DEVELOPMENT OF ASH MELTING FURNACE AND RECYCLING SYSTEM FOR WET SEWAGE SLUDGE USING OXYGEN ENRICHMENT

摘要

To decrease the volume of sewage sludge and convert it to the resources, a unique compact sludge-melting furnace was developed. The wet sludge was fed directly in the furnace by snake pump and oxygen enriched air was provided by a PSA unit. The sludge was melted at a temperature of approx.1300 to 1500℃. The melted slag discharged from the bottom of the furnace and was crystallized on a crystallizing conveyer. Produced slag was effectively usable as high-quality aggregate including base course materials and asphalt mixtures. Incinerated exhaust gas was discharged from the top of the furnace, and was cooled down after secondary combustor. Due to achieving a mild combustion, the amount of generating of particulates and NO_X present in the exhaust gas decreased. In addition, the dioxin concentration was much lower than that of emission standard in Japan.