Full-partition plate thermal coupling rectification system

Abstract

The utility model belongs to the technical field of rectification, and particularly relates to a full-partition thermal coupling rectification system which comprises a rectification tower and a thermal coupling reboiler, a partition is arranged in the rectification tower, and the interior of the rectification tower is divided into a first-effect rectification tower and a second-effect rectification tower by the partition. A first-effect liquid outlet of the first-effect rectifying tower is connected with a reboiling liquid phase inlet of the thermal coupling reboiler and a second-effect liquid phase inlet of the second-effect rectifying tower through pipelines, and a reboiling gas phase outlet of the thermal coupling reboiler is connected with a first-effect gas phase inlet of the first-effect rectifying tower through a pipeline; and a second-effect gas phase outlet of the second-effect rectifying tower is connected with a reboiling heating gas inlet of the thermal coupling reboiler through a pipeline. On one hand, the heat coupling process in the rectifying tower is realized, the areas of the reboiler and the condenser are reduced, and on the other hand, the quantity of the rectifying tower is reduced, so that the equipment investment cost is reduced, and the energy-saving effect of the system is improved.

Description

Technical Field

[0001] The utility model relates to a full-partition thermal coupling distillation system, belonging to the technical field of distillation. Background Art

[0002] Distillation is a separation process that utilizes the varying volatility of components in a mixture. It requires distillation towers as equipment. To improve heat utilization, multiple-effect distillation systems are often used in existing material separation operations. Multi-effect distillation follows the same principle as multiple-effect evaporation: it employs a series of distillation towers with decreasing pressures. The overhead vapor from the preceding tower serves as the heating medium for the reboiler in the succeeding tower. This eliminates the need for external heating and cooling media for intermediate distillation units, except for the two end towers. However, multiple-effect distillation technology involves a relatively large number of distillation towers. For example, a double-effect distillation process requires two distillation towers, while a triple-effect distillation process requires three. Each additional tower, in addition to requiring additional plant space, increases equipment costs. Furthermore, existing multiple-effect distillation processes require large, costly, and larger thermally coupled reboilers, increasing the equipment footprint. Utility Model Content

[0003] The utility model aims at solving the above-mentioned technical problems in the prior art and provides a full-partition thermally coupled distillation system.

[0004] The technical solution of the utility model to solve the above technical problems is as follows:

[0005] A full-partition thermally coupled distillation system comprises a distillation tower and a thermally coupled reboiler, wherein a partition is provided in the distillation tower, and the partition divides the interior of the distillation tower into a first-effect distillation tower and a second-effect distillation tower, the first-effect liquid outlet of the first-effect distillation tower is connected to the reboiled liquid phase inlet of the thermally coupled reboiler and the second-effect liquid phase inlet of the second-effect distillation tower through a pipeline, the reboiled gas phase outlet of the thermally coupled reboiler is connected to the first-effect gas phase inlet of the first-effect distillation tower through a pipeline, and the second-effect gas phase outlet of the second-effect distillation tower is connected to the reboiled heating gas inlet of the thermally coupled reboiler through a pipeline.

[0006] The beneficial effects of the present invention are as follows: the present invention designs a distillation tower with a full partition structure, thereby dividing the distillation tower into a single-effect distillation tower and a double-effect distillation tower. This tower structure, on the one hand, can realize the heat coupling process inside the distillation tower, reducing the area of ​​the reboiler and condenser, and on the other hand, can reduce the number of distillation towers. The original double-effect distillation process requires two sets of independent distillation towers to be realized, while the distillation tower structure of the present invention can be realized with a single set of distillation towers, merging the two sets of distillation towers into one set of distillation towers, thereby reducing the equipment investment cost and improving the energy-saving effect of the system. The structure of the present invention can be applied to multi-effect distillation processes, such as double-effect, triple-effect, quadruple-effect, and quintuple-effect distillation.

[0007] On the basis of the above technical solution, the present invention can also make the following improvements:

[0008] Furthermore, the first-effect gas phase outlet of the first-effect distillation tower is connected to the first-effect condensation gas phase inlet of the first-effect condenser through a pipeline, and the first-effect condensation liquid phase outlet of the first-effect condenser is connected to the first-effect reflux tank through a pipeline.

[0009] Furthermore, a first-effect tower top liquid phase inlet is provided at the top of the first-effect distillation tower, and the liquid outlet of the first-effect reflux tank is extracted through a pipeline and connected to the first-effect tower top liquid phase inlet of the first-effect distillation tower.

[0010] Furthermore, the first-stage condensation gas phase outlet of the first-stage condenser is connected to the second-stage condensation gas phase inlet of the second-stage condenser through a pipeline, and the second-stage condensation liquid phase outlet of the second-stage condenser is connected to the first-effect reflux tank through a pipeline.

[0011] Furthermore, it also includes a second-effect reboiler, the reboiled steam outlet of the second-effect reboiler is connected to the second-effect gas phase inlet of the second-effect distillation tower through a pipeline, and the second-effect liquid outlet of the second-effect distillation tower kettle is connected to the reboiled liquid inlet of the second-effect reboiler through a pipeline and is produced through a pipeline.

[0012] Furthermore, it also includes a second-effect reflux tank, the reboiled condensed liquid outlet of the thermally coupled reboiler is connected to the liquid inlet of the second-effect reflux tank through a pipeline, and the liquid outlet of the second-effect reflux tank is extracted through a pipeline and connected to the second-effect tower top liquid phase inlet of the second-effect distillation tower.

[0013] Furthermore, a fourth pump is provided on the pipeline connected to the second-effect liquid outlet of the second-effect distillation tower, and a third reflux pump is provided on the pipeline connected to the liquid outlet of the second-effect reflux tank.

[0014] Furthermore, a first pump is provided on the pipeline connected to the first-effect liquid outlet of the first-effect distillation tower, and a second reflux pump is provided on the pipeline connected to the liquid outlet of the first-effect reflux tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1This is a full-partition thermally coupled distillation system of the utility model.

[0016] The reference numerals are recorded as follows: 1. distillation tower; 11. first-effect distillation tower; 1101. first-effect liquid outlet; 1102. first-effect raw material inlet; 1103. first-effect gas phase inlet; 1104. first-effect gas phase outlet; 1105. first-effect tower top liquid phase inlet; 12. second-effect distillation tower; 1201. second-effect liquid outlet; 1202. second-effect gas phase inlet; 1203. second-effect liquid phase inlet; 1204. second-effect gas phase outlet; 1205. second-effect tower top liquid phase inlet; 13. partition; 2. thermally coupled reboiler; 21. reboiled liquid phase inlet; 22. reboiled gas phase outlet; 23. reboiled heating gas inlet; 24. Reboiled condensate liquid outlet; 3. First-stage condenser; 31. First-stage condensed gas inlet; 32. First-stage condensed liquid outlet; 33. First-stage condensed gas outlet; 4. Second-stage condenser; 41. Second-stage condensed gas inlet; 42. Second-stage condensed liquid outlet; 43. Second-stage condensed gas outlet; 5. First-effect reflux tank; 6. Second-effect reflux tank; 7. Second-effect reboiler; 71. Reboiled steam outlet; 72. Reboiled liquid inlet; 8. Pipeline one; 9. Pump one; 10. Pipeline two; 14. Reflux pump two; 15. Pipeline three; 16. Pipeline four; 17. Pump four; 18. Pipeline five; 19. Reflux pump three. DETAILED DESCRIPTION

[0017] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0018] See also Figure 1 A full-partition thermally coupled distillation system includes a distillation tower 1, a thermally coupled reboiler 2, a primary condenser 3, a secondary condenser 4, a first-effect reflux tank 5, a second-effect reflux tank 6 and a second-effect reboiler 7.

[0019] The thermally coupled reboiler 2 is provided with a reboiled liquid phase inlet 21 , a reboiled gas phase outlet 22 , a reboiled heated gas inlet 23 and a reboiled condensed liquid outlet 24 .

[0020] A partition 13 is provided in the distillation tower 1, and the partition 13 divides the interior of the distillation tower 1 into a first-effect distillation tower 11 and a second-effect distillation tower 12. The bottom of the first-effect distillation tower 11 is provided with a first-effect liquid outlet 1101, the middle of the first-effect distillation tower 11 is provided with a first-effect raw material inlet 1102 and a first-effect gas phase inlet 1103, the top of the first-effect distillation tower 11 is provided with a first-effect gas phase outlet 1104 and a first-effect tower top liquid phase inlet 1105, the bottom of the second-effect distillation tower 12 is provided with a second-effect liquid outlet 1201, the middle of the second-effect distillation tower 12 is provided with a second-effect gas phase inlet 1202 and a second-effect liquid phase inlet 1203, and the top of the second-effect distillation tower 12 is provided with a second-effect gas phase outlet 1204 and a second-effect tower top liquid phase inlet 1205.

[0021] The first-effect liquid outlet 1101 of the first-effect distillation tower 11 is connected to the reboiled liquid phase inlet 21 of the thermally coupled reboiler 2 and the second-effect liquid phase inlet 1203 of the second-effect distillation tower 12 through a pipeline 8. A pump 9 is provided on the pipeline 8. The material in the bottom of the first-effect distillation tower 11 circulates between the bottom of the first-effect distillation tower 11 and the thermally coupled reboiler 2 through the pump 9. The reboiled gas phase outlet 22 of the thermally coupled reboiler 2 is connected to the first-effect gas phase inlet 1103 of the first-effect distillation tower 11 through a pipeline. The second-effect gas phase outlet 1204 of the second-effect distillation tower 12 is connected to the reboiled heating gas inlet 23 of the thermally coupled reboiler 2 through a pipeline to exchange heat with the thermally coupled reboiler 2.

[0022] The first-stage condenser 3 is provided with a first-stage condensed gas phase inlet 31, a first-stage condensed liquid phase outlet 32 ​​and a first-stage condensed gas phase outlet 33. The first-stage gas phase outlet 1104 of the first-effect distillation tower 11 is connected to the first-stage condensed gas phase inlet 31 of the first-stage condenser 3 through a pipeline, and the first-stage condensed liquid phase outlet 32 ​​of the first-stage condenser 3 is connected to the first-effect reflux tank 5 through a pipeline.

[0023] The secondary condenser 4 has a secondary condensation gas phase inlet 41, a secondary condensation liquid phase outlet 42 and a secondary condensation gas phase outlet 43. The primary condensation gas phase outlet 33 of the primary condenser 3 is connected to the secondary condensation gas phase inlet 41 of the secondary condenser 4 through a pipeline, and the secondary condensation liquid phase outlet 42 of the secondary condenser 4 is connected to the first-effect reflux tank 5 through a pipeline. After passing through the secondary condenser 4, there is still some uncondensed top gas or non-condensed steam, which is discharged from the secondary condensation gas phase outlet 43 of the secondary condenser 4.

[0024] The first-effect reflux tank 5 is provided with a liquid inlet and a liquid outlet. The first-stage condensed liquid phase outlet 32 ​​and the second-stage condensed liquid phase outlet 42 are both connected to the liquid inlet of the first-effect reflux tank 5. The liquid outlet of the first-effect reflux tank 5 is extracted through pipeline 2 10 and connected to the first-effect tower top liquid phase inlet 1105 of the first-effect distillation tower 11. A reflux pump 2 14 is provided on the pipeline 2 10. The first-effect reflux tank 5 is forced to reflux and extract through the reflux pump 2 14.

[0025] It also includes a second-effect reboiler 7, which is provided with a reboiled steam outlet 71 and a reboiled liquid inlet 72. The reboiled steam outlet 71 of the second-effect reboiler 7 is connected to the second-effect gas phase inlet 1202 of the second-effect distillation tower 12 through a pipeline, and the second-effect liquid outlet 1201 of the bottom of the second-effect distillation tower 12 is connected to the reboiled liquid inlet 72 of the second-effect reboiler 7 through a pipeline three 15 and is produced through a pipeline four 16. A pump four 17 is provided on the pipeline four 16. Part of the material in the bottom of the second-effect distillation tower 12 enters the second-effect reboiler 7 through the pipeline three 15 to be heated and vaporized, and the other part is produced as wastewater without product through the pump four 17 on the pipeline four 16.

[0026] It also includes a second-effect reflux tank 6, which is provided with a liquid inlet and a liquid outlet. The reboiled condensed liquid outlet 24 of the thermally coupled reboiler 2 is connected to the liquid inlet of the second-effect reflux tank 6 through a pipeline. The liquid outlet of the second-effect reflux tank 6 is extracted through a pipeline five 18 and connected to the second-effect tower top liquid phase inlet 1205 of the second-effect distillation tower 12. A reflux pump three 19 is provided on the pipeline five 18, and the second-effect reflux tank 6 is forced to reflux and extract through the reflux pump three 19.

[0027] Taking ethanol double-effect distillation as an example, the embodiment of the present invention adopts the distillation process of the above-mentioned full-baffle thermal coupling distillation system, which specifically includes the following steps:

[0028] (1) The ethanol aqueous solution to be treated (feed rate 21 t / h, ethanol content 55%, water content 45%) enters the bottom of the first-effect distillation tower 11 from the first-effect raw material inlet 1102. The first-effect distillation tower 11 operates under negative pressure conditions, which is 40 kPaA. The material in the bottom of the first-effect distillation tower 11 is circulated between the bottom of the first-effect distillation tower 11 and the thermally coupled reboiler 2 through pump 9;

[0029] (2) The gas phase (about 16 t / h in total, with an ethanol content of 92.6% and a water content of 7.4%) generated by the heating of the first-effect distillation tower 11 is condensed and cooled in the first-stage condenser 3 and the second-stage condenser 4 in sequence. The condensate generated by the cooling of the first-stage condenser 3 and the second-stage condenser 4 enters the first-effect reflux tank 5;

[0030] (3) The material in the first-effect reflux tank 5 is forced to reflux to the first-effect distillation tower 11 and the product is produced by the reflux pump 2 14. The reflux rate is 9.6 t / h, the production rate is 6.4 t / h, and a qualified 95 vol % ethanol product (wherein the ethanol mass content is 92.6%) is produced at the top of the tower;

[0031] (4) The operating pressure of the second-effect distillation tower 12 is atmospheric pressure, and steam is used to achieve heating through the second-effect reboiler 7. The gas phase generated by the heating of the second-effect distillation tower 12 is used as a heat source to enter the thermal coupling reboiler 2 for heat exchange. The gas phase volume is 18.2 t / h. The condensate generated by the heat exchange of the thermal coupling reboiler 2 enters the second-effect reflux tank 6. The material in the second-effect reflux tank 6 is forced to reflux to the second-effect distillation tower 12 and the product is produced by the reflux pump 3 19. The reflux volume is 12.2 t / h and the production volume is 6 t / h. The top of the second-effect distillation tower also produces a qualified 95 vol% ethanol product;

[0032] (5) Part of the material at the bottom of the second-effect distillation tower 12 enters the second-effect reboiler 7 for heating and vaporization, and part of it is extracted as wastewater without ethanol through pump 4 17, with an extraction rate of 8.6 t / h.

[0033] The working principle of the full-partition thermally coupled distillation system of the present invention is further explained below:

[0034] Taking countercurrent double-effect distillation as an example, the material to be processed is continuously passed into the first-effect distillation tower 11, and the top gas phase of the second-effect distillation tower 12 is used to heat the material in the first-effect distillation tower 11 through the thermal coupling reboiler 2. The fresh heat source heats the second-effect distillation tower 12 through a conventional reboiler (i.e., the second-effect reboiler 7). At the same time, the material in the first-effect distillation tower 11 passes through the thermal coupling reboiler 2 as a cold source for the top gas phase of the second-effect distillation tower 12, and the top gas phase of the first-effect distillation tower 11 is cooled by a conventional cooling medium, thereby realizing the coupled utilization of heat, reducing the consumption of steam and circulating water during operation, and achieving the purpose of reducing the energy consumption of equipment operation.

[0035] Under the double-effect distillation process conditions, a partition 13 is set in the middle of the full-partition thermal coupling distillation tower to divide the entire distillation tower 1 into two from the inside. The left and right sides serve as the first-effect distillation tower 11 and the second-effect distillation tower 12 respectively, and the operating pressure and operating temperature between the two effects are different. The specific double-effect distillation operation process is consistent with the conventional double-effect distillation process. The difference is that the middle partition 13 of the full-partition thermal coupling distillation tower can realize the coupled utilization of heat, that is, the operating temperature of the whole tower of the second-effect distillation tower 12 on the right is higher than that of the first-effect distillation tower 11 on the left. Therefore, heat can be transferred through the partition 13. A part of the heat required for the normal operation of the first-effect distillation tower 11 on the left is transferred through the middle partition 13, and the remaining part is then transferred from the top gas phase heat of the second-effect distillation tower 12 to the bottom liquid phase of the first-effect distillation tower 11 through the thermal coupling reboiler 2. At the same time, part of the cooling capacity required for the normal operation of the second-effect distillation tower 12 on the right is transferred through the middle partition 13, and the remaining part is transferred from the bottom liquid phase cooling capacity of the first-effect distillation tower 11 to the top gas phase of the second-effect distillation tower 12 through the thermal coupling reboiler 2.

[0036] The above process can, on the one hand, reduce the heat exchange amount of the heat-coupled reboiler 2, thereby reducing its heat exchange area, and on the other hand, can merge two sets of double-effect distillation towers with relatively small diameters into a full-partition heat-coupled distillation tower with a relatively large diameter (keeping the cross-sectional area of ​​the full-partition heat-coupled distillation tower consistent with the cross-sectional area of ​​the double-effect distillation tower. As a preferred embodiment of the present invention, the diameter of the first-effect distillation tower in this embodiment is 2.2m, and the diameter of the second-effect distillation tower is 2m. After being merged into a full-partition heat-coupled distillation tower, the diameter is 3m. The cross-sectional areas of the first-effect distillation tower and the second-effect distillation tower after partitioning are 54% and 46% respectively), thereby effectively reducing the equipment investment cost. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A full-partition thermally coupled distillation system, characterized in that: The invention comprises a distillation tower (1) and a thermally coupled reboiler (2), wherein a partition (13) is provided in the distillation tower (1), and the partition (13) divides the interior of the distillation tower (1) into a first-effect distillation tower (11) and a second-effect distillation tower (12), wherein the first-effect liquid outlet (1101) of the first-effect distillation tower (11) is connected to the reboiled liquid phase inlet (21) of the thermally coupled reboiler (2) and the second-effect liquid phase inlet (1203) of the second-effect distillation tower (12) through a pipeline, the reboiled gas phase outlet (22) of the thermally coupled reboiler (2) is connected to the first-effect gas phase inlet (1103) of the first-effect distillation tower (11) through a pipeline, and the second-effect gas phase outlet (1204) of the second-effect distillation tower (12) is connected to the reboiled heating gas inlet (23) of the thermally coupled reboiler (2) through a pipeline.

2. The full-partition thermally coupled distillation system according to claim 1, characterized in that: The first-effect gas phase outlet (1104) of the first-effect distillation tower (11) is connected to the first-effect condensation gas phase inlet (31) of the first-effect condenser (3) through a pipeline, and the first-effect condensation liquid phase outlet (32) of the first-effect condenser (3) is connected to the first-effect reflux tank (5) through a pipeline.

3. The full-partition thermally coupled distillation system according to claim 2, characterized in that: The top of the first-effect distillation tower (11) is provided with a first-effect tower top liquid phase inlet (1105), and the liquid outlet of the first-effect reflux tank (5) is extracted through a pipeline and connected to the first-effect tower top liquid phase inlet (1105) of the first-effect distillation tower (11).

4. The full-partition thermally coupled distillation system according to claim 3, characterized in that: The primary condensed gas phase outlet (33) of the primary condenser (3) is connected to the secondary condensed gas phase inlet (41) of the secondary condenser (4) through a pipeline, and the secondary condensed liquid phase outlet (42) of the secondary condenser (4) is connected to the first-effect reflux tank (5) through a pipeline.

5. The full-partition thermally coupled distillation system according to any one of claims 1 to 4, characterized in that: The second-effect distillation tower (12) further comprises a second-effect reboiler (7), wherein the reboiled steam outlet (71) of the second-effect reboiler (7) is connected to the second-effect gas phase inlet (1202) of the second-effect distillation tower (12) via a pipeline, and the second-effect liquid outlet (1201) of the bottom of the second-effect distillation tower (12) is connected to the reboiled liquid inlet (72) of the second-effect reboiler (7) via a pipeline and is extracted via the pipeline.

6. The full-partition thermally coupled distillation system according to claim 5, characterized in that: It also includes a second-effect reflux tank (6), the reboiled condensed liquid outlet (24) of the thermally coupled reboiler (2) is connected to the liquid inlet of the second-effect reflux tank (6) through a pipeline, and the liquid outlet of the second-effect reflux tank (6) is extracted through a pipeline and connected to the second-effect tower top liquid phase inlet (1205) of the second-effect distillation tower (12).

7. The full-partition thermally coupled distillation system according to claim 6, characterized in that: A fourth pump (17) is provided on the pipeline connected to the second-effect liquid outlet (1201) of the second-effect distillation tower (12), and a third reflux pump (19) is provided on the pipeline connected to the liquid outlet of the second-effect reflux tank (6).

8. The full-partition thermally coupled distillation system according to any one of claims 2 to 4, characterized in that: A pump 1 (9) is provided on the pipeline connected to the first-effect liquid outlet (1101) of the first-effect distillation tower (11), and a reflux pump 2 (14) is provided on the pipeline connected to the liquid outlet of the first-effect reflux tank (5).

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