JPH06304568A - Flocculating and separating device - Google Patents

Abstract

PURPOSE:To provide a flocculating and separating device by which colloidal solid particles are effectively flocculated and separated from a liquid to be treated without using chemicals and which is constituted as relatively small-sized equipment. CONSTITUTION:In a separation tank 1 is formed the 1st partition chamber 4 adjacent to an electrode chamber 7, and a pass for a liquid to be treated is provided above a partition plate 15 dividing the 1st partition chamber 4 from the electrode chamber 7. The 2nd partition chamber 5 is formed adjacently to the 1st partition chamber 4, and a tank filter 2 to which the 1st partition chamber 4 and the 2nd partition chamber 5 are connected with pipe lines is formed. In the tank filter 2, electrodes 23 and a filter 24 are arranged, and also a highfrequency power source 3 for acting the high-frequency electric field, on the liquid to be treated in the tank filter by applying high-frequency voltage to the electrodes 23 is connected to the electrodes. After the liquid to be treated in the 1st partition chamber 4 is passed through the tank filter 2, it is returned to the 2nd partition chamber 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aggregating and separating apparatus for aggregating and separating fine solid particles contained in industrial waste liquids.

[0002]

2. Description of the Related Art For example, colloidal paint particles are contained in a cleaning waste liquid discharged from a cleaning process during electrodeposition coating.
That is, very small solid particles are mixed. In order to separate solid particles from this type of electrodeposition coating waste liquid, conventionally, a coagulant such as aluminum sulfate or iron sulfate or a neutralizing agent is generally added to the waste liquid to coagulate / precipitate the particles in the waste liquid. , They are separated from the waste liquor.

[0003]

However, in the method of aggregating and separating solid particles using a coagulant or a neutralizing agent, the equipment includes a flocculant charging tank, a neutralizing agent charging tank, a precipitation tank, etc. Since it is necessary to provide a large number of tanks, there is a problem that the installation space and equipment costs are high.

Further, when the coagulant is put into the waste liquid for coagulation treatment, the coagulant itself may change into sludge in the tank. In some cases, the sludge caused by the coagulant is far more than the solid matter in the waste liquid. However, there is a problem that a more complicated removal process is required to remove the sludge.

The present invention has been made in view of the above points, and is capable of efficiently aggregating and separating colloidal solid particles from a liquid to be treated without using a chemical, and is a relatively small facility. It is an object of the present invention to provide a flocculation / separation device that can be configured as.

[0006]

In order to achieve the above object, in the coagulation / separation apparatus of the present invention, an electrode chamber is formed by partitioning the inside of a separation tank with partition plates to form an electrode chamber. A high-frequency power source for applying an AC / high-frequency voltage is connected between the electrode plates and the chamber wall, and a first partition chamber is formed adjacent to the electrode chamber in the separation chamber. A passage for the liquid to be treated is provided in the upper part of the partition plate, a second partition chamber is formed adjacent to the first partition chamber, and a filtration tank connected to the first partition chamber and the second partition chamber by a pipeline. Is installed, an electrode and a filter are arranged in the filtration tank, a high-frequency power source for applying an AC / high-frequency voltage to the electrode is connected to the electrode, and the liquid to be treated in the first partition chamber is passed through the filtration tank. It is configured to be returned to the second compartment. Here, AC / high-frequency voltage is about 1 kHz
AC voltage having a frequency of z to about 500 kHz.

[0007]

In the coagulation / separation device thus constructed, the liquid to be treated (waste liquid containing fine solid particles) supplied into the electrode chamber of the separation tank is converted into an electric field by an AC / high frequency voltage applied between the electrode plates. The solid-state particles in the liquid are vibrated by this high-frequency electric field, and the electrokinetic potential (zeta potential) of the particles is neutralized, so that the solid-state particles aggregate. At the same time, metal ions eluted from the electrode plate react with hydroxide ions in the liquid to form flocs, and the solid particles in the liquid are entrained and aggregated. The liquid to be treated containing the aggregated solid particles flows into the first partition chamber, and the liquid to be treated in the first partition chamber is sent to the filtration tank. In the filter tank,
AC / high-frequency voltage is applied to the electrodes from the high-frequency power supply, and the liquid to be treated in the bath is again subjected to the action of the high-frequency electric field when passing through the periphery of the electrodes and passing through the filter.

At this time, in the liquid to be treated in the filtration tank, as in the case of the separation tank, the electrokinetic potential (zeta potential) of the particles in the liquid is neutralized by the electric field, and the solid particles are aggregated into coarse particles. The solid particles that have been accelerated and are agglomerated and coarsened are adsorbed on the pore surfaces of the filter, and the liquid to be treated (water) from which the solid particles have been removed is returned to the second partition chamber of the separation tank. And
The liquid to be treated after separation is taken out from the second partition chamber.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a longitudinal sectional view of the flocculating and separating apparatus, and FIG. 2 shows a transverse sectional view thereof. This apparatus contains a liquid to be treated consisting of a waste liquid such as a cleaning liquid after electrodeposition coating, and a rectangular box-shaped separation tank 1 in which an electric field is applied to perform coagulation separation.
And a cylindrical tank type filtration tank 2 connected by a pipe line between the first partition chamber 4 and the second partition chamber 5 of the separation tank 1.

A supply port 11 for supplying a liquid to be treated is provided at one end of the separation tank 1 so as to be connected to a supply pipe, and an electrode chamber 7 is formed in the tank near the supply port 11. 7, a plurality of electrode plates 12 and 13 are vertically arranged at regular intervals. The electrode plate 12 is fixed to the wall portion of the separation tank 1 via an insulating plate 14, and the electrode plate 13 is provided so as to project inward from the wall portion of the separation tank 1. In addition, spaces are formed between the lower end portions of the electrode plates 12 and 13 and the bottom portion of the separation tank 1 and the leading end portions of the electrode plates 12 and 13 to form passages for the liquid to be treated.

A conductive metal such as iron or aluminum is used for the electrode plates 12 and 13, and a high frequency power source 3 for applying an AC / high frequency voltage is connected between them. As shown in FIG. 3, the high frequency power supply 3 includes a high frequency signal generator 31 that generates a high frequency signal, a voltage amplifier 32 that inputs the high frequency signal output from the high frequency signal generator 31, and amplifies the voltage, and a voltage amplifier 32. Current amplifier 3 for current amplification of the output signal
3 and a current control circuit 34. The output side of the current amplifier 33 is connected to the electrode plates 12 and 13 in the separation tank 1.

The high frequency signal generator 31 has a high frequency oscillator for generating an AC / high frequency signal of about 1 kHz to about 500 kHz, and oscillates and outputs a frequency signal that can be set arbitrarily. Further, the high frequency signal generator 31 is switchably provided with a sine wave output circuit that outputs the oscillated high frequency signal as a sine wave, a rectangular wave output circuit that outputs a rectangular wave, and a sawtooth wave output circuit that outputs a sawtooth wave. Then, the high-frequency signal having the selected waveform is output.

In general, when an electric field is applied to a liquid to be treated such as a waste liquid to conduct an agglomeration treatment, as the agglomeration of particles progresses, the electrical conductivity of the liquid changes and the current value flowing between the electrodes gives the best agglomeration efficiency. It deviates from the current value that exerts. Therefore, a current control circuit 34 that controls the output current of the current amplifier 33 is provided.

The current control circuit 34 detects the output current value of the current amplifier 33, compares the current value with a preset current set value, and when the current values are different, the voltage amplifier 32.
A voltage adjustment signal for adjusting the voltage is output to adjust the voltage to adjust the output current value of the current amplifier 33 to the current setting value. This current control circuit 34
Also operates as a protection circuit that shuts off the output of the current amplifier 33 when the load current rises abnormally due to a short circuit between the electrodes.

The electrode chamber 7 has a partition plate 1 rising from the bottom.
It is partitioned by 5, and the space above the partition plate 15 serves as a passage for the liquid to be treated. Further, another partition plate 19 is provided on the right side of the partition plate 15 so as to vertically partition the upper part to the lower part of the tank, and the partition plates 15 and 19 form the first partition chamber 4 adjacent to the electrode chamber 7. It

Further, another partition plate 9 is provided on the right side of the partition plate 19.
Are vertically arranged, and the second partition chamber 5 is formed next to the first partition chamber 4 by the partition plates 19 and 9. A thin communication pipe 19a is provided below the partition plate 19 that partitions the first partition chamber 4 and the second partition chamber 5 in order to match the water levels in the two chambers.
Further, a passage for the liquid to be treated is formed between the lower end of the partition plate 9 and the bottom of the tank.

A discharge chamber 6 for discharging the treated water is formed on the right side of the partition plate 9. A discharge port 8 is provided on the upper side wall of the discharge chamber 6, and a water discharge pipe is connected to the discharge port 8. The height position of the discharge port 8 determines the liquid level position of the liquid to be treated in the tank, and the liquid level position is the electrode plates 12, 1
It is set to be located slightly above 3. The side wall of the first partition chamber 4 and the second partition chamber 5 is connected to a connection pipe connected to a filtration tank 2 described later.

In the filtration tank 2, a cylindrical electrode 23 and a filter 24 are arranged in a cylindrical container 20, a discharge pipe 25 is provided in the central vertical direction, and a supply pipe 28 is connected to the upper side wall of the tank. Consists of

The upper part of the container 20 is closed by an upper plate 21, and a cylindrical electrode 23 is attached to the lower surface of the upper plate 21 via an insulating plate 22. A cylindrical filter 24 is concentrically arranged inside the electrode 23, and the outer periphery of the filter 24 is surrounded by a metal porous plate 24a. A discharge pipe 25 is attached inside the filter 24 so as to be inserted from below. The container 20 and the discharge pipe 25 are made of a conductive metal so as to form the other electrode.

The filter 24 is composed of an adsorbent such as activated clay, zeolite, activated carbon and silica gel, and adsorbs the aggregated solid particles in the liquid to be treated on the surface of a large number of pores formed therein.

The supply pipe 28 is connected to the discharge side of the pump 26, and the suction side of the pump 26 is the first partition chamber 4 of the separation tank 1.
Is connected to the lower part of the pipe. The end of the discharge pipe 25 is connected to the lower part of the second partition chamber 5 of the separation tank 1. By the operation of the pump 26, the liquid to be treated in the first partition chamber 4 of the separation tank 1 is sent to the filtration tank 2 and returned to the second partition chamber 5 again.

Further, the container 20 of the filtration tank 2 (the discharge pipe 2
The high frequency power source 3 is connected between 5) and the electrode 23 and the porous metal plate 24a. The high frequency power supply 3 is configured in the same manner as described above, that is, as shown in FIG. 3, and applies an AC / high frequency voltage between the container 20 (exhaust pipe 25), the electrode 23 and the metal porous plate 24a.

Next, the operation of the flocculation / separation device having the above-mentioned structure will be described.

The supply port 11 of the separation tank 1 is connected to a supply pipe of a supply pump (not shown), and is passed from a waste liquid tank in which a liquid to be treated (for example, cleaning waste liquid after electrodeposition coating) is stored through the pump and the supply pipe. A liquid to be treated is supplied into the separation tank 1. Then, the pump 26 is started to send the liquid to be treated in the first partition chamber 4 to the filtration tank 2, and the high frequency power source 3 causes the electrode plates 12, 13
A voltage is applied between them, and in the filtration tank 2, a voltage is applied between the container 20 and the electrode 23 and the metal porous plate 24a from the high frequency power source 3 to start the aggregation / separation process.

The AC / high frequency power output from the high frequency power supply 3 has a frequency of about 1 kHz to about 500 kHz and a current of about 0.0.
The voltage is about 5 A to about 2 A and the voltage is about 20V. The higher the voltage is, the better the aggregation efficiency is, but from the viewpoint of safety, it is set to about 20V.

The liquid to be treated, which has entered the electrode chamber 7 of the separation tank 1 through the supply port 11, is subjected to the action of an electric field due to the AC / high-frequency voltage applied between the electrode plates 12 and 13, and this high-frequency electric field causes the liquid to be treated in the liquid. The solid particles of (3) vibrate, and the interfacial potential (zeta potential) of the particles is neutralized, and the aggregation and coarsening of the solid particles are promoted. Further, the metal ions eluted from the electrode plates 12 and 13 react with hydroxide ions in the liquid to form flocs, and the solid particles are aggregated while being entrained.

The liquid to be treated in the electrode chamber 7 is the partition plate 1.
Go over 5 and enter the first partition room 4. Further, the liquid to be treated in the first partition chamber 4 is sent to the filtration tank 2 by the operation of the pump 26 and enters the container 20.

In the filtration tank 2, the container 2 is driven by the high frequency power source 3.
0 between the electrode 23 and the porous metal plate 24a, and the discharge pipe 25
An AC / high frequency voltage is applied between the electrode 23 and the porous metal plate 24a. The liquid to be treated that has entered the container 20 passes around the electrode 23, passes through the filter 24, and is guided to the discharge pipe 25, while the liquid to be treated is again subjected to the action of the high frequency electric field.

At this time, as in the case of the separation tank 1, the solid particles contained in the liquid to be treated are vibrated by the high frequency electric field, and the interfacial potential (zeta potential) thereof is neutralized, so that the solid particles Aggregation and coarsening are performed. As a result, when the solid particles that have aggregated and become coarse particles pass through the filter 24, they are adsorbed together with other impurities on the surface of many pores formed therein, and the solid particles are removed. The liquid (water) is returned from the discharge pipe 25 to the second partition chamber 5 of the separation tank 1.

The liquid to be treated (water) returned to the second partition chamber 5 of the separation tank 1 is sent from the lower side of the partition plate 9 to the adjacent discharge chamber 6 and is discharged to the upper part of the discharge chamber 6. The processed liquid that has overflowed from the outlet 8 is sent to a predetermined tank or the like through a pipe.

When the amount of solid particles in the liquid is large,
The liquid to be treated that has overflowed from the discharge port 8 is returned to the waste liquid tank again, is returned to the separation tank 1 again by the supply pump, and the same treatment as described above is performed a plurality of times.

After the solid particles in the liquid are aggregated by applying the high frequency electric field in the separation tank 1 as described above, the liquid to be treated is sent to the filtration tank 2 again and the high frequency electric field is applied, and the adsorbent is removed. Since it is filtered through the filter 24 containing the solid particles, the solid particles are effectively aggregated even in the liquid to be treated containing the highly stable colloidal solid particles, and the aggregated solid matter is coarsened. It can be efficiently removed and separated by the filter 24.

[0034]

[Test Example] In order to confirm the effects of the above invention, the cleaning waste liquid actually used for cleaning after electrodeposition coating was used as a sample waste liquid,
This sample waste liquid is subjected to a high-frequency electric field of 60 kHz by this device to cause coagulation / separation treatment, and COD (chemical oxygen demand), TOC (total organic carbon compounds), and evaporation residue contained in the sample waste liquid after the treatment. Was measured.

The measurement results are shown in Table 1. The measurement method is
According to JIS-K0102, as a comparative example, 60
An example of a case where a commercial alternating electric field of Hz is applied to the sample waste liquid to treat the sample waste liquid is also shown.

[0036]

[Table 1]

From this test example, it is possible to separate and remove more solid particles by the device of the present invention when a high-frequency electric field is applied to perform coagulation separation, as compared with the case where an electric field of a commercial AC power supply is applied. I understand.

By the way, the stable dispersion energy of emulsion particles contained in the cleaning waste liquid after electrodeposition coating is
Generally, it is 10 ^-18 to 10 ^-19 Joules, and it is considered that particles are aggregated when a vibration electric energy higher than this is applied to the particles by applying an electric field.

A particle having a particle diameter of R is about (1/10) R
When vibrated with an amplitude of ~ R, its vibration energy Es
Is calculated from the equation of Es = 2πm ² f ² a ² . Here, m is the particle mass, f is the frequency of vibration, and a is its amplitude.

The relationship between the vibration energy of the particles, the particle diameter, and the frequency of the applied electric field calculated from this equation is plotted in the graph shown in FIG.

From this graph, it is understood that when the frequency of the applied electric field is 60 Hz, particles having a diameter of about 10 μm to 20 μm or more agglomerate, and when the frequency is 60 kHz, particles having a diameter of about 1 μm or more agglomerate. Therefore, since the diameter of the emulsion particles in the cleaning waste liquid is about 1 μm to 5 μm, it is possible to effectively agglomerate the particles of this kind by applying a high frequency electric field of 60 kHz. It agrees well with the result of the test example shown in.

[0042]

As described above, according to the coagulation / separation apparatus of the present invention, the inside of the separation tank is partitioned by partition plates to form a plurality of electrode plates to form an electrode chamber. A high-frequency power supply that applies AC / high-frequency voltage is connected between the plate and the tank wall, and a first partition chamber is formed adjacent to the electrode chamber in the separation tank. A passage for the liquid to be treated is provided in the upper part, a second partition chamber is formed adjacent to the first partition chamber, and a filtration tank connected to the first partition chamber and the second partition chamber by a pipeline is installed. An electrode and a filter are arranged in the filtration tank, a high-frequency power source for applying an AC / high-frequency voltage to the electrode is connected to the electrode, and the liquid to be treated in the first partition chamber is passed through the filtration tank and then in the second partition chamber. I configured it back, so
A high-frequency electric field is applied to the liquid to be treated in the separation tank and the filtration tank, the high-frequency electric field vibrates the solid particles, and the electrokinetic potential of the particles is neutralized to efficiently agglomerate and coarsen the solid particles. It can be granulated, and the aggregated solid matter can be removed / separated by the filter of the filtration tank.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a flocculation / separation device showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the device.

FIG. 3 is a configuration diagram of a high frequency power supply 3.

FIG. 4 is a graph showing a relationship between vibration energy of particles, particle diameter, and frequency of an applied electric field.

[Explanation of symbols]

 1-separation tank, 2-filtration tank, 3-high frequency power supply, 4-first partition chamber, 5-second partition chamber, 7-electrode chamber, 9,15-partition plate, 12,13-electrode plate, 23- Electrode, 24-filter.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noboru Inoue 727 Funaki-cho, Ono-shi, Hyogo (72) Inventor Naoki Abe 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Corporation

Claims (2)

[Claims] 1. A high frequency for applying an AC / high frequency voltage between the electrode plates or between the electrode plates and the tank wall by partitioning the inside of the separation tank with a partition plate to arrange a plurality of electrode plates. A power source is connected, a first partition chamber is formed in the separation tank adjacent to the electrode chamber, and a passage for the liquid to be treated is provided above the partition plate partitioning the first partition chamber and the electrode chamber. A second partition chamber is formed adjacent to the first partition chamber, a filtration tank connected to the first partition chamber and the second partition chamber by a pipe line is installed, and an electrode is provided in the filtration tank. A filter is provided, a high-frequency power source for applying an AC / high-frequency voltage to the electrode is connected to the electrode, and the liquid to be treated in the first partition chamber is passed through the filtration tank and then returned to the second partition chamber. A flocculation / separation device configured as described above. 2. A pump is connected to a pipe line between the filtration tank and the first partition chamber or the second partition chamber, and a metal porous plate forming a part of an electrode is provided on the outer periphery of the filter of the filtration tank. The coagulation / separation device according to claim 1.