JPS6151930B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an oil-water separator that separates, removes, and purifies oil from oil-containing wastewater discharged from machine factories, gas stations, metal surface treatment factories, food processing factories, and the like. Traditionally, this device has been used to recover oil from oil-containing wastewater, using the difference in specific gravity between oil and water without using power.
Furthermore, an oil/water separator is known in which oil is floated and separated by a water level difference, and this apparatus is constructed as shown in FIG. That is, an inlet 1 for introducing oil-containing wastewater stored in a pre-receiving tank (not shown);
A first separation chamber 2, a second separation chamber 3 with an overflow hole 31, a coarsening device 4 filled with fibrous material such as glass wool lock or Raschig ring, a third separation chamber 5, and a steel plate. It consists of a plurality of inclined plates 6, a fourth separation chamber 7, an adsorption chamber 8, and a discharge port 9. Note that the second separation chamber 3 and the adsorption chamber 8 are connected by a pipe 10 for providing a water level difference. The conventional oil-water separator configured as described above has a drawback in that the position of the adjustment plate 32 of the overflow hole 31 must be adjusted depending on changes in the water level. Further, it requires a complicated structure such as a coarsening device 4 and an adsorption chamber 8 provided with an adsorbent, which has the disadvantage of increasing manufacturing and maintenance costs. The present invention has been devised to solve the above problems, and the oil/water separator of the present invention will now be described in detail based on the drawings. FIG. 2 is a perspective view of the entire oil-water separator according to an embodiment of the present invention, FIG. 3 is a front view of the oil-water separator according to the present invention, FIG. an inlet 1 for introducing oil-containing wastewater stored in a tank (not shown), a first separation chamber 2, a second separation chamber 3, a first
oil collection tank 4, third separation chamber 5, inclined plate 6, fourth
It consists of a separation chamber 7, a fifth separation chamber 8, a second oil collection tank 9, and a discharge port 10. Each partition wall of the first separation chamber 2, first oil collection tank 4, fifth separation chamber 8, and second oil collection tank 9 has an overflow hole 3.
1, 32, 41, 81, and 91 are drilled, and a net 11 is stretched over these overflow holes. These nets 11 are made of fibers of fluorocarbon resin such as polytetrafluoroethylene or silicone resin formed into a net shape, or metal nets coated with these resins, and overflow holes 31, 32 are used. , 81 are preferably of 30 to 120 mesh, and the overflow holes 41 and 91 are preferably of 120 to 150 mesh. Further, the inclined plates 6 are made of the same material as the net 11 and have a mesh size of 20 to 40, and are formed by stacking a plurality of them in parallel at regular intervals. The fluororesin or silicone resin of the net 11 and the inclined plate 6 is lipophilic and hydrophobic, and thus has the property of allowing only oil to pass through. Note that the second separation chamber 3 and the fourth separation chamber 7 are connected by a pipe 13 for providing a water level difference. To explain the oil-water separation process in the oil-water separator of the present invention configured as described above, oil-containing wastewater is separated by the water level difference between the inlet 1 and the outlet 10.
Flows from upstream to downstream. The oil-containing wastewater supplied from the inlet 1 is separated and floated to the surface in the first separation chamber 2 due to the difference in specific gravity between water and oil.
and enters the second separation chamber 3 through the overflow hole 31. The water containing particulate oil that has not separated and floated to the surface sneaks under the lower end of the second separation chamber 3, enters the third separation chamber 5, rises, and flows diagonally downward between the net-shaped inclined plates 6. At this time, the oil becomes coarse particles as it passes between the inclined plates 6 and rises, floats to the upper part of the third separation chamber 5 according to Stokes' principle, passes through the overflow hole 32, and flows into the second separation chamber 3. flows into. The oil that has flowed into the second separation chamber 3 from the first separation chamber 2 and the third separation chamber 5 in this way passes through the overflow hole 41 and is stored in the first oil collection tank 4 . Next, the oil-containing wastewater flowing down the inclined plate 6 is transferred to the partition plate 1
2 and flows into the fourth separation chamber 7.
The oil-containing wastewater that has flowed into the fourth separation chamber 7 is separated into oil and water, and the oil that has floated to the surface passes through the overflow hole 81 and flows into the fifth separation chamber 8, and further passes through the overflow hole 91. The oil is then stored in the second oil collection tank 9. Finally, the water passes through the lower end of the fifth separation chamber 8 and exits through the outlet 1.
Ejected from 0. Although the oil is removed in the above manner, the overflow hole 3
1, 32, 41, 81, 91 and the net 11 of the inclined plate 6 will not be clogged by anything other than dirt and can be used for a long period of time. There is no need to replace it unless it breaks, which is extremely advantageous in terms of maintenance. Note that most of the dust is usually removed in the pre-receiving tank. Next, examples will be shown in which the oil-water separator of the present invention was used. Example 1 After filling the oil-water separator of the present invention with oil-free water and adjusting the water level, compressor drain wastewater was passed through as raw water at a rate of 1 m ³ /hr,
The oil concentration in the treated water was measured 1 hour and 50 hours after water flow at a temperature of 20°C. For the overflow hole nets of the first and fifth separation chambers, polytetrafluoroethylene fibers of 10, 30, 60, and 150 mesh were used alternately. The inclined plate nets were all made of 30 mesh polytetrafluoroethylene fibers. The results are shown in the table below.

[Table] Example 2 The oil concentration in the treated water was measured under the same conditions as in Example 1 using a silicone resin fiber net.
The results are shown in the table below.

[Table] As is clear from the above results, the oil-water separator of the present invention does not increase the oil concentration in the treated water even when operated continuously for a long time. The mesh size of each separation chamber is optimally between 30 and 150 meshes; if the mesh size is more than 150 meshes, the oil concentration in the treated water will not increase dramatically, but it will become clogged with very fine particles. There is a risk. Further, it is preferable to use a mesh of the overflow hole of each oil collection tank that is finer than that of the overflow hole of the separation chamber, as described above, on the condition that only oil passes through and water does not pass through.
The net of the inclined plate preferably has a coarse mesh of 20 to 40 mesh in order to coarsen the oil as much as possible and separate and float it. As explained above, according to the oil-water separator of the present invention, there is no need to adjust the adjustment plate of the overflow hole according to changes in water level as in the conventional case, and the net itself is a filter that separates oil and water. It is extremely advantageous in terms of maintenance and management, since it is designed to function as a system. In addition, the inclined plate that separates oil and water and coarsens the oil is formed into a net shape, which eliminates the need for a coarsening device as in the past, resulting in superior effects such as manufacturing advantages. It is played.

[Brief explanation of the drawing]

FIG. 1 is a transparent front view showing a conventional oil-water separator, FIG. 2 is a perspective view showing an embodiment of the oil-water separator of the present invention, and FIG. 3 is a transparent front view. FIG. 4 is a plan view. 1...Inlet, 2, 3, 5, 7, 8... Separation chamber,
4.9...oil collection tank, 6...slanted plate, 10...discharge port,
11...net, 31, 32, 41, 81, 91...
Overflow hole.

Claims (1)

[Claims] 1. An oil-water separator in which a flow is generated due to a water level difference between the inlet and the outlet of oil-containing wastewater, which includes a plurality of oil-water separation chambers and a plurality of oil collection tanks arranged in parallel from the upstream side to the downstream side. A net made of fluororesin or silicone resin is stretched over the overflow holes drilled in the oil/water separation chamber and the oil collection tank, and the plurality of inclined plates are connected to the net. An oil-water separator characterized by being formed of.