A rectification column

Abstract

The utility model provides a rectifying column, rectifying column includes casing, heat exchanger, reflux separation cavity, gas phase export and liquid phase export, reflux separation cavity with heat exchanger sets up in the inside of casing, reflux separation cavity is located heat exchanger below, and reflux separation cavity's top with heat exchanger's bottom is linked together, reflux separation cavity with the casing has the gap to form first fluid channel, reflux separation cavity's bottom is provided with second fluid channel, and second fluid channel is liquid phase channel, gas phase export sets up in reflux separation cavity's upper position, liquid phase export sets up in the bottom of casing, the utility model tower top heat exchanger and reflux separation cavity are built -in in tower top, and are integrated with tower, and the structure is compact, has reduced gas pressure drop loss, and is favorable to the heat transfer and mass transfer of strengthening tower, improves the separation efficiency of tower.

Description

Technical Field

[0001] This utility model relates to the field of distillation technology, and in particular to a distillation column. Background Technology

[0002] In the fields of petrochemicals, coal chemicals, natural gas, and air separation, cryogenic separation methods are often used to obtain high-purity products that meet the requirements. To obtain high-purity products, the gas needs to be condensed and separated, and then purified by heat and mass transfer in a distillation column to purify the mixture containing multiple components. In this process, enhancing heat and mass transfer is crucial to the separation effect.

[0003] Currently, most methods for condensing and separating overhead gas involve external heat exchangers and separators, which are very unfavorable for installation and construction. They also require overcoming significant pipeline pressure drops, which increases the energy consumption of the equipment. Alternatively, the overhead gas flows upward in the condensation channel of the overhead heat exchanger. This technology, in order to ensure that the condensed liquid from the overhead gas is not carried upward by the gas and can flow by gravity to the rectification section of the distillation column, sets the flow area of ​​the condensation channel to be very large, resulting in a very large overhead heat exchanger. However, its heat exchange efficiency is very low, the heat exchange effect is poor, and there is a risk that the condensation design value will not be met, and the equipment investment will also increase exponentially. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a distillation column. By integrating the heat exchanger and reflux separation chamber into the distillation column, the structure has a low pressure reduction, high heat exchange efficiency, and can reduce costs and energy consumption of the equipment. It is also beneficial to enhance the heat and mass transfer of the column and improve the separation efficiency of the column.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] This invention provides a distillation column, comprising a shell, a heat exchanger, a reflux separation chamber, a gas phase outlet, and a liquid phase outlet. The reflux separation chamber and the heat exchanger are disposed inside the shell, with the reflux separation chamber located below the heat exchanger and its top connected to the bottom of the heat exchanger. A gap exists between the reflux separation chamber and the shell to form a first fluid channel. A second fluid channel, which is a liquid phase channel, is provided at the bottom of the reflux separation chamber. The gas phase outlet is located at the upper part of the reflux separation chamber; the liquid phase outlet is located at the bottom of the shell.

[0007] The distillation column provided by this invention has the advantages of compact structure, reduced pressure drop, and improved mass and heat transfer. A detailed analysis follows:

[0008] (1) The distillation column provided by this utility model has the heat exchanger and reflux separation chamber set inside the distillation column, making the whole device structure more compact and easy to install and improve.

[0009] (2) The distillation column provided by this utility model places the heat exchanger and reflux separation chamber inside the distillation column, thereby eliminating the need to install pipes and valves connecting the distillation column. Pipes and valves are the key reasons for the pressure drop of the entire system. After eliminating pipes and valves, the pressure drop of the entire distillation column is significantly reduced, saving the operating cost of the distillation column.

[0010] (3) The present invention provides that by setting a second fluid channel, the liquid phase after separation in the reflux separation chamber can be directly returned from the second fluid channel to the heat and mass transfer section for further distillation separation, which eliminates the need for pipes and valves, further reducing pressure drop and saving operating costs of the distillation column.

[0011] (4) The heat exchanger of this utility model is set inside the distillation column, and the gap between the reflux separation chamber and the shell forms a first fluid channel. The first fluid channel allows the material to be transported from bottom to top to the top of the heat exchanger and then downward to the heat exchanger for countercurrent heat exchange, which significantly improves the mass transfer and heat transfer effect.

[0012] Preferably, the heat exchanger is an aluminum plate-fin heat exchanger.

[0013] This invention preferably uses an aluminum plate-fin heat exchanger, which has a larger heat exchange area per unit volume and higher heat exchange efficiency compared to conventional tube heat exchangers.

[0014] Preferably, the heat exchanger is located at the exact center of the cross-section of the shell, and there are gaps between the heat exchanger and the shell on all four sides.

[0015] The present invention preferably has gaps between the heat exchanger and the shell on all four sides, so that when the material is transported from the bottom up from the periphery of the heat exchanger, it can achieve a certain heat exchange effect. When the material is transported from the top of the heat exchanger downward, it can continue to exchange heat with the heat exchanger, thereby improving the heat exchange efficiency.

[0016] Preferably, the heat exchanger includes a refrigerant inlet and a refrigerant outlet, the refrigerant inlet being located on the lower side of the heat exchanger and the refrigerant outlet being located on the upper side of the heat exchanger.

[0017] Preferably, the distillation column further includes a liquid phase distribution component.

[0018] Preferably, the liquid phase distribution component is disposed between the second fluid channel and the heat and mass transfer section.

[0019] The present invention preferably sets up a liquid phase distribution component between the second fluid channel and the heat and mass transfer section, which can redistribute the refluxed liquid phase, thereby improving the heat and mass transfer effect of the heat and mass transfer section, and thus improving the distillation separation effect.

[0020] Preferably, one end of the liquid phase distribution component is fixedly connected to the housing, and the other end, away from the housing, is suspended in the air.

[0021] Preferably, the liquid phase distribution assembly includes a blocking element and a liquid receiving tank disposed near one end of the shell, and a liquid phase distributor disposed at the center of the distillation column.

[0022] The present invention preferably provides a blocking element and a liquid receiving tank at one end of the liquid phase distribution component, which can collect and block the remaining liquid phase, thereby making it more convenient to uniformly distribute the liquid phase through the liquid phase distributor.

[0023] This invention does not impose any special restrictions on the liquid phase distributor in the above structure. Any device and method known to those skilled in the art for use in liquid phase distributors can be adopted, and adjustments can be made according to the actual device.

[0024] Preferably, the reflux separation chamber is a cavity formed between the upper plate, side plate, lower plate and shell.

[0025] The reflux separation chamber of this invention is preferably provided with a side plate. The side plate increases the height space for gas-liquid separation, improves the gas-liquid separation effect, and reduces liquid entrainment in the outlet gas phase.

[0026] This utility model does not impose any special restrictions on the height of the side plate in the above structure. The height can be well known to those skilled in the art, or it can be adjusted according to the actual structure. For example, it can be 1m to 5m, such as 1m, 1.5m, 2m, 2.5m, 3m, 3.5m, 4m, 4.5m or 5m, etc.

[0027] Preferably, the upper plate and the side plate are arranged perpendicularly.

[0028] Preferably, the lower plate and the side plate are set at an obtuse angle.

[0029] The present invention preferably has an obtuse angle between the lower plate and the side plate, which is more conducive to the transport of the liquid phase under the action of gravity.

[0030] Preferably, the obtuse angle is in the range of 95 to 120°, for example, it can be 95°, 96°, 98°, 100°, 101°, 105°, 110°, 115° or 120°.

[0031] Preferably, the upper plate is in communication with the bottom of the heat exchanger.

[0032] Preferably, the end of the reflux separation chamber connected to the shell and the end of the liquid phase distribution assembly connected to the shell are located on the same axis.

[0033] Preferably, the second fluid channel is located on the axis of the end of the reflux separation chamber that is connected to the housing.

[0034] Preferably, from the reflux separation chamber downwards, the housing further includes a heat transfer and mass transfer section and an inlet material separation section in sequence.

[0035] Preferably, the distillation column further includes a material inlet, which is disposed on the shell and located in the inlet material separation section.

[0036] Preferably, the distillation column further includes a skirt seat disposed below the shell.

[0037] Preferably, the distillation column further includes a vent at the top of the shell.

[0038] The operation method of the distillation column provided by this utility model includes the following steps:

[0039] The material enters the inlet material separation section from the material inlet, where the gas phase is conveyed upward and the liquid phase is conveyed downward to the liquid phase outlet;

[0040] The upward-conveyed gas phase undergoes heat and mass transfer in the heat and mass transfer section, and then is conveyed to the periphery of the heat exchanger through the first fluid channel, and then to the top of the heat exchanger. It is then conveyed downward to the interior of the heat exchanger to exchange heat with the refrigerant in the heat exchanger. After heat exchange, the material is conveyed downward to the reflux isolation chamber, where gas-liquid separation takes place. The gas phase is discharged from the gas phase outlet, while the liquid phase is conveyed downward from the second fluid channel to the inside of the baffle of the liquid phase distribution assembly. After being uniformly distributed by the liquid phase distributor, it is conveyed to the heat and mass transfer section for circulating distillation. The separated liquid phase is discharged from the bottom liquid phase outlet.

[0041] The heat exchange method in this invention is countercurrent heat exchange.

[0042] The heat and mass transfer section of this invention is internally equipped with packing material or trays.

[0043] This invention does not impose any special restrictions on the form of the packing material, and packing materials well known to those skilled in the art can be used, such as bulk packing or packaged packing. Bulk packing includes Raschig rings, corrugated rings, saddle rings, Pall rings, ceramic balls or metal balls, etc., while packaged packing includes corrugated plate packing, honeycomb packing or metal mesh packing, etc.

[0044] There are no special restrictions on the materials that this utility model can target. It can be a pure gaseous feed, which is separated into a liquid phase after distillation and cooling heat exchange; it can also be a two-phase feed of gas and liquid, which is separated by distillation; or it can be a pure liquid feed. When the column is designed for a pure liquid feed, a reboiler is provided at the bottom of the distillation column to provide heat for the vaporization of the liquid phase of the feed.

[0045] Compared with the prior art, the present invention has at least the following beneficial effects:

[0046] The distillation column provided by this utility model integrates the top heat exchanger and reflux separation chamber into the column top, making it a compact structure that avoids external equipment placement and connecting pipes. This significantly reduces the external space required and the column height, facilitating construction and installation, reducing gas pressure drop losses, and minimizing irreversible losses. Furthermore, the preferred heat exchanger is an aluminum plate-fin heat exchanger, operating in a counter-current manner, resulting in high heat exchange efficiency. This improves the condensation effect of the gas at the top of the column, reduces costs and energy consumption, and enhances heat and mass transfer, thereby increasing the column's separation efficiency. Attached Figure Description

[0047] Figure 1 This is a front view of the distillation column provided in Embodiment 1 of this utility model.

[0048] Figure 2 This is a top view of the heat exchanger provided in Embodiment 1 of this utility model.

[0049] In the diagram, 1. Skirt; 2. Lower head; 3. Material inlet; 4. Heat and mass transfer section; 5. Packing; 6. Liquid phase distribution assembly; 7. First fluid channel; 8. Reflux separation chamber; 9. Heat exchanger lower sealing plate; 10. Heat exchanger; 11. Refrigerant outlet; 12. Vent; 13. Upper head; 14. Refrigerant inlet; 15. Upper plate; 16. Gas phase outlet; 17. Side plate; 18. Lower plate; 19. Second fluid channel; 20. Inlet material separation section; 21. Liquid phase outlet. Detailed Implementation

[0050] To facilitate understanding of this utility model, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as specific limitations on this utility model.

[0051] It should be understood that in the description of this utility model, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this utility model and for 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 utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0052] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0053] Those skilled in the art should understand that this utility model necessarily includes the necessary pipelines, conventional valves and general pump equipment for achieving complete process, but the above content is not the main utility model point of this utility model. Those skilled in the art can add layouts themselves based on the process flow and equipment structure selection. This utility model does not make any special requirements or specific limitations in this regard.

[0054] Example 1

[0055] This embodiment provides a distillation column, such as Figures 1-2 As shown, the distillation column includes a shell, a heat exchanger 10, a reflux separation chamber 8, a gas phase outlet 16, and a liquid phase outlet 21.

[0056] The reflux separation chamber 8 and the heat exchanger 10 are disposed inside the shell. The reflux separation chamber 8 is located below the heat exchanger 10, and the top of the reflux separation chamber 8 is connected to the bottom of the heat exchanger 10. There is a gap between the reflux separation chamber 8 and the shell to form a first fluid channel 7. A second fluid channel 19 is provided at the bottom of the reflux separation chamber 8. The second fluid channel 19 is a liquid phase channel. The gas phase outlet 16 is located at the upper part of the reflux separation chamber 8. The liquid phase outlet 21 is located at the bottom of the shell.

[0057] The heat exchanger 10 is an aluminum plate-fin heat exchanger 10. The heat exchanger 10 is located at the center of the shell's cross-section, and there are gaps between the heat exchanger 10 and the shell on all four sides. The heat exchanger 10 includes a refrigerant inlet 14 and a refrigerant outlet 11. The refrigerant inlet 14 is located on the lower side of the heat exchanger 10, and the refrigerant outlet 11 is located on the upper side of the heat exchanger 10. A lower sealing plate 9 is provided at the bottom of the heat exchanger 10.

[0058] The distillation column further includes a liquid phase distribution component 6; the liquid phase distribution component 6 is disposed between the second fluid channel 19 and the heat and mass transfer section 4. One end of the liquid phase distribution component 6 is fixedly connected to the shell, and the other end away from the shell is suspended; the liquid phase distribution component 6 includes a blocking element and a liquid receiving tank disposed near the end of the shell, and a liquid phase distributor disposed at the center of the distillation column.

[0059] The reflux separation chamber 8 is a cavity formed between the upper plate 15, the side plate 17, the lower plate 18, and the shell; the upper plate 15 and the side plate 17 are arranged perpendicularly; the lower plate 18 and the side plate 17 are arranged at an obtuse angle. The obtuse angle is 100°. The upper plate 15 is in communication with the bottom of the heat exchanger 10.

[0060] The end of the reflux separation chamber 8 connected to the housing and the end of the liquid phase distribution assembly 6 connected to the housing are located on the same axis. The second fluid channel 19 is located on the axis of the end of the reflux separation chamber 8 connected to the housing.

[0061] From the reflux separation chamber 8 downwards, the shell also includes a heat and mass transfer section 4 and an inlet material separation section 20 in sequence; the heat and mass transfer section 4 is filled with packing 5; the distillation column also includes a material inlet 3, which is located on the shell and in the inlet material separation section 20; the shell also includes an upper head 13 at the top and a lower head 2 at the bottom. The distillation column also includes a skirt 1 located below the shell; the distillation column also includes a vent 12 located at the top of the shell, which is located at the top of the upper head 13; the liquid phase outlet 21 is located at the bottom of the lower head 2.

[0062] The operation method of the distillation column provided in this embodiment includes the following steps:

[0063] The material enters the inlet material separation section from the material inlet, where the gas phase is conveyed upward and the liquid phase is conveyed downward to the liquid phase outlet;

[0064] The upward-conveyed gas phase undergoes heat and mass transfer in the heat and mass transfer section, and then is conveyed to the periphery of the heat exchanger through the first fluid channel, and then to the top of the heat exchanger. It is then conveyed downward to the interior of the heat exchanger to exchange heat with the refrigerant in the heat exchanger. After heat exchange, the material is conveyed downward to the reflux isolation chamber, where gas-liquid separation takes place. The gas phase is discharged from the gas phase outlet, while the liquid phase is conveyed downward from the second fluid channel to the inside of the baffle of the liquid phase distribution assembly. After being uniformly distributed by the liquid phase distributor, it is conveyed to the heat and mass transfer section for circulating distillation. The separated liquid phase is discharged from the bottom liquid phase outlet.

[0065] Taking the separation of the top material of the demethanizing column as an example, the distillation column provided in this embodiment does not require the installation of too many valves and pipelines, thus greatly reducing the pressure drop. Compared with the top heat exchanger and gas-liquid separation chamber being located outside the column, the pressure drop in this embodiment can be reduced by 20-30 kPa. Moreover, this embodiment sets up a reflux separation chamber below the heat exchanger, so the heat exchanger can achieve a better heat exchange effect with a smaller heat exchange area. A larger heat exchange area can be achieved without increasing the diameter of the original distillation column. Compared with the distillation column provided by CN109966770A, the distillation column provided by CN109966770A uses a tubular heat exchanger and performs gas-liquid separation directly in the heat exchanger. In order to achieve this effect, it is necessary to reduce the material conveying speed in the heat exchanger. Therefore, a larger heat exchange tube flow area is required to reduce the material conveying speed, which leads to a large cross-sectional area of ​​the distillation column and a significant increase in equipment cost.

[0066] Example 2

[0067] This embodiment provides a distillation column, which is the same as that in Embodiment 1 except that the obtuse angle is 95°, and will not be described again here.

[0068] Example 3

[0069] This embodiment provides a distillation column, which is the same as that in Embodiment 1 except that the obtuse angle is 120°, and will not be described again here.

[0070] Examples 2 and 3 can achieve similar technical effects as Example 1.

[0071] Example 4

[0072] This embodiment provides a distillation column, which is the same as that in Embodiment 1 except that it does not have side plates and instead directly connects the upper plate and the lower plate. It will not be described again here.

[0073] In this embodiment, the lack of a side plate results in insufficient gas-liquid separation height in the reflux separation chamber, leading to poor gas-liquid separation and a large amount of liquid phase entrained in the gas phase outlet. Compared to Example 4, Example 1 demonstrates better distillation separation.

[0074] Comparative Example 1

[0075] This comparative example provides a distillation column, which is the same as in Example 1 except that it does not have a second fluid channel, but instead has a liquid phase outlet on the lower side of the reflux separation chamber and supplies liquid phase to the liquid phase distribution assembly through valves and pipelines. It will not be described again here.

[0076] In this comparative example, the pressure drop during overall unit operation increased significantly due to the replacement of the second fluid passage with external valves and pipes.

[0077] This utility model has been described in detail through the above embodiments. However, this utility model is not limited to the above detailed features, that is, it does not mean that this utility model must rely on the above detailed features to be implemented. Those skilled in the art should understand that any improvements to this utility model, equivalent substitutions for the selected technical features, additions of auxiliary technical features, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this utility model.

Claims

1. A distillation column, characterized in that, The distillation column includes a shell, a heat exchanger, a reflux separation chamber, a gas phase outlet, and a liquid phase outlet; The reflux separation chamber and the heat exchanger are disposed inside the shell, the reflux separation chamber is located below the heat exchanger, and the top of the reflux separation chamber is connected to the bottom of the heat exchanger; The reflux separation chamber and the housing have a gap to form a first fluid channel; The bottom of the reflux separation chamber is provided with a second fluid channel, which is a liquid phase channel; The gas phase outlet is located at the upper part of the reflux separation chamber; The liquid phase outlet is located at the bottom of the shell.

2. The distillation column according to claim 1, characterized in that, The heat exchanger is an aluminum plate-fin heat exchanger.

3. The distillation column according to claim 1, characterized in that, The distillation column also includes a liquid phase distribution component; The liquid phase distribution component is disposed between the second fluid channel and the heat and mass transfer section.

4. The distillation column according to claim 3, characterized in that, One end of the liquid phase distribution component is fixedly connected to the housing, and the other end, away from the housing, is suspended in the air. The liquid phase distribution assembly includes a blocking element and a liquid receiving tank disposed near one end of the shell, and a liquid phase distributor disposed at the center of the distillation column.

5. The distillation column according to claim 4, characterized in that, The reflux separation chamber is a cavity formed between the upper plate, side plate, lower plate and shell; The upper plate and the side plate are arranged perpendicularly to each other; The lower plate and the side plate are set at an obtuse angle.

6. The distillation column according to claim 5, characterized in that, The obtuse angle ranges from 95° to 120°.

7. The distillation column according to claim 5, characterized in that, The upper plate is connected to the bottom of the heat exchanger.

8. The distillation column according to claim 5, characterized in that, The end of the reflux separation chamber connected to the shell and the end of the liquid phase distribution component connected to the shell are located on the same axis.

9. The distillation column according to claim 8, characterized in that, The second fluid channel is located on the axis of the end of the reflux separation chamber that is connected to the housing.

10. The distillation column according to any one of claims 1 to 9, characterized in that, Downward from the reflux separation chamber, the housing also includes, in sequence, a heat transfer and mass transfer section and an inlet material separation section; The distillation column also includes a material inlet, which is disposed on the shell and located in the inlet material separation section; The distillation column also includes a skirt seat disposed below the shell; The distillation column also includes a vent located at the top of the shell.

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