Spraying type extraction tower and extraction method

Abstract

The invention provides a spraying type extraction tower and an extraction method, and belongs to the technical field of chemical equipment. The spraying type extraction tower comprises an extraction tower body, a heavy liquid dispersion structure, internal components and a light liquid dispersion structure are sequentially arranged in the extraction tower body from top to bottom, and the internal components divide an inner cavity of the extraction tower body into a plurality of small extraction spaces. The ratio of the cross sectional area of the small extraction space to the cross sectional area of the inner cavity of the extraction tower body is 1: (20-200); meanwhile, a heavy liquid dispersion structure and a light liquid dispersion structure are respectively arranged above and below the inner component, so that the material flow quantity corresponding to each small extraction space is stable, the proportion of a heavy liquid phase and the proportion of a light liquid phase are matched, the radial backmixing in the tower is eliminated, the mass transfer is better, a better extraction separation effect can be achieved, and the quality of subsequent products is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical equipment, and in particular relates to a spray-type extraction tower and an extraction method. Background Art

[0002] Liquid-liquid extraction is one of the important methods of chemical separation, which uses the different distribution ratios of each substance between two immiscible or partially miscible solvents to achieve the separation or purification of each component. The extraction tower is one of the main equipment to achieve the liquid-liquid extraction process, and its main advantage is that it can achieve large-scale continuous production.

[0003] The epichlorohydrin device takes energy consumption and separation effect into consideration and uses two extraction towers (an extraction tower and a water washing tower) to separate epichlorohydrin, allyl chloride system and methanol, water system. The current device uses a conventional spray extraction tower, which does not have any internal components. The extraction effect is good on a small scale and there is no back mixing. However, after industrialization, if the equipment is directly enlarged according to the scale factor, back mixing will occur in the extraction tower during operation, affecting the extraction effect. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problems existing in the prior art and to provide a spray-type extraction tower and an extraction method, which can effectively solve the back-mixing phenomenon in the existing extraction tower and improve the extraction effect.

[0005] The present invention is achieved through the following technical solutions:

[0006] A first aspect of the present invention provides a spray-type extraction tower, comprising an extraction tower body, wherein a heavy liquid dispersion structure, an internal component and a light liquid dispersion structure are sequentially arranged in the extraction tower body from top to bottom;

[0007] The internal component divides the inner cavity of the extraction tower body into a plurality of small extraction spaces.

[0008] A further improvement of the present invention is:

[0009] The ratio of the cross-sectional area of ​​the small extraction space to the cross-sectional area of ​​the inner cavity of the extraction tower body is 1:20-200, preferably in the range of 1:60-150.

[0010] A further improvement of the present invention is:

[0011] The internal component comprises a support frame fixed on the inner wall of the extraction tower body, and a plurality of plug plates are detachably provided on the support frame;

[0012] A plurality of insert plates divide the cavity of the extraction tower body into a plurality of small extraction spaces.

[0013] A further improvement of the present invention is:

[0014] The support frame includes a plurality of partition plates, and the plurality of partition plates are arranged crosswise to form a plurality of small compartments;

[0015] Each partition plate is provided with a groove opening upward, and the plug plate is inserted into the groove to achieve a detachable connection between the support frame and the plug plate.

[0016] A further improvement of the present invention is:

[0017] The plug plates are vertical plug plates, and a plurality of vertical plug plates are respectively inserted into the grooves on the four sides of each small compartment on the support frame; and / or,

[0018] The width of each vertical plug plate matches the length of the grooves on the four sides of the small compartment on the support frame; and / or,

[0019] The thickness of each vertical plug plate matches the width of the grooves on the four sides of the small compartment on the support frame.

[0020] A further improvement of the present invention is:

[0021] A connector is provided in the middle of the four intersecting plug boards, the connector comprising a connector body, the connector body is provided with four vertical slots opening outward, and the side walls of the four plug boards are respectively inserted into the four vertical slots; and / or,

[0022] The axis of the vertical slot is parallel to the central axis of the extraction tower body.

[0023] A further improvement of the present invention is:

[0024] A heavy liquid inlet is provided on the upper part of the side wall of the extraction tower body, and the heavy liquid inlet is connected to the heavy liquid dispersion structure;

[0025] A light liquid inlet is arranged at the lower part of the side wall of the extraction tower body, and the light liquid inlet is communicated with the light liquid dispersion structure.

[0026] A further improvement of the present invention is:

[0027] The heavy liquid dispersion structure includes a heavy liquid main pipe, on which a plurality of heavy liquid branch pipes are arranged, and the lower ends of the heavy liquid branch pipes are fixedly connected to a plurality of heavy liquid dispersers, and the positions and quantities of the plurality of heavy liquid dispersers are the same as the positions and quantities of each extraction space, so that the heavy liquid dispersers correspond one to one with the small extraction spaces.

[0028] A further improvement of the present invention is:

[0029] The light liquid dispersion structure includes a light liquid main pipe, on which a plurality of light liquid branch pipes are arranged, and the upper ends of the light liquid branch pipes are fixedly connected to a plurality of light liquid dispersers, and the positions and quantities of the plurality of light liquid dispersers are the same as the positions and quantities of each small extraction space, so that the light liquid dispersers correspond one to one with the small extraction spaces.

[0030] The second aspect of the present invention provides a spray extraction method, which uses the spray extraction tower as described above to perform liquid-liquid extraction.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention divides a large extraction body inner cavity into a plurality of small extraction spaces by arranging an internal component in the extraction tower body, and at the same time arranges a heavy liquid dispersion structure and a light liquid dispersion structure above and below the internal component respectively, so that the heavy liquid and the light liquid can be evenly dispersed in each small extraction space, so that the material flow rate corresponding to each small extraction space is stable, the ratio of the heavy liquid phase and the light liquid phase is matched, radial backmixing in the tower is eliminated, mass transfer is better, better extraction and separation effect can be achieved, and the quality of subsequent products is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of a spray-type extraction tower provided by an embodiment of the present invention;

[0034] Figure 2 It is a structural schematic diagram of the support frame;

[0035] Figure 3 It is a schematic diagram of the structure of the connecting parts;

[0036] Figure 4 It is a schematic diagram of the heavy liquid dispersion structure;

[0037] Figure 5 It is the corresponding relationship diagram between the dispersed structure and the small extraction space;

[0038] Figure 6 This is the process diagram of the extraction part of the epichlorohydrin unit.

[0039] In the figure, 1. extraction tower body, 2. heavy liquid dispersion structure, 3. heavy liquid inlet, 4. internal components, 5. light liquid dispersion structure, 6. light liquid inlet, 7. light liquid outlet, 8. heavy liquid outlet, 9. support frame. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0041] [Example 1]

[0042] like Figure 1As shown, this embodiment provides a spray-type extraction tower, including an extraction tower body 1, in which a heavy liquid dispersion structure 2, an internal component 4 and a light liquid dispersion structure 5 are sequentially arranged from top to bottom.

[0043] The present invention divides a large extraction tower body inner cavity into a plurality of small extraction spaces by arranging an internal component 4 in an extraction tower body 1, wherein the ratio of the cross-sectional area of ​​the small extraction space to the cross-sectional area of ​​the inner cavity of the extraction tower body is 1:20-200, and the preferred range is 1:60-150; at the same time, by arranging a heavy liquid dispersion structure 2 and a light liquid dispersion structure 5 above and below the internal component 4, respectively, the heavy liquid and the light liquid can be evenly dispersed in each small extraction space, so that the material flow rate corresponding to each small extraction space is stable, the ratio of the heavy liquid phase to the light liquid phase is matched, radial backmixing in the tower is eliminated, mass transfer is better, better extraction and separation effect can be achieved, and the quality of subsequent products is improved.

[0044] Taking the preparation of epichlorohydrin as an example, the main media of the extraction system are epichlorohydrin, allyl chloride, methanol and water. The dispersed phase of the extraction tower is allyl chloride, and the continuous phase is the process material. The dispersed phase of the water washing tower is water, and the continuous phase is the process material. In such a medium system, the cross-sectional area of ​​the minimum extraction space is preferably 450mm×450mm~1000mm×1000mm. If the space is too small, it will be inconvenient to operate, and there will be too many partitions and the structure will be complicated; if the space is too large, there will be back mixing, which will affect the extraction effect. Taking a 50,000-ton epichlorohydrin unit as an example, when the ratio between the cross-sectional area of ​​the small extraction space and the cross-sectional area of ​​the extraction tower body is 1:20~200, and the preferred range is 1:60~150, it will help eliminate the back mixing phenomenon in the tower and improve the extraction effect.

[0045] [Example 2]

[0046] The internal component 4 includes a support frame 9 fixed on the inner wall of the extraction tower body, and a plurality of plug plates are detachably provided on the support frame 9. The plurality of plug plates divide a large extraction space of the extraction tower body 1 into a plurality of small extraction spaces, and the plug plates are detachably arranged on the support frame 9, so as to facilitate the disassembly and replacement of the plug plates and subsequent maintenance work.

[0047] like Figure 2 As shown, the support frame 9 includes a plurality of partition plates, which are cross-arranged to form a plurality of small compartments; each partition plate is provided with a groove opening upward, and the plug plate is inserted into the groove to realize a detachable connection between the support frame and the plug plate.

[0048] [Example 3]

[0049] The plug plates are vertical plug plates, and multiple vertical plug plates are respectively inserted into the grooves on the four sides of each small compartment on the support frame 9. Preferably, the height of each vertical plug plate is selected according to needs, the width of each vertical plug plate matches the length of the grooves on the four sides of the small compartment on the support frame 9, and the thickness of each vertical plug plate matches the width of the grooves on the four sides of the small compartment on the support frame 9. In this way, the vertical plug plates can be well fixed in the grooves and are not easy to loosen or even fall off when there is material flow.

[0050] As a further preferred embodiment, a connecting piece is provided in the middle of the four intersecting plug boards, such as Figure 3 As shown, the connector includes a connector body, on which are disposed four vertical slots opening outward, and one side wall of four plug boards are respectively inserted into the four vertical slots, which helps to further tighten the plug boards so that they are not easy to loosen or even fall off.

[0051] The axis of the vertical slot is parallel to the central axis of the extraction tower body.

[0052] [Example 4]

[0053] like Figure 1 As shown, a heavy liquid inlet 3 is provided on the upper part of the side wall of the extraction tower body 1, and the heavy liquid inlet 3 is connected with the heavy liquid dispersion structure 2, and the heavy liquid dispersion structure 2 is used to evenly disperse the heavy liquid phase in each small extraction space; a light liquid inlet 6 is provided on the lower part of the side wall of the extraction tower body 1, and the light liquid inlet 6 is connected with the light liquid dispersion structure 5, and the light liquid dispersion structure 6 is used to evenly disperse the light liquid phase in each small extraction space, so as to ensure that the material flow rate corresponding to each small extraction space is stable, the ratio of the heavy liquid phase and the light liquid phase is matched, and the back mixing is reduced as much as possible.

[0054] The extraction tower body 1 is provided with a light liquid outlet 7 at the top and a heavy liquid outlet 8 at the bottom.

[0055] [Example 5]

[0056] like Figure 4 As shown, the heavy liquid dispersion structure 2 includes a heavy liquid main pipe, on which a plurality of heavy liquid branch pipes are arranged, the central axes of the plurality of heavy liquid branch pipes are parallel to each other, and the lower ends of the heavy liquid branch pipes are fixedly connected with a plurality of heavy liquid dispersers, and the positions and numbers of the plurality of heavy liquid dispersers are the same as the positions and numbers of each extraction space, so that the heavy liquid dispersers correspond one to one with the small extraction spaces, as shown in FIG. Figure 5 As shown, it is ensured that the material flow rate corresponding to each small extraction space is stable, the ratio of the heavy liquid phase and the light liquid phase is matched, and the back mixing is reduced as much as possible.

[0057] The heavy liquid disperser adopts the structure of a conventional extraction tower distributor, which will not be described in detail here.

[0058] [Example 6]

[0059] The light liquid dispersion structure 5 includes a light liquid main pipe, on which a plurality of light liquid branch pipes are arranged, the central axes of the plurality of light liquid branch pipes are parallel to each other, and the upper ends of the light liquid branch pipes are fixedly connected with a plurality of light liquid dispersers, and the positions and numbers of the plurality of light liquid dispersers are the same as the positions and numbers of each small extraction space, so that the light liquid dispersers correspond one-to-one with the small extraction spaces to ensure that the material flow rate corresponding to each small extraction space is stable, the ratio of the heavy liquid phase to the light liquid phase is matched, and the back mixing is reduced as much as possible.

[0060] The light liquid disperser adopts the structure of a conventional extraction tower distributor, which will not be described in detail here.

[0061] [Example 7]

[0062] This embodiment provides a spray extraction method, which uses a spray extraction tower to perform liquid-liquid extraction.

[0063] like Figure 1 As shown, the spray-type extraction tower comprises an extraction tower body 1, in which a heavy liquid dispersion structure 2, an internal component 4 and a light liquid dispersion structure 5 are sequentially arranged from top to bottom.

[0064] The present invention divides a large extraction tower body inner cavity into a plurality of small extraction spaces by arranging an internal component 4 in an extraction tower body 1, wherein the ratio of the cross-sectional area of ​​the small extraction space to the cross-sectional area of ​​the inner cavity of the extraction tower body is 1:20-200, and the preferred range is 1:60-150; at the same time, by arranging a heavy liquid dispersion structure 2 and a light liquid dispersion structure 5 above and below the internal component 4, respectively, the heavy liquid and the light liquid can be evenly dispersed in each small extraction space, so that the material flow rate corresponding to each small extraction space is stable, the ratio of the heavy liquid phase to the light liquid phase is matched, radial backmixing in the tower is eliminated, mass transfer is better, better extraction and separation effect can be achieved, and the quality of subsequent products is improved.

[0065] The internal component 4 includes a support frame 9 fixed on the inner wall of the extraction tower body, and a plurality of plug-in plates are detachably provided on the support frame 9. The plurality of plug-in plates divide a large extraction space of the extraction tower body 1 into a plurality of small extraction spaces, and the plug-in plates are detachably provided on the support frame 9, which facilitates the removal and replacement of the plug-in plates, as well as subsequent maintenance work. The support frame 9 includes a plurality of partition plates, which are arranged crosswise to form a plurality of small compartments; each partition plate is provided with a groove opening upward, and the plug-in plate is inserted into the groove to realize the detachable connection between the support frame and the plug-in plate.

[0066] The heavy liquid dispersion structure 2 includes a heavy liquid main pipe, on which a plurality of heavy liquid branch pipes are arranged, the central axes of the plurality of heavy liquid branch pipes are parallel to each other, and the lower ends of the heavy liquid branch pipes are fixedly connected to a plurality of heavy liquid dispersers, and the positions and numbers of the plurality of heavy liquid dispersers are the same as the positions and numbers of each extraction space, so that the heavy liquid dispersers correspond one to one with the small extraction spaces, such as Figure 5 As shown, it is ensured that the material flow rate corresponding to each small extraction space is stable, the ratio of the heavy liquid phase and the light liquid phase is matched, and the back mixing is reduced as much as possible.

[0067] The light liquid dispersion structure 5 includes a light liquid main pipe, on which a plurality of light liquid branch pipes are arranged, the central axes of the plurality of light liquid branch pipes are parallel to each other, and the upper ends of the light liquid branch pipes are fixedly connected with a plurality of light liquid dispersers, and the positions and numbers of the plurality of light liquid dispersers are the same as the positions and numbers of each small extraction space, so that the light liquid dispersers correspond one-to-one with the small extraction spaces to ensure that the material flow rate corresponding to each small extraction space is stable, the ratio of the heavy liquid phase to the light liquid phase is matched, and the back mixing is reduced as much as possible.

[0068] The specific extraction process is:

[0069] Taking the epichlorohydrin unit as an example, the main media of the extraction system are epichlorohydrin, allyl chloride, methanol and water.

[0070] The dispersed phase of the extraction tower is allyl chloride (allyl chloride is used as heavy liquid), and the continuous phase is process material (process material is used as light liquid). The light liquid process material continuously flows into the light liquid dispersion structure 5 from the light liquid inlet 6, enters each small extraction space after being evenly dispersed by the light liquid dispersion structure 5, and continuously flows upward. At the same time, the heavy liquid allyl chloride enters the heavy liquid dispersion structure 2 from the heavy liquid inlet 3, enters each small extraction space after being evenly dispersed by the heavy liquid dispersion structure 2, and flows downward. The process material and allyl chloride are in countercurrent contact in the small extraction space to carry out mass transfer.

[0071] The dispersed phase of the water washing tower is water (water serves as the heavy liquid), and the continuous phase is the process material from the bottom of the extraction tower (the process material serves as the light liquid). The light liquid process material continuously flows into the light liquid dispersion structure 5 from the light liquid inlet 6, and enters each small extraction space after being evenly dispersed by the light liquid dispersion structure 5 and flows upward continuously. At the same time, the heavy liquid water enters the heavy liquid dispersion structure 2 from the heavy liquid inlet 3, and enters each small extraction space after being evenly dispersed by the heavy liquid dispersion structure 2 and flows downward. The process material and water are in countercurrent contact in the small extraction space to carry out mass transfer.

[0072] The beneficial effects of the present invention are further illustrated by means of specific examples below.

[0073] [Example 8]

[0074] Taking the preparation of epichlorohydrin as an example, Figure 6As shown, the main medium of the extraction system is epichlorohydrin, allyl chloride, methanol and water. The dispersed phase of the extraction tower is allyl chloride, and the continuous phase is the process material. The dispersed phase of the water washing tower is water, and the continuous phase is the process material. The extraction tower and the water washing tower are both spray-type extraction towers of the present invention. Figure 6 A, B, C, D, E, F, and G represent the flow stock numbers respectively.

[0075] In this embodiment, the ratio of the cross-sectional area of ​​the small extraction space in the extraction tower and the water washing tower to the cross-sectional area of ​​the inner cavity of the extraction tower body is 1:100.

[0076] The compositions of the top and bottom discharges of the extraction tower and the water washing tower were analyzed respectively. The results are shown in Tables 1 and 2.

[0077] Table 1 Composition analysis of the top and bottom of the extraction tower

[0078]

[0079] Table 2 Analysis of the composition of the top and bottom of the water washing tower

[0080]

[0081] From the composition analysis, it can be seen that after the process materials composed of water, methanol, allyl chloride and epichlorohydrin enter the extraction tower, the epichlorohydrin and allyl chloride therein are basically extracted by allyl chloride, discharged from the bottom of the extraction tower, and sent to the water washing tower, where a small amount of light liquid (methanol, water) contained therein is further extracted by water, and allyl chloride and epichlorohydrin are obtained at the top of the water washing tower, and water and methanol are obtained at the bottom of the water washing tower. At the same time, water and methanol containing a small amount of heavy liquid (allyl chloride, epichlorohydrin) are obtained at the top of the extraction tower. It can be seen that the allyl chloride, epichlorohydrin system and the water, methanol system can be basically completely separated after extraction, and the extraction effect is good without back mixing.

[0082] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0083] In the description of the present invention, unless otherwise specified, the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0084] The above technical solution is only one implementation mode of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the principles disclosed in the present invention, and it is not limited to the technical solution described in the above specific embodiments of the present invention. Therefore, the above description is only preferred and does not have a restrictive meaning.

Claims

1. A spray type extraction tower, characterized in that: The extraction tower body comprises a heavy liquid dispersion structure, an internal component and a light liquid dispersion structure arranged in sequence from top to bottom; The internal component divides the inner cavity of the extraction tower body into a plurality of small extraction spaces.

2. The spray type extraction tower according to claim 1, characterized in that: The ratio of the cross-sectional area of ​​the small extraction space to the cross-sectional area of ​​the inner cavity of the extraction tower body is 1:20-200, preferably 1:60-150.

3. The spray type extraction tower according to claim 1, characterized in that: The internal component comprises a support frame fixed on the inner wall of the extraction tower body, and a plurality of plug plates are detachably provided on the support frame; The plurality of insert plates divide the cavity of the extraction tower body into a plurality of small extraction spaces.

4. The spray type extraction tower according to claim 3, characterized in that: The support frame includes a plurality of partition plates, and the plurality of partition plates are arranged crosswise to form a plurality of small compartments; Each partition plate is provided with a groove opening upward, and the plug plate is inserted into the groove to achieve a detachable connection between the support frame and the plug plate.

5. The spray type extraction tower according to claim 4, characterized in that: The plug board is a vertical plug board, and a plurality of the vertical plug boards are respectively inserted into the grooves on the four sides of each small compartment on the support frame; and / or, The width of each of the vertical plug plates matches the length of the grooves on the four sides of the small compartment on the support frame; and / or, The thickness of each of the vertical insert plates matches the width of the grooves on the four sides of the small compartment on the support frame.

6. The spray type extraction tower according to claim 5, characterized in that: A connector is provided in the middle of the four intersecting plug boards, the connector comprising a connector body, the connector body is provided with four vertical slots opening outward, and the side walls of the four plug boards are respectively inserted into the four vertical slots; and / or, The axis of the vertical slot is parallel to the central axis of the extraction tower body.

7. The spray type extraction tower according to claim 1, characterized in that: A heavy liquid inlet is provided on the upper part of the side wall of the extraction tower body, and the heavy liquid inlet is connected to the heavy liquid dispersion structure; A light liquid inlet is arranged at the lower part of the side wall of the extraction tower body, and the light liquid inlet is communicated with the light liquid dispersion structure.

8. The spray type extraction tower according to claim 1 or 7, characterized in that: The heavy liquid dispersion structure includes a heavy liquid main pipe, on which a plurality of heavy liquid branch pipes are arranged, and the lower ends of the heavy liquid branch pipes are fixedly connected to a plurality of heavy liquid dispersers, and the positions and quantities of the plurality of heavy liquid dispersers are the same as the positions and quantities of each extraction space, so that the heavy liquid dispersers correspond one to one with the small extraction spaces.

9. The spray type extraction tower according to claim 1 or 7, characterized in that: The light liquid dispersion structure includes a light liquid main pipe, on which a plurality of light liquid branch pipes are arranged, and the upper ends of the light liquid branch pipes are fixedly connected to a plurality of light liquid dispersers, and the positions and quantities of the plurality of light liquid dispersers are the same as the positions and quantities of each small extraction space, so that the light liquid dispersers correspond one to one with the small extraction spaces.

10. A spray extraction method, characterized in that: Liquid-liquid extraction is carried out using the spray-type extraction tower as described in any one of claims 1 to 9.

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