Tri-sector regenerative oxidant preheater for oxy-fired pulverized coal combustion

A method for preheating primary and secondary oxidant in a tri-sector rotary regenerative oxidant preheater including a stationary housing, a rotor rotatably mounted in the housing, sector plates located at the axial ends of the rotor dividing the preheater into a flue gas sector, a secondary oxidant sector, and two primary oxidant sectors, the secondary oxidant sector being interposed between the primary oxidant sectors, the method comprising:

• passing primary oxidant to be heated through the primary oxidant sectors;
• passing secondary oxidant to be heated through the secondary oxidant sector;
• passing hot flue gas through the flue gas sector to heat the primary and secondary oxidants;
• and
• maintaining the environment in both primary oxidant sectors at about the same negative pressure as that of the flue gas sector.

An oxy-fired pulverized coal combustion power plant arrangement, including:

• a boiler;
• a boundary wall forming a combustion space within the boiler;
• a burner port formed in the boundary wall;
• a burner wall spaced from the boundary wall to form a windbox therebetween;
• a coal burner nozzle extending through the port and facing the combustion space;
• a coal pulverizer;
• conduit means for supplying coal to the pulverizer to be pulverized therein;
• a tri-sector rotary regenerative oxidant preheater;
• sector plates for dividing the preheater into a flue gas sector, two primary oxidant sectors, and a secondary oxidant sector interposed between the primary oxidant sectors;
• duct means for delivering hot flue gases from the boiler to the preheater;
• a forced draft fan for supplying secondary oxidant to the preheater to be heated through the secondary oxidant sector;
• duct means for conveying the heated secondary oxidant to the windbox;
• a primary oxidant fan for drawing primary oxidant through the preheater to be heated through the primary oxidant sectors;
• duct means for conveying the heated primary oxidant to the pulverizer;
• and
• conduit means for conveying pulverized coal and the heated primary oxidant to the coal burner nozzle for mixing with the secondary oxidant and establishing a stable flame in said combustion space.