JPH079443U - Dielectric filter - Google Patents

Abstract

(57) [Abstract] [Purpose] A filter medium is impregnated with highly insulating oil, and a high-voltage electrode and a ground electrode are attached to the filter medium to provide a high capture rate as a dielectric filter and a long service life as a wet filter. Let [Structure] The dielectric filter 1 is provided with a high-voltage electrode 3 on the front surface side of a sheet-shaped filter medium 2 and a ground electrode 4 on the back surface side, and is charged by a high-voltage generator 5. Filter medium 2 is oil 6 with high insulation
Is impregnated with. Therefore, it has both dielectric and wet characteristics. Further, an oil repellent layer may be formed on the back side of the filter medium to prevent the oil from being carried away, or the filter medium may be impregnated with a resin mixed with a flame retardant in advance to impart flame retardancy.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to a dielectric filter.

[0002]

[Prior art]

 Dielectric filters are known to have a higher dust trapping efficiency than other general filters. A natural fiber, an artificial fiber, or a mixture of these was used as the filter medium of this filter, which was a so-called dry type filter medium.

[0003]

[Problems to be solved by the device]

 The conventional dielectric filter has a high dust trapping efficiency and therefore traps fine dust, which is a drawback that it is quickly clogged. In addition, in order to provide flame retardancy, some filter media have been made flame-retardant, but with conventional flame-retardant means, the insulating property of the filter decreases as described below, so high capture efficiency as a dielectric type cannot be maintained. There is a problem.

[0004]

[Means for Solving the Problems]

 According to the invention of claim 1, the filter medium is impregnated with highly insulating oil.

According to a second aspect of the invention, an oil repellent layer formed by coating a resin having a high oil repellent property is formed on the back surface side (the fluid advancing side) of the filter medium of the first aspect.

According to a third aspect of the invention, the filter medium is impregnated with a resin mixed with a flame retardant, and further impregnated with silicone oil having a high insulating property.

In each of the filter media of claims 1, 2 and 3, a high voltage electrode is provided on one side of the front or back side of the filter medium and a ground electrode is provided on the other side of the filter medium to charge a high voltage to form a dielectric filter.

[0008]

The dielectric filter according to claim 1 functions as a so-called wet filter medium because the fiber of the filter medium is covered with oil having a high insulating property, and the filter can be used like a normal mineral oil having a low insulating property. It does not neutralize the charge and lower the dielectric function. Therefore, while maintaining a high capture rate as a dielectric type, the fine dust that is about to pass through is trapped by the oil as a wet filter medium, agglomerates and coarsens to form a cake layer, which causes a filtering action, so a large amount of dust is generated. While catching, clogging increases the life.

According to a second aspect of the present invention, a filter medium layer coated with a highly oil-repellent resin is formed on the back side of the filter medium of the first aspect, and the oil impregnated in the filter medium is carried away to the clean side by the passage of air. The oil repellent layer prevents the oil from flowing out to the cleaning side such as oil mist.

According to the third aspect, since the fibers of the filter medium are flame-retardant and silicon oil having a high insulating property is used as the oil, the same high capture rate and long life as those of the first aspect can be obtained. In addition, the fire resistance of the filter is high because the silicone oil is almost incombustible.

By the way, in the conventional flame-retardant treatment, a flame retardant and a water-soluble binder (such as a vinyl chloride-based binder with self-extinguishing property) are attached to the fibers of the filter medium. Although the insulating property of the fiber is lowered and the performance of the dielectric filter is lowered, the present invention does not have this possibility.

[0012]

【Example】

 FIG. 1 shows an embodiment of claim 1. The dielectric filter 1 is provided with a linear (or a belt-shaped one is appropriately used depending on the shape of the filter material) high-voltage electrode 3 on the front surface side (front end side) of the fold-folded filter material 2, and the back surface side (rear end side). A ground electrode 4 is provided on the ground and charged by a high voltage generator 5.

The filter medium 2 is made of an appropriate natural or artificial sheet-like filter medium and is impregnated with an oil 6 having a high insulating property (for example, silicon oil having a high insulating property). Therefore, the oil itself becomes a wet filter while maintaining the characteristics of the dielectric filter, resulting in high trapping efficiency and long life.

FIG. 2 shows an embodiment of claim 2. The dielectric filter 7 comprises a filter medium 8 provided with a high voltage electrode 3, a ground electrode 4, and a high voltage generator 5 similar to those shown in FIG.

Similar to the filter medium 2, the filter medium 8 is impregnated with highly insulating silicone oil 6, and the back side is coated with a highly oil-repellent resin (generally a fluorine-based oil repellent is used as the oil repellent agent) to form an oil repellent layer. 9 are provided.

Further, as the oil-repellent layer 9, without using the back side of the filter medium 8, a separate sheet-shaped filter medium (not shown) is coated with a highly oil-repellent resin, and this is applied to the back side of the filter medium 8. The oil repellent layer 9 may be superposed on each other. The oil repellent layer 9 can prevent the oil mist from flowing out to the cleansing side and carried away together with the clean air.

FIG. 3 shows an embodiment of claim 3. The dielectric filter 10 comprises a filter medium 11 provided with a high voltage electrode 3, a ground electrode 4 and a high voltage generator 5 similar to those shown in FIG.

The filter material 11 is a sheet-shaped filter material of natural or artificial fibers, which is impregnated with a resin 12 in which a flame retardant is mixed, and is further impregnated with silicone oil 13 having a high insulating property.

Therefore, all of the dielectric filters shown in FIGS. 1, 2 and 3 have high trapping efficiency and have a long life. And the one in Fig. 2 does not carry the oil to the clean side. All of them use silicone oil, so they are flame retardant, but the one in Fig. 3 is highly flame retardant.

[0020]

[Effects of the Invention] According to the first, second, and third aspects, a long service life can be obtained as a wet filter medium while maintaining a high dielectric-type capturing efficiency. In the second aspect, oil can be prevented from being carried away to the clean side, and in the third aspect, high flame retardancy can be obtained.

[Brief description of drawings]

FIG. 1 is an embodiment of claim 1.

FIG. 2 is an embodiment of claim 2;

FIG. 3 is an embodiment of claim 3;

[Explanation of symbols]

 2, 8 and 11 Filter media 3 High voltage electrode 4 Ground electrode 5 High voltage generator 6 Insulating oil 9 Oil repellent layer 12 Silicon oil

Claims (3)

[Scope of utility model registration request] 1. A dielectric filter in which a sheet-shaped filter medium is impregnated with highly insulating oil, and a high-voltage electrode is provided on one side of the filter medium and a ground electrode is provided on the other side. 2. A sheet-shaped filter medium is impregnated with highly insulating oil, and an oil-repellent layer made of a filter medium coated with a resin having a high oil-repellent property is formed on the back side of the filter medium. A dielectric filter with a high-voltage electrode on one side and a ground electrode on the other side. 3. A sheet-shaped filter medium containing a resin mixed with a flame retardant, and further impregnated with highly insulating silicon oil, wherein the filter medium has a high-voltage electrode on either the front side or the back side and the other side. A dielectric filter with a ground electrode.