A rectification column overhead vapor phase split reboiler

Abstract

The utility model belongs to the field of chemical distillation discloses a rectifying column top gas phase partial flow type reboiling device, include: the gas -liquid separation device includes at least one for changing steam flow path's impedance component, impedance component is configured as: intercept, collision and aggregation effect to the liquid drop entrained in steam, make separated liquid under the action of gravity can reflux, allow the gas phase part in steam to penetrate and pass after changing flow direction, complete gas -liquid separation before steam enters the airflow channel, and buffer steam's impact to the airflow channel inner wall, the introduction of impedance component, through changing steam's flow path, dissipate its kinetic energy, convert concentrated, destructive impact force into dispersed, controllable flow, thereby be favorable to alleviate the impact and wear and tear to the airflow channel, effectively restrain vibration and noise, prolong the service life of equipment.

Description

Technical Field

[0001] This disclosure pertains to the field of chemical distillation, specifically relating to a top vapor-phase split reboiler for a distillation column. Background Technology

[0002] Distillation is the most widely used separation technology in petroleum, chemical and other fields, and its process consumes a huge amount of energy. The reboiler, the core component of the distillation column, is the power source for the continuous boiling of the material inside the column and the generation of rising steam, and it is also the main energy-consuming equipment in the entire distillation process. Traditional reboilers usually require an external heat source, such as fresh steam or hot oil, to provide heat to the material in the bottom of the column through a wall-type heat exchanger. The consumption of this external heat source constitutes a major part of the unit's operating costs.

[0003] To reduce energy consumption, the industry has proposed heat integration technology. One important energy-saving measure is utilizing the heat from the high-temperature vaporous material at the top of the distillation column as a heat source for the reboiler. Specifically, a portion of the vapor distilled from the top of the column is diverted and directly or indirectly introduced into the reboiler as a heat medium. However, this technology faces significant technical challenges in engineering practice:

[0004] Because of the height difference between the top outlet of the distillation column and the condenser connected to the next process stage, when the condenser height is lower than the top of the distillation column, the gas flow channel connecting the top outlet and the condenser inlet forms a bend at the end of the top outlet. This causes the high-speed outflowing vapor to directly impact the inner wall of the bend in the gas flow channel. This continuous impact generates vibration and noise, and leads to erosion and wear in this localized area, seriously affecting the service life and operational safety of the equipment. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this disclosure is to provide a distillation column top vapor-phase split reboiler, which solves the problems of equipment erosion and wear, and high system vibration and noise caused by the direct impact of the split vapor at the pipe turning point and the unstable flow of the gas-liquid two-phase flow in existing technologies.

[0006] The objective of this disclosure can be achieved through the following technical solutions:

[0007] A distillation column top vapor-phase split reboiler includes: a distillation column, the top of which is provided with an outlet for discharging the top vapor phase;

[0008] An airflow channel has its inlet end connected to the outlet, and the central axis of the airflow channel is not parallel to the central axis of the outlet, so that the main direction of the steam flowing out of the outlet intersects the inner wall of the airflow channel.

[0009] A gas-liquid separation device is installed in the connection section between the outlet and the inlet end of the gas flow channel;

[0010] The gas-liquid separation device includes at least one impedance component for changing the steam flow path, the impedance component being configured as follows:

[0011] It intercepts, collides with, and aggregates liquid droplets entrained in the steam, allowing the separated liquid to flow back under the influence of gravity;

[0012] Allowing the gaseous portion of steam to penetrate and pass through after changing the flow direction;

[0013] Gas-liquid separation is completed before steam enters the airflow channel, and the impact of steam on the inner wall of the airflow channel is buffered.

[0014] In some disclosures, the gas-liquid separation device includes a buffer chamber, the flow cross-sectional area of ​​which is larger than the flow cross-sectional area of ​​the outlet.

[0015] In some disclosures, the impedance member includes a lower filter screen, the end of the outlet is provided with a lower filter screen, and the inner side of the lower filter screen is provided with a plurality of filter holes at equal intervals.

[0016] In some disclosures, the lower filter screen is configured such that its cross-sectional area near the end of the distillation column gradually increases in the direction of steam outflow.

[0017] In some disclosures, the impedance member includes an upper filter screen, which is disposed directly above the lower filter screen, and a connecting rod is fixed to the lower end face of the upper filter screen, and the upper filter screen is fixed to the end of the outlet via the connecting rod.

[0018] In some disclosures, the upper filter is located within a buffer cavity.

[0019] In some disclosures, the lower filter screen is configured such that its cross-sectional area near the end of the distillation column gradually decreases in the direction of steam outflow.

[0020] In some disclosures, the inner wall of the upper filter screen is provided with multiple radial grooves, which are equidistantly arranged around the central axis of the outlet.

[0021] In some disclosures, an elastic element is provided between the upper filter screen and the lower filter screen, and a guide hole adapted to the connecting rod is opened on the inner side of the lower filter screen, and the lower filter screen is slidably disposed along the axial direction of the outlet.

[0022] In some disclosures, the outlet end of the gas flow channel is sequentially connected to a condenser, a reflux tank, and the heated side inlet of the reboiler. The heated side outlet of the reboiler is connected to the distillation column through a reflux pipeline, forming a complete closed-loop cycle of gaseous material diversion, condensation, storage, reboiling, and return to the distillation column.

[0023] The explanations of the nouns, conjunctions, or adjectives used in the above technical solutions are as follows:

[0024] A fixed connection refers to a connection in which parts or components are fixed in place and there is no relative movement between them;

[0025] A rotating connection is a connection between parts that allows the parts to rotate relative to each other.

[0026] Threaded connections are a type of detachable fixed connection with advantages such as simple structure, reliable connection, and convenient assembly and disassembly. They are widely used in mechanical engineering and connection structure fields.

[0027] A sliding connection is a connection between parts that allows the parts to slide against each other.

[0028] The beneficial effects of this disclosure are:

[0029] 1. By setting impedance components, liquid droplets entrained in the steam are actively intercepted, collided and gathered, realizing gas-liquid separation before the steam enters the downstream system; in this process, the liquid content in the steam per unit volume is reduced, and the steam output is clean and dry when it enters the next process, thereby significantly improving the heat transfer efficiency and process stability of subsequent equipment such as reboilers.

[0030] 2. The introduction of impedance components changes the flow path of steam and dissipates its kinetic energy, transforming the concentrated and destructive impact force into a dispersed and controllable flow. This helps to alleviate the impact and wear on the airflow channel, effectively suppresses vibration and noise, and extends the service life of the equipment. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this disclosure;

[0033] Figure 2 This is a schematic diagram of the overall structure of the gas-liquid separation device according to an embodiment of this disclosure;

[0034] Figure 3 This is a top view schematic diagram of a gas-liquid separation device according to an embodiment of the present disclosure;

[0035] Figure 4 This is a schematic cross-sectional view AA in the front view of an embodiment of this disclosure;

[0036] Figure 5This is a schematic diagram of the isometric section BB in the front view of an embodiment of this disclosure.

[0037] In the diagram: 1. Distillation column; 101. Outlet; 2. Gas flow channel; 3. Gas-liquid separation device; 30. Impedance component; 31. Buffer chamber; 32. Lower filter screen; 33. Upper filter screen; 321. Filter hole; 322. Guide hole; 331. Radial channel; 332. Connecting rod; 34. Elastic element; 4. Condenser; 5. Reflux tank; 6. Reboiler. Detailed Implementation

[0038] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0039] Please refer to Figures 1 to 5 A distillation column top vapor phase split reboiler includes: a distillation column 1, which has an outlet 101 at the top for discharging the top vapor phase;

[0040] The airflow channel 2 has its inlet end connected to the outlet 101, and the central axis of the airflow channel 2 is not parallel to the central axis of the outlet 101, so that the main direction of the steam flowing out from the outlet 101 intersects with the inner wall of the airflow channel 2.

[0041] The gas-liquid separation device 3 is disposed in the connecting section between the outlet 101 and the inlet end of the airflow channel 2;

[0042] The gas-liquid separation device 3 includes at least one impedance member 30 for changing the steam flow path, and the impedance member 30 is configured as follows:

[0043] It intercepts, collides with, and aggregates liquid droplets entrained in the steam, allowing the separated liquid to flow back under the influence of gravity;

[0044] Allowing the gaseous portion of steam to penetrate and pass through after changing the flow direction;

[0045] Gas-liquid separation is completed before steam enters the airflow channel 2, and the impact of steam on the inner wall of the airflow channel 2 is buffered.

[0046] When the steam in the distillation column moves upward, it passes through the outlet 101 and enters the gas flow channel 2. Since the direction of the outlet 101 is not parallel to the direction of the gas flow channel 2, if the steam moves vertically upward along the outlet 101, it will collide with the inner wall at the connection between the outlet 101 and the gas flow channel 2. The gas-liquid separation device 3 is located at the end of the outlet 101 and the end of the gas flow channel 2, and can separate the liquid and gas in the steam before the steam enters the gas flow channel 2.

[0047] Meanwhile, the gas-liquid separation device 3 includes an impedance member 30. When the steam comes into contact with the impedance member 30, the liquid in the steam is blocked by the impedance member 30 in the gas-liquid device. Subsequently, the liquid blocked by the impedance member 30 falls back into the distillation column under the influence of gravity, while the gas part passes through the impedance member 30 and enters the gas flow channel 2. At the same time, when the steam is separated into gas and liquid, the impact force of the gas in the steam on the inner wall of the gas flow channel 2 is reduced due to the obstruction of the steam movement path by the impedance member 30.

[0048] Please refer to Figures 2 to 5 The gas-liquid separation device 3 includes a buffer chamber 31, the cross-sectional area of ​​which is larger than the cross-sectional area of ​​which is larger than that of the outlet 101;

[0049] In operation, as the steam rises within the distillation column, it passes through outlet 101 and reaches the airflow channel 2. There, it instantly enters the significantly enlarged buffer chamber 31 through the relatively narrow inner cavity of outlet 101. At this point, according to fluid dynamics principles, the steam's flow velocity rapidly decreases, and its carrying capacity (i.e., its ability to carry droplets) is significantly weakened. Within the low-velocity, loose buffer chamber 31, condensed droplets in the mixed fluid settle and separate from the steam under their own gravity. Simultaneously, due to the sudden expansion of the flow cross-section, the fluid flow direction changes, and a portion of the steam diffuses towards the inner wall of the buffer chamber 31, reducing the upward impact force.

[0050] Please refer to Figure 4 and Figure 5 The impedance component 30 includes a lower filter screen 32. The lower filter screen 32 is provided at the end of the outlet 101, and a plurality of filter holes 321 are provided through the inner side of the lower filter screen 32 at equal intervals.

[0051] The solid part of the filter screen 32 is used to obstruct the direct passage of airflow during the rising process of steam. Because of its small mass and low inertia, the steam itself can change direction relatively flexibly and pass through the filter holes 321. However, the liquid droplets in the steam, because their density and inertia are greater than that of the steam, are difficult to change direction quickly with the airflow, and thus directly collide with the solid filaments or plates of the filter screen, are effectively captured, and then re-enter the distillation column under the action of gravity.

[0052] Please refer to Figures 3 to 5 The lower filter screen 32 is configured such that its cross-sectional area near the end of the distillation column gradually increases along the direction of steam outflow.

[0053] The lower filter screen 32 is a truncated cone with the tip pointing downwards. The lower filter screen 32 is cone-shaped as a whole. The vertically moving steam carrying liquid droplets directly impacts the outer wall of the lower filter screen 32, while a large number of liquid droplets flow smoothly down the downward cone surface under the action of gravity and gather at the bottom tip of the lower filter screen 32. The gathered droplets quickly drip into the distillation column under the action of gravity.

[0054] Please refer to Figures 3 to 5 The impedance component 30 includes an upper filter screen 33, which is disposed directly above the lower filter screen 32. A connecting rod 332 is fixed to the lower end face of the upper filter screen 33, and the upper filter screen 33 is fixed to the end of the outlet 101 by the connecting rod 332.

[0055] The upper filter screen 33 is located directly above the lower filter screen 32. The lower filter screen 32 comes into contact with the steam first, so the lower filter screen 32 is responsible for the initial separation of the steam.

[0056] Some of the steam that has undergone primary separation does not come into contact with the lower filter screen 32 because it passes directly through the filter holes 321. Therefore, the steam that has undergone primary separation may still carry some droplets on its inner side. The function of the upper filter screen 33 is to further separate the droplets that were not treated in the primary separation by using secondary inertial collision and the double-layer filter structure, thereby increasing the content of liquid droplets in the steam per unit volume.

[0057] This relatively improves the purity and quality of the "effective" gaseous working fluid. This makes the steam per unit volume more thermally valuable.

[0058] Please refer to Figures 3 to 5 The upper filter 33 is located inside the buffer cavity 31;

[0059] After the steam enters the larger diameter buffer chamber 31, the steam flow rate decreases rapidly. At this time, the steam passing through the lower filter screen 32 enters the buffer chamber 31 before passing through the upper filter screen 33. The steam flow rate decreases, and the gas's ability to carry liquid droplets decreases. Inside the buffer chamber 31, the steam cooperates with the upper filter screen 33 to reduce the secondary entrainment of liquid droplets caused by the steam passing through the upper filter screen 33, thereby further reducing the water content of the steam per unit volume.

[0060] Please refer to Figure 3 The lower filter screen 32 is configured such that its cross-sectional area near the end of the distillation column gradually decreases along the direction of steam outflow;

[0061] The lower filter screen 32 is a frustum-shaped structure with its tip pointing upwards. Since the steam entering the airflow channel 2 has its upward momentum reduced by the lower filter screen 32 and the buffer chamber 31, in order to ensure that the gaseous part of the steam passes smoothly through the upper filter screen 33, the droplets gathered at the lower end of the lower filter screen 32 are guided smoothly and evenly along the inside of the upper filter screen 33 and dispersed to the maximum cross-section of the entire upper filter screen 33, thereby separating them from the droplet position of the filter hole 321 on the lower filter screen 32. This avoids the situation where the airflow becomes turbulent when the steam below passes through the lower filter screen 32 during the process of the droplets dripping downwards from the upper filter screen 33.

[0062] Please refer to Figure 4 and Figure 5 The inner wall of the upper filter screen 33 is provided with a plurality of radial grooves 331, which are equidistantly arranged around the central axis of the outlet 101.

[0063] When the projection of the upper filter screen 33 completely covers the lower filter screen 32, due to the misaligned arrangement of the through holes and slots, steam cannot pass through the two filter screens directly and vertically continuously from an axial perspective. This means that when steam moves vertically upward from the through holes of the lower filter screen 32, the effective flow area through which it can pass directly and unobstructed is significantly reduced. The steam must slow down, change direction, and find and enter the radial slot 331 of the upper filter screen 33 within the chamber between the upper and lower filter screens 32.

[0064] Please refer to Figure 4 An elastic element 34 is provided between the upper filter screen 33 and the lower filter screen 32, and a guide hole 322 adapted to the connecting rod 332 is provided on the inner side of the lower filter screen 32, and the lower filter screen 32 is slidably arranged along the axial direction of the outlet 101.

[0065] When the elastic element 34 is in its original length state, the lower end of the elastic element 34 is only slightly deformed by the weight of the lower filter screen 32. The elastic element 34 is a spring. When the steam moves upward and flows through the lower filter screen 32, the steam exerts an upward thrust on the lower filter screen 32, pushing the lower filter screen 32 to slide upward along the axis and compressing the elastic element 34. Then, after the upward thrust of the steam weakens, the elastic element 34 rebounds downward under the influence of the elastic restoring force. During this process, the change in airflow of steam through the lower filter screen 32 causes the lower filter screen 32 to float up and down, thereby shaking off the liquid on the lower filter screen 32.

[0066] Please refer to Figure 1 The outlet end of the gas flow channel 2 is sequentially connected to the condenser 4, the reflux tank 5, and the heated side inlet of the reboiler 6. The heated side outlet of the reboiler 6 is connected to the distillation column 1 through a reflux pipeline, forming a complete closed loop of gas phase material diversion, condensation, storage, reboiling and return to the distillation column 1.

[0067] A portion of high-temperature gaseous material is drawn from the outlet 101 at the top of distillation column 1 and flows through a dedicated gas-liquid separation and buffer device for purification and flow stabilization. It then enters the heat source side of reboiler 6 as a high-temperature heat source. Inside reboiler 6, the vapor at the top of the column releases latent heat, heating the process liquid circulating from the bottom of the column to make it boil, while the vapor itself is condensed. The condensate eventually returns to distillation column 1, thus forming a closed-loop thermal energy cycle system that directly uses the waste heat of the high-temperature gaseous phase at the top of the column to drive the reboiling at the bottom of the column. This reduces the demand for external heat sources and achieves efficient integration of process energy and energy-saving operation.

[0068] To ensure smooth gas flow in the airflow channel 2, a delivery pump can be installed. The core function of the delivery pump is to provide power to force the condensate in the return tank 5 to be delivered and establish a stable flow rate and pressure, so that it can overcome pipeline resistance, level difference and pressure drop inside the reboiler 6, and thus reliably inject it into the heated side of the reboiler 6.

[0069] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of this disclosure. Those skilled in the art should understand that this disclosure is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this disclosure. Various changes and modifications can be made to this disclosure without departing from its spirit and scope, and all such changes and modifications fall within the scope of this disclosure as claimed.

Claims

1. A distillation column top vapor-phase split-flow reboiler, characterized in that, include: A distillation column (1) is provided at the top for discharging the top gas phase; The airflow channel (2) has its inlet end connected to the outlet (101), and the central axis of the airflow channel (2) is not parallel to the central axis of the outlet (101), so that the main direction of the steam flowing out from the outlet (101) intersects with the inner wall of the airflow channel (2). A gas-liquid separation device (3) is installed in the connection section between the outlet (101) and the inlet end of the airflow channel (2); The gas-liquid separation device (3) includes at least one impedance member (30) for changing the steam flow path, and the impedance member (30) is configured as follows: It intercepts, collides with, and aggregates liquid droplets entrained in the steam, allowing the separated liquid to flow back under the influence of gravity; Allowing the gaseous portion of steam to penetrate and pass through after changing the flow direction; Gas-liquid separation is completed before steam enters the airflow channel (2), and the impact of steam on the inner wall of the airflow channel (2) is buffered.

2. The distillation column top vapor-phase split reboiler according to claim 1, characterized in that, The gas-liquid separation device (3) includes a buffer chamber (31), the cross-sectional area of ​​which is larger than the cross-sectional area of ​​the outlet (101).

3. The distillation column top vapor-phase split reboiler according to claim 2, characterized in that, The impedance component (30) includes a lower filter screen (32), and the lower filter screen (32) is provided at the end of the outlet (101), and a plurality of filter holes (321) are provided equidistantly through the inner side of the lower filter screen (32).

4. The distillation column top vapor-phase split reboiler according to claim 3, characterized in that, The lower filter (32) is configured such that its cross-sectional area near the end of the distillation column gradually increases along the direction of steam outflow.

5. A distillation column top vapor-phase split reboiler according to claim 3, characterized in that, The impedance component (30) includes an upper filter screen (33), which is located directly above the lower filter screen (32). A connecting rod (332) is fixed to the lower end face of the upper filter screen (33), and the upper filter screen (33) is fixed to the end of the outlet (101) by the connecting rod (332).

6. A distillation column top vapor-phase split reboiler according to claim 5, characterized in that, The upper filter (33) is located inside the buffer cavity (31).

7. A distillation column top vapor-phase split reboiler according to claim 6, characterized in that, The lower filter (32) is configured such that its cross-sectional area near the end of the distillation column gradually decreases along the direction of steam outflow.

8. A distillation column top vapor-phase split reboiler according to claim 7, characterized in that, The inner wall of the upper filter screen (33) is provided with a plurality of radial through grooves (331), which are equidistantly arranged around the central axis of the outlet (101).

9. A distillation column top vapor-phase split reboiler according to claim 8, characterized in that, An elastic element (34) is provided between the upper filter screen (33) and the lower filter screen (32), and a guide hole (322) adapted to the connecting rod (332) is opened on the inner side of the lower filter screen (32), and the lower filter screen (32) is slidably arranged along the axial direction of the outlet (101).

10. A distillation column top vapor-phase split reboiler according to claim 1, characterized in that, The outlet end of the gas flow channel (2) is sequentially connected to the condenser (4), the reflux tank (5) and the heated side inlet of the reboiler (6). The heated side outlet of the reboiler (6) is connected to the distillation column (1) through a reflux pipeline, forming a complete closed loop of gas phase material diversion, condensation, storage, reboiling and return to the distillation column (1).

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