JP3026508B2 - Apparatus and method for separating components in a mixture comprising an immiscible liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Problems in separating oily substances or hydrocarbons (hereinafter simply referred to as "oil") dispersed in an aqueous solution,
That is, many experts have studied the problems in the case where the insoluble oil layer is totally separated from the aqueous layer in which the oil layer is dispersed, and various techniques have been proposed and used.

Attempting to reduce the minimum amount of oil remaining in the water after separation in the separation process greatly increases the difficulty. This difficulty also increases operating costs.

Known techniques which have been employed up to now are, for example, absorption on active substances (for example activated carbon), distillation, decantation through packed blades, ultrafiltration and centrifugation.

All the techniques described above have the disadvantages of limiting their respective possibilities and are particularly limited when treating the water to be treated in large quantities so as to contain as little residual oil as possible. For example, weight separation is limited, especially when processing very fine emulsions, and can only be used when the specific gravity difference between the aqueous layer and the oil layer is sufficiently large.
Alternatively, thermal separation involves significant energy costs and is not applicable on a large scale. In the case of separating oil from the surface of water, a technique using a membrane has a drawback of low productivity and also has a problem of clogging.

According to current common perception, the presence of oil is detrimental to the environment, water life and the general use of water resources, so treating large volumes of oil-contaminated water is appropriate. It is necessary to restore to an environmental condition. Therefore, new technologies suitable for economical application on a large scale to remove oil from water are needed today for unsolved problems.

The main object of the present invention is to provide a solution to the above technical problem.

Accordingly, the present invention is an apparatus for separating two components, a component having a higher specific gravity and a component having a lower specific gravity, of a liquid mixture composed of a plurality of liquids that are at least partially immiscible. A hollow body, wherein the hollow body is disposed at a lower portion of the hollow body and discharges a component having a higher specific gravity, and a first outlet port is disposed at an upper portion of the hollow body to discharge a component having a lower specific gravity. A second outlet port for providing a mixture to the hollow body between the outlet ports, and the apparatus further comprises an inlet port and a first port. In a device having a filter disposed in the hollow body between the outlet ports, a component having a higher specific gravity is supplied to the hollow body through the first outlet port prior to supplying the mixture through the inlet port. By doing Filter and completely and permanently immersed in the components of larger specific gravity to propose a device having means to ensure the complete absence of air in the filter.

Preferably, one of the plurality of liquids is an aqueous liquid, ie, water or a liquid similar to water, or a liquid suitable for mixing with water, and at least one other is an oily liquid.

Further, the present invention is a method for separating two components, a component having a higher specific gravity and a component having a lower specific gravity, of a mixed liquid composed of a plurality of liquids that are at least partially immiscible. The hollow body is adapted to be performed in the hollow body, and the hollow body is provided at a lower portion of the hollow body to discharge a component having a higher specific gravity, and a first outlet port is provided at an upper portion of the hollow body and has a specific gravity. A second outlet port for discharging the smaller component, and an inlet port disposed in the hollow body between the outlet ports for supplying the mixed liquid into the hollow body; In a method wherein the filter is arranged in the hollow body between the one outlet port, prior to supplying the mixed liquid through the inlet port, the component having a higher specific gravity is introduced into the hollow body through the first outlet port. By supplying The filter is completely and permanently immersed in the component having the higher specific gravity so that no air is present in the filter.The mixture is supplied into the hollow body, and the mixture is supplied to the filter with a hydrostatic head. A method is proposed in which a component having a higher specific gravity is passed through the first outlet port and a component having a lower specific gravity is recovered from a second outlet port.

Other features and advantages of the present invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings. The drawing is a sectional view of a preferred embodiment of the device according to the invention.

As shown in the drawing, the device 1 comprises a stationary hollow body 2
And the hollow body 2 defines a chamber 3. Hollow body 2
Is provided with an inlet port 4 provided on the side for supplying the mixture to be separated, a lower outlet port 5 and an upper outlet port 6 extending laterally. The component (water) having the higher specific gravity of the separated liquid mixture 11 flows out from the lower outlet port 5, and the component (oil) having the lower specific gravity flows out from the upper outlet port 6. In order to increase the efficiency of the device 1 and to make it cheaper, the hollow body 2 is preferably formed from an elongated cylinder as shown and has a circular or rectangular cross section.

The chamber 3 is divided by a filter 7 into an upper chamber 3a and a lower chamber 3b. Filter 7 has inlet port 4 and lower outlet port 6
It is sealed and attached to the wall of the hollow body 2 located therebetween. The filter 7 is attached to the wall surface of the hollow body 2 by any suitable means such as a flange so that no gap is formed between the side surface of the filter 7 and the wall surface of the hollow body 2. The filter 7 comprises a hydrophilic material 8 contained between a pair of wires or a flexible mesh 9, the hydrophilic material 8 preferably comprising short fibers.
Alternatively, the hydrophilic material 8, which is a filtering material, may be accommodated between any other means capable of holding it in place, in which case the liquid must be able to pass through the filter 7. Also, the mesh of the net 9 should be small enough to prevent the passage of the hydrophilic material 8 and at the same time large enough to allow the desired flow of water. The mechanical structure of the filter 7 for supporting the net 9 is formed in a known manner, without impairing and over-packing the hydrophilic material 8 contained in the net 9 with the usual filtration and backflow of water. Must be able to withstand the water pressure created by the The backflow of water is initially used to wash the filter 7 after pretreatment.

According to the inventor, the hydrophilic material 8 is preferably finely ground to a granular form, preferably such that one dimension of the individual grains is larger than the other two dimensions. Has been confirmed. The hydrophilic material 8 is layered or randomly arranged in the filter 7 and is suitable for forming a plurality of microchannels extending almost continuously when immersed in water. Water flows through these fine passages.

According to the invention, the hydrophilic material 8 suitable for forming the bed of the filter 7 is preferably a short fiber of natural fibers (eg cotton, wool, flax, etc.) (hereinafter simply referred to as "fibrils"). )) Or a mixture of fibrils and other natural or synthetic fibers containing polar groups having hydrophilic properties. In particular, materials suitable for this purpose can be formed from spinning waste or fibrous "tufts" that are spun or littered during the spinning operation.

An important feature of the present invention is that the dimensions of the hydrophilic material 8 are formed from fibrils of predetermined dimensions. The size of the fibrils must not be too small. If it is too small, the filter bed of hydrophilic material must be packed, thereby drastically reducing the flow rate of the water flowing through the filter 7. On the other hand, the size of the fibrils must not be too large. If it is too large, a gap will be formed thereby reducing the efficiency of the filter. Thus, the fibrils are preferably
The diameter ranges from 10 to 3,000 μm and the length ranges from 2 to 50 mm.

Since the hydrophilic material 8 must be hydrophilic, plant fibrils such as cotton, flax and hemp and some animal fibrils such as wool are optimal for this purpose. Among the synthetic fibers, fibers made of a derivative of a resin having sufficient polarity can be used, and these resins are, for example, acrylic resin, polyamide resin, cellulose resin, urethane resin, and the like.

The thickness of the layer of hydrophilic material 8 forming the filter 7 ranges, for example, from about 1 cm to 10 cm (preferably 2 to 5 cm). In order to obtain an effective separation at high flow rates, the fibril layer should preferably be kept very flexible. In other words, the fibrils should preferably be so loosely packed that the individual fibrils simply contact each other without excessive compression. Therefore, the porosity in the filled filter 7 (that is, the ratio of the volume of the void in the filter to the volume of the entire filter) is preferably 5 to 80%. Preferably, natural fibrous (eg, cotton) fibrils should be mixed with acrylic or synthetic fibers that do not undergo mechanical changes to water to prevent overfilling of the filter bed. is there. The acrylic or synthetic fibers form an anti-packing agent of natural fibers. The synthetic fibers to be mixed can also be in a "tuft" shape. Instead of such a mixture, the filter 7 can be configured by alternately repeating the natural fibril layer and the synthetic fibril layer. Also, the filter bed can be obtained by nonwoven fabric technology.

Another important advantage of the hydrophilic material 8 of the present invention is that it has chemical resistance in a variety of operating environments and has the potential to be recycled in a harmless manner, for example with composting technology. .

These fibrils can be used in an untreated state so that the fibrils of the hydrophilic material 8 can be produced as spun waste. However, simple pretreatment of the fibrils can also provide a high quality and more uniform filter bed throughout.

The first pretreatment consists of cleaning with surfactants and removing any fats and dressings adhering to the fibrils.
sing), then at 30-40 ° C, 5
It consists of a simple oxidation step with 10% hydrogen peroxide. Due to this oxidizing action, the surface of the fibrils is activated, giving the fibrils great hydrophilic properties. A "water carding" action is then performed which causes the fibrils to become soft and smooth. It is then mixed in a high-speed lodge-type plow mixer after the drying action, so as to obtain a homogeneous mixture of the various fibrils required in the present invention.

According to the separation method of the present invention, the above-described device 1 is used as follows. That is, clean water is first introduced from the lower inlet port 5 so that each gap formed between the fibrils of the hydrophilic material 8 is completely filled, and a water layer is formed above the filter 7 so that the filter 7 Is immersed in water. Continue immersing the filter 7 in clean water until all the air present in the filter 7 has been expelled and the individual fibrils have been completely immersed.

This pretreatment step of the separation method according to the invention is particularly important and must be performed accurately in order for the device 1 to efficiently perform the separation operation of the water / oil mixture 11. In fact,
According to the inventor, the immersed water is present in three substantially different locations. That is, there are water absorbed inside the fibrils, water adhering to the surface of the fibrils, and water crotch between the fibrils adjacent to each other. These form a hydrophilic barrier.

According to the plausible explanation explaining that the device according to the invention operates very efficiently, the characteristics of the filter 7 and the fact that the filter 7 is subjected to sufficient immersion before starting the separating action, A deposited layer of water molecules covering the surface is formed, and these water molecules are strongly bonded to each other and also to the filter 7. Note that this description is merely an example and does not limit the present invention. This deposited layer forms a hydrophilic barrier through which oil droplets contained in the liquid mixture 11 to be separated cannot pass. In fact, water molecules can pass through the hydrophilic barrier, while oil droplets cannot.

Next, the untreated mixed liquid 11 is supplied into the apparatus 1 through the inlet port 4. The mixed liquid 11 is separated into, for example, water (indicated by a broken line in the drawing) and oil (indicated by a small circle in the drawing). For this purpose, the inlet port 4 is provided with a duct and extends into the hollow body 2, the end of the duct in the hollow body 2 having an upwardly conical diffuser 10.
Is provided. Whirlpools may prevent the formation of the above-mentioned water deposits properly, but the diffuser 10 prevents any swirls from reaching the surface of the filter 7. Indeed, with such a configuration, the flow of the untreated mixture 11 in the part facing the filter 7 becomes laminar, in which case it can be from 1 or less to several cm / sec, preferably from 0.1 to 10 c
Maximum speeds up to m / sec are obtained.

The mixture 11 fills the chamber 3, thereby creating a hydrostatic head acting on the filter 7. At this time, the surface height of the mixture 11 is determined by the height of the upper outlet port 6. Preferably, the processing liquid is drained from the lower outlet port 5 via a capture device (not shown), the capture device being a fixed head, ie the weight in the liquid formed between the upper outlet port 6 and the outlet of the capture device. Easily assures that a head equal to? The outlet of the capture device is preferably arranged above the filter 7, whereby the chamber
The inside of 3b is always filled with liquid.

The hydrostatic head is itself large enough to allow liquid to flow through the filter 7. When the emulsified fine oil droplets reach the water accumulation layer formed on the filter 7, these oil droplets are prevented from passing through the filter, are combined with other oil droplets, and are entrained by the flow of water. Stop until it is large enough to get more buoyancy. As the buoyancy of the oil drops increases, the oil collects at the top of the hollow body 2 and is then discharged via the upper outlet port 6. Known suitable control devices maintain the oil / mixture separation surface in the chamber 3a at a level lower than the upper outlet port 6 so that no mixture flows out of the upper outlet port 6. .

Therefore, surprisingly, in the device 1 of the present invention, oil droplets are prevented from penetrating into the filter 7, and the oil droplets are left on the surface of the filter 7. Thus, the improper preparation of the filter 7 or other accidents destroys the water deposits formed on the surface of the filter 7, thereby causing the passage of the untreated mixture into the filter 7. As long as is not formed, there is no need to regenerate the filter 7 or to replace the filter 7 periodically. Such a separating effect is schematically illustrated in the drawing by oil droplets (circles) collected above the water deposition layer of the filter 7. On the other hand, the water separated from the oil in the mixed liquid 11 permeates into the sedimentary layer of water, then permeates into the immersed filter 7, and finally flows out of the lower outlet port 5.

As will be appreciated from the above description, the present invention implements a physical separation system. That is, this separation system separates an untreated mixed liquid 11 consisting of a continuous aqueous phase and an oil phase dispersed therein into a water component and an oil component, and can be completely regenerated by an economical method. Separate until In this case, the aqueous phase, the phase that is actually free of oil, penetrates into the filter unit of the system, while the dispersed oil phases gradually combine with each other to form a continuous oil phase.

The driving force required to separate the water component and the oil component can be limited to the driving force obtained by the free hydrostatic head of the raw mixture 11. This hydrostatic head acting on the filter bed, when the flow rate is 0.1 to 10 cm / sec
It can be changed between 0.05 and 5mAq. Alternatively, a stream can be created by pushing the untreated mixture 11 at a desired pressure.

The apparatus and method according to the invention make it possible to filter the water from the oil by means of a system, which consists of a layer of completely immersed hydrophilic material and which is permanently formed above the support. Essentially based on the water layer,
Very high flow rate (the hydrostatic head acting on the filter
It behaves like a filter of 100m ³ / m ² h at 1 to 0.2 bar).

The action of separating water from oil takes place through a barrier formed by an aqueous layer supported by a fibril layer of hydrophilic material 8, which acts in a manner similar to a true and proper filtering action. Will be

Thus, by replacing conventional filtration cloths or panels with a layer of hydrophilic material 8 according to the present invention, any type of static or dynamic filtration device available on the market can be modified and used.

In the following, a practical example of a method for carrying out the invention is given. However, these examples do not limit the invention.

Example 1 Separation of Treated Water from Lubricating Oil A circular filter panel about 4 cm high was flanged to a hydrostatic separator according to the present invention. The separation device comprises a cylinder with a diameter of 400 mm and a cross-sectional area of 0.125 m ² .

The filter panel was protected and supported by a pair of 3 mm mesh stainless steel mesh. The hydrophilic material for the filtration panel consisting of cotton fibrils was washed and pretreated as described above. The separator was fed with a mixture of 3% oil (FIAT VS oil) in water, so that the hydrostatic head of the mixture acting on the filter bed was constant at about 1 m. The entire system was kept in circulation by mixing the filtered water with the separated oil followed by recirculation.

The test was performed continuously for 48 hours, and the following results were obtained on average.

Flow velocity through the filter: 40 m ³ / m ² h; lubricating oil contained in the treated water: 3 mg / kg or less Example 2 Separation of petroleum from seawater Hydrostatic separation of a rectangular filter panel about 5 cm in height according to the present invention The device was flanged. The separation device has a cross section of 0.
It was 5m ^2.

The filter panel was protected and supported by a pair of 3 mm mesh stainless steel mesh. The hydrophilic material is formed from a lower layer consisting of acrylic fibrils, a layer of cotton fibrils is substantially stacked on top of the lower layer to the desired height, 5 cm
I tried to be.

The separator was supplied with a mixture of 10% petroleum in seawater, so that the hydrostatic head of the mixture acting on the filter bed was constant at about 1.2 m. The entire system was kept in circulation by mixing the filtered water with the separated petroleum and then recirculating.

The test was performed continuously for a long time, and the following results were obtained on average.

Flow velocity through the filter: 32 m ³ / m ² h; amount of extractable substance CCl ₄ contained in the treated seawater: 5 m
g / kg or less Example 3 Separation of Diesel Oil from Water A square filter panel about 3 cm in height was flanged to the hydrostatic separator according to the invention. The separation device has a cross section of 20 ×
It was 20 cm.

The filter panel was protected and supported by a pair of 3 mm mesh stainless steel mesh. The hydrophilic material is formed from a lower layer consisting of acrylic fibrils, a layer of cotton fibrils is substantially stacked on top of the lower layer to the desired height, 3 cm
I tried to be.

A mixture of 5% diesel oil in water was fed to the separator so that the hydrostatic head of the mixture acting on the filter bed was constant at about 0.7 m. The entire system was kept in circulation by mixing the filtered water with the separated diesel oil and then recirculating.

The test was performed continuously for a long time, and the following results were obtained on average.

Flow rate through the filter: 48 m ³ / m ² h; treated water contained no diesel oil.

As can be seen from the above description, the present invention makes it possible to separate a mixture of an aqueous layer and an oil layer with very high selectivity and efficiency, clearly and economically, using a very simple apparatus. .

It is clear that various types of mixtures can be used as the mixture to be treated, including a large number of components, one of which is a hydrophilic component and the other at least one of which is immiscible. Even a mixed liquid can be used.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B01D 17/025 B01D 17/022

Claims (31)

(57) [Claims] An apparatus for separating two components of a mixed liquid (11) comprising a plurality of liquids that are at least partially immiscible, a component having a higher specific gravity and a component having a lower specific gravity,
The device comprises a hollow body (2), wherein the hollow body (2)
A first outlet port (5) disposed at a lower portion of the hollow body (2) for discharging a component having a higher specific gravity, and a component disposed at an upper portion of the hollow body (2) and having a lower specific gravity. A second outlet port (6) for discharging and a mixture (1) disposed in the hollow body (2) between the outlet ports (5, 6).
An inlet port (4) for feeding 1) into the hollow body (2), the device further comprising an inlet port (4).
In a device comprising a filter (7) arranged in the hollow body (2) between the first outlet port (5) and the first outlet port (5), prior to supplying the mixture (11) via the inlet port (4);
The filter (7) is supplied by supplying a component having a higher specific gravity into the hollow body (2) through the first outlet port (5).
A device which is completely and permanently immersed in the heavier component so that no air is present in the filter (7). 2. One of the plurality of liquids is an aqueous liquid, and at least one other is an oily liquid. The filter (7) is formed from a hydrophilic material (8) and immersed in clean water, Device according to claim 1, wherein a filter (7) is arranged between the inlet port (4) and the first outlet port (5). 3. The device according to claim 2, wherein the hydrophilic material (8) is formed in a granular form. 4. The method according to claim 1, wherein one dimension of each individual grain is assigned to another one.
4. The apparatus of claim 3, wherein the dimension is greater than one dimension. 5. The method according to claim 3, wherein the largest dimension among the dimensions forming the cross section of each grain is set in the range of 10 to 3,000 μm, and the length of each grain is set in the range of 2 to 50 mm. apparatus. 6. The filter according to claim 1, wherein the porosity in relation to the volume in the filter is in the range of 5 to 80%.
The apparatus according to any one of the preceding claims. 7. The device according to claim 2, wherein the hydrophilic material (8) is selected from the group consisting of vegetable fibers, natural fibers, synthetic fibers, and mixtures thereof. 8. The device according to claim 7, wherein the hydrophilic material (8) is formed from short fibers of said fibers, the individual lengths of which range from 2 to 50 mm. 9. The device according to claim 7, wherein the hydrophilic material is formed from spun waste. 10. The device according to claim 7, wherein the hydrophilic material (8) is formed from a nonwoven fabric of the fibers. 11. The filter according to claim 2, wherein both walls of the filter (7) made of the hydrophilic material (8) are formed by a net through which the one component of the mixed solution can flow. The described device. 12. A duct is provided in said inlet port (4) so as to extend into the hollow body (2), and an end of the duct located in the hollow body (2) is provided in a direction opposite to the filter (7). 3. The device as claimed in claim 2, wherein a conical diffuser (10) is provided which is directed towards the front. 13. The device according to claim 2, wherein a capture device is connected to the first outlet port (5). 14. The device according to claim 13, wherein the height of the outlet of the capture device is higher than the height of the filter. 15. The device according to claim 2, wherein the second outlet port (6) is an outlet for allowing components to be discharged by overflowing the hollow body (2). 16. The device according to claim 1, wherein the hollow body is formed from a cylinder having a circular or rectangular cross section. 17. A method for separating two components, a component having a higher specific gravity and a component having a lower specific gravity, of a liquid mixture (11) comprising a plurality of liquids that are at least partially immiscible, The method is adapted to be performed in a hollow body (2), the hollow body (2) being located at the lower part of the hollow body (2) for discharging a component having a higher specific gravity. An outlet port (5), a second outlet port (6) disposed above the hollow body (2) for discharging the component having the lower specific gravity, and a hollow body between the outlet ports (5, 6). An inlet port (4) arranged in (2) for supplying the mixed liquid (11) into the hollow body (2), between the inlet port (4) and the first outlet port (5); Mixing via the inlet port (4) in a method wherein the filter (7) is arranged in the hollow body (2) of the Prior to supplying the liquid (11), a first outlet port (5) is provided in the hollow body (2).
The filter (7) is completely and permanently immersed in the heavier component by feeding the heavier component through the filter so that no air is present in the filter (7), The mixed liquid (11) is supplied into the body (2), and the mixed liquid (11) is filtered by the hydrostatic head using the filter (7).
And recovering the component having the higher specific gravity from the first outlet port (5) and the component having the lower specific gravity from the second outlet port (6), respectively. 18. One of the plurality of liquids is an aqueous liquid, and at least one other is an oily liquid. The filter (7) is formed of a hydrophilic material (8) and immersed in clean water. 18. The method according to claim 17, wherein the filter (7) is located between the inlet port (4) and the outlet port (5) for discharging the separated aqueous components. 19. The method according to claim 18, wherein the hydrophilic material (8) is formed in a granular form. 20. The method of claim 19, wherein one dimension of each individual grain is defined to be greater than the other two dimensions. 21. The largest dimension among the dimensions forming the cross section of each grain is set in the range of 10 to 3,000 μm, and the length of each grain is 2 to 50 mm.
20. The method according to claim 19, wherein the method is defined as: 22. The method according to claim 17, wherein the porosity with respect to the volume in the filter is in the range from 5 to 80%. 23. The method according to claim 18, wherein the hydrophilic material (8) is selected from the group consisting of vegetable fibers, natural fibers, synthetic fibers, and mixtures thereof. Method. 24. The method according to claim 23, wherein the hydrophilic material (8) is formed from short fibers of which the individual length is in the range of 2 to 50 mm. 25. The method according to claim 23, wherein the hydrophilic material (8) is formed from spun waste. 26. The method according to claim 23, wherein the hydrophilic material (8) is formed from a nonwoven fabric of the fibers. 27. The method according to claim 17, wherein the hydrostatic head is set in the range of 0.05 to 5 mAq. 28. The height of the mixture (11) is adjusted by the filter (7).
28.The hydrostatic head is controlled by controlling the head to be higher than a predetermined height.
The method described in. 29. The method according to claim 27, wherein the hydrostatic head is controlled by a pump device. 30. The method according to claim 17, wherein the flow of the mixture (11) in the filter (7) is laminar. 31. The flow rate of the mixture (11) in the filter (7) is set in the range of 0.001 to 0.1 m / s.
19. The method according to claim 7 or claim 18.