JPS58156309A - Method and apparatus for separating oil and water - Google Patents

Abstract

PURPOSE:To separate an emulsified oil phase (water phase) from water (oil) almost perfectly, by applying alternating voltage to an oil-water dispersion system to carry out oil-water separation. CONSTITUTION:A used washing liquid 2 of a new car is injected into a container 1 from a supply arranged pipe 10 and electrodes 6 are inserted into said used washing liquid 2 to be opposed to each other at an interval of 10cm. In this state, a variable voltage controller 8 is connected to the electrodes 6 to apply alternating voltage (60-120V) thereto. By this method, in a layer 4 wherein colloidal water particles in the used washing liquid are dispersed in oil, the water particles are coagulated and precipitated to separate kerosene. On the other hand, in a layer 5 wherein oil particles are dispersed in water, the oil particles are coagulated to be floated and separated.

Description

Detailed Description of the Invention Technical Field This invention is applicable to systems in which oil such as kerosene is mixed in water in colloidal or suspended form, or conversely, in systems in which water is similarly mixed in oil such as kerosene. -C1 This invention relates to an oil-water separation method and apparatus for separating and recovering the same oil from water.

As is well known in the prior art, when an oil such as kerosene, which is a hydrophobic substance, becomes a colloid or a suspension in water and mixes with water, it becomes difficult to separate it from the water. However, considering the cost involved in this oil quality, there is a demand for recovering the same oil quality by almost completely separating it from water.

For example, the outer surface of a new car body is coated with a wax made of a paraffin compound to make it durable for outdoor storage or transportation, but this wax is washed before the car is delivered to the user. . At present, most of the cleaning methods involve spraying a high-pressure ice-like jet of cleaning fluid, which is a mixture of hot water at about 95° C. and oil such as kerosene, onto the vehicle body to remove -C. Here, the component volume ratio of the cleaning liquid is approximately 95% water and approximately 5% oil. Nowadays, as the number of automobiles produced increases, a large amount of oil such as kerosene is consumed, but only about 15% of this oil is recovered as shown below, and the recovered oil is free from dirt. It was so bad that even though it could be used for combustion, it could not be reused for cleaning.

That is, first, when the cleaning liquid is sprayed onto the vehicle body in the form of a jet stream, the cleaning liquid is subjected to work of shearing and deforming by ultrasonic waves etc. that are generated impulsively, and the water and oil components are torn into minute droplets.

Furthermore, since the wax is left in the atmosphere for a long time before cleaning, its surface becomes oxidized and also attaches or adsorbs minute dust. Since the wax oxides and dirt coexist with hydrophilic groups and hydrophobic groups, they dissolve into the cleaning liquid as surface-active substances during the cleaning process.

The water and oil microdroplets are adsorbed on the surfaces of the water and oil microdroplets, and act to colloidally disperse the water and oil microdroplets into the oil and water dispersion media, respectively.

As shown in Fig. 1, when the washed liquid 2 is placed in a container 1 and left for a while, a floating layer 3 of oil such as kerosene, which has completely separated from the water, and colloidal particles of water are formed in order from the top. Three layers are formed: a water dispersion layer 4 in which oily colloidal particles are dispersed in an oily dispersion medium and made into an emulsion, and an oily dispersion layer 5 in which oily colloidal particles are dispersed in a watery dispersion medium and made into an emulsion. A state of separation is reached.

Conventionally, in most cases, the washed liquid 2 after washing is stored in the container 1 and left for a while as described above, and only the oily floating layer 3 that is naturally separated by gravity is recovered, and other dispersion is not carried out. The oil in layer 4.5 was not separated and was discarded. Therefore, as mentioned above, the amount of oil recovered was at most about 15% of the content before cleaning, and the recovered oil was dirty and could not be reused for cleaning.

Therefore, a large amount of oil has to be consumed and a considerable amount of cost has been incurred for the cleaning liquid. Furthermore, the disposal of the oil-containing dispersion layer has caused a serious problem of environmental pollution.

In addition to the above-mentioned natural separation using gravity, there have been a few separation methods using centrifugation or dissolving an electrolyte. However, centrifugation has the disadvantage that it requires large equipment and electricity to process extremely large amounts of washed liquid. Further, in the method using an electrolytic solution, there is a problem in that when the oil is reused, the remaining electrolytic solution corrodes the vehicle body.

Purpose This invention was made in order to overcome the problems related to conventional oil/water separation as described above.The purpose of the present invention is to almost completely separate emulsified oil from water and reuse it. The object of the present invention is to provide a novel oil-water separation method and device that can reduce costs and save resources, and also contribute to environmental conservation.

EXAMPLE Hereinafter, the structure of an oil-water separator embodying the present invention will be explained with reference to the drawings. First, the first embodiment shown in FIG. 2 will be described. In the drawing, reference numeral 1 is a cylindrical transparent container having an internal volume of 150C. Reference numeral 6 denotes a pair of stainless steel electrodes disposed inside the transparent container 1 so that the surfaces thereof face each other in parallel with an interval of 10α, and -C
1. The thickness of each is 3 mm, and the area of the opposing surface is 8000 CJ.
It is formed into a rectangular shape. A spacer 6a made of an insulator is provided between both electrodes 6 to maintain the distance between the electrodes 6.

7 is a commercial AC power supply with a voltage of 100V or 200V. 8 is a variable voltage regulator whose input side is connected to the commercial AC power supply 7, and whose output side is connected to the pair of 1! !
! Connected to pole 6. 9 is an AC ammeter provided on the output side of the variable voltage regulator 8. 10 is the washed liquid 2
The supply pipe is connected to the upper part of the layer 5, and is provided with a flow rate control valve 11. A water recovery pipe 12 is connected to the bottom of the container 1, and is also provided with a flow rate control valve 13 and a filter 24 for removing inclusions such as wax and dust contained in the separated water. . Reference numeral 14 denotes an oil recovery pipe, which is connected to the lower part of the oil layer after separation, and is also equipped with a flow rate control valve 15 to remove inclusions such as wax and dust contained in the oil after separation. A filter 25 is provided for removal.

Next, the method of use and operation of the first embodiment configured as described above will be explained.

First, about 1001 of the washed liquid 2 after washing a new car is poured into the container 1 through the supply pipe 10. Next, a pair of electrodes 6 are inserted into the washed liquid 2, and their surfaces are opposed in parallel with an interval of 1 OrIR as described above. Next, the output side of the variable voltage regulator 8 is connected to the electrode 6, and an alternating voltage is applied to the washed liquid 2 via the electrode 6. The higher the applied voltage, the higher the speed of oil/water separation, but also the higher the risk of electrical leakage, electric shock, etc. Therefore, the applied voltage is selected to be approximately 60 to 120 V, although there are differences depending on the air temperature, liquid temperature, etc.

In this way, in the water dispersion layer 4 where the water colloid particles are dispersed in an oily dispersion medium such as kerosene and emulsified in the washed liquid 2, the water colloid particles aggregate. It settles and kerosene is separated. To explain this situation according to Fig. 3, the colloidal water 17 has a dielectric constant several tens of times higher than the dispersion medium oil 16, so the force attracted to the electrode or the acceleration per unit volume is also higher for the water 17. is large. Therefore, the surface-active substance 20 is composed of a hydrophobic group 18 and a hydrophilic group 19 forming a diffused electric double layer.
The film of water 17 is broken by the acceleration of the water 1T
is exposed to oil 16.

Since the repulsive force caused by the overlapping electric double layer no longer acts on the exposed and close water 17, they coagulate with each other and increase their radius. The water 17, which has become large enough to overcome gravity, separates from the oil 16 and settles.

Further, in the portion of the oil 16 dispersion layer 5 where the oil 16 colloidal particles are dispersed and emulsified in the water 17 dispersion medium in the washed liquid 2, the oil 16 colloid particles are R. It rises and floats to the surface, and oil 16 is separated. This situation is the fourth
To explain according to the diagram, as mentioned above, the force attracted to the electrode or the acceleration per unit volume is higher than that of oil (16), water (17).
is larger, so the hydrophilic group 19 combined with water 17 becomes water 1.
7 and is strongly pulled and accelerated. Then, the film of the surface-active substance 2a is broken, and the adjacent oils 16 exposed to the water 17 aggregate and float to the surface.

The oily floating layer 3 of the washed liquid 2 is naturally separated by gravity as described above.

As described above, the oil 16 such as kerosene in the washed liquid 2 is almost completely separated from the water 17 10 minutes after the start of current application. Since the container 1 is transparent, completion of separation can be confirmed from the outside. Therefore, the batch process is completed by first opening the valve 15 to collect the oil 16 from the pipe 14, and then collecting the water 17 from the valve 13 and pipe 12.

Alternatively, water 17 and oil 16 may be recovered from the valve 13 and piping 12 in this order. Inclusions such as wax and dust contained in the separated oil 16 are removed by a filter 24 .

Therefore, it is possible to reuse the recovered oil 16 for the purpose of cleaning, thereby reducing costs and saving resources.

Further, since inclusions such as wax and dust are removed from the separated water 17 by the filter 25, it can be reused.

In this case, since only a short time is required from washing to completion of separation, the separated water still has a temperature considerably higher than room temperature.

Therefore, the energy required for heating before reuse is reduced,
Heat utilization efficiency can be increased.

In addition, the oil content that was conventionally discarded can be almost completely recovered, contributing to environmental conservation.

In addition, in the above device, after several minutes of voltage application, the valve 11.1
It is also possible to operate in such a manner that the opening of 3.15 is adjusted in a well-balanced manner, the washed liquid 2 is continuously supplied from the pipe 10, and water and oil are continuously collected from the pipes 12 and 14, respectively.

In addition, in the above device, after several minutes of voltage application, the valve 11
, 13, ' 15 are adjusted in a well-balanced manner, and the cleaned liquid 2 is continuously supplied from the pipe 10, and the oil quality 16 and water 17 are
It is also possible to operate in such a way that the water is continuously recovered from the respective pipes 12 and 14.

Further, although the container 1 is transparent, it may be an opaque container.

Furthermore, this embodiment can be used not only to treat the washed liquid 2 after washing the new car, but also to treat systems in which various types of oil are mixed in water in a dispersed manner. .

Next, a second embodiment of the present invention will be described in accordance with FIG. This is different from one embodiment. That is, in this embodiment, a small diameter part 1a having a cylindrical shape smaller in diameter than the lower part is formed in the upper part of the container 1, and a lid 1b is provided at the upper end of the small diameter part 1a. As a result, the oil 16 becomes a siphon that passes through the small diameter portion 1a when oil/water separation is completed, and the oil recovery port 14B at the end thereof.
The position can be adjusted up and down. Also, electrode 6
Three sets are provided to increase the efficiency of oil and water separation.

Reference numeral 21 is a gas exhaust pipe provided near the upper end of the container 1, and is designed to exhaust oil smoke and gas generated by the electrode 6.

Reference numeral 22 denotes a float sensor placed in the small diameter portion 1a, which includes a hollow sphere, a rod connected to its upper end and gently penetrating the lid 1b, and a detector (not shown) provided at the upper end of the rod. ). The same float sensor 22 has a washed liquid 2 of 16 oil and 1 water.
The sphere is balanced so that when it is separated into 7, the center of the sphere is located at the interface between the oil 16 and water 17 and remains stationary. Reference numeral 23 denotes a fall prevention member attached to the lower part of the small diameter portion 1a to prevent the float sensor 22 from falling into the container 1.

Further, the valves 11, 13, and 15 of this embodiment are electromagnetic valves, and each independently cooperates with the float sensor 22, and the opening/closing of the voltage application circuit also cooperates with the float sensor 22.

Next, the method of use and operation of the second embodiment configured as described above will be explained.

First, the washed liquid 2 is injected into the container 1 via the supply pipe 10. Here, valve 11 is open and valves 13,1
5 is closed. After a certain amount of injection is completed, the oil and water are almost uniformly dispersed at this stage, so the sphere of the float sensor 22 rises to the position shown by the two-dot chain line in FIG. When the float sensor 22 detects the same position, it closes the valve 11 to stop the injection and applies an alternating voltage to the washed liquid 2 via the electrode 6.

The oil-water separation effect is the same as in the first embodiment.

As the separation progresses, the oil 16 accumulates in the small diameter portion 1a and the level of the oil-water interface decreases, so that the float sensor moves downward as shown by the arrow in FIG. When the separation is completed, the float sensor 22 reaches the position indicated by the solid line in FIG. 5, and is laterally opened to collect the oil 16 from the pipe 14. Here, since the bell pipe 14 can be adjusted up and down as described above, the position of the recovery port 14a may be optimally determined. When the oil 16 is recovered after a certain period of time has passed since the valve 15 is opened, the valve 13 is opened and the water 1-i is recovered.

In this way, in the second embodiment, voltage application and valve 11, IS
, 15 are automated, so in addition to the effects of the first embodiment, there is an advantage that processing can be carried out efficiently. Furthermore, the float sensor 22 can also detect leakage of the washed liquid 2 during operation, so it is also excellent in safety.

In the second embodiment, various detectors such as a translucent detector using a phototube may be used instead of the float sensor 22.

Also, like the first embodiment, this embodiment is not only used to treat the washed liquid 2 after washing the new car, but also to treat a system in which various oils are dispersed in water. etc. can also be processed.

Effects As described in detail above, this first invention has an alternating effect on a system in which oil 16 is mixed in water 17 in a dispersed manner or in a system in which water 17 is mixed in oil 16 in a dispersed manner. By applying a voltage, the second invention also arranges at least one pair of electrodes 6 inside the container 1 so as to face each other, and connects each electrode 6 to the alternating current power supply 1 via a variable voltage regulator 8. At the same time, a pipe 1o for supplying a system in which oil 16 is dispersed in water 17 or a system in which water 17 is dispersed in oil 16 is connected to the upper part of container 1. By connecting the piping 12 for recovering the separated water 17 to the bottom of the container 1 and connecting the piping 14 for recovering the separated oil 16 to the upper part of the container 1 corresponding to the oil layer, emulsification is achieved. The resulting oil can be almost completely separated from water and reused, which can reduce costs and save resources, as well as having excellent effects that can contribute to environmental conservation.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view showing the state of natural separation of the washed liquid;
The figure is a perspective view of the first embodiment of an oil-water separator embodying the present invention, FIG. 3 is a schematic diagram showing the state in which colloidal particles of water are dispersed in oil when the device is used, and FIG. Similarly, FIG. 5 is a schematic diagram showing a state in which oily colloidal particles are dispersed in water, and FIG. 5 is a cross-sectional view in which the voltage application circuit of the second embodiment is omitted. Container 1, electrode 6, commercial AC power supply 7, variable voltage regulator 8
, supply pipe 1o, water recovery pipe 12, oil recovery pipe 14,
Oil quality 16, water 11, float sensor 22, filter 24
, Filter 25° Patent Applicant Haruhiko Nomura Daiichi Co., Ltd. Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] l A system in which oil (16) is dispersed in water (17) or a system in which water (17) is dispersed in oil (16) An oil/water separation method characterized by applying an alternating voltage to the voltage. 2. At least a pair of electrodes (6) are arranged inside the container (1) so as to face each other, and each electrode (6) is connected to an alternating current power supply (7) via a variable voltage regulator (8). At the same time, a system in which oil (16) is dispersed in water (1'7) or a system in which water (17) is dispersed in oil (16) is supplied. Piping (10) to container (1)
A pipe (17) connected to the top of the
12) to the bottom of the container (1), and the separated oil (1
6) to the container (14) corresponding to the oil layer.
1) An oil-water separator characterized in that it is connected to the upper part of. 8. A detector (22) is newly installed on the inner wall of the container (1), and when the detector (22) detects that a certain amount of each group has accumulated, the application of an alternating voltage is started,
The oil-water separator according to claim 2, characterized in that the application of the alternating voltage is stopped upon detecting that the separation of each group of oil (16) and water (17) is completed. 4. The pipes (14) and (12) are provided with filters (25) and (24) for removing inclusions contained in the separated oil (16) and water (17), respectively. An oil-water separator according to claim 2 or 8.