A coking ammonia water heat pump ammonia stripping system

Abstract

This utility model relates to the field of coking ammonia water treatment technology, and in particular to a coking ammonia water heat pump ammonia stripping system, which includes an ammonia stripping tower, a heat exchanger, a first pipe, a third pipe, a shrinkage unit, an evaporator, a steam compressor, a reboiler, a sixth pipe, and a seventh pipe. The ammonia stripping wastewater generated by the ammonia stripping tower is flash-evaporated into secondary steam in the evaporator, and then pressurized and heated by the steam compressor before being returned to the ammonia stripping tower as stripping steam, thereby effectively reducing the consumption of external steam and effectively reducing the cost of ammonia stripping. The ammonia stripping wastewater from the evaporator is sent to the shrinkage unit to exchange heat with the ammonia vapor at the top of the tower. The ammonia stripping wastewater is filtered by an activated carbon filtration adsorption device before being sent to the evaporator, removing impurities such as oil from the wastewater and effectively improving the heat transfer efficiency. The shrinkage unit uses ammonia stripping wastewater instead of circulating water, which does not consume circulating water, saves water resources, and further reduces the cost of ammonia stripping.

Description

Technical Field

[0001] This utility model relates to the field of coking ammonia water treatment technology, and in particular to a coking ammonia water heat pump ammonia stripping system. Background Technology

[0002] For every ton of coke produced during the coking process, 0.3-0.5 tons of coking ammonia water are generated. The ammonia stripping process for coking ammonia water generally uses steam stripping to remove components such as NH3, H2S, and HCN from the ammonia water.

[0003] Currently, commonly used coking ammonia water stripping systems include a stripping tower, a heat exchanger, a first pipe, and a third pipe. The lower middle part of the stripping tower has a steam inlet and a first ammonia wastewater outlet, the upper middle part has a coking ammonia water inlet, and the top of the stripping tower has an ammonia vapor outlet. The first ammonia wastewater outlet of the stripping tower is connected to the ammonia wastewater inlet of the heat exchanger through a second pipe, and an ammonia wastewater transfer pump is installed on the second pipe. One end of the third pipe is connected to the first ammonia wastewater outlet of the heat exchanger, and the other end of the third pipe is the connection end of the ammonia wastewater treatment device. One end of the first pipe is the coking ammonia water connection end, and the other end of the first pipe is connected to the coking ammonia water inlet of the heat exchanger. The coking ammonia water outlet of the heat exchanger is connected to the coking ammonia water inlet of the stripping tower through a fourth pipe. When treating coking ammonia water with ammonia stripping, the coking ammonia water supply device is first connected to the coking ammonia water connection terminal, and the steam supply device is connected to the steam inlet. The coking ammonia water enters the upper part of the ammonia stripping tower through the first pipe, heat exchanger, and fourth pipe. The coking ammonia water descending from the upper part of the ammonia stripping tower and the steam rising from the lower part of the ammonia stripping tower undergo countercurrent mass and heat transfer to complete the ammonia stripping process within the ammonia stripping tower. The ammonia vapor generated from the ammonia stripping process enters the gas system through other equipment from the ammonia vapor outlet at the top of the ammonia stripping tower. The resulting ammonia stripping wastewater is transported to the ammonia stripping wastewater treatment device for treatment through the second pipe, heat exchanger, and third pipe by the ammonia stripping wastewater transfer pump. Since the ammonia stripping wastewater has a certain amount of residual heat due to its high temperature, this residual heat can be used to preheat the coking ammonia water being treated, thereby reducing the energy consumption for ammonia stripping.

[0004] The existing coking ammonia water stripping system requires a large amount of steam, consuming about 170 kg of steam per ton of ammonia water. The cost of ammonia stripping is high, and the generated ammonia steam contains a large amount of waste heat that is not fully utilized, resulting in low energy efficiency. Utility Model Content

[0005] The technical problem solved by this utility model is to provide a low-cost coking ammonia water heat pump ammonia stripping system. The coking ammonia water heat pump ammonia stripping system fully recovers a large amount of low-temperature waste heat from the ammonia vapor at the top of the ammonia stripping tower and converts the low-temperature waste heat into secondary steam to be returned to the ammonia stripping tower for reuse.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a coking ammonia water heat pump ammonia stripping system, including an ammonia stripping tower, a heat exchanger, a first pipe, and a third pipe. The lower middle part of the ammonia stripping tower is provided with a steam inlet and a first ammonia stripping wastewater outlet; the upper middle part of the ammonia stripping tower is provided with a coking ammonia water inlet; the top of the ammonia stripping tower is provided with an ammonia vapor outlet; the first ammonia stripping wastewater outlet of the ammonia stripping tower is connected to the ammonia stripping wastewater inlet of the heat exchanger through a second pipe, and an ammonia stripping wastewater transfer pump is installed on the second pipe; one end of the third pipe is connected to the first ammonia stripping wastewater outlet of the heat exchanger, and the third... The other end of the pipeline is the connection end of the ammonia stripping wastewater treatment device. One end of the first pipeline is the connection end of the coking ammonia water. The other end of the first pipeline is connected to the coking ammonia water inlet of the heat exchanger. The coking ammonia water outlet of the heat exchanger is connected to the coking ammonia water inlet of the ammonia stripping tower through the fourth pipeline. It also includes a separator, an evaporator, a steam compressor, a reboiler, a sixth pipeline and a seventh pipeline. The ammonia vapor outlet of the ammonia stripping tower is connected to the ammonia vapor inlet of the separator through the fifth pipeline. The ammonia vapor outlet of the separator is connected to one end of the sixth pipeline. The other end of the sixth pipeline is the connection end of the ammonia vapor treatment device.

[0007] One end of the seventh pipe is connected to the second pipe, and the other end of the seventh pipe is connected to the first ammonia stripping wastewater inlet of the evaporator. The ammonia stripping wastewater outlet of the evaporator is connected to the ammonia stripping wastewater inlet of the separator through the eighth pipe, and an axial flow pump is installed on the eighth pipe. The ammonia stripping wastewater outlet of the separator is connected to the second ammonia stripping wastewater inlet of the evaporator through the ninth pipe. The steam outlet of the evaporator is connected to the steam inlet of the steam compressor through the tenth pipe, and the steam outlet of the steam compressor is connected to the steam inlet of the ammonia stripping tower through the eleventh pipe.

[0008] The lower middle part of the ammonia stripping tower is also equipped with a second ammonia stripping wastewater outlet. The second ammonia stripping wastewater outlet of the ammonia stripping tower is connected to the ammonia stripping wastewater inlet of the reboiler through the twelfth pipe. The wastewater steam outlet of the reboiler is connected to the eleventh pipe through the thirteenth pipe. The reboiler is equipped with an external steam inlet and an external condensate outlet.

[0009] Furthermore, the first ammonia wastewater inlet and the second ammonia wastewater inlet of the evaporator are located in the upper middle part of the evaporator, the ammonia wastewater outlet of the evaporator is located at the bottom of the evaporator, and the steam outlet of the evaporator is located at the top of the evaporator.

[0010] Furthermore, it also includes a fourteenth pipe, on which an ammonia stripping tower is equipped with an ammonia stripping wastewater inlet. One end of the fourteenth pipe is connected to the eighth pipe, and the other end of the fourteenth pipe is connected to the ammonia stripping wastewater inlet of the ammonia stripping tower.

[0011] Furthermore, an activated carbon filtration and adsorption device is installed on the fourteenth pipeline.

[0012] Furthermore, it also includes a gas-liquid separator, and the ammonia stripping tower is equipped with a reflux ammonia water inlet;

[0013] The ammonia vapor treatment device of the sixth pipeline is connected to the inlet of the gas-liquid separator. The ammonia water outlet of the gas-liquid separator is connected to the reflux ammonia water inlet of the ammonia stripping tower through the fifteenth pipeline, and a reflux conveying pump is installed on the fifteenth pipeline.

[0014] The beneficial effects of this invention are as follows: the ammonia stripping wastewater generated by the ammonia stripping tower is flash-evaporated in the evaporator to generate secondary steam, which is then pressurized and heated by the steam compressor and returned to the ammonia stripping tower as ammonia stripping steam. The steam consumption for ammonia stripping is ≤70kg per ton of ammonia water, thereby effectively reducing the consumption of external steam and the cost of ammonia stripping. The ammonia stripping wastewater entering the evaporator is first sent to the separator for heat exchange with the ammonia steam at the top of the tower, and the ammonia stripping wastewater is filtered by an activated carbon filtration and adsorption device to remove impurities such as oil from the wastewater, effectively improving the heat transfer efficiency. The separator uses ammonia stripping wastewater instead of circulating water, saving water resources and eliminating the consumption of circulating water, further reducing the cost of ammonia stripping. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the present invention;

[0016] The following components are labeled as follows: Ammonia stripping tower 1, reflux transfer pump 2, heat exchanger 3, first pipeline 4, third pipeline 5, second pipeline 6, ammonia stripping wastewater transfer pump 7, fourth pipeline 8, separator 9, evaporator 10, steam compressor 11, reboiler 12, sixth pipeline 13, seventh pipeline 14, fifth pipeline 15, eighth pipeline 16, axial flow pump 17, ninth pipeline 18, eleventh pipeline 20, twelfth pipeline 21, thirteenth pipeline 22, fourteenth pipeline 23, gas-liquid separator 24, fifteenth pipeline 25, reflux transfer pump 26, activated carbon filter adsorption device 27. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] like Figure 1As shown, this utility model discloses a coking ammonia water heat pump ammonia stripping system, comprising an ammonia stripping tower 1, a heat exchanger 3, a first pipe 4, and a third pipe 5. The lower middle part of the ammonia stripping tower 1 has a steam inlet and a first ammonia stripping wastewater outlet. The upper middle part of the ammonia stripping tower 1 has a coking ammonia water inlet, and the top of the ammonia stripping tower 1 has an ammonia vapor outlet. The first ammonia stripping wastewater outlet of the ammonia stripping tower 1 is connected to the ammonia stripping wastewater inlet of the heat exchanger 3 via a second pipe 6, and an ammonia stripping wastewater transfer pump 7 is installed on the second pipe 6. One end of the third pipe 5 is connected to the first ammonia stripping wastewater outlet of the heat exchanger 3, and the other end of the third pipe 5 is a treatment port for the ammonia stripping wastewater. The ammonia treatment device connection end includes a coking ammonia water connection end at one end of the first pipe 4 and a coking ammonia water inlet at the other end of the first pipe 4. The coking ammonia water outlet of the heat exchanger 3 is connected to the coking ammonia water inlet of the ammonia stripping tower 1 through the fourth pipe 8. It also includes a separator 9, an evaporator 10, a steam compressor 11, a reboiler 12, a sixth pipe 13 and a seventh pipe 14. The ammonia vapor outlet of the ammonia stripping tower 1 is connected to the ammonia vapor inlet of the separator 9 through the fifth pipe 15. The ammonia vapor outlet of the separator 9 is connected to one end of the sixth pipe 13, and the other end of the sixth pipe 13 is the ammonia vapor treatment device connection end.

[0019] One end of the seventh pipe 14 is connected to the second pipe 6, and the other end of the seventh pipe 14 is connected to the first ammonia stripping wastewater inlet of the evaporator 10. The ammonia stripping wastewater outlet of the evaporator 10 is connected to the ammonia stripping wastewater inlet of the distributor 9 through the eighth pipe 16, and an axial flow pump 17 is installed on the eighth pipe 16. The ammonia stripping wastewater outlet of the distributor 9 is connected to the second ammonia stripping wastewater inlet of the evaporator 10 through the ninth pipe 18. The steam outlet of the evaporator 10 is connected to the steam inlet of the steam compressor 11 through the tenth pipe 19, and the steam outlet of the steam compressor 11 is connected to the steam inlet of the ammonia stripping tower 1 through the eleventh pipe 20.

[0020] The lower middle part of the ammonia stripping tower 1 is also provided with a second ammonia stripping wastewater outlet. The second ammonia stripping wastewater outlet of the ammonia stripping tower 1 is connected to the ammonia stripping wastewater inlet of the reboiler 12 through the twelfth pipe 21. The wastewater steam outlet of the reboiler 12 is connected to the eleventh pipe 20 through the thirteenth pipe 22. The reboiler 12 is provided with an external steam inlet and an external condensate outlet.

[0021] For ease of adjustment and control, each pipe mentioned in this article can be equipped with a switch valve, which can be used to control whether the pipe is connected and the flow rate in the pipe.

[0022] The coking ammonia water supply device is connected to the coking ammonia water connection end, the steam supply device is connected to the external steam inlet of reboiler 12, the external condensate outlet of reboiler 12 is connected to the condensate pipe, and the connection end of the ammonia stripping wastewater treatment device of the third pipe 5 is connected to the ammonia stripping wastewater treatment device. The working principle of this utility model for the coking ammonia water ammonia stripping system is as follows: the coking ammonia water enters the upper part of the ammonia stripping tower 1 through the first pipe 4, heat exchanger 3, and fourth pipe 8. Since there is no steam in the ammonia stripping tower 1 at this time, the coking ammonia water will not undergo ammonia stripping. The coking ammonia water falls from top to bottom to the lower part of the ammonia stripping tower 1. The coking ammonia water then enters the reboiler 12 through the second ammonia stripping wastewater outlet and the twelfth pipe 21 of the ammonia stripping tower 1. At the same time, external steam is also introduced into the reboiler 12 to turn the liquid in the coking ammonia water into steam. The steam passes through the thirteenth pipe 22 and the tenth pipe 23. A steam inlet (pipeline 20) enters the ammonia stripping tower 1. The rising steam counter-currents with the descending coking ammonia water at the top of the tower, completing the ammonia stripping process. The resulting ammonia stripping wastewater is pumped by a pump. Part of the wastewater is transported via a second pipeline (pipeline 6), a heat exchanger (pipeline 3), and a third pipeline (pipeline 5) to an ammonia stripping wastewater treatment unit for further treatment. The heat exchanger (pipeline 3) preheats the coking ammonia water, reducing energy consumption during ammonia stripping. The remaining wastewater is transported via a second pipeline (pipeline 6), a seventh pipeline (pipeline 5), and a seventh pipeline (pipeline 5). The ammonia wastewater enters the evaporator 10 through pipe 14. Under the action of the axial flow pump 17, it then enters the heat exchanger 9 through the ammonia stripping wastewater outlet and the eighth pipe 16 of the evaporator 10. After heat exchange, it enters the evaporator 10 through the ninth pipe 18 for evaporation. The secondary steam generated by flash evaporation in the evaporator 10 enters the steam compressor 11 through its steam outlet and the tenth pipe 19 for compression, heating, and pressurization. The heated and pressurized secondary steam enters the ammonia stripping tower 1 through the eleventh pipe 20 and the steam inlet for ammonia stripping. The ammonia stripping wastewater after flash evaporation in the evaporator 10 exits from the evaporator 10. The ammonia stripping wastewater is discharged through the axial flow pump 17 for recycling; the ammonia vapor generated by ammonia stripping enters the separator 9 through the ammonia vapor outlet at the top of the ammonia stripping tower and the fifth pipe 15. The ammonia vapor exchanges heat with the ammonia stripping wastewater entering the separator 9, and the cooled ammonia vapor enters the ammonia vapor treatment device through the sixth pipe 13 for treatment; the secondary steam generated by the ammonia stripping wastewater in the evaporator 10 is compressed and heated by the steam compressor 11 and used as the steam source for ammonia stripping, thereby effectively reducing the consumption of external steam and effectively reducing the cost of ammonia stripping.

[0023] Specifically, the main function of heat exchanger 3 is to preheat the coking ammonia water to be treated later by using the ammonia-removed wastewater generated from ammonia stripping. The main function of the separator 9 is to exchange heat with the ammonia-removed wastewater after flash evaporation in evaporator 10 by using the ammonia vapor generated from ammonia stripping. The main function of evaporator 10 is to flash evaporate the ammonia-removed wastewater to generate secondary steam.

[0024] The preferred solution is: For example Figure 1As shown, the first ammonia wastewater inlet and the second ammonia wastewater inlet of the evaporator 10 are located in the upper middle part of the evaporator 10, the ammonia wastewater outlet of the evaporator 10 is located at the bottom of the evaporator 10, and the steam outlet of the evaporator 10 is located at the top of the evaporator 10.

[0025] This invention also includes a fourteenth pipe 23. An ammonia stripping tower 1 has an ammonia stripping wastewater inlet. One end of the fourteenth pipe 23 is connected to the eighth pipe 16, and the other end is connected to the ammonia stripping wastewater inlet of the ammonia stripping tower 1. The ammonia stripping wastewater in the eighth pipe 16 enters the ammonia stripping tower 1 through the fourteenth pipe 23. This arrangement connects the ammonia stripping tower 1, the separator 9, and the evaporator 10, allowing for adjustment of the ammonia stripping wastewater flow rate in each component based on real-time ammonia stripping conditions. To remove oil and other impurities from the ammonia stripping wastewater and improve heat transfer efficiency, an activated carbon filter adsorption device 27 is installed on the fourteenth pipe 23.

[0026] This invention also includes a gas-liquid separator 24, and a reflux ammonia water inlet is provided on the ammonia stripping tower 1. The ammonia vapor treatment device connection end of the sixth pipe 13 is connected to the inlet of the gas-liquid separator 24, and the ammonia water outlet of the gas-liquid separator 24 is connected to the reflux ammonia water inlet of the ammonia stripping tower 1 through the fifteenth pipe 25. A reflux conveying pump 2 is provided on the fifteenth pipe 25, and an ammonia vapor outlet is provided at the top of the gas-liquid separator 24. The ammonia water is refluxed back into the ammonia stripping tower 1.

[0027] In summary, this invention utilizes the ammonia stripping wastewater generated in the ammonia stripping tower 1 to flash evaporate in the evaporator 10, generating secondary steam which is then pressurized and heated by the steam compressor 11 before being returned to the ammonia stripping tower 1 as stripping steam. The steam consumption for each ton of ammonia water stripping is ≤70kg, effectively reducing external steam consumption and lowering the cost of ammonia stripping. The ammonia stripping wastewater from the evaporator 10 is pumped by an axial flow pump to the separator 9 for heat exchange with the ammonia vapor at the top of the tower. The ammonia stripping wastewater is filtered by the activated carbon filtration and adsorption device 27, removing impurities such as oil and effectively improving heat transfer efficiency. The separator 9 uses the ammonia stripping wastewater instead of circulating water, eliminating the consumption of circulating water and saving water resources, further reducing the cost of ammonia stripping.

Claims

1. A coking ammonia water heat pump ammonia stripping system, comprising an ammonia stripping tower (1), a heat exchanger (3), a first pipe (4), and a third pipe (5), wherein the lower middle part of the ammonia stripping tower (1) is provided with a steam inlet and a first ammonia stripping wastewater outlet, the upper middle part of the ammonia stripping tower (1) is provided with a coking ammonia water inlet, the top of the ammonia stripping tower (1) is provided with an ammonia vapor outlet, the first ammonia stripping wastewater outlet of the ammonia stripping tower (1) is connected to the ammonia stripping wastewater inlet of the heat exchanger (3) through a second pipe (6), and the second pipe (6) is connected to the heat exchanger (3) through a second pipe (6). A pump (7) for transferring ammonia stripping wastewater is provided. One end of the third pipe (5) is connected to the first ammonia stripping wastewater outlet of the heat exchanger (3), and the other end of the third pipe (5) is the connection end of the ammonia stripping wastewater treatment device. One end of the first pipe (4) is the connection end of the coking ammonia water, and the other end of the first pipe (4) is connected to the coking ammonia water inlet of the heat exchanger (3). The coking ammonia water outlet of the heat exchanger (3) is connected to the coking ammonia water inlet of the ammonia stripping tower (1) through the fourth pipe (8). The feature is that: It also includes a shrinkage unit (9), an evaporator (10), a steam compressor (11), a reboiler (12), a sixth pipe (13) and a seventh pipe (14). The ammonia outlet of the ammonia stripping tower (1) is connected to the ammonia inlet of the shrinkage unit (9) through the fifth pipe (15). The ammonia outlet of the shrinkage unit (9) is connected to one end of the sixth pipe (13). The other end of the sixth pipe (13) is the connection end of the ammonia treatment device. One end of the seventh pipe (14) is connected to the second pipe (6), and the other end of the seventh pipe (14) is connected to the first ammonia wastewater inlet of the evaporator (10). The ammonia wastewater outlet of the evaporator (10) is connected to the ammonia wastewater inlet of the separator (9) through the eighth pipe (16), and an axial flow pump (17) is installed on the eighth pipe (16). The ammonia wastewater outlet of the separator (9) is connected to the second ammonia wastewater inlet of the evaporator (10) through the ninth pipe (18). The steam outlet of the evaporator (10) is connected to the steam inlet of the steam compressor (11) through the tenth pipe (19), and the steam outlet of the steam compressor (11) is connected to the steam inlet of the ammonia stripping tower (1) through the eleventh pipe (20). The lower middle part of the ammonia stripping tower (1) is also provided with a second ammonia stripping wastewater outlet. The second ammonia stripping wastewater outlet of the ammonia stripping tower (1) is connected to the ammonia stripping wastewater inlet of the reboiler (12) through the twelfth pipe (21). The wastewater steam outlet of the reboiler (12) is connected to the eleventh pipe (20) through the thirteenth pipe (22). The reboiler (12) is provided with an external steam inlet and an external condensate outlet.

2. The coking ammonia water heat pump ammonia stripping system as described in claim 1, characterized in that: The first ammonia wastewater inlet and the second ammonia wastewater inlet of the evaporator (10) are located in the upper middle part of the evaporator (10), the ammonia wastewater outlet of the evaporator (10) is located at the bottom of the evaporator (10), and the steam outlet of the evaporator (10) is located at the top of the evaporator (10).

3. The coking ammonia water heat pump ammonia stripping system as described in claim 1, characterized in that: It also includes the fourteenth pipe (23), and the ammonia stripping tower (1) is equipped with an ammonia stripping wastewater inlet. One end of the fourteenth pipe (23) is connected to the eighth pipe (16), and the other end of the fourteenth pipe (23) is connected to the ammonia stripping wastewater inlet of the ammonia stripping tower (1).

4. The coking ammonia water heat pump ammonia stripping system as described in claim 3, characterized in that: An activated carbon filtration and adsorption device (27) is installed on the fourteenth pipe (23).

5. A coking ammonia water heat pump ammonia stripping system as described in any one of claims 1 to 4, characterized in that: It also includes a gas-liquid separator (24), and a reflux ammonia water inlet is provided on the ammonia stripping tower (1); The ammonia vapor treatment device connection end of the sixth pipeline (13) is connected to the inlet of the gas-liquid separator (24). The ammonia water outlet of the gas-liquid separator (24) is connected to the reflux ammonia water inlet of the ammonia stripping tower (1) through the fifteenth pipeline (25), and a reflux conveying pump (2) is installed on the fifteenth pipeline (25).

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