CN210845850U - A device for the removal of heavy metals from arsenic, selenium, lead and heavy metals by lye jet boosting WESP - Google Patents

Abstract

The utility model relates to a device for removing heavy metals such as arsenic, selenium, and lead by lye spraying and lifting WESP. The device comprises a cylinder body. The cylinder body is provided with a sewage discharge area, a two-stage spray area, an electrostatic dust removal area and an adsorption area in sequence from bottom to top. There is a flue gas outlet on the top of the body, and the two-stage spray area has a first-level spray area and a second-level spray area arranged in sequence from bottom to top. There is a flue gas inlet below the primary spray area of the cylinder. Compared with the prior art, for the effective removal of pollutant particles, heavy metals, arsenic, selenium, and lead in the flue gas, the flue gas passes through the first-level spray area, the demisting area, the second-level spray area, and the static electricity in sequence. In the dust removal area and the adsorption area, the wet electrostatic precipitator with double-stage spraying lye and the micron-scale porous adsorption are used to synergistically treat the heavy metals arsenic, selenium and lead in the flue gas, so as to efficiently remove various forms of arsenic, selenium and lead in the flue gas. The removal rate of heavy metals is improved as a whole, and the ultra-low and near-zero emission of coal-fired flue gas is realized.

Description

A device for the removal of heavy metals from arsenic, selenium, lead and heavy metals by lye jet boosting WESP

technical field

The utility model relates to the technical field of wet electrostatic precipitators, in particular to a system for removing heavy metals such as arsenic, selenium, and lead by lye spraying and elevating WESP.

Background technique

With the development of the economy, the demand for electricity in industrial production and people's life continues to increase. Although my country is vigorously advocating energy-saving power generation and developing new energy and other measures, the coal-dominated energy structure in my country will not change in a short period of time. China is the largest coal producer and largest coal consumer in the world, and coal currently accounts for about 70% of the energy mix. However, coal combustion will produce a large amount of SO _x , NO _x and heavy metals, among which heavy metals such as arsenic, selenium, and lead are more harmful. These heavy metals are mainly concentrated on submicron particles and are difficult to be effectively used by conventional pollutant control facilities. Captured, they mainly exist in the form of aerosols in the atmosphere, which are not easy to settle, and most of the harmful heavy metals are difficult to be degraded by microorganisms, and stay in the atmosphere for a long time, causing great harm to the ecosystem and human beings.

my country's research on how to control heavy metals in coal-fired power plant purification devices started relatively late. At present, the research direction in the existing technology is mainly the determination of heavy metal content in flue gas, but how to improve the removal efficiency of heavy metals in flue gas and strengthen the There is still no perfect solution for the removal of heavy metals in China.

Therefore, in order to reduce the emission of heavy metal pollutants in the atmosphere of coal-fired power plants, and to carry out the form transformation, distribution and control of heavy metals in the process of coal combustion, various technologies need to be developed to remove particulate matter and heavy metals in flue gas. Chinese patent CN108201974A discloses a wet electrostatic precipitator, including a cleaning component and a chassis, an air inlet is provided on one side of the chassis, an air outlet is provided on the top of the chassis, and a sedimentation tank is provided below the chassis. The disadvantage of this technical solution is that the removal process of heavy metals is single, and the classification treatment cannot be realized, resulting in a low removal rate.

Utility model content

The purpose of the utility model is to provide a device for removing heavy metals from arsenic, selenium, and lead by lye spraying and elevating WESP in order to overcome the above-mentioned defects in the prior art.

The purpose of the present utility model can be achieved through the following technical solutions:

A device for removing heavy metals such as arsenic, selenium, and lead by lye spraying and lifting WESP, comprising a cylinder body, a sewage discharge area, a two-stage spray area, an electrostatic dust removal area and an adsorption area are sequentially arranged in the cylinder body from bottom to top, and the top of the cylinder body is provided with The flue gas outlet, the two-stage spray area has a first-level spray area and a second-level spray area sequentially arranged from bottom to top, and a demisting area is arranged between the first-level spray area and the second-level spray area , There is a flue gas inlet below the primary spray area of the cylinder.

As a preferred technical solution, the primary spray zone is used for the flue gas to contact the alkaline solution sprayed in the primary spray zone to remove heavy metals including arsenic, selenium and lead. The sprayed alkaline solution is a mixed alkaline solution of calcium hydroxide and sodium hydroxide.

As a preferred technical solution, the mass ratio of calcium hydroxide to sodium hydroxide is 1:1 to 3.

As a preferred technical solution, the secondary spraying area is used for the contact of flue gas with the alkaline solution sprayed in the secondary spraying area to further remove particulate, elemental and combined heavy metals; the secondary spraying area The sprayed alkaline solution is an alkaline solution prepared by sodium carbonate and sodium bicarbonate powder. The particulate heavy metals include particulate As _p , _{Sep and Pb p ,} and the elemental heavy metals include elemental Se ⁰ and Pb ⁰ . State heavy metals include As ³⁺ , As ⁵⁺ , Se ⁴⁺ and Pb ²⁺ in combined state.

As a preferred technical scheme, the mass ratio of sodium carbonate to sodium bicarbonate is 1:1～3.

As a preferred technical solution, the alkaline solution sprayed in the first-level spray area and the second-level spray area is an alkaline droplet of 10 μm-200 μm.

As a preferred technical solution, the mist removal area is provided with a mist eliminator, and the mist eliminator is used to treat fine dust particles, mist particles and wet gas saturated with liquid vapor.

As a preferred technical solution, the electrostatic precipitator area is provided with a central axis and an anode and a cathode which are alternately arranged and connected to the central axis, the cathode is provided with burrs, and the anode and the cathode are driven by the central axis to follow the central axis Periodic rotation. Improve the dust removal effect in the electrostatic dust removal area, and further improve the removal effect of the particles formed by the droplets such as arsenic, selenium, and lead after spraying.

As a preferred technical solution, the electrostatic precipitator area is also provided with a purging component, the purging component is a high-pressure air injector, located above the cathode and the anode, for purging the particles adsorbed on the electrode plate of the electrostatic precipitator area, so that the into the sewage area.

As a preferred technical solution, the adsorption zone is provided with an adsorption bed of micron-sized porous activated carbon and sodium bicarbonate. The use of sodium bicarbonate and activated carbon to further adsorb various forms of heavy metals such as arsenic, selenium, and lead.

As a preferred technical solution, the sewage area is provided with an ash hopper and a sewage outlet. It is used to collect particles of heavy metals such as arsenic, selenium, and lead.

As a preferred technical solution, the device also includes a guide plate arranged between the primary spray area and the second spray area and above the sewage area, and the guide plate is a porous guide plate for optimizing smoke Airflow field uniformity.

As a preferred technical solution, when the removal efficiency drops significantly, operations such as replacing the adsorption bed and updating the spray liquid are required.

When working, the flue gas enters the primary spray area from the flue gas inlet. The spray liquid used is a mixed alkaline solution of calcium hydroxide and sodium hydroxide. The flue gas is fully contacted with the spray liquid in the spray area. It is mixed with sodium hydroxide to further process heavy metals such as arsenic, selenium, and lead; the flue gas enters the demisting area after first-level spraying, where the mist eliminator treats fine dust particles, mist particles and wet gas saturated with liquid vapor; flue gas After passing through the defogging area, it enters the secondary spraying area. The spraying liquid used is an alkaline solution prepared by sodium carbonate and sodium bicarbonate powder. The flue gas is fully contacted with the spraying liquid in the spraying area. Further removal of particulate (As _p , _{Sep , Pb p )} , elemental (Se ⁰ , Pb ⁰ ) and combined (As ³⁺ , As ⁵⁺ , Se ⁴⁺ , Pb ²⁺ ) arsenic, selenium and lead The flue gas enters the electrostatic precipitator area after passing through the secondary spray area, in which the anode and the cathode with thorns are staggered and connected to the central shaft. During operation, the electrode rotates periodically with the central shaft to improve the dust removal in the electrostatic precipitator area. It can further improve the removal effect of arsenic, selenium, lead and other particles formed by droplets after spraying. Sodium bicarbonate and activated carbon are used to further adsorb various forms of heavy metals such as arsenic, selenium, and lead, and finally the purified flue gas is discharged from the flue gas outlet.

Compared with the prior art, the beneficial effect of the utility model is: for the effective removal of pollutant particles, heavy metals, arsenic, selenium, and lead in the flue gas, the flue gas passes through the first-level spray area, the demisting area, and the second-level spray area in turn. In the shower area, electrostatic precipitator area and adsorption area, the wet electrostatic precipitator with double-stage spraying lye and the micron-level porous adsorption are used to synergistically treat the heavy metals arsenic, selenium, and lead in the flue gas, so as to remove various forms of arsenic, selenium, and lead in the flue gas. High-efficiency removal improves the removal rate of heavy metals as a whole, and achieves ultra-low and near-zero emissions of coal-fired flue gas.

Description of drawings

FIG. 1 is a schematic diagram of a device for removing heavy metals such as arsenic, selenium, and lead by lye spraying and lifting WESP according to the present invention.

In the figure, 1 is the flue gas inlet, 2 is the primary spray area, 3 is the demister, 4 is the secondary spray area, 5 is the anode, 6 is the cathode, 7 is the thorn, 8 is the adsorption area, 9 It is a flue gas outlet, 10 is a guide plate, 11 is an ash hopper, 12 is a sewage outlet, and 321 is a purging part.

Detailed ways

The present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1

A device for removing heavy metals such as arsenic, selenium, and lead by lye spraying and elevating WESP, as shown in Figure 1, includes a cylinder, and the cylinder is provided with a sewage discharge area, a two-stage spray area, an electrostatic dust removal area and an adsorption area from bottom to top. 8. The top of the cylinder is provided with a flue gas outlet 9. The two-stage spray area has a first-level spray area 2 and a second-level spray area 4, and a first-level spray area 2 and a second-level spray area. A mist removal area is arranged between the areas 4, and a flue gas inlet 1 is arranged below the primary spray area 2 of the cylinder (and above the sewage discharge area).

specifically:

In this embodiment, the primary spraying area 2 is used for the flue gas to contact the alkaline solution sprayed by the primary spraying area 2 to remove heavy metals including arsenic, selenium and lead, and the primary spraying area sprays The alkaline solution is a mixed alkaline solution of calcium hydroxide and sodium hydroxide. The secondary spraying area 4 is used for the flue gas to contact the alkaline solution sprayed by the secondary spraying area 4 to further remove the particulate, elemental and combined heavy metals; the alkaline solution sprayed by the secondary spraying area 4 Alkaline solution prepared for sodium carbonate and sodium bicarbonate powder, particulate heavy metals include particulate As _p , _{Sep and Pb p ,} elemental heavy metals include elemental Se ⁰ and Pb ⁰ , combined heavy metals include combined As ³⁺ , As ⁵⁺ , Se ⁴⁺ and Pb ²⁺ . Preferably, the alkaline solution sprayed by the primary spraying area 2 and the secondary spraying area 4 is 10 μm-200 μm alkaline mist droplets. Further preferably, the mass ratio of calcium hydroxide to sodium hydroxide is 1:1 to 3, and the mass ratio of sodium carbonate to sodium bicarbonate is 1:1 to 3.

In this embodiment, a mist eliminator 3 is provided in the demisting area, and the mist eliminator 3 is used to treat fine dust particles, mist particles and wet gas saturated with liquid vapor.

In this embodiment, the electrostatic precipitator area is provided with a central axis and an anode 5 and a cathode 6 which are alternately arranged and connected to the central axis. The cathode 6 is provided with burrs 7, and the anode 5 and the cathode 6 follow the cycle of the central axis under the driving of the central axis. Sexual rotation. It is further preferred that the electrostatic precipitator area is also provided with a purging component 321, which is a high-pressure air ejector, located above the cathode 6 and the anode 5, and is used for purging the particles adsorbed on the electrode plate of the electrostatic precipitator area to make it into the sewage area.

In this embodiment, the adsorption zone 8 is provided with an adsorption bed of micron-sized porous activated carbon and sodium bicarbonate.

In this embodiment, the sewage area is provided with an ash hopper 11 and a sewage outlet 12 . It is used to collect particles of heavy metals such as arsenic, selenium, and lead.

In this example, the device further includes a deflector 10 disposed between the primary spray area 2 and the secondary spray area 4 and above the sewage area. The deflector 10 is a porous deflector for optimizing the flue gas. flow field uniformity.

The flue gas first enters the primary spray zone 2 from the flue gas inlet 1, and the flue gas passes through the deflector 10 to uniformize the flue gas flow field. The calcium hydroxide and sodium hydroxide droplets sprayed from the primary spray zone 2 are partially The heavy metal particles are combined to form larger particles and settle into the ash hopper 11, and further oxidize part of the heavy metals arsenic, selenium, and lead; then the flue gas passes through the demisting area and passes through the mist eliminator 3 to treat fine dust particles, mist particles and saturated with liquid vapor. The other part of the heavy metal particles in the flue gas enters the secondary spray zone 4, and fully contacts with the spray liquid sodium carbonate and sodium bicarbonate solution, and further removes various forms of heavy metals such as arsenic, selenium, and lead; then The remaining heavy metal particles enter the electrostatic precipitator area, and are partially adsorbed on the electrode plate after corona discharge. The electrode plate in the electrostatic precipitator area rotates periodically with the central axis, and the heavy metal particles adsorbed on the electrode are blown to the ash hopper through the blowing part 321 11. The heavy metal particles deposited at the ash hopper 11 are discharged from the sewage outlet 12; the flue gas enters the adsorption area 8 after passing through the electrostatic dust removal area, and the residual heavy metals in the flue gas are further adsorbed by the micron-sized porous activated carbon and sodium bicarbonate. The flue gas is finally discharged from the flue gas outlet 9. Taking heavy metal lead as an example, after 5-10 tests of the simulated flue gas system, the lead concentration at the flue gas inlet is 30 μg/m ³ , the overall error of the simulated experiment is ±5%, and the flue gas flow is set to 1.2 L/min. The average lead content detected in the flue gas after lye injection and adsorption of the device was 6.23 μg/m ³ .

The above description of the embodiments is for the convenience of those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications to these embodiments can be readily made, and the generic principles described herein can be applied to other embodiments without inventive step. Therefore, the present invention is not limited to the above-mentioned embodiments, and improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should all fall within the protection scope of the present invention.

Claims (5)

1. The utility model provides a device that alkali lye sprays and promotes WESP and takes off arsenic selenium lead heavy metal, includes the barrel, its characterized in that is equipped with blowdown district, doublestage spray district, electrostatic precipitator district and adsorption zone (8) from the bottom up in proper order in the barrel, and the barrel top is equipped with exhanst gas outlet (9), the doublestage spray the one-level that the district has from the bottom up and set gradually and spray district (2) and second grade and spray district (4), the one-level sprays and is equipped with between district (4) except that fog district, the one-level of barrel sprays and distinguishes (2) below and is equipped with flue gas inlet (1).

2. The device for removing arsenic, selenium and lead heavy metals by WESP through lye injection lifting as claimed in claim 1, wherein said demisting zone is provided with a demister (3), said demister (3) being used for treating fine dust particles, mist particles and wet gas saturated with liquid vapor.

3. The device for removing arsenic, selenium and lead heavy metals by WESP through lye jet lifting as claimed in claim 1, wherein said electrostatic precipitator is provided with a central shaft and anodes (5) and cathodes (6) alternately arranged and connected to the central shaft, said cathodes (6) are provided with barbs (7), and said anodes (5) and cathodes (6) are driven by the central shaft to periodically rotate along the central shaft.

4. The device for removing arsenic, selenium and lead heavy metals by WESP through lye jet lifting as claimed in claim 3, wherein the electrostatic precipitation zone is further provided with a purging component (321), the purging component (321) is a high pressure air injector, and is positioned above the cathode (6) and the anode (5) for purging the particles adsorbed on the electrode plate of the electrostatic precipitation zone to make them fall to the blowdown zone.

5. The device for removing arsenic, selenium and lead heavy metals by WESP through lye jet lifting as claimed in claim 1, wherein the device further comprises a guide plate (10) arranged between the primary spraying area (2) and the secondary spraying area (4) and above the sewage discharge area, and the guide plate (10) is a porous guide plate for optimizing the uniformity of the flue gas flow field.

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