A system for treating the exhaust of a drying air of ammonium sulfate

Abstract

The utility model discloses an ammonium sulfate drying wind discharges end treatment system, including the vibration fluidized bed, be used for to the air blower, be connected in the ammonium sulfate stock bin of vibration fluidized bed tail lower extreme, set up the dust catcher in the vibration fluidized bed top, be located in the desulfurizing tower of vibration fluidized bed side, and discharge the air duct of leading; Dust catcher's material import and vibration fluidized bed's top exhaust port are connected through the pipeline, and the dust catcher bottom's collection place is connected with ammonium sulfate stock bin through the pipeline, dust catcher is connected with desulfurizing tower through discharging air duct and communicates, and desulfurizing tower still is connected with the desulfurizing tower air blower of being able to form negative pressure. In the technical scheme, the desulfurizing tower of negative pressure is used to absorb the dry air of dust catcher processing, can all be intercepted recovery with the ammonium sulfate of dry air entrainment, has solved the environmental pollution problem caused by the existing discharge end treatment not clean.

Description

Technical Field

[0001] This utility model relates to the field of steel manufacturing technology, and in particular to an end-of-pipe treatment system for ammonium sulfate drying air emissions. Background Technology

[0002] In the steel manufacturing industry, sintering processes generate large amounts of pollutants such as sulfur dioxide (SO2), nitrogen oxides (NOx), and dust. The ammonia method, as a recovery-based desulfurization method, can achieve a desulfurization efficiency of over 98%. Using ammonia water as an absorbent, it reacts with SO2 in the flue gas to generate (NH4)2SO4 solution. This solution is then passed through an ammonium sulfate preparation system, undergoing vacuum evaporation crystallization and centrifugal drying to obtain high-quality ammonium sulfate byproducts, offering significant economic benefits.

[0003] Ammonium sulfate crystals separated from the ammonium sulfate preparation system enter a vibrating fluidized bed in the ammonium sulfate drying unit. Hot air is then blown through the sieve holes on the fluidized bed surface to dry the ammonium sulfate. The waste drying hot air is then discharged. However, this drying hot air carries some ammonium sulfate powder, which needs to be intercepted and collected by a dust collector and returned to the ammonium sulfate silo. However, the dust collector cannot completely remove the powder; a small amount of ammonium sulfate remains in the final discharged drying air, causing environmental pollution. Therefore, improving the end-of-pipe treatment of ammonium sulfate drying air emissions to completely eliminate the ammonium sulfate powder carried in the final discharged drying air and avoid environmental pollution is a problem that needs to be solved. Utility Model Content

[0004] This utility model provides an end-of-pipe treatment system for ammonium sulfate drying air emissions, which solves the environmental pollution problem caused by the inability to completely remove ammonium sulfate powder entrained in the hot drying air in the prior art.

[0005] To achieve the above objectives, this utility model provides an end-of-pipe treatment system for ammonium sulfate drying air emissions, including a vibrating fluidized bed for drying the finished ammonium sulfate product, a blower for blowing air into the vibrating fluidized bed, an ammonium sulfate silo connected to the lower end of the vibrating fluidized bed, a dust collector installed above the vibrating fluidized bed, a desulfurization tower located on the side of the vibrating fluidized bed, and an exhaust duct; the material inlet of the dust collector is connected to the top exhaust port of the vibrating fluidized bed via a pipeline, and a material collection point is provided at the bottom of the dust collector, which is connected to the ammonium sulfate silo via a pipeline; the dust collector is connected to the desulfurization tower via the exhaust duct; the desulfurization tower is also connected to a desulfurization tower exhaust fan for forming negative pressure.

[0006] Furthermore, the blower includes a first blower and a second blower. The first blower is connected to the head of the vibrating fluidized bed, and the second blower is connected to the tail of the vibrating fluidized bed. A heater is also provided between the first blower and the head of the vibrating fluidized bed.

[0007] Furthermore, the desulfurization tower is equipped with a water washing spray layer, an absorption spray layer, and a concentration spray layer from top to bottom, and the output end of the exhaust duct is located between the concentration spray layer and the absorption spray layer.

[0008] Furthermore, a regulating valve is also installed in the exhaust duct.

[0009] Furthermore, the regulating valve is an electric valve.

[0010] Furthermore, the diameter of the exhaust duct is DN700~DN900.

[0011] Furthermore, the ammonium sulfate drying air emission end treatment system also includes a water washing tower installed in parallel with the desulfurization tower, with the inlet end of the water washing tower connected to the dust collector.

[0012] Furthermore, a shut-off valve and a water washing tower induced draft fan are connected between the water washing tower and the dust collector.

[0013] The above technical solution has the following beneficial effects:

[0014] In this technical solution, the dry air discharged from the dust collector is introduced into a negative pressure desulfurization tower. The desulfurization tower, which is not originally used for ammonium sulfate production, is used to complete the end-of-pipe treatment of the dry air emission. The multi-layer spray in the desulfurization tower is used to intercept the ammonium sulfate carried in the dry air, which prevents the escape of ammonium sulfate and avoids the situation where ammonium sulfate is carried in the final discharged dry air. This helps to improve the environment, eliminate air pollution, and avoid corrosion of surrounding buildings and equipment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of an end-of-pipe treatment system for ammonium sulfate drying air emissions according to an embodiment of this utility model;

[0017] Reference numerals: 1. Vibrating fluidized bed; 2. Dust collector; 3. Shut-off valve; 4. Water washing tower induced draft fan; 5. Water washing tower; 6. Water washing tower sprayer; 7. First blower; 8. Heater; 9. Second blower; 10. Ammonium sulfate silo; 11. Discharge induced draft pipe; 12. Regulating valve; 13. Desulfurization tower; 14. Concentration spray layer; 15. Absorption spray layer; 16. Water washing spray layer; 17. Drying air direction; 18. Ammonium sulfate to be dried; 19. Desulfurization tower induced draft fan. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] like Figure 1 As shown, this utility model embodiment provides an end-of-pipe treatment system for ammonium sulfate drying air emissions, including a vibrating fluidized bed 1 for drying finished ammonium sulfate, a blower for blowing air into the vibrating fluidized bed 1, an ammonium sulfate silo 10 connected to the lower end of the vibrating fluidized bed 1, a dust collector 2 disposed above the vibrating fluidized bed 1, a desulfurization tower 13 located on the side of the vibrating fluidized bed 1, and an exhaust duct 11; the material inlet of the dust collector 2 is connected to the top exhaust port of the vibrating fluidized bed 1 via a pipeline, and a material collection point is provided at the bottom of the dust collector 2, which is connected to the ammonium sulfate silo 10 via a pipeline; the top of the dust collector 2 is provided with a dust collector outlet, the input end of the exhaust duct 11 is connected to the dust collector outlet, and the output end of the exhaust duct 11 is connected to the desulfurization tower 13; the desulfurization tower 13 is also connected to a desulfurization tower exhaust fan 19 for forming negative pressure.

[0020] To address the aforementioned issues, this technical solution introduces the dry air discharged from the dust collector 2 into the desulfurization tower 13, a conventional component of the sintering production workshop, via the exhaust duct 11. This utilizes the desulfurization tower 13, which is not originally part of the ammonium sulfate drying unit, to assist in the final treatment of the dry air emissions. This technical solution ensures that a negative pressure (maintained no higher than -1100 Pa) is created inside the desulfurization tower 13 by the exhaust fan 19, enabling automatic ventilation. When the dry air discharged from the dust collector 2 is drawn into the desulfurization tower 13, the multi-layer spray system within the tower intercepts the ammonium sulfate carried in the dry air, forming a recoverable ammonium sulfate solution. This reduces or even completely eliminates the presence of ammonium sulfate in the final discharged dry air, thus reducing environmental pollution.

[0021] During this process, since the desulfurization tower 13 itself has sufficient desulfurization capacity, it will not affect the work that the desulfurization tower 13 itself is supposed to do.

[0022] Furthermore, a blower is used to input air into the vibrating fluidized bed 1, which then blows the ammonium sulfate 18 to be dried through the sieve holes on the surface of the vibrating fluidized bed 1, thereby achieving the air-drying effect. In application, two blowers can be used. The first blower 7 is connected to a heater 8 to blow hot air into the head of the vibrating fluidized bed 1, while the second blower 9 is used to blow cold air into the tail of the vibrating fluidized bed 1. This combination of hot and cold air can complete the air-drying process more quickly.

[0023] Furthermore, the desulfurization tower 13 is provided with a water washing spray layer 16, an absorption spray layer 15, and a concentration spray layer 14 from top to bottom, and the output end of the exhaust duct 11 is located between the concentration spray layer 14 and the absorption spray layer 15. Actual measurements show that the pressure below the concentration spray layer 14 inside the desulfurization tower 13 is approximately -700Pa to -800Pa, which does not meet the aforementioned negative pressure requirement (-1100Pa). If the exhaust duct 11 is introduced from this point, the suction force on the dry air discharged from the dust collector 2 will not achieve the expected effect. However, the pressure between the concentration spray layer 14 and the absorption spray layer 15 is -1400Pa to -1500Pa, which meets the suction force requirement. Therefore, it is preferable to connect the exhaust duct 11 below the absorption spray layer 15.

[0024] Furthermore, the exhaust duct 11 is also equipped with a regulating valve 12. When the desulfurization tower 13 is not required to participate in the end-of-pipe treatment of ammonium sulfate drying air, the desulfurization tower 13 can be isolated from equipment such as the dust collector 2 and the vibrating fluidized bed 1 by closing the regulating valve 12. In addition, when the desulfurization tower 13 participates in the end-of-pipe treatment of ammonium sulfate drying air, the opening of the regulating valve 12 can be adjusted during the production process to meet the actual needs.

[0025] Furthermore, to enable remote control and facilitate operation, the regulating valve 12 is an electric valve.

[0026] Furthermore, based on calculations and actual measurements, the diameter of the exhaust duct 11 should be controlled between DN700 and DN900.

[0027] Furthermore, the ammonium sulfate drying air emission end treatment system also includes a water washing tower 5 connected in parallel with the desulfurization tower 13. The inlet end of the water washing tower 5 is connected to the outlet of the dust collector. The water washing tower 5 is equipped with a water washing tower sprayer 6, which can also be used to treat the ammonium sulfate drying air. However, the water washing tower 5 usually has a small volume and limited processing capacity. Moreover, after using the water washing tower 5, due to its volume limitation, the drying air discharged from the water washing tower 5 may carry ammonium sulfate solution with it, thereby causing "drizzling" around the water washing tower 5 and causing corrosion damage to surrounding buildings and equipment. Therefore, in this technical solution, the water washing tower 5 is only used as a spare part of the desulfurization tower 13. The water washing tower 5 is only activated when the desulfurization tower 13 cannot be used under special circumstances.

[0028] Furthermore, a shut-off valve 3 and a water washing tower induced draft fan 4 are connected between the water washing tower 5 and the dust collector outlet. Since the water washing tower 5 serves only as a backup for the desulfurization tower 13, the shut-off valve 3 allows the branch line containing the water washing tower 5 to be shut off when the desulfurization tower 13 is operating, thus avoiding energy waste. When the desulfurization tower 13 requires inspection or maintenance, the regulating valve 12 can be closed, the shut-off valve 3 opened, and the water washing tower induced draft fan 4 turned on to draw in the dry air discharged from the dust collector 2 (the pressure at the inlet of the water washing tower induced draft fan 4 can reach -800Pa), thus putting the water washing tower 5 into operation. The shut-off valve 3 can also be an electric valve.

[0029] The present technical solution will be described in detail below with reference to a specific embodiment. The system configuration of this specific embodiment is described in [reference needed]. Figure 1 Its workflow is as follows:

[0030] The ammonium sulfate product separated from the ammonium sulfate preparation system (not shown in the figure) passes through a vibrating fluidized bed 1. It is blown into the bed surface of the vibrating fluidized bed 1 by a first blower 7 and a second blower 9 (a heater 8 is installed after the first blower 7, so hot air enters the head of the vibrating fluidized bed 1). The air passes through the bed surface sieve holes, blowing up the ammonium sulfate 18 to be dried, thus achieving an air-drying effect. Most of the dried ammonium sulfate is sent to the ammonium sulfate silo 10 located at the lower end of the vibrating fluidized bed 1. The blown-in drying air is drawn away by the negative pressure at the rear end, while some of the dried ammonium sulfate product is carried away in the drying air. Therefore, this carried-out ammonium sulfate product is intercepted when passing through a dust collector 2 (e.g., a cyclone dust collector), and then recovered to the ammonium sulfate silo 10 through the material pipe at the bottom collection point of the dust collector 2. However, dust collector 2 cannot recover all the ammonium sulfate product entrained in the drying air. Therefore, a small portion of the ammonium sulfate product will still be carried by the drying air and discharged from the dust collector outlet at the top of dust collector 2. It then enters the desulfurization tower 13 through the exhaust duct 11 and mixes with the sintering flue gas. After being treated by the absorption spray layer 15 and the water washing spray layer 16, all the ammonium sulfate powder can be effectively intercepted, converting the ammonium sulfate into a recyclable ammonium sulfate solution. This ensures that the drying air finally discharged from the top of the desulfurization tower 13 (see the drying air direction 17 in the figure) no longer contains ammonium sulfate, thus avoiding environmental pollution. Furthermore, due to the large volume and height of the desulfurization tower 13, the "dripping rain" situation of ammonium sulfate solution entrained during the drying air discharge that might occur with the water washing tower 5 can be avoided.

[0031] During the production process, the opening of regulating valve 12 should be adjusted appropriately (for example, to 60%). The purpose of this adjustment is to prevent most of the dry hot air from being directly sucked into the exhaust pipe 11 without cyclone dust removal due to excessive negative pressure of desulfurization tower 13, thus preventing dust collector 2 from functioning properly. Through reasonable opening adjustment and control, it can be ensured that all dry air is first treated by dust removal, and then the dust-treated dry air is drawn into desulfurization tower 13.

[0032] Meanwhile, in this application, the required drying air volume for the vibrating fluidized bed 1 is typically 60,000 m³ / h. 3 Approximately / h, compared to the 1.2 million m³ / h of sintering flue gas from desulfurization tower 13. 3 The throughput is negligible per hour, so it has no impact on the production of the desulfurization tower 13 itself.

[0033] In the above detailed description, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0034] The disclosed embodiments have been described above to enable any person skilled in the art to implement or use this invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not limited to the embodiments given herein, but is consistent with the widest scope of the principles and novel features disclosed in this application.

[0035] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A terminal treatment system for ammonium sulfate drying air emissions, characterized in that, The system includes a vibrating fluidized bed (1) for drying ammonium sulfate, a blower for blowing air into the vibrating fluidized bed (1), an ammonium sulfate silo (10) connected to the lower end of the tail of the vibrating fluidized bed (1), a dust collector (2) located above the vibrating fluidized bed (1), a desulfurization tower (13) located on the side of the vibrating fluidized bed (1), and an exhaust duct (11). The material inlet of the dust collector (2) is connected to the top exhaust port of the vibrating fluidized bed (1) through a pipeline. The bottom of the dust collector (2) is provided with a material collection point, which is connected to the ammonium sulfate silo (10) through a pipeline. The dust collector (2) is connected to the desulfurization tower (13) through the exhaust duct (11). The desulfurization tower (13) is also connected to a desulfurization tower exhaust fan (19).

2. The ammonium sulfate drying air emission end-of-pipe treatment system as described in claim 1, characterized in that, The blower includes a first blower (7) and a second blower (9). The first blower (7) is connected to the head of the vibrating fluidized bed (1), and the second blower (9) is connected to the tail of the vibrating fluidized bed (1). A heater (8) is also provided between the first blower (7) and the head of the vibrating fluidized bed (1).

3. The ammonium sulfate drying air emission end-of-pipe treatment system as described in claim 1, characterized in that, The desulfurization tower (13) is provided with a water washing spray layer (16), an absorption spray layer (15) and a concentration spray layer (14) from top to bottom. The output end of the exhaust duct (11) is located between the concentration spray layer (14) and the absorption spray layer (15).

4. The ammonium sulfate drying air emission end-of-pipe treatment system as described in claim 3, characterized in that, The exhaust duct (11) is also equipped with a regulating valve (12).

5. The ammonium sulfate drying air emission end-of-pipe treatment system as described in claim 4, characterized in that, The regulating valve (12) is an electric valve.

6. The ammonium sulfate drying air emission end-of-pipe treatment system as described in claim 1, characterized in that, The diameter of the exhaust duct (11) is DN700~DN900.

7. The ammonium sulfate drying air emission end-of-pipe treatment system as described in claim 1, characterized in that, It also includes a water washing tower (5) connected in parallel with the desulfurization tower (13), the inlet end of which is connected to the dust collector (2).

8. The ammonium sulfate drying air emission end-of-pipe treatment system as described in claim 7, characterized in that, A shut-off valve (3) and a water washing tower induced draft fan (4) are also connected between the water washing tower (5) and the dust collector (2).

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