JP2667412B2 - Oil-water separator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an oil-water separation device using oil-containing wastewater using a ceramic filter. [Prior Art] Oil-containing wastewater to be subjected to oil-water separation is, for example, a floating oil in which coagulated oil droplets are aggregated on a liquid surface, a dispersed oil in which relatively large oil droplets are mixed and dispersed in water, Or, it mainly contains emulsified oil emulsified by a surfactant or an active aid, and is discharged in all fields of industry. For example, wastewater in the technical fields of petroleum refining, steel rolling, textile processing, food production, and machining are also typical oil-containing wastewaters. These oil-containing wastewaters are treated by a so-called membrane method, such as a reverse osmosis method, a marginal excess method, or a precision excess method, as one of the treatment methods. [Problems to be Solved by the Invention] The membrane method has a number of advantages such as being particularly effective for emulsifying waste liquids, but has a problem in preventing contamination of the membrane surface or removing contamination generated on the membrane surface. There is still room for development. Also, when the material of the membrane is a polymer compound, the solvent resistance to water and oil cannot be ignored, so it is not suitable for oil-water separation of an emulsion of water and oil. Hurt. The present invention has been made in view of the above points, and an object of the present invention is to provide a filter in which the material does not change even when immersed in water and oil and the filter surface is not damaged by sludge. It is an object of the present invention to provide an oil-water separation device capable of removing contamination generated in the oil-water separation. [Means for Solving the Problems] According to the present invention, the object is to provide a container and both ends for partitioning the interior of the container into an inner first chamber and a first outer second chamber. Are each liquid-tightly fixed to the inner surface of the container, is a filter for filtering the oil-containing wastewater, the pore diameter of the pores of the innermost layer is 0.05μm ~ 1.8μm,
A filter having a cylindrical three-layer structure in which the innermost layer thickness is 10 μm to 40 μm and the pore diameter of the pores increases from the inside to the outside; An inlet provided in the container at one end of the filter to introduce the oil-containing wastewater into one chamber, and an inlet provided at the other end of the filter to discharge the oil-containing wastewater from the first chamber. A first outlet provided, and a second outlet provided in the container for discharging a filtrate of the oil-containing wastewater filtered by the filter from the second chamber. It is achieved by the oil-water separation device. [Function] According to the apparatus of the present invention, since the filter is made of porous ceramics made of alumina having a purity of 99% or more, the filter has excellent water resistance and oil resistance, and the filter has a destructive strength. Because of its high value, it is possible to prevent the filter surface from being damaged by sludge of oil-containing wastewater containing iron, activated carbon, a lubricant, and the like, and it is possible to perform filtration even at a high temperature not exceeding the oil ignition point. In addition, the apparatus of the present invention is configured such that oil-containing wastewater flows from an inlet provided in the container at one end of the filter to a first outlet provided in the container at the other end of the filter. Thus, a stream of oily wastewater may be formed along the filter surface defining the first chamber,
As a result, the oil-impregnated wastewater introduced into the first chamber can wash away the contamination deposited on the filter surface defining the first chamber toward the first discharge port, and simultaneously filter the oil-impregnated wastewater and wash the filter. You can also do Further, in the filter according to the present invention, the first chamber is provided inside the filter, the innermost layer has a pore diameter of 0.05 μm to 1.8 μm, and the innermost layer has a thickness of 10 μm to 40 μm.
μm and a cylindrical three-layer structure in which the pore size increases from the inside to the outside, reducing the thickness of the innermost layer where the pore size is small to reduce clogging and increase filtration resistance. The oil and water can be efficiently separated by pressing, and the outer portion of the filter can support while protecting the innermost layer. The oil-containing wastewater introduced into the apparatus of the present invention is 0.2 to 5 kg / cm ²
Preferably, the flow rate of the oil-containing wastewater along the filter surface can be suitably maintained, and the excess amount of the oil-containing wastewater can be appropriately maintained. Further, at the inlet side of the apparatus of the present invention, one or more pretreatment oil / water separation filters having a larger pore diameter may be provided, whereby the pretreatment oil / water separation filter has a relatively large diameter. Emulsions, oils and sludge can be removed, and as a result, clogging and contamination of the filter of the device of the present invention can be reduced. In the device of the present invention, an emulsion having a relatively small diameter is preferably removed. As the oil / water separation filter for pretreatment, a ceramic cylindrical multilayer filter is preferable, and the pore diameter of the innermost pores is small.
Those having a thickness of 10 to 100 μm are particularly preferable. Further, when a filter having a large amount of solids is used, a filter made of a ceramic foam having a three-dimensional network structure having continuous pores having a pore diameter of 0.1 to 5 mm in front of the oil / water separation filter for pretreatment, or a mesh having a pore size of 0.
Overefficiency can be increased by providing a 5 to 5 mm net. Further, the filter of the present invention may be backwashed with a washing liquid. At this time, it is preferable to use caustic soda as the cleaning liquid. The filter of the device of the present invention may be a polygonal prism, preferably a hexagonal prism, provided with a plurality of through-holes along the longitudinal direction of the prism, preferably through-holes having a circular cross section. [Specific Examples] Hereinafter, the present invention will be described in more detail using preferred specific examples shown in the drawings. In the figure, a liquid container 1 is filled with emulsified oil-containing wastewater. The container 1 is connected to an inlet 4 provided at one end of a cylindrical filter container 3 having both ends closed by an appropriate pipe 2. A pump 5 for supplying oil-containing wastewater to the inlet 4 is provided. Between the pump 5 and the inlet 4, a primary oil / water separation filter 6 made of a spongy substance for removing an emulsion having a relatively large diameter, oil content, and sludge contained in the oil-containing wastewater supplied by the pump 5. Is provided. Inside the container 3, an alumina tubular filter 7 having a pore diameter of 0.2 μm is accommodated, and both ends of the filter 7 are fixed to both end surfaces of the container 3 in a liquid-tight manner. The filter 7 is configured such that the inside of the container 3 is a chamber 8 outside the filter 7.
And a chamber 9 inside the filter 7. The chamber 9 communicates with the inlet 4 at one end surface of the container 3. Container 3
A discharge port 10 is provided on the other end surface of the chamber, and the chamber 9 is provided with a discharge port.
It also communicates with 10. The outlet 10 is connected to the container 1 by a suitable pipe 11. A discharge port 12 communicating with the chamber 8 is provided at a lower portion of the container 3. Hereinafter, the operation of the device of the present invention will be described. The pump 5 removes the oil-containing wastewater in the container 1 from the filter 6.
The filter 6 removes an emulsion having a relatively large diameter, oil, and sludge in the oil-containing wastewater. The oil-containing wastewater that has passed through the filter 6 is supplied to the chamber 9 through the inlet 4.
And then a relatively small emulsion is passed through the filter 7. This excess liquid is discharged from the chamber 8 through the discharge port 12. On the other hand, a part of the oil-containing wastewater introduced into the chamber 9 from the inlet 4 is discharged as a concentrated liquid from the container 3 through the outlet 10 and returned to the container 1 through the pipe 11. In the chamber 9, the oil-containing wastewater flows along the inner peripheral surface of the filter 7 in the longitudinal direction of the filter 7. The filter 7 can be washed away. FIG. 2 shows the result of using the waste liquid in the electric component manufacturing process by electric discharge machining as the oil-containing waste water and passing the waste liquid by the apparatus of this specific example. Note that the liquid of this specific example is emulsion water having a total organic carbon (TOC) of 2940 ppm, and the amount of water passing through the filter 7 is 100 / m ² -h. The emulsion has a small particle size immediately after the generation of the oil-containing waste liquid, and when the number of days is increased, the small emulsion becomes large to some extent. According to FIG. 2, when the TOC value of the excess liquid of the liquid of the present embodiment is passed through the 0.2 μm filter immediately after the generation of the oil-containing wastewater by using the apparatus of the present embodiment (see FIG. 2). The line 51) is 720 ppm, and when it passes through the 0.1 μm filter (line 52 in FIG. 2), it is 590 ppm, 2
2 days after passing through a 0.2 μm filter (line 5 in FIG. 2)
3) can be 600 ppm or less. Referring to FIG. 3, a three-stage filter device using one embodiment of the present invention will be described. The liquid container 11 is filled with emulsified oil-containing wastewater. This vessel 11 is connected to one end of a cylindrical filter vessel 12 having both ends closed by an appropriate pipe 13, and supplies oil-containing wastewater in the vessel 11 to the vessel 12 in the middle of the pipe 13. A pump 14 for performing the operation is provided. Inside the container 12, a cylindrical filter 15 made of ceramic foam having a three-dimensional network structure having a pore diameter of 0.5 mm is accommodated, and one end of the filter 15 is connected to the pipe 13. The other end of the filter 15 is connected to the container 11 by an appropriate pipe 16. The first excess liquid passed by the filter 15 is supplied to the liquid container through the outlet 17.
Guided to 18. The liquid container 18 is a cylindrical filter container having both ends closed.
One end of the pipe 19 is connected by a suitable pipe 20, and in the middle of the pipe 20, the first excess liquid in the vessel 18 is supplied to the vessel 19.
A pump 21 is provided for supplying to the pump. Inside the container 19, a tubular filter 22 made of alumina having a pore diameter of 10 to 100 μm is accommodated. The structure and function of the container 19 and the filter 22 are the same as those of the apparatus shown in FIG. A part of the first excess liquid introduced into the filter 22 becomes a concentrated liquid and is returned to the container 18 through an appropriate pipe 23. The second excess liquid passed by the filter 22 is led to the liquid container 25 through the outlet 24. The liquid container 25 is a cylindrical filter container having both ends closed.
26 is connected to one end of the container 26 by a suitable pipe 27. In the middle of the pipe 27, the second excess liquid in the container 25 is supplied to the container 26.
A pump 28 is provided for supplying to the pump. Inside the container 26, an alumina tubular filter 29 having a pore diameter of 0.1 to 1.8 μm is accommodated. The structure and function of the container 26 and the filter 29 are the same as those of the apparatus shown in FIG. Part of the second excess liquid introduced into the filter 29 becomes a concentrated liquid and is returned to the container 25 through an appropriate pipe 30. The third excess liquid passed by the filter 29 is transferred to the container 26 via the outlet 31. Emitted from. The effect of the device shown in FIG. 3 will be described with reference to FIGS. 4 and 5. In the graph of FIG. 4, the horizontal axis indicates the particle size of the passed solids, and the vertical axis indicates the cumulative percentage of solids. Solid line 41 is data in filter 29, dashed line 42
Is the data in the filter 22, and the dashed line 43 is the filter 15
In the data. According to FIG. 4, the solid content having a particle size of 0.5 mm or more can be removed by the filter
It can be seen that the solid content having a particle size of 10 μm or more can be removed. According to another measurement, no solid is detected in the third excess liquid discharged from the discharge port 31. In the graph of FIG. 5, the horizontal axis indicates overtime, and the vertical axis indicates excess. The solid line 44 is the excess data of the apparatus of FIG. 1, and the broken line 45 is the filter 29 of the apparatus of FIG.
It is the data of excess amount of. According to FIG. 5, a three-stage filter such as the device of FIG. 3 can remove large solids from oil-containing wastewater in advance by a first-stage filter and a second-stage filter. The excess amount of the filter is larger than that of the excess device which does not perform the pre-processing as in the device of FIG. Further, in the apparatus shown in FIG. 1, the filter 7 is a 0.2 μm filter having a pore size of 0.2 μm and a pore size of 0.2 μm.
For both cases with a 1 μm 0.1 μm filter,
FIG. 6 shows the results obtained by mixing a stock solution obtained by mixing a polishing oil, iron as sludge, activated carbon, and a lubricant with water as the oil-containing wastewater, followed by stirring. In FIG. 6, the solid line 54 is
The excess amount by the 0.1 μm filter is shown, and the broken line 55 is 0.2 μm
Indicates an excessive amount due to the filter. The measurement conditions for a 0.1 μm filter are as follows: the temperature of the stock solution is 30 to 41 ° C., and the inlet 4
At 2.1 kg / cm ² G, and the hydraulic pressure at outlet 12 is 0.
45-0.5 kg / cm ² G, the circulation amount of the stock solution is 5100-5200 / h, and the measurement conditions in the case of a 0.2 μm filter are as follows: the stock solution temperature is 32-45 ° C., and the liquid pressure at the inlet 4 is 2.1- 2.3 kg / cm
² G, the liquid pressure at the outlet 12 is 0.4-0.5 kg / cm ² G, and the circulation amount of the stock solution is 4500-5000 / h. According to FIG. 6, compared to the case of the 0.2 μm filter, 0.1
In the case of the μm filter, the excess amount is larger and it can be seen that the filter is not clogged. 0.1μm
This is because, in the case of the filter, the sludge tends to be washed by the stock solution flowing along the inner peripheral surface of the filter 7 without clogging the pores of the filter 7. Incidentally, the 0.1 μm filter has a smaller TOC value of the excess liquid from the outlet 12. [Effects of the present invention] According to the device of the present invention, since the filter is made of porous ceramics made of alumina having a purity of 99% or more, the filter has excellent water resistance and oil resistance, and the filter is broken. Because of its high mechanical strength, it is possible to prevent the filter surface from being damaged by sludge of oil-containing wastewater containing iron, activated carbon, a lubricant and the like, and it is also possible to filter at a high temperature within a range not exceeding the oil ignition point. In addition, the device of the present invention is configured such that the oil-containing wastewater flows from the inlet provided in the container at one end of the filter to the first outlet provided in the container at the other end of the filter. Thus, a stream of oily wastewater may be formed along the filter surface defining the first chamber,
As a result, the oil-containing wastewater introduced into the first chamber can wash away the pollution accumulated on the filter surface defining the first chamber toward the first outlet, and the filter can be washed simultaneously with the filtration of the oil-containing wastewater. You can also do Further, in the filter according to the present invention, the first chamber is provided inside the filter, the pore diameter of the innermost layer is 0.05 μm to 1.8 μm, and the innermost layer thickness is 10 μm to 40 μm.
Since it has a cylindrical three-layer structure in which the pore diameter is μm and the pore diameter increases from the inside to the outside, the thickness of the innermost layer with the fine pore diameter is reduced to increase clogging and filtration resistance. The oil and water can be efficiently separated by pressing, and the outer portion of the filter can support while protecting the innermost layer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cutaway perspective view showing one embodiment of the apparatus of the present invention, FIG. 2 is a graph showing the effect of one embodiment of the apparatus of the present invention, and FIG. FIG. 4 is an explanatory diagram of an application example of one specific example of the device, FIG. 4 is an explanatory diagram of the effect of the device shown in FIG. 3,
FIG. 5 is a graph for comparing the excess amount between one specific example of the device of the present invention and the device shown in FIG. 3, and FIG. 6 is a graph for comparing the effect between the 0.1 μm filter and the 0.2 μm filter. . 3 ... filter container, 4 ... inlet, 7 ... filter,
10,12 …… Outlet.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Mitsumasa Hasegawa               1 South Fuji, Ogakie Town, Kariya City, Aichi Prefecture Toshiba               Ceramics Corporation Kariya Works                (56) References JP-A-62-186908 (JP, A)                 JP-A-62-140609 (JP, A)                 JP-A-62-213817 (JP, A)                 JP-A-56-48213 (JP, A)                 JP-A-60-67991 (JP, A)                 JP-A-63-59315 (JP, A)                 JP-B-59-48646 (JP, B2)                 JP-B-59-25601 (JP, B2)

Claims (1)

(57) [Claims] An oil-impregnated container having both ends liquid-tightly fixed to an inner surface of the container to partition the interior of the container into a first chamber inside and a second chamber outside the first chamber; A filter for filtering wastewater, wherein the pore diameter of the innermost layer pores is 0.05 μm to 1.8 μm, and the innermost layer thickness is 10 μm to 40 μm.
m, and has a cylindrical three-layer structure in which the pore diameter increases from the inside to the outside. The filter is made of porous ceramics made of alumina having a purity of 99% or more. An inlet provided in the container at one end of the filter for introducing wastewater, and a first port provided on the container at the other end of the filter for discharging the oil-containing wastewater from the first chamber. An oil-water separator, comprising: a discharge port; and a second discharge port provided in the container to discharge a filtrate of the oil-containing wastewater filtered by the filter from the second chamber. 2. The pore diameter of the pores in the innermost layer of the filter is 0.07 μm to 1.
2. The device according to claim 1, wherein the thickness is 2 μm. 3. 3. The device according to claim 2, wherein the innermost layer of the filter has a pore diameter of 0.1 [mu] m. 4. The oil-containing wastewater has an innermost layer having a pore diameter of 10 μm to 100 μm.
2. The apparatus according to claim 1, wherein the apparatus is processed by a pre-treatment oil / water separation filter having a size of [mu] m. 5. After the oil-containing wastewater is treated by a ceramic filter having a three-dimensional network structure having a pore diameter of 0.5 mm to 5 mm, the pore diameter of the innermost layer pores is treated by a pretreatment oil-water separation filter having a pore diameter of 10 μm to 100 μm. Apparatus according to claim 1, characterized in that: 6. The apparatus according to claim 1, wherein the filter has a shape of a hexagonal prism, and a plurality of through holes having a circular cross section are provided in a longitudinal direction of the prism.