JP2000279707A - Oil-water separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil-water separator which is capable of sufficiently removing water and is long in device life. SOLUTION: Waste oil to be subjected to an oil-water separation is introduced from an introducing pipe 131 into a separation tank 110. The bottom of the separation tank 110 is previously provided with a froth generating means 120. Dry air is supplied from an air supplying means 125 into a hollow substrate 121 constituting the froth generating means 120. A multiplicity of bowl-shaped bodies 122 using sintered metals of about 20 μm in pore size are arranged atop a substrate 121. The dry air is released in the form of froth into the waste oil through the microporous structures of these bowl-shaped bodies 122. The water in the waste oil is captured by the froth and is discharged outside from an air discharge pipe 134. A reflux path where the oil is returned from a reflux pipe 132 through the introducing pipe 131 into the separation tank 110 is formed. Impurity removal by a filter is executed on this reflux path and the oil is heated to about 60 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-water separator, and more particularly to an oil-water separator which can be used in a process for extracting reclaimed oil from waste oil.

[0002]

2. Description of the Related Art Compressors for refrigerators and air conditioners include:
Lubricating oil is injected inside. When discarding used compressors or the like, lubricating oil is collected by drilling or cutting a large compressor. Also, for small compressors,
Although it may be thrown into a crusher and disposed of as it is, smoke is generated. Therefore, it is desired to extract and collect the lubricating oil by some method. In any case, the recovered waste oil is in a state in which a large amount of water is turbid together with a large number of impurity particles (iron powder, other refuse). From the point of view of resource reuse, remove impurities from this waste oil,
Preferably, the reclaimed oil is extracted and made available.
A filter is usually used to remove the impurity particles. By passing through a plurality of filters from a coarse filter to a fine filter, most of the impurity particles can be removed. However, water contained in waste oil cannot be completely removed by a normal filter. Therefore, an oil-water separator for removing water from such a mixture of oil and water and leaving only oil is used.

Conventionally, a general oil-water separator used for extracting regenerated oil from waste oil has a mechanism for removing water by spraying waste oil from which impurity particles have been removed into a vacuum chamber. ing. That is, while maintaining a constant degree of vacuum inside the chamber using a vacuum pump,
When the waste oil is sprayed from a nozzle provided with an outlet in the chamber, the water in the atomized waste oil evaporates and is discharged to the outside by a vacuum pump, and the remaining oil accumulates at the bottom of the chamber. Then, if the oil finally collected at the bottom of the chamber is recovered, it is possible to obtain a regenerated oil from which water has been removed.

[0004]

However, the above-mentioned conventional oil / water separator has the problems that the efficiency of water removal is low and the life of the device is short. That is, water is removed by atomizing the waste oil in a vacuum chamber, so that the contained water cannot be completely removed, and in fact, in the oil accumulated at the bottom of the chamber, Significant moisture will remain. Further, the removed water is discharged to the outside by the vacuum pump, and naturally passes through the vacuum pump. For this reason, the oil inside the vacuum pump deteriorates more quickly, and the metal parts constituting the vacuum pump are easily rusted. As a result, the life of the device is shortened.

Accordingly, an object of the present invention is to provide an oil-water separation device capable of sufficiently removing water and having a long life.

[0006]

Means for Solving the Problems (1) A first aspect of the present invention is an oil-water separation apparatus that performs a process of removing water from a mixed liquid of oil and water and leaving only oil, and is a target of separation. A separation tank containing the mixture, a mixture introduction means for introducing the mixture into the separation tank, an air supply means for supplying dry air, and the supplied dry air inside the mixture contained in the separation tank. And a bubble generating means for discharging the air in the form of bubbles and an air discharging means for releasing the air in the separation tank to the outside.

(2) A second aspect of the present invention is the above-mentioned first aspect.
In the oil-water separation device according to the aspect, the liquid mixture in the separation tank is once led out to the outside, and a return path is formed back into the separation tank again. In the middle of the return path, the mixed liquid being refluxed is heated. A heating device is provided.

(3) The third aspect of the present invention is the above-mentioned second aspect.
In the oil-water separation device according to the aspect, a filter for removing impurity particles or large water droplet particles contained in the mixed solution is provided in the reflux path.

(4) The fourth aspect of the present invention is the above-mentioned first aspect.
In the oil-water separator according to the aspect of the present invention, the foam generating means is constituted by a structure in which a large number of bowl-shaped bodies made of sintered metal having a microporous structure are arranged in a prone state, and dry air is passed through the microporous structure. It is designed to be released into the mixture.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a side sectional view showing a basic configuration of an oil-water separation device 100 according to one embodiment of the present invention.
The main components of this device are a separation tank 110 and a cover plate 115 for storing the mixed liquid to be separated, a foam generating means 120 for discharging dry air into the mixed liquid stored in the separation tank 110 in a foamed state, Air supply means 125 for supplying dry air to the foam generating means 120, a mixed liquid introduction pipe 131 for introducing the mixed liquid into the separation tank 110, a reflux pipe 132 for refluxing the mixed liquid in the separation tank 110, and an air supply means 125 An air introduction pipe 133 for guiding dry air supplied from the air to the bubble generation means 120, and an air discharge pipe 134 for releasing air in the separation tank 110 to the outside.

The bubble generating means 120 is provided in the substrate 1 having a hollow inside.
21 and a large number of bowl-shaped bodies 122 arranged on the upper surface of the substrate 121. The bowl-shaped body 122 has a shape in which a cup is turned down, and has a function of discharging bubbles of dry air from the surface thereof. FIG. 2 shows one bowl 12
FIG. 2 is an enlarged side sectional view showing a peripheral portion of No. 2; Bowl 1
Each of the wall surfaces 22 is made of a sintered metal having a microporous structure. More specifically, a large number of fine metal powders are collected and sintered so as to form a bowl-shaped structure. In the apparatus according to the present embodiment, the pore size (the size of the fine pores) is about 20 μm. Uses binding metal. If the bowl-shaped body 122 having such a fine pore structure is used, the separation tank 11
The mixed liquid in 0 does not permeate into the bowl-shaped body 122.

On the other hand, inside the bowl-shaped body 122, the substrate 1
Dry air is supplied through an opening 123 formed on the upper surface of the upper surface 21, and the dry air is discharged into the mixture through the fine structure of the wall surface of the bowl 122. The dry air thus released becomes fine bubbles, moves upward in the mixed solution, escapes from the liquid surface of the mixed solution, and flows out of the air discharge pipe 134.
And will be discharged to the outside. A large number of bowls 122 are arranged in a two-dimensional matrix on the upper surface of the substrate 121, and a large number of fine bubbles are released into the mixture. In addition, since these bubbles are bubbles of dry air, they function to efficiently take in moisture contained in the mixture while moving through the mixture. Thus, the water in the mixed liquid stored in the separation tank 110 escapes from the liquid while being taken in the bubbles of the air, and is discharged from the air discharge pipe 1.
34, it is discharged to the outside. As for the discharge of air by the air discharge pipe 134, natural discharge is sufficient, and there is no need to use a vacuum pump or the like. Therefore, there is no problem that the apparatus itself is deteriorated by the moisture contained in the exhaust air.

FIG. 3 is a system configuration diagram showing an example of constructing a waste oil refining system using the above-described oil / water separation device 100. Oil-water separation device 1 shown in the upper almost central position
Reference numeral 00 denotes the above-described oil-water separator shown in FIG. 1, in which a foaming means 120 is provided in a separation tank 110. The oil storage tank 200 shown on the lower left of the figure is for temporarily storing waste oil to be refined, and the reclaimed oil drum 300 shown on the lower right of the figure collects refined regenerated oil. It is for doing. Hereinafter, a waste oil refining process using the waste oil refining system will be described step by step. In addition, in addition to the various components illustrated in the actual system, a check valve, an air release valve, a drain valve, a safety valve, a pressure control valve, a flow meter, a pressure gauge, and the like are provided.
Here, description of these detailed components will be omitted.

First, waste oil to be refined is injected from a waste oil introduction port, and is introduced into an oil storage tank 200 through a magnetic strainer ST1, a pump P1, and a valve V1. Actually, when the valve V1 is opened and the pump P1 is operated, the waste oil is automatically sucked up from the waste oil introduction port and poured into the oil storage tank 200. At this time, the magnetic strainer ST1 functions to attract and remove iron powder and the like in the waste oil by magnetic force. In this way, when the waste oil to be refined is accumulated in the oil storage tank 200, the three-way valve V2 is switched so as to pass downward from the left, and the pump P2 is operated. Thus, the waste oil in the oil storage tank 200 is pumped up to the pump P2 through the three-way valve V2 and the magnetic strainer ST2. Here, the three-way valve V3 is further switched so as to communicate upward from the left, the valve V4 is opened, and the valve V5 is closed, so that the pumped waste oil is further subjected to the three-way valve V3, the magnetic filter F1, and the heating device. The liquid is introduced into the separation tank 110 through the mixed liquid introduction pipe 131 through the apparatus H and the valve V4. When the waste oil in the oil storage tank 200 has been transferred into the separation tank 110 in this way, the work in the preparation stage is completed.

Next, the operation of oil / water separation is finally started. That is, the external air is taken in and compressed by the compressor CP, and the air dryer A passes through the valve V6.
Send to D. The air dryer AD is a container containing a large amount of a desiccant, and the air passing through the air dryer AD becomes dry air having a humidity close to 0%. As a result, the compressor CP and the air dryer AD function as the air supply means 125 in the device shown in FIG. Dry air supplied from the air dryer AD is supplied to the valve V7.
Through the air introducing pipe 133 to the bubble generating means 120. As described above, the bubbles of the dry air are released from the foam generation means 120 to the waste oil in the separation tank 110. The bubbles take in the water in the waste oil, escape from the liquid surface, and are discharged from the air discharge pipe 134 to the outside. In this embodiment, the air discharge pipe 1
A trap TR is provided in the middle of 34 so as to trap oil discharged together with bubbles. Further, a mist filter MF is provided in front of the mist filter so as to prevent other impurities from being discharged into the atmosphere.

As described above, if bubbles of dry air were continuously sent to the waste oil in the separation tank 110, the water contained in the waste oil was gradually discharged, and the water was eventually almost completely removed. You can get oil. However, in the system according to the present embodiment, the liquid mixture in the separation tank 110 is once led out to the outside and returned to the separation tank 110 again so that the oil / water separation operation can be performed more efficiently. The road C is formed. That is, as shown by the arrow in the drawing, the reflux path C is connected to the three-way valve V2 and the magnetic strainer S by a reflux pipe 132 provided on the bottom surface of the separation tank 110.
The path passes through T2, the pump P2, the three-way valve V3, the magnetic filter F1, the heating device H, and the valve V4, and returns to the separation tank 110 via the mixed solution introducing pipe 131. In order to form such a recirculation path C, the three-way valve V2 may be switched so as to communicate downward from the right. When the operation of recirculating the waste oil in the separation tank 110 along the above-described recirculation path C while discharging the foam of the dry air from the foam generating means 120 is performed,
Oil-water separation work can be performed more efficiently.

This reflux operation has two significances. The first significance is that the magnetic strainer ST2
And a magnetic filter F1 is provided, and every time waste oil passes therethrough, impurity particles such as iron powder are removed. Therefore, by repeatedly performing the reflux operation, the impurity particles are gradually removed from the waste oil in the separation tank 110. The second significance is that a heating device H is provided in the middle of the circulation path C, and the waste oil being refluxed is heated here. By the heat treatment of the heating device H, the separation tank 1 passes through the mixed solution introduction pipe 131.
The waste oil returned into 10 is in a heated state, and the contained water is more likely to evaporate. Therefore, the operation of removing moisture by the bubbles discharged from the bubble generating means 120 is performed more efficiently. The temperature of the heat treatment by the heating device H is about 60 in this embodiment.
° C. If only the purpose of water removal is the purpose, it is possible to set a higher temperature, but if a higher temperature setting is performed, there is a risk of oil deterioration, so for the purpose of using recycled oil, About 60 °
Heating on the order of C appears to be optimal.

In this embodiment, the return path C
In addition, a detour is provided. That is, when the valve V4 is closed and the valve V5 is opened, the recirculating waste oil bypasses the oil-water separation filter OWS. The oil-water separation filter OWS is a filter for removing large water droplet particles (water droplet particles that can be removed by the filter) contained in the waste oil. The waste oil introduced from the oil storage tank 200 to the oil-water separator 100 initially has large water droplet particles in a turbid state. It is more effective to remove such large water droplet particles with a dedicated filter. Therefore, for a while after the reflux operation is started, the waste oil is caused to pass through the detour, and the oil-water separation filter OWS is used.
Preferably, an operation of removing larger water droplet particles is performed. If the reflux operation through this bypass is performed for a certain period of time, large water droplet particles are almost completely removed. At this point, the valve V5 may be closed, the valve V4 may be opened, and the flow may return to the normal circulation path C.

As described above, if the operation of removing water due to the generation of bubbles is repeated for several hours while performing the reflux operation, the oil in the separation tank 110 will be in a state in which almost all of the impurity particles and moisture have been removed. Finally, when the oil in the separation tank 110 reaches the intended quality as regenerated oil,
This purification operation is completed. When the refining work is completed, the three-way valve V3 is switched from the left side to the lower side,
The oil flowing in the return path C is collected in the reclaimed oil drum 300 through the magnetic filter F2.

Finally, using this waste oil refining system,
The oil-water separation efficiency when the work of refining waste oil into reclaimed oil is actually performed will be described. The graph shown in FIG. 4 is a graph showing the oil-water separation efficiency when only the supernatant portion of waste oil used as lubricating oil for refrigerators and the like is taken into this waste oil purification system and subjected to a purification treatment. The horizontal axis indicates the total time (unit: minute) during which the above-described purification treatment (the treatment of generating water and removing water while performing the reflux operation) is performed, and the vertical axis indicates the oil in the separation tank 110. Indicates the amount of water (unit: ppm) contained in the. In the illustrated example, the water initially contained in the waste oil at about 600 ppm decreased with time, and when the refining operation was continued for about 500 minutes, it was only about 30 ppm. On the other hand, the graph shown in FIG. 5 is a graph showing the oil-water separation efficiency when the entire waste oil used as the lubricating oil is taken into the waste oil refining system and subjected to the refining treatment. Initially, 3 for waste oil
The moisture contained near 000 ppm decreased with time, and was only about 20 ppm when the purification operation was continued for about 10,000 minutes. Practically, if the refining operation is performed continuously for about 8 hours, a regenerated oil of sufficient quality can be obtained.

As described above, the present invention has been described based on the illustrated embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various other forms.
For example, the structure of the foam generating means 120 does not necessarily need to be a structure using the bowl-shaped body 122. In other words, any structure can be used as long as it can emit bubbles due to dry air in a mixture of water and oil. Such a structure may be used.
The configuration of the waste oil refining system shown in FIG. 3 is also an example, and the configuration of the pipeline, the position of the valve, and the like can be appropriately changed according to the specifications.

[0022]

As described above, according to the oil-water separator according to the present invention, since the water is removed by the bubbles of the dry air, an oil-water separator having a sufficient water removal and a long service life is provided. can do.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a basic configuration of an oil-water separation device according to an embodiment of the present invention.

FIG. 2 is an enlarged side sectional view showing a peripheral portion of a bowl-shaped body in the apparatus shown in FIG.

FIG. 3 is a system configuration diagram showing an example in which a waste oil refining system is constructed using the oil-water separation device 100 shown in FIG.

4 is a graph showing oil-water separation efficiency when only a supernatant portion of waste oil used as a lubricating oil for a refrigerator or the like is taken into a waste oil purification system shown in FIG. 3 and subjected to a purification treatment.

5 is a graph showing oil-water separation efficiency when the entire waste oil used as a lubricating oil for a refrigerator or the like is taken into the waste oil purification system shown in FIG. 3 and subjected to a purification treatment.

[Description of Signs] 100 ... oil / water separator 110 ... separation tank 115 ... cover plate 120 ... bubble generating means 121 ... substrate 122 ... cup-shaped body 123 ... opening 125 ... air supply means 131 ... mixed liquid introduction pipe 132 ... reflux pipe 133 ... air introduction pipe 134 ... air discharge pipe 200 ... oil storage tank 300 ... reclaimed oil drum can AD ... air dryer C ... recirculation path CP ... compressor F1, F2 ... magnetic filter H ... heating device MF ... mist filter OWS ... oil-water separation filter P1, P2: pump ST1, ST2: magnetic strainer TR: trap V1-V7: valve / three-way valve

Claims (4)

[Claims] An oil-water separator for removing water from a mixture of oil and water to leave only oil, comprising: a separation tank containing a mixture to be separated; A mixture introducing means for introducing the mixture, an air supply means for supplying dry air, a bubble generating means for releasing the dry air into a mixture contained in the separation tank, An oil-water separator, comprising: an air discharging means for allowing air in the tank to escape to the outside. 2. The oil-water separator according to claim 1, wherein a reflux path for once leading the mixed liquid in the separation tank to the outside and returning the mixed liquid to the separation tank again is formed. An oil-water separation device comprising a heating device for heating a mixed liquid under reflux. 3. The oil-water separation device according to claim 2, wherein a filter for removing impurity particles or large water droplet particles contained in the mixture is provided in the reflux path. . 4. The oil-water separation device according to claim 1, wherein the foam generating means is constituted by a structure in which a large number of bowl-shaped bodies made of a sintered metal having a microporous structure are arranged in a protruding state. An oil-water separation device, wherein dry air is discharged into a mixture through a microporous structure.