JPH0847691A - Separator - Google Patents

Abstract

PURPOSE:To obtain a separator capable of separating an electrodeposit as a cake dehydrated to suspensoid and easy to handle with a small amt. of electric energy and high efficiency by providing the separator with an electrodeposit scraping means in contact with the surface of an electrode part in the space above the liq. surface on the upper end of the rotary electrode part formed by a discoid rotor vertical to the liq. surface. CONSTITUTION:An electric field is applied on the rotary electrode 2 and fixed electrode 5 while rotating the electrode 2, hence the suspensoid in the negatively charged liq. to be treated moves toward the electrode 2 as an anode, and the suspensoid is electrodeposited on the surface of the electrode 2. The suspensoid electrodeposited on the electrode 2 is highly hydrated in the liq. and slurried, the slurry is transferred on the liq. surface as the electrode 2 rotates, and the slurry on the electrode 2 is dehydrated and solidified to form a cake holding its shape well. The electrodeposit is sufficiently dehydrated until reaching a scraper 3 to form a cake holding its shape well, and the cake is scraped off by the scraper 3 without breaking the electrodeposit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separation device used when separating a suspended matter from a liquid to be treated by electrophoresis.

[0002]

2. Description of the Related Art An electrophoretic method may be used to separate a suspension material such as colloidal particles or solid fine particles dispersed / suspended in water from a medium. The outline of this separation method is that the interfacial electrolysis under the action of an electric field between the electrodes makes the suspending substance and the medium different polar ions, direct the suspending substance to one electrode, and the liquid medium to the other electrode And electrodeposited and deposited on one electrode surface, and the electrodeposited deposits are scraped off with a scraper and collected. Usually, the suspension is often negative ions, and the suspension is electrodeposited and deposited on the anode.

Conventionally, as this anode, the lower half of a drum-shaped electrode having a horizontal axis is immersed below the liquid surface, and while the drum-shaped electrode is rotated, a suspended substance is electrodeposited / precipitated,
It is known to scrape this electrodeposition deposit on the drum surface above the liquid surface with a scraper.

[0004]

Observing the transfer state of the electrodeposited deposits on the drum type electrode, the electrodeposited deposits on the surface of the drum type electrode in the liquid are in a slurry state with a high water content. When the drum is rotated, it is pulled up above the surface of the liquid, and dehydration progresses to approach a cake shape.

However, the above-mentioned dehydration depends on natural dehydration, and since the drum surface has a relatively gentle gradient, the rotating speed of the drum-shaped electrode must be made considerably slow depending on the kind of the suspended solid. However, dehydration becomes insufficient, the slurry state cannot be completely removed, and scraping becomes difficult, and a large amount of water content may be required for subsequent treatments, for example, incineration treatments, resulting in great cost. On the other hand, when the rotation speed of the drum-shaped electrode is set to be low, a decrease in electrodeposition / deposition efficiency cannot be avoided.

Further, in the above electrodeposition / precipitation, gas is generated on the electrode surface due to electrolysis, and when the rotation speed of the drum type electrode is slowed down, a gradient occurs on the drum surface in the lower half of the drum in the liquid. Is relatively gentle, the gas is likely to stay, and a gas layer is formed, which inevitably lowers the electrodeposition / deposition efficiency.

As described above, in the above-mentioned drum type electrode, when rotating at a high speed, it is difficult to sufficiently dehydrate the electrodeposited / precipitated suspension, and the scraping treatment of the electrodeposited deposit and the subsequent incineration treatment are performed. If it becomes difficult, or if it spins at a low speed to perform sufficient dehydration, defective degassing will also occur, resulting in high efficiency electrodeposition.
It is difficult to guarantee precipitation, energy consumption increases, and it is not easy to satisfy both high dehydration and low energy consumption. Further, in the above-mentioned drum type electrode, the electrode area per unit volume is small due to the structure, and the treatment efficiency is low.

The object of the present invention is to solve the above-mentioned problems of the prior art. When separating a suspended matter from a liquid to be treated by an electrophoresis method, the suspended matter is dehydrated. An easy cake is to provide a compact separation device capable of separating with low power consumption and high processing efficiency.

[0009]

In the separation apparatus of the present invention, the suspension and the medium of the liquid to be treated are moved in opposite directions by electrophoresis, and the suspension is electrodeposited / precipitated on one electrode. An apparatus for separating suspended solids by arranging one or more disc-shaped rotating bodies perpendicular to the liquid surface, and forming one of the electrodes by the rotating body as a rotating electrode, and the other. The electrode of No. 3 is arranged in parallel with the rotating electrode to form a fixed electrode, and a means for scraping electrodeposited deposits is provided in contact with the surface of the electrode portion in the space above the liquid surface at the upper end of the rotating electrode portion. This is a characteristic configuration. Preferably, the fixed electrode is parallel to the rotating electrode,
A total of two sheets are provided, one on each side of each rotary electrode, and more preferably, a scraper is used as a scraping means for scraping electrodeposits, and the scraper has a substantially insulating structure. is there.

[0010]

Since the electrode portion on the liquid surface is vertical to the liquid surface, the electrodeposited deposits on the electrode surface rise to the liquid surface as the disc-shaped rotating electrode rotates, Drains well and can be dehydrated efficiently. Further, even if gas is generated from the electrode surface by electrolysis in liquid, the electrode portion below the liquid surface is also a vertical surface, so that the gas can be quickly floated and gas can be quickly degassed, Further, because of the structure, the electrode area per unit volume is large, so energy-saving and space-saving high-efficiency electrodeposition / deposition can be guaranteed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments of the present invention. 1 and 2 are explanatory views showing an example of a separation device used in an embodiment of the present invention. In FIG. 1, 1 is a liquid to be treated (colloidal particles, solid fine particles, oil, etc. dispersed,
It is a tank that receives suspended water). Reference numeral 2 is a rotary electrode (anode), 3 is a scraper, 4 is a drive motor for rotating the rotary electrode 2, 5 is a fixed electrode (cathode), 6 is a supply port for a liquid to be treated, 7 is a treatment liquid outlet, and 8 is It is a shoot.

Since one end of the fixed electrode 5 is fixed to the wall surface of the tank 1 for receiving the liquid to be treated by welding or the like and the other end is provided at a certain distance from the wall surface of the tank 1 for receiving the liquid to be treated, As shown in FIG. 2, the liquid to be treated is supplied through the supply port 6
After being received from S., an S-shaped flow is formed and passes between all electrodes, so that the separation is efficiently performed by electrophoresis.

In FIGS. 1 and 2, a disc-shaped rotating electrode 2 is provided.
When an electric field is applied to the rotating electrode 2 and the fixed electrode 5 while rotating, the suspended matter in the liquid to be treated, which is normally negatively charged, moves toward the rotating electrode 2 which is an anode, and the surface of the rotating electrode 2 Suspended matter is electrodeposited and deposited on top. In this case, since the electrolysis of water occurs at the same time, gas is generated on the surface of the rotary electrode 2, but since the surface of the rotary electrode 2 is vertical, the generated gas quickly floats, and there is no gas retention and high efficiency. The electrodeposition / precipitation of suspended matter can be guaranteed.

The suspension material electrodeposited and deposited on the rotary electrode 2 has a high water content in the liquid and is in the form of a slurry. When this slurry is transferred onto the liquid surface as the rotating electrode 2 rotates, the slurry on the surface of the rotating electrode 2 is dehydrated and solidifies into a cake with good shape retention.

In this case, since the surface of the rotating electrode 2 is a vertical surface, the draining property is good, the dehydration proceeds at a high speed, and the dehydration is sufficiently advanced by the time the electrodeposits reach the scraper 3 and are solid. It is easy to reach a cake state with good shape retention. Therefore, the scraper 3 can scrape the electrodeposition deposit without breaking it, and the scraped product can be easily transported. In addition, since the amount of dehydration is sufficient, the amount will be small, so that it is possible to reduce the collection price of the industrial waste treatment company. Alternatively, in the case of incineration, since the water content is low, incineration is easy and the energy cost can be kept low.

In the case where the scraper 3 is attached to a structure having the same pole as the fixed electrode 5 as in this embodiment,
The scraper 3 is made of a material having a substantially insulating property. When the scraper 3 has the same pole as the rotating electrode 2 due to the mounting structure of the scraper 3, the scraper 3 may be made of a material having substantial conductivity. The disk-shaped rotary electrode 2 in which the electrodeposited deposits are removed by the scraper 3 and the surface has been restored to the original good electrodeposition property, further penetrates into the liquid from above the liquid surface, and electrodeposition / precipitation is performed again. repeat.

In order to improve the dehydration property of electrodeposition / precipitation in the above, it is desirable that the rotation speed of the rotary electrode 2 be 10 revolutions per minute or less.

In the above, the distance between the anode 2 and the cathode 5 is set in accordance with the size of the apparatus, the concentration of suspended solids in the liquid, the electrical conductivity, the generation of floating precipitates, the appropriate current density and voltage, and the like. It is desirable to have a structure in which the distance can be adjusted.

In the above, a non-electrolytic material is suitable for the rotary electrode 2, for example, platinum-plated stainless steel, titanium sheet or carbon material is used.
In order to prevent excessive precipitation due to the tip effect, it is preferable to provide an insulating coating on the edge or round the acute angle to relax the electrolytic field.

In the above description, the case where the suspended matter is negatively charged has been described. However, the suspended matter may be positively charged. In this case, the rotary electrode 2 is the cathode and the fixed electrode 5 is It is used as an anode.

The separating apparatus of the present invention separates and collects suspended solids such as colloidal particles and solid fine particles that are dispersed and suspended in water from a medium, and also separates and recovers oil from an emulsion in which oil is dispersed. Can also be used for When the separation device of the present invention is used, colloidal particles, solid fine particles or wastewater in which oil is dispersed / suspended, colloidal particles, solid fine particles in a cake state having a low water content, or at a high oil content, and It can be separated and collected with low power consumption. This is also clear from the operation results of the following examples.

Example 1 In FIG. 1, the rotating electrode (anode) 2 has a diameter of 260 mm.
Using 4 platinum-plated discs of stainless steel,
The rotation speed of the rotary electrode 2 by the drive motor 4 can be adjusted up to 10 rotations per minute, and is set to 2 rotations per minute. Scraper 3
The material of the is an insulative rubber, which is a fluororubber excellent in oil resistance. Stainless steel is used for the fixed electrode (cathode) 5, and the distance between the rotating electrode (anode) 2 and the fixed electrode (cathode) 5 is adjustable in the range of 3 mm to 30 mm, and is 10 mm.
Adjusted to. The maximum DC voltage applied between both poles is 100.
It is possible to adjust up to V and set it to 60V. The liquid to be treated was degreasing and cleaning drainage of metal parts with an oil concentration of 5.2 voL% (using Axalel 32 manufactured by Mitsui DuPont Fluorochemicals as the cleaning agent), and the treatment liquid was supplied at a flow rate of 50 L / hr. At the treatment liquid outlet 7, the treatment liquid having an oil concentration of 0.42 voL% was 47.6 L / hr, and the oil content of almost 100 voL% was 2.4.
L / hr was obtained. The separation efficiency based on [Equation 1] at this time is 9
It was 1.9%. [Equation 1] Separation efficiency = [1- (treatment liquid concentration / supply liquid concentration)] × 100 (%) The power consumption was 0.76 kwh per 1 kg of 100% oil. The power consumption is less than half as compared with the conventional method.

[0023]

EFFECT OF THE INVENTION The separation device of the present invention is configured as described above, and has a high water treatment efficiency, low power consumption, and a low water content in which suspended solids can be easily handled by electrophoresis from a suspension feeder. 4 can be collected while maintaining a sufficient electrodeposition / precipitation rate,
It is extremely useful for the recovery of solids and oils from suspension drainage and emulsion drainage.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory view showing an embodiment of the present invention and is a plan view of the explanatory view shown in FIG.

[Description of sign]

 1 Tank 2 Rotating Electrode 3 Scraper 4 Drive Motor 5 Fixed Electrode 6 Supply Port 7 Treatment Liquid Outlet 8 Chute

Claims (3)

[Claims] 1. A device for separating a suspension by electrophoretic migration of a suspension of a liquid to be treated and a medium in opposite directions to electrodeposit and deposit the suspension on one electrode. Then, one or more disc-shaped rotating bodies are arranged perpendicularly to the liquid surface, and one of the electrodes is formed by the rotating body to form a rotating electrode.
The other electrode is arranged in parallel with the rotary electrode to form a fixed electrode, and a scraping means for scraping electrodeposits is provided in contact with the surface of the electrode part in the space above the liquid surface at the upper end of the rotary electrode part. Separation device characterized by. 2. The fixed electrode is arranged such that two fixed electrodes are arranged in parallel on both surfaces of the rotating electrode for one rotating electrode.
Separation device. 3. The separation device according to claim 1, wherein a scraper is used as a scraping means for scraping the electrodeposited deposits, and the scraper has a substantially insulating property.