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US 5,321,946 AGranted
Method and system for a condensing boiler and flue gas cleaning by cooling and liquefaction
OwnerFawzy T. Abdelmalekinventor
Life of this patent
Estimating the term…
Abstract
A method for cleaning a flue gas stream continuously emitting from a thermal power plant fossil fueled boiler, and containing hazardous volatile organic vapors, heavy metal vapors, nitrogen oxides, sulfur dioxide, and carbon dioxide by cooling, condensing and gas liquefaction processes employing a heat recovery condensing heat exchanging, and a gas compressor-expander open heat cycle systems.
Claims9
In combination with a fossil fueled power plant boiler system wherein the improvement allows cleanup of the flue gas stream by recovering thermal energy that otherwise would be lost to the atmosphere, and by employing a gas compressor-expander open heat cycle system, the improvement of which comprises:
- a thermal fossil fueled power plant boiler having a continuous combustion air stream and emitting a continuous flue gas stream containing particulate matter, hazardous volatile organic vapors, heavy metal vapors, acidic water vapors, nitric oxides, sulfur dioxide, carbon dioxide;
- conduits for conducting the said combustion air stream and the said flue gas stream;
- an electrostatic precipitator dust collection system to remove the said particulate matter;
- an electrostatic gas treater to neutralize the electromagnetic charges of the particulate matter released in the said flue gas stream flowing from the said electrostatic precipitator dust collection system;
- a condensing heat exchanger for recovering thermal energy from the flue gas stream to allow cooling and condensing water vapor contained therein while preheating combustion air stream;
- a gas seperator to seperate the flue gas stream flowing from the said condensing heat exchanger into a heavier flue gas fraction stream and a lighter flue gas fraction stream;
- a flue gas compressor-expander system consisting of a gas compressor, a gas expander, and a prime mover having a common drive shaft and drive controls to pressurize the said enriched carbon dioxide gas fraction and to expand the said pressurized gas stream into a reverse expanded gas stream;
- a heat exchanger to cool and condense part of the said acidic water vapors contained in the said pressurized enriched carbon dioxide gas fraction stream while heating an auxiliary cooling water stream;
- a first expanded reverse gas stream to a pressurized gas stream heat exchanger to further cool and condense the acidic water vapors contained in the pressurized flue gas stream while heating the expanded reverse gas stream flowing from a second reverse gas to gas heat exchanger;
- a first moisture separator to separate and remove the acidic water vapor condensate contained in the pressurized flue gas stream flowing from the said first reverse gas to gas heat exchanger;
- a second expanded reverse gas stream to a pressurized gas stream heat exchanger to further cool and condense most of the sulfur dioxide contained in the pressurized flue gas stream flowing from the first moisture separator while heating the expanded reverse gas stream flowing from a third reverse gas to has heat exchanger;
- a second moisture separator to separate and remove condensate of the liquefied sulfur dioxide gas contained in the said pressurized flue gas stream flowing from the said second gas to gas heat exchanger;
- a third expanded reverse gas stream to a pressurized gas stream heat exchanger to further cool and condense a part of the carbon dioxide contained in the pressurized flue gas stream flowing from the second moisture separator while further heating the expanded reverse gas stream flowing from the gas expander;
- a third moisture separator to separate and remove the condensate of the carbon dioxide gas contained in the pressurized flue gas stream flowing from the third reverse gas to gas heat exchanger;
- a liquid to liquid heat exchanger to allow normalizing the temperature of the said condensate products while chilling a cooling water stream;
- a water cooling tower flue gas diffusing system to allow further cleaning and releasing the lighter flue gas stream flowing from the said gas separator and the cleaned heavier flue gas stream flowing from the first reverse gas heat exchanger.
13 more elements
A process for cleaning a flue gas stream continuously emitting from a thermal power plant fossil fueled boiler and containing hazardous volatile organic vapors, heavy metal vapors, acidic water vapors, nitrogen oxides, sulfur dioxide, and carbon dioxide by cooling, and condensing processes employing a heat recovery condensing heat exchanging and a gas compressor-expander open heat cycle system;
- the improvement which comprises:
- cleaning the said flue gas stream by removing the particulate matter contained therein through an electrostatic precipitator dust collection system;
- neutralizing electromagnetic charges of the volatile organic and heavy metal vapors, and particulate matter released from the said electrostatic precipitator dust collection system;
- cooling the said flue gas stream to a lower near ambient temperature to effect condensation of water droplets that encapsulate fine particulates and fallout with said water droplets, and to accelerate oxidizing hazardous volatile organic vapors, heavy metal vapors, nitrogen oxides, and sulfur dioxide gases while recovering thermal energy to preheat a combustion air stream;
- separating the said cooled flue gas stream into a heavier gas stream enriched with carbon dioxide containing organic volatile vapors, trace heavy metal vapors, nitrogen oxides, and sulfur dioxide, and into a lighter gas stream enriched with nitrogen;
- increasing the pressure of the said heavier gas stream and then;
- cooling the said pressurized heavier gas stream to effect condensing most of the organic volatile and trace heavy metal vapors contained therein;
- separating and removing the condensate of the said hazardous vapors;
- further cooling the pressurized heavier gas stream to effect condensing most of the sulfur dioxide gas contained therein;
- separating and removing the condensate of the said sulfur dioxide gas;
- further cooling the desulfurized heavier gas fraction stream to effect condensing part of the carbon dioxide gas contained therein;
- separating the condensate of the said carbon dioxide gas;
- expanding the cleaned and cooled heavier gas fraction stream isentropically through a gas expander to produce auxiliary mechanical power and to substantially decrease the temperature of the said gas stream;
- directing the said expanded gas stream to flow into a reverse direction;
- exchanging thermal energy between the expanded reverse gas stream and the pressurized gas stream to effect cooling the pressurized gas stream wile heating and restoring the temperature of the expanded reverse gas stream;
- releasing the already cleaned and heated reverse gas stream into the atmosphere through a cooling water tower flue gas released structure;
- restoring the temperature of the said acidic water vapor condensate, liquefied sulfur dioxide, and liquefied carbon dioxide through a heat exchanger while chilling an auxiliary cooling water stream;
- continuously removing the condensate of the said hazardous vapors condensate, and liquefied gas products for further treatment, and handling.
15 more elements
Dependencies are inferred from the claim text.