Contents Notes |
"The results of three years of research on the utilization of shredded and magnetically separated municipal refuse to supplement high-sulfur coal as fuel in a stoker-fired boiler are presented. The facilities of the Columbus, Ohio, Municipal Electric Plant were used for this program. During the first half of the research, a refuse handling and furnace feed system consisting of agriculture crop handling equipment was used. With this equipment, the feasibility of blowing shredded refuse into a boiler and burning it completely on a traveling grate was demonstrated. Corrosion probe exposures were used to show the effectiveness of cofiring to reduce short-term corrosion of boiler tube metals. Reduced emissions of sulfur dioxide (SO2} from the high-sulfur coal also resulted from dilution of the coal with refuse and by action of alkaline components of the refuse. To study the handling and combustion of larger amounts of shredded refuse and to measure long-term corrosion effects, an improved system was developed and installed during the second half of the program. This system consisted of a hydraulic push-pit, augers, and a belt to convey the refuse to air-swept spouts that injected the refuse into the boiler. Amounts of refuse up to 6800 kg/hr (7.5 tons per hour) were burned successfully using this system. It was demonstrated that 700-hour corrosion rates with an average of 22 weight percent refuse and high-sulfur coal were 5 to 10 times less than those with bulk refuse burning and about equal to those from coal alone. Sulfur dioxide emissions were reduced as a function of the refuse content of the mixture. The cofiring with refuse had no significant effect on particulate loading of the flue gases, fly ash resistivity, or grate ash composition, but the ash fusion temperature was lowered somewhat." |