High-efficiency flue gas downstream dust removal, desulfurization and whitening method and device

Abstract

The invention discloses a high-efficiency flue gas downstream dust removal, desulfurization and whitening device comprising a spray scrubbing tower, high-level spray layers, low-level spray layers, adownstream Venturi gas-liquid uniform distributor, a rotational flow gas-liquid separator, a downstream tower type demister, oxidizing fans, an oxidizing air distribution device, a flow-equalizing pore plate, slurry disturbance pumps, a slurry turbulence distributor, slurry feeding pumps, a slurry feeding distributor, cooling slurry circulating pumps, cooling water heat exchangers, freezing slurrycirculating pumps, freezing water heat exchangers and slurry discharge pumps. The upper part of a tower body of the spray scrubbing tower is provided with a flue gas inlet, and a flue gas outlet is arranged in the middle of the tower body; an absorption liquid enters the tower from the upper spray layers and falls into a lower slurry pool, the absorption liquid flows in the same direction as fluegas, and a downstream flow is formed. Integrated effective removal of multiple pollutants is achieved by downstream spraying, and the device is suitable for dust removal, desulfurization (acid removal) and whitening treatment of flue gas and tail gas, and can be widely applied in the fields of air pollution prevention and control of thermal power, steel, non-ferrous metals and the like.

Description

technical field [0001] The invention relates to the technical field of flue gas tail gas treatment, in particular to a high-efficiency downstream dedusting and desulfurization (acid removal) whitening spray device and a treatment method thereof. It is suitable for dust removal, desulfurization (acid removal) and whitening treatment of flue gas and tail gas, and can be widely used in the fields of air pollution prevention and control in thermal power, steel, non-ferrous metals, etc. Background technique [0002] At present, in order to control the discharge of multiple pollutants, a combination of multiple pollutant control methods is generally adopted, that is, four separate sets of dry dust removal, denitrification, desulfurization, and wet electric dust removal are combined. Many power plants control NOX emissions by installing selective catalytic reduction denitrification devices (SCR), but the catalyst in the SCR device will catalytically oxidize part of SO2 in the flue ...

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Problems solved by technology

[0005] (1) The flue gas flow in the tower is reversed to the removal process of particulate matter, acid gas and other pollutants, and the flue gas is discharged with a large amount of pollutants, which reduces the purification efficiency, especially for PM2.5, which has basically no purification effect

[0006] (2) The flue gas flow in the tower is in the same direction as the buoyancy force of water vapor, which accelerates the escape of water vapor, aggravates the entrainment of droplets in the flue gas, and causes serious smoke plume

[0007] (3) The temperature and humidity change process of the flue gas in the tower (from top to bottom, the temperature gradually increases and the humidity gradually decreases) and the heterogeneous nucleation phase transition of pollutants (dust, condensed water and aerosol) The particle size increase process (from top to bottom, the temperature gradually decreases and the humidity gradually increases) is opposite, resulting in the inability to remove pollutants with small particle sizes (dust, condensed water and aerosols)

The better the atomization effect of the slurry, the lower the pollutant purification efficiency may be, especially the more serious smoke plume

[0008] (4) It is impossible to realize multiple functions of one tower, and the structure of the flue is complex. Under the premise of ensuring the purification efficiency, the construction investment is large and the operating cost is high

[0009] (5) The utilization rate of the absorption liquid is low and the operating cost is high

[0010] (6) The system occupies a large area, which is not conducive to the implementation of environmental protection facility renovation projects

[0011] (7) The stability of the system is low, the air leakage rate is high, and the operation, control, and maintenance are not easy enough

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