostatic bag filter according to claim 1, wherein the cylindrical cloth is superposed on the inner peripheral surface of the double helical electrode. 4. The electrostatic bag filter according to claim 1, wherein the distance between the double helical electrodes is maintained by an insulating spacer fitted to the electrodes. 5. Claim 1, wherein the double helical electrodes are spaced apart from each other by a double helical grooved cylindrical insulating spacer fitted to the inner peripheral surface of the electrodes. The electrostatic bug filter described in .