Dry-process sodium-based desulfurization ash recycling system

Abstract

The utility model discloses a dry-method sodium-based desulfurization ash recycling system which comprises a desulfurization ash storage hopper, a water adding pipeline, a mixing pool, a first-stage reaction kettle, a hydrochloric acid dosing pipeline, a second-stage reaction kettle, a suction filter, an evaporation dryer, a wind type dryer, a sodium bicarbonate storage tank, a first heat exchanger, a nitrogen fertilizer storage tank, a second heat exchanger and an ammonium bicarbonate pipeline, an outlet of the desulfurization ash storage hopper is connected with a feeding port pipeline of the mixing pool, a water adding pipeline is connected with a water adding port of the mixing pool, an outlet of the mixing pool is connected with an inlet pipeline of the first-stage reaction kettle through the first-stage lifting pump, and an additive inlet of the first-stage reaction kettle is connected with a hydrochloric acid adding pipeline; an outlet of the first-stage reaction kettle is connected with an inlet pipeline of the second-stage reaction kettle, an additive inlet of the second-stage reaction kettle is connected with an ammonium bicarbonate pipeline, a lower-layer filtrate outlet of the second-stage reaction kettle is connected with an inlet pipeline of the first-stage reaction kettle through the second-stage lifting pump, and an upper-layer filtrate outlet of the second-stage reaction kettle is connected with an inlet pipeline of the suction filtration machine.

Description

Technical Field

[0001] This utility model relates to the field of desulfurization ash technology in industrial silicon production, specifically to a dry sodium-based desulfurization ash recycling system. Background Technology

[0002] Currently, there are many commonly used flue gas desulfurization (FGD) technologies both domestically and internationally. Based on the different desulfurization methods and product forms, FGD technologies can be divided into three main categories: wet, semi-dry, and dry. Dry FGD technology is increasingly used in small and medium-sized FGD systems, as it is technically mature and operates stably. Among these, the SDS sodium-based dry FGD process is the most widely used. The SDS dry FGD process uses sodium bicarbonate as the adsorbent for flue gas desulfurization. It removes acidic pollutants from the flue gas through chemical adsorption, and can also remove some organic and inorganic trace substances through physical adsorption. Sodium bicarbonate reacts directly with sulfur trioxide or sulfur dioxide in the flue gas to produce sodium sulfate and sodium sulfite, thereby achieving the purpose of desulfurization.

[0003] In recent years, the SDS dry desulfurization process, using sodium bicarbonate as the alkali source, has rapidly expanded its market share due to its advantages of high desulfurization efficiency, wide availability of desulfurizing agents, and low project implementation difficulty. It is currently widely used in ultra-low sulfur dioxide emission projects in ferrosilicon smelters, achieving excellent purification results. However, desulfurization ash is a soluble salt, and currently, most of its disposal relies on rigid landfill, resulting in high costs for enterprises and some environmental pollution, without establishing a recycling system for desulfurization ash. Utility Model Content

[0004] The purpose of this invention is to provide a dry sodium-based desulfurization ash recycling system.

[0005] This utility model is implemented by the following technical solution: a dry sodium-based desulfurization ash recycling system, which includes a desulfurization ash storage hopper, a water supply pipeline, a mixing tank, a primary reaction vessel, a hydrochloric acid dosing pipeline, a secondary reaction vessel, a filter press, an evaporator, a wind-type dryer, a sodium bicarbonate storage tank, a first heat exchanger, a nitrogen fertilizer storage tank, a second heat exchanger, and an ammonium bicarbonate pipeline.

[0006] The outlet of the desulfurization ash storage hopper is connected to the feed port pipeline of the mixing tank, the water supply pipeline is connected to the water supply port of the mixing tank, the outlet of the mixing tank is connected to the inlet pipeline of the primary reactor through a primary booster pump, and the additive inlet of the primary reactor is connected to the hydrochloric acid dosing pipeline.

[0007] The outlet of the primary reactor is connected to the inlet pipeline of the secondary reactor, the additive inlet of the secondary reactor is connected to the ammonium bicarbonate pipeline, the lower filtrate outlet of the secondary reactor is connected to the inlet pipeline of the primary reactor via a secondary booster pump, and the upper filtrate outlet of the secondary reactor is connected to the inlet pipeline of the vacuum filter.

[0008] The filtrate outlet of the vacuum filter is connected to the inlet pipeline of the evaporative dryer; the product outlet of the vacuum filter is connected to the inlet of the air dryer; the outlet of the air dryer is connected to the sodium bicarbonate storage tank; the gas outlet of the air dryer is connected to the inlet pipeline of the first heat exchanger; the condensate outlet of the first heat exchanger is connected to the inlet pipeline of the mixing tank; the material outlet of the evaporative dryer is connected to the inlet of the nitrogen fertilizer storage tank; the gas outlet of the evaporative dryer is connected to the inlet pipeline of the second heat exchanger; and the condensate outlet of the second heat exchanger is connected to the inlet pipeline of the mixing tank.

[0009] Furthermore, the outer wall of the mixing tank is provided with a water jacket.

[0010] Furthermore, the stirring gas inlet of the primary reactor and the stirring gas inlet of the secondary reactor are respectively connected to the flue gas pipeline.

[0011] Furthermore, the primary reaction vessel and the secondary reaction vessel are equipped with acid-base detectors.

[0012] Furthermore, filters are installed at the outlets of the primary reactor and the secondary reactor, respectively.

[0013] The advantages of this invention are: with the cooperation of a mixing tank, a primary reaction vessel, a secondary reaction vessel, an evaporator, and a pneumatic dryer, the desulfurization ash is reused, no solid waste is discharged, the recycling rate of desulfurization ash is increased, the nitrogen fertilizer produced is agricultural fertilizer that can be sold, and the sodium bicarbonate produced is used as a dry sodium-based desulfurizing agent. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0015] Figure 1 A schematic diagram of the structure of this utility model;

[0016] In the diagram: 1. Desulfurization ash storage hopper; 2. Mixing tank; 3. Water supply pipeline; 4. Primary booster pump; 5. Primary reactor; 6. Hydrochloric acid dosing pipeline; 7. Secondary reactor; 8. Ammonium bicarbonate pipeline; 9. Secondary booster pump; 10. Filter press; 11. Evaporator dryer; 12. Air dryer; 13. Sodium bicarbonate storage tank; 14. First heat exchanger; 15. Nitrogen fertilizer storage tank; 16. Second heat exchanger; 17. Water jacket; 18. Flue gas pipeline; 19. Acid-base detector; 20. Filter. Detailed Implementation

[0017] 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.

[0018] like Figure 1 As shown, the dry sodium-based desulfurization ash recycling system includes a desulfurization ash storage hopper 1, a water supply pipeline 3, a mixing tank 2, a primary reaction vessel 5, a hydrochloric acid dosing pipeline 6, a secondary reaction vessel 7, a filter press 10, an evaporator dryer 11, a pneumatic dryer 12, a sodium bicarbonate storage tank 13, a first heat exchanger 14, a nitrogen fertilizer storage tank 15, a second heat exchanger 16, and an ammonium bicarbonate pipeline 8.

[0019] The outlet of the desulfurization ash storage hopper 1 is connected to the feed port pipeline of the mixing tank 2, the water supply pipeline 3 is connected to the water supply port of the mixing tank 2, the outlet of the mixing tank 2 is connected to the inlet pipeline of the primary booster pump 4, and the additive inlet of the primary reactor 5 is connected to the hydrochloric acid dosing pipeline 6.

[0020] The outlet of the primary reactor 5 is connected to the inlet pipeline of the secondary reactor 7. The additive inlet of the secondary reactor 7 is connected to the ammonium bicarbonate pipeline 8. The lower filtrate outlet of the secondary reactor 7 is connected to the inlet pipeline of the primary reactor 5 via the secondary booster pump 9. The upper filtrate outlet of the secondary reactor 7 is connected to the inlet pipeline of the vacuum filter 10.

[0021] The filtrate outlet of the filter press 10 is connected to the inlet pipeline of the evaporator dryer 11. The product outlet of the filter press 10 is connected to the inlet of the air dryer 12. The outlet of the air dryer 12 is connected to the sodium bicarbonate storage tank 13. The gas outlet of the air dryer 12 is connected to the inlet pipeline of the first heat exchanger 14. The condensate outlet of the first heat exchanger 14 is connected to the inlet pipeline of the mixing tank 2. The material outlet of the evaporator dryer 11 is connected to the inlet of the nitrogen fertilizer storage tank 15. The gas outlet of the evaporator dryer 11 is connected to the inlet pipeline of the second heat exchanger 16. The condensate outlet of the second heat exchanger 16 is connected to the inlet pipeline of the mixing tank 2.

[0022] The outer wall of the mixing tank 2 is equipped with a water jacket 17 to meet the process temperature requirements during mixing and accelerate the mixing effect.

[0023] The stirring gas inlet of the primary reactor 5 and the stirring gas inlet of the secondary reactor 7 are respectively connected to the flue gas pipeline 18.

[0024] The primary reactor 5 and the secondary reactor 7 are equipped with acid-base detectors 19. The acid-base detectors 19 are used to detect the acidity and alkalinity of the reaction solution, and appropriate additives are added according to the acidity and alkalinity values.

[0025] The outlets of the primary reactor 5 and the secondary reactor 7 are respectively equipped with filters 20 to remove impurities.

[0026] With the cooperation of mixing tank 2, primary reaction vessel 5, secondary reaction vessel 7, evaporator dryer 11, and air dryer 12, the desulfurization ash was reused, zero solid waste was discharged, the recycling rate of desulfurization ash was increased, the nitrogen fertilizer produced is agricultural fertilizer that can be sold, and the sodium bicarbonate produced is used as a dry sodium-based desulfurizing agent.

[0027] The specific operation process of this embodiment is as follows:

[0028] S1. Add desulfurization ash and water to mixing tank 2 at a ratio of 1:3-5, with the water temperature above 25℃;

[0029] S2. The solution is lifted to the primary reactor 5 using the primary booster pump 4. The pH of the reaction solution is detected by the acid-base detector 19 in the primary reactor 5. Hydrochloric acid is added to the primary reactor 5 through the hydrochloric acid dosing line 6 to adjust the pH to 11-11.5. The treated flue gas is sent to the primary reactor 5 through the flue gas pipeline 18 to achieve the stirring function. The treated flue gas has a high carbon dioxide content and a high flue gas temperature, which can accelerate the reaction of carbon dioxide and sodium carbonate to produce sodium bicarbonate. The reaction time is 3-5 minutes. After a certain reaction time, the impurities are filtered out by the filter 20 at the outlet of the primary reactor 5 and then sent to the secondary reactor 7.

[0030] S3. In the secondary reactor 7, according to the acid-base value detected by the acid-base detector 19, add ammonium bicarbonate to the secondary reactor 7 at a ratio of 1:0.9 for desulfurization ash.

[0031] In S4, the treated flue gas is sent to the secondary reactor 7 via flue gas pipeline 18, and the reaction liquid is stirred for 10 to 30 minutes.

[0032] S5. The lower layer filtrate of the secondary reactor 7 is sent to the primary reactor 5 via the secondary booster pump 9, and the upper layer filtrate of the secondary reactor 7 is sent to the vacuum filter 10.

[0033] S6. The product of the filter press 10 enters the air dryer 12 at a temperature below 30 degrees Celsius. The product of the filter press 10 is sodium bicarbonate.

[0034] S7. The lower layer filtrate of the filter press 10 enters the evaporator dryer 11. The product of the evaporator dryer 11 is ammonium sulfate nitrogen fertilizer.

[0035] The condensate generated by S8, the air dryer 12, and the evaporator 11 is sent to the mixing tank 2 for reuse via the first heat exchanger 14 and the second heat exchanger 16, respectively.

[0036] 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, improvements, etc., 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. A dry sodium-based desulfurization ash recycling system, characterized in that, It includes a desulfurization ash storage hopper, water supply pipeline, mixing tank, primary reaction vessel, hydrochloric acid dosing pipeline, secondary reaction vessel, vacuum filter, evaporator dryer, air dryer, sodium bicarbonate storage tank, first heat exchanger, nitrogen fertilizer storage tank, second heat exchanger, and ammonium bicarbonate pipeline. The outlet of the desulfurization ash storage hopper is connected to the feed port pipeline of the mixing tank, the water supply pipeline is connected to the water supply port of the mixing tank, the outlet of the mixing tank is connected to the inlet pipeline of the primary reactor through a primary booster pump, and the additive inlet of the primary reactor is connected to the hydrochloric acid dosing pipeline. The outlet of the primary reactor is connected to the inlet pipeline of the secondary reactor, the additive inlet of the secondary reactor is connected to the ammonium bicarbonate pipeline, the lower filtrate outlet of the secondary reactor is connected to the inlet pipeline of the primary reactor via a secondary booster pump, and the upper filtrate outlet of the secondary reactor is connected to the inlet pipeline of the vacuum filter. The filtrate outlet of the vacuum filter is connected to the inlet pipeline of the evaporative dryer; the product outlet of the vacuum filter is connected to the inlet of the air dryer; the outlet of the air dryer is connected to the sodium bicarbonate storage tank; the gas outlet of the air dryer is connected to the inlet pipeline of the first heat exchanger; the condensate outlet of the first heat exchanger is connected to the inlet pipeline of the mixing tank; the material outlet of the evaporative dryer is connected to the inlet of the nitrogen fertilizer storage tank; the gas outlet of the evaporative dryer is connected to the inlet pipeline of the second heat exchanger; and the condensate outlet of the second heat exchanger is connected to the inlet pipeline of the mixing tank.

2. The dry sodium-based desulfurization ash recycling system according to claim 1, characterized in that, The outer wall of the mixing tank is equipped with a water jacket.

3. The dry sodium-based desulfurization ash recycling system according to claim 2, characterized in that, The stirring gas inlet of the primary reactor and the stirring gas inlet of the secondary reactor are respectively connected to the flue gas pipeline.

4. The dry sodium-based desulfurization ash recycling system according to claim 3, characterized in that, The primary reactor and the secondary reactor are equipped with acid-base detectors.

5. The dry sodium-based desulfurization ash recycling system according to claim 4, characterized in that, The outlets of the primary reactor and the secondary reactor are respectively equipped with filters.

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