Ammonia distillation system

Abstract

The present application belongs to the technical field of coal gas purification, and discloses an ammonia evaporation system, which comprises an ammonia evaporation tower, an asphalt filter unit, an ammonia evaporation venting tank and a reflux unit. The first asphalt filter comprises an asphalt tank, a flow guide pipe and a partition plate. The flow guide pipe is connected with the ammonia evaporation tower and comprises an extension section. The extension section is arranged in the asphalt tank. The partition plate is arranged in the asphalt tank and divides the asphalt tank into a first space and a second space. The extension section is located in the first space. Along the extension direction of the extension section, one end of the outlet end of the partition plate away from the extension section is provided with an overflow notch. The overflow notch is connected with the first space and the second space. The asphalt tank surrounding the second space is provided with a first outlet. The first outlet is not lower than the overflow notch. The ammonia evaporation venting tank is connected with the first outlet. The reflux unit comprises a slag scraping tank, a tar ammonia water separator, an ammonia water collector and a third filter which are connected in sequence. The slag scraping tank is connected with the ammonia evaporation venting tank. The third filter is connected with the ammonia evaporation tower.

Description

Technical Field

[0001] This invention relates to the field of coal gas purification technology, and in particular to an ammonia stripping system. Background Technology

[0002] In the coking industry, residual ammonia water mainly refers to the ammonia water remaining in the condenser blower section, which is mainly a solution of ammonia and excess water (more than needed for recycling) generated during the coking process.

[0003] In the existing process, the residual ammonia water separated after the slag scraper is returned to the ammonia stripping tower through a filter. Taking a ceramic membrane filter as an example, the ceramic membrane is easily damaged, causing the filter to be unable to effectively filter the oil in the residual ammonia water. The oil enters the ammonia stripping tower and is heated by steam. After the waste liquid is discharged at the bottom of the ammonia stripping tower, the oil condenses and forms asphalt, which blocks the waste liquid channel at the bottom of the ammonia stripping tower. Summary of the Invention

[0004] The purpose of this invention is to provide an ammonia stripping system that prevents asphalt in the waste liquid from entering the ammonia stripping vent tank and other equipment and waste liquid pipelines after the filter between the slag scraper and the ammonia stripping tower is damaged, thus avoiding damage to the equipment and pipelines.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] The ammonia stripping system includes:

[0007] Ammonia stripping towers can discharge waste liquid;

[0008] An asphalt filtration unit includes a first asphalt filter, which comprises an asphalt tank, a guide pipe, and a baffle. The guide pipe is connected to the ammonia stripping tower and includes an extension section disposed within the asphalt tank. The extension section extends from its inlet end to its outlet end, and from one side of the asphalt tank downwards to the other side. The baffle is disposed within the asphalt tank and divides the asphalt tank into a first space and a second space. The extension section is located in the first space. Along the extension direction of the extension section, an overflow notch is provided at one end of the baffle away from the outlet end of the extension section. The overflow notch connects the first space and the second space. A first outlet is provided on the asphalt tank surrounding the second space, and the first outlet is not lower than the overflow notch.

[0009] Ammonia venting tank is connected to the first outlet;

[0010] The reflux unit includes a slag scraper, a tar-ammonia separator, an ammonia collector, and a third filter connected in sequence. The slag scraper is connected to the ammonia stripping vent tank, and the third filter is connected to the ammonia stripping tower. The third filter is used to filter out oil from the waste liquid.

[0011] Optionally, it also includes an ammonium sulfate unit, which includes an acid tar tank connected between the first outlet and the slag scraper tank.

[0012] Optionally, the asphalt filtration unit further includes a second asphalt filter, which is connected to the first outlet. The second asphalt filter is provided with a second outlet and a third outlet. The ammonia stripping vent is connected to the second outlet, and the acid tar tank is connected to the third outlet.

[0013] Optionally, the second asphalt filter includes an asphalt tank and an asphalt pool. The asphalt tank is connected to the first outlet, and the asphalt tank is provided with a second outlet and a third outlet. The lower end of the asphalt tank is provided with a sediment discharge port, and the asphalt pool is connected to the sediment discharge port.

[0014] Optionally, it also includes a second delivery pump connected between the asphalt tank and the acid tar tank.

[0015] Optionally, the baffle includes a connected main body and a protrusion, one end of the main body away from the protrusion is fixed to one side of the asphalt tank, the other end of the protrusion away from the main body is fixed to the other side of the asphalt tank, the top of the protrusion is lower than the main body, and the asphalt tank, the main body and the protrusion form the overflow gap.

[0016] Optionally, the first asphalt filter further includes a cover, which is sealed and removably mounted on the asphalt tank.

[0017] Optionally, the guide pipe further includes a connecting section, one end of which is connected to the inlet end of the extension section, and the other end extends out of the asphalt tank and is connected to the ammonia stripping tower.

[0018] Optionally, the ammonium sulfate unit further includes a desulfurizer connected to the acid tar tank, and the ammonia stripping system further includes a phenol-cyanide wastewater station connected to the desulfurizer.

[0019] Optionally, it also includes a third transfer pump connected between the desulfurizer and the phenol-cyanide wastewater station.

[0020] Beneficial effects:

[0021] The ammonia stripping system provided by this invention allows waste liquid flowing from the ammonia stripping tower to the first space via the outlet of a guide pipe. The waste liquid collects in the first space until it exceeds the overflow gap. Because the asphalt in the waste liquid settles downwards and is located at a lower position in the first space, it cannot cross the overflow gap and is thus trapped within the first space. Other liquids cross the overflow gap and enter the second space. Since the height of the first outlet is not lower than the overflow gap, the waste liquid accumulates in the second space until it exceeds the first outlet. Similar to the sedimentation principle in the first space, the asphalt-like substances in the waste liquid also settle in the second space, while other liquids with lower density and better flowability flow out from the first outlet and into subsequent pipelines. Regardless of whether the third filter is damaged, the sedimentation filtration of asphalt-like substances through the first and second spaces of the asphalt filtration unit prevents asphalt in the waste liquid from entering equipment such as the ammonia stripping vent tank and downstream pipelines of the asphalt filtration unit, thus avoiding damage to the equipment and pipelines. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the ammonia stripping system provided in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the first asphalt filter provided in an embodiment of the present invention;

[0024] Figure 3 This is a front view of the first asphalt filter provided in an embodiment of the present invention;

[0025] Figure 4 This is a left view of the first asphalt filter provided in an embodiment of the present invention;

[0026] Figure 5 This is a top view of the first asphalt filter provided in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the second asphalt filter provided in an embodiment of the present invention.

[0028] In the picture:

[0029] 1. Ammonia stripping tower; 101. Steam inlet; 102. Wastewater pump;

[0030] 2. First asphalt filter; 21. Asphalt tank; 211. First space; 212. Second space; 213. First outlet; 22. Guide pipe; 221. Connecting section; 222. Extension section; 23. Baffle; 231. Main body; 232. Protrusion; 24. Overflow notch; 25. Tank cover;

[0031] 3. Second asphalt filter; 31. Asphalt tank; 311. Second outlet; 312. Third outlet; 313. Sediment discharge port; 314. First inlet; 32. Asphalt pool; 33. Support frame;

[0032] 4. Ammonia venting tank;

[0033] 51. Slag scraper; 52. Tar-ammonia separator; 53. Ammonia collector; 54. Third filter;

[0034] 61. Acid tar tank; 62. Desulfurizer;

[0035] 7. Phenol and cyanide wastewater treatment plant;

[0036] 8. First delivery pump;

[0037] 9. Second delivery pump;

[0038] 10. Third transfer pump;

[0039] 11. Fourth transfer pump;

[0040] 12. Fifth delivery pump;

[0041] 13. Shrinkage unit;

[0042] 14. Saturator. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0044] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0047] like Figure 1 As shown, this embodiment provides an ammonia stripping system, which includes an ammonia stripping tower 1, an asphalt filtration unit, an ammonia stripping venting tank 4, and a reflux unit.

[0048] Ammonia stripping tower 1 is used to raise the temperature of ammonia water, reduce the solubility of ammonia in water, and achieve ammonia distillation. High-temperature steam enters ammonia stripping tower 1 through steam inlet 101 and comes into contact with the ammonia water entering the tower. The temperature of the ammonia water gradually increases, causing the ammonia in the water to evaporate continuously. The gaseous ammonia is concentrated in the fractionator 13 at the top of ammonia stripping tower 1 and then condensed into liquid in the saturator 14, which is then sent to the desulfurization process. Waste liquid is discharged from the bottom of ammonia stripping tower 1 during the ammonia stripping process.

[0049] like Figures 2-5 As shown, the asphalt filtration unit includes a first asphalt filter 2, which includes an asphalt tank 21, a guide pipe 22, and a baffle 23. The guide pipe 22 is connected to the ammonia stripping tower 1 and includes an extension section 222. The extension section 222 is disposed inside the asphalt tank 21, extending from its inlet end to its outlet end. The extension section 222 extends from one side of the asphalt tank 21 downwards to the other side. The baffle 23 is disposed inside the asphalt tank 21 and divides the asphalt tank 21 into a first space 211 and a second space 212. The extension section 222 is located in the first space 211. Along the extension direction of the extension section 222, an overflow notch 24 is provided at one end of the partition 23 away from the outlet end of the extension section 222. The overflow notch 24 connects the first space 211 and the second space 212. The asphalt tank 21 surrounding the second space 212 is provided with a first outlet 213. The first outlet 213 is located on the side of the asphalt tank 21 away from the overflow notch 24, and the first outlet 213 is not lower than the overflow notch 24. The ammonia venting tank 4 is connected to the first outlet 213 and is used to receive the waste liquid flowing out from the first outlet 213. In this embodiment, the first outlet 213 is located at the upper end of the asphalt tank 21, which is higher than the lower end of the overflow notch 24.

[0050] The extension section 222 slopes downwards, transporting the waste liquid to the bottom of the first space 211, making the waste liquid flow as close to steady as possible, which is conducive to the settling of asphalt in the waste liquid. The outlet end of the extension section 222 is far from the overflow outlet, increasing the flow path of the waste liquid, which also facilitates the settling of asphalt in the first space 211. The first outlet 213 and the overflow gap 24 are located on opposite sides of the asphalt tank 21, that is, the first outlet 213 and the outlet end of the extension section 222 are located on the same side of the asphalt tank 21, thereby increasing the flow path of the waste liquid in the second space 212, which is convenient for settling. The relative positional relationship of the extension section 222, the overflow gap 24 and the first outlet 213 results in a long flow path of waste liquid in the asphalt tank 21, and the waste liquid accumulates from low to high in both the first space 211 and the second space 212 until it overflows from the outlet at the higher level, thereby achieving effective settling of asphalt.

[0051] like Figures 2-5 As shown, optionally, the baffle 23 includes a connected main body 231 and a protrusion 232. The end of the main body 231 away from the protrusion 232 is fixed to one side of the asphalt tank 21, and the end of the protrusion 232 away from the main body 231 is fixed to the other side of the asphalt tank 21. The top of the protrusion 232 is lower than the main body 231. The asphalt tank 21, the main body 231, and the protrusion 232 form an overflow notch 24. Specifically, the inlet ends of the protrusion 232 and the extension section 222 are located on the same side of the asphalt tank 21, and the outlet ends of the main body 231 and the extension section 222 are located on the same side of the asphalt tank 21, so that the overflow notch 24 and the outlet end of the extension section 222 are located on opposite sides of the asphalt tank 21, increasing the waste liquid's travel distance and facilitating asphalt settling. In this embodiment, the main body 231 and the protrusion 232 are integrally formed sheet metal parts.

[0052] like Figures 2-5 As shown, optionally, the first asphalt filter 2 also includes a cover 25, which is a sealed and removable cover on the asphalt tank 21. In this embodiment, the open end of the asphalt tank 21 is provided with a water seal groove, and the cover 25 is placed on the water seal groove to achieve a seal on the asphalt tank 21, preventing the evaporation of waste liquid from overflowing and affecting the working environment.

[0053] like Figures 2-5 As shown, to facilitate connection to the ammonia stripping tower 1, the guide pipe 22 may optionally include a connecting section 221. One end of the connecting section 221 is connected to the inlet end of the extension section 222, and the other end extends out of the asphalt box 21 and is connected to the ammonia stripping tower 1.

[0054] like Figure 1As shown, the reflux unit includes a scraper trough 51, a tar-ammonia water separator 52, an ammonia water collector 53, and a third filter 54 connected in sequence. The scraper trough 51 is connected to the ammonia stripping vent tank 4, and the third filter 54 is connected to the ammonia stripping tower 1. The third filter 54 is used to filter out oil from the waste liquid. The scraper trough 51 is used to collect impurities in the waste liquid, the tar-ammonia water separator 52 is used to separate tar and ammonia water, and the ammonia water collector 53 is used to collect the ammonia water separated by the tar-ammonia water separator 52. In this embodiment, the tar-ammonia water separator 52 is a tar-ammonia water separation tank, the ammonia water collector 53 is a residual ammonia water tank, and the third filter 54 is a ceramic membrane filter. To transport the residual ammonia water in the ammonia water collector 53 to the third filter 54, a fifth transfer pump 12 is also provided on the pipeline between the ammonia water collector 53 and the third filter 54. In order to transport the waste liquid in the ammonia venting tank 4 to the slag scraping tank 51, a first transfer pump 8 is provided on the pipeline between the two. In this embodiment, the first transfer pump 8 is a self-priming pump.

[0055] The waste liquid flowing out of the ammonia stripping tower 1 flows to the first space 211 through the outlet end of the guide pipe 22. The waste liquid collects in the first space 211 until it is higher than the overflow gap 24. As the asphalt material in the waste liquid settles downwards and is located at a lower position in the first space 211, it cannot cross the overflow gap 24 and is trapped in the first space 211. Other liquids cross the overflow gap 24 and enter the second space 212. The height of the first outlet 213 is not lower than the overflow gap 24. The waste liquid accumulates in the second space 212 until it is higher than the first outlet 213. Similar to the sedimentation principle of the first space 211, the asphalt-like material in the waste liquid also settles in the second space 212. Other liquids with low density and good flowability flow out from the first outlet 213 and enter the subsequent pipeline. Regardless of whether the third filter 54 is damaged, the sedimentation filtration of asphalt-like substances through the first space 211 and the second space 212 of the asphalt filtration unit prevents asphalt in the waste liquid from entering equipment such as the ammonia venting tank 4 and the pipelines downstream of the asphalt filtration unit, thus avoiding damage to the equipment and pipelines.

[0056] like Figure 1 As shown, optionally, the ammonia stripping system also includes an ammonium sulfate unit, which includes an acid tar tank 61 connected between the first outlet 213 and the scraper tank 51. After filtration by the asphalt filtration unit, the waste liquid can flow to the acid tar tank 61, diluting and softening the viscous liquid in the acid tar tank 61, making the downstream pipelines and equipment of the acid tar tank 61 less prone to blockage. In this embodiment, a first switching valve is provided on the pipeline between the acid tar tank 61 and the first outlet 213 to facilitate opening or closing the pipeline from the asphalt filtration unit to the acid tar tank 61. In this embodiment, a fourth delivery pump 11 is provided on the pipeline between the acid tar tank 61 and the scraper tank 51 to transport the tar in the acid tar tank 61 to the scraper tank 51.

[0057] like Figure 1 and Figure 6 As shown, optionally, the asphalt filtration unit further includes a second asphalt filter 3, which is connected to the first outlet 213. The second asphalt filter 3 is provided with a second outlet 311 and a third outlet 312. The ammonia stripping vent tank 4 is connected to the second outlet 311, and the acid tar tank 61 is connected to the third outlet 312. The second asphalt filter 3 can further filter asphalt, further reduce the proportion of asphalt in the waste liquid, and improve the fluidity of the waste liquid.

[0058] like Figure 1 and Figure 6 As shown, optionally, the second asphalt filter 3 includes an asphalt tank 31 and an asphalt pool 32. The asphalt tank 31 is connected to the first outlet 213, and the asphalt tank 31 is provided with a second outlet 311 and a third outlet 312. The lower end of the asphalt tank 31 is provided with a sediment discharge port 313, and the asphalt pool 32 is connected to the sediment discharge port 313. The asphalt deposited in the asphalt tank 31 is collected through the asphalt pool 32, allowing the asphalt tank 31 to operate stably for a long period, avoiding frequent shutdowns for cleaning and thus reducing efficiency. In this embodiment, the asphalt tank 31 is a tank-shaped vessel, mounted on a support frame 33, with the asphalt pool 32 located below the support frame 33. In this embodiment, the asphalt tank 31 is provided with a first inlet 314, which is connected to the first outlet 213 to receive the liquid from the asphalt tank 21.

[0059] like Figure 1 As shown, optionally, the ammonia stripping system also includes a second transfer pump 9, which is connected between the asphalt tank 31 and the acid tar tank 61. The second transfer pump 9 is used to transfer the waste liquid flowing out of the third outlet 312 of the asphalt tank 31 to the acid tar tank 61.

[0060] like Figure 1 As shown, optionally, the ammonium sulfate unit also includes a desulfurizer 62, which is connected to the acid tar tank 61. The ammonia stripping system also includes a phenol-cyanide wastewater station 7, which is connected to the desulfurizer 62. The desulfurizer 62 is used to desulfurize the waste liquid transported from the acid tar tank 61, and the phenol-cyanide wastewater station 7 is used to purify the waste liquid transported from the desulfurizer 62, turning the waste liquid into greywater for recycling in other processes. In this embodiment, the desulfurizer 62 is a desulfurization venting tank.

[0061] like Figure 1 As shown, a wastewater pump 102 is installed on the pipeline between the ammonia stripping tower 1 and the phenol-cyanide wastewater station 7. The wastewater pump 102 transports part of the wastewater from the ammonia stripping tower 1 to the phenol-cyanide wastewater station 7.

[0062] like Figure 1As shown, to transport the waste liquid in the desulfurizer 62 to the phenol-cyanide wastewater station 7, the ammonia stripping system optionally includes a third transfer pump 10, which is connected between the desulfurizer 62 and the phenol-cyanide wastewater station 7. In this embodiment, the third transfer pump 10 is a self-priming pump.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An ammonia stripping system, characterized in that, include: The ammonia stripping tower (1) is capable of discharging waste liquid; An asphalt filtration unit includes a first asphalt filter (2), which includes an asphalt tank (21), a guide pipe (22), and a baffle plate (23). The guide pipe (22) is connected to the ammonia stripping tower (1). The guide pipe (22) includes an extension section (222), which is disposed inside the asphalt tank (21) and extends from the inlet end to the outlet end of the extension section (222). The extension section (222) extends from one side of the asphalt tank (21) downwards to the other side of the asphalt tank (21). The baffle plate (23) is disposed inside the asphalt tank (21) and divides the asphalt tank (21) into a first... Space (211) and second space (212), the extension section (222) is located in the first space (211), along the extension direction of the extension section (222), the partition (23) is provided with an overflow gap (24) at one end away from the outlet end of the extension section (222), the overflow gap (24) connects the first space (211) and the second space (212), the asphalt tank (21) surrounding the second space (212) is provided with a first outlet (213), the first outlet (213) is located on the side of the asphalt tank (21) away from the overflow gap (24), and the first outlet (213) is not lower than the overflow gap (24); The ammonia venting tank (4) is connected to the first outlet (213); The reflux unit includes a slag scraper (51), a tar-ammonia water separator (52), an ammonia water collector (53), and a third filter (54) connected in sequence. The slag scraper (51) is connected to the ammonia stripping vent tank (4), and the third filter (54) is connected to the ammonia stripping tower (1). The third filter (54) is used to filter out oil from the waste liquid.

2. The ammonia stripping system according to claim 1, characterized in that, It also includes an ammonium sulfate unit, which includes an acid tar tank (61) connected between the first outlet (213) and the slag scraper tank (51).

3. The ammonia stripping system according to claim 2, characterized in that, The asphalt filtration unit further includes a second asphalt filter (3), which is connected to the first outlet (213). The second asphalt filter (3) is provided with a second outlet (311) and a third outlet (312). The ammonia venting tank (4) is connected to the second outlet (311), and the acid tar tank (61) is connected to the third outlet (312).

4. The ammonia stripping system according to claim 3, characterized in that, The second asphalt filter (3) includes an asphalt tank (31) and an asphalt pool (32). The asphalt tank (31) is connected to the first outlet (213). The asphalt tank (31) is provided with a second outlet (311) and a third outlet (312). The lower end of the asphalt tank (31) is provided with a sediment discharge port (313). The asphalt pool (32) is connected to the sediment discharge port (313).

5. The ammonia stripping system according to claim 4, characterized in that, It also includes a second delivery pump (9), which is connected between the asphalt tank (31) and the acid tar tank (61).

6. The ammonia stripping system according to claim 1, characterized in that, The partition (23) includes a connected main body (231) and a protrusion (232). One end of the main body (231) away from the protrusion (232) is fixed to one side of the asphalt tank (21), and the other end of the protrusion (232) away from the main body (231) is fixed to the other side of the asphalt tank (21). The top of the protrusion (232) is lower than the main body (231). The asphalt tank (21), the main body (231), and the protrusion (232) form the overflow gap (24).

7. The ammonia stripping system according to claim 1, characterized in that, The first asphalt filter (2) also includes a cover (25), which is sealed and removably placed on the asphalt tank (21).

8. The ammonia stripping system according to claim 1, characterized in that, The guide pipe (22) also includes a connecting section (221), one end of which is connected to the inlet end of the extension section (222), and the other end extends out of the asphalt box (21) and is connected to the ammonia stripping tower (1).

9. The ammonia stripping system according to claim 2, characterized in that, The ammonium sulfate unit also includes a desulfurizer (62), which is connected to the acid tar tank (61). The ammonia stripping system also includes a phenol-cyanide wastewater station (7), which is connected to the desulfurizer (62).

10. The ammonia stripping system according to claim 9, characterized in that, It also includes a third transfer pump (10), which is connected between the desulfurizer (62) and the phenol-cyanide wastewater station (7).

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