Abstract: An integrated sorbent injection, heat recovery, and flue gas desulfurization system is disclosed. A dry sorbent is injected into the flue gas upstream of the air heater. This reduces the acid dew point temperature, permitting additional heat energy to be captured when the flue gas passes through the air heater. The flue gas then passes through a desulfurization unit and through a baghouse, where solids are captured. The capture of additional heat energy permits the overall boiler efficiency to be increased while safely operating at a lower flue gas temperature. The integrated system consumes no greater quantity of sorbent than conventional methods but provides the benefit of improved plant heat rate.

Abstract: A method and apparatus effectively bypasses flue gas through or around selected boiler convection heat transfer tube banks within a new or existing boiler flue. Heat transfer tubes are removed, or omitted in the design of a new boiler flue, forming one or more voids at one or more locations within the tube banks. A bypass flue or conduit is formed within each void, for example using steel plates, along with existing flue walls, or using an integral sleeve. A wall of the bypass flue may include water or steam-cooled tubes. Dampers may be installed at either end of or within the bypass flue to control the amount of flue gas directed through each bypass flue.

Abstract: A method and apparatus effectively bypasses flue gas through or around selected boiler convection heat transfer tube banks within a new or existing boiler flue. Heat transfer tubes are removed, or omitted in the design of a new boiler flue, forming one or more voids at one or more locations within the tube banks. A bypass flue or conduit is formed within each void, for example using steel plates, along with existing flue walls, or using an integral sleeve. A wall of the bypass flue may include water or steam-cooled tubes. Dampers may be installed at either end of or within the bypass flue to control the amount of flue gas directed through each bypass flue.