Coal coking ammonia distillation and desulfurization combined system

Abstract

The utility model belongs to the technical field of coal gas purification, and particularly discloses a coal coking ammonia distillation and desulfurization combined system, which comprises an ammonia distillation tower, a desulfurization tower and an electrical tar precipitator, an ammonia gas pipeline of the ammonia distillation tower is communicated with a gas inlet pipeline of the electrical tar precipitator, a gas outlet pipeline of the electrical tar precipitator is communicated with the lower side of the desulfurization tower, and a gas outlet pipeline of the desulfurization tower is communicated with the lower side of the desulfurization tower. A spraying device is arranged in the desulfurizing tower, and the top of the desulfurizing tower is fixedly connected with an induced draft fan. According to the coke oven gas desulfurization device, gas ammonia generated in the ammonia distillation tower is mixed in coke oven gas to be desulfurized, the two gases are mixed and introduced into the electrical tar precipitator to remove organic impurities such as light tar and naphthalene, and then the gas enters the desulfurization tower to be desulfurized; the ammonia gas in the mixed gas can be used as an alkali source to supplement the alkali content of the desulfurization liquid in the desulfurization tower, and meanwhile, impurity components such as light tar and naphthalene in the ammonia gas generated by the ammonia distillation tower are prevented from entering a desulfurization system, so that the stable operation of the whole desulfurization device is ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of gas purification, and specifically relates to a combined ammonia distillation and desulfurization system for coal coking. Background Art

[0002] Coke oven gas is a product of coal coking, which can be used as industrial and civil gas and is also an important basic chemical raw material. Coke oven gas generally contains impurity gases such as hydrogen sulfide. If not removed, it will cause problems such as pipeline corrosion, subsequent catalyst poisoning, and environmental pollution. The wet desulfurization technology is a common choice for coke oven gas desulfurization at present. During the wet desulfurization process, the alkaline desulfurization liquid absorbs acidic gases such as hydrogen sulfide in the coke oven gas in the desulfurization tower, and a certain amount of alkali liquid needs to be supplemented irregularly to maintain the stability of the alkalinity and pH value of the desulfurization liquid.

[0003] During the coking process, residual ammonia water, a pollutant, is generated. To prevent the residual ammonia water from polluting the environment, it needs to be treated up to standard before being discharged. Ammonia distillation is an effective means for the pretreatment of residual ammonia water. The liquid ammonia or gaseous ammonia produced by the ammonia distillation tower can be used as an alkali liquid source to supplement the desulfurizer in the desulfurization tower. However, impurity components such as light tar and naphthalene contained in the residual ammonia water during the ammonia distillation process often enter the desulfurization system with the gaseous ammonia together, causing abnormal phenomena such as the sulfur foam in the desulfurization system becoming loose and the density of the desulfurization liquid increasing rapidly, which affects the stable operation of the desulfurization system. Therefore, it is necessary to design a combined ammonia distillation and desulfurization system for coal coking that can operate stably. Summary of the Utility Model

[0004] Aiming at the above technical problems, the utility model provides a combined ammonia distillation and desulfurization system for coal coking that can operate stably, so as to solve the problem that impurity components such as light tar and naphthalene are brought into the desulfurization system along with the gaseous ammonia, resulting in unstable operation of the desulfurization system.

[0005] To solve the above technical problems, the technical solution of the utility model is: a combined ammonia distillation and desulfurization system for coal coking, including an ammonia distillation tower and a desulfurization tower, and also including an electrostatic tar precipitator. The ammonia pipeline of the ammonia distillation tower is connected to the intake pipeline of the electrostatic tar precipitator, and the outlet pipeline of the electrostatic tar precipitator is connected to the lower side of the desulfurization tower. A spraying device is arranged in the desulfurization tower, and an induced draft fan is fixedly connected to the top of the desulfurization tower.

[0006] Further, the spraying device includes a spraying pipe and a circulating pump. The spraying pipe is provided with spray heads facing downward, and the spraying pipe is fixedly connected to the output end of the circulating pump through a liquid supply pipeline. The input end of the circulating pump is connected to the lower side of the desulfurization tower.

[0007] Further, a plate demister is installed in the upper part of the desulfurization tower.

[0008] Further, a flow regulating valve is installed on the ammonia pipeline of the ammonia distillation tower.

[0009] The utility model has the following advantages compared with the prior art:

[0010] 1. In the utility model, the gaseous ammonia generated in the ammonia distillation tower is mixed in the coke oven gas to be desulfurized. The two gases are mixed and introduced into an electrostatic tar precipitator to remove organic impurities such as light tar and naphthalene contained therein, and then enter a desulfurization tower for desulfurization treatment. The ammonia gas in the mixed gas can be used as an alkali source to supplement the alkali content of the desulfurization liquid in the desulfurization tower. At the same time, impurities such as light tar and naphthalene in the ammonia gas generated by the ammonia distillation tower are prevented from entering the desulfurization system, ensuring the stable operation of the entire desulfurization device.

[0011] 2. In the utility model, a plate demister is installed in the upper part of the desulfurization tower to remove the water mist in the desulfurized coke oven gas and prevent the desulfurized coke oven gas from containing water vapor; a flow regulating valve is installed on the ammonia gas pipeline to control the flow rate of the ammonia gas entering the electrostatic tar precipitator, avoiding excessive ammonia gas and resulting in ammonia gas impurities in the desulfurized coke oven gas, and further improving the product quality of the desulfurized coke oven gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic structural diagram of the utility model.

[0013] In the figure: 1. Ammonia distillation tower, 2. Desulfurization tower, 3. Electrostatic tar precipitator, 4. Ammonia gas pipeline, 5. Intake pipeline, 6. Outlet pipeline, 7. Induced draft fan, 8. Spray pipe, 9. Circulation pump, 10. Spray head, 11. Liquid supply pipeline, 12. Plate demister, 13. Flow regulating valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] The following will further illustrate the utility model in conjunction with the drawings.

[0015] As Figure 1 shown, a combined ammonia distillation and desulfurization system for coal coking includes an ammonia distillation tower 1 and a desulfurization tower 2. The bottom of the ammonia distillation tower 1 is fixedly connected with a surplus ammonia water inlet, a steam inlet, and an ammonia distillation treatment liquid outlet. It further includes an electrostatic tar precipitator 3. The ammonia gas pipeline 4 of the ammonia distillation tower 1 is communicated with the intake pipeline 5 of the electrostatic tar precipitator 3. The intake pipeline 5 is communicated with the coke oven gas supply pipeline. The outlet pipeline 6 of the electrostatic tar precipitator 3 is communicated with the lower side of the desulfurization tower 2. A spray device is arranged in the desulfurization tower 2. The top of the desulfurization tower 2 is fixedly connected with an induced draft fan 7.

[0016] It should be noted that the ammonia distillation tower is of an existing structure and will not be elaborated in this specification. In this embodiment, the ammonia gas pipeline 4 is connected to the ammonia gas outlet at the top of the ammonia distillation tower 1, and the gas passing through the ammonia gas pipeline 4 is uncooled gaseous ammonia. In this embodiment, the electrostatic tar precipitator 3 is a tubular electrostatic tar precipitator. In addition to the above-mentioned intake pipeline 5 and outlet pipeline 6, its structure also includes a tar discharge port fixedly connected to the lower side of the electrostatic tar precipitator 4. Inside the electrostatic tar precipitator 4, between the intake pipeline 5 and the outlet pipeline 6, a gas distribution plate, a hanger, and precipitation electrodes and corona electrodes installed between the hangers are sequentially arranged from bottom to top. The two electrodes are respectively connected to insulator boxes.

[0017] In order to increase the contact opportunity between the desulfurization liquid and the coke oven gas and completely remove hydrogen sulfide in the coke oven gas, the spraying device includes a spraying pipe 8 and a circulating pump 9. The spraying pipe 8 is equipped with downward-facing spray heads 10. The spraying pipe 8 is fixedly connected to the output end of the circulating pump 9 through a liquid supply pipeline 11. The input end of the circulating pump 9 is connected to the lower side of the desulfurization tower 2. By setting the circulating pump 9, the desulfurization liquid in the desulfurization tower 2 can be continuously recycled.

[0018] In order to remove the water mist in the coke oven gas after desulfurization is completed, a plate demister 12 is installed in the upper part of the desulfurization tower 2.

[0019] In order to facilitate the operator to adjust the supply amount of ammonia in real time and avoid ammonia mixing in the coke oven gas after desulfurization due to excessive ammonia, a flow regulating valve 13 is installed on the ammonia gas pipeline 4 of the ammonia distillation tower 1.

[0020] The specific working process of the present utility model is as follows:

[0021] Start the induced draft fan 7 and adjust the size of the flow regulating valve 13. The gaseous ammonia released from the ammonia distillation tower 1 enters the intake pipeline 5 through the ammonia gas pipeline 4, mixes with the coke oven gas, and then enters the electrostatic tar precipitator 3 under negative pressure. Under the treatment of the electrostatic tar precipitator 3, the tar droplets in the coke oven gas and impurity components such as light tar and naphthalene contained in the gaseous ammonia are separated. The tar and other impurities are discharged from the tar discharge port at the lower side of the electrostatic tar precipitator 3. The mixed gas of coke oven gas and ammonia enters the desulfurization tower 2 through the outlet pipeline 6 for desulfurization treatment. The circulating pump 9 continuously extracts the desulfurization liquid in the desulfurization tower 2 and pumps it into the spraying pipe 8, and then sprays it into the desulfurization tower 2 through the spray heads 10 for continuous circulation. When the desulfurization liquid needs to be replaced, turn off the circulating pump 9 and open the drain port at the lower side of the desulfurization tower 2 to discharge the waste liquid. Ammonia can supplement the alkaline substance content in the desulfurization liquid. The coke oven gas after desulfurization treatment passes through the plate demister 12 to remove the water mist and is discharged outside the desulfurization tower 2 through the induced draft fan 7 and enters the next process through the conveying pipeline.

Claims

1. A combined system for coal coking ammonia evaporation and desulfurization, comprising an ammonia evaporation tower (1) and a desulfurization tower (2), characterized in that: The desulfurization tower (2) further comprises an electric tar collector (3), wherein the ammonia pipeline (4) of the ammonia evaporation tower (1) is connected to the air inlet pipeline (5) of the electric tar collector (3), and the air outlet pipeline (6) of the electric tar collector (3) is connected to the lower side of the desulfurization tower (2). A spray device is provided in the desulfurization tower (2), and an induced draft fan (7) is fixedly connected to the top of the desulfurization tower (2).

2. The coal coking ammonia steam desulfurization combined system according to claim 1 is characterized in that: The spray device comprises a spray pipe (8) and a circulation pump (9); a spray head (10) facing downward is installed on the spray pipe (8); the spray pipe (8) is fixedly connected to the output end of the circulation pump (9) through a liquid supply pipe (11); and the input end of the circulation pump (9) is connected to the lower side of the desulfurization tower (2).

3. The coal coking ammonia steam desulfurization combined system according to claim 1 is characterized in that: A plate-type demister (12) is installed in the upper part of the desulfurization tower (2).

4. The coal coking ammonia steam desulfurization combined system according to claim 1, characterized in that: A flow regulating valve (13) is installed on the ammonia pipeline (4) of the ammonia distillation tower (1).

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