Abstract: An air pollution control device is an air pollution control device for reducing the amounts of NOx and Hg contained in flue gas 12 from a boiler 11. The air pollution control device includes: NH4Cl solution supply means 16 for spraying an NH4Cl solution 14 by a spray nozzle 15 into a flue gas duct 13 at the downstream of the boiler 11; a mixer 17 provided on the downstream side of a region where NH4Cl is gasified, for promoting mixing, with the flue gas 12, HCl and NH3 which are generated when NH4Cl is gasified; a reduction-denitration device 18 including a denitration catalyst for reducing NOx in the flue gas 12 with NH3 and for oxidizing Hg under the coexistence with HCl; and a wet desulfurization device 22 for reducing the amount of Hg oxidized in the reduction-denitration device 18 using a limestone-gypsum slurry 21.

Abstract: A mercury reduction system includes an NH4Cl supplying unit that sprays an NH4Cl solution into a flue of the boiler, a reduction denitration apparatus that includes a denitration catalyst for reducing NOx in the flue gas with NH3 and oxidizing Hg in the presence of HCl, and a wet desulfurization apparatus for reducing Hg oxidized in the reduction denitration apparatus with limestone-gypsum slurry. The NH4Cl supplying unit includes an NH4Cl solution feed pipe that supplies the NH4Cl solution into the flue in a liquid state, a blow pipe that is inserted into the flue so as to surround the NH4Cl solution feed pipe and through which air is injected into the flue, and a two-fluid nozzle that is fitted to an end of the NH4Cl solution feed pipe and through which the NH4Cl solution is injected. Through the two-fluid nozzle, the NH4Cl solution is injected and sprayed in fine liquid droplets.

Abstract: An air pollution control system 10A includes a boiler 11 that burns fuel, an air heater 13 that recovers heat of flue gas 17 from the boiler 11, and a desulfurizer 15 that reduces sulfur oxides contained in the flue gas 17 after heat recovery by an absorbent, and waste-water supplying units P0 to P5 that supply desulfurized waste water 28 discharged from the desulfurizer 15 to at least one of a path for supplying fuel to the boiler 11, inside of a furnace of the boiler 11, and the inside of a flue gas duct between the boiler 11 and the air heater 13 are installed. With this configuration, an amount of desulfurized waste water to be returned into the flue gas duct per unit time can be increased as compared to conventional systems, without increasing the size of the entire air pollution control system.

Abstract: An air pollution control system 10A according to the present invention includes: a boiler 11 that burns fuel; NOx removal equipment 12 that decomposes nitrogen oxides in flue gas 25 discharged from the boiler 11; a desulfurizer 15 that causes sulfur oxides in the flue gas 25 having passed through the NOx removal equipment 12 to be absorbed by an absorbent, thereby reducing sulfur oxides in the flue gas 25, a waste-water treatment device 16 including a solid-liquid separating unit 31 that separates desulfurized waste water 28 discharged from the desulfurizer 15 into a solid fraction and a liquid fraction, and a mercury removing unit 32 that removes mercury in the desulfurized waste water 28; and a treated waste-water returning unit (a makeup water line) 17 that returns at least a part of treated waste water 40 treated by the waste-water treatment device 16 to the desulfurizer 15.

Abstract: An air pollution control system comprises: a carry-in tank truck that carries in a feedstock, i.e., concentrated hydrochloric acid (35% hydrochloric acid); a hydrogen chloride vaporizer that vaporizes the concentrated hydrochloric acid to obtain hydrogen chloride; a liquid level regulator that separates residual hydrogen chloride from extracted dilute hydrochloric acid discharged as a by-product from the hydrogen chloride vaporizer, and that regulates the liquid level of the hydrogen chloride vaporizer; a concentration regulating tank that regulates the hydrochloric acid concentration of extracted dilute hydrochloric acid 25B from which the residual hydrogen chloride has been separated to a predetermined concentration (e.g., 22%); a by-product tank that stores therein dilute hydrochloric acid regulated to have a predetermined concentration; and a carry-out tank truck that carries out the dilute hydrochloric acid with a predetermined concentration discharged from the by-product tank.

Abstract: In a heat exchanger that includes an expanded part of a duct, a heat-transfer tube bundle accommodating duct, and a plurality of heat-transfer tube bundles provided in the heat-transfer tube bundle accommodating duct in a flow direction of flue gas with a distance therebetween, a bare-tube-part upstream-side regulating plate and a bare-tube-part downstream-side regulating plate at an upstream side and a downstream side of a bare tube part of each of the heat-transfer tube bundles and a plurality of regulating plates in an introducing unit arranged either in the expanded part of a duct or in the heat-transfer tube bundle accommodating duct on an upstream side to the heat-transfer tube bundle are provided. A drift at the bare tube part of the heat-transfer tube bundles can be significantly reduced.

Abstract: An air pollution control apparatus includes at least one denitration catalyst layer for reducing the amounts of nitrogen oxides in flue gas from a boiler and oxidizing mercury with hydrogen chloride sprayed into the flue gas. Spraying pipe headers 51 are disposed in a flue gas duct 19. The spraying pipe headers 51 are inserted into the flue gas duct 19 and arranged in a direction orthogonal to the direction of a gas flow in the flue gas duct 19. At least four spray nozzles 52-1 to 52-4 are disposed on the spraying pipe header 51 to form a vertical vortex flow 53 in the gas flow direction. The diffusion of hydrogen chloride is thereby facilitated in a rapid manner. Therefore, the number of the nozzles can be reduced, and the uniformity of the concentration of hydrogen chloride at the location of the catalyst can be ensured even when the spacing between the nozzles is increased.

Abstract: An air pollution control apparatus 10 according to an embodiment of the present invention has a denitration catalyst layer 13 that removes nitrogen oxides in flue gas, and atomizes hydrochloric acid into flue gas to oxidize mercury, and also includes a swirling-flow generating member 15A including a vertical axis 22 provided in a passage 14 of a honeycomb catalyst, and four swirling-flow generating vanes 23 provided radially with respect to the vertical axis 22 for generating a turbulent flow in flue gas, with the swirling-flow generating vanes 23 being arranged in a direction of the vertical axis 22 with a predetermined gap therebetween. With this configuration, by generating a swirling flow in flue gas in the passage 14 in the denitration catalyst layer 13, a contact time between flue gas and a denitration catalyst can be increased, and the oxidation reaction efficiency between mercury in flue gas and the denitration catalyst can be improved.

Abstract: An air pollution control apparatus 10 according to an embodiment of the present invention has a denitration catalyst layer 13 that removes NOx in flue gas 12, and atomizes HCl into the flue gas 12 to oxidize Hg, and also includes a swirling-flow generating member 30A that includes a swirling-flow generating-member body being partitioned to correspond to each passage of the denitration catalyst layer 13 and a plurality of swirling-flow generating vanes arranged on the partition inner walls to generate a turbulent flow, on an inlet 13a side of the denitration catalyst layer 13. With this configuration, a laminar flow of the flue gas 12 in a flue gas duct 19 is changed to a swirling flow, thereby enabling to increase a contact time between the flue gas 12 and a denitration catalyst and to improve the oxidation reaction efficiency between Hg in the flue gas 12 and the denitration catalyst.

Abstract: A mercury reduction system according to the present embodiment is a mercury reduction system that reduces NOx and Hg in flue gas discharged from a boiler, and includes an NH4Cl solution spraying unit that sprays an NH4Cl solution into a flue of the boiler in a liquid state, a mixed gas spraying unit that is provided downstream of the NH4Cl solution spraying unit and sprays mixed gas containing NH3 gas and HCl gas into the flue, a reduction denitration apparatus that includes a denitration catalyst reducing NOx in the flue gas with NH3 and oxidizing Hg in the presence of HCl, and a wet desulfurization apparatus that reduces Hg oxidized in the reduction denitration apparatus with a limestone-gypsum slurry.

Abstract: A mercury reduction system according to the present embodiment is a mercury reduction system that reduces NOx and Hg in flue gas discharged from a boiler, and includes a chemical supplying unit that mixes an NH4Cl solution, an NH3 solution, and an HCl solution in liquid states, and supplies a mixed solution into a flue provided downstream of the boiler, a reduction denitration apparatus that includes a denitration catalyst reducing NOx in the flue gas with NH3 and oxidizing Hg in the presence of HCl, and a wet desulfurization apparatus that reduces Hg oxidized in the reduction denitration apparatus with limestone-gypsum slurry.

Abstract: A mercury reduction system includes an NH4Cl supplying unit that sprays an NH4Cl solution into a flue of the boiler, a reduction denitration apparatus that includes a denitration catalyst for reducing NOx in the flue gas with NH3 and oxidizing Hg in the presence of HCl, and a wet desulfurization apparatus for reducing Hg oxidized in the reduction denitration apparatus with limestone-gypsum slurry. The NH4Cl supplying unit includes an NH4Cl solution feed pipe that supplies the NH4Cl solution into the flue in a liquid state, a blow pipe that is inserted into the flue so as to surround the NH4Cl solution feed pipe and through which air is injected into the flue, and a two-fluid nozzle that is fitted to an end of the NH4Cl solution feed pipe and through which the NH4Cl solution is injected. Through the two-fluid nozzle, the NH4Cl solution is injected and sprayed in fine liquid droplets.

Abstract: A mercury reduction system according to the present embodiment is a mercury reduction system that reduces NOx and Hg in flue gas discharged from a boiler, and includes a chemical supplying unit that mixes an NH4Cl solution, an NH3 solution, and an HCl solution in liquid states, and supplies a mixed solution into a flue provided downstream of the boiler, a reduction denitration apparatus that includes a denitration catalyst reducing NOx in the flue gas with NH3 and oxidizing Hg in the presence of HCl, and a wet desulfurization apparatus that reduces Hg oxidized in the reduction denitration apparatus with limestone-gypsum slurry.

Abstract: A mercury reduction system according to the present embodiment is a mercury reduction system that reduces NOx and Hg in flue gas discharged from a boiler, and includes an NH4Cl solution spraying unit that sprays an NH4Cl solution into a flue of the boiler in a liquid state, a mixed gas spraying unit that is provided downstream of the NH4Cl solution spraying unit and sprays mixed gas containing NH3 gas and HCl gas into the flue, a reduction denitration apparatus that includes a denitration catalyst reducing NOx in the flue gas with NH3 and oxidizing Hg in the presence of HCl, and a wet desulfurization apparatus that reduces Hg oxidized in the reduction denitration apparatus with a limestone-gypsum slurry.

Abstract: According to the present invention, a heat transfer tube monitoring apparatus for use in a heat exchanger including multiple-stage heat transfer tube bundles spaced apart from each other in a flow direction of flue gas includes a differential pressure detecting unit used for detecting a differential pressure between upstream and downstream for each of the heat transfer tube bundles. With this configuration, an abnormal heat transfer tube bundle can be specified.

Abstract: An air pollutant control system comprises: a denitration apparatus that reduces nitrogen oxide in flue gas discharged from a coal combustion boiler, and that sprays hydrogen chloride into the gas to oxidize mercury, an air heater that recovers heat in gas, a dust collector that reduces dust in gas, a desulfurization apparatus that reduces sulfur oxide in gas from which the dust has been reduced, a hydrogen chloride vaporizer that evaporates concentrated hydrochloric acid to obtain the hydrogen chloride, and a hydrochloric acid neutralization tank where dilute hydrochloric acid discharged from the hydrogen chloride vaporizer or the concentrated hydrochloric acid is neutralized with an alkali agent. Neutralized chloride is supplied to a fuel feeder, mixed with a fuel, and then burned as a fuel in a boiler to produce hydrogen chloride in flue gas. Together with sprayed hydrogen chloride derived from the hydrogen chloride vaporizer, the mercury is reduced.

Abstract: An air pollutant control system comprises: a denitration apparatus that reduces nitrogen oxide in flue gas discharged from a coal combustion boiler, and that sprays hydrogen chloride into the gas to oxidize mercury, an air heater that recovers heat in gas, a dust collector that reduces dust in gas, a desulfurization apparatus that reduces sulfur oxide in gas from which the dust has been reduced, a hydrogen chloride vaporizer that evaporates concentrated hydrochloric acid to obtain the hydrogen chloride, and a hydrochloric acid neutralization tank where dilute hydrochloric acid discharged from the hydrogen chloride vaporizer or the concentrated hydrochloric acid is neutralized with an alkali agent. Neutralized chloride is supplied to a fuel feeder, mixed with a fuel, and then burned as a fuel in a boiler to produce hydrogen chloride in flue gas. Together with sprayed hydrogen chloride derived from the hydrogen chloride vaporizer, the mercury is reduced.

Abstract: An air pollution control system comprises: a carry-in tank truck that carries in a feedstock, i.e., concentrated hydrochloric acid (35% hydrochloric acid); a hydrogen chloride vaporizer that vaporizes the concentrated hydrochloric acid to obtain hydrogen chloride; a liquid level regulator that separates residual hydrogen chloride from extracted dilute hydrochloric acid discharged as a by-product from the hydrogen chloride vaporizer, and that regulates the liquid level of the hydrogen chloride vaporizer; a concentration regulating tank that regulates the hydrochloric acid concentration of extracted dilute hydrochloric acid 25B from which the residual hydrogen chloride has been separated to a predetermined concentration (e.g., 22%); a by-product tank that stores therein dilute hydrochloric acid regulated to have a predetermined concentration; and a carry-out tank truck that carries out the dilute hydrochloric acid with a predetermined concentration discharged from the by-product tank.