JPH0122821B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to an improvement in an electrostatic filtration device that utilizes an induced electrostatic field in an electrically insulating solvent solution.

Prior Art Prior to filing this application, the present inventor had invented a filtration device for sewage or waste water that utilizes an induced electrostatic field in an electrically insulating solvent solution. It is disclosed in Japanese Patent Publication No. 51-3941, Japanese Patent Publication No. 51-3942, Japanese Patent Publication No. 23742-1984, etc. These devices provide a tank containing an electrically insulating solvent solution with an inlet for introducing the liquid to be treated and an outlet for discharging the treated liquid. At the same time, a pair of electrodes is arranged in the solvent solution inside the tank, and a high-voltage DC voltage is applied between the electrodes, which is introduced from the inlet of the liquid to be treated. The organic substance contained in the treated liquid is dissolved in the solvent solution by the action of the electrostatic field formed by the pair of electrodes, and the floating impurities in the intermediate layer formed on the upper surface of the solvent solution layer are dissolved in the solvent solution. Floating impurities are discharged from the discharge port, and treated water of a treated liquid layer formed on the upper surface of the intermediate layer is discharged from the treated liquid outlet.

With this type of conventional electrostatic filtration device, wastewater or waste water can be treated very efficiently and treated water with low impurity content can be discharged, but it is possible to discharge treated water with low impurity content, but it is possible to discharge treated water with low impurity content. When the gas is separated in an electrostatic field and floats to the surface, the contamination of gum and solvent particles that are insoluble in both solvent and water is unavoidable. often require further secondary processing.
Note that regulations regarding the organic substance content of wastewater have become increasingly strict in recent years.

OBJECTS OF THE INVENTION An object of the present invention is to provide an electrostatic filtration device that can directly take out treated water that contains almost no impurities such as solvents or gums.

Structure and Effects of the Invention The apparatus of the present invention provides a tank containing an electrically insulating solvent solution with an inlet for introducing the liquid to be treated, and a pair of electrodes arranged in the solvent solution inside the tank. In this electrostatic filtration device in which a high DC voltage is applied between the electrodes, the side wall of the tank is made into a double wall, a pocket is formed between the inner wall and the outer wall, and the inner wall The upper edge is formed above the liquid level of the solvent solution so that floating impurities in the intermediate layer formed on the upper surface of the solvent solution layer overflow from the upper edge of the inner wall into the pocket. A vertical jamb board that is continuous in all directions is placed between the inner wall and the outside wall, and a gutter that is continuous in all directions is provided on the outside and inside of this board.

The upper end of the jama board is located above the upper edge of the inner wall, and the lower end is located at the same level as or slightly below the upper edge of the inner wall, and the gutter has an opening at the same height, The mouth is located below the upper edge of the jamb and the outer wall and above the upper edge of the inner wall.

That is, in the present invention, the presence of the bar plate prevents the solvent and gum that float up with the gas dissolved in the liquid to be processed from flowing out to the pocket side, and the gutter present inside the bar plate is The purpose is to collect clean water with no impurities in the gutter outside the jama board.

In addition, in the present invention, it is preferable that the gutter located inside the jama plate be provided near the jama plate, and it is also preferable to provide a planar porous rectifier plate inside the inner wall of the tank near the upper edge of the inner wall. . The former can completely prevent the floating impurities from flowing out to the outside of the jamb plate,
The latter makes it possible to more effectively suppress floating of impurities.

The gutter outside the jama plate may be branched to increase the amount of treated water or fresh water discharged, or a plurality of gutter may be provided.

Next, the present invention will be explained in more detail according to an example shown in the drawings.

In FIG. 1, 1 is a filtration tank, and 2 is a filtration material, an inlet for a solvent solution, which is opened at the bottom of the tank 1. 3 is an inlet for the liquid to be treated (filtered) installed at an appropriate height in the center of the bottom of the tank 1, and has an appropriate length in the front-rear direction, and has a large number of relatively small-diameter holes on its outer circumferential surface. A water regulating plate 4 having a large number of micropores is arranged above it. 5 is a solvent solution layer. A pair of electrodes consisting of an anode 6 and a cathode 7 are arranged in the solvent solution.The cathode 7 is located in the center of the tank 1 and is connected to a high voltage power source, while the anode 6 is located outside the cathode 7. It faces this cathode 7 and is grounded. More specifically, the cathode 7 has a V-shaped cross section and has a pair of left and right flat inclined outer surfaces 8 extending in the above direction, while the anode 6 is made of a suitable material that does not cause spark discharge with the cathode 7. It has a pair of left and right flat inclined surfaces 9 which are arranged at a distance from each other and face both inclined outer surfaces 8 of the cathode 7, respectively, and between the lower edges of both inclined inner surfaces 9 of the anode 6 there is a An opening larger than the liquid introduction port 3 is formed. This anode 6 is fixed to a tank lid (not shown) via an anode suspension member (not shown). Inclined inner surface 9 of anode 6 and inclined outer surface 8 of cathode 7
have an appropriate interval that does not cause spark discharge, and form a pair of left and right contact zones 10 extending in the front-rear direction between them.

The cathode 7 is connected to a high-voltage conductive wire 11 and is mechanically supported by a support tube 12 containing the conductive wire 11.

The side wall of the tank 1 is double walled, and a pocket 14 is formed between the outer wall 12 and the inner wall 13. Pocket 14 is divided at the bottom to facilitate removal of impurities accumulated inside, and tank 1
It is tapered at the four corners. A vertical jamb 15 is provided above the tank 1 between the inner wall 13 and the outer wall 12, and two gutters 16 and 17 are arranged on the inside and outside of the jamb board 15. ing. (See Figures 2 and 3).

The upper edge 18 of the inner wall 13 is the liquid level 1 of the solvent solution layer 5.
9, and the supernatant liquid of the intermediate layer 20 formed on the upper surface of the solvent solution layer 5 overflows into the pocket 14 with floating impurities having sedimentation properties, which may cause harmful effects. The friction plate 15 is attached to the inner wall 13
It extends upward from approximately the same height as the upper edge 18 of the inner wall 13 between the inner wall 13 and the outer wall 12, and prevents the gum and solvent that floated up with the gas from overflowing into the pocket 14. , the processed liquid layer, that is, the water layer 21 inside the jam plate 15 is regulated to rise.

The gutters 16 and 17 are formed to have respective openings or upper edges at the same height above the upper edge 18 of the inner wall 13 and below the upper end 22 of the jam plate 15 and the upper end 23 of the outer wall 12. This gutter 1
6 and 17 regulate the liquid level of the processing solution.
Floating impurities that have risen in the water layer 21 along with the treated liquid flow into the gutter 17 inside the jam plate 15. The treated liquid discharged from the gutter 17 may be sent to the electrostatic filter again for treatment. Since only the supernatant liquid of the treated liquid overflowing into the pocket 14 flows into the gutter 16 on the outside of the jamb plate 15, the treated liquid discharged from the gutter 16 is almost pure water and can be directly drained. , it can also be used as industrial water.

A planar porous rectifier plate 24 is present near the upper edge 18 of the inner wall 13 inside the tank 1, thereby restricting the rise of floating impurities in the intermediate layer 20 and enhancing the treatment effect.

Next, a method for electrostatic treatment of factory waste liquid using the above device will be briefly explained.

First, a solvent that is electrically insulating or dielectric and has a higher specific gravity than water, such as perchlorethylene, flows into the filtration tank 1 from the inlet 2, and the liquid level 19 is maintained at a constant level.
Fill it up to.

Next, a negative DC high voltage is applied to the cathode 7. Note that in the present invention, the inner electrode can be used as an anode and the outer electrode can be used as a cathode. In this case, the electrode 7 is an anode, and a DC plus high voltage is applied thereto.

Having been prepared in this way, the liquid to be treated, preferably the liquid to be treated which has been mixed with the solvent filled in the tank 1, ie, perchlorethylene, and formed into an emulsion, is introduced into the tank 1 through the inlet 3. The speed of the liquid to be treated that is introduced into the inlet 3 rapidly decreases, and the liquid is turned into small droplets by the outer peripheral surface of the inlet 3, which has many small diameter holes, and is further formed into small droplets by drilling many micro holes above it. Due to the gently mountain-shaped water regulating plate provided, the droplets become smaller and move toward the center of the cathode 7, rising due to the difference in specific gravity.

The negatively charged droplets that are in contact with the slope 8 of the cathode 7 are attracted toward the anode 8 at high speed by the action of the electrostatic field, and the droplets that reach the anode slope 9 are now positively charged and return to the cathode 7. scatter towards. While the droplets fly back and forth between the poles 6 and 7, the oil contained in the liquid to be treated is dissolved in the solvent solution 5, solids and other impurities are also separated from the water, and the liquid rises at a slow speed. ,
Solids and other suspended impurities form an intermediate layer 20, and moisture forms an aqueous layer 21 above it.

A porous rectifying plate 24 is present on the upper surface of the intermediate layer 20, which suppresses impurities from rising into the water layer 21.
Pocket 14 efficiently without causing turbulence
overflowing to. Furthermore, even if impurities such as solvent fine particles float through the porous rectifying plate 24, they will be absorbed by the water layer 25 outside the strain plate 15 due to the presence of the strain plate 15.
It flows into the inner gutter 17 without flowing out to the inside, and is taken out from the outlet 26.

Because the liquid to be treated overflowing from the upper edge 18 of the inner wall 13 into the pocket 14 does not spread laterally due to the presence of the baffle plate 15, it flows somewhat downward along the outer surface of the inner wall 13. , floating impurities contained in the liquid to be treated are efficiently settled inside the pocket 14, water is separated into an upper layer in a pure state, and a water layer 25 is formed between the outer wall 12 and the jam plate 15 as a clean supernatant liquid. Form. Water in the water layer 25 flows into the gutter 16 and is taken out from the outlet 27.

The treated liquid taken out from the outlet 26 through the inner gutter 17 is reprocessed by being introduced into an electrostatic filtration device again to remove impurities such as solvents, but it is taken out from the outlet 27 through the outer gutter 16. The water layer extracted from the water layer contains almost no impurities, so there is no problem in draining it as is, and it can be directly reused as industrial water.

Incidentally, since the pocket 14 is formed with a tapered end, the impurities stored in the pocket 14 are quickly sedimented and concentrated, and are taken out from the outlet 28 at the lower end of the pocket 14. Furthermore, in the device of the present invention, the inner surface of the inner wall 13 of the tank 1 and the surface of the electrode suspension member are made of an insulating material such as polyvinyl chloride or Teflon, thereby further enhancing the electrostatic filtration effect. be able to.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of the device of the present invention, FIG. 2 is a side view of the device shown in FIG. 1, and FIG. 3 is a plan view showing the device shown in FIG. 1 with the porous rectifying plate removed. It is. 1...tank, 6...anode, 7...cathode, 12
... Outer wall, 13... Inner wall, 14... Pocket, 15... Jama board, 16, 17... Gutter, 21,
25...Water layer, 24...Porous current plate.

Claims (1)

[Scope of Claims] 1. A tank containing an electrically insulating solvent solution is provided with an inlet for introducing the liquid to be treated, a pair of electrodes is arranged in the solvent solution inside the tank, and a pair of electrodes is arranged between the electrodes. In an electrostatic filtration device that applies a high DC voltage, the side wall of the tank is made into a double wall, a pocket is formed between the inner wall and the outer wall, and the upper edge of the inner wall is a double wall. The intermediate layer is formed above the melting surface of the solvent solution so that floating impurities in the intermediate layer formed on the upper surface of the solvent solution layer overflow from the upper edge of the inner wall to the pocket, and the inner wall There is a vertical jama board that is continuous on all four sides between the and outer wall, and the upper end of this jama board is located above the upper edge of the inner wall, and the lower end is the same as or slightly lower than the upper edge of the inner wall. It is located below, and there are continuous gutters in all four directions on the outside and inside of the jama board, and the mouths of these gutters are at the same height, and the gutter is located below the top of the jama board and the outer wall. An electrostatic filtration device characterized by being located above the upper edge of the inner wall. 2. Claim 1, in which a planar porous rectifying plate is provided inside the inner wall near the upper edge of the inner wall.
Apparatus described in section. 3 Claim 1 in which the outer gutter is branched
The device according to paragraph 2 or paragraph 2. 4. The device according to any one of claims 1 to 3, wherein the pocket is divided at the bottom and tapered at the end. 5. Claims 1 to 5, wherein the inner surface of the inner wall and the surface of the electrode suspension member are formed of an insulating material.
The device according to any of paragraph 4.