Power company finds cool solution to hot problem
Swing-type isolation valves leaked hot furnace gases into Dayton Power & Light's coal pulverizers, so the power company switched to tighter knife gate valves.
Dayton Power & Light, Stuart Station, pulverizes and burns coal to generate 2,400 megawatts of electricity. Each of the power company's four units has six coal pulverizers and a furnace. Every hour, each pulverizer reduces 40 to 60 tons of 3/4- to 1 1/2-inch-diameter coal to a very fine powder. Eight 16-inch-diameter coal pipes run from the top of each pulverizer to the furnace. At a point before the furnace, each coal pipe has a coal nozzle impeller that blows the pulverized coal into the furnace, where the coal burns at about 1,000ºF.