High velocity integrated flue gas treatment scrubbing system

• US 5,787,821 A
• Filed: 04/30/1997
• Issued: 08/04/1998
• Est. Priority Date: 02/13/1996
• Status: Expired due to Fees

• Current Assignee: Babcock & Wilcox Company (Babcock International Group PLC)
• Original Assignee: Babcock & Wilcox Company (Babcock International Group PLC)
• Inventors: Johnson, Dennis W., Myers, Robert B., Bhat, Pervaje A.
• Primary Examiner(s): Bennett, Henry A.
• Assistant Examiner(s): Lu, Jiping
• Application Number:
  US08/848,331
• Time in Patent Office: 461 Days
• Field of Search: 110/215, 110/216, 110/217, 55/222, 55/257.2, 55/257.7, 261/111, 261/127
• US Class Current: 110/216
• CPC Class Codes: B03C 3/017 Combinations of electrostatic separation with other processes, not otherwise provided for
• CPC Class Codes: F23J 15/006 Layout of treatment plant
• CPC Class Codes: F23J 2217/102 electrostatic
• CPC Class Codes: F23J 2219/40 Sorption with wet devices, e.g. scrubbers
• CPC Class Codes: F23J 2219/70 Condensing contaminants with coolers

Abstract

An integrated flue gas treatment desulfurization system for treating flue gas exhausted from an electrostatic precipitator and passing at a flue gas flow velocity in the range of 10-20 ft./sec. or more through a condensing heat exchanger and a wet flue gas scrubber. The scrubber sprays a reagent throughto the flue gas effectively remove pollutants and metals prior to exhausting same in a dry form after treatment by mist eliminators located downstream of the system.

Claims

1. A flue gas heat and recovery pollutant removal system, comprising:

an electrostatic precipitator situated to receive a high velocity flue gas flow and remove particulate therefrom;

a condensing heat exchanger assembly located to have high velocity flue gas flow downward therethrough, said condensing heat exchanger assembly being located downstream from said electrostatic precipitator and connected thereto, said condensing heat exchanger assembly lowering a temperature of the high velocity flue gas to below its dew point;

a plurality of nozzles for spraying reagent and water into the high velocity flue gas, said nozzles being situated below said condensing heat exchanger assembly;

a second series of spray nozzles positioned below said plurality of nozzles for spraying liquid reagent into the high velocity flue gas to remove pollutants therefrom;

a sieve tray positioned beneath said second series of nozzles for receiving spray therefrom and condensate from said condensing heat exchanger assembly;

a vertical chamber having oxidation air holes at one end and connected to said condensing heat exchanger assembly at the other end, said vertical chamber containing said plurality of nozzles, said second series of spray nozzles and said sieve tray;

a mist eliminator located downstream from said vertical chamber for removing any liquid droplets in the flue gas; and

a short wet stack exhaust connected to said vertical chamber for exhausting the flue gas.

2. A system as set forth in claim 1, further comprising a final mist eliminator stage located in said short wet stack to catch any water droplets in the flue gas.