CN108499343A - A kind of coal-fired boiler tail gas integrated desulfurization, denitration, smoke harnessing system - Google Patents

Abstract

The invention discloses an integrated desulfurization, denitrification, and dust removal treatment system for coal-fired boiler tail gas; the technical problem to be solved is that traditional coal-fired boiler tail gas treatment is basically an independent unit, and this tail gas treatment system has large investment, many equipment, and occupies Large area, complex operation, high operating cost, and technical problems that heating companies cannot bear. The technical solutions and systems adopted include the ozone oxidation system, absorbent preparation system, absorption and washing integrated system and dehydration system, the ozone oxidation system and absorbent preparation system are connected to the absorption and washing integration system, the absorption and washing integration system and the dehydration system connected. Advantages: This system adopts the "power wave scrubber simultaneous desulfurization, dust removal and denitrification process" instead of bag dust removal, sprays urea solution or denitrification in the furnace, and sprays desulfurization in the empty tower, realizing integrated desulfurization, denitrification and dust removal, with a large footprint Small size, simple operation, low operating cost, high desulfurization, denitrification and dust removal efficiency.

Description

An integrated desulfurization, denitrification and dust removal treatment system for coal-fired boiler tail gas

technical field

The invention relates to an integrated desulfurization, denitrification and dust removal treatment system for tail gas of a coal-fired boiler.

Background technique

The construction of 2×29MW hot water boilers in a central heating project in a county in Northwest China was completed in 2012. The construction of the project has changed the messy layout of the original boiler room, scattered and independent heating of various departments, small power of a single boiler, low thermal efficiency, and low heat supply. A series of heating legacy problems such as poor effect. At the same time, it improves the urban infrastructure, effectively saves resources, reduces urban pollution, improves people's living environment, and facilitates residents' daily life. The heating area reaches 1 million square meters, and its economic, environmental and social benefits are very significant. .

At the beginning of the construction of the heat source plant, the flue gas treatment equipment was an ordinary granite water bath dust collector, with a dust removal efficiency of about 70%, a low desulfurization efficiency, and no denitrification device. After testing, the exhaust gas SO2≦1200mg/Nm3, NOx≦380mg/Nm3, dust≦900mg/Nm3. This directly leads to a large amount of SO2, NOx and dust being discharged into the atmosphere without treatment, which is incompatible with the relevant national environmental protection policies and urban development directions, especially the new "Boiler Air Pollutant Emission Standards" in 2014 (GB13271-2014) After the implementation, the current flue gas tail treatment cannot meet the requirements of the new environmental protection standard.

Traditional coal-fired boiler tail gas treatment is basically an independent unit, dust removal uses a bag filter, desulfurization uses empty tower spraying lye, and denitrification uses SNCR or SCR. This kind of tail gas treatment system has large investment, many equipments, large floor area, complicated operation and high operating cost, which is difficult for heating enterprises to bear.

Contents of the invention

The technical problem to be solved by the present invention is: traditional coal-fired boiler tail gas treatment is basically an independent unit. This kind of tail gas treatment system has large investment, many equipments, large floor area, complicated operation and high operation cost, and the heat supply enterprise is very expensive. Unbearable technical problems.

The design idea of the present invention is that the process utilizes the "power wave scrubber simultaneous desulfurization, dust removal and denitrification process" to treat the tail gas containing dust, sulfur dioxide and nitrogen oxides produced by coal-fired boilers to meet the emission standards; Installed before the outlet of the boiler induced draft fan and the inlet of the power wave scrubber, it has no effect on the boiler body, has high denitrification efficiency, and is safe and reliable.

The purpose of the present invention is to provide an integrated desulfurization, denitrification and dust removal treatment system for coal-fired boiler tail gas. Low operating cost, high desulfurization, denitrification and dust removal efficiency.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

An integrated desulfurization, denitrification, and dust removal treatment system for coal-fired boiler tail gas, including an ozone oxidation system, an absorbent preparation system, an integrated absorption and washing system, and a dehydration system. Both the ozone oxidation system and the absorbent preparation system are connected to the integrated absorption and washing system , the absorption and washing integrated system is connected with the dehydration system,

The ozone oxidation system includes a liquid oxygen station, an ozone generator and an ozone dosing device. The output of the liquid oxygen station is connected to the input of the ozone generator through a pipeline, and the output of the ozone generator is connected to the first input of the ozone dosing device through a pipeline. The tail gas of the coal-fired boiler is connected to the second input of the ozone dosing device through the pipeline, and the output of the ozone dosing device is connected to the first input of the integrated absorption and washing system through the pipeline;

The absorbent preparation system includes a batching box, the batching box is filled with absorbent, and the output of the batching box is connected to the second input of the integrated absorption and washing system through pipelines;

The absorption and washing integrated system includes power wave scrubber, power wave circulation pump, gas-liquid separation tower, absorption circulation pump, sprayer, cyclone demister and wet electrostatic precipitator,

The ozone dosing device is installed at the position 12 meters from the exit flue of the induced draft fan of the boiler system to the power wave scrubber. The power wave scrubber is connected to the gas-liquid separation tower through the expansion joint, and the output of the batching box is connected to the gas-liquid separation tower through the pipeline. The first input of the ozone dosing device, the output of the ozone dosing device is connected to the first input of the power wave scrubber through the pipeline, the sprayer is set in the gas-liquid separation tower, the cyclone demister is set in the gas-liquid separation tower and is located in the spray Above the shower, the wet electrostatic precipitator is arranged on the top of the gas-liquid separation tower, and a chimney is set on the top of the wet electrostatic precipitator. The first output of the gas-liquid separation tower is connected to the second power wave scrubber through the power wave circulation pump and pipelines. Two inputs; the second output of the gas-liquid separation tower is connected to the input of the sprayer through the absorption circulation pump and pipeline; the third output of the gas-liquid separation tower is connected to the dehydration system; the bottom of the gas-liquid separation tower is connected to the oxidation through the pipeline Air;

The dehydration system includes a gypsum discharge pump, a hydrocyclone and a belt filter. The third output of the gas-liquid separation tower is connected to the input of the hydrocyclone through the gypsum discharge pump and pipelines, and the first output of the hydrocyclone is connected to the second output of the hydrocyclone. The second output is connected to the second input of the gas-liquid separation tower through the pipeline, the third output and the fourth output of the hydrocyclone are connected to the input of the belt filter through the pipeline, and the product outlet of the belt filter outputs the product, the belt filter The sewage outlet of the filter is connected to the pit through the pipeline, and the output of the pit is connected to the second input of the gas-liquid separation tower and the sewage treatment station in two ways through the vertical pump and the pipeline.

The coal-fired boiler tail gas integrated desulfurization, denitrification, and dust removal treatment system of the present invention, the tail gas treatment system uses "dynamic wave efficient washing desulfurization, denitrification, and dust removal method" to fully consider the existing small site, and the coal-fired boiler is dedusted by stone impact water bath Finally, the flue gas has the characteristics of large moisture content, high dust content, high SO2 content, and short reaction time of NOX after ozone oxidation. Innovation and improvement are carried out under the premise of safety and reliability.

The coal-fired boiler tail gas integrated desulfurization, denitrification, and dust removal treatment system of the present invention includes an ozone oxidation system, an absorbent preparation system, an integrated absorption and washing system, and a dehydration system. The ozone dosing device in the ozone oxidation system is installed at a position 12 meters from the outlet flue of the induced draft fan to the power wave scrubber, so that there is sufficient time to oxidize NOX into N2O5 and be absorbed in the absorption system. The flue gas purified by the absorption and washing integrated system is discharged up to the standard from the chimney at the top of the tower. The dehydration system is connected to the gas-liquid separation tower through the gypsum discharge pump, and the washed dust, gypsum, and nitrate are dehydrated and discharged together with the slag.

In the coal-fired boiler tail gas integrated desulfurization, denitrification, and dust removal treatment system of the present invention, the liquid outlet at the bottom of the power wave scrubber in the absorption and washing integrated system is connected to the gas-liquid separation tower through a power wave circulation pump. The liquid outlet at the bottom of the gas-liquid separation tower is connected to the high-efficiency spray layer through the absorption circulation pump. The wet electrostatic precipitator is arranged on the top of the gas-liquid separation tower, the flushing water comes from the process water main pipe, and the washing liquid flows directly to the bottom tank of the gas-liquid separation tower for recycling. Coal-fired boiler tail gas is affected by factors such as coal quality, dust, SO2, and NOX have fluctuations and irregularities. This system has a high applicability to this. The wet electrostatic precipitator can effectively control PM2.5 particles (PM0 .5, PM10), SO3 acid mist, gypsum rain, aerosol, heavy metal mercury, dioxin, etc., reduce chimney tail feathers, completely solve the problem of gypsum rain and large white smoke, dust and other standards and ultra-clean ultra-low emissions.

Preferably, the absorbent is formed by mixing process water and sodium hydroxide.

Preferably, stirring shafts are arranged in the batching box, the lower part of the gas-liquid separation tower and the pit, and the stirring shafts are all driven by motors.

Preferably, water or trench slurry is injected into the pit.

Preferably, a safety valve is provided on the air intake pipe of the ozone generator. The safety valve is set to open when the system pressure exceeds the design value to ensure the safety of the system; the qualified gas source enters the ozone generating chamber after decompression and stabilization. The ozone generator mentioned here is a conventional technical product applied in this technical field in the prior art, and is directly purchased and obtained.

The "liquid oxygen station, ozone generator and ozone dosing device" mentioned in the technical solution of the present invention are all conventional technical products in this technical field in the prior art, and can be purchased directly.

The "power wave scrubber, power wave circulation pump, gas-liquid separation tower, absorption circulation pump, sprayer, swirl flow demister and wet electrostatic precipitator" mentioned in the technical solution of the present invention are all original in the prior art. Conventional technical products in the technical field can be purchased directly.

"Gypsum discharge pump, hydrocyclone and belt type filter" mentioned in the technical solution of the present invention are all conventional technical products in the technical field in the prior art, directly purchased and obtained.

The present invention compares with prior art, and its beneficial effect is:

1. This system adopts "power wave scrubber simultaneous desulfurization, dust removal and denitrification process" instead of bag dust removal, sprays urea solution (SNCR) or (SCR) denitrification in the furnace, and sprays desulfurization in the empty tower. Realized the integration of desulfurization, denitrification and dust removal. It has the advantages of small footprint, simple operation, low operating cost, and high desulfurization, denitrification, and dust removal efficiency.

2. In this system, desulfurization, denitrification, and dust removal are simultaneously completed in one device of the power wave scrubber, and the clean flue gas passing through the gas-liquid separation tower is discharged up to the standard in the chimney at the top of the tower. Desulfurization efficiency ≥ 98%, denitrification efficiency ≥ 87%, dust removal efficiency ≥ 99%. Dust, SO2, and NOx are washed in the absorbing liquid after being absorbed, oxidized, and precipitated, and then dehydrated and discharged by the belt filter. The filtrate is sent to the pit for recycling. The system occupies a small area, has high desulfurization, denitrification and dust removal efficiency, low operating cost and simple operation.

3. In this system, the ozone dosing device is installed on the flue 12 meters before the power wave scrubber, and quickly N2O5, which is insoluble in water, is absorbed by the alkaline absorption liquid in the power wave scrubber, and the NOx emission after denitrification is ≦50mg /Nm3.

4. In this system, the bottom of the gas-liquid separation tower is used as a circulation pool to form a closed-circuit circulation system through a power wave circulation pump and a power wave scrubber.

5. In this system, the gas-liquid separation tower is also installed as a desulfurization tower with a spray layer for deep desulfurization. After desulfurization, the SO2 emission is ≦35mg/Nm3.

6. In this system, the wet electrostatic precipitator is installed on the top of the gas-liquid separation tower, which can effectively control PM2.5 particulate matter (PM0.5, PM10), SO3 acid mist, gypsum rain, aerosol, heavy metal mercury, and dioxin Ying et al. reduced the tail feathers of the chimney, completely solved the problems of gypsum rain and large white smoke, and achieved ultra-clean and ultra-low emissions of dust. Chimney outlet dust ≦ 10mg/Nm3.

7. In this system, the washing water of the wet electrostatic precipitator comes from the process water pipe, and at the same time, the washing liquid of the cyclone demister is washed and flows to the bottom of the gas-liquid separation tower to be mixed in the circulating slurry.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work, wherein:

Fig. 1 is the block diagram of the process flow system of this embodiment.

Detailed ways

The technical solutions of the present invention will be described in detail below, but the protection scope of the present invention is not limited to the embodiments.

In order to more clearly illustrate the technical solution in the embodiment of the present invention, further description will be made below in conjunction with the accompanying drawing 1 and specific implementation methods.

The following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example:

The coal-fired boiler tail gas integrated desulfurization, denitrification, and dust removal treatment system in this embodiment includes an ozone oxidation system, an absorbent preparation system, an integrated absorption and washing system, and a dehydration system. Both the ozone oxidation system and the absorbent preparation system are connected to the absorption and washing system. Integrated system, the integrated absorption and washing system is connected with the dehydration system.

The ozone oxidation system includes a liquid oxygen station 1, an ozone generator 2 and an ozone dosing device 3. The output of the liquid oxygen station 1 is connected to the input of the ozone generator 2 through a pipeline, and the output of the ozone generator 2 is connected to the ozone dosing device through a pipeline. The first input of the device 3, the tail gas of the coal-fired boiler is connected to the second input of the ozone dosing device 3 through the pipeline, and the output of the ozone dosing device 3 is connected to the first input of the integrated absorption and washing system through the pipeline.

A safety valve is set on the air intake pipeline of the ozone generator 2. The safety valve is set to open when the system pressure exceeds the design value to ensure the safety of the system; the qualified gas source enters the ozone generating chamber after decompression and stabilization. The ozone generator mentioned here is a conventional technical product applied in this technical field in the prior art, and is directly purchased and obtained.

During implementation, part of the oxygen in the ozone generating chamber becomes ozone through medium-frequency high-voltage discharge, and the product gas is output from the ozone outlet after temperature, pressure, and flow monitoring and adjustment. The ozone generation chamber is equipped with an ozone gas intake port, and the ozone output concentration can be monitored online through the ozone concentration detector equipped with each ozone generator, and the ozone output can be calculated. The ozone concentration detector mentioned here is a conventional technical product applied in this technical field in the prior art, and is directly purchased and obtained.

Further, the cooling water of the ozone generator is designed as a closed-circuit cooling water system, which exchanges heat through a plate heat exchanger to provide cooling water for the ozone generator. The closed-circuit circulating water cooling system includes a plate heat exchanger, a circulating water pump, an expansion tank and valves. The cooling water outlet pipeline of the ozone generator is equipped with a flow switch and a temperature transmitter, which will alarm when the cooling water flow is insufficient and the temperature exceeds the set value.

Furthermore, an ozone/oxygen leakage alarm device is installed in the ozone workshop. When the ozone/oxygen leakage in the environment in the workshop exceeds the standard, the system determines to output an alarm, start the exhaust fan or shut down according to the detection signal.

The ozone dosing device 3 is installed at a position 12 meters in front of the power wave scrubber 4. The denitrification method of the ozone oxidation method mainly utilizes the strong oxidizing property of ozone to oxidize insoluble low-valence nitrogen oxides into soluble high-valence nitrogen oxides. matter, and then absorb the nitrogen oxides in the dynamic wave scrubber 4 to achieve the purpose of removal. Under different concentrations and ratios of pollutants such as NOx, the denitrification system can simultaneously remove pollutants such as NOx, sulfur dioxide, and particulate matter in the flue gas with high efficiency, and has no impact on the boiler body. The traditional SNCR denitrification process is in the furnace. Spraying urea solution or ammonia water will corrode the water wall, economizer and air preheater. Ozone oxidation denitrification is the best denitrification technology in chain hot water boilers.

According to the complex oxidation reaction process of O3 for NOx, in fact, it is finally reflected by the change of the valence state of N. The main reaction process is as follows:

2NO+3O3＝N2O5+3O2

2N02+O3＝N2O5+O2

NO+O3＝N O2+O2

Compared with other chemical substances in the gas phase such as CO, SOx, etc., NOx can be quickly oxidized by ozone, which makes the ozonation of NOx highly selective. Because NOx in the gas phase is converted into ionic compounds dissolved in aqueous solution, this makes the oxidation reaction more complete, thereby irreversibly removing NOx without secondary pollution. After the oxidation reaction, the added ozone is consumed by the reaction, and the excess ozone can be decomposed in the gas-liquid separation tower. In addition to NOx, some heavy metals such as mercury and other heavy metal pollutants are also oxidized by ozone. The high concentration of dust or solid particles in the flue gas will not affect the removal efficiency of NOx.

The absorbent preparation system includes a batching box 12, which contains absorbent, and the output of the batching box 12 is connected to the second input of the integrated absorption and washing system through pipelines. The absorbent is formed by mixing process water and sodium hydroxide. Stirring shafts are set in the batching box 12, and the stirring shafts are all driven by motors.

The absorption and washing integrated system includes power wave scrubber 4, power wave circulation pump 5, gas-liquid separation tower 6, absorption circulation pump 7, sprayer 8, cyclone demister 9 and wet electrostatic precipitator 10, ozone dosing The device 3 is installed at the position 12 meters from the exit flue of the induced draft fan of the boiler system to the power wave scrubber 4. The power wave scrubber 4 is connected to the gas-liquid separation tower 6 through an expansion joint, and the output of the batching box 12 is connected to the gas-liquid through a pipeline. The first input of the separation tower 6, the output of the ozone dosing device 3 is connected to the first input of the power wave scrubber 4 through a pipeline, the shower 8 is arranged in the gas-liquid separation tower 6, and the cyclone demister 9 is arranged on In the gas-liquid separation tower 6 and above the sprayer 8, the wet electrostatic precipitator 10 is arranged at the top of the gas-liquid separation tower 6, and a chimney 11 is arranged on the top of the wet electrostatic precipitator 10, and the first output of the gas-liquid separation tower 6 Connect the second input of power wave scrubber 4 by power wave circulation pump 5 and pipeline; The second output of gas-liquid separation tower 6 is connected the input of sprayer 8 by absorption circulation pump 7 and pipeline; The third output of the dehydration system is connected; the oxidation air is connected to the bottom of the gas-liquid separation tower 6 through a pipeline. A stirring shaft is arranged at the bottom of the gas-liquid separation tower 6, and the stirring shafts are all driven by a motor.

The boiler tail gas oxidized by ozone enters the power wave scrubber 4, and the power wave scrubber 4 is connected with the gas-liquid separation tower 6 through the power wave circulation pump 5, and the bottom of the gas-liquid separation tower 6 is used as a circulation pool to carry calcium hydroxide mixed circulation fluid, according to The pH value of the circulating liquid in the tank at the bottom of the tower controls the amount of calcium hydroxide solution added, and the power wave circulation pump 5 pressurizes the calcium hydroxide solution into the power wave scrubber 4 . In the dynamic wave scrubber 4, the calcium hydroxide mixed circulating fluid with an alkalinity of PH=11-13 passes through the involute swirling kinetic energy nozzle to spray and wash the flue gas, and quickly reduce the temperature of the flue gas from above 130°C to 60°C At the same time, most of the soot in the flue gas is captured into the circulating liquid; most of the sulfur dioxide and other acid gases in the flue gas combine with the active OH- in the circulating liquid to form an intermediate, and the SO32- in the intermediate, Then combine with Ca2+ to form CaSO3 precipitation; at the same time, the low-valence nitrogen oxides oxidized by ozone are oxidized to high-valence nitrogen oxides, which are absorbed by calcium hydroxide solution in the dynamic wave scrubber 4 to achieve the purpose of removal. After washing, the clean gas enters the gas-liquid separation tower 6, and the sprayer 8 on the upper part of the gas-liquid separation tower 6 is further desulfurized through the absorption circulation pump 7 and passed through the swirl demister 9 assembly. , the water mist and part of the residual smoke in the flue gas are further reduced; the gas continues to pass through the wet electrostatic precipitator 10, and the wet electrostatic precipitator 10 can effectively control PM2.5 particulate matter (PM0.5, PM10), SO3 acid mist , gypsum rain, aerosols, heavy metal mercury, dioxin, etc., reduce chimney tail feathers, completely solve the problems of gypsum rain and large white smoke, dust and other standards and ultra-clean ultra-low emissions. The gas SO2≤35mg/Nm3, NOx≤50mg/Nm3, and dust≤10mg/Nm3 of the above deeply purified gas are sent into the chimney 11 and then discharged.

Desulfurization chemical reaction process

Absorption: SO2(g)→SO2(l)+H2O→H++HSO3-→H++SO32-

Dissolution: Ca(OH)2(s)→Ca2++2OH-

CaSO3(s)→Ca2++SO32-

Neutralization: OH-+H+→H2O

OH-+HSO3-→SO32-+H2O

Oxidation: HSO3-+1/2O2→SO32-+H+

SO32-+1/2O2→SO42-

Crystallization: Ca2++SO32-+1/2H2O→CaSO3·1/2H2O(s)

Ca2++SO42-+2H2O→CaSO4·2H2O(s)

The dehydration system comprises a gypsum discharge pump 13, a hydrocyclone 14 and a belt filter 15, and the third output of the gas-liquid separation tower 6 is connected to the input of the hydrocyclone 14 through the gypsum discharge pump 13 and a pipeline, and the hydrocyclone The first output and the second output of 14 are connected to the second input of the gas-liquid separation tower 6 by the pipeline, and the third output and the fourth output of the hydrocyclone 14 are connected to the input of the belt filter 15 by the pipeline. The product outlet of the filter 15 outputs the product, the sewage outlet of the belt filter 15 is connected to the pit 16 through a pipeline, and the output of the pit 16 is connected to the gas-liquid separation tower 6 in two ways through a vertical pump and a pipeline. Second input and sewage treatment station. Inject water or slurry from the trench into the pit 16, and set stirring shafts in the pit 16, and the stirring shafts are all driven by motors.

The circulating liquid that has absorbed dust, nitrogen oxides, and sulfur dioxide flows into the bottom of the gas-liquid separation tower 6 for recycling, and the mother liquor produced is sent to the dehydration system by the gypsum discharge pump 13, and the gypsum and dust pass through the hydrocyclone 14 and the belt filter. 15 is dehydrated and exported together with the slag, and the detached water is returned to the pit 16 for recycling, and the waste water in the pit 16 is regularly sent to the sewage treatment station in the factory area for treatment and discharged after reaching the standard. The waste liquid recovered by the pit 16 is regularly discharged to the existing sewage treatment station through the pit pump.

During the implementation of this embodiment, in order to prevent the power wave scrubber 4 from breaking the liquid and causing equipment damage, a shower for spraying in case of emergency is provided in the power wave scrubber 4, and the input of the shower is through the pipeline and the setting. A regulating valve for emergency water supply in the pipeline is connected to an external water supply. The implementation of this sprinkler is interlocked controlled by the regulating valve of the emergency water supply and the temperature sensor arranged at the outlet of the power wave scrubber 4 for detecting the gas temperature.

The working process in the present embodiment,

Boiler exhaust gas containing dust, nitrogen oxides, and sulfur dioxide is sent to the exhaust gas treatment system through the induced draft fan, and the liquid oxygen purchased at the liquid oxygen station 1 is filled into the liquid oxygen tank, and the liquid oxygen passes through the vaporizer, the pressure reducing valve group, After entering the dust filter, decompressing and stabilizing the pressure, it enters the ozone generator 2. A safety valve is designed on the intake pipe of the ozone generator 2. When the system pressure exceeds the design value, it opens to ensure the safety of the system. Qualified gas source enters the ozone generating chamber after decompression and stabilization. Part of the oxygen in the ozone generation room is converted into ozone through intermediate frequency high-voltage discharge, and the ozone enters the ozone dosing device 3 and the boiler exhaust gas undergoes oxidation reaction in the flue. Nitrogen oxides are oxidized to soluble high-valence nitrogen oxides, and then the nitrogen oxides are absorbed in the dynamic wave scrubber 4 to achieve the purpose of removal. The boiler tail gas oxidized by ozone enters the power wave scrubber 4, and the power wave scrubber 4 is connected with the gas-liquid separation tower 6 through the power wave circulation pump 5, and the bottom of the gas-liquid separation tower 6 is used as a circulation pool to carry calcium hydroxide mixed circulation fluid, according to The pH value of the circulating liquid in the tank at the bottom of the tower controls the amount of calcium hydroxide solution added. The power wave circulation pump pressurizes the 5 calcium hydroxide solution into the power wave scrubber 4. In the dynamic wave scrubber 4, the calcium hydroxide mixed circulating fluid with an alkalinity of PH=11-13 passes through the involute swirling kinetic energy nozzle to spray and wash the flue gas, and quickly reduce the temperature of the flue gas from above 130°C to 60°C At the same time, most of the dust in the flue gas is trapped into the circulating fluid. Most of the sulfur dioxide and other acid gases in the flue gas combine with the active OH- in the circulating liquid to form intermediates, and the SO32- in the intermediates combines with Ca2+ to form CaSO3 precipitates. At the same time, the low-valence nitrogen oxides oxidized by ozone are oxidized to high-valence nitrogen oxides, which are absorbed by the calcium hydroxide solution in the dynamic wave scrubber 4 to achieve the purpose of removal. After washing, the clean gas enters the gas-liquid separation tower 6, and the sprayer 8 on the upper part of the gas-liquid separation tower 6 is further desulfurized through the absorption circulation pump 7 and passed through the cyclone demister 9 assembly. In the cyclone demister 9, the water mist and part of the residual smoke in the flue gas are further reduced. The gas continues to pass through the wet electrostatic precipitator 10, which can effectively control PM2.5 particulate matter (PM0.5, PM10), SO3 acid mist, gypsum rain, aerosol, heavy metal mercury, dioxin, etc. Reduce the tail feathers of the chimney, completely solve the problems of gypsum rain and large white smoke, and achieve ultra-clean and ultra-low emissions of dust. The absorption and washing integrated desulfurization, denitrification and dust removal system has desulfurization efficiency ≥ 98%, denitrification efficiency ≥ 87%, and dust removal efficiency ≥ 99%. The gas SO2≤35mg/Nm3, NOx≤50mg/Nm3, and dust≤10mg/Nm3 of the above deeply purified gas are sent into the chimney 11 and then discharged.

The coal-fired boiler tail gas integrated desulfurization, denitrification, and dust removal treatment system of this embodiment includes an ozone oxidation system for coal-fired boiler tail gas, an absorbent preparation system, an absorption and washing integrated desulfurization, denitrification, and dust removal system, and a dehydration system. The desulfurization efficiency ≥98%, denitrification efficiency ≥87%, dust removal efficiency ≥99%; gypsum dust dehydration system. This system uses "power wave scrubber simultaneous desulfurization, dust removal and denitrification process" instead of bag dust removal, sprays urea solution (SNCR) or (SCR) denitrification in the furnace, and sprays desulfurization in the empty tower, realizing integrated desulfurization, denitrification and dust removal; The system has a small footprint, simple operation, low operating costs, and high desulfurization, denitrification, and dust removal efficiencies. The implementation purpose of this system is to control the pollution to the environment and build a clean production device by adopting feasible treatment methods, while occupying a small area, low operating costs, energy saving and environmental protection.

As stated above, while the invention has been shown and described with reference to certain preferred embodiments, this should not be construed as limiting the invention itself. Various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (5)

1. A coal-fired boiler tail gas integrated desulfurization, denitrification, and dust removal treatment system is characterized in that: it includes an ozone oxidation system, an absorbent preparation system, an absorption and washing integrated system and a dehydration system, and the ozone oxidation system and the absorbent preparation system are both Connect the absorption and washing integrated system, the absorption and washing integrated system is connected with the dehydration system, The ozone oxidation system includes a liquid oxygen station (1), an ozone generator (2) and an ozone dosing device (3). The output of the liquid oxygen station (1) is connected to the input of the ozone generator (2) through a pipeline, and the ozone generator The output of (2) is connected to the first input of the ozone dosing device (3) through the pipeline, and the exhaust gas of the coal-fired boiler is connected to the second input of the ozone dosing device (3) through the pipeline, and the output of the ozone dosing device (3) The first input of the integrated absorption and washing system is connected through a pipeline; The absorbent preparation system includes a batching box (12), the batching box (12) is filled with absorbent, and the output of the batching box (12) is connected to the second input of the integrated absorption and washing system through a pipeline; The absorption and washing integrated system includes a power wave scrubber (4), a power wave circulation pump (5), a gas-liquid separation tower (6), an absorption circulation pump (7), a sprayer (8), a cyclone demister ( 9) and wet electrostatic precipitator (10), The ozone dosing device (3) is installed at the position 12 meters from the outlet flue of the induced draft fan of the boiler system to the power wave scrubber (4), and the power wave scrubber (4) is connected to the gas-liquid separation tower (6) through an expansion joint, The output of the batching box (12) is connected to the first input of the gas-liquid separation tower (6) through the pipeline, and the output of the ozone dosing device (3) is connected to the first input of the power wave scrubber (4) through the pipeline, and the spray The device (8) is arranged in the gas-liquid separation tower (6), the cyclone demister (9) is arranged in the gas-liquid separation tower (6) and is positioned at the top of the shower (8), and the wet electrostatic precipitator (10 ) is arranged on the top of the gas-liquid separation tower (6), and a chimney (11) is arranged on the top of the wet electrostatic precipitator (10), and the first output of the gas-liquid separation tower (6) passes through the power wave circulation pump (5) and pipeline Connect the second input of power wave scrubber (4); The second output of gas-liquid separation tower (6) is through the input of absorption circulation pump (7) and pipeline connection shower (8); Gas-liquid separation tower (6) ) the third output connection dehydration system; at the bottom of the gas-liquid separation tower (6) access oxidation air through the pipeline; The dehydration system comprises a gypsum discharge pump (13), a hydrocyclone (14) and a belt filter (15), and the third output of the gas-liquid separation tower (6) is connected to the hydrocyclone through the gypsum discharge pump (13) and a pipeline. The input of hydrocyclone (14), the first output and the second output of hydrocyclone (14) are connected the second input of gas-liquid separation tower (6) by pipeline, the 3rd output of hydrocyclone (14) Connect the input of belt filter (15) with the 4th output by pipeline, the product outlet output product of belt filter (15), the sewage outlet of belt filter (15) is connected pit (16) by pipeline ), the output of pit (16) is divided into the second input and sewage treatment station of gas-liquid separation tower (6) by vertical pump and pipeline in two ways. 2. The coal-fired boiler tail gas integrated desulfurization, denitrification, and dust removal treatment system according to claim 1, wherein the absorbent is formed by mixing process water and sodium hydroxide. 3. The coal-fired boiler tail gas integrated desulfurization, denitrification, and dust removal treatment system according to claim 1, characterized in that, in the batching box (12), the lower part of the gas-liquid separation tower (6) and the pit (16) A stirring shaft is set inside, and the stirring shafts are all driven by a motor. 4. The coal-fired boiler tail gas integrated desulfurization, denitrification, and dust removal treatment system according to claim 1, characterized in that water or slurry from the trench is injected into the pit (16). 5. The coal-fired boiler tail gas integrated desulfurization, denitrification, and dust removal treatment system according to claim 1, characterized in that a safety valve is set on the intake pipe of the ozone generator (2).