CN103980934A - Deep dehydrating method and device for oil product - Google Patents

Abstract

The invention relates to a method and device for deep dehydration of oil products. The oil containing a small amount of water first passes through the rectifier to make the fluid evenly distributed, and then passes through one or several sections of oleophilic and hydrophobic and oleophilic and oleophobic fiber braided in an X shape to capture, coalesce and grow traces of water droplets. Demulsification and separation of emulsion in water form, followed by the rapid coalescence, growth and separation of water droplets through corrugated enhanced sedimentation separation, and finally through a section of oleophilic and hydrophobic and oleophilic and oleophobic fiber braided in an Ω-shaped braided layer for oil neutralization Complementary collection and separation of extremely small water droplets to achieve deep dehydration of oil products. The invention also provides a set of devices for realizing the method, which includes several parts such as a housing, a feed pipe, a rectifier, a fiber coalescence layer, a corrugated reinforced separation layer, and a liquid level gauge. This technology has high separation efficiency, low energy consumption and long continuous operation period, and can be widely used in the deep dehydration process of oil products containing trace amounts of water.

Description

A method and device for deep dehydration of oil products

technical field

The invention belongs to the field of petrochemical oil dehydration, and in particular relates to a method and device for deep dehydration of oil.

Background technique

Water content in oil has a major impact on the safe use of petrochemical production equipment and subsequent refined oil in engines. For example, water content in crude oil will increase the transportation volume, and more importantly, it will bring difficulties to crude oil processing, increasing atmospheric and vacuum distillation. The energy consumption of the device. Because the relative molecular energy of water is much smaller than that of oil, the volume increases sharply after gasification, which increases the pressure drop of the system and the power consumption increases accordingly. Therefore, if the water content in the oil is high, the operation of the device will fluctuate, causing Punch tower. Moreover, the inorganic salts (Call2, MgCl2) brought in by water will also aggravate the corrosion of the device. Water in light fuel oil will increase the freezing point and crystallization point, resulting in poor low-temperature water mobility of the oil, causing ice particles to be analyzed at low temperatures and blocking the filter and oil circuit, especially in aviation kerosene and diesel oil. The water contained in the oil will cause interruption of oil supply and lead to serious accidents. The water in the lubricating oil will destroy the lubricating film, make the lubrication cannot be carried out normally, and increase the wear of the parts. The inorganic salt brought by the water will also increase the corrosiveness of the lubricating oil and aggravate the corrosion of the machine parts. When using lubricating oil containing water to work in a higher temperature environment, the lubricating film will be destroyed due to the vaporization of water. Exceeding the water content in the reforming raw oil will poison the catalyst, because too much water in the oil occupies the acidic center of the catalyst, destroying the balance of the metal center of the acidic center, reducing the activity of the catalyst or even deactivating it, and affecting the service life of the catalyst. When the water in petroleum products evaporates, it absorbs heat, which will reduce the calorific value; the water in light oil will deteriorate the combustion process, and can bring dissolved salt into the cylinder, forming carbon deposits and increasing the wear of the cylinder; At low temperature, the water in the fuel will freeze, block the fuel conduit and filter, and hinder the fuel supply of the generator fuel system; the water in the petroleum product will accelerate the oxidation of the oil; the water in the lubricating oil will not only It will cause corrosion of engine parts, and when water contacts metal parts above 100°C, it will turn into water vapor and destroy the lubricating oil film. Light oil products have low density, low viscosity, and easy separation of oil and water. On the contrary, heavy oil products are not easy to separate. The water content of crude oil entering the atmospheric and vacuum distillation unit is required to be no more than 0.2-0.5%; the specifications and standards of refined oil require that gasoline and kerosene contain no water, and the water content of light diesel oil should not exceed traces (the traces are generally considered as 300mg/L); The content is not more than 0.5-1.5%; various lubricating oils and fuel oils have corresponding control indicators. Therefore, deep dehydration of oil has an important impact on petrochemical production and subsequent efficient use of oil.

At present, the main technologies for oil dehydration by physical means include gravity sedimentation, cyclone separation, coalescence filtration and other methods, as well as dehydration by other means such as salt adsorption, flash evaporation, and electric field separation. For gravity sedimentation, it can mainly remove clear water in oil products, that is, free water droplets with a particle size greater than 100 μm, and can not effectively separate and remove dispersed water droplets below 100 μm; cyclone separation technology is suitable for rapid removal of large amounts of water. Water droplets below 15 μm and emulsified water droplets cannot be effectively separated, because the potential energy needs to be converted into rotational kinetic energy for separation, and the energy consumption is relatively high; coalescing filtration is separated by permeability, and the scope of application is narrow, and there is a short service life in the factory application process However, the use of salt adsorption, electric field separation, and flash separation is relatively energy-consuming and complex in operation, and is only suitable for specific treatment media.

The patent ZL01823742.8 oil dehydrator discloses a method of dehydrating oil by using a membrane, but there are problems of high cost of use and easy pollution and damage; the patent application number 200810042145.2 discloses a method and device for dehydrating diesel oil. The cyclone method is used for separation. Due to the technical characteristics of cyclone separation, it is only suitable for the separation of free water droplets above 15 μm, and the operating pressure drop is large, which cannot achieve deep dehydration of oil products with high efficiency and low consumption; patent ZL201010145423.4 A heavy oil and coal tar dehydrator is disclosed, which uses drum evaporation for dehydration, which has relatively high energy consumption and complicated operation, and is only suitable for the oil dehydration process of specific media. ZL200910065725.8 discloses a dehydration method using electric field and devices, patent 201010261697.X discloses a method and device for dehydration using ultrasonic technology, and patent application number 201310352748.3 discloses a method for dehydrating heavy dirty oil using the method of filtration-swirl-coalescence-swirl , the above patented technologies are only suitable for specific occasions, and all have the problems of high energy consumption and narrow application range, and cannot meet the requirements of deep dehydration of oil products.

Therefore, there is an urgent need in this field to develop a deep oil dehydration technology with low cost, simple operation, low energy consumption and high efficiency.

Contents of the invention

In order to solve the above-mentioned deficiencies in the prior art, the present invention provides a method and device for deep dehydration of oil products, and the specific technical scheme is as follows:

A method for deep dehydration of oil products, comprising the steps of:

(1) First, the oil product containing a small amount of water is rectified by a fluid rectifier, so that the fluid is evenly distributed in the radial section of the fluid flow; the concentration of the trace water in the oil product is not more than 1000mg/L, and the concentration of the trace water The particle size of water droplets is 0.1-30μm, and the operating temperature is 5-99℃;

(2) The rectified water-containing oil product evenly enters the X-shaped braided layer formed by the interweaving of hydrophilic-oleophobic fibers and lipophilic-hydrophobic fibers, and captures and coalesces trace water droplets in the X-shaped braided layer Demulsification and separation of large and small water-in-oil emulsions. After the process, the particle size of water droplets grows to 10-50 μm;

(3) The oil product coalesced and separated in step (2) enters the corrugated strengthening separation layer for rapid growth and separation of water droplets, and after this process, the water content of the oil product is reduced to within 200 mg/L;

(4) the oil product after the separation of step (3) enters the Ω-shaped braided layer of the hydrophilic-oleophobic fiber and the lipophilic-hydrophobic fiber before the outlet, and in the described Ω-shaped braided layer, unseparated dispersed water droplets and The emulsified water droplets are subjected to deep supplementary separation, and after this process, the water content in the oil is reduced to less than 20mg/L.

The fluid rectifier is a thick plate with holes evenly distributed, the holes are round holes or square holes, the opening ratio is greater than or equal to 60%, and the opening ratio is the percentage of the opening area to the plate area.

The included angle between the hydrophilic and oleophobic fibers in the X-shaped braided layer of step (2) and the horizontal line is 25° to 60° (clockwise), and the X-shaped fiber braided layer is one or more pieces filled with the entire fluid cross section of the flow.

After long-term research by the inventor, it has been found that when the angle between the hydrophilic and oleophobic fibers and the horizontal line (oleophilic and hydrophobic fibers) is between 25 degrees and 45 degrees, there is a high separation efficiency for emulsified water droplets, because the hydrophilic and oleophobic fibers and The angle between the horizontal lipophilic and hydrophobic fibers is small. When the emulsified water droplet (water-in-oil) moves to the node of the two fibers, as shown in Figure 1, the water droplet Under the drag force of hydrophilic and oleophobic fibers, when the angle is small, the force process of water droplets is longer when the horizontal movement distance is equal, and it is easier to be separated. On the contrary, if the angle is large, the force process of water droplets is short and difficult to separate. ; and when the angle between the hydrophilic and oleophobic fibers and the horizontal line is between 45 degrees and 60 degrees, it has a better effect on the rapid separation of dispersed water droplets. Because of the large horizontal angle, the water droplets can move along the hydrophilic surface more quickly when moving horizontally. Sexual fibers move downward and are rapidly separated.

The spacing a between two adjacent oleophilic and hydrophobic fibers in the X-shaped braided layer is 1 to 3 times the spacing b between two adjacent hydrophilic and oleophobic fibers.

The corrugated strengthening separation layer described in step (3) adopts a hydrophilic material, wherein the distance between the corrugated plates is 5-25 mm, and there are round holes with a diameter of 5-10 mm at the wave trough, and the distance between the round holes is 50~300mm.

In the Ω-shaped braided layer of step (4), the ratio of the number of hydrophilic-oleophobic fibers to lipophilic-hydrophobic fibers is 3:2 to 7:1, and the area of the Ω-shaped braided layer is 30% of the fluid flow cross-sectional area. ~80% and located in the upper cross-section where the fluid flows; in addition, the Ω-shaped braided layer is formed by pre-arranging the hydrophilic-oleophobic fibers and the lipophilic-hydrophobic fibers in an Ω-shape and interlacing. In this process, the Ω-shaped weaving is more focused on the adsorption of hydrophilic and oleophobic fibers. The Ω-shaped weaving has many contact points and is made of hydrophilic fibers. It has a horizontal corrugated shape along the oil flow direction, and has a diversion and traction for particularly small water droplets. And the role of adsorption, while moving to the concave position, it can also play the role of water droplet accumulation and growth, and then capture and separate the smaller water droplets in the exported oil to achieve the effect of deep dehydration, as shown in Figure 2.

The lipophilic and hydrophobic fibers are selected from modified polypropylene, Teflon, and nylon, and the hydrophilic and oleophobic fibers are selected from metals and ceramics.

The pressure loss of oil dehydration in the whole process is 0.01-0.05MPa.

A device for realizing any of the above methods, the device includes a housing, an oil inlet, a fluid rectifier, a fiber coalescing separation layer, a corrugated reinforced separation layer, a fiber coalescence replenishment layer, a water bag, and an outlet for purifying the oil phase;

Wherein, the inlet of the oil product is at one end of the upper part of the housing, and the outlet of the purified oil phase is at the other end of the upper part of the housing; the water bag is at the lower part of the housing, and the water bag is connected with the The outlet of the purified oil phase is relatively or slightly deviated. The water bag has a liquid level gauge, and the bottom of the water bag is provided with a water phase outlet; a fluid rectifier, a fiber coalescence separation layer, a corrugated reinforced separation layer, a fiber aggregation The knot-complementary layer is located inside the housing and arranged sequentially without connection, wherein the fluid rectifier is close to the oil inlet, and the area of the fiber coalescence-complementary layer is 30-30% of the cross-sectional area of the fluid flow. 80% and in the upper section of fluid flow.

The shell is a horizontal circular tank, or a horizontal rectangular parallelepiped tank.

The fiber coalescing separation layer is an X-shaped braided layer formed by weaving lipophilic and hydrophobic fibers and hydrophilic and oleophobic fibers, wherein the angle between the hydrophilic and oleophobic fibers and the horizontal line is 25 degrees to 60 degrees; and, two adjacent The spacing a of the root lipophilic and hydrophobic fibers is 1 to 3 times the spacing b of two adjacent hydrophilic and oleophobic fibers;

The fiber coalescing supplementary layer is an Ω-shaped braided layer formed by weaving hydrophilic-oleophobic fibers and lipophilic-hydrophobic fibers, wherein the number ratio of hydrophilic-oleophobic fibers to lipophilic-hydrophobic fibers is 3:2～7: 1. Since the water content in the oil is small, the higher the proportion of hydrophilic fibers, the greater the probability of capturing water droplets, and because the lower content of water droplets adheres to the oil droplets in the form of tiny particles, the proportion is controlled at 1 to 3 The effect is the best when it is doubled, because part of it needs to be demulsified and separated by the force of hydrophilic-oleophobic and lipophilic-hydrophobic fiber nodes, but the efficiency is not significantly improved when it exceeds 3 times, and the cost is lower if the proportion of hydrophilic fibers is increased. Big and meaningless.

The corrugated reinforced separation layer is made of hydrophilic material, wherein the distance between the corrugated plates is 5-25 mm, and round holes with a diameter of 5-10 mm are opened at the troughs, and the distance between the round holes is 50-300 mm. In this part of the water droplets have been coalesced and grown in the upper level. During the corrugated flow process, the water droplets accumulate in the recesses of the corrugated plate due to their high density, and quickly grow into larger water droplets and sink and separate.

The beneficial effect of the present invention is that the fluid is evenly distributed, and the hydrophilic-oleophobic and lipophilic-hydrophobic are braided in different combinations to play the role of demulsification, coalescence, and rapid diversion and sinking of water droplets. Combination of targeted separation forms based on specific characteristics, high efficiency and low consumption, suitable for oil dehydration in different processes.

Description of drawings

Figure 1 is a schematic diagram of the principle of demulsification and separation;

Fig. 2 is the depth water removal schematic diagram of Ω-shaped braided layer;

Fig. 3 is a schematic structural view of an X-shaped braided layer;

Figure 4 is a schematic diagram of the separation of water droplets on the X-shaped braided layer;

Fig. 5 is the schematic diagram of the weaving process that hydrophilic-oleophobic fibers and lipophilic-hydrophobic fibers form an Ω-shaped braided layer;

Fig. 6 is a schematic structural diagram of a device suitable for deep dehydration of oil containing a small amount of water.

Symbol Description:

1 shell; 2 oil inlet; 3 fluid rectifier; 4, X-shaped braiding layer;

5 corrugated reinforced separation layer; 6 Ω-shaped braided layer; 7 purified oil phase outlet;

8 liquid level gauge; 9 water phase outlet; 10 water bag.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example

Two sets of diesel hydrogenation units in a petrochemical company adopted the method and device for deep dehydration of oil products of the present invention to dehydrate the diesel oil from the fractionation tower of the diesel hydrogenation unit, and the dehydrated diesel oil was sent to the finished oil tank.

The structural schematic diagram of the above-mentioned device is shown in Figure 6, including a housing 1, an oil inlet 2, a fluid rectifier 3, an X-shaped braided layer 4 (fiber coalescence separation layer), a corrugated reinforced separation layer 5, and an Ω-shaped braided layer 6 ( fiber coalescing replenishment layer), water bag 10 and purified oil phase outlet 7;

Wherein, the oil inlet 2 is at one end of the upper part of the housing 1, and the purified oil phase outlet 7 is at the other end of the upper part of the housing 1; the water bag 10 is at the bottom of the housing 1, and the water bag 10 is opposite to or slightly Relatively arranged with deviation, the water bag 10 has a liquid level gauge 8, and the bottom of the water bag 10 is provided with a water phase outlet 9; the fluid rectifier 3, the X-shaped braided layer 4, the corrugated reinforced separation layer 5, and the Ω-shaped braided layer 6 are located in the shell The interior of the body 1 is arranged sequentially without connection, wherein the fluid rectifier 3 is close to the oil inlet 2, and the area of the Ω-shaped braided layer 6 is 30-80% of the cross-sectional area of the fluid flow and is in the upper section of the fluid flow.

The housing 1 in Fig. 6 of the present embodiment is a horizontal circular tank, and a horizontal rectangular parallelepiped tank can also be selected.

The schematic diagram of the structure of the X-shaped braided layer 4 is shown in Figure 3, wherein the angle between the hydrophilic and oleophobic fibers and the horizontal line can be 25 to 60 degrees; the distance a between two adjacent oleophilic and hydrophobic fibers is The spacing b of hydrophilic and oleophobic fibers is 1 to 3 times; FIG. 1 is a schematic diagram of the principle of demulsification and separation of fluid on the X-shaped braided layer 4 , and FIG. 4 is a schematic diagram of the separation of water droplets on the X-shaped braided layer 4 .

Fig. 2 is a schematic diagram of depth water removal of Ω-shaped braided layer, and Fig. 5 is a schematic diagram of weaving process of hydrophilic-oleophobic fibers and lipophilic-hydrophobic fibers to form Ω-shaped braided layer, wherein the ratio of hydrophilic-oleophobic fibers to lipophilic-hydrophobic fibers is 3:2～7:1.

Use the above-mentioned device to carry out deep degreasing of wastewater containing low-concentration dirty oil. The specific operation process and effect are described as follows:

Operating conditions:

project Diesel Hydrogenated Diesel Hydrogenated heavy diesel oil medium Diesel (trace water) Diesel (trace water) Flow, t/h 40 50 Inlet pressure, MPa 1.3 0.5 Operating temperature, °C 50 50 Density, kg/m3 810 855 Inlet free water, ppm 600 500 Export free water requirement, ppm 80 80 residual, v% 4.2 1.7 Colloid, mg/100ml 100 / Viscosity, mm2/s 3.635 6.128

Requirement index: The oil content in the sewage after degreasing is not more than 80mg/L.

Scheme selection: In this scheme, the water content of diesel oil is relatively low, and it has undergone sedimentation and separation at the initial stage. Therefore, most of the water droplets are dispersed in the diesel oil in the form of tiny particles. Because the export requires that the oil content should be stable and not greater than 80mg/L, fluid rectifiers, X The combined method of separation of fiber braided layer, corrugated reinforcement separation, and deep separation of Ω-shaped fiber braided layer is processed.

(1) Diesel oil in diesel hydrogenation unit: Considering the low density of diesel oil and the small amount of emulsified water in diesel oil in hydrogenation unit, the X-shaped fiber braided layer adopts a one-stage type, and the fiber spacing ratio of the X-shaped fiber braided layer is a:b = 2.5, (As shown in Figure 3, the spacing between two adjacent lipophilic and hydrophobic fibers is a, and the spacing between two adjacent hydrophilic and hydrophobic fibers is b; is the angle between the hydrophilic and oleophobic fibers and the horizontal line), this angle is suitable for the efficient and rapid replenishment and coalescence of small water droplets and rapid diversion separation, and has a partial demulsification effect on emulsified water droplets; the corrugated plate in the corrugated strengthening separation section is made of 316L material , The corrugated plate spacing is 15mm. Considering the low water content in diesel oil required for export, the ratio of hydrophilic and oleophobic fibers to oleophilic and hydrophobic fibers in the Ω-shaped fiber braid layer is 2.5:1, which is suitable for demulsification and separation of water droplets that have not been demulsified and separated and in oil products. Complementary separation of tiny water droplets.

(2) Hydrogenation and modification of heavy diesel oil: Considering the high density of diesel oil, the X-shaped fiber braided layer adopts a two-stage type, and the fiber spacing ratio of the first X-shaped fiber braided layer is a:b=2, (a, b, The definition is as above), this angle is suitable for the efficient and rapid replenishment and coalescence of small water droplets and the demulsification of partially emulsified water droplets. In addition, it can take into account the small density difference between diesel oil and water, and the small angle is conducive to the diversion and separation of water droplets; the second The fiber spacing ratio of section X-shaped fiber braided layer is a:b=1.5, °(a, b, The definition of is as above), suitable for the rapid diversion and sinking separation of small water droplets after the coalescence of the first stage. The corrugated plate of the corrugated strengthening separation section is made of 316L material, and the distance between the corrugated plates is 18mm. Considering the low water content in diesel oil required for export, the ratio of hydrophilic-oleophobic fibers to lipophilic-hydrophobic fibers in the Ω-shaped fiber braid layer is 2:1, which is suitable for the complementary collection and separation of trace water droplets in oil products.

Result analysis: After diesel dehydration in the diesel hydrogenation unit, the water content in the purified oil is 30-50 mg/L; after the dehydration of hydrogenated heavy diesel oil, the water content in the purified oil is 45-65 mg/L, which is stably less than 80 mg/L The separation requirements of L, the inlet and outlet pressure drop is 0.01MPa, the energy consumption is low, and the design operation conditions are met.

In summary, the above are only preferred embodiments of the present invention, and are not intended to limit the implementation scope of the present invention. And all equivalent changes and modifications made according to the content of the patent scope of the present invention should be within the technical scope of the present invention.

Claims (10)

1. a method for oil product deep dehydration, is characterized in that, comprises the steps:

(1) first, carry out rectification containing the oil product of minor amount of water by fluid rectifier, make fluid realize and being uniformly distributed at the mobile radial section of fluid; In described oil product, the concentration of minor amount of water is not more than 1000mg/L, and the drop particle diameter of described minor amount of water is 0.1～30 μ m, and service temperature is 5～99 DEG C;

(2) the minor amount of water oil product that contains after rectification evenly enters the X-shaped braid of hydrophilic oleophobic property fiber and lipophilic-hydrophobic property fiber weaving, in described X-shaped braid, carry out the catching of micro-water droplet, coalescent growing up and breakdown of emulsion, the separation of micro-water in oil form emulsion, after this end of processing, drop particle diameter is grown up to 10～50 μ m;

(3) oil product after step (2) coarse separation enters ripple strengthening separating layer and carries out growing up fast of water droplet and separate, and after this process, moisture of oil is reduced in 200mg/L;

(4) oil product after step (3) separates advances into the Ω shape braid of hydrophilic oleophobic fiber and oleophilic drainage fiber in outlet, in described Ω shape braid to oil product in unsegregated dispersion water droplet carry out degree of depth supplementary set with emulsification water droplet and separate, after this process, in oil product, water content is reduced in 20mg/L.

2. the method for claim 1, is characterized in that, described fluid rectifier is the uniform perforate slab of a porous, and described hole is circular hole or square opening, and percentage of open area is more than or equal to 60%.

3. the method for claim 1, it is characterized in that, in the described X-shaped braid of step (2), hydrophilic oleophobic property fiber and horizontal angle are 25 degree to 60 degree, and described X-shaped fiber braiding layer is 1 or is lumpily full of the mobile cross section of whole fluid.

4. the method for claim 1, is characterized in that, in described X-shaped braid, the spacing a of adjacent two lipophilic-hydrophobic property fibers is 1～3 times of spacing b of adjacent two hydrophilic oleophobic property fibers.

5. the method for claim 1, it is characterized in that, what the strengthening of ripple described in step (3) separating layer adopted is hydrophilic material, and wherein the spacing of waved plate is 5～25mm, trough place has the circular hole of diameter 5～10mm, and the spacing between described circular hole is 50～300mm.

6. the method for claim 1, it is characterized in that, in the described Ω shape braid of step (4), the quantitative proportion of hydrophilic oleophobic property fiber and lipophilic-hydrophobic property fiber is 3:2～7:1, the area of described Ω shape braid be fluid cross-sectional flow area 30～80% and be positioned at the mobile cross section, top of fluid; Described Ω shape braid is that after in advance hydrophilic oleophobic property fiber and lipophilic-hydrophobic property fiber being arranged as to Ω shape separately, weaving forms.

7. the method for claim 1, is characterized in that, in whole process, the pressure-losses of oil dehydrating is 0.005～0.05MPa.

8. realize the device of the arbitrary described method of claim 1～7 for one kind, it is characterized in that, described device comprises housing, oil product entrance, fluid rectifier, fiber coarse separation layer, ripple strengthening separating layer, the coalescent supplementary set layer of fiber, water bag and purifies oil phase outlet;

Wherein, described oil product entrance is in one end, top of described housing, and described purification oil phase exports at the top of the described housing the other end; Described water wraps in the bottom of described housing, and this water bag exports relative or is slightly oppositely arranged to deviation with described purification oil phase, and described water bag has liquid level meter, and the bottom of described water bag is provided with water outlet; Fluid rectifier, fiber coarse separation layer, ripple strengthening separating layer, the coalescent supplementary set layer of fiber are positioned at the inside of described housing and conjointly do not arrange mutually successively, wherein, described fluid rectifier is near described oil product entrance, the area of the coalescent supplementary set layer of described fiber be fluid cross-sectional flow area 30～80% and in the mobile cross section, top of fluid.

9. device as claimed in claim 8, is characterized in that, described housing is horizontal circular tank, or horizontal rectangular parallelepiped tank.

10. device as claimed in claim 8, is characterized in that, described fiber coarse separation layer is that oleophilic drainage fiber and hydrophilic oleophobic fiber weave the X-shaped braid forming, and wherein hydrophilic oleophobic property fiber and horizontal angle are 25 degree to 60 degree; And the spacing a of adjacent two lipophilic-hydrophobic property fibers is 1～3 times of spacing b of adjacent two hydrophilic oleophobic property fibers;

The coalescent supplementary set layer of described fiber is that hydrophilic oleophobic property fiber and lipophilic-hydrophobic property fiber weave the Ω shape braid forming, and wherein the quantitative proportion of hydrophilic oleophobic property fiber and lipophilic-hydrophobic property fiber is 3:2～7:1.