CN210874769U

CN210874769U - System for integrated synergistic removal of sulfur, nitrate and mercury in coal-fired flue gas dust

Info

Publication number: CN210874769U
Application number: CN201921107969.3U
Authority: CN
Inventors: 张杨; 刘青松; 陈艺秋; 陆超; 胡妲; 李佳晔; 张志中; 朱跃
Original assignee: Huadian Electric Power Research Institute Co Ltd
Current assignee: Huadian Electric Power Research Institute Co Ltd
Priority date: 2019-07-16
Filing date: 2019-07-16
Publication date: 2020-06-30
Anticipated expiration: 2029-07-16

Abstract

The utility model discloses a system of fire coal flue gas dirt sulphur nitre mercury integration desorption in coordination belongs to industrial waste gas purification environmental protection and energy field. The utility model discloses the system includes the boiler, and the boiler passes through flue and semidry process reactor intercommunication, and the semidry process reactor is connected with cyclone, and cyclone is connected with the dust remover, and the dust remover passes through draught fan and chimney intercommunication. The utility model discloses a NO and Hg in the coal-fired flue gas of sodium chlorite staged oxidation, then adopt quick lime as the absorbent in the flue gas of circulating fluidized bed semidry process reactor absorption sulphur nitre mercury, then realize the high-efficient desorption in coordination of integration of dirt sulphur nitre mercury in the sack cleaner, have that the system is simple reliable, investment and working costs are low, area advantage such as little, can produce good economic benefits and environmental protection benefit.

Description

System for integrated synergistic removal of sulfur, nitrate and mercury in coal-fired flue gas dust

Technical Field

The utility model belongs to industrial waste gas purifies environmental protection and energy field, in particular to system of fire coal flue gas dirt sulphur nitre mercury integration desorption in coordination.

Background

The energy structure mainly based on coal in China can not be changed for a long time, SO that the smoke dust and SO in the coal-fired flue gas are controlled₂、SO₃The discharge of pollutants such as NOx, Hg and the like is an important work for treating air pollution in China. The current coal-fired flue gas pollutant control method entering industrial application comprises SCR denitrationThe method comprises the following steps of limestone-gypsum wet desulphurization, an electric dust collector, a bag-type dust collector, activated carbon adsorption demercuration and the like, and although various technologies are used in a superposition manner, the pollutant emission concentration can be effectively controlled, the problems of large investment and occupied area of environmental protection facilities of a coal-fired power plant, high operation cost, large operation and maintenance workload and the like are caused. Therefore, the development of a technology capable of realizing the integrated synergistic removal of dust, sulfur, nitrate and mercury is a technical problem to be solved urgently in the technical field of the control of the pollutants in the coal-fired flue gas.

The Chinese patent related to the utility model, such as CN 103566725B-a circulating fluidized bed semidry method combined desulfurization, denitrification and demercuration device and method, injects ozone into the flue to oxidize NO and Hg in the flue gas, and then enters a circulating fluidized bed semidry method reactor to realize removal. However, the ozone is adopted as the oxidant, so that the problems of low oxidant utilization efficiency and high system energy consumption cost exist in the practical engineering application.

For example, CN 101785965B (CN 101785965B) -Integrated desulfurization and denitrification process and device by complexation-absorption circulation semi-dry method (SOx and NOx control) comprises spraying alkaline complexing agent into flue gas to absorb SO in flue gas₂And NO, and then enters a circulating fluidized bed semidry process reactor to realize removal. But the alkaline complexing agent is only for SO₂Has complexing absorption effect with NO, does not have absorption effect on Hg which is not easy to remove in smoke, and cannot realize effective removal of Hg.

SUMMERY OF THE UTILITY MODEL

The utility model aims at using to current coal fired power plant environmental protection facility stack, the investment is big with area, the working costs is high, the big scheduling problem of operation maintenance work load, provides a system of fire coal flue gas dirt nitre mercury integration desorption in coordination.

The utility model provides a technical scheme that above-mentioned problem adopted is: the system for integrated and collaborative removal of sulfur, nitrate and mercury in coal-fired flue gas dust comprises a boiler and is characterized in that the boiler is communicated with a semidry reactor through a flue, the semidry reactor is connected with a cyclone separator, the cyclone separator is connected with a dust remover, and the dust remover is communicated with a chimney through an induced draft fan; oxidant nozzles are arranged in the flue and the semidry method reactor, and the oxidant nozzles are communicated with the oxidant solution tank through pipelines; an absorbent nozzle is also arranged in the semidry method reactor, the absorbent nozzle is communicated with an absorbent tank through a pipeline, and the absorbent tank is communicated with a cyclone separator through a pipeline; the cyclone separator and the dust remover are both communicated with the ash storehouse.

Further, in the semi-dry process reactor, the oxidant nozzle is provided in plurality, and the plurality of oxidant nozzles are arranged in layers from top to bottom.

Further, the absorbent nozzle is arranged below the oxidant nozzle, and the oxidant nozzle is positioned above the flue gas inlet of the semi-dry process reactor.

Compared with the prior art, the utility model, have following advantage and effect: through the system, pollutants such as dust, sulfur, nitrate, mercury and the like in the flue gas can be removed integrally and synergistically, and the system has the advantages of simplicity and reliability, low investment and operation cost, small occupied area and the like, and can generate good economic benefit and environmental protection benefit.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

In the figure: the system comprises a boiler 1, a flue 2, a semidry reactor 3, a cyclone separator 4, a dust remover 5, an induced draft fan 6, a chimney 7, an oxidant solution tank 8, an ash storehouse 9, an oxidant nozzle 10, an absorbent nozzle 11 and an absorbent tank 12.

Detailed Description

The present invention will be described in further detail by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not intended to limit the present invention.

Referring to fig. 1, the system for integrated and collaborative removal of sulfur, nitrate and mercury in coal-fired flue gas dust in the embodiment comprises a boiler 1, wherein the boiler 1 is communicated with a semidry reactor 3 through a flue 2, the semidry reactor 3 is connected with a cyclone separator 4, the cyclone separator 4 is connected with a dust remover 5, and the dust remover 5 is communicated with a chimney 7 through an induced draft fan 6; an oxidant nozzle 10 is arranged in the flue 2 and the semi-dry method reactor 3, and the oxidant nozzle 10 is communicated with an oxidant solution tank 8 through a pipeline; an absorbent nozzle 11 is also arranged in the semi-dry method reactor 3, the absorbent nozzle 11 is communicated with an absorbent tank 12 through a pipeline, and the absorbent tank 12 is communicated with the cyclone separator 4 through a pipeline; in the semi-dry process reactor 3, a plurality of oxidant nozzles 10 are provided, and the plurality of oxidant nozzles 10 are arranged in layers from top to bottom; the absorbent nozzle 11 is arranged below the oxidant nozzle 10, and the oxidant nozzle 10 is positioned above the flue gas inlet of the semi-dry process reactor 3; the cyclone 4 and the dust collector 5 are both communicated with an ash storehouse 9.

The working method is that after the flue gas is discharged from the boiler 1, the flue gas and the sprayed oxidant generate pre-oxidation reaction in the flue 2, and then the flue gas enters the semi-dry reactor 3; the absorbent in the absorbent tank 12 is sprayed into the semidry reactor 3 through compressed air, and is in a suspension fluidization state under the action of flue gas to adsorb mercury, sulfur, nitrate and mercury; the oxidant is sprayed into the semidry process reactor 3 through the oxidant nozzle 10 in a grading atomization manner, so that the sulfur, nitrate and mercury in the flue gas are subjected to oxidation reaction, and the absorption of the absorbent is promoted; after being discharged from the semidry reactor 3, the flue gas enters the cyclone separator 4 to separate most of solid particles, most of the separated solid particles enter the absorbent tank 12 again for recycling, and the rest solid particles are conveyed to the ash storehouse 9 through pneumatic conveying; the flue gas then enters a bag-type dust collector 5 for dust removal, sulfur, nitrate and mercury are synchronously removed, and then the flue gas enters a chimney 7 through a draught fan 6, so that the pollutant is finally discharged after reaching the standard.

Wherein the oxidant is sodium chlorite and the absorbent is quicklime.

The pH value of the sodium chlorite solution sprayed into the flue 2 is controlled to be 3-6, and the molar ratio of the sodium chlorite solution to the nitre and mercury in the flue gas is controlled to be 0.5-1.

The pH value of the sodium chlorite solution sprayed into the semidry method reactor 3 is controlled to be 1-3, and the molar ratio of the sodium chlorite solution to the nitromercury in the flue gas is controlled to be 1-3.

The molar ratio of the quicklime sprayed into the semidry method reactor 3 to the sulfur and nitrate in the flue gas is controlled to be 1.1-2.0.

The separation efficiency of the cyclone separator 4 is more than 99%, 80-90% of the solid particles separated by the cyclone separator 4 enter the absorbent tank 12 again, and the rest solid particles are conveyed to the ash storehouse 9 by air.

Although the present invention has been described with reference to the above embodiments, it should not be construed as being limited to the scope of the present invention, and any modifications made by those skilled in the art without departing from the spirit and scope of the present invention should be construed as being included in the following claims.

Claims

1. A system for integrated and collaborative removal of sulfur, nitrate and mercury in coal-fired flue gas dust comprises a boiler (1) and is characterized in that the boiler (1) is communicated with a semi-dry reactor (3) through a flue (2), the semi-dry reactor (3) is connected with a cyclone separator (4), the cyclone separator (4) is connected with a dust remover (5), and the dust remover (5) is communicated with a chimney (7) through an induced draft fan (6); oxidant nozzles (10) are arranged in the flue (2) and the semidry method reactor (3), and the oxidant nozzles (10) are communicated with an oxidant solution tank (8) through pipelines; an absorbent nozzle (11) is further arranged in the semi-dry method reactor (3), the absorbent nozzle (11) is communicated with an absorbent tank (12) through a pipeline, and the absorbent tank (12) is communicated with the cyclone separator (4); the cyclone separator (4) and the dust remover (5) are both communicated with an ash storage (9).

2. The system for integrated and synergistic removal of sulfur, nitrate and mercury from coal-fired flue gas dust according to claim 1, characterized in that a plurality of oxidant nozzles (10) are arranged in the semidry reactor (3), and the oxidant nozzles (10) are arranged in layers from top to bottom.

3. The system for the integrated and synergistic removal of sulfur, nitrate and mercury from coal-fired flue gas dust according to claim 2, characterized in that the absorbent nozzle (11) is arranged below the oxidant nozzle (10), and the oxidant nozzle (10) is positioned above the flue gas inlet of the semi-dry process reactor (3).