Energy-saving vacuum flash ammonia stripping recovery device

Abstract

The utility model relates to the field of ammonia-containing process water and ammonia-containing wastewater, in particular to an energy-saving vacuum flash evaporation ammonia removal and recovery device. The device comprises a mother liquor tank, the mother liquor tank is communicated with a lifting pump, the lifting pump is communicated with the tube pass of a first heat exchanger, the tube pass of the first heat exchanger is communicated with the tube pass of a second heat exchanger, the tube pass of the second heat exchanger is communicated with the upper end of a flash evaporation tower, the lower end of the flash evaporation tower is communicated with a circulating pump, the circulating pump is communicated with the tube pass of a steam heater, the tube pass of the steam heater is communicated with the upper end of the flash evaporation tower, the shell pass of the steam heater is communicated with a high-temperature steam pipeline, the upper end of the flash evaporation tower is communicated with the shell pass of the first heat exchanger, the shell pass of the first heat exchanger is communicated with the tube pass of a condenser, and the upper end of a jacketed tank is communicated with a vacuum pump. In the utility model, the high-temperature ammonia gas discharged from the flash evaporation tower flows through the shell pass of the first heat exchanger, thereby preheating the low-temperature mother liquor entering the system, reducing the ammonia gas temperature, facilitating subsequent cooling, and reducing steam consumption for subsequent heating of the mother liquor.

Description

Technical Field

[0001] This utility model relates to the field of ammonia-containing process water and ammonia-containing wastewater, specifically to an energy-saving vacuum flash evaporation ammonia removal and recovery device. Background Technology

[0002] In the fields of industrial wastewater treatment and resource recovery, vacuum flash evaporation ammonia removal technology is widely used to efficiently recover ammonia from mother liquor (such as ammonia-containing solutions in chemical production or wastewater) and convert it into reusable ammonia water. This technology lowers the boiling point through a vacuum environment, promoting rapid evaporation of ammonia, thereby achieving energy-saving ammonia removal. However, existing vacuum flash evaporation ammonia removal devices suffer from significant energy efficiency bottlenecks during operation: First, ammonia carries a large amount of waste heat when discharged from the flash tower, but existing systems lack an effective heat recovery mechanism, resulting in the direct loss of this heat energy and increasing overall energy consumption; second, the waste heat of high-temperature steam is not fully utilized during steam heating, causing energy waste; in addition, the cooling process also has defects, such as the system's inability to maintain a stable cooling effect when the cooling medium is interrupted, affecting the ammonia condensation efficiency, leading to a decrease in ammonia recovery rate and an increase in operating costs. These problems not only increase operating energy consumption but also limit the economic and environmental benefits of the device in continuous industrial applications.

[0003] Therefore, it is necessary to develop an innovative energy-saving vacuum flash ammonia removal and recovery device. By optimizing the heat exchange structure, the waste heat of ammonia and steam can be utilized in a stepwise manner, and the reliability of the cooling system can be improved, thereby significantly reducing energy consumption and improving resource recovery efficiency. Utility Model Content

[0004] The main purpose of this invention is to provide a vacuum flash ammonia removal and recovery device that can reduce energy consumption.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows: An energy-saving vacuum flash ammonia removal and recovery unit includes a mother liquor tank connected to a booster pump, which is connected to the tube-side inlet of a first heat exchanger. The tube-side outlet of the first heat exchanger is connected to the tube-side inlet of a second heat exchanger, and the tube-side outlet of the second heat exchanger is connected to a first atomizing spray head inside the upper part of the flash tower. The lower part of the flash tower is connected to a circulating pump, which is connected to the tube-side inlet of a steam heater. The tube-side outlet of the steam heater is connected to a second atomizing spray head inside the upper part of the flash tower, and the shell-side inlet of the steam heater is connected to a high-temperature steam pipe. The steam heater's shell-side outlet is connected to the second heat exchanger's shell-side inlet, the second heat exchanger's shell-side outlet is connected to the steam reflux line, the upper end of the flash tower is connected to the first heat exchanger's shell-side inlet, the first heat exchanger's shell-side outlet is connected to the condenser's tube-side inlet, the condenser's tube-side outlet is connected to the lower end of the jacketed tank, the jacketed tank's upper end is connected to the vacuum pump, the cooling line is connected to the condenser's shell-side inlet, the condenser's shell-side outlet is connected to the jacketed tank's jacket inlet, and the jacketed tank's jacket outlet is connected to the condensate reflux line.

[0006] Specifically, the first atomizing spray head and the second atomizing spray head are staggered inside the flash tower.

[0007] Specifically, a second filter is provided between the inlet of the circulating pump and the steam heater.

[0008] Specifically, a first filter is installed between the booster pump and the tube inlet of the first heat exchanger.

[0009] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. The high-temperature ammonia gas stream exiting the flash distillation tower preheats the low-temperature mother liquor entering the system as it passes through the shell side of the first heat exchanger. This lowers the ammonia gas temperature, facilitating subsequent cooling, and also reduces steam consumption for subsequent heating of the mother liquor. The waste heat from the medium-temperature steam discharged from the steam heater enters the shell side of the second heat exchanger to reheat the preheated mother liquor, forming a stepped heating structure that combines preheating and main heating, maximizing the extraction of residual heat energy from the steam. The two-stage heat exchanger series design achieves synergistic recovery of ammonia and steam waste heat, significantly reducing the overall energy consumption of the mother liquor heating process.

[0010] 2. The cooling medium flows sequentially through the condenser shell side to cool ammonia gas, and then through the jacketed tank to cool ammonia water, forming a cooling chain and improving the utilization rate of the medium. The low-temperature ammonia water in the jacketed tank can maintain short-term cooling capacity when the cooling medium is interrupted, avoiding interruption of ammonia condensation and enhancing the system's fault tolerance and operational stability.

[0011] 3. The first and second atomizing spray heads are staggered in the flash tower to expand the atomization coverage area of ​​the mother liquor, increase the gas-liquid contact interface, and accelerate the escape of ammonia. The mother liquor is heated and flashed multiple times by the circulating pump, steam heater and second spray head to ensure the full removal of residual ammonia and improve the ammonia recovery rate.

[0012] 4. The first and second filters intercept impurities to prevent clogging of the heat exchanger and spray head, reduce maintenance frequency, ensure continuous production, and distribute the heating task through two-stage heat exchangers to avoid excessive load on a single piece of equipment and extend the service life of key components.

[0013] 5. Ammonia gas is efficiently converted into reusable ammonia water through dual cooling via condensation and jacketed tank, realizing waste resource utilization; the waste heat recovery mechanism reduces the amount of external steam and cooling medium used, directly reducing carbon emissions and operating costs, and meeting the requirements of green manufacturing. Attached Figure Description

[0014] Figure 1 This is a structural connection block diagram of the device.

[0015] The components in the attached diagram are named as follows: 1. Mother liquor tank, 2. Booster pump, 3. First filter, 4. First heat exchanger, 5. Second heat exchanger, 6. Steam heater, 7. Second filter, 8. Circulation pump, 9. Flash tower, 10. First atomizing spray head, 11. Second atomizing spray head, 12. Condenser, 13. Jacketed tank, 14. Vacuum pump. Detailed Implementation

[0016] 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.

[0017] Reference Figure 1 As shown, the energy-saving vacuum flash evaporation ammonia recovery device includes a mother liquor tank 1, which is connected to a booster pump 2. The booster pump 2 is connected to the tube-side inlet of a first heat exchanger 4, and a first filter 3 is installed between the booster pump 2 and the tube-side inlet of the first heat exchanger 4. The tube-side outlet of the first heat exchanger 4 is connected to the tube-side inlet of a second heat exchanger 5, and the tube-side outlet of the second heat exchanger 5 is connected to a first atomizing spray head 10 inside the upper end of the flash tower 9.

[0018] The lower end of the flash tower 9 is connected to the circulating pump 8, which is connected to the tube-side inlet of the steam heater 6. A second filter 7 is installed between the circulating pump 8 and the tube-side inlet of the steam heater 6. The tube-side outlet of the steam heater 6 is connected to the second atomizing spray head 11 inside the upper end of the flash tower 9. The first atomizing spray head 10 and the second atomizing spray head 11 are staggered inside the flash tower 9.

[0019] The shell-side inlet of steam heater 6 is connected to the high-temperature steam pipeline, the shell-side outlet of steam heater 6 is connected to the shell-side inlet of second heat exchanger 5, and the shell-side outlet of second heat exchanger 5 is connected to the steam return pipeline.

[0020] The upper end of the flash tower 9 is connected to the shell-side inlet of the first heat exchanger 4, the shell-side outlet of the first heat exchanger 4 is connected to the tube-side inlet of the condenser 12, the tube-side outlet of the condenser 12 is connected to the lower end of the jacketed tank 13, and the upper end of the jacketed tank 13 is connected to the vacuum pump 14.

[0021] The cooling pipeline is connected to the shell-side inlet of the condenser 12, the shell-side outlet of the condenser 12 is connected to the jacket inlet of the jacketed tank 13, and the jacket outlet of the jacketed tank 13 is connected to the condensate return pipeline.

[0022] During operation, the booster pump 2 and vacuum pump 14 are started. The booster pump 2 causes the mother liquor in the mother liquor tank 1 to pass through the first filter 3, the tube side of the first heat exchanger 4, the tube side of the second heat exchanger 5 and the first atomizing spray head 10 in sequence into the flash tower 9, where the mother liquor is stored.

[0023] like Figure 1 As shown, when a certain amount of mother liquor is stored in the lower end of the flash tower 9, the steam flows through the shell side of the steam heater 6, and the cooling medium flows through the shell side of the condenser 12 and the jacket of the jacketed tank 13. Figure 1 The hollow arrows indicate the direction of steam flow. Figure 1 The solid arrow in the image indicates the flow direction of the mother liquor at the lower end of flash tower 9. Figure 1 The dashed hollow arrow in the image indicates the flow direction of the mother liquor in mother liquor tank 1. Figure 1 The open arrow in the solid line indicates the direction of ammonia flow. Figure 1 The open arrow in the dashed line indicates the flow direction of the cooling medium.

[0024] Start the circulation pump 8. The circulation pump 8 causes the mother liquor in the lower end of the flash tower 9 to flow sequentially through the tube side of the second filter 7, the steam heater 6, and the second atomizing spray head 11 before entering the flash tower 9. During the process of the mother liquor in the lower end of the flash tower 9 flowing through the tube side of the steam heater 6, it is heated by the steam flowing through the shell side of the steam heater 6. After being heated, the mother liquor is sprayed out from the second atomizing spray head 11, and the ammonia gas in the mother liquor rises in the flash tower 9.

[0025] After being discharged from the top of the flash tower 9, ammonia gas flows sequentially through the shell side of the first heat exchanger 4 and the tube side of the condenser 12 before entering the jacketed tank 13. As the ammonia gas flows through the tube side of the condenser 12, it is cooled by the cooling medium flowing through the shell side of the condenser 12. Once inside the jacketed tank 13, the ammonia gas mixes with the water in the jacketed tank 13 to form ammonia water.

[0026] After the cooling medium flows through the jacket of the jacketed tank 13, it can cool the ammonia water inside the jacketed tank 13. When the cooling medium is interrupted, the low-temperature ammonia water can continue to cool the ammonia gas for a certain period of time, which improves the utilization efficiency and safety of the cooling medium.

[0027] The ammonia gas discharged from the top of the flash tower 9 preheats the mother liquor flowing through the tubes of the first heat exchanger 4 as it passes through the shell side of the first heat exchanger 4, while simultaneously lowering the temperature of the ammonia gas. The preheated mother liquor then flows through the tubes of the second heat exchanger 5 and is heated by the steam flowing through the shell side of the second heat exchanger 5. After being heated, the mother liquor flowing through the tubes of the second heat exchanger 5 is sprayed out from the first atomizing spray head 10 into the flash tower 9. After the heated mother liquor is sprayed out from the first atomizing spray head 10, the ammonia gas rises and is discharged from the top of the flash tower 9.

[0028] By setting up the first heat exchanger 4 and the second heat exchanger 5, the waste heat of the ammonia gas discharged from the top of the flash tower 9 and the waste heat of the steam flowing through the shell side of the steam heater 6 can be utilized. The waste heat of the ammonia gas discharged from the top of the flash tower 9 and the waste heat of the steam flowing through the shell side of the steam heater 6 can be used to heat the mother liquor in stages, which improves the efficiency of waste heat recovery and reduces energy consumption.

[0029] 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 ammonia recovery device, comprising a mother liquor tank (1) connected to a booster pump (2), characterized in that, The booster pump (2) is connected to the tube-side inlet of the first heat exchanger (4), the tube-side outlet of the first heat exchanger (4) is connected to the tube-side inlet of the second heat exchanger (5), the tube-side outlet of the second heat exchanger (5) is connected to the first atomizing spray head (10) inside the upper end of the flash tower (9), the lower end of the flash tower (9) is connected to the circulating pump (8), the circulating pump (8) is connected to the tube-side inlet of the steam heater (6), the tube-side outlet of the steam heater (6) is connected to the second atomizing spray head (11) inside the upper end of the flash tower (9), the shell-side inlet of the steam heater (6) is connected to the high-temperature steam pipeline, and the shell-side outlet of the steam heater (6) is connected to the high-temperature steam pipeline. The shell-side inlet of the second heat exchanger (5) is connected, the shell-side outlet of the second heat exchanger (5) is connected to the steam reflux line, the upper end of the flash tower (9) is connected to the shell-side inlet of the first heat exchanger (4), the shell-side outlet of the first heat exchanger (4) is connected to the tube-side inlet of the condenser (12), the tube-side outlet of the condenser (12) is connected to the lower end of the jacketed tank (13), the upper end of the jacketed tank (13) is connected to the vacuum pump (14), the cooling line is connected to the shell-side inlet of the condenser (12), the shell-side outlet of the condenser (12) is connected to the jacket inlet of the jacketed tank (13), and the jacket outlet of the jacketed tank (13) is connected to the condensate reflux line.

2. The energy-saving vacuum flash ammonia removal and recovery device according to claim 1, characterized in that, The first atomizing spray head (10) and the second atomizing spray head (11) are staggered inside the flash tower (9).

3. The energy-saving vacuum flash ammonia removal and recovery device according to claim 1, characterized in that, A second filter (7) is provided between the inlet of the circulating pump (8) and the steam heater (6).

4. The energy-saving vacuum flash ammonia removal and recovery device according to claim 1, characterized in that, A first filter (3) is provided between the booster pump (2) and the tube inlet of the first heat exchanger (4).

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