A spray-type extraction tower and extraction method

Abstract

The application provides a spray type extraction tower and an extraction method, and belongs to the technical field of chemical equipment. The spray type extraction tower comprises an extraction tower body, a heavy liquid dispersion structure, an inner member and a light liquid dispersion structure which are sequentially arranged from top to bottom in the extraction tower body, the inner member separates a large extraction body inner cavity into multiple small extraction spaces, and the proportion of the cross-sectional area of the small extraction space to the cross-sectional area of the extraction tower body inner cavity is 1:20-200; meanwhile, the heavy liquid dispersion structure and the light liquid dispersion structure are arranged above and below the inner member respectively, so that the corresponding material flow of each small extraction space is stable, the proportion of the heavy liquid phase and the light liquid phase is matched, the radial back mixing in the tower is eliminated, the mass transfer is better, a better extraction and separation effect can be achieved, and the quality of subsequent products is improved.

Description

Technical Field

[0001] This invention belongs to the field of chemical equipment technology, specifically relating to a spray-type extraction tower and extraction method. Background Technology

[0002] Liquid-liquid extraction is an important method for chemical separation, utilizing the different distribution ratios of various substances between two immiscible or partially miscible solvents to achieve the separation or purification of components. The extraction column is one of the main pieces of equipment for realizing the liquid-liquid extraction process, and its main advantage is that it enables large-scale continuous production.

[0003] The epichlorohydrin unit, taking into account both energy consumption and separation efficiency, employs two extraction towers (an extraction tower and a water washing tower) to separate the epichlorohydrin-chloropropylene system and the methanol-water system. Currently, the unit uses a conventional spray-type extraction tower without any internal components. At small scales, the extraction effect is good with no backmixing. However, if the equipment is scaled up directly according to the scale factor during industrialization, backmixing will occur within the extraction tower during operation, affecting the extraction efficiency. Summary of the Invention

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

[0005] This invention is achieved through the following technical solution:

[0006] In a first aspect, 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 arranged sequentially from top to bottom within the extraction tower body;

[0007] The internal components divide the cavity of the extraction tower body into multiple small extraction spaces.

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

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

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

[0011] The internal components include a support frame fixed to the inner wall of the extraction tower body, and multiple insert plates are detachably provided on the support frame;

[0012] Multiple baffles divide the cavity of the extraction tower body into multiple small extraction spaces.

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

[0014] The support frame includes multiple partitions, which are arranged in a crisscrossing manner to form multiple small compartments;

[0015] Each partition plate is provided with an upward-facing groove, into which the insert plate is inserted to achieve a detachable connection between the support frame and the insert plate.

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

[0017] The insert plates are vertical insert plates, and multiple vertical insert 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 insert 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 insert plate is matched with 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 that:

[0021] A connector is provided at the center of four intersecting insert plates. The connector includes a connector body with four outward-facing vertical slots. One sidewall of each of the four insert plates is inserted into one of 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 that:

[0024] The upper side wall of the extraction tower body is provided with a heavy liquid inlet, which is connected to the heavy liquid dispersion structure.

[0025] A light liquid inlet is provided on the lower part of the side wall of the extraction tower body, and the light liquid inlet is connected to the light liquid dispersion structure.

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

[0027] The heavy liquid dispersion structure includes a main heavy liquid pipe, on which multiple heavy liquid branch pipes are provided. Multiple heavy liquid dispersers are fixedly connected to the lower end of the heavy liquid branch pipes. The position and number of the multiple heavy liquid dispersers are the same as the position and number 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 that:

[0029] The light liquid dispersion structure includes a light liquid main pipe, on which multiple light liquid branch pipes are provided. Multiple light liquid dispersers are fixedly connected to the upper end of the light liquid branch pipes. The position and number of the multiple light liquid dispersers are the same as the position and number of each small extraction space, so that there is a one-to-one correspondence between the light liquid dispersers and the small extraction spaces.

[0030] In a second aspect, the present invention provides a spray extraction method, wherein liquid-liquid extraction is performed using a spray extraction tower as described above.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] This invention utilizes internal components within the extraction tower to divide a large extraction tower cavity into multiple smaller extraction spaces. Furthermore, by incorporating heavy liquid dispersion structures above and light liquid dispersion structures below these internal components, both heavy and light liquids are uniformly dispersed within each smaller extraction space. This ensures a stable flow rate in each smaller extraction space, a matched ratio of heavy to light liquid phases, eliminates radial backmixing within the tower, improves mass transfer, achieves better extraction and separation, and enhances the quality of subsequent products. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a spray extraction tower provided in an embodiment of the present invention;

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

[0035] Figure 3 This is a structural schematic diagram of the connector;

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

[0037] Figure 5 It is a diagram showing the correspondence between the dispersed structure and the small extraction space;

[0038] Figure 6 This is a process diagram of the extraction section of an epichlorohydrin unit.

[0039] In the diagram, 1 is the extraction tower body, 2 is the heavy liquid dispersion structure, 3 is the heavy liquid inlet, 4 is the internal components, 5 is the light liquid dispersion structure, 6 is the light liquid inlet, 7 is the light liquid outlet, 8 is the heavy liquid outlet, and 9 is the support frame. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to 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, and a heavy liquid dispersion structure 2, an internal component 4 and a light liquid dispersion structure 5 arranged sequentially from top to bottom inside the extraction tower body 1.

[0043] This invention utilizes an internal component 4 within the extraction tower body 1 to divide a large extraction tower body cavity into multiple small extraction spaces. The ratio of the cross-sectional area of ​​the small extraction space to the cross-sectional area of ​​the extraction tower body cavity is 1:20 to 200, preferably 1:60 to 150. Simultaneously, by providing a heavy liquid dispersion structure 2 and a light liquid dispersion structure 5 above and below the internal component 4 respectively, both heavy and light liquids are uniformly dispersed within each small extraction space. This ensures a stable flow rate for each small extraction space, a matched ratio of heavy to light liquid phases, elimination of radial backmixing within the tower, better mass transfer, improved extraction and separation effects, and enhanced quality of subsequent products.

[0044] Taking epichlorohydrin preparation as an example, the main media of the extraction system are epichlorohydrin, allyl chloride, methanol, and water. The dispersed phase in the extraction tower is allyl chloride, and the continuous phase is the process material. Similarly, the dispersed phase in the water washing tower is water, and the continuous phase is the process material. In this media system, the optimal cross-sectional area of ​​the minimum extraction space is 450mm×450mm to 1000mm×1000mm. A space that is too small is inconvenient for operation and results in too many partitions and a complex structure; a space that is too large will cause backmixing, affecting the extraction effect. Taking a 50,000-ton epichlorohydrin unit as an example, the ratio between the cross-sectional area of ​​the small extraction space and the cross-sectional area of ​​the extraction tower body is between 1:20 and 200, with a preferred range of 1:60 to 150. This helps eliminate backmixing within the tower and improves 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. The support frame 9 is detachably provided with multiple insert plates. The multiple insert plates divide the large extraction space of the extraction tower body 1 into multiple small extraction spaces. The insert plates are detachably mounted on the support frame 9, which facilitates the removal and replacement of the insert plates and subsequent maintenance work.

[0047] like Figure 2 As shown, the support frame 9 includes multiple partition plates, which are arranged in a crisscross pattern to form multiple small compartments; each partition plate is provided with an upward-facing groove, into which an insert plate is inserted to achieve a detachable connection between the support frame and the insert plate.

[0048]

Example 3

[0049] The insert plate is a vertical insert plate, and multiple vertical insert 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 insert plate is selected as needed, the width of each vertical insert 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 insert plate matches the width of the grooves on the four sides of the small compartment on the support frame 9. This can effectively fix the vertical insert plate in the groove, and it is not easy to loosen or even fall off when there is material flow.

[0050] As a further preferred embodiment, a connector is provided in the middle of the four intersecting inserts, such as... Figure 3 As shown, the connector includes a connector body with four outward-facing vertical slots. One side wall of each of the four insert plates is inserted into one of the four vertical slots, which helps to further secure the insert plates and makes them less likely 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. The heavy liquid inlet 3 is connected to the heavy liquid dispersion structure 2. The heavy liquid dispersion structure 2 is used to uniformly 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. The light liquid inlet 6 is connected to the light liquid dispersion structure 5. The light liquid dispersion structure 6 is used to uniformly disperse the light liquid phase in each small extraction space to ensure that the flow rate of each small extraction space is stable, the ratio of heavy liquid phase to light liquid phase is matched, and backmixing is minimized.

[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 main heavy liquid pipe with multiple heavy liquid branch pipes. The central axes of the multiple heavy liquid branch pipes are parallel to each other. Multiple heavy liquid dispersers are fixedly connected to the lower ends of the heavy liquid branch pipes. The positions and number of the multiple heavy liquid dispersers are the same as the positions and number of each extraction space, ensuring a one-to-one correspondence between the heavy liquid dispersers and the small extraction spaces. Figure 5 As shown, this ensures that the flow rate of each small extraction space is stable, the ratio of heavy liquid phase to light liquid phase is matched, and backmixing is minimized.

[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 main light liquid pipe with multiple light liquid branch pipes. The central axes of the multiple light liquid branch pipes are parallel to each other. Multiple light liquid dispersers are fixedly connected to the upper ends of the light liquid branch pipes. The position and number of the multiple light liquid dispersers are the same as the position and number of each small extraction space, so that the light liquid dispersers correspond one-to-one with the small extraction spaces. This ensures that the flow rate of the material corresponding to each small extraction space is stable, the ratio of heavy liquid phase to light liquid phase is matched, and backmixing is minimized.

[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 for liquid-liquid extraction.

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

[0064] This invention utilizes an internal component 4 within the extraction tower body 1 to divide a large extraction tower body cavity into multiple small extraction spaces. The ratio of the cross-sectional area of ​​the small extraction space to the cross-sectional area of ​​the extraction tower body cavity is 1:20 to 200, preferably 1:60 to 150. Simultaneously, by providing a heavy liquid dispersion structure 2 and a light liquid dispersion structure 5 above and below the internal component 4 respectively, both heavy and light liquids are uniformly dispersed within each small extraction space. This ensures a stable flow rate for each small extraction space, a matched ratio of heavy to light liquid phases, elimination of radial backmixing within the tower, better mass transfer, improved extraction and separation effects, and enhanced quality of subsequent products.

[0065] The internal component 4 includes a support frame 9 fixed to the inner wall of the extraction tower body. Multiple insert plates are detachably mounted on the support frame 9, dividing the large extraction space of the extraction tower body 1 into multiple smaller extraction spaces. The detachable mounting of the insert plates on the support frame 9 facilitates disassembly, replacement, and subsequent maintenance. The support frame 9 includes multiple partition plates arranged in a crisscross pattern to form multiple small compartments. Each partition plate has an upward-facing groove, into which an insert plate is inserted to achieve a detachable connection between the support frame and the insert plate.

[0066] The heavy liquid dispersion structure 2 includes a main heavy liquid pipe with multiple branch pipes. The central axes of the branch pipes are parallel to each other. Multiple heavy liquid dispersers are fixedly connected to the lower ends of the branch pipes. The positions and number of the heavy liquid dispersers correspond to the positions and number of each extraction space, ensuring a one-to-one correspondence between the heavy liquid dispersers and the small extraction spaces. Figure 5 As shown, this ensures that the flow rate of each small extraction space is stable, the ratio of heavy liquid phase to light liquid phase is matched, and backmixing is minimized.

[0067] The light liquid dispersion structure 5 includes a main light liquid pipe with multiple light liquid branch pipes. The central axes of the multiple light liquid branch pipes are parallel to each other. Multiple light liquid dispersers are fixedly connected to the upper ends of the light liquid branch pipes. The position and number of the multiple light liquid dispersers are the same as the position and number of each small extraction space, so that the light liquid dispersers correspond one-to-one with the small extraction spaces. This ensures that the flow rate of the material corresponding to each small extraction space is stable, the ratio of heavy liquid phase to light liquid phase is matched, and backmixing is minimized.

[0068] The specific extraction process is as follows:

[0069] Taking an 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 a heavy liquid), and the continuous phase is the process material (process material is used as a light liquid). The light liquid process material flows continuously into the light liquid dispersion structure 5 through the light liquid inlet 6. After being uniformly dispersed by the light liquid dispersion structure 5, it enters each small extraction space and flows continuously upward. At the same time, the heavy liquid allyl chloride enters the heavy liquid dispersion structure 2 through the heavy liquid inlet 3. After being uniformly dispersed by the heavy liquid dispersion structure 2, it enters each small extraction space and flows downward. The process material and allyl chloride come into countercurrent contact in the small extraction spaces to carry out mass transfer.

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

[0072] The beneficial effects of the present invention are further illustrated below through specific embodiments.

[0073]

Example 8

[0074] Taking the preparation of epichlorohydrin as an example, such as Figure 6As shown, the main media of the extraction system are epichlorohydrin, allyl chloride, methanol, and water. The dispersed phase in the extraction tower is allyl chloride, and the continuous phase is the process material. The dispersed phase in the water washing tower is water, and the continuous phase is the process material. Both the extraction tower and the water washing tower utilize the spray-type extraction tower of this invention. Figure 6 In the code, A, B, C, D, E, F, and G represent the serial number.

[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 composition of the top and bottom feeds from the extraction and washing towers were analyzed separately, and the results are detailed in Tables 1 and 2.

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

[0078]

[0079] Table 2. Composition Analysis of the Top and Bottom of the Water Washing Tower

[0080]

[0081] Compositional analysis shows that when the process material, composed of water, methanol, allyl chloride, and epichlorohydrin, enters the extraction tower, the epichlorohydrin and allyl chloride are almost entirely extracted by allyl chloride and discharged from the bottom of the extraction tower, then sent to a water washing tower. Further extraction with water removes the small amounts of light liquid (methanol and water). Allyl chloride and epichlorohydrin are obtained at the top of the water washing tower, while water and methanol are obtained at the bottom. Simultaneously, water and methanol containing small amounts of heavy liquid (allyl chloride and epichlorohydrin) are obtained at the top of the extraction tower. It can be seen that the allyl chloride / epoxychlorohydrin system and the water / methanol system can be essentially completely separated after extraction, with good extraction efficiency and no backmixing.

[0082] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0083] In the description of this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

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

Claims

1. A spray extraction column characterized in that, The extraction tower body is sequentially provided with a heavy liquid dispersion structure, an inner member and a light liquid dispersion structure from top to bottom; the inner member separates the 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 cavity of the extraction tower body is 1:20-200; The inner member comprises a support frame fixed on the inner wall of the extraction tower body, and a plurality of insertion plates are detachably arranged on the support frame; the plurality of insertion plates separate the cavity of the extraction tower body into a plurality of small extraction spaces; the support frame comprises a plurality of partition plates, and the plurality of partition plates are arranged in a cross manner to form a plurality of small compartments; each partition plate is provided with a groove with an opening upward, and the insertion plate is inserted into the groove to achieve detachable connection of the support frame and the insertion plate; the insertion plate is a vertical insertion plate, and a plurality of vertical insertion plates are respectively inserted into the grooves on four edges of each small compartment of the support frame; a connecting piece is arranged at the middle of the four insertion plates arranged in a cross manner, and the connecting piece comprises a connecting piece body, and four vertical clamping grooves with outward openings are arranged on the connecting piece body, and the side walls of the four insertion plates are respectively inserted into the four vertical clamping grooves.

2. The spray extraction column 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 cavity of the extraction tower body is 1:60-150.

3. The spray extraction column according to claim 1, wherein The width of each vertical insertion plate is matched with the length of the groove on the four edges of the small compartment of the support frame; and / or The thickness of each vertical insertion plate is matched with the width of the groove on the four edges of the small compartment of the support frame.

4. The spray extraction column according to claim 3, characterized in that The axis of the vertical clamping groove is parallel to the central axis of the extraction tower body.

5. The spray extraction column of claim 1 wherein, A heavy liquid inlet is arranged on the upper part of the side wall of the extraction tower body, and the heavy liquid inlet is in communication with the heavy liquid dispersion structure; A light liquid inlet is arranged on the lower part of the side wall of the extraction tower body, and the light liquid inlet is in communication with the light liquid dispersion structure.

6. The spray extraction column according to claim 1 or 5, characterized in that The heavy liquid dispersion structure comprises a heavy liquid main pipe, a plurality of heavy liquid branch pipes are arranged on the heavy liquid main pipe, a plurality of heavy liquid dispersers are fixedly connected to the lower end of the heavy liquid branch pipes, the positions and numbers of the plurality of heavy liquid dispersers are the same as those of each extraction space, so that the heavy liquid dispersers correspond to the small extraction spaces one by one.

7. The spray extraction column according to claim 1 or 5, characterized in that The light liquid dispersion structure comprises a light liquid main pipe, a plurality of light liquid branch pipes are arranged on the light liquid main pipe, a plurality of light liquid dispersers are fixedly connected to the upper end of the light liquid branch pipes, the positions and numbers of the plurality of light liquid dispersers are the same as those of each small extraction space, so that the light liquid dispersers correspond to the small extraction spaces one by one.

8. A spray extraction process characterized by, The spray type extraction tower is used for liquid-liquid extraction.

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