JP2007160264A - Oil/water separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil/water separator capable of sufficiently reducing oil concentration in drainage by circulating fine oil particles in oily water through fiber materials, preferably cotton wool which is compressed to fill a tank, and further making them pass through a fine mesh filter, and also reducing burden of maintenance. <P>SOLUTION: The water W to be treated containing oil is treated by getting oil particles B separated by a coarse particle board 6 in a first pre-treatment tank 1, and the oil content further separated by a coarse particle filter 7 in a second pre-treatment tank 2. The treated water from which the oil content is coarsely separated is further treated by getting fine oil content removed by an exchangeable cartridge 3A for oil adsorption in a first tank 3, and ultrafine oil particles removed by a fine mesh filter A of 0.1-5 microns in a second tank 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, bilge water containing oil generated in the engine room of a ship or sewage containing oil generated in a factory or the like is separated in advance for environmental protection when discharged to the outside. The present invention relates to a suitable oil-water separator.

Conventionally, oil mixed in water has been separated by a gravity separation method based on a difference in specific gravity between oil and water. And by passing the water channel provided with the parallel plate and the filter, the oil particles are agglomerated and separated by increasing the floating speed.
However, when surfactants and fine dust are mixed in the oil / water mixture, the oil particles become smaller, the difference in specific gravity between water and oil particles becomes smaller, and the floating speed of the oil particles becomes slower. There is a problem that it becomes difficult to separate the oil particles due to the difference. In addition, if only a fine filter is used, there is a problem that clogging occurs and the separation performance deteriorates. And replacement of a clogged filter is not easy because the filter is dirty with oil.
In addition, using a pad or sheet made of fiber material, it is also possible to adsorb the oil floating on the liquid surface or remove the oil by filtration. It is considered difficult to carry out this efficiently.
In general, if oil particles refined by mixing with a surfactant or the like can be removed, the performance of the oil / water separator can be improved and the oil concentration in the waste water can be greatly reduced. With conventional oil-water separators, this fine oil cannot be removed, and when a fine filter is used, frequent filter replacement due to clogging is required, increasing the maintenance burden. Was invited.
JP 2003-24705 A JP 2005-288435 A

  According to the present invention, fine oil particles in oil water are circulated through a fiber material compressed in a tank, preferably absorbent cotton, and then passed through a fine mesh filter, so that the oil concentration in the waste water is sufficiently increased. It is an object of the present invention to provide an oil / water separator that can reduce the maintenance load.

  The present invention includes a first tank that introduces and passes water to be treated containing oil, and captures and separates the oil, and the water to be treated that has passed through the first tank is introduced and passed to capture and separate the remaining oil. The first tank is provided with a replaceable oil adsorbing cartridge in which the fiber material is preliminarily compressed and filled with the fiber material, and the second tank includes a second tank. A fine mesh filter for capturing the remaining oil in the water to be treated is loaded.

  In addition, the present invention is characterized in that the fiber material is absorbent cotton.

  Furthermore, in the present invention, the filter is configured as a membrane separation filter, the mesh of the filter is set to 0.1 to 5 microns, and piping for cleaning the filter by backflow is provided. It is characterized by that.

  The present invention further includes a pretreatment device for reducing in advance the oil content in the treated water with respect to the treated water guided to the first tank, and the pretreatment device initially includes the treated water. A first pretreatment tank that performs coarse separation of oil using a coarse grained plate, and a coarsening filter that guides the water to be treated that has passed through the first pretreatment tank to separate ingots of oil in the treated water. And a second pretreatment tank performed by

  In the oil / water separator according to the present invention, when the water to be treated containing the oil passes through the fiber material compressed and filled in the cartridge in the first tank in the first tank, the fine oil is efficiently captured. Thus, the filtered water that has passed through the first tank in this way can be sufficiently captured by the fine mesh filter in the second tank that passes next.

  The compression filling of the fiber material into the cartridge is performed after the fiber material is wetted in advance, so that the filling density of the fiber material is remarkably increased, thereby passing between the fiber materials. The oil content in the water to be treated is sufficiently captured by the adhesion of the fiber material to the consolidated surface.

  In this way, after the oil is captured to the required level by the fiber material in the first tank, the oil content capturing function in the first tank is immediately recovered by replacing the cartridge filled with the fiber material. You can plan.

  Further, in the oil / water separator according to the present invention, the use of absorbent cotton as the fiber material facilitates and sufficiently performs the operation of wetting the fiber material and compressing and filling it into the oil adsorption cartridge. Since the flow resistance of water to be treated is less than that of other fiber materials, the adsorption and capture of oil by the fiber material (absorbent cotton) can be performed more efficiently and accurately.

  Furthermore, if the fine mesh filter in the second tank is configured as a membrane separation filter, and the filter mesh is set to 0.1 to 5 microns, the filter can easily capture fine oil particles. In addition, since the piping for washing the filter by backflow is provided, the oil content capturing function of the filter can be constantly improved without requiring troublesome replacement of the filter.

  When the oil content in the water to be treated is extremely high, it is desirable to reduce the oil content in the water to be treated in advance prior to the oil / water separation by the first tank and the second tank. In addition, after the first pretreatment tank is subjected to rough separation of the oil in the water to be treated by the coarsening plate, and then the ingot is separated from the water to be treated by the coarsening filter in the second pretreatment tank. The water to be treated is further separated in the first tank and the second tank, and thus the oil in the water to be treated is sufficiently and appropriately separated.

  FIG. 1 is a system diagram schematically showing an oil-water separator as one embodiment of the present invention, FIG. 2 is an explanatory diagram showing the mechanism of oil-water separation, and FIG. 1 (a) shows the mechanism of oil-water separation by adsorption. Explanatory drawing shown, (b) figure is explanatory drawing which shows the mechanism of the oil-water separation by a membrane separation system.

As shown in FIG. 1, the water to be treated W including oil contained in the bilge tank of the ship reduces the oil content in the water to be treated in advance. It comes to be press-fitted with. A large amount of oil in the water to be treated W flowing into the first pretreatment tank 1 is immediately collected upward and discharged from the discharge pipe 1a with valve 1b, and oil having a relatively large particle size is coarsened. 6 is coarsened, and the oil is also discharged from the upper discharge pipe 1 a in the tank 1.
In addition, the code | symbol A in FIG. 1 shows the flow direction of water, B has shown the oil grain typically.

  The first pretreatment tank 1 is provided with oil / water interface sensors 5a and 5b for detecting the oil / water interface in the tank.

  As described above, in the first pretreatment tank 1, oil that flows in a large amount or oil having a relatively large particle diameter is separated. However, in order to separate the oil that remains in the water to be treated, The water to be treated guided from the treatment tank 1 to the second pretreatment tank 2 as a coalescer through the connecting pipe 2c is coarsened and separated by the coarsening filter 7 in the tank 2. The oil thus coarsened is discharged from a discharge pipe 2a with a valve 2b at the top of the tank.

  The treated water W containing the oil passes through the first pretreatment tank 1 and the second pretreatment tank 2 described above, so that the oil is considerably removed. In this apparatus, the pretreatment is performed in the second pretreatment tank 2. Since the treated water is further subjected to the removal process of fine oil particles, it is sequentially fed to the first tank 3 and the second tank 4.

That is, the water to be treated that has passed through the outlet filter 7a of the second pretreatment tank 2 is guided to the top of the first tank 3 via the connecting pipe 3a and the valve 8, and is used for oil exchange that can be exchanged in the first tank 3. In the cartridge 3A, as shown in FIG. 2A, fine oil particles B are adsorbed and removed.
Then, the water to be treated is introduced into the second tank 4 through the first valve 3V at the bottom of the first tank 3 and the second valve 4V at the bottom of the second tank 4.

  Then, the ultrafine oil particles B contained in the water to be treated are captured and removed by the fine mesh (0.1 to 5 micron) filter 4A inside the second tank 4 as shown in FIG. 2 (b). Is called.

The replaceable cartridge 3 </ b> A in the first tank 3 is preliminarily compressed and filled with moisture contained in a fiber material. Absorbent cotton is preferably used as the fiber material.
The filter 4A in the second tank 4 is provided with means for detecting the degree of clogging of the filter 4A with a flow meter or the like.

Then, a washing water introduction pipe 13 is connected to the discharge pipe 10 connected to the top of the second tank 4 via a switching valve 12 as a pipe for washing the filter 4A by backflow. Further, a drain pipe 11 for discharging cleaning water is connected to a pipe 11a between the first valve 3V and the second valve 4V. In this way, the fine mesh filter 4A is cleaned by backflow inside the second tank 4.
Instead of providing the switching valve 12 and the cleaning water introduction pipe 13, a drain pump may be simply provided in the drain pipe 10.

  As shown in FIG. 1, discharge pipes 1d and 2d with valves 1e and 2e for draining water containing heavy impurities are connected to the bottoms of the first pretreatment tank 1 and the second pretreatment tank 2, respectively. Has been. Reference numeral 9 denotes a connecting flange.

  In the oil / water separator of the above-described embodiment, when the water to be treated W containing oil passes through the fiber material compressed and filled in the cartridge 3A in the first tank 3 in the first tank 3, the fine oil content is reduced. The filtered water that has passed through the first tank 3 in this way is sufficiently trapped by the fine mesh filter 4A in the second tank 4 that passes next. It will be removed.

  Then, the compression filling of the fiber material into the cartridge 3A is performed after the fiber material is wetted in advance, so that the filling density of the fiber material is remarkably increased, thereby passing between the fiber materials. Adsorption and capture of oil in the water to be treated W is sufficiently performed by adhering to the compacted surface of the fiber material.

  In this way, after the oil is captured by the fiber material in the first tank 3 to the required level, the oil content capturing function in the first tank 3 is immediately replaced by replacing the cartridge 3A filled with the fiber material. Recovery can be achieved.

  Further, in the oil / water separator of this embodiment, the use of absorbent cotton as the fiber material facilitates and sufficiently performs the operation of wetting the fiber material and compressing and filling it into the oil adsorption cartridge 3A. Since the absorbent cotton has less flow resistance of the water to be treated than other fiber materials, the oil material can be more efficiently adsorbed and captured by the fiber material (absorbent cotton).

  Furthermore, the fine mesh filter 4A in the second tank 4 is configured as a membrane separation type filter, and the mesh of the filter 4A is set to 0.1 to 5 microns. Since the filter 4A is easily removed and piping for washing the filter 4A by backflow is provided, the oil trapping function of the filter 4A can be constantly improved without the need for troublesome replacement of the filter 4A. I can leave.

  When the oil content in the water to be treated is remarkably high, it is desirable to reduce the oil content in the water to be treated in advance prior to the oil / water separation by the first tank 3 and the second tank 4. In the first pretreatment tank 1, the oil content in the water to be treated W is roughly separated by the coarsening plate 6, and then the agglomeration of the oil in the water to be treated is performed by the coarsening filter 7 in the second pretreatment tank 2. After the separation, the water to be treated W is further separated in the first tank 3 and the second tank 4, and thus the oil in the treated water is sufficiently and appropriately separated. Will come to be.

1 is a system diagram schematically showing an oil-water separator as one embodiment of the present invention. It is explanatory drawing which shows the mechanism of oil-water separation, (a) A figure is sectional drawing which shows the mechanism of oil-water separation by adsorption, (b) Figure is sectional drawing which shows the mechanism of oil-water separation by a membrane separation system.

Explanation of symbols

1 First Pretreatment Tank 1a Discharge Pipe 1b Valve 1d Discharge Pipe 1e Valve 2 Second Pretreatment Tank 2a Discharge Pipe 2b Valve 2c Connection Pipe 2d Discharge Pipe 2e Valve 3 First Tank 3A Oil Content Adsorption Cartridge 3a Connection Pipe 3V First Valve 4 Second tank 4A Filter 4V Second valve 5a, 5b Oil / water interface sensor 6 Coarse grain plate 7 Coarse grain filter 7a Outlet filter 8 Valve 9 Flange for connection
10 discharge pipe
11 Drain pipe
11a Piping
12 Switching valve
13 Washing water introduction pipe A Water flow direction B Oil grain W Water to be treated

Claims (4)

  A first tank that introduces and passes through the water to be treated containing oil and captures and separates the oil, and a second tank that introduces and passes the water to be treated that has passed through the first tank and captures and separates the remaining oil. An oil-adsorbing cartridge in which moisture is preliminarily contained in the fiber material and compressed and filled with the fiber material, and the second tank is provided with a replaceable water in the first tank. An oil-water separator, which is equipped with a fine mesh filter for capturing the remaining oil.   The oil-water separator according to claim 1, wherein the fiber material is absorbent cotton.   The filter is configured as a membrane separation filter, the mesh of the filter is set to 0.1 to 5 microns, and piping for cleaning the filter by backflow is provided. The oil-water separator according to claim 1 or 2. A pretreatment device is provided for preliminarily reducing the oil content in the treated water with respect to the treated water guided to the first tank, and the pretreatment device first performs rough separation of the oil content in the treated water. A first pretreatment tank that uses a coarse grained plate and a second pretreatment that guides the water to be treated that has passed through the first pretreatment tank and that separates the agglomerates of oil in the treated water using a coarse filter. The oil-water separator according to any one of claims 1 to 3, wherein the oil-water separator is composed of a tank.

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