CN217489808U

CN217489808U - Liquid distributor and extraction tower

Info

Publication number: CN217489808U
Application number: CN202220575291.7U
Authority: CN
Inventors: 鲍迪; 唐晓津; 任小甜; 朱振兴
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2022-03-16
Filing date: 2022-03-16
Publication date: 2022-09-27
Anticipated expiration: 2032-03-16

Abstract

A liquid distributor and an extraction tower, the liquid distributor is formed by sequentially connecting a main pipe (8), a connecting pipe (10) and a plurality of branch pipes (9); the branch pipes (9) are positioned on the same horizontal plane and are called as a branch pipe plane, the main pipe is parallel to the branch pipe plane and is positioned above or below the branch pipe plane, the connecting pipes are respectively and vertically connected with the main pipe and the branch pipes, and the branch pipes are provided with round holes at equal intervals. The liquid distributor is arranged in the extraction tower. The utility model provides an extraction tower is applicable to the heavy oil solvent deasphalting process, and the liquid distributor equipartition performance of installation in it is good, the handling capacity is big, difficult jam.

Description

Liquid distributor and extraction tower

Technical Field

The utility model relates to a reactor internals and splitter in oil refining and chemical industry field, more specifically say, relate to an extraction knockout tower and internals that is applied to solvent deasphalting process.

Background

Petroleum resources in the world show the trend of heavy oil conversion and poor oil conversion, environmental protection laws and regulations in various countries are increasingly strict, higher requirements are put on the light oil conversion and the cleanness of oil refining products and the cleanness and the low carbon of refining processes, and the heavy oil conversion technology is more and more emphasized. Solvent deasphalting is one of the important approaches for the conversion of heavy oil into light oil, residual oil can be separated to obtain the deasphalted asphalt rich in asphaltene and metals and high in carbon residue and the deasphalted oil with low impurity content and low carbon residue, and the combined process of the deasphalting and the deasphalted oil is very attractive in the aspect of deep processing of heavy oil.

The residual oil solvent deasphalting for producing light oil is to use heavy hydrocarbon such as pentane as solvent, remove all asphaltenes and most metals in heavy oil by using heavy solvent to obtain deasphalted oil with high yield, and carry out hydrogenation treatment on the deasphalted oil, wherein the deasphalted oil after hydrogenation can be used as catalytic cracking raw material or hydrocracking raw material, so as to realize high yield of light oil. It is expected that large solvent deasphalting equipment and technology with high deasphalted oil yield will play a greater role in heavy oil processing and bring higher economic benefits to enterprises in the environment of shortage of petroleum resources and increasing demand for petroleum products.

The liquid distributor in the solvent deasphalting extraction tower has the function of uniformly and initially distributing or redistributing liquid at one end of the filler section, and is used for improving the effective surface of mass transfer and heat transfer, improving interphase contact and further improving the efficiency of the tower. The quality of the initial distribution of liquid not only affects the mass transfer efficiency of the packing, but also affects the operational flexibility of the packing. Therefore, the liquid distributor is a very critical internal piece in the packed column.

CN211111876U discloses a liquid distributor, which comprises a horizontal main pipe, an inclined branch pipe and a branch pipe, wherein the branch pipe is provided with a circular small hole, and the inclined pipe design enhances the mobility of heavy hydrocarbon oil, so that the pipe has a self-flushing function, thereby facilitating the flow of heavy oil and particulate matters, and preventing the particulate matters from blocking and depositing in the pipe to affect the liquid distribution. CN1406654A discloses a novel liquid distributor comprises upper and lower two-layer, and upper and lower two-layer branch pipe corresponds with upper and lower two-layer horizontal house steward respectively and links to each other, opens the circular aperture that has the aperture inequality on the branch pipe, and the aperture is along with the increase of the distance from the feed inlet and crescent, can avoid a large amount of wall flows, channeling and the emergence of foam smuggleing the phenomenon secretly. CN103816845A discloses a liquid distributor, in which each distribution branch pipe and each liquid outlet branch pipe are filled with metal plates, and a shunting hole is formed between them and the pipe wall, so that the liquid distribution is more uniform. CN110142004A discloses a calandria drip type liquid distributor, the distribution branch pipe is provided with small holes and is provided with a liquid guide plate, liquid drips along the flow guide sawteeth and is sprayed to the packing layer, the working condition of ultra-low spraying density of liquid can be met, and the influence caused by liquid level fluctuation is avoided.

Most of the existing liquid distributors are disperse phase distributors, the processing capacity is low, and the distribution requirement of a large-flux continuous phase is difficult to meet. In addition, in order to meet the distribution performance under special working conditions, the existing distributor usually adopts non-uniform design, such as pipeline inclination, non-uniform hole distribution, selective addition of inner members at orifices and the like, so that the operation elasticity of the distributor is usually sacrificed to a certain extent, and the phenomenon of non-uniform liquid distribution can occur under the condition that the liquid flow is greatly changed.

Disclosure of Invention

The utility model discloses one of the technical problem that solves provides a liquid distributor on the basis among the prior art, and this liquid distributor's equipartition performance is good, the handling capacity is big, difficult jam.

The second technical problem to be solved by the utility model is to provide an extraction tower for installing the liquid distributor.

On the first hand, the utility model provides a liquid distributor, which is composed of a main pipe 8, a connecting pipe 10 and a plurality of branch pipes 9 which are connected in sequence; the branch pipes 9 are located on the same horizontal plane, which is called a branch pipe plane, the main pipe is parallel to the branch pipe plane and is located above or below the branch pipe plane, the connecting pipes are respectively and vertically connected with the main pipe and the branch pipes, and the branch pipes are provided with round holes at equal intervals.

In a second aspect, the utility model provides an extraction tower, wherein a raw material distributor is arranged in the middle of the extraction tower, an extraction solvent distributor is arranged at the bottom of the extraction tower, coalescent filler is filled between the top of the extraction tower and the raw material distributor, extraction structured filler is filled between the raw material distributor and the extraction solvent distributor, an extraction phase outlet is arranged at the top of the extraction tower, and an extraction raffinate phase outlet is arranged at the bottom of the extraction tower; the raw material distributor is any one of the liquid distributors, wherein the main pipe is positioned above the plane of the branch pipe; the extraction solvent distributor is any one of the liquid distributors, wherein the main pipe is positioned below the plane of the branch pipe.

Compared with the prior art, the utility model provides a solvent deasphalting extraction tower and beneficial effect of internals thereof does:

the liquid distributor and the extraction tower provided by the utility model have the advantages that the branch pipes of the raw material distributor are uniformly distributed with the open pores, so that the liquid can be uniformly distributed in the container, and the liquid distributor and the extraction tower have higher operation elasticity; the extraction solvent distributor branch pipe is evenly provided with the openings and the flow guide pipe, the baffle plate is arranged above the flow guide pipe, the backflow of dispersed phase liquid drops can be effectively prevented, and the distribution requirement of a large-flux continuous phase can be met.

The utility model provides an extraction tower is particularly useful for solvent desorption pitch technology, can show improvement solvent extraction efficiency. The extraction tower has simple structure, convenient and fast installation, high extraction and separation efficiency and large flooding flux.

Drawings

Fig. 1 is a schematic structural view of a first embodiment of a liquid distributor.

Fig. 2 is a schematic structural diagram of a second embodiment of a liquid distributor.

FIG. 3 is a schematic view of a partial structure of a branch pipe with a draft tube and a baffle.

FIG. 4 is a schematic view of the structure of an extraction column.

Fig. 5 is a schematic view of the structure of the liquid distributor used in comparative example 1.

Description of reference numerals:

1-extract phase outlet 2-shell

3-coalescence regular packing 4-raw material distributor

5-extraction structured packing 6-extraction solvent distributor

7-raffinate phase outlet 8, 11-main pipe

9. 12-branch pipe 10-connecting pipe

13-baffle plate of extraction solvent distributor 14-guide pipe of extraction solvent distributor

15-open pore

Detailed Description

The following specifically describes embodiments of the present invention. In the specification, the reference to the "top" refers to the 95-100% position range of the container from bottom to top, the reference to the "middle" refers to the 40-60% position range of the container from bottom to top, and the reference to the "bottom" refers to the 0-5% position range of the container from bottom to top.

In a first aspect, the utility model provides a liquid distributor, which is composed of a main pipe 8, a connecting pipe 10 and a plurality of branch pipes 9 which are connected in sequence; the branch pipes 9 are located on the same horizontal plane and are called as a branch pipe plane, the main pipe is parallel to the branch pipe plane and is located above or below the branch pipe plane, the connecting pipes are respectively and vertically connected with the main pipe and the branch pipes, and the branch pipes are provided with round holes at equal intervals.

Preferably, the branch pipes are arranged in parallel, and the main pipe is perpendicular to the branch pipes.

Preferably, the number of the branch pipes is 2-16, and the distance between the branch pipes is not less than 200 mm.

Preferably, the branch pipe is provided with a plurality of rows of round holes at equal intervals, each row is provided with a plurality of round holes, and the number of the round holes in two adjacent rows is the same or different.

Preferably, the inner diameter of the main pipe is 150-600mm, the inner diameter of the branch pipe is 50-200mm, or the ratio of the inner diameter of the branch pipe to the inner diameter of the main pipe is 1.5-8: 1.

the utility model provides an application method of liquid distributor, liquid material get into liquid distributor through the entry and are responsible for, upwards or during the branch pipe that gets into many parallels of each other downwards through the connecting pipe, liquid material disperses into the droplet through the round hole on the branch pipe, and the homodisperse is to the extraction tower in.

In a second aspect, the utility model provides an extraction tower, the middle part of the extraction tower is provided with a raw material distributor, the bottom of the extraction tower is provided with an extraction solvent distributor, coalescence packing is filled between the tower top and the raw material distributor, extraction structured packing is filled between the raw material distributor and the extraction solvent distributor, the top of the extraction tower is provided with an extraction phase outlet, and the bottom of the extraction tower is provided with a raffinate phase outlet; the raw material distributor is any one of the liquid distributors, wherein the main pipe is positioned above the plane of the branch pipe; the extraction solvent distributor is any one of the liquid distributors, wherein the main pipe is positioned below the plane of the branch pipe.

In the extraction tower provided by the utility model, preferably, the height to diameter ratio of extraction tower is 2 ~ 6:1, and the distance of extraction regular packing bottom and the bottom of the tower is 0.5 ~ 5m, preferably 3 ~ 5 m.

The utility model provides an in the extraction tower, raw materials distributor with extraction solvent distributor's well branch pipe the same or different in structure, because the mounted position in the extraction tower is different, the feeding volume through liquid distributor is different, preferred raw materials distributor with extraction solvent distributor's concrete structure different.

In the raw material distributor, the pipe diameter ratio of the main pipe to the branch pipes is 1.5-3: 1, and preferably 2-2.5: 1. The number of the branch pipes is 2-12, the distance between the branch pipes is not less than 200mm, multiple rows of round holes are formed in the branch pipes at equal intervals, each row of the round holes is provided with 2-3 round holes, the diameter of each round hole is 5-15 mm, and the included angle between the opening direction and the vertical direction is-30 degrees.

In the extraction solvent distributor, the pipe diameter ratio of the main pipe to the branch pipes is 3-8: 1, and preferably 4-6: 1. The quantity of branch pipe be 2 ~ 16, the branch pipe interval is not less than 200mm, equidistantly on the branch pipe open have a plurality of round holes, the round hole diameter is 8 ~ 30mm, the trompil direction is vertical upwards, the percent opening on the branch pipe is 1 ~ 5 thousandths.

In the using process, the lower aperture ratio can ensure higher spraying speed, ensure higher operation elasticity and simultaneously ensure that the solvent can be uniformly distributed.

In the extraction solvent distributor, preferably, each opening of the branch pipe of the extraction solvent distributor is provided with a flow guide pipe, the inner diameter of each flow guide pipe is not less than the diameter of the opening, and the difference between the two diameters is 0-5 mm. The length of the guide pipe is 2-5 times of the inner diameter of the guide pipe.

And a baffle plate is arranged above the flow guide pipe. The baffle is a conical, triangular or trapezoidal baffle, and the width of the baffle is the same as the diameter of the branch pipe. Preferably, the baffle is provided with a pore. When the baffle plate is provided with the round hole, the diameter of the round hole is 3-8 mm, and the aperture ratio is 10-30%; or the baffle is provided with a narrow slit, the width of the slit is 10-50 mm, the interval of the slit is 1-5 times of the distance between two adjacent guide pipes, the baffle can prevent dispersed phase liquid drops from entering the extraction solvent distributor, and meanwhile, the impact of the solvent on a filler bed layer can be avoided, and the phenomena of bias flow and channeling are avoided.

The utility model provides an application method of extraction tower, liquid raw materials get into the liquid distributor who is located the extraction tower middle part through the entry and are responsible for, upwards or during the branch pipe that gets into many parallels of each other downwards through the connecting pipe, become the droplet through the round hole homodisperse on the branch pipe, flow downwards in getting into the extraction tower. The liquid solvent enters an extraction solvent distributor positioned at the lower part of the extraction tower, is sprayed out through round holes and a flow guide pipe on a branch pipe, is uniformly distributed to the extraction tower through a baffle plate above the flow guide plate and flows upwards, the liquid raw material and the solvent are in countercurrent contact in an extraction regular packing section in the extraction tower, lighter components such as saturated components, aromatic components, colloid and the like in the raw material are transferred to a solvent main body through the surface of liquid drops and flow upwards to the top of the extraction tower along with the solvent, and flow out of the extraction tower through an extraction phase outlet at the top of the extraction tower, and residual heavier components such as asphaltene and partial colloid in the raw material are gathered at the bottom of the extraction tower and flow out of the extraction tower through a raffinate phase outlet at the bottom of the extraction tower; after entering the extraction tower from the raw material distributor, part of small liquid raw material drops are carried to the coalescence regular packing section above the raw material distributor by the solvent, are gathered into large drops or liquid films on the surface of the packing, and then flow downwards to return to the extraction regular packing section and the bottom of the extraction tower.

The utility model provides an extraction tower is applicable to agent deasphalting technology and removes asphalt extraction tower as solvent, wherein, the operating temperature of solvent deasphalting extraction tower is 50 ~ 190 ℃, and operating pressure is 4.0 ~ 5.5MPa, and the mass ratio of solvent and residual oil is 1.5 ~ 5: 1.

The following describes the embodiments of the solvent deasphalting extraction tower and its internal components with reference to the drawings, but the present invention is not limited thereto.

Fig. 1 is a schematic structural diagram of a first embodiment of a liquid distributor according to the present invention. As shown in fig. 1, the liquid distributor is composed of a main pipe 8, a connecting pipe 10 and a plurality of branch pipes 9 which are connected in sequence; the branch pipes 9 are positioned on the same horizontal plane and are parallel to each other, and the axial directions of the branch pipes are vertical to the axial direction of the main pipe; the main pipe is located above the plane of the branch pipe and is parallel to the plane of the branch pipe, the connecting pipes 10 are respectively and vertically connected with the main pipe and the branch pipe, and the branch pipe is provided with round holes at equal intervals. In the embodiment shown in fig. 1, the connecting pipe is a flange structure, and the main pipe and the branch pipe are connected through a flange; the branch pipe is provided with a plurality of rows of round holes 15 at equal intervals, each row is provided with a plurality of round holes, and the number of the round holes in two adjacent rows is equal or unequal.

Fig. 2 is a schematic structural diagram of a second embodiment of the liquid distributor according to the present invention. As shown in fig. 2, unlike the embodiment of fig. 1, the main pipe is located below and parallel to the plane of the branch pipes; the branch pipe is provided with a plurality of rows of round holes 15 at equal intervals, each row is provided with a plurality of round holes, and the number of the round holes in two adjacent rows is equal or unequal.

As shown in fig. 3, the branch pipe is provided with a plurality of round holes at equal intervals and a flow guide pipe 14; a conical, triangular or trapezoidal baffle 13 is arranged above the flow guide pipe, and a round hole or a narrow slit can be formed on the baffle.

Fig. 4 is a schematic structural diagram of the extraction tower provided by the present invention. As shown in fig. 4, the extraction column is composed of a shell 2, a raw material distributor 4 located in the middle of the shell, an extraction solvent distributor 6 located in the lower part, an overhead extraction phase outlet 1, a bottom raffinate phase outlet 7 and structured packing. Wherein, an extraction regular packing 5 is filled between the raw material distributor 4 and the extraction solvent distributor 6 for dispersing liquid drops and strengthening mass transfer, and the raw material distributor is made of stainless steel with smooth surface; and a coalescence regular packing 3 is filled between the raw material distributor and the tower top and is used for promoting liquid drops to coalesce and accelerating two-phase separation, and the material is stainless steel with passivated surface and is required to have stronger affinity to asphaltene and weaker affinity to a solvent.

The effect of the liquid distributor and the extraction column provided by the present invention will be further illustrated by the following examples, but the present invention is not limited thereto.

Comparative example 1

Illustrating the technical effect of using the existing liquid distributor in the residual oil solvent deasphalting extraction tower.

The solvent deasphalting extraction tower has inner diameter of 5m, tangent height of 19m, material distributor in the middle part, extracting solvent distributor in the bottom, coalescence stuffing filled from the top to the material distributor, and extracting stuffing filled from the material distributor to the extracting solvent distributor. Raw materials distributor and extraction solvent distributor adopt current liquid distributor, the structure is as shown in figure 4, liquid distributor comprises being responsible for and the branch pipe, the branch pipe passes through flange joint and is responsible for on the lateral wall to be 90 degrees contained angles with being responsible for, wherein, the diameter of being responsible for of raw materials distributor is 350mm, the branch pipe diameter is 150mm, total 20 branch pipes, it has 24 rows to be responsible for the bottom to open, 4 diameters of every row are 8 mm's circular aperture, the branch pipe bottom is opened has every row 3, 1530 diameters are 8 mm's circular aperture altogether. In the extraction solvent distributor, the diameter of a main pipe is 500mm, the diameter of a branch pipe is 60mm, 50 branch pipes are arranged in total and are connected to the side wall of the main pipe through a flange, and 11555 circular small holes with the diameter of 12mm are arranged at the bottoms of the main pipe and the branch pipes in total;

the extraction tower is applied to a solvent deasphalting process, the raw material is vacuum residue, the raw material flows in from the middle upper part of the tower, the extraction solvent is n-pentane, the raw material flows in from the middle lower part of the tower, the mass ratio of the extraction solvent to the vacuum residue is 3:1, the flow rate of the vacuum residue is 66.138kg/s, the residence time of the vacuum residue in an extraction section is 20min, and light and heavy phases are in countercurrent flow contact in the tower.

The analysis and test method comprises the following steps:

and measuring by using an Electrical Resistance Tomography (ERT) technology to obtain the distribution of the phase content of a certain section in the reactor, and further calculating by using a statistical principle to obtain the distribution unevenness of the phase content.

And measuring by adopting a high-speed camera shooting technology to obtain the average diameter of the dispersed phase particles.

Experimental data show that the residual oil distribution unevenness at the position 1m below the raw material distributor is 0.759, and the average diameter of liquid drops is 4.58 mm; the solvent distribution unevenness was 0.681 at 1m above the extraction solvent distributor.

Example 1

The application effect of the extraction tower provided by the utility model is demonstrated in the residual oil solvent deasphalting process.

The structure of the extraction tower is shown in figure 5, the inner diameter of the extraction tower is 5m, the tangent height is 19m, the middle part of the extraction tower is provided with a raw material distributor, the bottom of the extraction tower is provided with an extraction solvent distributor, coalescence packing is filled between the tower top and the raw material distributor, and extraction packing is filled between the raw material distributor and the extraction solvent distributor. Raw materials distributor and extraction solvent distributor adopt the utility model provides a liquid distributor, wherein raw materials distributor is shown as figure 1, is responsible for diameter 350mm, branch pipe diameter 150mm, total 10 branch pipes are connected in the person in charge bottom through the connecting pipe, the branch pipe bottom is opened has every row 2 ~ 3, 1628 diameter is 8 mm's circular aperture altogether. The structure of extraction solvent distributor is shown in figure 2, is responsible for diameter 550mm, and the branch pipe passes through the connecting pipe and connects at the top of being responsible for, branch pipe diameter 100mm, 13 total branch pipes, and the branch pipe top is opened 691 circular aperture that the diameter is 10mm altogether, and the trompil top is equipped with the internal diameter and is 10mm, length is 20 mm's honeycomb duct, and the honeycomb duct top is equipped with the triangle-shaped baffle that the width is 100mm, and it has the gap that the width is 20mm to open every 280mm in the middle of the baffle.

Experimental data show that the residual oil distribution unevenness at the position 1m below the raw material distributor is 0.178, and the average diameter of liquid drops is 3.20 mm; the solvent distribution unevenness at 1m above the extraction solvent distributor was 0.402.

Example 2

The same solvent deasphalting extraction column as in example 1 was used.

The flow rate of vacuum residue was 39.683kg/s, and other operating conditions were the same as in example 1. Experimental data show that the residual oil distribution unevenness at the position 1m below the raw material distributor is 0.170, and the average diameter of liquid drops is 3.91 mm; the solvent distribution unevenness at 1m above the extraction solvent distributor was 0.559.

Example 3

A solvent deasphalting extraction column similar to that of example 1 was used, except that a trapezoidal baffle having a width of 100mm was provided above the draft tube, 4735 circular holes having a diameter of 6mm were formed in the baffle, and other operating conditions were the same as those of example 1. Experimental data show that the residual oil distribution unevenness at the position 1m below the raw material distributor is 0.178, and the average diameter of liquid drops is 3.20 mm; the solvent distribution unevenness at 1m above the extraction solvent distributor was 0.331.

Claims

1. A liquid distributor is characterized by being formed by sequentially connecting a main pipe (8), a connecting pipe (10) and a plurality of branch pipes (9); the branch pipes (9) are positioned on the same horizontal plane and are called as a branch pipe plane, the main pipe is parallel to the branch pipe plane and is positioned above or below the branch pipe plane, the connecting pipes are respectively and vertically connected with the main pipe and the branch pipes, and the branch pipes are provided with round holes at equal intervals.

2. The liquid distributor according to claim 1, wherein the plurality of branch pipes are arranged in parallel, and the main pipe is perpendicular to the branch pipes.

3. The liquid distributor according to claim 1, wherein the number of said branch pipes is 2 to 16, and the pitch of said branch pipes is not less than 200 mm.

4. A liquid distributor according to claim 1 or 2, wherein the branch pipes are provided with a plurality of rows of circular holes at equal intervals, each row is provided with a plurality of circular holes, and the number of the circular holes in two adjacent rows is the same or different.

5. The liquid distributor according to claim 1 or 2, wherein the inner diameter of the main pipe is 150-600mm, the inner diameter of the branch pipe is 50-200mm, or the ratio of the inner diameter of the main pipe to the inner diameter of the branch pipe is 1.5-8: 1.

6. an extraction tower is provided, wherein a raw material distributor is arranged in the middle of the extraction tower, an extraction solvent distributor is arranged at the bottom of the extraction tower, coalescence packing is filled between the tower top and the raw material distributor, extraction structured packing is filled between the raw material distributor and the extraction solvent distributor, an extraction phase outlet is arranged at the top of the extraction tower, and an extraction raffinate outlet is arranged at the bottom of the extraction tower; characterized in that the material distributor is a liquid distributor according to any one of claims 1 to 5, wherein the main pipe is located above the plane of the branch pipes; the extractor solvent distributor is a liquid distributor as claimed in any one of claims 1 to 5, wherein the main pipe is located below the plane of the branch pipes.

7. The extraction column according to claim 6, wherein the height-diameter ratio of the extraction column is 2-6: 1, and the distance between the bottom of the extraction structured packing and the tangent line at the bottom of the extraction column is 0.5-5 m.

8. The extraction tower according to claim 6 or 7, wherein in the raw material distributor, the ratio of the pipe diameters of the main pipes to the branch pipes is 1.5-3: 1, the number of the branch pipes is 2-12, the distance between the branch pipes is not less than 200mm, a plurality of rows of round holes are arranged on the branch pipes at equal intervals, each row has 2-3 round holes, the diameter of each round hole is 5-15 mm, and the included angle between the opening direction and the vertical direction is-30 °.

9. The extraction column according to claim 8, wherein a tube diameter ratio of the main tube to the branch tubes in the raw material distributor is 2 to 2.5: 1.

10. The extraction column according to claim 6 or 7, wherein in the extraction solvent distributor, the ratio of the pipe diameters of the main pipe and the branch pipes is 3-8: 1, the number of the branch pipes is 2-16, the distance between adjacent branch pipes is not less than 200mm, the branch pipes are provided with holes with the diameters of 8-30 mm at equal intervals, the hole opening direction is vertical upward, and the hole opening rate of the branch pipes is 1-5 per mill.

11. The extraction column according to claim 10, wherein the ratio of the main pipe to the branch pipe in the extraction solvent distributor is 4 to 6: 1.

12. The extraction column as claimed in claim 10, wherein said extraction solvent distributor has a flow guide tube at the opening of the branch tube, and a baffle plate is provided above said flow guide tube.

13. The extraction column according to claim 12, wherein the baffle plate has pores therein, and the opening ratio is 10 to 30%.