JP2691118B2 - Closed pressure oil-water separator using electrolysis - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a closed pressurization type oil-water separator using an electrolysis method related to bilge treatment containing oil generated in an engine room of a ship, and aluminum as a sacrificial electrode. The present invention provides a means suitable for separating and removing oil in wastewater by the electrolytic floating separation method.

[0002]

2. Description of the Related Art In the electrolytic levitation separation method using aluminum as a sacrificial electrode, the oil content in the waste water is aggregated by the produced aluminum hydroxide, and the levitation separation is carried out by the bubbles generated at the same time. Since it is often installed under the waterline, it has a closed and pressurized structure.

When the electrolytic levitation separation method is used in the pressure vessel, the bubbles generated by electrolysis are dissolved in the liquid according to Henry's law, and as a result, the amount of bubbles required for levitation separation of flocs is insufficient. However, without floating, the amount of flocs that flow out while containing oil increases, and the separation efficiency decreases. In general, regardless of whether it is a pressure type or an open type,
The flocs floated and separated by the electrolytic flotation method had a high water content, and it was difficult to discard them without dehydration treatment.

[0004]

In view of the above points, in the present invention, in order to effectively utilize the electrolytic levitation separation method under pressure, it is possible to prevent the bubbles generated by electrolysis from being dissolved, and at the same time, to collect the flocs. It is an object of the present invention to provide means for improving the oil-water separation performance by simplifying the above.

[0005]

In order to achieve the above-mentioned object, the present invention comprises an oil / water supply pump and an oil / water separator, wherein the oil / water separator is a parallel separation plate tank as a pretreatment stage, It is composed of an electrolysis tank and a flotation separation tank as a post-treatment process, and a pipe is provided between the top of the flotation separation tank and the suction side of the oil water supply pump, and flocs accumulated on the top of the flotation separation tank by electrolysis The bubbles are introduced into the parallel separation plate tank as the pre-treatment process.

[0006]

With the configuration of the present invention, the flocs and bubbles generated in the electrolytic cell and accumulated on the top of the floating separation tank are introduced into the parallel separation plate tank, so that the separation efficiency of the parallel separation plate tank is improved. , The load in the post-treatment process can be reduced, and moreover,
Since the bubbles are returned to the parallel separation plate tank, the solubility of the bubbles is maintained in a saturated state, the separation efficiency can be prevented from lowering in the post-treatment process, and the overall separation efficiency is improved. Can be achieved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a parallel separation plate tank. In this parallel separation plate tank 1, bilge sucked from a bilge suction pipe 3 is pressurized from an oil water supply pump 4 connected to a supply pipe 5 through a supply hole 1a. Supplied. In the parallel separation plate tank 1,
A plurality of substantially parallel separation plates 2 are arranged side by side, and in the bilge supplied under pressure, the separation plate 2 roughly separates oil. This separated oil is stored in the upper part of the parallel separation plate tank 1.

An oil level detector 6 is provided on one side and an oil discharge pipe 16 connected to an oil discharge valve 7 is provided on the other side above the parallel separation plate tank 1 in which the separated oil is stored. The position of the oil surface accumulated in the parallel separation plate tank 1 is detected by the oil level detector 6, and when the position of the oil surface accumulated in the parallel separation plate tank 1 reaches a predetermined height, the oil level detector 6 The oil drain valve 7 is opened in response to a signal from and the oil is drained out of the parallel separation plate tank 1 by the oil drain pipe 16.

An electrolytic cell 8 is formed below the separation plate 2 of the parallel separation plate tank 1 through a communication hole 1b. In the electrolytic cell 8, an anode plate 9 and a cathode plate 10 made of a plurality of aluminum are juxtaposed at appropriate intervals, and the anode plate 9 and the cathode plate 10 are provided outside the electrolytic cell 8. The arranged power supply device 11 is connected. Therefore, the bilge roughly separated in the parallel separation plate tank 1 is electrolyzed in the electrolysis tank 8 by the direct current from the power supply 11 flowing to the anode plate 9 and the cathode plate 10.

Above the parallel separation plate tank 1 and the electrolytic cell 8,
Flotation separation tank 13 connected to connecting pipe 12 from electrolysis tank 8
The flotation tank 13 has a function that flocs of aluminum hydroxide produced in the electrolysis tank 8 aggregate the minute oil droplets in the bilge to float and separate the flocculation tank 13. An outboard discharge pipe 14 for discharging the bilge from which oil has been separated and discharged to the outside of the ship is provided at a lower portion thereof, and a flock discharge pipe 15 connected to the bilge suction pipe 3 is provided at an upper portion thereof. Reference numeral 17 denotes an automatic air vent valve, which prevents bubbles from coalescing and forming an air reservoir at the top of the flotation / separation tank 13.

The bilge and aluminum hydroxide flocs and bubbles that have been electrolyzed in the electrolytic bath 8 are mixed in the connecting pipe 12 and flow into the floating separation bath 13. The minute oil droplets in the bilge are aggregated / float-separated by the action of aluminum hydroxide and bubbles, and are collected in the upper part of the flotation / separation tank 13. On the other hand, the bilge from which oil has been separated and removed passes through the outboard discharge pipe 14 and is discharged to the outside of the ship.

The flocs accumulated in the upper part of the floating separation tank 13 are discharged by a floc discharge pipe 15 connected to the bilge suction pipe 3, and mixed with bilge by the oil / water supply pump 4 via the bilge suction pipe 3. Parallel separation plate tank 1
It is supplied under pressure.

Floating separation tank 1 produced in electrolysis tank 8
A considerable amount of activity remains in the flocs accumulated at the top of No. 3, and the bubbles generated by electrolysis are also present in the flocs alone or alone. Such flocs and bubbles
By mixing with the bilge by the oil / water supply pump 4 through the bilge suction pipe 3 and being introduced into the parallel separation plate tank 1, the following effects are produced.

The separation efficiency of the oil component in the parallel separation plate tank 1 as the first-stage treatment is improved, and the load on the electrolytic tank 8 and the floating separation tank 13 as the second-stage treatment can be reduced. In Table 1,
The data which compares the case of this invention which returns a floc with the case where a floc is not returned are shown.

[Table 1]

In the case of the pressure type, as is clear from Henry's law, the bubbles generated by the electrolytic method dissolve in the liquid and the electrolytic flotation separation efficiency decreases, but by returning the flocs to the pretreatment step, Since the solubility of the bubbles is maintained in a saturated state, it is possible to prevent the separation efficiency from being lowered in the subsequent process.

Since flocs, which are difficult to recover by themselves, can be recovered as a mixture with the oil separated in the pretreatment process, there is no problem of excessive water content, and the waste oil treatment is simplified. Since the separation efficiency is improved as a whole, the oil-water separator can be downsized.

According to the present invention, as described above, the parallel separation plate tank 1 is used.
The oil particles in the bilge that have flowed into the tank are coalesced by the flocs of aluminum hydroxide to promote the coalescence of the oil particles, thereby promoting the floating separation rate. Further, as in the above description, the flock accumulated in the upper part of the parallel separation plate tank 1 along with the oil content is detected by the oil level detector 6 to detect the oil level, and the drain valve 7 is automatically opened to be discharged to the outside. Also, the bubbles that have flowed into the parallel separation plate tank 1 together with the flocs are dissolved in the bilge,
It has a function of eliminating the dissolution of the generated bubbles due to the electrolysis under the aforementioned pressure.

[0018]

In the constitution of the present invention, a floc containing oil and air bubbles floated and separated by the electrolysis method in the post-treatment step,
By introducing to the parallel separation plate tank in the pre-treatment process, the oil-water separation efficiency in the parallel separation plate tank is increased, and at the same time, the dissolution of bubbles, which was a drawback of the electrolytic levitation separation method under pressure,
It can be prevented by making it saturated in the first-stage treatment stage, and the oil-water separation efficiency in the second-stage treatment process can be improved. Also, with regard to the collection of flocs, since the oil is discharged together with the roughly separated oil, the collection becomes easier.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an oil / water separator according to the present invention.

[Explanation of symbols]

 1 Parallel Separation Plate Tank 1a Supply Hole 1b Communication Hole 2 Plural Separation Plates 3 Bilge Suction Pipe 4 Oil Water Supply Pump 5 Supply Pipe 6 Oil Level Detector 7 Oil Discharge Valve 8 Electrolysis Tank 9 Anode Plate 10 Cathode Plate 11 Power Supply 12 Connection pipe 13 Flotation separation tank 14 Outboard discharge pipe 15 Flock discharge pipe 16 Oil drain pipe 17 Automatic air vent valve

Claims (1)

(57) [Claims] 1. An oil / water supply pump and an oil / water separator, wherein the oil / water separator comprises a parallel separation plate tank as a pretreatment step, an electrolytic cell and a flotation separation tank as a posttreatment step, and A pipe is provided between the top of the flotation separation tank and the suction side of the oil / water supply pump, and the flocs and bubbles accumulated at the top of the flotation separation tank due to electrolytic treatment are introduced into the parallel separation plate tank as the pre-treatment process. A closed pressurized oil-water separator using an electrolysis method, which is characterized in that