CN116236816A - A compound sieve plate extraction tower and its application in low interfacial tension extraction system - Google Patents

Abstract

The invention discloses a composite sieve plate extraction tower and application thereof in a low interfacial tension extraction system, wherein the composite sieve plate extraction tower consists of a stirring section and a clarifying section, the upper end of the stirring section is provided with a composite sieve plate A, the lower end of the stirring section is provided with a composite sieve plate B, two sides of the composite sieve plate A and the composite sieve plate B are respectively made of two materials with different hydrophilic and hydrophobic properties, one side of the composite sieve plate A and the composite sieve plate B is made of hydrophilic materials, the other side of the composite sieve plate A and the composite sieve plate B are made of hydrophobic materials, when an oil phase in the extraction tower is a disperse phase, the hydrophilic materials face the clarifying section, the hydrophobic materials face the stirring section, and when an aqueous phase in the extraction tower is a disperse phase, the hydrophilic materials face the stirring section, and the hydrophobic materials face the clarifying section. The composite sieve plate extraction tower can realize the circulation of dispersing-coalescence-redispersing of dispersed phase liquid drops when treating a low interfacial tension extraction system, is not easy to emulsify, has wide operating range and large equipment flux, remarkably improves the extraction efficiency, and solves the problems of easy emulsification, difficult coalescence, small flux and low efficiency of the low interfacial tension extraction system.

Description

A compound sieve plate extraction tower and its application in low interfacial tension extraction system

technical field

The invention belongs to the field of extraction and separation, and relates to a composite sieve plate extraction tower and its application in a low interfacial tension extraction system.

Background technique

In the chemical production process, many extraction processes involve low interfacial tension systems, such as the extraction and separation of high-carbon alcohol hydrocarbon mixtures, lubricating oil refining extraction systems, sulfolane aromatics extraction, n-butyl acetate extraction of erythromycin, copper ore solvent extraction, etc. . The low interfacial tension system is easy to emulsify during the extraction process, so the flux is low, the extraction efficiency is poor, and it will also have a great impact on product quality and yield. New extraction equipment is urgently needed to solve the problems of easy emulsification and low flux, so as to improve extraction. efficiency and product quality.

Zhu Shenlin et al. (Petroleum Refining, 1993, 24 (4): 8-13) studied the mass transfer characteristics of the low interfacial tension system in the sieve plate extraction tower, using low interfacial tension n-butanol-succinic acid- In the water system, the average droplet diameter and plate efficiency were studied in the large sieve plate extraction column, which provided a reference for the optimization of the sieve plate column in the extraction and separation of sulfolane aromatics. At the same time, an example of the industrial application of the large sieve plate tower was given, and the daily processing capacity of the original industrial extraction tower for extracting heavy aromatics in diesel oil was increased by 15%, which improved the economic benefit. However, the large sieve plate extraction tower has serious axial backmixing, especially for systems with small density differences, which is not conducive to the improvement of extraction efficiency.

Cui Jianhua et al. (CN205699575U) disclose a novel composite extraction sieve plate, the sieve plate body has two opposite surfaces, which are respectively coated with a hydrophilic material layer and a hydrophobic material layer. The placement direction of the sieve plate surface material is determined by the characteristics of the dispersed phase, so that the dispersed phase can contact the compatible surface for the first time, thereby promoting coalescence and improving extraction efficiency. The composite sieve plate has a certain effect on alleviating the emulsification phenomenon of the low interfacial tension extraction system, but due to the coalescence of the dispersed phase on the compatible surface, the mass transfer specific surface area decreases, and it cannot solve the problem of low throughput of the equipment. problem.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, to provide a composite sieve plate extraction tower and its application method in the low interfacial tension extraction system.

The invention provides a composite sieve plate extraction tower, which is composed of stirring sections and clarification sections alternately along the tower height direction, the upper end of the stirring section is provided with a composite sieve plate A, the lower end is provided with a composite sieve plate B, and the composite sieve plates A and B are The two sides of the composite sieve plate are two kinds of materials with different hydrophilic and hydrophobic properties, one side is a hydrophilic material, and the other side is a hydrophobic material. When the oil phase in the extraction tower is a dispersed phase, the hydrophilic material faces of the composite sieve plates A and B face the clarification section , the hydrophobic material faces the stirring section, and when the water phase in the extraction tower is the dispersed phase, the hydrophilic materials of the composite sieve plates A and B face the stirring section, and the hydrophobic material faces the clarification section.

According to a preferred embodiment of the present invention, the hydrophilic material is a metal material such as stainless steel, aluminum or titanium, and its thickness is 0.5-10 mm.

According to a preferred embodiment of the present invention, the hydrophobic material is polytetrafluoroethylene, polyethylene or polypropylene, and its thickness is 0.5-10 mm.

According to a preferred embodiment of the present invention, the composite sieve plates A and B are provided with openings on the side facing the stirring section, the opening method is uniform opening, the hole diameter is 1.0-4.0mm, and the opening rate is 5-30%.

According to a preferred embodiment of the present invention, the sides of the composite sieve plates A and B facing the clarification section are perforated or grooved at positions corresponding to the openings on the surface facing the stirring section, the diameter of the holes is 4.0-10.0mm, and the width of the groove Not less than the diameter of the hole on the surface facing the stirring section and not more than 10.0mm.

According to a preferred embodiment of the present invention, the sides of the composite sieve plates A and B facing the clarification section adopt a combination of grooves and holes at the positions corresponding to the openings on the surface facing the stirring section, and the hole diameter is 4.0-10.0 mm, the width of the groove is not less than the diameter of the hole on the surface facing the stirring section and is not more than 10.0mm.

According to an optional embodiment of the present invention, the side of the composite sieve plate A facing the clarification section adopts the method of external grooves and internal holes, and the side of the composite sieve plate B facing the clarification section adopts the method of internal grooves and external holes.

According to an optional embodiment of the present invention, the side of the composite sieve plate A facing the clarification section adopts the method of internal grooves and external openings, and the side of the composite sieve plate B facing the clarification section adopts the method of external grooves and internal openings.

The present invention also provides an application of the above-mentioned compound sieve plate extraction tower in the extraction of a low interfacial tension extraction system. The low interfacial tension extraction system refers to a system with an interfacial tension less than 3mN/m. Typical but not limited, such as lubricating oil refining extraction system, sulfolane aromatics extraction system, n-butanol-succinic acid-water system, cyclohexane-isopropanol-water system, and extraction and separation of high-carbon alcohol hydrocarbon mixtures Heptanol-undecane-ethanol-water, octanol-dodecane-ethanol-water, nonanol-tridecane-ethanol-water, decyl alcohol-tetradecane-ethanol-water and other systems.

The advantage of the present invention is that the surface of the sieve plate material with good wettability to the dispersed phase faces the stirring section, which is beneficial to the adsorption and coalescence of the dispersed phase droplets on the surface of the sieve plate in the stirring section, and at the same time, the adsorption and coalescence When the merged droplets leave the sieve plate and enter the clarification section, they are affected by the poor wettability of the sieve plate material facing the clarification section and its larger openings or wider slots, so it can not only leave smoothly, but also disperse into small liquids again. Therefore, the composite sieve plate extraction tower can realize the cycle of "dispersion-coalescence-redispersion" of dispersed phase liquid droplets when dealing with low interfacial tension extraction systems. It is not easy to emulsify, has a wide operating range, large equipment throughput, and remarkable extraction efficiency Improvement, solves the problems of easy emulsification, difficult aggregation, small flux and low efficiency of low interfacial tension extraction system.

Description of drawings

Figure 1 is a schematic diagram of the structure of a composite sieve plate extraction tower.

Figure 2 is a schematic diagram of composite sieve plate material.

Figure 3 and Figure 4 are schematic diagrams of the slotting method.

Fig. 5 is a schematic diagram of an external groove and an internal opening.

Fig. 6 is a schematic diagram of internal slotting and external opening.

Detailed ways

As shown in Figures 1 and 2, the present invention provides a composite sieve plate extraction tower, which is composed of stirring sections and clarification sections alternately along the tower height direction, the upper end of the stirring section is provided with a composite sieve plate A, and the lower end is provided with a composite sieve plate Plate B, the two sides of composite sieve plates A and B are respectively two kinds of materials with different hydrophilic and hydrophobic properties, one side is hydrophilic material, and the other side is hydrophobic material. When the oil phase in the extraction tower is the dispersed phase, the hydrophilic materials of the composite sieve plates A and B face the clarification section, and the hydrophobic materials face the stirring section; when the water phase in the extraction tower is the dispersed phase, the composite sieve plates A and B face The hydrophilic material side faces the stirring section, and the hydrophobic material side faces the clarification section.

The stirring section in the composite sieve plate extraction tower is a section provided with stirring devices (such as stirring paddles), and the clarification section is a section not provided with stirring paddles. In the present invention, the stirring section and the clarification section are divided by a composite sieve plate, and the composite sieve plate is provided with openings, slots or slot composite structures connecting the upper and lower sections, so that the liquid can circulate. The stirring paddles in each stirring section can be driven by the same belt-driven stirring shaft to rotate synchronously, and other stirring driving methods can also be used. The height of the stirring section and the clarifying section can be selected according to the characteristics of the system, generally not exceeding the diameter of the extraction tower, and the number of the stirring section and the clarifying section is selected according to the characteristics of the system and the extraction effect to be achieved.

Among them, the hydrophilic material can be selected as metal materials such as stainless steel, aluminum or titanium, and its thickness is 0.5-10 mm. The hydrophobic material can be polytetrafluoroethylene, polyethylene or polypropylene, and its thickness is 0.5-10mm. The composite sieve plates A and B of the present invention are provided with openings on one side facing the stirring section, the opening method is uniform opening, the diameter of the holes is 1.0-4.0 mm, and the opening rate is 5-30%.

When the aqueous phase in the extraction tower is a dispersed phase, in an embodiment of the present invention, the side of the composite sieve plates A and B facing the stirring section is a hydrophilic material surface, and the surface is uniformly perforated according to the aforementioned opening requirements, On the surface of the hydrophobic material, holes or slots are opened at the positions corresponding to the openings on the surface of the hydrophilic material. The diameter of the hole is 4.0-10.0mm. The groove method is shown in Figure 3 or Figure 4. Among them, Figure 3 is an arc-shaped groove, and Figure 4 is a linear groove.

Further, when the surface of the above-mentioned hydrophilic material is evenly opened, the surface of the hydrophobic material adopts a combination of slotting and opening at the position corresponding to the opening of the hydrophilic material surface, the diameter of the hole is 4.0-10.0mm, and the width of the groove is not less than The diameter of the holes on the surface of the hydrophilic material should not be greater than 10.0 mm, and the slotting and opening methods are shown in Figure 5 or Figure 6.

Further, when the above-mentioned hydrophobic material surface adopts the combination of slotting and opening, an optional implementation mode is: the hydrophobic material surface of the composite sieve plate A adopts the method of external grooves and internal openings, as shown in Figure 5 As shown, the hydrophobic material surface of the composite sieve plate B adopts the method of internal groove and external opening, as shown in Figure 6.

When the above-mentioned hydrophobic material surface adopts the method of combining grooves and openings, another optional implementation method is: the hydrophobic material surface of the composite sieve plate A adopts the method of internal grooves and external openings, as shown in Figure 6. The hydrophobic material surface of the sieve plate B adopts the method of external groove and internal opening, as shown in Figure 5.

When the oil phase in the extraction tower is the dispersed phase, in an embodiment of the present invention, the side of the composite sieve plate A and B facing the stirring section is a hydrophobic material surface, and the surface is evenly opened according to the aforementioned opening requirements, and evenly opened When making holes, the surface of the hydrophilic material should be opened or grooved at the position corresponding to the opening of the surface of the hydrophobic material, the diameter of the hole is 4.0-10.0mm, and the width of the groove is not less than the diameter of the hole on the surface of the hydrophobic material and not greater than 10.0mm , the slotting method is shown in Figure 3 or Figure 4.

Further, when the above-mentioned hydrophobic material surface is uniformly opened, the hydrophilic material surface adopts a combination of slotting and opening at the position corresponding to the hydrophobic material surface, the diameter of the hole is 4.0-10.0mm, and the groove width is not less than the hydrophobic material surface. The diameter of the hole on the surface of the material is not greater than 10.0mm, and the slotting and opening methods are shown in Figure 5 or Figure 6.

Further, when the surface of the above-mentioned hydrophilic material is combined with grooves and holes, an optional embodiment is: the surface of the hydrophilic material of the composite sieve plate A adopts the method of external grooves and internal openings, as shown in Figure 5 As shown, the hydrophilic material surface of the composite sieve plate B adopts the method of internal grooves and external openings, as shown in Figure 6.

When the surface of the above-mentioned hydrophilic material adopts the combination of slotting and opening, another optional embodiment is: the surface of the hydrophilic material of the composite sieve plate A adopts the method of internal slotting and external opening, as shown in Figure 6 , the hydrophilic material surface of the composite sieve plate B adopts the method of external grooves and internal openings, as shown in Figure 5.

Example 1

Composite sieve plate extraction tower as shown in Figure 1, diameter is 50mm, has 3 stirring sections and 4 clarification sections, stirring section height 35mm, clarification section height 50mm, the hydrophilic material of composite sieve plate A and B is stainless steel, The thickness is 1.0mm. The hydrophobic material of the composite sieve plates A and B is polytetrafluoroethylene, and the thickness is 1.0mm. When installing, the hydrophobic material faces of the composite sieve plates A and B face the mixing section, and the holes are evenly opened on the hydrophobic material surface A small hole with a diameter of 3.0mm and an opening rate of 10%. The surface of the composite sieve plate A is grooved on the outside with a groove width of 3.0mm, and the inside is opened with a diameter of 4.0mm. The surface of the water material is internally grooved with a groove width of 3.0mm, and the external hole is drilled with a diameter of 4.0mm. Taking the n-butanol-succinic acid-water system with low interfacial tension (the interfacial tension is 0.753mN/m) as the research object, the n-butanol solution with a mass fraction of succinic acid of 5% is pumped into the light phase inlet as a dispersion Phase, the heavy phase inlet is pumped into pure water as the continuous phase, the solvent ratio is 1, when the rotation speed is 130rpm, and the total flow rate of the two phases is 60mL/min, the theoretical extraction stage is 1.21, and the maximum flux of the extraction tower is 7.2m ³ /(m ² ·hr).

Example 2

Composite sieve plate extraction tower as shown in Figure 1, diameter is 50mm, has 3 stirring sections and 4 clarification sections, stirring section height 35mm, clarification section height 50mm, the hydrophilic material of composite sieve plate A and B is stainless steel, The thickness is 1.0mm, the hydrophobic material of the composite sieve plate A and B is polytetrafluoroethylene, the thickness is 1.0mm, the composite sieve plate A and B both face the hydrophobic material towards the stirring section, and the average opening diameter on the hydrophobic material surface is 3.0 mm small holes, the opening rate is 10%, the hydrophilic material surface of the composite sieve plate A is internally grooved, the groove width is 3.0mm, the external hole is 4.0mm in diameter, and the hydrophilic material surface of the composite sieve plate B is The outer groove is 3.0mm wide, and the inner hole is 4.0mm in diameter. Taking the n-butanol-succinic acid-water system with low interfacial tension (the interfacial tension is 0.753mN/m) as the research object, the n-butanol solution with a mass fraction of succinic acid of 5% is pumped into the light phase inlet as a dispersion Phase, the heavy phase inlet is pumped into pure water as the continuous phase, the solvent ratio is 1, when the rotation speed is 130rpm, and the total flow rate of the two phases is 60mL/min, the theoretical extraction stage is 1.13, and the maximum flux of the extraction tower is 7.2m ³ /(m ² ·hr).

Example 3

Composite sieve plate extraction tower as shown in Figure 1, diameter is 50mm, has 3 stirring sections and 4 clarification sections, stirring section height 35mm, clarification section height 50mm, the hydrophilic material of composite sieve plate A and B is stainless steel, The thickness is 0.5mm, the hydrophobic material of the composite sieve plates A and B is polytetrafluoroethylene, the thickness is 1.0mm, the composite sieve plates A and B both have the hydrophilic material facing the stirring section, and the uniform opening diameter on the hydrophilic material surface It is a small hole of 3.0mm, and the opening rate is 10%. The hydrophobic material surface of the composite sieve plate A is internally grooved, the groove width is 3.0mm, and the external opening is 4.0mm in diameter. The hydrophobic material surface of the composite sieve plate B is The outer groove is 3.0mm wide, and the inner hole is 4.0mm in diameter. Taking the n-butanol-succinic acid-water system with low interfacial tension (the interfacial tension is 0.753mN/m) as the research object, the n-butanol solution with a mass fraction of succinic acid of 5% is pumped into the light phase inlet as a continuous Phase, the heavy phase inlet is pumped into pure water as the dispersed phase, the solvent ratio is 1, when the rotation speed is 130rpm, and the total flow rate of the two phases is 60mL/min, the extraction theoretical stage is 1.17, and the maximum flux of the extraction tower is 10.8m ³ /(m ² ·hr).

Example 4

The composite sieve tray extraction tower shown in Figure 1 has a diameter of 100mm, a total of 6 stirring sections and 7 clarification sections, the height of the stirring section is 70mm, and the height of the clarification section is 80mm. The hydrophilic material of the composite sieve trays A and B is titanium. , the thickness is 1.0mm, the hydrophobic material of the composite sieve plate A and B is polypropylene, the thickness is 0.5mm, the composite sieve plate A and B both face the hydrophobic material towards the stirring section, and the uniform opening diameter of the hydrophobic material surface is 1.0mm For small holes, the opening rate is 30%, and the surface of the hydrophilic material is grooved at the corresponding opening position of the surface of the hydrophobic material, as shown in Figure 3, and the groove width is 1.5mm. Taking the decanol-tetradecane-ethanol-water system with low interfacial tension (the interfacial tension is 0.490mN/m) as the research object, the tetradecane solution with a mass fraction of decyl alcohol of 50% is pumped into the light phase inlet as a dispersion Phase, the heavy phase inlet is pumped into 65% ethanol aqueous solution as the continuous phase, the solvent ratio is 3, when the rotating speed is 40rpm, when the total flow rate of the two phases is 200mL/min, the extraction theoretical stage is 2.13, and the maximum flux of the extraction tower is 7.9m ³ /(m ² ·hr).

Example 5

The composite sieve tray extraction tower shown in Figure 1 has a diameter of 100mm, a total of 6 stirring sections and 7 clarification sections, the height of the stirring section is 70mm, and the height of the clarification section is 80mm. The hydrophilic material of the composite sieve trays A and B is titanium. , the thickness is 1.0mm, the hydrophobic material of the composite sieve plate A and B is polypropylene, the thickness is 1.0mm, the composite sieve plate A and B both face the hydrophobic material towards the stirring section, and the uniform opening diameter of the hydrophobic material surface is 4.0mm For small holes, the opening rate is 5%, and the surface of the hydrophilic material is grooved at the position corresponding to the opening of the surface of the hydrophobic material, as shown in Figure 4, and the groove width is 10.0mm. Taking the decanol-tetradecane-ethanol-water system with low interfacial tension (the interfacial tension is 0.490mN/m) as the research object, the tetradecane solution with a mass fraction of decyl alcohol of 50% is pumped into the light phase inlet as a dispersion Phase, the heavy phase inlet is pumped into 65% ethanol aqueous solution as the continuous phase, the solvent ratio is 3, when the rotating speed is 40rpm, when the total flow rate of the two phases is 200mL/min, the theoretical extraction stage is 2.21, and the maximum flux of the extraction tower is 8.2m ³ /(m ² ·hr).

Example 6

The composite sieve tray extraction tower shown in Figure 1 has a diameter of 100 mm, a total of 6 stirring sections and 7 clarification sections, the height of the stirring section is 70 mm, and the height of the clarification section is 80 mm. The hydrophilic materials of composite sieve plates A and B are aluminum sheets , the thickness is 1.0mm, the hydrophobic material of the composite sieve plate A and B is polyethylene, the thickness is 1.0mm, the composite sieve plate A and B both face the hydrophobic material towards the stirring section, and the uniform opening diameter of the hydrophobic material surface is 3.0mm For small holes, the opening rate is 10%. The surface of the hydrophilic material is opened at the position corresponding to the surface of the hydrophobic material. The diameter of the hole is 6.0mm. Taking the decanol-tetradecane-ethanol-water system with low interfacial tension (the interfacial tension is 0.490mN/m) as the research object, the tetradecane solution with a mass fraction of decyl alcohol of 50% is pumped into the light phase inlet as a dispersion Phase, the heavy phase inlet is pumped into 65% ethanol aqueous solution as the continuous phase, the solvent ratio is 3, when the rotating speed is 40rpm, when the total flow rate of the two phases is 200mL/min, the theoretical order of extraction is 2.35, and the maximum flux of the extraction tower is 7.6m ³ /(m ² ·hr).

Example 7

Composite sieve plate extraction tower as shown in Figure 1, diameter is 300mm, has 3 stirring sections and 4 clarification sections, stirring section height 120mm, clarification section height 180mm, the hydrophilic material of composite sieve plate A and B is stainless steel, The thickness is 10.0mm, the hydrophobic material of the composite sieve plate A and B is polytetrafluoroethylene, the thickness is 10.0mm, the composite sieve plate A and B both face the hydrophobic material surface to the stirring section, and the uniform opening diameter of the hydrophobic material surface is 4.0mm The small holes, the opening rate is 10%, the surface of the hydrophilic material is opened at the position corresponding to the opening of the surface of the hydrophobic material, and the diameter of the hole is 10.0mm. Taking the cyclohexane-isopropanol-water system with low interfacial tension (the interfacial tension is 1.396mN/m) as the research object, a cyclohexane solution with a mass fraction of isopropanol of 30% is pumped into the light phase inlet as a dispersion Phase, the heavy phase inlet is pumped into pure water as the continuous phase, the solvent ratio is 1, when the rotation speed is 24rpm, and the total flow rate of the two phases is 1500mL/min, the theoretical extraction stage is 1.32, and the maximum flux of the extraction tower is 12.9m ³ /(m ² ·hr).

Example 8

Composite sieve plate extraction tower as shown in Figure 1, diameter is 300mm, has 3 stirring sections and 4 clarification sections, stirring section height 120mm, clarification section height 180mm, the hydrophilic material of composite sieve plate A and B is stainless steel, The thickness is 4.0mm, the hydrophobic material of the composite sieve plate A and B is polytetrafluoroethylene, the thickness is 2.0mm, the composite sieve plate A and B both face the hydrophobic material surface to the stirring section, and the average opening diameter of the hydrophobic material surface is 2.0mm Small holes, the opening rate is 15%, the surface of the hydrophilic material is opened at the position corresponding to the opening of the surface of the hydrophobic material, and the diameter of the hole is 4.0mm. Taking the cyclohexane-isopropanol-water system with low interfacial tension (the interfacial tension is 1.396mN/m) as the research object, a cyclohexane solution with a mass fraction of isopropanol of 30% is pumped into the light phase inlet as a dispersion Phase, the heavy phase inlet is pumped into pure water as the continuous phase, the solvent ratio is 1, when the rotation speed is 24rpm, and the total flow rate of the two phases is 1500mL/min, the theoretical extraction stage is 1.47, and the maximum flux of the extraction tower is 13.6m ³ /(m ² ·hr).

Comparative Example 1

Keeping other parameters the same as in Example 1, only the materials on both sides of the composite sieve plate A and B are selected from stainless steel, and the n-butanol-succinic acid-water system with low interfacial tension (the interfacial tension is 0.753mN/m) is used as the research Object, pump into the n-butanol solution with succinic acid mass fraction of 5% from the light phase inlet, as the dispersed phase, pump into the pure water as the heavy phase inlet, as the continuous phase, the solvent ratio is 1, when the rotating speed is 130rpm, two phases When the total flow rate is 60mL/min, the theoretical extraction stage is 0.88, and the maximum throughput of the extraction tower is 3.5m ³ /(m ² ·hr).

Comparative Example 2

Keep other parameters the same as in Example 1, only polytetrafluoroethylene is selected for both sides of the composite sieve plate A and B, and the n-butanol-succinic acid-water system with low interfacial tension (interfacial tension is 0.753mN/m ) as the research object, pumped into the succinic acid mass fraction by the light phase inlet is 5% n-butanol solution, as the dispersed phase, the heavy phase inlet is pumped into pure water, as the continuous phase, the solvent ratio is 1, when the rotating speed is 130rpm , when the total flow rate of the two phases is 60mL/min, the theoretical order of extraction is 0.92, and the maximum throughput of the extraction tower is 3.9m ³ /(m ² ·hr).

Comparative Example 3

Keep other parameters the same as in Example 1, only change the direction of the material, make the hydrophilic material face towards the stirring section, and take the n-butanol-succinic acid-water system with low interfacial tension (the interfacial tension is 0.753mN/m) as the research object , the light phase inlet is pumped into succinic acid mass fraction and is 5% n-butanol solution, as the dispersed phase, and the heavy phase inlet is pumped into pure water, as the continuous phase, the solvent ratio is 1, when the rotating speed is 130rpm, the two-phase total When the flow rate is 60mL/min, the theoretical extraction stage is 0.81, and the maximum throughput of the extraction tower is 3.0m ³ /(m ² ·hr).

Comparative Example 4

Keep other parameters the same as in Example 1, only change the material orientation, make the hydrophobic material face all down, and take the n-butanol-succinic acid-water system (interfacial tension is 0.753mN/m) of low interfacial tension as the research object, Pump the n-butanol solution with succinic acid mass fraction of 5% from the light phase inlet, as the dispersed phase, and pump pure water into the heavy phase inlet, as the continuous phase, the solvent ratio is 1, when the rotating speed is 130rpm, the total flow rate of the two phases When it is 60mL/min, the extraction theoretical stage is 0.89, and the maximum throughput of the extraction tower is 3.8m ³ /(m ² ·hr).

Comparative Example 5

Keep other parameters the same as in Example 1, only change the opening mode of the hydrophilic material, so that the opening mode of the hydrophilic material surface and the hydrophobic material surface are completely consistent, with the n-butanol-succinic acid-water system of low interfacial tension ( The interfacial tension is 0.753mN/m) as the research object, pumped into the n-butanol solution of 5% succinic acid mass fraction by the light phase inlet, as the dispersed phase, and the heavy phase inlet is pumped into pure water, as the continuous phase, the solvent ratio is 1, when the rotational speed is 130rpm and the total flow rate of the two phases is 60mL/min, the theoretical extraction stage is 1.07, and the maximum throughput of the extraction tower is 3.3m ³ /(m ² ·hr).

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims (9)

1. The utility model provides a compound sieve extraction tower, its characterized in that comprises stirring section and clarification section in turn along the tower height direction, stirring section upper end is equipped with compound sieve A, the lower extreme is equipped with compound sieve B, compound sieve A and B's two sides are the material of two kinds of different hydrophilic and hydrophobic properties respectively, wherein one side is hydrophilic material, the another side is hydrophobic material, when the oil phase is the disperse phase in the extraction tower, compound sieve A and B's hydrophilic material face orientation clarification section, hydrophobic material face orientation stirring section, when the aqueous phase is the disperse phase in the extraction tower, compound sieve A and B's hydrophilic material face orientation stirring section, hydrophobic material face orientation clarification section.

2. The composite screen plate extraction column of claim 1, wherein the hydrophilic material is stainless steel, aluminum or titanium, and has a thickness of 0.5-10mm.

3. A composite screen plate extraction column as claimed in claim 1, wherein the hydrophobic material is polytetrafluoroethylene, polyethylene or polypropylene and has a thickness of 0.5-10mm.

4. The composite screen plate extraction tower as claimed in claim 1, wherein the side of the composite screen plates A and B facing the stirring section is provided with holes in a uniform manner, the diameter of the holes is 1.0-4.0mm, and the aperture ratio is 5-30%.

5. The composite screen panel extraction column as claimed in claim 4, wherein the side of the composite screen panels A and B facing the clarification section is perforated or grooved at a position corresponding to the perforation on the side facing the stirring section, the diameter of the perforation is 4.0-10.0mm, and the width of the groove is not smaller than the diameter of the perforation on the side facing the stirring section and not larger than 10.0mm.

6. The composite screen panel extraction column as claimed in claim 4, wherein the side of the composite screen panels A and B facing the clarification section is provided with grooves and openings at positions corresponding to the openings on the side facing the stirring section, the diameter of the holes is 4.0-10.0mm, and the width of the grooves is not less than the diameter of the holes on the side facing the stirring section and not more than 10.0mm.

7. The composite screen panel extraction column of claim 6, wherein the side of the composite screen panel a facing the clarifier section is open with an exterior slot and the side of the composite screen panel B facing the clarifier section is open with an interior slot and the exterior slot.

8. The composite screen panel extraction column of claim 6, wherein the side of the composite screen panel a facing the clarifier section is provided with an internal slotted external opening, and the side of the composite screen panel B facing the clarifier section is provided with an external slotted internal opening.

9. Use of a composite screen plate extraction column according to any one of claims 1 to 8 in the extraction of a low interfacial tension extraction system, i.e. a system with an interfacial tension of less than 3 mN/m.

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