A filler monomer, a filler component and its application in a liquid-liquid extraction system

Abstract

The present invention discloses a packing monomer, which is a hollow truncated regular octahedron structure, formed by 8 regular hexagons and 6 regular quadrilaterals, wherein the upper and lower two regular hexagons are closed planes, and the 6 regular quadrilaterals and 6 regular hexagons on the side have openings to form twelve flow channels. The present invention also discloses a packing assembly, including a packing body with a three-dimensional mesh structure, the packing body is composed of a plurality of the packing monomers arranged and combined, and adjacent packing monomers are interconnected by aligning the regular quadrilaterals on the side, the regular hexagons on the side, or the upper and lower regular hexagons, wherein the upper and lower adjacent packing monomers are not connected because the regular hexagon on the top of the packing monomer located below is closed, and the remaining adjacent packing monomers are connected to each other through flow channels, and are arranged in a high and low manner. The present invention also provides the use of the packing assembly in a liquid-liquid extraction system.

Description

Technical Field

[0001] The invention relates to the technical field of chemical separation, and in particular to a filler monomer, a filler component and application thereof in a liquid-liquid extraction system. Background Art

[0002] The packed tower is an important liquid-liquid extraction equipment with the characteristics of simple structure, easy installation and high separation efficiency. The packed tower is mainly composed of packing, tower internals and cylinder, which work together to achieve mass transfer and separation effect. Among them, the packing is the most core component in the tower. It is the contact place for effective mass transfer and heat transfer between the two phases, which is directly related to the mass transfer performance and separation efficiency of the packed tower. The main types of packing currently used in industry include: random packing and structured packing.

[0003] Random packing is irregularly stacked in the tower, the liquid-liquid contact is relatively sufficient, and the mass transfer effect of the packing is good. The disadvantage is that the stacking shape cannot be controlled, and there are unfavorable conditions such as channel flow and wall collection, and the requirements for fluid distribution are relatively high. For high-density differential extraction systems, step rings are a commonly used random packing configuration. Due to the directional effect of the flange structure, the directional arrangement of the packing is improved, the movement of the fluid in the packing is more regular, the resistance is reduced, the flux is increased, and the mass transfer efficiency is improved. Patent CN891091512.1 discloses a flat ring packing with a unique inward curved arc rib structure, which eliminates the flange of the step ring, making the dispersed phase distribution in the tower more uniform, and promoting the fragmentation-coalescence-fragmentation of the dispersed phase droplets in the packing. Patent CN210229985U discloses a high-efficiency reinforced saddle ring packing, which not only has strong strength, but also has a larger specific surface area, thereby improving the mass transfer efficiency. Patent CN00200232.9 discloses a flat ring packing with inwardly curved arc ribs and reinforced sawtooth windows, which overcomes the serious axial back-mixing problem of liquid-liquid extraction system.

[0004] Compared with random packing, structured packing presents a regular geometric arrangement, strong periodicity of fluid movement, low pressure drop, and large mass transfer area. Typical structured packings include: grid packing, wire mesh packing, Mellapack structured packing, SMVP structured packing, multi-channel packing, etc. Among them, Sulzer's Mellapack packing is the most widely used. It has a staggered multi-channel symmetrical structure, which can promote the dispersion-coalescence-redispersion of the liquid phase and ensure the continuous renewal of the mass transfer surface, thereby obtaining higher efficiency and extremely large flux. Patent CN110449113A proposes a high-efficiency structured packing composed of staggered beveled edge packing and straight edge packing. The two-phase flow channel between adjacent packing layers is more unobstructed, the flow resistance is reduced, the packing wetting area is increased, the two-phase contact is more sufficient, and the specific surface area of ​​the packing is effectively increased. Patent CN210078931U proposes a wave curved surface guide structured packing, the channel wall is a wave curved surface, and each layer of packing units is placed crosswise with the adjacent layer, which improves the packing's ability to prevent clogging. Patent CN200610053562.8 discloses a plate corrugated structured packing, which is composed of multiple layers of inclined plate corrugations. There is an axially guided plate corrugated structured packing layer between every two layers of inclined plate corrugated structured packing, which effectively improves the two-phase flow characteristics and enhances the interphase mixing effect.

[0005] The extraction packed tower uses the density difference or gravity difference between the two phases to achieve countercurrent flow and mass transfer. The existing packing configuration is mainly for the small density difference between the two phases (<200kg / m 3 ). When the density difference of the liquid-liquid system is large, the heavy phase tends to fall quickly, resulting in a short contact time between the two phases, making it difficult for the dispersed phase to be highly dispersed, and the mass transfer performance deteriorates. Therefore, it is necessary to design a new configuration packing suitable for high-density-difference liquid-liquid extraction and separation systems to ensure efficient dispersion of the dispersed phase in the packing and sufficient contact between the two phases. Summary of the invention

[0006] In view of the deficiencies in the art, the present invention provides a filler monomer and a filler assembly composed of the filler monomer, which is particularly suitable for a liquid-liquid two-phase extraction system, can ensure efficient dispersion of the dispersed phase and full contact between the liquid-liquid two phases, reduce adverse conditions such as short circuits and channeling, and effectively increase the extraction mass transfer efficiency.

[0007] A filler monomer is a hollow truncated regular octahedron structure, formed by 8 regular hexagons and 6 regular quadrilaterals, wherein the upper and lower two regular hexagons are closed planes, and the 6 regular quadrilaterals and 6 regular hexagons on the side have openings to form twelve flow channels.

[0008] The bottom regular hexagon of the filler monomer may also be opened with holes, and when the filler monomers are piled up to form a filler assembly, the sealed regular hexagonal plane on the top of the lower filler monomer can be used to separate the upper and lower filler monomers.

[0009] Preferably, the twelve flow channels are evenly distributed along different side directions, and the cross-sections of the flow channels are regular hexagons or regular quadrilaterals respectively.

[0010] The present invention also provides a packing assembly, comprising a packing body with a three-dimensional network structure, wherein the packing body is composed of a plurality of the packing monomers arranged and combined, and adjacent packing monomers are connected to each other by aligning the side regular quadrilaterals, the side regular hexagons or the upper and lower regular hexagons, wherein the upper and lower adjacent packing monomers are not connected due to the closed regular hexagon on the top of the packing monomer located below, and the remaining adjacent packing monomers are connected to each other through flow channels and are arranged in a staggered manner.

[0011] The packing monomers are arranged in arrays along three orthogonal directions to form a packing body with a three-dimensional network structure having regular fluid channels. The dividing surfaces between adjacent basic units are opposite to each other, the holes are opposite to each other, and the flow channels are opposite to each other.

[0012] The packing component can achieve the following two technical effects due to the particularity of its structure: 1. The packing monomers with truncated regular octahedral structure can be densely stacked to completely fill the three-dimensional space to form a three-dimensional frame, avoiding space waste and ensuring good dispersion of the dispersed phase; 2. The packing component has a horizontal partition plate (a regular hexagonal closed plane on the top of the packing monomer) to increase the residence time of the dispersed phase. The horizontal partition structure in the packing monomer can effectively alleviate the falling speed of the heavy dispersed phase, increase the contact area between the two phases, prevent short circuit and channeling, and enhance the two-phase mass transfer extraction.

[0013] Preferably, the packing body is cylindrical.

[0014] Preferably, the top and bottom of the filler body are provided with reinforcing ribs for improving the packing body's resistance to stamping and deformation.

[0015] Preferably, the packing assembly further comprises an outer wall surrounding the packing body on the side, and the outer wall is provided with a plurality of through holes connected with the flow channel of the packing body. The outer wall is provided with a plurality of through holes, which penetrate the wall surface and are connected with the flow channel in the three-dimensional mesh packing body, and the fluid can enter and exit the packing through these through holes to ensure smooth flow of the fluid.

[0016] The invention also provides application of the filler component in a liquid-liquid extraction system.

[0017] During the extraction process, the fluid flows in the filler, and the filler has channels that meet the distribution and movement of the fluid. In the new configuration filler proposed by the present invention, the flow channels are distributed as follows: first, the regular quadrilateral area openings in each wrapped surface of the basic unit body (filler monomer) are set as fluid channels (flow channels); secondly, the 6 regular hexagonal planes on the side are also opened (preferably regular hexagonal holes are opened in the center of the plane) to form flow channels, and these twelve flow channels are evenly distributed along different side directions; finally, the interior of the basic unit body is a hollow structure, and the hollow area is connected to the adjacent basic unit bodies through the twelve flow channels arranged around the periphery, and the basic unit bodies connected to each other are arranged in a staggered height.

[0018] In the packing assembly, the upper and lower surfaces of the basic unit body (the lower surface may be the top surface of the lower basic unit body connected thereto) are in a closed state. During the extraction process, the liquid phase is divided into multiple liquid phases in the packing monomer and enters different channels respectively. The upper and lower horizontal partitions of the basic unit body act as fluid barriers, reduce the vertical movement of the fluid, strengthen the fluid deflection and dispersion, increase the contact time between the two phases, and improve the mass transfer efficiency.

[0019] Preferably, the density difference between the two phases in the liquid-liquid extraction system is not less than 200 kg / m 3 The packing assembly of the present invention is particularly suitable for high density difference (≥200kg / m 3 )Liquid-liquid extraction system.

[0020] Preferably, the packing assembly has the same plane size as the extraction tower, and is installed in the extraction tower in a single or multiple layers. The packing assembly is used in a layered manner to meet any separation height and theoretical separation stage requirements.

[0021] The height of the packing assembly is preferably 50 to 1000 mm, and more preferably 100 to 300 mm.

[0022] Compared with the prior art, the main advantages of the present invention include: a hollow truncated octahedron structure is selected as the basic unit body, which can effectively fill the three-dimensional space; the heavy dispersed phase enters the high-density differential liquid-liquid extraction regular packing from top to bottom; as the heavy dispersed phase flows, it enters the packing monomer through the channel and is cut into multiple liquid flows in different directions, resulting in good spatial dispersion of the dispersed phase and improving the uniformity of liquid flow distribution in the packing; the horizontal separation structure plays a role in buffering the heavy dispersed phase, resulting in the aggregation of the dispersed phase in the packing unit, slowing down the falling speed, increasing the contact time between the two phases, increasing the retained dispersion, and improving the mass transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of the three-dimensional structure of a filler monomer of an embodiment;

[0024] Figure 2is a schematic diagram of the three-dimensional structure of the packing assembly of the embodiment;

[0025] Figure 3 It is a partial enlarged structural schematic diagram of the packing assembly of the embodiment;

[0026] Figure 4 A schematic diagram of a process of constructing a packing assembly from a packing monomer of an embodiment;

[0027] In the figure: 11-regular hexagonal closed plane, 12-regular quadrilateral fluid channel, 13-regular hexagonal fluid channel, 14-filler monomer side filler, 1-filler body, 2-reinforcement ribs, 3-outer wall. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and specific examples. It should be understood that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention. The operating methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0029] Example

[0030] like Figure 1 As shown, the filler monomer used in this embodiment is a hollow truncated regular octahedron structure, which is formed by 8 regular hexagons and 6 regular quadrilaterals, of which the upper and lower two are regular hexagonal closed planes 11 (filler monomer horizontal separation structure), and the 6 regular quadrilaterals and 6 regular hexagonal openings on the side form twelve flow channels, which are 6 regular quadrilateral fluid channels 12 and 6 regular hexagonal fluid channels 13. The twelve flow channels are evenly distributed along different side directions. Specifically, the side wall thickness of the filler monomer is 0.5mm, and the edge length R of the regular hexagonal closed plane 11, the regular quadrilateral fluid channel 12, and the side filler 14 is equal to 4mm; the regular hexagonal fluid channel 13 opens a regular hexagonal hole in the center of the side filler 14, and the edge length L of the opening is 2.8mm.

[0031] The process of assembling the above-mentioned filler monomers to form a filler assembly is as follows: Figure 4As shown, multiple packing monomers are combined and arranged in an array along three orthogonal directions. In order to be suitable for a cylindrical extraction tower, the obtained rectangular parallelepiped configuration is cut and stretched to form a cylindrical packing body with a three-dimensional mesh structure having a regular fluid channel, and then the cylindrical outer wall is surrounded on the side of the cylindrical packing body and merged with the wall of the cylinder. The radial dimension of the packing assembly is consistent with the inner diameter of the extraction tower. A plurality of through holes are arranged on the wall of the cylinder, which penetrate the wall and are connected to the flow channel in the three-dimensional mesh packing body. The fluid can enter and exit the packing through these through holes to ensure smooth flow of the fluid. The packing body is composed of a plurality of packing monomers arranged and combined. Adjacent packing monomers are connected to each other by aligning the side regular quadrilaterals, the side regular hexagons or the upper and lower regular hexagons. The upper and lower adjacent packing monomers are not connected because the top regular hexagon of the packing monomer located below is closed, and the remaining adjacent packing monomers are connected to each other through the flow channel, which is arranged in a high and low staggered manner.

[0032] The obtained packing components are as follows Figure 2 , 3 As shown, it includes an internal cylindrical filler body 1 and a cylindrical outer wall 3 surrounding the filler body 1, and a plurality of through holes are provided on the outer wall 3. The top and bottom of the filler body 1 are provided with reinforcing ribs 3 for improving the anti-punching and deformation capabilities of the filler body. Specifically, the thickness of the outer wall 3 is 1 mm, the thickness of the reinforcing ribs is 2 mm, and the vertical stretching distance along the upper and lower surfaces of the filler body 1 is 2 mm.

[0033] The packing assembly of this embodiment is suitable for high density difference liquid-liquid two-phase extraction process. There are two kinds of fluid channels in the packing, namely regular quadrilateral and regular hexagon, and the flow channels of adjacent packing monomers are connected, so that the liquid phase flow is smoother and the flow resistance of the liquid phase flow is reduced, thus having the advantages of high flux and low pressure drop; the horizontal separation of the packing monomers causes the heavy liquid phase flow to be resisted, which plays a buffering role, increases the contact time of the two phases, and strengthens the mass transfer effect.

[0034] The water-tetrabromoethane two-phase high density difference extraction process was implemented, and the density ratio of water to tetrabromoethane was 1:3. Using the packing assembly of this embodiment, the tetrabromoethane phase was added from the upper part of the packing, and the water phase was added from the lower part of the packing. The flow rate of the tetrabromoethane phase was 1 liter / (hour·cm 2 ), the flow rate of the water phase is 1 L / (h·cm 2 ), tetrabromoethane phase is the dispersed phase, water phase is the continuous phase, and the two phases are fully in contact after passing through the filler. The relevant liquid-liquid dispersion parameters are listed in Table 1.

[0035] Table 1 Key liquid-liquid dispersion data of the filler components of the embodiment under the water-tetrabromoethane extraction system

[0036]

[0037] Comparative Example 1

[0038] This comparative example uses the commonly used ball ring random packing in industry, wherein the packing method and related parameters of the ball ring packing are listed in Table 2. For the water-tetrabromoethane extraction system given in the above embodiment, under the same flow rate and feeding method conditions, the liquid-liquid dispersion related data are listed in Table 3.

[0039] Table 2 Ball ring packing geometric characteristics data

[0040]

[0041] Table 3 Key liquid-liquid dispersion data of ball ring random packing in water-tetrabromoethane extraction system

[0042]

[0043] Compared with the above examples, the flow rate of the dispersed phase in Comparative Example 1 is faster and the content is lower. Although the size of the dispersed droplets is reduced, the contact area between the two phases is greatly reduced. The comparison shows that the packing configuration given in the example is a better extraction packing.

[0044] Comparative Example 2

[0045] This comparative example uses horizontal corrugated plate structured packing commonly used in industry, and the structural dimensions of the packing are listed in Table 4. For the water-tetrabromoethane extraction system given in the above example, under the same flow rate and feeding method, the liquid-liquid dispersion data are listed in Table 5.

[0046] Table 4 Geometric characteristics of horizontal corrugated plate structured packing

[0047] Peak height mm Peak width mm Plate thickness (mm) Corrugation top angle Small hole diameter mm Opening rate 6 12 1 90° 1.2 10.10％

[0048] Table 5 Key liquid-liquid dispersion data of horizontal corrugated plate structured packing in water-tetrabromoethane extraction system

[0049]

[0050] Compared with the above embodiment, the flow rate of the dispersed phase in Comparative Example 2 is faster, the content is lower, and the size of the dispersed droplets is larger, and the contact area between the two phases is reduced more. The comparison shows that the filler configuration given in the embodiment is a better extraction filler.

[0051] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. Application of a packing component in a liquid-liquid extraction system, characterized in that: The packing component includes a packing body with a three-dimensional mesh structure, and the packing body is composed of a plurality of packing monomers arranged and combined; the packing monomer is a hollow truncated regular octahedron structure, formed by 8 regular hexagons and 6 regular quadrilaterals, wherein the upper and lower two regular hexagons are closed planes, and the 6 regular quadrilaterals and 6 regular hexagons on the side have openings to form twelve flow channels; adjacent packing monomers are connected to each other by aligning the side regular quadrilaterals, the side regular hexagons or the upper and lower regular hexagons, wherein the upper and lower adjacent packing monomers are not connected due to the closed regular hexagon on the top of the packing monomer located below, and the remaining adjacent packing monomers are connected to each other through the flow channels, and are arranged in a high and low manner.

2. The use according to claim 1, characterized in that: The bottom of the filler monomer has a regular hexagonal opening.

3. The use according to claim 1, characterized in that: The twelve flow channels are evenly distributed along different side directions, and the cross sections of the flow channels are regular hexagons or regular quadrilaterals respectively.

4. The use according to claim 1, characterized in that: The packing body is cylindrical.

5. The use according to claim 1, characterized in that: The top and bottom of the filler body are provided with reinforcing ribs for improving the anti-punching and deformation capabilities of the filler body.

6. The use according to any one of claims 1 to 5, characterized in that: The filler assembly further comprises an outer wall which surrounds the filler body on the side, and the outer wall is provided with a plurality of through holes which are connected with the flow channel of the filler body.

7. The use according to claim 1, characterized in that: The density difference between the two phases in the liquid-liquid extraction system is not less than 200 kg / m 3 .

8. The use according to claim 1 or 7, characterized in that: The packing assembly has a plane size consistent with that of the extraction tower, and is installed in the extraction tower in a single or multi-layer manner and fits tightly with the inner wall of the extraction tower; The height of the packing assembly is 50 to 1000 mm.

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