CN111569817A - A kind of packing monomer, packing component and its application in liquid-liquid extraction system - Google Patents

Abstract

The invention discloses a filler monomer which is a hollow truncated octahedral structure and is formed by surrounding 8 regular hexagons and 6 regular quadrilaterals, wherein the upper and lower 2 regular hexagons are closed planes, and twelve flow channels are formed by opening holes in the 6 regular tetragons and the 6 regular hexagons on the side surface. The invention also discloses a filler assembly which comprises a filler main body with a three-dimensional net structure, wherein the filler main body is formed by arranging and combining a plurality of filler monomers, the adjacent filler monomers are mutually connected by aligning a side surface regular quadrangle, a side surface regular hexagon or an upper regular hexagon and a lower regular hexagon, the upper and lower adjacent filler monomers are not communicated because the top regular hexagon of the filler monomer positioned below is closed, and the other adjacent filler monomers are mutually communicated through a flow channel and are arranged in a staggered manner. The invention also provides the application of the packing component in a liquid-liquid extraction system.

Description

A kind of packing monomer, packing component and its application in liquid-liquid extraction system

technical field

The invention relates to the technical field of chemical separation, in particular to a filler monomer, a filler component and its application in a liquid-liquid extraction system.

Background technique

Packed column is an important liquid-liquid extraction equipment, which has the characteristics of simple structure, convenient installation and high separation efficiency. The packed tower is mainly composed of packing, tower internals and cylinder, which work together to achieve the effect of mass transfer and separation. Among them, the packing is the core component in the tower, and 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.

The random packing is stacked irregularly in the tower, the liquid-liquid contact is relatively sufficient, and the mass transfer effect of the packing is good. . For the high density difference extraction system, the stepped ring is a commonly used random packing configuration. Due to the directional effect of the flanging structure, the orientation of the packing arrangement is improved, the movement of the fluid in the packing is more regular, and the resistance is reduced. The flux increases and the mass transfer efficiency increases. Patent CN891091512.1 discloses a flat ring packing with a unique inward curved rib structure, which cancels the flanging of the stepped ring, makes the dispersed phase distribution in the tower more uniform, and promotes the dispersion of the dispersed phase droplets in the packing. Merge-break. Patent CN210229985U discloses a high-efficiency reinforced rectangular 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 an inwardly curved rib-shaped flat ring packing with a reinforced zigzag window, which overcomes the problem of serious axial backmixing in the liquid-liquid extraction system.

Compared with random packing, structured packing presents regular geometric arrangement, strong periodicity of fluid motion, lower pressure drop and larger mass transfer area. Typical structured packing includes: 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-merger-redispersion of the liquid phase and ensure the continuous renewal of the mass transfer surface, thereby obtaining high efficiency and great communication. quantity. Patent CN110449113A proposes a high-efficiency structured packing composed of staggered oblique edge packing and straight edge packing. The two-phase flow channel between two adjacent packing layers is smoother, the flow resistance is reduced, the wetting area of the packing is increased, and the contact between the two phases is improved. Fully and effectively increase the specific surface area of the filler. Patent CN210078931U proposes a wavy curved surface diversion structured packing, the channel wall is a wavy curved surface, and the packing units of each layer are placed crosswise with the adjacent layers, which improves the ability of the packing to prevent clogging. Patent CN200610053562.8 discloses a corrugated corrugated packing. The packing is formed by stacking multiple layers of corrugated corrugated corrugated corrugated corrugated corrugations. Every two layers of corrugated corrugated corrugated corrugated packing layers are axially guided. layer, effectively improve the two-phase flow characteristics and improve the interphase mixing effect.

The extraction packed column utilizes two-phase density difference or gravity difference to achieve countercurrent flow and mass transfer, and the existing packing configuration is mainly aimed at the case where the two-phase density difference is small (<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, the disperse phase is difficult to be highly dispersed, and the mass transfer performance becomes poor. Therefore, it is necessary to design a new configuration packing suitable for high-density differential liquid-liquid extraction separation system to ensure efficient dispersion of the dispersed phase in the packing and sufficient contact between the two phases.

SUMMARY OF THE INVENTION

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 are especially suitable for a liquid-liquid two-phase extraction system, which can ensure the efficient dispersion of the dispersed phase and the liquid-liquid two-phase extraction system. The phases are fully contacted, reducing short-circuit and channeling and other undesirable conditions, and effectively increasing the extraction and mass transfer efficiency.

A filler monomer is a hollow truncated regular octahedron structure surrounded by 8 regular hexagons and 6 regular quadrilaterals, of which the upper and lower 2 regular hexagons are closed planes, and the 6 regular quadrilaterals and 6 regular hexagons on the side 12 regular hexagonal openings form twelve flow channels.

The bottom regular hexagon of the packing monomer can also have holes. When the packing monomers are stacked to form the packing assembly, the sealing regular hexagonal plane at the top of the lower packing monomer can be used to separate the upper and lower packing monomers.

Preferably, the twelve flow channels are uniformly distributed along different lateral directions, and the cross-sections of the flow channels are respectively regular hexagons or regular quadrilaterals.

The present invention also provides a filler assembly, comprising a filler body with a three-dimensional network structure, the filler body is formed by arranging and combining a plurality of the filler monomers, and the adjacent filler monomers are aligned by aligning the regular quadrilateral on the side and the regular hexagon on the side. Hexagons or upper and lower regular hexagons are connected to each other, in which the upper and lower adjacent filler monomers are not connected due to the closure of the regular hexagon at the top of the filler monomer located below, and the remaining adjacent filler monomers are connected to each other through the flow channel, showing a high and low level. staggered arrangement.

The filler monomers are arrayed along three orthogonal directions to form a filler body with a three-dimensional network structure with regular fluid channels. Between the adjacent basic unit bodies, the dividing surfaces are opposite to the dividing surfaces, the holes are opposite to the holes, and the flow channels are connected to the flow channels.

Due to the particularity of its structure, the packing assembly can achieve the following two technical effects: 1. The packing monomers of the truncated regular octahedron structure can be tightly packed and completely fill the three-dimensional space to form a three-dimensional frame, avoiding space waste and ensuring good dispersion of the dispersed phase. 2. There is a horizontal separation plate (regular hexagonal closed plane at the top of the filler monomer) in the filler component to increase the residence time of the dispersed phase. The horizontal separation structure in the filler monomer can effectively reduce the falling speed of the heavy dispersed phase and improve the contact between the two phases. area, preventing short circuits and channeling, and enhancing two-phase mass transfer extraction.

Preferably, the filler body is cylindrical.

Preferably, the top and bottom of the packing body are provided with reinforcing ribs for improving the stamping and deformation resistance of the packing body.

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 communicating with the flow channels 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 channels 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 invention also provides the application of the packing assembly in the liquid-liquid extraction system.

During the extraction process, the fluid flows in the packing, and the packing has channels that satisfy the distribution and movement of the fluid. In the new configuration packing proposed by the present invention, the distribution of flow channels is as follows: firstly, the regular quadrilateral area openings in each wrapping surface of the basic unit body (filler monomer) are set as fluid channels (flow channels); secondly, the six regular hexagons on the side The polygonal plane also has holes (preferably, regular hexagonal holes are opened in the center of the plane) to form flow channels, and the twelve flow channels are evenly distributed along different lateral directions; Twelve flow channels are connected with adjacent basic units, and each connected basic unit is arranged in a staggered arrangement.

In the packing assembly, the upper and lower surfaces of the basic unit body (wherein the lower surface may be the top surface of the lower basic unit body connected to it) are in a closed state, and during the extraction process, the liquid phase is in the filler monomer It is divided into multiple liquid phases and enter into different channels respectively. The upper and lower horizontal baffles of the basic unit act as fluid barriers, reduce the vertical movement of the fluid, strengthen the fluid baffle and dispersion, increase the contact time of the two phases, and improve the mass transfer efficiency. .

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

Preferably, the plane size of the packing assembly is the same as that of the extraction column, and is installed in the extraction column in a single or multiple layers. Packing components are used in a layer-by-layer manner, which can meet the requirements of any separation height and theoretical separation stages.

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

Compared with the prior art, the main advantages of the present invention include: the hollow truncated regular octahedron structure is selected as the basic unit body, which can effectively fill the three-dimensional space, and the heavy dispersed phase enters the high-density differential liquid-liquid extraction structured packing from top to bottom, With the flow of the heavy dispersed phase, it enters the filler monomer through the channel and is cut into multiple liquid flows in different directions, resulting in a good dispersion of the dispersed phase in space and improving the uniformity of liquid flow distribution in the filler; the horizontal separation structure acts as a buffer The action of the heavy dispersed phase leads to the aggregation of the dispersed phase in the packing unit, the falling speed is slowed down, the contact time of the two phases is increased, the retention and dispersion are increased, and the mass transfer efficiency is improved.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of the filler monomer of the embodiment;

2 is a schematic three-dimensional structure diagram of the packing assembly of the embodiment;

FIG. 3 is a partially enlarged structural schematic diagram of the packing assembly of the embodiment;

FIG. 4 is a schematic flow chart of the filler monomer structure of the embodiment of the filler assembly;

In the figure: 11-regular hexagonal closed plane, 12-regular quadrilateral fluid channel, 13-regular hexagonal fluid channel, 14-packing monomer side filler, 1-packing main body, 2-reinforcing rib, 3-outer wall.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. The operation method without specifying the specific conditions in the following examples is usually in accordance with the conventional conditions, or in accordance with the conditions suggested by the manufacturer.

Example

As shown in FIG. 1 , 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 (Horizontal separation structure of filler monomers), 6 regular quadrilateral and 6 regular hexagonal openings on the side form twelve flow channels, which are 6 regular quadrilateral fluid passages 12 and 6 regular hexagonal fluid passages 13 respectively. Twelve flow channels are evenly distributed along different lateral directions. Specifically, the thickness of the side wall of the filler monomer is 0.5mm, the regular hexagonal closed plane 11, the regular quadrilateral fluid channel 12, and the edge length R of the side filler 14 are all equal to 4mm; A regular hexagonal hole is opened in the center, and the length L of the opening edge is 2.8mm.

The process of assembling the above-mentioned packing monomers to form a packing assembly is shown in Figure 4. A plurality of packing monomers are combined and arranged in an array along three orthogonal directions, so as to be suitable for a cylindrical extraction tower. The obtained cuboid configuration is obtained by cutting, pulling A cylindrical packing body with a three-dimensional network structure with regular fluid channels is extended, and then the cylindrical outer wall is surrounded on the side of the cylindrical packing body and merged with the cylindrical wall. The radial dimension of the packing assembly is consistent with the inner diameter of the extraction tower. The wall surface of the cylinder is provided with a plurality of through holes, which penetrate the wall surface and are connected with the flow channels 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 filler main body is composed of several filler monomers arranged and combined, and the adjacent filler monomers are connected to each other by aligning side regular quadrilaterals, side regular hexagons or upper and lower regular hexagons, wherein the upper and lower adjacent filler monomers are located at the bottom due to the The regular hexagon at the top of the filler monomer is closed and not connected, and the other adjacent filler monomers are connected with each other through the flow channel, and are arranged in a staggered arrangement.

The obtained packing assembly, as shown in Figures 2 and 3, includes an inner cylindrical packing body 1 and a cylindrical outer wall 3 surrounding the packing body 1, and the outer wall 3 is provided with a plurality of through holes. The top and bottom of the packing body 1 are provided with reinforcing ribs 3 for improving the stamping and deformation resistance of the packing body. Specifically, the thickness of the outer wall 3 is 1 mm, the thickness of the reinforcing rib is 2 mm, and the vertical stretching distance along the upper and lower surfaces of the filler body 1 is 2 mm.

The packing assembly of this embodiment is suitable for a high-density differential liquid-liquid two-phase extraction process. There are two kinds of fluid channels in the packing, which are regular quadrilateral and regular hexagon, and the flow channels of adjacent packing monomers are connected, which makes the liquid phase flow more smooth and reduces the flow resistance of liquid phase flow, so it has high flux , low pressure drop and other advantages; the horizontal separation of the filler monomer leads to resistance to the flow of the heavy liquid phase, which acts as a buffer, increases the contact time of the two phases, and strengthens the mass transfer effect.

Taking the water-tetrabromoethane two-phase high density difference extraction process as the implementation object, the density ratio of water and tetrabromoethane is 1:3. Using the packing assembly of this embodiment, the tetrabromoethane phase is added from the upper part of the filler, the water phase is added from the lower part of the filler, the flow rate of the tetrabromoethane phase is 1 liter/(hour·cm ² ), and the flow rate of the water phase is 1 liter/(hour·cm ² ), the tetrabromoethane phase is the dispersed phase, and the water phase is the continuous phase. After passing through the filler, the two phases are fully contacted. The parameters of the relevant liquid-liquid dispersion are listed in Table 1.

Table 1 Under the water-tetrabromoethane extraction system, the key liquid-liquid dispersion data of the packing assembly of the embodiment

Comparative Example 1

This comparative example adopts the Pall ring random packing commonly used in the industry, among which the Pall ring packing filling method and related parameters are listed in Table 2. For the water-tetrabromoethane extraction system given in the above example, under the conditions of the same flow rate and feeding mode, the relevant data of liquid-liquid dispersion are listed in Table 3.

Table 2 Pall ring packing geometric characteristic data

Table 3 Key liquid-liquid dispersion data of Pall ring random packing under water-tetrabromoethane extraction system

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

Comparative Example 2

This comparative example adopts the horizontal corrugated plate structured packing commonly used in the 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 mode, the liquid-liquid dispersion data are listed in Table 5.

Table 4 Geometric characteristic data of horizontal corrugated plate structured packing

Peak height mm Peak width mm Plate thickness mm corrugated top angle Small hole diameter mm F 6 12 1 90° 1.2 10.10%

Table 5 Under the water-tetrabromoethane extraction system, the key liquid-liquid dispersion data of the horizontal corrugated plate structured packing

In Comparative Example 2, compared with the above examples, the flow rate of the dispersed phase is faster, the content is lower, and the size of the dispersed droplets is larger, and the contact area of the two phases decreases more. The comparison shows that the packing configuration given in the example is a better extraction packing.

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

Claims (10)

1. a filler monomer, it is characterized in that, it is a hollow truncated regular octahedron structure, surrounded by 8 regular hexagons and 6 regular quadrilaterals, wherein the upper and lower 2 regular hexagons are closed planes, and the side hexagons are closed. 6 regular quadrilaterals and 6 regular hexagonal openings form twelve flow channels. 2 . The filler monomer according to claim 1 , wherein the bottom is a regular hexagonal opening. 3 . 3 . The filler monomer according to claim 1 , wherein the twelve flow channels are evenly distributed along different lateral directions, and the cross-sections of the flow channels are respectively regular hexagons or regular quadrilaterals. 4 . 4. A filler assembly, characterized in that it comprises a filler body with a three-dimensional network structure, the filler body is formed by arranging and combining a plurality of filler monomers according to any one of claims 1 to 3, adjacent filler monomers Connected to each other by aligning side regular quadrilaterals, side regular hexagons or upper and lower regular hexagons, wherein two adjacent filler monomers are not connected due to the closure of the top regular hexagon of the lower filler monomers, and the remaining adjacent filler monomers are connected to each other. They are connected to each other through the flow channels and are arranged in a staggered arrangement. 5. The packing assembly of claim 4, wherein the packing body is cylindrical. 6 . The packing assembly according to claim 4 , wherein the top and bottom of the packing body are provided with reinforcing ribs for improving the stamping and deformation resistance of the packing body. 7 . 7. The packing assembly according to any one of claims 4 to 6, further comprising an outer wall surrounding the packing body on a side surface, the outer wall is provided with a plurality of channels communicating with the flow channels of the packing body hole. 8. The application of the packing assembly according to any one of claims 4 to 7 in a liquid-liquid extraction system. 9 . The application according to claim 8 , wherein the density difference between the two phases in the liquid-liquid extraction system is not less than 200kg/m ³ . 10. The application according to claim 8 or 9, wherein the packing assembly has the same plane size as that of the extraction column, and is installed in the interior of the extraction column in a single or multiple layers and is closely matched with the inner wall of the extraction column; The height of the packing assembly is 50-1000 mm.

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