KR101476404B1 - Method for treating scrapped ammonia and system thereof, and ammonia injection system of denitrification apparatus - Google Patents

Abstract

The present invention relates to a method for treating waste ammonia, a system thereof, and an ammonia injection system of a denitrification apparatus including the same, wherein the method for treating waste ammonia comprises a step of converting waste ammonia into waste ammonia water to collect (S11); a step of atomizing the waste ammonia water (S13); and a step of injecting the atomized waste ammonia water to a denitrification reactor to be used as a reductant of the denitrification reactor (S15). The present invention recycles waste ammonia as a reductant of a denitrification reactor, thereby preventing the loss of expensive reductants. The waste ammonia is atomized to be injected to the denitrification reactor, and, therefore, the waste ammonia water is uniformly injected to the denitrification reactor without a separate evaporating means so as to increase the utilization rate of the waste ammonia.

Description

TECHNICAL FIELD The present invention relates to a waste ammonia treatment method, a waste ammonia treatment system, and an ammonia injection system for a denitrification reaction apparatus including the same. BACKGROUND ART [0002]

The present invention relates to a waste ammonia treatment method, a waste ammonia treatment system, and an ammonia injection system of the denitrification reactor including the same. More particularly, the present invention relates to an ammonia injection system for removing waste ammonia from a denitrification reactor, An ammonia treatment method, a waste ammonia treatment system, and an ammonia injection system of a denitrification reactor including the same.

In a large-scale combustion device such as a power plant, a boiler, and an incinerator, a selective catalytic reduction (SCR) method is operated to reduce nitrogen oxides (NOx) generated when fossil fuels are burned, and ammonia is used as a reducing agent.

For example, ammonia is used as a reducing agent in a large-capacity combustion device equipped with a denitration reactor, which is a selective catalytic reduction (SCR) facility, and anhydrous ammonia is supplied to a denitration reactor through an air mixer through a storage tank, an evaporator, .

At this time, a certain amount of waste ammonia is generated during the operation of the plant, and the waste ammonia is absorbed and stored in the absorption tank. Since ammonia has good solubility in water, the amount of waste ammonia stored in the absorption tank is concentrated by the lung cancer concentration of 25% or less, and then it is sent to the wastewater treatment plant through the transfer pump and the pipeline.

In addition, in a power plant or a chemical plant using ammonia as a raw material and a reactant, waste ammonia is generated during operation of the apparatus, and the generated ammonia is transferred to a wastewater treatment plant together with other waste liquid to neutralize the waste, It is true.

On the other hand, anhydrous ammonia is dangerous material and it is a serious accident-causing material in terms of environmental and safety management when it spills out because it is toxic.

Therefore, unlike large-scale domestic power plants in foreign countries, ammonia water is used as a reducing agent for denitrification reactors early in the case of new power plants due to safety and handling problems. In recent years, ammonia has been gradually changed to ammonia water Trend.

However, in order to use the liquid ammonia water as the reducing agent, a transfer pump, an evaporator, a mixing air and an injection mode are required, and auxiliary facilities for evaporating ammonia water such as an auxiliary steam heat exchanger and a heating power source are required.

Therefore, there has been an attempt to improve the pre-evaporation effect of urea and ammonia water, which are liquid denitrification reducing agents, in a denitrification reactor, and a reaction chamber in which a combustion exhaust gas having a high temperature of 300 to 500 캜 passes is disposed downstream of the combustion apparatus. And then supplied to the denitration reactor through a duct. (Patent Document 1)

However, although the method of Patent Document 1 has an advantage of evaporating the liquid denitrification reducing agent, since the ammonia evaporated due to the injected injection nozzle and the duct drift can not be uniformly introduced into the denitration reactor, the utilization of the reducing agent is lowered There is a problem.

1. Domestic Patent Publication No. 10-0739124 (Registered Date: 2007.06.06, Name: Nitrogen Oxidation Reduction System Using Selective Catalytic Reduction Method)

Therefore, it is an object of the present invention to provide a method and an apparatus for recycling waste ammonia generated in the process by recycling the waste ammonia to a denitrification reaction apparatus, not an apparatus for treating wastewater, by using anhydrous ammonia or ammonia water as a reducing agent in the denitrification reactor, An ammonia treatment method, a waste ammonia treatment system, and an ammonia injection system of a denitration reaction apparatus including the same.

According to an aspect of the present invention for achieving the above object, the present invention provides a method for purifying waste ammonia comprising the steps of: a) converting waste ammonia into waste ammonia water and collecting b) atomizing the waste ammonia water, c) And injecting waste ammonia water into the denitration reactor to use the waste ammonia water as a reducing agent in the denitrification reactor.

In the step a), the waste ammonia is generated from the denitrification reactor or the ammonia storage facility.

In the step a), the waste ammonia is absorbed with water and converted into waste ammonia water having a concentration of 25% or less.

In step b), the waste ammonia water is atomized using a Venturi atomizer or an ultrasonic atomizer.

In the step c), the atomized waste ammonia water is injected into the denitrification reactor with the volume ratio of ammonia to air being less than 5% by using an air injection equipment.

An ammonia dissolving tank for converting ammonia discharged from the ammonia and ammonia storage facilities generated in the denitrification reaction apparatus into waste ammonia water and storing the nitrogen oxides contained in the combustion gas in contact with ammonia; And an air injection unit for supplying air to the atomized waste ammonia water to inject ammonia into the denitration reactor so that the volume ratio of ammonia to air is less than 5%.

Wherein the atomizing means comprises: a venturi pipe having a discharge port connected to an injection nozzle provided in the denitrification reaction device and having a cross-sectional area of a portion of the pipe reduced, and a venturi pipe communicating with an inlet of the venturi pipe, Lt; RTI ID = 0.0 > Venturi < / RTI >

The Venturi tubes are installed in multiple parallel.

The ratio of the cross-sectional area of the through-neck portion of the venturi tube to the cross-sectional area of the outlet is 1: 6-8.

The atomizing means is an ultrasonic atomizer using an ultrasonic vibrator.

An ammonia storage facility for storing ammonia to be injected into the denitrification reaction device; and an ammonia storage device for storing waste ammonia generated in the denitrification reaction device and the ammonia storage device An ammonia dissolution tank for converting the ammonia discharged from the ammonia storage facility into waste ammonia water and storing the waste ammonia water stored in the ammonia storage facility and selectively supplying the waste ammonia water stored in the ammonia dissolution tank to the denitrification reaction device do.

An atomizing unit for atomizing the waste ammonia water before the waste ammonia water is injected into the denitrification reactor, and an air injection unit for supplying air to the atomized waste ammonia water and mixing the waste ammonia water.

A nitrogen oxide concentration sensor provided at the combustion gas outlet side of the denitrification apparatus for measuring the concentration of nitrogen oxide discharged through the combustion gas outlet; a nitrogen oxide concentration sensor provided in the ammonia dissolution tank for detecting the concentration of the waste ammonia water Wherein the supply adjusting means selectively supplies the ammonia stored in the ammonia storage facility or the waste ammonia water stored in the ammonia dissolution tank to the ammonia storage tank in accordance with the measurement result of the nitrogen oxide concentration sensor and the waste ammonia concentration sensor, To be injected into the denitration reactor.

The waste ammonia generated in the denitration reactor is recycled to the denitrification reactor instead of the wastewater treatment unit and recycled as a reducing agent for the denitrification reactor, thereby preventing the loss of expensive reductant.

Further, since the ammonia leaking from the ammonia storage facility is collected and recycled, the diffusion damage due to ammonia leakage can be prevented, and thus the utilization system of waste ammonia can be safely prevented and environmental pollution can be prevented.

In addition, since the present invention converts waste ammonia into ammonia water, atomizes it, and mixes it with air and injects it into the denitration reactor, the waste ammonia water is uniformly injected into the denitrification reactor without additional evaporation means, Can be increased.

Further, according to the present invention, the supply control means selectively injects ammonia stored in the waste ammonia and ammonia storage facilities into the denitration reactor according to the concentration of the waste ammonia and the nitrogen oxide, so that the denitrification efficiency of the denitrification reactor can be uniformly maintained It is effective.

1 is a schematic view showing a preferred embodiment of an ammonia injection system of a waste ammonia treatment method, a waste ammonia treatment system and a denitrification reactor including the same, according to the present invention.
2 is a view showing a denitration reaction apparatus according to the present invention.
3 and 4 are views showing a Venturi sprayer according to an embodiment of the present invention.
5 and 6 are views showing an ultrasonic imaging apparatus according to an embodiment of the present invention.
7 is a flowchart showing a method of treating waste ammonia according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The waste ammonia treatment method of the present invention recycles waste ammonia generated from a denitration reactor 30 and a ammonia storage facility, which are selective catalytic reduction (SCR) facilities in a large-capacity combustion apparatus, as a reducing agent in the denitrification reactor 30.

The large-scale combustion device may be a coal-fired power plant.

1, the coal power plant is a power plant that converts heat generated by burning coal in the combustion apparatus 10 into electrical energy. The combustion gas generated in the combustion apparatus 10 recovers heat through the absorbent unit 20 and the air preheater 40 and is discharged to the atmosphere through the final stack 70.

The combustion process of coal generates pollutants such as sulfur dioxide (SO ₂ ), nitrogen oxides (NO x) and dust. In order to remove such contaminants, a denitration reactor 30, an electrostatic precipitator 50, and a desulfurization facility 60, which is a desulfurization facility, are installed and operated in a large-scale combustion apparatus.

The denitration reactor 30 uses ammonia as a reducing agent. The liquefied anhydrous ammonia or ammonia water is received from the tank and stored in the ammonia storage facility 80. The gas ammonia is supplied to the air injection equipment 110 through the evaporator 90 and the regulator 100, Is mixed with air in the mixer 120 and then injected into the denitration reactor 30.

When the gaseous ammonia is injected into the denitration reactor 30, the volume ratio of ammonia to air is adjusted to 5% or less to prevent ammonia from exploding. The explosion range of ammonia is 16-27% by volume of ammonia / air.

The denitration reactor 30 has a combustion gas inlet port 31 formed at one side thereof and a combustion gas outlet port 33 formed at the other side thereof. The denitrifying reaction apparatus 30 includes a plurality of injection nozzles formed in the injection line 35 and the injection line 35 so as to uniformly inject ammonia therein. The injection nozzle 37 means a thin tube provided on the injection line for jetting the liquid or gas into the free space at a high speed.

The ammonia injected into the denitration reactor 30 converts a large amount of nitrogen oxides contained in the combustion gas into nitrogen and water vapor to reduce nitrogen oxides, and the unreacted ammonia is discharged through the discharge pipe 39. The waste ammonia discharged through the discharge pipe (39) is collected in the waste ammonia collecting means (130).

The waste ammonia also originates from the ammonia storage facility 80. The ammonia storage facility 80 discharges a large amount of ammonia in the piping purge process at the time of unloading the tank, and the ammonia is collected in the effluent ammonia collection means 140.

Ammonia purged into the ammonia storage facility 80 may be anhydrous ammonia or ammonia water. Anhydrous ammonia is treated as a high-pressure gas, toxic and dangerous material, which has a significant impact on the environment and safety in the event of a massive spill. Therefore, it is preferable that the effluent ammonia collecting means 140 is collected and reused.

The waste ammonia collected in the waste ammonia collecting means 130 and the discharged ammonia collecting means 140 is recycled to the denitrification reactor 30, not the wastewater treatment apparatus, to be recycled as a reducing agent.

1 and 7, a) converting the waste ammonia into waste ammonia water to recover (S11), b) atomizing the waste ammonia water (S13), c) And injecting waste ammonia water into each injection nozzle of the denitrification reactor to use the waste ammonia water as a reducing agent in the denitrification reactor 30 (S15).

In step a), the waste ammonia is waste ammonia collected from the denitration reactor 30 or the ammonia storage facility 80 and collected in the waste ammonia collection means 130 and the outflow ammonia collection means 140.

The waste ammonia collected in the waste ammonia collecting means 130 and the flowing ammonia collecting means 140 is converted into waste ammonia water in the ammonia dissolving tank 150 and stored.

The ammonia dissolving tank 150 absorbs the waste ammonia with water and stores the waste ammonia water at a final concentration of 25% or less. The ammonia dissolution tank 150 is provided with a waste ammonia water concentration sensor 151 for detecting the concentration of the waste ammonia water. The concentration information of the waste ammonia water detected by the waste ammonia water concentration sensor 151 is transmitted to the supply adjusting means 190.

In step b), the waste ammonia water is transferred to the ammonia water injection tank 160 disposed adjacent to the denitration reactor 30 through the transfer pump 155. The ammonia dissolving tank 150 is connected to the ammonia water injection tank 160 through a supply pipe 153. A transfer pump 155 is installed in the supply pipe 153 to transfer the waste ammonia water to the ammonia water injection tank 160 And the feed amount can be adjusted.

The waste ammonia transferred to the ammonia water injection tank 160 is atomized using the atomization means 170. Before the waste ammonia water is injected into the reducing agent of the denitrification reactor 30, atomization (atomization) of the waste ammonia water is necessary to facilitate the evaporation. The atomization of the waste ammonia water can be realized by using the atomization means 170.

The atomization means 170 is preferably a Venturi atomizer 171 or an ultrasonic atomizer 181.

2 to 4, the Venturi sprayer 171 includes a venturi tube 172 having an outlet 173 and an inlet 175 and a portion of the passageway 177 that reduces the cross- And an inlet pipe 179 communicating with the inlet of the venturi pipe 172.

The discharge port 173 of the venturi pipe 172 is connected to the injection line 35 of the denitrification reaction device 30 and passes through the pipeline of the venturi pipe 172 so that the atomized waste ammonia water flows into the denitration reaction device 30 Can be injected.

Waste ammonia water and air flow into the inlet pipe 179. The waste ammonia water flows through the ammonia water injection tank 160 connected to the inlet pipe 179. The air is introduced into the inflow pipe 179 through the air injection equipment 110 and then moved to the plurality of venturi pipes 172 arranged in multiple parallel and mixed with the waste ammonia water while moving to the venturi pipe 172.

The air flowing into the inlet pipe 179 is mixed with the waste ammonia water to adjust the volume ratio of ammonia to air to 5% or less. The adjustment of the volume ratio of ammonia to air is intended to prevent ammonia from exploding.

The principle is that if the air flow by the air from the air injection equipment 110 flows into the inflow pipe 179, the airflow passes through the passing neck portion of the venturi pipe 172 provided in multiple parallel connection with the inflow pipe 179 And is mixed with the waste ammonia water, and the ammonia water of the atomized ultra fine particles is generated and injected into the denitration reactor 30. The venturi pipe 172 has a basic principle that the waste ammonia water is sucked and atomized by a negative pressure generated in accordance with an increase in the flow rate of air at the passing neck 177.

The venturi pipe 172 has a ratio of the cross-sectional area a of the portion of the pipe passage neck 177 to the cross-sectional area b of the discharge port 173 of 1: 6 to 8. When the ratio of the cross-sectional area (a) of the portion of the pipeline passage 177 to the cross-sectional area (b) of the discharge port 173 is less than 1: 6, it is difficult to atomize the waste ammonia water. The sectional area of the portion of the pipe passage neck 177 becomes small, and it is difficult to smoothly supply the waste ammonia water to the denitration reactor.

Preferably, the venturi pipe 172 has a ratio of the cross-sectional area of the portion of the pipe passage neck 177 to the cross-sectional area of the discharge port 173 of 1: 7. When the ratio of the cross sectional area of the venturi pipe 172 to the cross sectional area of the discharge port 173 is 1: 7, the waste ammonia water passes through the passage neck 177 of the pipeline, The denitration reactor (30) is atomized without the evaporator before entering.

The mixing ratio of the waste ammonia water and the air to maintain the droplet of 50 micro / liter or less is 5% or less by volume, and preferably 2% to 5% is effective for evaporation.

The air flowing into the inflow pipe 179 can have an appropriate pressure. An infusion pump may be installed in the venturi pipe 172 to form a fluid pressure, although the waste ammonia water is automatically sucked due to a pressure drop when air passes through the passage neck 177 of the venturi pipe 172.

As shown in Figs. 5 and 6, the ultrasonic atomizer 181 uses the atomization principle of the liquid by the ultrasonic vibrator. For example, if ultrasonic vibrations of 20 kHz or more are applied vertically to the water surface, the liquid absorbs the vibration energy, and ultrafine surface standing waves are generated on the surface of the liquid. . The larger the oscillation frequency, the smaller the droplet is, and when the oscillation frequency is 48 kHz, water droplets of 35 to 50 microns are generated and appear as an atomization phenomenon.

As a result of the experiment, a droplet of 40 to 50 microns is required in order to evaporate the waste ammonia water before entering the denitration reactor 30 without using an evaporator.

The atomized and diluted waste air ammonia water flows into the injection line 35 of the denitration reactor 30 and is uniformly injected into the denitration reactor 30 through the injection nozzle 37 of the injection line 35 do.

A supply adjusting means 190 is provided between the air injection equipment 110 and the inflow pipe 179. The supply regulating means 190 may selectively introduce air only into the inlet pipe 179 or mix ammonia in the ammonia storage facility 80 with air.

The supply adjusting means 190 may supply the ammonia stored in the ammonia storing facility 80 selectively to the denitration reactor 30 when it is difficult to reduce nitrogen oxides by supplying only the waste ammonia water from the denitrification reactor 30 .

For example, if the concentration of the nitrogen oxide contained in the combustion gas discharged from the denitration reactor 30 is higher than the set value by receiving the sensing information of the nitrogen oxide concentration sensor 38, The ammonia stored in the ammonia storage facility 80, rather than the waste ammonia water, is supplied to the apparatus 30 as a reducing agent.

The nitrogen oxide concentration sensor 38 is provided on the side of the combustion gas outlet 33 of the denitration reactor 30 and the nitrogen oxide concentration information detected by the nitrogen oxide concentration sensor 38 is supplied to the supply adjusting means 190, respectively.

In addition, the concentration of waste ammonia water may change depending on the occurrence of concentration. The concentration of nitrogen oxides contained in the combustion gas may also change from time to time. Therefore, it is difficult to control the concentration of nitrogen oxides discharged into the combustion gas outlet 33 of the denitration reactor 30 only by injecting waste ammonia water into the denitration reactor 30.

In this case, the supply regulating means 190 operates to regulate the concentration of nitrogen oxides discharged into the combustion gas outlet 33. The supply adjusting means 190 may adjust the supply amount of the nitrogen oxides in the case where it is difficult to reduce nitrogen oxides only by the amount of waste ammonia based on the concentration of nitrogen oxides detected by the nitrogen oxide concentration sensor 38 and the concentration of the detected ammonia water The ammonia stored in the ammonia storage facility 80 is automatically supplied to the reducing agent of the denitration reactor 30.

The waste ammonia water treatment system includes a denitration reactor 30 for removing nitrogen oxide contained in the combustion gas by contacting with ammonia and an ammonia removing unit 30 for removing ammonia from the ammonia storage facility 80, An ammonia dissolving tank 150 for converting the ammonia water into ammonia water and storing the converted ammonia water into ammonia water, and an atomizing unit 170 for atomizing the waste ammonia water, and a denitrification unit 170 for supplying air to the atomized waste ammonia water so that the volume ratio of ammonia to air becomes 5% And an air injection device 110 for injecting the air into the reaction device 30.

The atomization means 170 is a Venturi atomizer 171 or an ultrasonic atomizer 181.

The Venturi sprayer 171 includes a venturi tube 172 and an inlet tube 179. The venturi pipe 172 is in the form of a pipe and has an outlet 173 connected to the injection line 35 provided in the denitration reactor 30 and an inlet 175 communicating with the inlet pipe 179, A portion of the passage neck 177 in which the cross-sectional area of a part of the pipe is reduced is formed. The exhaust port of the venturi pipe 172 is connected to the injection line 35 of the denitration reactor 30 but the outlet 173 of the venturi pipe 172 is connected to the injection nozzle 35 of the denitrification reactor 30. [ (Not shown).

The venturi pipe 172 is installed in a multiple parallel structure and the inlet of the venturi pipe 172 is communicated with the inlet pipe 179 so that the air and the waste ammonia water are introduced into the inlet of the venturi pipe 172 through the inlet pipe 179 . The inlet pipe 179 is connected to the air injection equipment 110 and the ammonia water injection tank 160.

The ratio of the cross-sectional area (a) of the passage neck 177 of the venturi pipe 172 to the cross-sectional area (b) of the discharge port 173 is 1: 6 to 8, preferably 1: 7.

The ultrasonic atomizer 181 is preferably an ultrasonic atomizer using an ultrasonic vibrator.

 The ammonia dissolution tank 150 is provided with a waste ammonia water concentration sensor 151 for detecting the concentration of the waste ammonia water and a nitrogen oxide concentration sensor 38 for detecting the concentration of nitrogen oxides in the combustion gas discharge port 33, .

The air injection equipment 110 is connected to the inflow pipe 179 to supply air to the inflow pipe 179. The air injection unit 110 may be connected to a separate pipe connecting the venturi pipe 172 and the injection line 35 of the denitrification device 30 to supply air for dilution to the atomized waste ammonia water.

The supply amount of ammonia stored in the waste ammonia storage facility 80 is selectively supplied to the denitration reactor 30 by receiving the detection information of the waste ammonia water concentration sensor 151 and the nitrogen oxide concentration sensor 38, Means 190 are provided.

The ammonia injection system of the denitration reactor includes an denitration reactor 30 for removing nitrogen oxide contained in the combustion gas by contacting with ammonia, an ammonia storage facility 80 for storing ammonia for injection into the denitrification reactor, An ammonia dissolving tank 150 for converting the waste ammonia generated in the denitration reactor 30 and the ammonia discharged from the ammonia storage facility 80 into waste ammonia water and storing the ammonia water therein and an ammonia or ammonia dissolution tank And feed adjusting means 190 for controlling the selective introduction of the waste ammonia water stored in the tank 150 into the denitration reactor 30.

And atomizing means (170) for atomizing the waste ammonia water before injecting it into the denitration reactor (30). The atomization means 170 is a Venturi atomizer 171 or an ultrasonic atomizer 181. And an air injection system for supplying air to the atomized waste ammonia water to mix the waste ammonia water with respect to the air to maintain the volume ratio of 5% or less.

A nitrogen oxide concentration sensor 38 for measuring the concentration of nitrogen oxide discharged through the combustion gas outlet 33 is provided at the combustion gas outlet 33 of the denitration reactor 30. The ammonia dissolution tank 150 is provided with a waste ammonia water concentration sensor 151 for sensing the concentration of the waste ammonia water.

The supply adjusting means 190 adjusts the supply amount of ammonia stored in the ammonia storage facility 80 or the ammonia storage tank 150 stored in the ammonia dissolving tank 150 based on the measurement results of the nitrogen oxide concentration sensor 38 and the waste ammonia water concentration sensor 151 Is selectively injected into the denitration reactor (30).

The supply adjusting means 190 injects only the waste ammonia water into the denitration reactor 30 based on the measurement results of the nitrogen oxide concentration sensor 38 and the waste ammonia water concentration sensor 151 to determine that it is difficult to reduce the nitrogen oxides , And ammonia stored in the ammonia storage facility (80) is automatically supplied to the reducing agent of the denitration reactor (30).

The ammonia injection system of the denitration reactor can recycle waste ammonia generated from the denitrification reactor 30 and the ammonia storage facility as a reducing agent of the denitrification reactor 30. When it is difficult to reduce nitrogen oxides only by waste ammonia, And is configured to perform denitrification reaction by receiving ammonia from the storage facility.

Hereinafter, a process of converting waste ammonia into waste ammonia water and collecting the waste ammonia as a reducing agent in the denitrification reactor will be described.

The waste ammonia generated from the denitrification reactor 30 and the ammonia storage facility 80 is collected in the waste ammonia collection means 130 and the outflow ammonia collection means 140 and then stored in the ammonia dissolution tank. In the ammonia dissolving tank, waste ammonia is absorbed with water and stored as final ammonia water of 25% or less concentration.

The waste ammonia water stored in the ammonia dissolving tank 150 is transferred to the ammonia water injection tank 160 by the transfer pump 155 and then atomized by the Venturi sprayer 171 or the ultrasonic atomizer 181, Is mixed with the air to maintain the volume ratio of 5% or less, and then injected into the denitration reactor 30.

The atomization of the waste ammonia water through the Venturi sprayer 171 proceeds in the following manner.

The waste ammonia water supplied from the transfer pump 155 is stored in a predetermined amount in the ammonia water injection tank 161 and then injected into the passage neck 177 of the venturi pipe 172. At this time, And generates atomized waste ammonia water (Wam + Aim) of the ultrafine particles while passing through a plurality of venturi tubes 172 installed in parallel. Wasted ammonia water (Wam + Aim), which is atomized and mixed with air, is injected into the injection line 35 of the denitration reactor 30 and uniformly injected into the denitration reactor 30 through the injection nozzle 37.

On the other hand, atomization of waste ammonia water through an ultrasonic atomizer proceeds in the following manner.

The waste ammonia water supplied from the transfer pump 155 is stored in a predetermined amount in the ammonia water injection tank 160 and then supplied to the ultrasonic atomizer 181. The waste ammonia water Wam supplied to the ultrasonic atomizer 181 is atomized by the vibration of the ultrasonic vibrator 183 and is supplied to the atomized waste water Aim due to the air stream generated by the air supplied from the air injection equipment 110. [ Ammonia water (Wam + Aim). Wasted ammonia water (Wam + Aim), which is atomized and mixed with air, is injected into the injection line 35 of the denitration reactor 30 and is uniformly injected into the denitration reactor through the injection nozzle 37.

In the process of injecting the waste ammonia water into the denitration reactor, the supply adjusting means is provided with the concentration information sensed by the nitrogen oxide concentration sensor 38 and the waste ammonia water concentration sensor 151 to reduce the amount of nitrogen oxides The ammonia stored in the ammonia storage facility 80 is automatically controlled to be supplied to the reducing agent of the denitration reactor 30.

The ammonia stored in the ammonia storage facility 80 generates gaseous ammonia of a certain pressure through the evaporator 90 and the regulator 100 and is mixed and diluted with the air of the air injection equipment 110 in the mixer 120, And is injected into the inside of the reaction apparatus 30.

When the gaseous ammonia is injected into the denitration reactor 30, the volume ratio of ammonia to air is adjusted to 5% or less to prevent ammonia from exploding.

The scope of the invention is defined by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein. It is self-evident that we can make changes.

10: Combustion device 20:
30: Denitration reactor 31: Combustion gas inlet
33: combustion gas outlet 35: injection line
37: injection nozzle 38: nitrogen oxide concentration sensor
39: outlet pipe 40: air preheater
50: Electrostatic precipitator 60: Wet desulfurization equipment
70: Chimney 80: Ammonia storage facility
90: Evaporator 100: Regulator
110: air injection equipment 120: mixer
130: waste ammonia collecting means 140: effluent ammonia collecting means
150: ammonia dissolution tank 151: waste ammonia water concentration sensor
153: supply pipe 155: transfer pump
160: ammonia water injection tank 170: atomization means
171: Venturi Sprayer 172: Venturi Liner
173: outlet 175: inlet
177: passing neck 179: inlet tube
181: Ultrasonic atomizer 183: Ultrasonic oscillator
190: Supply adjustment means

Claims (13)

delete delete delete delete delete delete delete delete delete delete A denitration reaction device for removing nitrogen oxide contained in the combustion gas by contacting with ammonia,
An ammonia storage facility for storing ammonia to be injected into the denitrification reactor;
An ammonia dissolution tank for converting waste ammonia generated in the denitrification apparatus and ammonia discharged from the ammonia storage facility into waste ammonia water and storing the waste ammonia water,
And a supply regulating means for selectively controlling the ammonia stored in the ammonia storage facility or the waste ammonia water stored in the ammonia dissolving tank to be injected into the denitrification reactor. The method of claim 11,
Atomizing means for atomizing the waste ammonia water before injecting the waste ammonia water into the denitration reactor,
And an air injection system for supplying and mixing air to the atomized waste ammonia water. The method of claim 11,
A nitrogen oxide concentration sensor disposed on the combustion gas outlet side of the denitration reactor for measuring the concentration of nitrogen oxide discharged through the combustion gas outlet;
And a waste ammonia water concentration sensor provided in the ammonia dissolution tank for sensing the concentration of the waste ammonia water,
The supply control means controls the supply of ammonia stored in the ammonia storage facility or the waste ammonia water stored in the ammonia dissolution tank to be selectively injected into the denitrification reaction device in accordance with the measurement results of the nitrogen oxide concentration sensor and the waste ammonia water concentration sensor The ammonia injection system comprising:

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