A backheating condensing cavity for rectifying column

Abstract

This utility model discloses a regenerative condenser for a distillation column, belonging to the technical field of chemical engineering separation equipment. It includes a column body, a reboiler connected to the bottom of the column body via a liquid outlet pipe, and a condenser assembly connected to the top of the column body. The reboiler sends steam into the column body through an inlet pipe. It also includes a preheating pipe connected between the outlet pipe at the top of the column body and the condenser assembly. The preheating pipe is fitted around the outer periphery of the inlet pipe in a heat exchange manner, used to preheat the gas flowing out of the column body using the high-temperature steam entering the inlet pipe from the reboiler. This utility model reduces the reflux steam temperature, minimizing the risk of excessively high local temperatures within the column due to steam overheating.

Description

Technical Field

[0001] This utility model relates to the field of chemical engineering separation equipment technology, and in particular to a regenerative condenser for a distillation column. Background Technology

[0002] Distillation is one of the most widely used separation technologies in chemical, petroleum, and pharmaceutical fields. A typical distillation system mainly includes a distillation column, a reboiler at the bottom of the column, and a condenser at the top. Its basic working principle is as follows: taking advantage of the different volatility of the components in the mixture, the liquid mixture is heated at the bottom of the column by the reboiler, generating an upward vapor flow. This vapor flow has multiple countercurrent contacts with the liquid returning to the trays, completing the mass and heat transfer between the gas and liquid phases. Finally, the more volatile components (low-boiling-point components) are enriched at the top of the column. After being condensed by the condenser, part of it is collected as product, and the other part is returned to the column as reflux liquid. The less volatile components (high-boiling-point components) are collected at the bottom of the column and discharged as bottom residue.

[0003] In traditional designs, the secondary steam in the inlet pipe is directly refluxed into the column, and its temperature is significantly higher than the ideal reflux steam temperature of the trays or packing layer. This causes local overheating at the bottom of the column, which disrupts the temperature distribution and equilibrium state within the column. Local overheating at the bottom of the column or the lower trays reduces the mass and heat transfer efficiency between the rising steam and the falling liquid, making it impossible to maintain a stable gas-liquid balance, and ultimately affecting the separation efficiency of the distillation column. Utility Model Content

[0004] The purpose of this invention is to reduce the temperature of the reflux steam and reduce the localized high temperature inside the tower caused by steam overheating.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a regenerative condensing chamber for a distillation column, comprising a column body, a reboiler connected to the bottom of the column body via a liquid outlet pipe, and a condensing assembly connected to the top of the column body, wherein the reboiler sends steam into the column body via an inlet pipe.

[0006] It also includes a preheating pipe, which is connected between the gas outlet pipe at the top of the tower and the condensation assembly. The preheating pipe is fitted around the outer periphery of the gas inlet pipe in the form of heat exchange, and is used to preheat the gas flowing out of the tower by using the high-temperature steam entering the gas inlet pipe from the reboiler.

[0007] As a further description of the above technical solution: the condensation assembly includes a steam collection box, the bottom of which is connected to a preheating pipe via a gas delivery pipe, and the bottom of which is connected to the tower body via a return pipe.

[0008] As a further description of the above technical solution: the inner cavity of the steam collection box is provided with a cooling pipe for introducing a cooling medium, and the cooling pipe is an S-shaped pipe.

[0009] As a further description of the above technical solution: the preheating pipe is an annular pipe, and its inner cavity is provided with several baffles for extending the gas flow path.

[0010] As a further description of the above technical solution: the preheating pipe is an annular pipe, and its inner cavity is provided with several baffles for extending the gas flow path.

[0011] As a further description of the above technical solution: the condensation assembly also includes a cooling structure, which includes a water tank and a water pump for pumping the cooling medium in the water tank into the cooling pipe.

[0012] As a further description of the above technical solution: the side wall of the tower body is provided with a feed pipe, and the bottom of the reboiler is provided with a drain pipe.

[0013] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0014] 1. By wrapping the preheating pipe around the outer ring of the inlet pipe, the secondary steam flowing inside the inlet pipe conducts heat to the gas-phase mixture at the top of the tower through the pipe wall, thereby effectively reducing the temperature of the steam inside the inlet pipe, avoiding local overheating at the bottom of the tower, maintaining a stable gas-liquid balance, and thus improving separation efficiency.

[0015] 2. When the cooled steam enters the tower, it can more smoothly and efficiently vaporize the liquid at the bottom of the tower, making the heat transfer process in the tower more stable and thus improving the separation efficiency. While improving efficiency, it reduces the total heat required to drive the entire system, that is, it reduces the amount of steam generated by the reboiler. As the total heat provided by the reboiler decreases, the total amount of steam generated in the tower decreases accordingly, thereby reducing the total amount of gas that needs to be cooled escaping from the top of the tower. Therefore, the total heat that needs to be removed by the cooling water is reduced, thereby reducing the overall load on the condenser components. Attached Figure Description

[0016] Figure 1 A schematic diagram of the present invention is shown;

[0017] Legend:

[0018] 10. Tower body; 101. Feed pipe; 11. Gas outlet pipe; 12. Preheating pipe; 121. Baffle plate; 13. Gas delivery pipe; 14. Reflux pipe; 15. Liquid outlet pipe; 16. Reboiler; 161. Liquid drain pipe; 17. Gas inlet pipe; 18. Steam collection box; 19. Cooling pipe; 20. Water tank; 21. Water pump. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0020] Please see Figure 1 This utility model provides a technical solution: a regenerative condenser for a distillation column, including a column body 10. During the distillation process, the material enters the column through a feed pipe 101 located on the side wall of the column body 10. The bottom end of the column body 10 is connected to the inlet of a reboiler 16 through a liquid outlet pipe 15. The liquid at the bottom of the column (bottom liquid) flows into the reboiler 16 for heating. The reboiler 16 is connected to the lower part of the column body 10 through an air inlet pipe 17. The secondary steam generated after heating returns to the column body 10 through the air inlet pipe 17 to provide a heat source for the distillation process. The bottom of the reboiler 16 is also provided with a drain pipe 161 for discharging the bottom liquid.

[0021] Furthermore, a preheating pipe 12 is connected to the top of the tower body 10 via an outlet pipe 11. The gas phase mixture (relatively low temperature) coming out of the top of the tower first enters the preheating pipe 12, which is wrapped around the outer ring of the inlet pipe 17. Since the secondary steam entering the tower body 10 from the reboiler 16 is very hot, through this sleeve design, the secondary steam flowing in the inlet pipe 17 conducts heat through the pipe wall to the gas phase mixture at the top of the tower in the preheating pipe 12, thereby effectively reducing the temperature of the steam in the inlet pipe 17, avoiding local overheating at the bottom of the tower, maintaining a stable gas-liquid balance, and thus improving the separation efficiency.

[0022] By integrating the preheating pipe 12 with the air inlet pipe 17 into one unit, this integrated and compact design significantly reduces the equipment's footprint and space requirements compared to setting up a separate external heat exchanger. It also reduces the equipment's manufacturing and installation costs and the complexity of pipe connections, resulting in better economic efficiency.

[0023] Furthermore, in order to enhance the preheating effect, the preheating pipe 12 is designed as a ring pipe. Specifically, in order to prolong the residence time of the gas-phase mixture in the preheating pipe 12 and allow it to have a more thorough heat exchange with the outer wall of the high-temperature inlet pipe 17, a number of baffles 121 are provided in the inner cavity of the preheating pipe 12. These baffles 121 have a semi-ring structure, and adjacent baffles 121 are spaced apart and staggered along the airflow direction.

[0024] This layout forces the airflow to flow in an S-shape within the annular pipe, extending the flow path and residence time, thereby significantly improving the preheating efficiency. The gas, after being preheated by the preheating pipe 12, enters the condensing assembly through the gas delivery pipe 13 for condensation.

[0025] By setting semi-circular and staggered baffles 121 inside the preheating pipe 12, the flow path and residence time of the gas at the top of the tower in the pipe are effectively extended. This greatly enhances the heat exchange efficiency between the preheating pipe 12 and the inlet pipe 17, ensuring that heat energy is fully recovered and maximizing the energy-saving effect.

[0026] Furthermore, the condensation assembly includes a steam collection box 18, with a gas supply pipe 13 connected to the inlet of the steam collection box 18. A cooling pipe 19 is installed in the inner cavity of the steam collection box 18. The cooling pipe 19 is an S-shaped pipe. The design of the cooling pipe 19 increases the cooling surface area, enabling the gas entering the steam collection box 18 to exchange heat efficiently with the outer wall of the cooling pipe 19 and quickly condense into liquid.

[0027] The condenser assembly uses cooling tube 19, which increases the cooling area in a limited space, ensuring that the gas at the top of the column can be fully condensed, thereby making the entire distillation operation process more stable and reliable.

[0028] In order to provide a continuous cooling medium for the cooling pipe 19, a cooling structure is also provided, which includes a water tank 20 and a water pump 21.

[0029] The cooling water or other cooling medium in the water tank 20 is pressurized by the water pump 21 and pumped into one end of the cooling pipe 19. During the flow in the pipe, it absorbs the heat of the surrounding gas and then flows out from the other end, returning to the water tank 20 for recycling.

[0030] The liquid (condensate) formed by condensation in the steam collector 18 is returned to the column body 10 through the reflux pipe 14 as the reflux liquid for the distillation process, thereby ensuring the continuity and stability of the distillation operation. A portion of the condensate can also be taken out as the top product of the column (not shown in the figure).

[0031] When the cooled steam enters the tower body 10, it can more smoothly and efficiently vaporize the liquid at the bottom of the tower, making the heat transfer process in the tower more stable, thereby improving the separation efficiency. While improving efficiency, it reduces the total heat required to drive the entire system, that is, it reduces the amount of steam generated by the reboiler 16. As the total heat provided by the reboiler 16 decreases, the total amount of steam generated in the tower decreases accordingly, thereby reducing the total amount of gas that needs to be cooled escaping from the top of the tower. Therefore, the total heat that needs to be removed by the cooling water is reduced, thereby reducing the overall load on the condenser components.

[0032] Work steps:

[0033] The material enters the tower body 10 through the feed pipe 101. The liquid at the bottom of the tower enters the reboiler 16 for heating through the liquid outlet pipe 15. The high-temperature secondary steam generated is returned to the tower through the steam inlet pipe 17.

[0034] The gas mixture at the top of the tower enters the preheating pipe 12 through the outlet pipe 11. Under the guidance of the baffle 121, it is preheated by efficient heat exchange with the wall of the inlet pipe 17.

[0035] The preheated gas enters the steam collection box 18 through the gas delivery pipe 13 and condenses into liquid on the outer wall of the cooling pipe 19.

[0036] The condensate returns to the top of the tower body 10 via the return pipe 14, completing a full cycle.

[0037] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A regenerative condenser for a distillation column, comprising a column body (10), a reboiler (16) connected to the bottom of the column body (10) via a liquid outlet pipe (15), and a condensation assembly connected to the top of the column body (10), wherein the reboiler (16) sends steam into the column body (10) via an inlet pipe (17). Its features are: It also includes a preheating pipe (12), which is connected between the outlet pipe (11) at the top of the tower body (10) and the condensation assembly. The preheating pipe (12) is fitted around the outer periphery of the inlet pipe (17) in a heat exchange manner, and is used to preheat the gas flowing out of the tower body (10) by using the high-temperature steam entering the inlet pipe (17) from the reboiler (16).

2. The regenerative condenser for a distillation column according to claim 1, characterized in that: The condensation assembly includes a steam collection box (18), the bottom of which is connected to the preheating pipe (12) via a gas delivery pipe (13), and the bottom of which is connected to the tower body (10) via a return pipe (14).

3. The regenerative condenser for a distillation column according to claim 2, characterized in that: The steam collection box (18) is provided with a cooling pipe (19) for introducing cooling medium in its inner cavity. The cooling pipe (19) is an S-shaped pipe.

4. The regenerative condenser for a distillation column according to claim 1, characterized in that: The preheating pipe (12) is an annular pipe, and its inner cavity is provided with several baffles (121) for extending the gas flow path.

5. A regenerative condenser for a distillation column according to claim 4, characterized in that: The partition (121) is semi-circular, and adjacent partitions (121) are staggered along the gas flow direction.

6. A regenerative condenser for a distillation column according to claim 2, characterized in that: The condensation assembly also includes a cooling structure, which includes a water tank (20) and a water pump (21) for pumping the cooling medium in the water tank (20) into the cooling pipe (19).

7. A regenerative condenser for a distillation column according to claim 1, characterized in that: The side wall of the tower body (10) is provided with a feed pipe (101), and the bottom of the reboiler (16) is provided with a drain pipe (161).

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