CN204220010U - The device of nitrogen oxide is removed in process of coking - Google Patents

Abstract

The utility model relates to a device for removing nitrogen oxides in the coking process. The high-temperature flue gas discharged from the combustion chamber of the device directly injects ammonia into the heat storage chamber of the coke oven, and a selective non-catalytic reduction reaction occurs to remove a part of nitrogen. Oxides; using the stacked structure of bricks in the regenerator, the flue gas moves in a turbulent manner to fully mix the unreacted nitrogen oxides and ammonia, and remove part of the nitrogen oxides; the temperature of the flue gas after passing through the regenerator decreases After reaching an appropriate temperature, it passes through the catalyst bed, and a selective catalytic reduction reaction occurs to further remove nitrogen oxides in the flue gas. Through the above three-stage treatment, the nitrogen oxides in the flue gas are reduced to non-toxic and harmless nitrogen, so as to achieve the discharge of nitrogen oxides in the coke oven exhaust gas up to the standard.

Description

A device for removing nitrogen oxides during coking

technical field

The utility model relates to a denitrification device for coking waste gas, which is mainly used for purification treatment of nitrogen oxide-containing waste gas produced in the coking industry.

Background technique

While today's coking industry meets the ever-increasing material needs of human beings, it also causes a large consumption of resources and energy, which brings serious pollution to the natural environment and severely damages the environment on which human beings depend for survival.

Tamping coking is a high-energy-consuming industry, which not only consumes a lot of energy, but also causes serious pollution. my country's coking industry has a long history of development, but the pollution control of this industry has not been paid enough attention, especially the pollution problem of nitrogen oxides in coke ovens has not been resolved. In the "Coking Chemical Industry Pollutant Discharge Standard" that was implemented in 2012, it is stipulated that the nitrogen oxide emission concentration of newly built coke ovens after 2015 shall not exceed 500 mg/m ³ , while the maximum emission concentration of nitrogen oxide in the thermal power industry is 100 mg /m ³ . To achieve the above goals, effective control measures must be taken to reduce the emissions of nitrogen oxides produced in the coking process.

Contents of the invention

In order to solve the problem of excessively high emission concentration of nitrogen oxides produced in the coking process, the purpose of this utility model is to provide a device for removing nitrogen oxides in the coking process, which is used to purify and treat the nitrogen oxides produced during the operation of coke ovens in coking enterprises. Exhaust gas of nitrogen oxides.

The purpose of this utility model is to realize by following technical method:

A device for removing nitrogen oxides in the coking process, which is composed of an ammonia production system, an ammonia gas control system, an ammonia gas nozzle, a coke oven regenerator, a branch flue at the bottom of the regenerator, a main flue, a catalyst bed and a chimney . The flue gas containing nitrogen oxides is generated from the top combustion chamber of the coke oven and enters the coke oven regenerator directly through the chute below the combustion chamber. In the regenerator chamber of the furnace, the ammonia gas produced by the ammonia production system is regulated by the ammonia gas control system. The coke oven regenerator chamber is neatly arranged with lattice bricks and grate bricks. The ammonia nozzle is set between the two air inlets of the ammonia gas control system. The gas is discharged from the branch flue at the bottom of the coke oven regenerator and enters the main flue. The flue gas is fully mixed with the injected ammonia gas. The mixed gas passes through the catalyst bed installed inside the flue, and the nitrogen in the flue gas is catalyzed. The oxide reacts with ammonia to reduce the nitrogen oxides in the flue gas to non-toxic and harmless nitrogen and water, and the purified flue gas is discharged from the chimney.

The utility model has the advantages of:

The utility model mainly uses the SCR/SCNR combined denitrification technology in the regenerator and the flue of the coking equipment, and purifies the nitrogen oxides in the flue gas through three stages. In the first stage, ammonia is directly injected into the high-temperature flue gas discharged from the combustion chamber in the regenerator of the coke oven, and a selective non-catalytic reduction reaction occurs to remove a part of nitrogen oxides; The characteristics of the mode movement make the unreacted nitrogen oxides and ammonia fully mixed; the temperature of the flue gas after passing through the regenerator in the third stage is reduced to an appropriate temperature, and then passes through the catalyst bed, and a selective catalytic reduction reaction occurs to further remove the flue gas. of nitrogen oxides. Through the above three-stage treatment, the nitrogen oxides in the flue gas are reduced to non-toxic and harmless nitrogen, so as to achieve the discharge of nitrogen oxides in the coke oven exhaust gas up to the standard.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

Below in conjunction with accompanying drawing, the technical scheme of this device is described further:

As shown in Figure 1, a device for removing nitrogen oxides in the coking process is composed of an ammonia production system 1, an ammonia gas control system 2, an ammonia gas nozzle 3, a coke oven regenerator 4, and a branch flue at the bottom of the regenerator 5. The main flue 6, the catalyst bed 7 and the chimney 8 are composed. The flue gas containing nitrogen oxides is generated from the top combustion chamber of the coke oven and enters the coke oven regenerator 4 directly through the chute below the combustion chamber. The top is sprayed into the regenerator 4 of the coke oven. At this time, the temperature of the flue gas is about 1000°C. The ammonia gas is generated by the ammonia production system 1 and sprayed into the regenerator 4 from the top of the regenerator 4 through the ammonia nozzle 3 . The injection amount of ammonia gas and which group of regenerators are injected are automatically controlled by the ammonia gas control system 2 . The ammonia nozzle 3 is arranged between the two air inlets of the ammonia gas control system 2, which is designed so that the flue gas containing nitrogen oxides can be mixed with the injected ammonia gas as soon as it enters the regenerator 4. An SNCR reaction occurs. After the flue gas and ammonia gas are initially mixed, they enter the checker bricks in the regenerator 4 for heat exchange, and the SNCR reaction can continue until the temperature of the flue gas drops to 850°C.

Checker bricks are neatly arranged in the heat storage chamber, and the checker bricks are the main structure for heat storage and flue gas mixing. The flue gas conducts heat to the bricks through the bricks, so as to increase the temperature of the flue gas in the regenerator 4 of the coke oven, so as to achieve the purpose of heat storage. Since the coke oven regenerator 4 has a brick-stacked structure, the flue gas flows in a turbulent flow in the coke oven regenerator 4. Oxides and ammonia are fully mixed to remove part of nitrogen oxides;

A branch flue is installed at the bottom of each regenerator, and all the branch flues finally converge with the main flue. The flue gas is discharged from the branch flue 5 at the bottom of the coke oven regenerator 4, and then enters the main flue 6. At this time, the temperature of the flue gas passing through the coke oven regenerator 4 for heat exchange is 300 degrees Celsius. The flue gas is fully mixed with the injected ammonia gas, and the mixed gas passes through the catalyst bed 7 installed inside the flue. The catalyst bed 7 is installed in a section of the main flue 6 where the temperature is suitable for reaction. The catalyst is a mixture of TiO ₂ and V ₂ O ₅ Mixed material, TiO ₂ is used as the skeleton material. The catalyst material is a honeycomb square column with a height of 1m. The cross section of the catalyst column is 5×5 square holes evenly arranged, and the wall thickness of the square hole is 1mm. Nitrogen oxides in the flue gas react with ammonia after catalytic reaction, so that the nitrogen oxides in the flue gas are reduced to non-toxic and harmless nitrogen and water, and the purified flue gas is discharged from the chimney 8 .

Claims (1)

1. A device for removing nitrogen oxides in the coking process, which consists of an ammonia production system (1), an ammonia gas control system (2), an ammonia gas nozzle (3), a coke oven regenerator (4), and a regenerator Bottom branch flue (5), main flue (6), catalyst bed (7) and chimney (8), flue gas containing nitrogen oxides is generated from the top combustion chamber of the coke oven and enters directly through the chute below the combustion chamber In the coke oven regenerator (4), the ammonia gas produced by the ammonia production system (1) is sprayed into the coke oven regenerator (4) from the top of the coke oven regenerator (4) through the ammonia nozzle (3) to produce ammonia The ammonia gas generated by the system (1) is regulated by the ammonia gas control system (2). The coke oven regenerator (4) is neatly arranged with grid bricks and grate bricks. The ammonia nozzle (3) is set on both sides of the ammonia gas control system (2). Between the two inlets, the flue gas is discharged from the branch flue (5) at the bottom of the coke oven regenerator (4) and enters the main flue (6). The flue gas is fully mixed with the injected ammonia gas, and the mixed gas Through the catalyst bed (7) installed inside the flue, the nitrogen oxides in the flue gas react with ammonia after catalytic reaction, so that the nitrogen oxides in the flue gas are reduced to non-toxic and harmless nitrogen and water, and the purification is completed The flue gas is discharged from the chimney (8).