Raffinate tower top heat exchange system of adsorption separation unit of aromatic hydrocarbon combination device

Abstract

The utility model relates to two sets of adsorption production systems in an aromatic hydrocarbon factory, in particular to a raffinate tower top heat exchange system of an adsorption separation unit of an aromatic hydrocarbon combination device, which comprises a raffinate tower and a desorption agent regeneration tower, and the raffinate tower is connected to a raffinate tower return tank through a raffinate tower gas phase outlet pipeline. The raffinate tower reflux tank is connected to the raffinate tower through a raffinate reflux pipeline and a raffinate reflux pump, and a raffinate tower top air cooler is arranged on a gas phase outlet pipeline of the raffinate tower; the desorption agent regeneration device is connected to the raffinate tower through a regeneration tower gas phase outlet pipeline, and a regeneration tower gas phase control valve is arranged on the regeneration tower gas phase outlet pipeline; and the regeneration tower gas phase outlet pipeline and the raffinate tower gas phase outlet pipeline are connected through a first overline and a second overline. The tower top flow of the raffinate tower exchanges heat with the tower top flow of the desorption agent regeneration tower, so that the temperature of an outlet of an air cooler at the top of the raffinate tower is increased, the anti-freezing effect is achieved, a heat tracing pipeline is not needed, and the energy loss is reduced.

Description

Technical Field

[0001] This utility model relates to two production systems for adsorption in an aromatics plant, specifically to the heat exchange system at the top of the raffinate tower in the adsorption separation unit of an aromatics combined unit, and belongs to the petrochemical field. Background Technology

[0002] The two adsorption production systems of the aromatics plant require antifreeze and anti-condensation measures for the top air cooling of the evaporator in winter. This necessitates antifreeze treatment for the process from the top of the evaporator to the reflux tank. Installing a heat tracing pipeline through the main steam network will reduce the amount of main steam that generates waste heat, thereby reducing the amount of waste heat power generation. Summary of the Invention

[0003] In view of the defects of the existing technology, the purpose of this utility model is to provide a heat exchange system at the top of the raffinate tower of the adsorption separation unit of the aromatic hydrocarbon complex, which exchanges heat between the top process of the raffinate tower and the top process of the desorbent regeneration tower to achieve the effect of preventing freezing and condensation.

[0004] To achieve the above objectives, the technical solution used in this utility model is as follows: a heat exchange system at the top of the raffinate tower in an aromatic hydrocarbon combined adsorption separation unit, comprising a raffinate tower and a regenerator tower. The gas phase outlet at the top of the raffinate tower is connected to a raffinate tower reflux tank via a raffinate tower gas phase outlet pipeline. The bottom outlet of the raffinate tower reflux tank is connected to the raffinate tower via a raffinate reflux pipeline and a raffinate reflux pump. A raffinate tower top air cooler is installed on the raffinate tower gas phase outlet pipeline. The gas phase outlet at the top of the regenerator tower is connected to... The vapor phase outlet pipeline of the regeneration tower is connected to the evaporator, and a vapor phase control valve for the regeneration tower is installed on the vapor phase outlet pipeline of the regeneration tower. The vapor phase outlet pipeline of the regeneration tower and the vapor phase outlet pipeline of the evaporator are connected by a first cross-line and a second cross-line. The inlet of the first cross-line is connected upstream of the vapor phase control valve of the regeneration tower, and the outlet of the first cross-line is connected upstream of the top air cooler of the evaporator. The inlet of the second cross-line is connected downstream of the top air cooler of the evaporator, and the outlet of the second cross-line is connected downstream of the vapor phase control valve of the regeneration tower.

[0005] Furthermore, a first cross-line valve is provided on the first cross-line, and a second cross-line valve is provided on the second cross-line.

[0006] Furthermore, the gas phase control valve of the regeneration tower includes a first valve and a second valve arranged in series.

[0007] Furthermore, a switch control valve is installed before the inlet of the air cooler at the top of the evaporator, and the first cross-line outlet is located between the switch control valve and the air cooler at the top of the evaporator.

[0008] Furthermore, a temperature controller is provided at the outlet of the air cooler at the top of the evaporator, and the second cross-line inlet is connected downstream of the temperature controller.

[0009] Furthermore, the bottom outlet of the raffinate tower is connected to the bottom outlet pipeline of the raffinate tower, and the bottom pump of the raffinate tower is connected to the bottom outlet pipeline of the raffinate tower. The outlet of the bottom pump of the raffinate tower is connected to the inlet of the desorbent regeneration tower through an outlet branch pipe.

[0010] Furthermore, the bottom outlet pipeline of the evaporator is connected to a evaporator feed-bottom heat exchanger downstream of the outlet branch pipe, and the evaporator feed pipeline is connected to the evaporator inlet via the evaporator feed-bottom heat exchanger.

[0011] Furthermore, the bottom of the raffinate column is equipped with a xylene redistillation column top-raffinate column reboiler and a xylene column top-raffinate column reboiler; a raffinate column side-line buffer tank is provided on the side of the raffinate column.

[0012] Furthermore, the top outlet of the evaporator reflux tank is connected in sequence to the evaporator top gas cooler and the evaporator top gas vent tank via pipelines. The bottom outlet of the evaporator top gas vent tank is connected to the evaporator reflux tank, and the top outlet of the evaporator top gas vent tank is connected to the flare system.

[0013] Furthermore, the regenerator regeneration tower is equipped with a bottom pump for the regenerator redistillation tower and a reboiler for the regenerator redistillation tower; the regenerator regeneration tower is connected to a top exhaust pipeline, and a safety valve is installed on the top exhaust pipeline.

[0014] The beneficial effects of this utility model are as follows: by exchanging heat between the top process of the raffinate tower and the top process of the desorbent regeneration tower, the outlet temperature of the air cooler at the top of the raffinate tower is increased, thereby achieving the effect of preventing freezing and condensation. It is not necessary to install a heat tracing pipeline through the main steam network, thus reducing energy consumption. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the heat exchange system at the top of the raffinate tower in the adsorption separation unit of the aromatic hydrocarbon combined unit of this utility model.

[0016] In the diagram: 1. Residue evaporator, 2. Residue evaporator vapor outlet pipeline, 3. Switch control valve, 4. Residue evaporator top air cooler, 5. Temperature controller, 6. Residue evaporator reflux tank, 7. Residue evaporator reflux pipeline, 8. Residue evaporator reflux pump, 9. Desorbent regeneration tower, 10. Regeneration tower vapor outlet pipeline, 11. First valve, 12. Second valve, 13. First cross-line, 14. Second cross-line, 15. First cross-line valve, 16. Second cross-line valve, 17. Residue evaporator bottom outlet pipeline, 18. Residue evaporator bottom pump, 19. Outlet branch pipe, 20. Residue evaporator feed-bottom heat exchanger, 21. Residue evaporator feed pipeline, 22. Xylene redistillation tower top-residue evaporator reboiler, 23. Xylene tower top-residue evaporator reboiler. 24. Side buffer tank of raffinate tower; 25. Top gas cooler of raffinate tower; 26. Top gas vent tank of raffinate tower; 27. Bottom pump of refluxing agent redistillation tower; 28. Reboiler of refluxing agent redistillation tower; 29. ​​Top exhaust pipeline of regeneration tower. Detailed Implementation

[0017] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0018] See appendix Figure 1The heat exchange system at the top of the raffinate tower in the aromatics combined unit adsorption separation unit includes a raffinate tower 1 and a desorbent regeneration tower 9. The gas phase outlet at the top of the raffinate tower 1 is connected to a raffinate tower reflux tank 6 via a raffinate tower gas phase outlet pipeline 2. The bottom outlet of the raffinate tower reflux tank 6 is connected to the raffinate tower 1 via a raffinate reflux pipeline 7 and a raffinate reflux pump 8. A raffinate tower top air cooler 4 is installed on the raffinate tower gas phase outlet pipeline 2. The gas phase outlet at the top of the desorbent regeneration tower 9 is connected to the raffinate tower 1 via a regeneration tower gas phase outlet pipeline 10. A series of... A first valve 11 and a second valve 12 are connected together. The gas phase outlet pipeline 10 of the regeneration tower and the gas phase outlet pipeline 2 of the evaporator are connected by a first cross-line 13 and a second cross-line 14. The inlet of the first cross-line 13 is connected upstream of the first valve 11, and the outlet of the first cross-line 13 is connected upstream of the air cooler 4 at the top of the evaporator. A first cross-line valve 15 is provided on the first cross-line 11. The inlet of the second cross-line 14 is connected downstream of the air cooler 4 at the top of the evaporator. The outlet of the second cross-line 14 is connected downstream of the second valve 12, and a second cross-line valve 16 is provided on the second cross-line 14.

[0019] Furthermore, a switch control valve 3 is provided before the inlet of the evaporator top air cooler 4, and the outlet of the first cross line 11 is located between the switch control valve 3 and the evaporator top air cooler 4.

[0020] Furthermore, a temperature controller 5 is provided at the outlet of the top air cooler 4 of the evaporator, and the inlet of the second cross line 14 is connected downstream of the temperature controller 5.

[0021] Furthermore, the bottom outlet of the raffinate tower 1 is connected to the bottom outlet pipeline 17 of the raffinate tower, and the bottom pump 18 of the raffinate tower is connected to the bottom outlet pipeline 17 of the raffinate tower. The outlet of the bottom pump 18 of the raffinate tower is connected to the inlet of the desorbent regeneration tower 9 through the outlet branch pipe 19.

[0022] Furthermore, the bottom outlet pipeline 17 of the evaporator is connected to the evaporator feed-bottom heat exchanger 20 downstream of the outlet branch pipe 19, and the evaporator feed pipeline 21 is connected to the inlet of the evaporator 1 via the evaporator feed-bottom heat exchanger 20.

[0023] Furthermore, the bottom of the raffinate column 1 is provided with a xylene redistillation column top-raffinate column reboiler 22 and a xylene column top-raffinate column reboiler 23; and a raffinate column side-line buffer tank 24 is provided on the side of the raffinate column.

[0024] Furthermore, the top outlet of the evaporator reflux tank 6 is connected in sequence to the evaporator top gas cooler 25 and the evaporator top gas vent tank 26 via pipelines. The bottom outlet of the evaporator top gas vent tank 26 is connected to the evaporator reflux tank 6, and the top outlet of the evaporator top gas vent tank 26 is connected to the flare system.

[0025] Furthermore, the regenerator regeneration tower 9 is equipped with a bottom pump for the regenerator redistillation tower and a reboiler for the regenerator redistillation tower; the regenerator regeneration tower 9 is connected to a top exhaust pipe 29 of the regeneration tower, and a safety valve is installed on the top exhaust pipe 29 of the regeneration tower.

[0026] In this embodiment, heat exchange is performed between the top of the desorbent regeneration tower 9 and the inlet of the air cooler 4 at the top of the evaporator tower. The temperature at the top outlet of the desorbent regeneration tower 9 is controlled at around 220°C by the temperature controller 5. When the air cooler 4 at the top of the evaporator tower is not in use during winter, the temperature will increase with the change of ambient temperature when the temperature reaches the inlet of the air cooler 4 at the top outlet of the desorbent regeneration tower 9. This achieves the effect of preventing freezing and condensation, eliminating the need for heat tracing through the control valve 3 to the evaporator tower reflux tank 6 for freezing prevention, avoiding the consumption of main steam heat, and saving energy and reducing consumption.

[0027] When putting it into operation, ensure that the first valve 11 and the second valve 12 are fully open. After slowly opening the first cross-line valve 15, slowly open the second cross-line valve 16. Observe the temperature of the top air cooler 4 of the evaporator through the temperature controller 5. After the temperature reaches the required level, slowly close the first valve 11 to fully close it, open the second cross-line valve 16 until it is fully open, and close the second valve 12. At the same time, adjust the internal operation to stabilize the evaporator 1.

[0028] It should be noted that the parts of this utility model not described in detail are existing technologies.

[0029] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0030] Furthermore, the terms "first" and "second" 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, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0032] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0034] The above-listed embodiments are merely preferred embodiments of this utility model. Obviously, this utility model is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of this utility model should be considered within the protection scope of this utility model.

Claims

1. A heat exchange system at the top of the raffinate tower in an adsorption separation unit of an aromatic hydrocarbon complex, characterized in that: The system includes a raffinate tower and a regenerator regeneration tower. The gas phase outlet at the top of the raffinate tower is connected to a raffinate tower reflux tank via a raffinate tower gas phase outlet pipeline. The bottom outlet of the raffinate tower reflux tank is connected to the raffinate tower via a raffinate reflux pipeline and a raffinate reflux pump. An air cooler is installed on the raffinate tower gas phase outlet pipeline. The gas phase outlet at the top of the regenerator regeneration tower is connected to the raffinate tower via a regeneration tower gas phase outlet pipeline. A regeneration tower gas phase control valve is installed on the regeneration tower gas phase outlet pipeline. The regeneration tower gas phase outlet pipeline and the raffinate tower gas phase outlet pipeline are connected by a first crossover and a second crossover. The inlet of the first crossover is connected upstream of the regeneration tower gas phase control valve, and the outlet of the first crossover is connected upstream of the raffinate tower air cooler. The inlet of the second crossover is connected downstream of the raffinate tower air cooler, and the outlet of the second crossover is connected downstream of the regeneration tower gas phase control valve.

2. The heat exchange system at the top of the raffinate tower in the adsorption separation unit of the aromatic hydrocarbon complex according to claim 1, characterized in that: A first cross-line valve is provided on the first cross-line, and a second cross-line valve is provided on the second cross-line.

3. The heat exchange system at the top of the raffinate tower in the adsorption separation unit of the aromatic hydrocarbon complex according to claim 1 or 2, characterized in that: The gas phase control valve of the regeneration tower includes a first valve and a second valve arranged in series.

4. The heat exchange system at the top of the raffinate tower in the adsorption separation unit of the aromatic hydrocarbon complex according to claim 1 or 2, characterized in that: A switch control valve is installed before the inlet of the air cooler at the top of the evaporator, and the first cross-line outlet is located between the switch control valve and the air cooler at the top of the evaporator.

5. The heat exchange system at the top of the raffinate tower of the adsorption separation unit in the aromatic hydrocarbon complex according to claim 1 or 2, characterized in that: The outlet of the air cooler at the top of the raffinate tower is equipped with a temperature controller, and the second cross-line inlet is connected downstream of the temperature controller.

6. The heat exchange system at the top of the raffinate tower in the adsorption separation unit of the aromatic hydrocarbon complex according to claim 1, characterized in that: The bottom outlet of the raffinate tower is connected to the bottom outlet pipeline of the raffinate tower, and the bottom pump of the raffinate tower is connected to the bottom outlet pipeline of the raffinate tower. The outlet of the bottom pump of the raffinate tower is connected to the inlet of the desorbent regeneration tower through an outlet branch pipe.

7. The heat exchange system at the top of the raffinate tower in the adsorption separation unit of the aromatic hydrocarbon complex according to claim 6, characterized in that: The bottom outlet pipeline of the evaporator is connected to a evaporator feed-bottom heat exchanger downstream of the outlet branch pipe, and the evaporator feed pipeline is connected to the evaporator inlet via the evaporator feed-bottom heat exchanger.

8. The heat exchange system at the top of the raffinate tower in the adsorption separation unit of the aromatic hydrocarbon complex according to claim 1, characterized in that: The bottom of the raffinate column is equipped with a xylene redistillation column top-raffinate column reboiler and a xylene column top-raffinate column reboiler; a raffinate column side-line buffer tank is provided on the side of the raffinate column.

9. The heat exchange system at the top of the raffinate tower in the adsorption separation unit of the aromatic hydrocarbon complex according to claim 1, characterized in that: The top outlet of the evaporator reflux tank is connected in sequence to the evaporator top gas cooler and the evaporator top gas vent tank via pipelines. The bottom outlet of the evaporator top gas vent tank is connected to the evaporator reflux tank, and the top outlet of the evaporator top gas vent tank is connected to the flare system.

10. The heat exchange system at the top of the raffinate tower in the adsorption separation unit of the aromatic hydrocarbon complex according to claim 1, characterized in that: The regenerator regeneration tower is equipped with a bottom pump for the regenerator redistillation tower and a reboiler for the regenerator redistillation tower; the top of the regenerator regeneration tower is connected to an exhaust pipe, and a safety valve is installed on the exhaust pipe.

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