Flue gas treatment device

Patent metadata

Field	Value
Publication number	US-2016243498-A1
Application number	US-201515025783-A
Country	US
Kind code	A1
Filing date	Jan 22, 2015
Priority date	Jan 31, 2014
Publication date	Aug 25, 2016
Grant date	—

Abstract

Provided are: an NOx removal unit to remove nitrogen oxide; an air preheater on a downstream side of the NOx removal unit to recover heat; a precipitator on a downstream side of the air preheater to remove ash dust; a gas-liquid contact type desulfurization unit on a downstream side of the precipitator to remove sulfur oxide; an SO 3 removing agent supply unit to supply an SO 3 removing agent at a supply unit on an upstream side of the precipitator; and a wet state processing unit between the air preheater and the supply unit to supply water to a flue gas to be made into a wet state; the wet state processing unit having a stand-up portion, a partition unit and a droplet supply unit.

First claim

1 - 13 . (canceled)

14 . A flue gas treatment device, comprising:
an NOx removal unit configured to remove nitrogen oxide contained in a flue gas flowing from a boiler; an air preheater that is provided on a downstream side of the NOx removal unit and is configured to recover heat in a flue gas after removal of nitrogen oxide; a precipitator that is provided on a downstream side of the air preheater and is configured to remove ash dust contained in a flue gas after heat recovery; a gas-liquid contact type desulfurization unit that is provided on a downstream side of the precipitator and is configured to remove sulfur oxide contained in a flue gas after precipitation; an SO 3 removing agent supply unit configured to supply an SO 3 removing agent to a flue gas inside a flue gas duct at a supply unit located on an upstream side of the precipitator; and a wet state processing unit that is provided between the air preheater and the supply unit that supplies the SO 3 removing agent and is configured to supply-water to a flue gas to be made into a wet state inside the flue gas duct, wherein the wet state processing unit includes a stand-up portion standing in a direction orthogonal to the flue gas duct configured to exhaust the flue gas, a partition unit configured to partition the inside of the stand-up portion into a gas ascending passage and a gas descending passage, and a droplet supply unit configured to supply droplets onto the gas descending passage partitioned by the partition unit.

15 . The flue gas treatment device according to claim 14 , wherein a hopper is provided on a lower side of the stand-up portion to remove solids in the flue gas duct.

16 . The flue gas treatment device according to claim 14 , comprising a line that extends from the desulfurization unit and supplies desulfurization wastewater from the desulfurization unit or dehydrated filtrate to the wet state processing unit.

17 . The flue gas treatment device according to claim 14 , comprising an Hg removing agent supply unit that is provided on an upstream side of the precipitator and is configured to supply an Hg removing agent to a flue gas.

18 . The flue gas treatment device according to claim 14 , comprising a return line that extends from the precipitator and is configured to combine a part of precipitated ash containing an SO 3 removing agent collected by the precipitator with the SO 3 removing agent from the SO 3 removing agent supply unit or a flue gas in the vicinity of the supply unit that supplies the SO 3 removing agent.

19 . The flue gas treatment device according to claim 14 , comprising a gas-gas heater that is provided between the supply unit that supplies the SO 3 removing agent and the precipitator and is configured to perform heat exchange of heat of a flue gas after heat recovery.

20 . A flue gas treatment device, comprising:
an NOx removal unit configured to remove nitrogen oxide contained in a flue gas flowing from a boiler; an air preheater that is provided on a downstream side of the NOx removal unit and is configured to recover heat in a flue gas after removal of nitrogen oxide; a gas-gas heater that is provided on a downstream side of the air preheater and is configured to perform heat exchange of heat of a flue gas after heat recovery; a precipitator that is provided on a downstream side of the gas-gas heater and is configured to remove ash dust contained in a flue gas after heat exchange; a gas-liquid contact type desulfurization unit that is provided on a downstream side of the precipitator and is configured to remove sulfur oxide contained in a flue gas after precipitation; an SO 3 removing agent supply unit configured to supply an SO 3 removing agent in a flue gas inside a flue gas duct at a supply unit located on a downstream side of the air preheater and located on an upstream side of the gas-gas heater; and a wet state processing unit that is provided between the gas-gas heater and the supply unit that supplies the SO 3 removing agent and is configured to supply water to a flue gas to be made into a wet state inside the flue gas duct, wherein the wet state processing unit includes a stand-up portion standing in a direction orthogonal to the flue gas duct configured to exhaust the flue gas, a partition unit configured to partition the inside of the stand-up portion into a gas ascending passage and a gas descending passage, and a droplet supply unit configured to supply droplets onto the gas descending passage partitioned by the partition unit.

21 . The flue gas treatment device according to claim 20 , wherein a hopper is provided on a lower side of the stand-up portion to remove solids in the flue gas duct.

22 . The flue gas treatment device according to claim 20 , comprising a line that extends from the desulfurization unit and supplies desulfurization wastewater from the desulfurization unit or dehydrated filtrate to the wet state processing unit.

23 . The flue gas treatment device according to claim 20 , comprising an Hg removing agent supply unit that is provided on an upstream side of the precipitator and is configured to supply an Hg removing agent to a flue gas.

24 . The flue gas treatment device according to claim 20 , comprising a return line that extends from the precipitator and is configured to combine a part of precipitated ash containing an SO 3 removing agent collected by the precipitator with the SO 3 removing agent from the SO 3 removing agent supply unit or a flue gas in the vicinity of the supply unit that supplies the SO 3 removing agent.

25 . The flue gas treatment device according to claim 18 , wherein the return line is provided with a specific gravity separator configured to separate the removing agents from the precipitated ash utilizing specific gravity.

26 . The flue gas treatment device according to claim 14 , wherein the droplet supply unit is provided with a soot removal device configured to drop solids adhered to a periphery of the droplet supply unit.

27 . The flue gas treatment device according to claim 14 , wherein a unit configured to detect a concentration of SO 3 in the flue gas is provided between the precipitator and the desulfurization unit.

28 . The flue gas treatment device according to claim 24 , wherein the return line is provided with a specific gravity separator configured to separate the removing agents from the precipitated ash utilizing specific gravity.

29 . The flue gas treatment device according to claim 20 , wherein the droplet supply unit is provided with a soot removal device configured to drop solids adhered to a periphery of the droplet supply unit.

30 . The flue gas treatment device according to claim 20 , wherein a unit configured to detect a concentration of SO 3 in the flue gas is provided between the precipitator and the desulfurization unit.

Assignees

• Mitsubishi Hitachi Power Sys

Inventors

• Kamiyama Naoyuki
• Kagawa Seiji
• Fukuda Toshihiro
• Ushiku Tetsu

Classifications

• B01D53/50 Primary

  Sulfur oxides (B01D53/60 takes precedence) · CPC title

• B01D53/56

  Nitrogen oxides (B01D53/60 takes precedence) · CPC title

• F23L15/04

  Arrangements of recuperators · CPC title

• B01D53/64

  Heavy metals or compounds thereof, e.g. mercury · CPC title

• F23J15/04

  using washing fluids {(scrubbers for removing solids only F23J15/022)} · CPC title