Energy-saving vacuum flash evaporation organic solvent recovery device

Abstract

The utility model relates to production link and residual liquid organic solvent recovery technical field, concretely relates to energy -conserving vacuum flash evaporation organic solvent recovery device. Including the flash evaporation tower, the lower end fixed communication of flash evaporation tower has the liquid outlet pipeline, the lower end fixed communication of flash evaporation tower has the circulation pipeline, installs the circulating heater on circulation pipeline, the upper end fixed communication of flash evaporation tower has the gas phase pipeline, installs the air -ejector pump on the gas phase pipeline, and the shell side of gas phase pipeline and the advection heat exchanger are communicated, and the material that discharged from the shell side of advection heat exchanger enters the storage tank after the terminal cooler, the upper portion in -flash evaporation tower fixedly has atomizing shower nozzle, and the liquid inlet pipeline is communicated with atomizing shower nozzle, and installs the booster pump and main heater on the liquid inlet pipeline, and the tube side of advection heat exchanger is communicated with liquid inlet pipeline. The utility model's flash evaporation tower negative pressure environment reduces solvent thermal decomposition risk, and air -ejector pump, circulating pump, booster pump linkage, realize pressure, temperature self -balancing, gas phase pipeline whole course negative pressure delivery solvent vapour, and prevent leakage.

Description

Technical Field

[0001] This utility model relates to the field of organic solvent recovery technology, specifically to an energy-saving vacuum flash evaporation organic solvent recovery device. Background Technology

[0002] In industries such as chemical, pharmaceutical, and coating, commonly used solvents include methanol, ethanol, benzene, acetone, ammonia, isopropanol, acetonitrile, dichloromethane, and ethyl acetate. Efficient recovery of organic solvents is crucial for reducing production costs and environmental pollution. Traditional solvent recovery processes often employ atmospheric distillation or single-stage flash evaporation, which suffer from high energy consumption, low thermal efficiency, and incomplete recovery of residual solvents. Especially for boiling-point sensitive organic solvents, conventional high-temperature distillation can easily lead to solvent decomposition or mother liquor denaturation, affecting the purity of the recovered product.

[0003] While existing flash evaporation units can lower the boiling point of solvents through vacuum negative pressure, the preheating of the feed mother liquor relies on external heat sources (such as steam or electric heating), resulting in significant energy waste. Simultaneously, the residual heat before the gaseous solvent condenses is not effectively utilized and is directly dissipated through the cooling system, further increasing system energy consumption. Furthermore, the residual mother liquor after flash evaporation still contains small amounts of organic solvents, which traditional processes often directly discharge or require secondary treatment, not only wasting resources but also increasing environmental risks.

[0004] Meanwhile, waste heat recovery and utilization generally uses horizontal flow heat exchangers. However, the heat exchange efficiency of existing horizontal flow heat exchangers drops significantly when the material flow rate is high. In order to improve the efficiency of waste heat utilization, further improvements are needed to the horizontal flow heat exchangers.

[0005] Existing flat-tube parallel-flow heat exchangers rely solely on the fins on the outer side of the tubes for heat exchange with the medium, resulting in low heat exchange efficiency. For example, patent application number 201621232029.3 discloses a multi-row flat-tube water-cooled parallel-flow heat exchanger. This exchanger stacks multiple layers of flat tubes into rows, with two rows of stacked flat tubes inserted into left and right end plates to form the heat exchange core. The hot water enters the distribution chamber through the inlet pipe, then flows through one row of flat tubes, converges in the return chamber, and then flows back to the confluence chamber through another row of flat tubes. Finally, it flows out through the outlet pipe. The heat dissipation fins between the flat tubes dissipate the heat from the hot water. However, this heat exchanger relies solely on the fins on the outer side of the tubes for heat exchange with the medium. When the fluid velocity inside the flat tubes is high, the heat exchange efficiency is affected. Utility Model Content

[0006] The main objective of this invention is to provide an energy-saving vacuum flash evaporation organic solvent recovery device that can improve waste heat recovery efficiency.

[0007] To achieve the above objectives, the technical solution provided by this utility model is as follows: An energy-saving vacuum flash evaporation organic solvent recovery device includes a flash tower, with a liquid outlet pipe fixedly connected to the lower end of the flash tower and a circulation pipe fixedly connected to the lower end of the flash tower. A circulation heater is installed on the circulation pipe. A gas phase pipe is fixedly connected to the upper end of the flash tower, and a vacuum pump is installed on the gas phase pipe. The gas phase pipe is connected to the shell side of a horizontal flow heat exchanger. The material discharged from the shell side of the horizontal flow heat exchanger enters a storage tank after passing through an end cooler. An atomizing spray head is fixedly installed inside the upper part of the flash tower, and a liquid inlet pipe is connected to the atomizing spray head. A booster pump and a main heater are installed on the liquid inlet pipe, and the liquid inlet pipe is connected to the tube side of the horizontal flow heat exchanger.

[0008] Specifically, the tube side of the terminal cooler is connected to the shell side of the horizontal flow heat exchanger, and the coolant flows through the shell side of the terminal cooler.

[0009] Specifically, the main heater is a steam heater.

[0010] Specifically, the coaxial heat exchanger includes a shell, with inner shells fixed to both the left and right sides. A drain pipe and an inlet pipe are fixedly and sealed to the left and right ends of the shell, respectively, communicating with the inner shells on the left and right sides. The drain pipe is connected to the liquid inlet pipe, and the inlet pipe is connected to the busbar. An inlet pipe is fixedly connected to the upper end of the shell, communicating with the gas phase pipe. An outlet pipe is fixed in the inner shell on the right side, with one end sealed and the other end extending to the outside of the shell. The outlet end on the outside of the shell is connected to the tube side of the end cooler via a pipeline. A... The connecting pipe is sealed at one end and connected to the lower end of the shell at the other end. Multiple outer flat tubes are fixed between the two inner shells. The left and right ends of the outer flat tubes are fixedly and sealed to the left and right inner shells respectively. Multiple baffles are fixed inside the outer shell between the two inner shells. The outer flat tubes pass through the multiple baffles and are fixedly connected to the baffles. Each outer flat tube is provided with an inner flat tube, which passes through the outer flat tube. There is a gap between the outer flat tube and its inner flat tube. The left end of the inner flat tube is fixedly and sealed to the connecting pipe, and the right end of the inner flat tube is fixedly and sealed to the outlet pipe.

[0011] Specifically, an upper distributor is fixed inside the upper end of the housing, and multiple outlet holes are evenly distributed at the lower end of the upper distributor. The upper end of the upper distributor is connected to the inlet pipe. A lower distributor is fixed inside the lower end of the housing, and multiple inlet holes are opened at the upper end of the lower distributor. The left end of the lower distributor is connected to the connecting pipe.

[0012] Specifically, both the inner flat tube and the outer flat tube are copper tubes.

[0013] Specifically, the baffle fins are formed by bending copper plates.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. The negative pressure environment of the flash tower reduces the risk of solvent thermal decomposition. The air pump, circulation pump and booster pump are linked to achieve pressure and temperature self-balance. The gas phase pipeline is transported under negative pressure throughout to prevent leakage. The main heater is physically isolated from the solvent to avoid the risk of combustion and explosion.

[0015] 2. The gaseous solvent first enters the shell side of the co-flow heat exchanger to preheat the mother liquor, and then flows through the inner flat tube for secondary heat exchange. This improves the waste heat utilization rate, significantly reduces the load on the main heater, and only requires a small amount of additional heat energy. The overall energy saving rate of the system exceeds the industry average.

[0016] 3. Atomized spraying increases the surface area of ​​the mother liquor, instantly vaporizing most of the solvent under negative pressure. A circulating heater continuously heats the residual mother liquor at the bottom of the column, thoroughly vaporizing the residual solvent. The terminal cooler ensures complete liquefaction and recovery of the gaseous solvent, improving recovery purity.

[0017] 4. The baffle fins force turbulent flow of the gas phase solvent, avoiding impurity deposition. The shell integrates the inner shell, distributor, and flat tube assembly, resulting in a significantly smaller volume compared to traditional shell-and-tube heat exchangers. Attached Figure Description

[0018] Figure 1 This is a structural block diagram of the device.

[0019] Figure 2 This is a cross-sectional view of a horizontal flow heat exchanger.

[0020] Figure 3 This is a schematic diagram showing the connection between the baffle fins and the outer flat tube.

[0021] The components in the attached diagram are named as follows: 1. Flash tower, 2. Circulating heater, 3. Circulating pipeline, 4. Liquid outlet pipeline, 5. Atomizing spray head, 6. Liquid inlet pipeline, 7. Booster pump, 8. Gas phase pipeline, 9. Vacuum pump, 10. Horizontal flow heat exchanger, 11. Terminal cooler, 12. Shell, 13. Inlet pipe, 14. Outlet pipe, 15. Drain pipe, 16. Inlet pipe, 17. Inner shell, 18. Upper distributor, 19. Lower distributor, 20. Connecting pipe, 21. Outer flat tube, 22. Inner flat tube, 23. Baffle fin, 24. Main heater. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0023] Example 1: Refer to Figure 1 As shown, the energy-saving vacuum flash evaporation organic solvent recovery device includes a flash tower 1, and the lower end of the flash tower 1 is fixedly connected to an outlet pipe 4.

[0024] The lower end of the flash tower 1 is fixedly connected to a circulation pipe 3, and a circulation heater 2 is installed on the circulation pipe 3.

[0025] A gas phase pipeline 8 is fixedly connected to the upper end of the flash tower 1. A vacuum pump 9 is installed on the gas phase pipeline 8. The gas phase pipeline 8 is connected to the shell side of the horizontal flow heat exchanger 10. The material discharged from the shell side of the horizontal flow heat exchanger 10 enters the storage tank after passing through the end cooler 11. Specifically, the tube side of the end cooler 11 is connected to the shell side of the horizontal flow heat exchanger 10, and the coolant flows through the shell side of the end cooler 11.

[0026] The upper part of the flash tower 1 is fixed with an atomizing spray head 5. The liquid inlet pipe 6 is connected to the atomizing spray head 5. The liquid inlet pipe 6 is equipped with a booster pump 7 and a main heater 24. The main heater 24 is a steam heater. The liquid inlet pipe 6 is connected to the tube side of the horizontal flow heat exchanger 10.

[0027] During operation, the vacuum pump 9 is started to maintain negative pressure inside the flash tower 1. The mother liquor flows through the tube side of the horizontal heat exchanger 10 and is heated by the main heater 24. The heated mother liquor is pressurized by the booster pump 7 and then atomized and sprayed into the flash tower 1 from the atomizing spray head 5. After the heated mother liquor is atomized and sprayed out from the atomizing spray head 5, the gaseous organic solvent rises and is discharged from the gas phase pipeline 8. The remaining mother liquor enters the lower end of the flash tower 1. The circulating heater 2 is started. The built-in circulating pump of the circulating heater 2 makes the remaining mother liquor in the lower end of the flash tower 1 circulate and heat, thereby causing the remaining organic solvent in the mother liquor in the lower end of the flash tower 1 to vaporize and rise.

[0028] After the vaporized organic solvent enters the shell side of the co-flow heat exchanger 10, it can heat the mother liquor flowing through the tube side of the co-flow heat exchanger 10, thereby realizing the utilization of the waste heat of the gaseous organic solvent. After the gaseous organic solvent is discharged from the shell side of the co-flow heat exchanger 10, it is cooled again by the terminal cooler 11 and condensed into liquid and enters the storage tank for collection.

[0029] Example 2: Based on Example 1, referring to... Figure 2 and Figure 3 As shown, the co-current heat exchanger 10 includes a shell 12, with inner shells 17 fixed to both the left and right sides of the shell 12. A drain pipe 15 and an inlet pipe 16 are fixedly and sealed to the left and right ends of the shell 12, respectively, and the drain pipe 15 and inlet pipe 16 are connected to the inner shells 17 on the left and right sides, respectively. The drain pipe 15 is connected to the liquid inlet pipe 6, and the inlet pipe 16 is connected to the busbar pipeline.

[0030] The upper end of the housing 12 is fixedly connected to the inlet pipe 13, and the upper distributor 18 is fixed inside the upper end of the housing 12. Multiple outlet holes are evenly distributed at the lower end of the upper distributor 18. The upper end of the upper distributor 18 is connected to the inlet pipe 13, and the inlet pipe 13 is connected to the gas phase pipeline 8.

[0031] An outlet pipe 14 is fixed in the inner shell 17 on the right side. One end of the outlet pipe 14 is sealed, and the other end of the outlet pipe 14 extends to the outside of the shell 12. The end of the outlet pipe 14 on the outside of the shell 12 is connected to the tube side of the end cooler 11 through a pipeline.

[0032] A connecting pipe 20 is fixed in the inner shell 17 on the left side. One end of the connecting pipe 20 is blocked, and the other end of the connecting pipe 20 is connected to the lower end of the shell 12.

[0033] A lower distributor 19 is fixed inside the lower end of the housing 12. The upper end of the lower distributor 19 has multiple inlet holes, and the left end of the lower distributor 19 is connected to the connecting pipe 20.

[0034] Multiple outer flat tubes 21 are fixed between the two inner shells 17. The left and right ends of the outer flat tubes 21 are fixedly and sealed to the inner shells 17 on the left and right sides respectively. Multiple baffles 23 are fixed inside the outer shell between the two inner shells 17. The outer flat tubes 21 pass through the multiple baffles 23 and are fixedly connected to the baffles 23.

[0035] Each outer flat tube 21 is provided with an inner flat tube 22, which penetrates the outer flat tube 21. There is a gap between the outer flat tube 21 and its inner flat tube 22. The left end of the inner flat tube 22 is fixedly and sealed to the connecting tube 20, and the right end of the inner flat tube 22 is fixedly and sealed to the outlet tube 14.

[0036] Both the inner flat tube 22 and the outer flat tube 21 are copper tubes. The baffle fin 23 is formed by bending a copper plate.

[0037] The gaseous organic solvent enters the upper distributor 18 through the inlet pipe 13 and is discharged into the housing 12 through multiple outlet holes of the upper distributor 18. Under the baffle action of multiple baffle fins 23, the gaseous organic solvent flows downward within the housing 12. The mother liquor in the mother liquor pipeline enters the inner shell 17 on the right side through the inlet pipe 16 and flows through the gap between the outer flat tube 21 and the inner flat tube 22. After passing through the gap between the outer flat tube 21 and the inner flat tube 22, the mother liquor enters the inner shell 17 on the left side and is discharged from the outlet pipe 15. The downward-flowing gaseous organic solvent... The organic solvent exchanges heat with the mother liquor flowing between the outer flat tube 21 and the inner flat tube 22 through the baffle fin 23 and the outer flat tube 21. After entering the lower end of the shell 12, the gaseous organic solvent enters the lower distributor 19 through the inlet hole. The gaseous organic solvent in the lower distributor 19 flows through the connecting pipe 20, the inner flat tube 22 and the outlet pipe 14 in sequence. When the gaseous organic solvent flows through the inner flat tube 22, it can exchange heat with the mother liquor again, thus improving the waste heat utilization efficiency of the gaseous organic solvent.

[0038] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An energy-saving vacuum flash evaporation organic solvent recovery device, comprising a flash tower (1), wherein the lower end of the flash tower (1) is fixedly connected to a liquid outlet pipe (4), characterized in that, A circulation pipeline (3) is fixedly connected to the lower end of the flash tower (1), and a circulation heater (2) is installed on the circulation pipeline (3). A gas phase pipeline (8) is fixedly connected to the upper end of the flash tower (1), and a vacuum pump (9) is installed on the gas phase pipeline (8). The gas phase pipeline (8) is connected to the shell side of the horizontal flow heat exchanger (10). The material discharged from the shell side of the horizontal flow heat exchanger (10) enters the storage tank after passing through the end cooler (11). An atomizing spray head (5) is fixedly installed inside the upper part of the flash tower (1). The liquid inlet pipeline (6) is connected to the atomizing spray head (5), and a booster pump (7) is installed on the liquid inlet pipeline (6). ) and main heater (24), the liquid inlet pipe (6) is connected to the tube side of the horizontal flow heat exchanger (10); the horizontal flow heat exchanger (10) includes a shell (12), and inner shells (17) are fixed on both the left and right sides of the shell (12). The left and right ends of the shell (12) are respectively fixedly and sealed with a drain pipe (15) and an inlet pipe (16). The drain pipe (15) and the inlet pipe (16) are respectively connected to the inner shells (17) on the left and right sides. The drain pipe (15) is connected to the liquid inlet pipe (6), and the inlet pipe (16) is connected to the busbar. The upper end of the shell (12) is fixedly connected with an inlet pipe (13). 3) Connected to the gas phase pipeline (8), an outlet pipe (14) is fixed in the inner shell (17) on the right side. One end of the outlet pipe (14) is sealed, and the other end of the outlet pipe (14) extends to the outside of the shell (12). The end of the outlet pipe (14) on the outside of the shell (12) is connected to the tube side of the end cooler (11) through a pipeline. A connecting pipe (20) is fixed in the inner shell (17) on the left side. One end of the connecting pipe (20) is sealed, and the other end of the connecting pipe (20) is connected to the lower end of the shell (12). Multiple outer flat tubes (21) are fixed between the two inner shells (17). The left and right ends of the outer flat tubes (21) are respectively It is fixedly and sealed to the inner shells (17) on the left and right sides. Multiple baffles (23) are fixed inside the outer shell between the two inner shells (17). The outer flat tube (21) passes through the multiple baffles (23). The outer flat tube (21) is fixedly connected to the baffles (23). An inner flat tube (22) is provided inside the outer flat tube (21). The inner flat tube (22) passes through the outer flat tube (21). A gap is provided between the outer flat tube (21) and its inner flat tube (22). The left end of the inner flat tube (22) is fixedly and sealed to the connecting pipe (20). The right end of the inner flat tube (22) is fixedly and sealed to the outlet pipe (14).

2. The energy-saving vacuum flash evaporation organic solvent recovery device according to claim 1, characterized in that, The tube side of the terminal cooler (11) is connected to the shell side of the co-current heat exchanger (10), and the coolant flows through the shell side of the terminal cooler (11).

3. The energy-saving vacuum flash evaporation organic solvent recovery device according to claim 1, characterized in that, The main heater (24) is a steam heater.

4. The energy-saving vacuum flash evaporation organic solvent recovery device according to claim 1, characterized in that, An upper distributor (18) is fixed inside the upper end of the housing (12). Multiple outlet holes are evenly distributed at the lower end of the upper distributor (18). The upper end of the upper distributor (18) is connected to the inlet pipe (13). A lower distributor (19) is fixed inside the lower end of the housing (12). Multiple inlet holes are opened at the upper end of the lower distributor (19). The left end of the lower distributor (19) is connected to the connecting pipe (20).

5. The energy-saving vacuum flash evaporation organic solvent recovery device according to claim 1, characterized in that, Both the inner flat tube (22) and the outer flat tube (21) are copper tubes.

6. The energy-saving vacuum flash evaporation organic solvent recovery device according to claim 1, characterized in that, The baffle fin (23) is formed by bending a copper plate.

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