Rectifying tower coupling heat pump molecular sieve membrane dehydration equipment

Abstract

The utility model discloses rectifying tower coupling heat pump molecular sieve membrane dehydration equipment, which belongs to the technical field of dehydration equipment and comprises a rectifying tower, a first reboiler, a second reboiler and a third reboiler. A heat pump and a cut-off valve are sequentially arranged on a pipeline from the rectifying tower to the molecular sieve membrane equipment, at the beginning stage, the cut-off valve of the heat pump to the molecular sieve membrane is closed, steam is introduced into the first reboiler to vaporize a liquid-phase raw material, and a gas phase at the top of the rectifying tower is heated and pressurized by the heat pump and then enters the third reboiler; condensing into a liquid phase after exchanging heat with the raw material discharged from the first reboiler, and then circulating into the rectifying tower; after the tower top gas phase is qualified, a stop valve is opened, a part of tower top gas phase solvent is dehydrated by molecular sieve membrane equipment, then enters a second reboiler, is condensed and then is cooled out of the device through a product cooler, and compared with a traditional process, the process has the advantage that the steam introduction amount can be greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of dehydration equipment, in particular to a distillation tower coupled heat pump molecular sieve membrane dehydration equipment. Background Art

[0002] At present, the traditional distillation tower coupled with molecular sieve membrane dehydration adopts the method of azeotropically extracting qualified gaseous solvent from the distillation tower after reflux control and directly entering the molecular sieve membrane for deep dehydration, or the gaseous solvent at the top of the tower is condensed and enters the top reflux tank, and is pumped into the molecular sieve membrane by the top reflux pump for vaporization and dehydration. During this process, the distillation tower needs to continuously use steam to vaporize the liquid phase solvent and the reflux liquid phase solvent to ensure the stable extraction of the gas phase solvent from the distillation tower. The dehydrated gas phase solvent product is heat-exchanged with the liquid phase raw material and then cooled. Therefore, the steam consumption of the front-end distillation tower is very large, the energy consumption is very high, and the operating cost of the entire coupled process is also high. Utility Model Content

[0003] The purpose of the utility model is to solve the problems mentioned in the above background technology that the steam consumption of the front-end distillation tower is large, the energy consumption is high, and the operating cost of the entire coupled process is also high.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A distillation tower coupled heat pump molecular sieve membrane dehydration device, comprising a distillation tower and a No. 1 reboiler, a No. 2 reboiler and a No. 3 reboiler, the upper end of the distillation tower being connected to a molecular sieve membrane device via a pipeline, a heat pump and a shut-off valve being sequentially provided on the pipeline from the distillation tower to the molecular sieve membrane device, the molecular sieve membrane device being communicated with a side inlet of the No. 2 reboiler via a pipeline, a tee being connected to the pipeline between the heat pump and the shut-off valve, the tee being communicated with a side inlet of the No. 3 reboiler via a pipeline, The boiler side outlet is connected to a tower top reflux tank through a pipeline, and the tower top reflux tank is connected to a tower top reflux pump through a pipeline. The tower top reflux pump is connected to the top of the distillation tower through a pipeline, and the lower end of the distillation tower is connected to the bottom inlet of the No. 1 reboiler through a pipeline. The pipeline from the distillation tower to the No. 1 reboiler is connected to a bottom pump, and the top outlet of the No. 1 reboiler is connected to the top inlets of the No. 2 reboiler and the No. 3 reboiler, and the bottom outlets of the No. 2 reboiler and the No. 3 reboiler are connected to the bottom of the distillation tower through a pipeline.

[0006] Preferably, a permeate condenser is provided on one side of the molecular sieve membrane device, and the molecular sieve membrane device is connected to the top inlet of the permeate condenser through a pipeline.

[0007] Preferably, a waste pipe is connected to the bottom of the permeate condenser.

[0008] Preferably, the bottom side of the permeate condenser is connected to a vacuum pump via a pipeline.

[0009] Preferably, a side inlet and a side outlet are provided on the side of the permeate condenser.

[0010] Preferably, a product cooler is provided on one side of the No. 2 reboiler, the side outlet of the No. 2 reboiler is connected to the top inlet of the product cooler through a pipeline, and the bottom end of the product cooler is connected to the product outlet.

[0011] Preferably, the product cooler is provided with a side inlet and a side outlet.

[0012] Preferably, the product outlet of the product cooler is connected to a storage tank via a pipeline, and the bottom end of the storage tank is connected to an outlet.

[0013] Preferably, the bottom outlet of the storage tank is connected to a three-way valve, and the three-way valve is connected to the bottom of the distillation tower through a connecting pipe.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] By providing a coupling technology for the distillation tower, heat pump, and molecular sieve membrane dehydration process, in the initial stage, the shut-off valve of the heat pump to the molecular sieve membrane is closed, and steam is introduced into the No. 1 reboiler to vaporize the liquid raw material. The top gas phase of the distillation tower is heated and pressurized by the heat pump and then sent to the No. 3 reboiler, and after heat exchange with the raw material coming out of the No. 1 reboiler, it is condensed into a liquid phase and recycled to the distillation tower; after the top gas phase is qualified, the shut-off valve is opened, and part of the top gas phase solvent is dehydrated by the molecular sieve membrane equipment and sent to the No. 2 reboiler, condensed and then cooled out of the device through the product cooler. Compared with the traditional process, this process can greatly reduce the amount of steam introduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0018] Explanation of figure numbers: 1. Distillation tower; 2. Heat pump; 3. Reboiler No. 3; 4. Top reflux tank; 5. Top reflux pump; 6. Molecular sieve membrane equipment; 7. Reboiler No. 2; 8. Reboiler No. 1; 9. Product cooler; 10. Bottom pump; 11. Permeate condenser; 12. Vacuum pump; 13. Shut-off valve; 14. Storage tank; 15. Three-way valve. DETAILED DESCRIPTION

[0019] The present invention is described in further detail below with reference to the accompanying drawings.

[0020] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention as defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0021] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "transverse", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate directions or positions are based on the directions or positional relationships shown in the accompanying drawings, which are merely simplified descriptions for the convenience of describing the present invention, and do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the above terms should not be understood as limitations on the present invention.

[0022] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the elements may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0023] See also Figure 1, a distillation tower coupled heat pump molecular sieve membrane dehydration equipment, comprising a distillation tower 1 and a No. 1 reboiler 8, a No. 2 reboiler 7 and a No. 3 reboiler 3, the upper end of the distillation tower 1 is connected to a molecular sieve membrane device 6 through a pipeline, a heat pump 2 and a shut-off valve 13 are sequentially provided on the pipeline from the distillation tower 1 to the molecular sieve membrane device 6, the molecular sieve membrane device 6 is connected to the side inlet of the No. 2 reboiler 7 through a pipeline, a product cooler 9 is provided on one side of the No. 2 reboiler 7, the side outlet of the No. 2 reboiler 7 is connected to the top inlet of the product cooler 9 through a pipeline, the bottom end of the product cooler 9 is connected to the product outlet, the product cooler 9 is provided with a side inlet and a side outlet, cooling water enters from the side inlet of the product cooler 9 and then flows out from the side outlet, a tee is connected to the pipeline between the heat pump 2 and the shut-off valve 13, the tee is connected to the side inlet of the No. 3 reboiler 3 through a pipeline The top of the distillation tower 1 is connected to the bottom inlet of the No. 1 reboiler 8 through a pipeline. The bottom pump 10 is connected to the pipeline from the distillation tower 1 to the No. 1 reboiler 8. The top outlet of the No. 1 reboiler 8 is connected to the top inlet of the No. 2 reboiler 7 and the No. 3 reboiler 3. The No. 1 reboiler 8 is provided with a side inlet and a side outlet. Steam is introduced into the No. 1 reboiler 8 from the side inlet to vaporize the liquid raw material, and the steam condensate flows out from the side outlet of the No. 1 reboiler 8. The bottom outlet of the No. 2 reboiler 7 and the No. 3 reboiler 3 is connected to the bottom of the distillation tower 1 through a pipeline.

[0024] A permeate condenser 11 is provided on one side of the molecular sieve membrane device 6. The molecular sieve membrane device 6 is connected to the top inlet of the permeate condenser 11 through a pipeline. The bottom of the permeate condenser 11 is connected to a waste pipe. The bottom side of the permeate condenser 11 is connected to a vacuum pump 12 through a pipeline. The side of the permeate condenser 11 is provided with a side inlet and a side outlet. Cooling water enters the permeate condenser 11 from the side inlet and then flows out from the side outlet.

[0025] The product outlet of the product cooler 9 is connected to a storage tank 14 through a pipeline. The product enters the storage tank 14 for temporary storage. The bottom end of the storage tank 14 is connected to an outlet. The bottom outlet of the storage tank 14 is connected to a three-way valve 15. The three-way valve 15 is connected to the bottom of the distillation tower 1 through a connecting pipe. A delivery pump is connected to the pipeline from the three-way valve 15 to the bottom of the distillation tower 1. The delivery pump is not shown in the prior art figure. After the product is detected to be unqualified, the product in the storage tank 14 is delivered to the distillation tower 1 through the delivery pump.

[0026] When in use, first, keep the shut-off valve 13 in a closed state, the liquid raw material enters the bottom of the distillation tower 1, the liquid phase of the bottom of the distillation tower 1 is pressurized by the bottom pump 10 and enters the No. 1 reboiler 8, steam is introduced into the No. 1 reboiler 8 from the side inlet to vaporize the liquid raw material, and the steam condensate flows out from the side outlet of the No. 1 reboiler 8. Then, the top gas phase of the distillation tower 1 is heated and pressurized by the heat pump 2 and goes to the No. 3 reboiler 3, and is heat-exchanged with the raw material coming out of the No. 1 reboiler 8 and then cooled. It condenses into liquid phase, enters the top reflux tank 4 after condensation, and is pressurized by the top reflux pump 5 and refluxes to the distillation tower 1. After that, the shut-off valve 13 is opened, and part of the qualified gas phase at the top of the tower is heated and pressurized by the heat pump 2 and goes to the molecular sieve membrane device 6, dehydrated and goes to the No. 2 reboiler 7, condensed and goes to the product cooler 9 for cooling and then exits the device. Finally, the permeated gas phase of the molecular sieve membrane device 6 goes to the permeate condenser 11, the condensed permeate is used for wastewater treatment, and the non-condensable tail gas is extracted by the vacuum pump 12.

[0027] Those skilled in the art will appreciate that the embodiments of the present invention described above and shown in the accompanying drawings are intended only as examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and illustrated in the embodiments. Any variations or modifications may be made to the embodiments of the present invention without departing from the principles described.

Claims

1. A distillation tower coupled heat pump molecular sieve membrane dehydration equipment, characterized in that: The invention comprises a distillation tower (1) and a No. 1 reboiler (8), a No. 2 reboiler (7) and a No. 3 reboiler (3), wherein the upper end of the distillation tower (1) is connected to a molecular sieve membrane device (6) through a pipeline, a heat pump (2) and a shut-off valve (13) are sequentially arranged on the pipeline from the distillation tower (1) to the molecular sieve membrane device (6), the molecular sieve membrane device (6) is connected to the side inlet of the No. 2 reboiler (7) through a pipeline, a tee is connected to the pipeline between the heat pump (2) and the shut-off valve (13), the tee is connected to the side inlet of the No. 3 reboiler (3) through a pipeline, and the side outlet of the No. 3 reboiler (3) is connected to the side outlet of the No. 3 reboiler (3) through a pipe. The top reflux tank (4) is connected to the top reflux tank (4) through a pipeline, and the top reflux pump (5) is connected to the top of the distillation tower (1) through a pipeline. The top reflux pump (5) is connected to the top of the distillation tower (1) through a pipeline. The lower end of the distillation tower (1) is connected to the bottom inlet of the No. 1 reboiler (8) through a pipeline. The pipeline from the distillation tower (1) to the No. 1 reboiler (8) is connected to a bottom pump (10). The top outlet of the No. 1 reboiler (8) is connected to the top inlets of the No. 2 reboiler (7) and the No. 3 reboiler (3). The bottom outlets of the No. 2 reboiler (7) and the No. 3 reboiler (3) are connected to the bottom of the distillation tower (1) through a pipeline.

2. The distillation tower coupled heat pump molecular sieve membrane dehydration equipment according to claim 1, characterized in that: A permeate condenser (11) is provided on one side of the molecular sieve membrane device (6), and the molecular sieve membrane device (6) is connected to the top inlet of the permeate condenser (11) through a pipeline.

3. The distillation tower coupled heat pump molecular sieve membrane dehydration equipment according to claim 2, characterized in that: The bottom of the permeate condenser (11) is connected to a waste pipe.

4. The distillation tower coupled heat pump molecular sieve membrane dehydration equipment according to claim 3, characterized in that: The bottom side of the permeate condenser (11) is connected to a vacuum pump (12) via a pipeline.

5. The distillation tower coupled heat pump molecular sieve membrane dehydration equipment according to claim 4, characterized in that: A side inlet and a side outlet are provided on the side of the permeate condenser (11).

6. The distillation tower coupled heat pump molecular sieve membrane dehydration equipment according to claim 1, characterized in that: A product cooler (9) is provided on one side of the No. 2 reboiler (7), a side outlet of the No. 2 reboiler (7) is connected to a top inlet of the product cooler (9) through a pipeline, and a product outlet is connected to the bottom end of the product cooler (9).

7. The distillation tower coupled heat pump molecular sieve membrane dehydration equipment according to claim 6, characterized in that: The product cooler (9) is provided with a side inlet and a side outlet.

8. The distillation tower coupled heat pump molecular sieve membrane dehydration equipment according to claim 7, characterized in that: The product outlet of the product cooler (9) is connected to a storage tank (14) via a pipeline, and the bottom end of the storage tank (14) is connected to an outlet.

9. The distillation tower coupled heat pump molecular sieve membrane dehydration equipment according to claim 8, characterized in that: The bottom outlet of the storage tank (14) is connected to a three-way valve (15), and the three-way valve (15) is connected to the bottom of the distillation tower (1) through a connecting pipe.

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