Waste ammonia gas recycling system

Abstract

The utility model discloses a waste ammonia gas recycling system which comprises a condensing tower, an ammonia gas absorption tower, an ammonia water storage tank and an ammonia desulfurization tower, a gas outlet of the condensing tower is communicated with an ammonia gas inlet of the ammonia gas absorption tower; a clear water tank is arranged at the bottom of the ammonia gas absorption tower, a produced water inlet is formed in the clear water tank, and the clear water tank is communicated with an ammonia absorption spraying pipe in the ammonia gas absorption tower through a clear water circulating pump; the clear water tank is communicated with the ammonia water storage tank; and the ammonia water storage tank is communicated with the ammonia desulfurization tower. According to the system, waste ammonia gas of the condensing tower is converted into ammonia water in the ammonia gas absorption tower, and then the ammonia water is used as a desulfurizing agent to be applied to an ammonia-process flue gas desulfurization process, so that deamination of exhaust gas of the condensing tower and desulfurization of sulfur-containing flue gas are realized, harmless emission of gas is realized, and any waste liquid, waste residue and waste gas CO2 are not generated in the process, and secondary pollution is avoided; the method also realizes treatment of wastes with wastes, reduces the ammonia water cost in the desulfurization process, can produce a desulfurization by-product ammonium sulfate, and has certain economic benefits.

Description

Technical field:

[0001] The utility model belongs to the technical field of ammonia treatment, and in particular relates to a waste ammonia recycling system. Background technology:

[0002] Evaporation and crystallization is the mainstream process in the zero-discharge treatment of industrial high-salinity wastewater. The evaporation and crystallization system can heat and evaporate the saline wastewater and separate it into sodium chloride, sodium sulfate, and miscellaneous salts. During the salt separation evaporation and crystallization process, the condensation tower of the evaporation and crystallization system will produce a large amount of non-condensable gas, the main components of which are waste ammonia and water vapor.

[0003] Direct emission of ammonia can burn human skin, eyes, and respiratory mucosa. Excessive inhalation can cause lung swelling or even death. Therefore, the ammonia discharged from the condensation tower of the evaporation crystallization system needs to be treated to avoid pollution caused by its emission. Utility model content:

[0004] The utility model aims to provide a waste ammonia recycling system, which can reuse the waste ammonia discharged from the condensation tower of the evaporation crystallization system in the flue gas desulfurization system, avoid the pollution of ammonia emission from the condensation tower, treat waste with waste, and reduce the operating cost of the flue gas desulfurization system.

[0005] The utility model is implemented by the following technical solutions:

[0006] A waste ammonia recycling system comprises a condensing tower, an ammonia absorption tower, an ammonia water storage tank, and an ammonia desulfurization tower; the gas outlet of the condensing tower is connected to the ammonia inlet of the ammonia absorption tower; a clean water tank is arranged at the bottom of the ammonia absorption tower, a water production inlet is opened on the clean water tank, a first liquid outlet of the clean water tank is connected to the water inlet of the ammonia absorption spray pipe in the ammonia absorption tower through a clean water circulation pump; the second liquid outlet of the clean water tank is connected to the water inlet of the ammonia water storage tank; the third liquid outlet of the ammonia water storage tank is connected to the ammonia water inlet of the ammonia desulfurization tower.

[0007] Since ammonia has high solubility, the ammonia gas discharged from the condensation tower in the evaporation crystallization system can be introduced into the ammonia absorption tower, and ammonia gas can be absorbed in the ammonia absorption tower by physical absorption, i.e., by spraying with water. The water produced by the reverse osmosis system of the water treatment front-end process can be introduced into the clean water tank to realize the resource recovery of low-concentration ammonia gas in the condensation tower of the evaporation crystallization system. This step processes the low-concentration ammonia gas into low-concentration ammonia water, realizes gas deammoniation, and does not cause negative effects such as environmental pollution and harm to the human body. The ammonia water produced by the ammonia absorption tower flows downward into the clean water tank, and when the ammonia water concentration in the clean water tank reaches 20%, the ammonia water is sent to the ammonia water storage tank.

[0008] Ammonia desulfurization uses ammonia water as an absorbent to react with sulfur dioxide and nitrogen oxides contained in industrial waste gas to remove waste gas and generate ammonium sulfate as a byproduct. In order to realize the resource utilization of ammonia water, the ammonia water in the ammonia water storage tank is transported to a power plant using a wet ammonia water desulfurization process, enters the ammonia desulfurization tower, and passes flue gas. The ammonia water in the ammonia desulfurization tower can absorb all the sulfur dioxide and nitrogen oxides in the flue gas pipeline and convert them into ammonium sulfate fertilizer. This process does not produce any waste liquid, waste residue and waste gas, and there is no secondary pollution. It meets the needs of the circular economy and enables the safe discharge of ammonia in the evaporation and crystallization workshop. At the same time, the ammonium sulfate formed can be utilized as a resource.

[0009] Furthermore, a pH sensor is provided on the clean water tank for detecting the pH value of the liquid in the clean water tank; a first ammonia delivery pump is connected between the second liquid outlet of the clean water tank and the water inlet of the ammonia storage tank, and a first control valve is provided between the clean water tank and the first ammonia delivery pump.

[0010] Furthermore, it also includes a pH interlock controller; the signal input end of the pH interlock controller is connected to the pH sensor signal, and the signal output end of the pH interlock controller is connected to the first control valve and the first ammonia water delivery pump. When the pH sensor detects that the pH of the liquid in the clean water tank is greater than 12.7, the pH interlock controller controls the first control valve to open and the first ammonia water delivery pump to operate, and delivers ammonia water to the ammonia water storage tank.

[0011] Furthermore, the ammonia water storage tank is provided with an ammonia water concentration monitor for detecting the ammonia water concentration in the ammonia water storage tank; a second ammonia water delivery pump is connected between the third liquid outlet of the ammonia water storage tank and the ammonia water inlet of the ammonia-based desulfurization tower, and a second control valve is provided between the ammonia water storage tank and the second ammonia water delivery pump; the fourth liquid outlet of the ammonia water storage tank is connected to the water inlet of the clean water tank through a third ammonia water delivery pump, and a third control valve is provided between the third ammonia water delivery pump and the clean water tank.

[0012] Furthermore, it also includes an ammonia concentration interlock controller; the signal input end of the ammonia concentration interlock controller is connected to the ammonia concentration monitor signal, and the signal output end of the ammonia concentration interlock controller is connected to the second control valve, the second ammonia delivery pump, the third control valve, and the third ammonia delivery pump. During the ammonia delivery process, the ammonia concentration will decrease due to volatilization. When the ammonia concentration monitor detects that the concentration of ammonia in the ammonia storage tank is greater than 20%, the ammonia concentration interlock controller controls the second control valve to open, the second ammonia delivery pump to run, the third control valve to close, and the third ammonia delivery pump to stop running, and the ammonia is delivered to the ammonia desulfurization tower for flue gas desulfurization; when the ammonia concentration monitor detects that the concentration of ammonia in the ammonia storage tank is less than 20%, the ammonia concentration interlock controller controls the second control valve to close, the second ammonia delivery pump to stop running, the third control valve to open, and the third ammonia delivery pump to run, and the ammonia is delivered to the clean water tank to continue to absorb ammonia gas and concentrate ammonia.

[0013] Furthermore, the ammonia absorption tower is provided with an exhaust port at the top, a demister is provided at the top, and a drain port connected to the clean water tank is provided at the bottom; a plurality of ammonia absorption spray pipes are provided in the ammonia absorption tower below the demister. The produced water in the clean water tank flows into the ammonia absorption spray pipe through the clean water circulation pump and then sprays out. The ammonia produced by the condensation tower enters the ammonia absorption tower, and the ammonia flows upward and is washed by the spray liquid flowing downward in a countercurrent manner, so that the ammonia and the spray liquid are fully in contact to achieve gas deammoniation. The deammonified gas continues to flow upward through the demister, and the demister separates the ammonia-containing water carried in the gas as much as possible, and then falls to the bottom of the ammonia absorption tower and finally enters the clean water tank. The demister can prevent the lack of ammonia water from causing the subsequent SO in the ammonia desulfurization tower. 2 The absorption is incomplete and at the same time the escape of excess ammonia can be prevented. The gas and air treated by the demister are discharged through the exhaust port at the top of the ammonia absorption tower.

[0014] Furthermore, the fifth liquid outlet at the lower part of the ammonia desulfurization tower is connected to the water inlet of the desulfurization spray pipe of the ammonia desulfurization tower through an ammonia water circulation pump; the desulfurization spray pipe is arranged at the upper part of the ammonia desulfurization tower; an exhaust port is provided at the top of the ammonia desulfurization tower; a flue gas inlet and an air inlet are provided at the ammonia desulfurization tower between the desulfurization spray pipe and the fifth liquid outlet. The ammonia water produced by the ammonia water storage tank enters the interior of the ammonia desulfurization tower, flows into the desulfurization spray pipe through the ammonia water circulation pump and then sprays out. The flue gas enters the ammonia desulfurization tower from the flue gas inlet and flows upward and is washed in a countercurrent manner by the spray liquid (ammonia water) flowing downward, so that the flue gas is fully contacted with the ammonia water, the sulfur dioxide and nitrogen oxides in the flue gas are fully absorbed by the ammonia water, and the desulfurized flue gas is discharged from the exhaust port at the top of the ammonia desulfurization tower, and the ammonia water and the acidic SO 2 A chemical reaction occurs to form ammonium sulfite; air enters the ammonia desulfurization tower from the air inlet, and the ammonium sulfite is oxidized to ammonium sulfate.

[0015] Furthermore, it also includes a cyclone, a centrifuge, and a dryer; the sixth liquid outlet at the bottom of the ammonia-based desulfurization tower is connected to the feed port of the cyclone through a mother liquid delivery pump; the product discharge port of the cyclone is connected to the feed port of the centrifuge; the sediment outlet of the centrifuge is connected to the feed port of the dryer. The ammonium sulfate generated in the ammonia-based desulfurization tower is delivered to the cyclone through the mother liquid delivery pump, and then enters the centrifuge and the dryer, and is processed in sequence to obtain a dried ammonium sulfate product.

[0016] Furthermore, a fan is connected between the gas outlet of the condensation tower and the ammonia inlet of the ammonia absorption tower, so as to transport the gas discharged from the condensation tower to the inside of the ammonia absorption tower.

[0017] Beneficial effects:

[0018] The utility model provides a waste ammonia recycling system, which processes the ammonia discharged from the condensation tower in the evaporation crystallization system through an ammonia absorption tower, empties the deammoniation gas, and uses ammonia water in an ammonia desulfurization tower to desulfurize flue gas. Ammonia water is used as an absorbent to react with sulfur dioxide and nitrogen oxides contained in industrial waste gas to remove waste gas and generate byproduct ammonium sulfate. It has the following advantages:

[0019] (1) Direct discharge of waste ammonia from the condensation tower of the evaporation crystallization system will cause varying degrees of harm to the human body. Recovering the waste ammonia and making it into ammonia water of a certain concentration can achieve safe discharge of ammonia in the evaporation crystallization workshop, greatly reducing the harm of ammonia to workshop workers;

[0020] (2) The waste ammonia gas from the condensing tower is converted into ammonia water and then used as a desulfurizer in the ammonia flue gas desulfurization process. Ammonia water can be used to remove sulfur dioxide, nitrogen oxides, etc. in the flue gas. This process does not produce any waste liquid, waste residue or waste gas CO during operation. 2 , there is no secondary pollution, and waste treatment is achieved, which meets the needs of circular economy and reduces desulfurization costs;

[0021] (3) The water produced by the reverse osmosis system of the front-end process of industrial saline wastewater treatment is used as the supplementary water of the clean water tank to absorb ammonia, so that the reverse osmosis water can be recycled without generating new water cost;

[0022] (4) This system produces ammonium sulfate as a desulfurization byproduct, which is a nitrogen fertilizer with excellent performance, high added value and a large application market. Selling it has certain economic benefits. Description of the drawings:

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a connection diagram of the waste ammonia recycling system in the embodiment;

[0025] Figure 2 It is the signal connection diagram of pH interlock controller;

[0026] Figure 3 This is the signal connection diagram of the ammonia concentration interlock controller.

[0027] The accompanying drawings are as follows:

[0028] 1. Condensation tower; 2. Fan; 3. Ammonia absorption tower; 4. Defogger; 5. Ammonia absorption spray pipe; 6. Clean water tank; 7. Clean water circulation pump; 8. pH sensor; 9. First control valve; 10. First ammonia delivery pump; 11. pH interlock controller; 12. Ammonia storage tank; 13. Ammonia concentration monitor; 14. Second control valve; 15. Second ammonia delivery pump; 16. Third control valve; 17. Third ammonia delivery pump; 18. Ammonia concentration interlock controller; 19. Ammonia desulfurization tower; 20. Desulfurization spray pipe; 21. Ammonia circulation pump, 22. Mother liquor delivery pump; 23. Cyclone; 24. Centrifuge; 25. Dryer. Specific implementation method:

[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. In the description of the utility model, it should be noted that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0030] Example

[0031] A waste ammonia recycling system, such as Figure 1 As shown, it includes a condensation tower 1, an ammonia absorption tower 3, an ammonia water storage tank 12, and an ammonia desulfurization tower 19.

[0032] The gas outlet of the condensation tower 1 is connected to the ammonia inlet of the ammonia absorption tower 3 through the fan 2. A clean water tank 6 is provided at the bottom of the ammonia absorption tower 3, a water production inlet is provided on the clean water tank 6, and a pH sensor 8 is provided on the clean water tank 6. An exhaust port is provided at the top of the ammonia absorption tower 3, a demister 4 is provided at the top, and a drain port connected to the clean water tank 6 is provided at the bottom; a plurality of ammonia absorption spray pipes 5 are provided in the ammonia absorption tower 3 below the demister 4. The first liquid outlet of the clean water tank 6 is connected to the water inlet of the ammonia absorption spray pipe 5 in the ammonia absorption tower 3 through the clean water circulation pump 7; the second liquid outlet of the clean water tank 6 is connected to the water inlet of the ammonia storage tank 12 through the first ammonia delivery pump 10, and a first control valve 9 is provided between the clean water tank 6 and the first ammonia delivery pump 10.

[0033] The ammonia storage tank 12 is provided with an ammonia concentration monitor 13; the third liquid outlet of the ammonia storage tank 12 is connected to the ammonia inlet of the ammonia desulfurization tower 19 through the second ammonia delivery pump 15, and a second control valve 14 is provided between the ammonia storage tank 12 and the second ammonia delivery pump 15. The fourth liquid outlet of the ammonia storage tank 12 is connected to the water inlet of the clean water tank 6 through the third ammonia delivery pump 17, and a third control valve 16 is provided between the third ammonia delivery pump 17 and the clean water tank 6.

[0034] like Figure 1 , Figure 2 As shown, it also includes a pH interlock controller 11; the signal input end of the pH interlock controller 11 is signal-connected to the pH sensor 8, and the signal output end of the pH interlock controller 11 is signal-connected to the first control valve 9 and the first ammonia delivery pump 10.

[0035] like Figure 1 , Figure 3As shown, it also includes an ammonia concentration interlock controller 18; the signal input end of the ammonia concentration interlock controller 18 is connected to the ammonia concentration monitor 13, and the signal output end of the ammonia concentration interlock controller 18 is connected to the second control valve 14, the second ammonia delivery pump 15, the third control valve 16, and the third ammonia delivery pump 17.

[0036] The fifth liquid outlet at the lower part of the ammonia desulfurization tower 19 is connected to the water inlet of the desulfurization spray pipe 20 of the ammonia desulfurization tower 19 through an ammonia water circulation pump 21; the desulfurization spray pipe 20 is arranged at the upper part of the ammonia desulfurization tower 19; an exhaust port is provided at the top of the ammonia desulfurization tower 19; a flue gas inlet and an air inlet are provided in the ammonia desulfurization tower 19 between the desulfurization spray pipe 20 and the fifth liquid outlet.

[0037] It also includes a cyclone 23, a centrifuge 24, and a dryer 25; the sixth liquid outlet at the bottom of the ammonia desulfurization tower 19 is connected to the feed port of the cyclone 23 through the mother liquor delivery pump 22; the product discharge port of the cyclone 23 is connected to the feed port of the centrifuge 24; the sediment outlet of the centrifuge 24 is connected to the feed port of the dryer 25.

[0038] Here’s how it works:

[0039] The waste ammonia and water vapor of the condensation tower 1 in the evaporation crystallization system enter the lower end of the ammonia absorption tower 3 through the fan 2. At the same time, the water produced by the reverse osmosis system enters the clean water tank 6, and enters the ammonia absorption spray pipe 5 through the clean water circulation pump 7 and then sprays downward. In the ammonia absorption tower 3, the ammonia flows upward and is washed in a countercurrent manner by the circulating slurry flowing downward, so that the gas and the liquid can be fully contacted to achieve gas deammoniation. The deammonified gas continues to flow upward through the demister 4, and the demister 4 separates the ammonia-containing water carried in the gas as much as possible, and then falls to the bottom of the ammonia absorption tower 3, and finally enters the clean water tank 6. The treated gas and air are discharged through the air outlet.

[0040] The pH value of the solution in the clean water tank 4 is detected by the pH sensor 8, and the detected pH data is transmitted to the pH interlock controller 11. When the pH value is greater than 12.7, the pH interlock controller 11 controls the operation of the first control valve 9 and the first ammonia delivery pump 10 to deliver the ammonia to the ammonia storage tank 12.

[0041] The ammonia concentration of the solution in the ammonia storage tank 12 is detected by the ammonia concentration monitor 13, and the detected ammonia concentration data is transmitted to the ammonia concentration interlock controller 18. During the ammonia delivery process, the ammonia concentration will decrease due to volatilization. When the ammonia concentration value is less than 20%, the ammonia concentration interlock controller 18 controls the third control valve 16 to open and the third ammonia delivery pump 17 to operate, and the ammonia is delivered to the clean water tank 6 to continue the cycle of absorbing ammonia gas to achieve ammonia concentration; when the ammonia concentration value is greater than 20%, the ammonia concentration interlock controller 18 controls the second control valve 14 to open and the second ammonia delivery pump 15 to operate, and the ammonia is delivered to the ammonia desulfurization tower 19 for desulfurization.

[0042] After the flue gas enters the ammonia desulfurization tower 19, 20% ammonia water enters the desulfurization spray pipe 20 through the ammonia water circulation pump 21 and then sprays downward. In the ammonia desulfurization tower 19, sulfur dioxide and nitrogen oxides in the flue gas flow upward and are washed in a countercurrent manner by the ammonia water circulation slurry flowing downward, so that the gas and liquid can fully contact and absorb sulfur dioxide and nitrogen oxides. Clean flue gas is discharged from the top of the ammonia desulfurization tower 19. At the same time, ammonia water and acid SO 2 A chemical reaction occurs to form ammonium sulfite, and after the air enters the ammonia desulfurization tower 19, the ammonium sulfite is oxidized to ammonium sulfate. The ammonium sulfate solution enters the cyclone 23 and the centrifuge 24 for separation through the mother liquor delivery pump 22, and finally enters the dryer 15 to form finished ammonium sulfate.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A waste ammonia recycling system, characterized in that: It includes a condensing tower, an ammonia absorption tower, an ammonia water storage tank, and an ammonia desulfurization tower; The gas outlet of the condensation tower is connected with the ammonia inlet of the ammonia absorption tower; a clean water tank is arranged at the bottom of the ammonia absorption tower, a water production inlet is opened on the clean water tank, a first liquid outlet of the clean water tank is connected with the water inlet of the ammonia absorption spray pipe in the ammonia absorption tower through a clean water circulation pump; the second liquid outlet of the clean water tank is connected with the water inlet of the ammonia water storage tank; the third liquid outlet of the ammonia water storage tank is connected with the ammonia water inlet of the ammonia desulfurization tower.

2. The waste ammonia recycling system according to claim 1, characterized in that: The clean water tank is provided with a pH sensor; a first ammonia delivery pump is connected between the second liquid outlet of the clean water tank and the water inlet of the ammonia storage tank, and a first control valve is provided between the clean water tank and the first ammonia delivery pump.

3. The waste ammonia recycling system according to claim 2, characterized in that: It also includes a pH interlock controller; the signal input end of the pH interlock controller is connected to the pH sensor signal, and the signal output end of the pH interlock controller is connected to the first control valve and the first ammonia delivery pump.

4. The waste ammonia recycling system according to claim 1, characterized in that: The ammonia water storage tank is provided with an ammonia water concentration monitor; a second ammonia water delivery pump is connected between the third liquid outlet of the ammonia water storage tank and the ammonia water inlet of the ammonia-based desulfurization tower, and a second control valve is provided between the ammonia water storage tank and the second ammonia water delivery pump; the fourth liquid outlet of the ammonia water storage tank is connected to the water inlet of the clean water tank through the third ammonia water delivery pump, and a third control valve is provided between the third ammonia water delivery pump and the clean water tank.

5. The waste ammonia recycling system according to claim 4, characterized in that: It also includes an ammonia concentration interlock controller; the signal input end of the ammonia concentration interlock controller is connected to the ammonia concentration monitoring meter signal, and the signal output end of the ammonia concentration interlock controller is connected to the second control valve, the second ammonia delivery pump, the third control valve, and the third ammonia delivery pump.

6. The waste ammonia recycling system according to claim 1, characterized in that: The top of the ammonia absorption tower is provided with an exhaust port, the upper part is provided with a demister, and the bottom is provided with a drain port connected to the clean water tank; a plurality of ammonia absorption spray pipes are arranged in the ammonia absorption tower below the demister.

7. The waste ammonia recycling system according to claim 1, characterized in that: The fifth liquid outlet at the lower part of the ammonia desulfurization tower is connected to the water inlet of the desulfurization spray pipe of the ammonia desulfurization tower through an ammonia water circulation pump; the desulfurization spray pipe is arranged at the upper part of the ammonia desulfurization tower; An exhaust port is provided at the top of the ammonia desulfurization tower; a flue gas inlet and an air inlet are provided at the ammonia desulfurization tower between the desulfurization spray pipe and the fifth liquid outlet.

8. The waste ammonia recycling system according to claim 1, characterized in that: It also includes a cyclone, a centrifuge, and a dryer; the sixth liquid outlet at the bottom of the ammonia desulfurization tower is connected to the feed port of the cyclone through a mother liquid delivery pump; the product discharge port of the cyclone is connected to the feed port of the centrifuge; the sediment outlet of the centrifuge is connected to the feed port of the dryer.

9. The waste ammonia recycling system according to claim 1, characterized in that: A fan is connected between the gas outlet of the condensation tower and the ammonia inlet of the ammonia absorption tower.

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