The refuse moves through the combustion chamber, on a series of reciprocating grate stokers. There are three zones to provide efficient burning. The first zone, dries and ignites the waste, the second is where most of the combustion occurs and the third zone assures that the refuse is completely burned before the “bottom ash” is moved to the ash removal system below the furnace. Approximately 4 tons of refuse can be fed into each of the smaller units each hour (or 100 tons per day per unit) and approximately 8 tons per hour can be fed into the 200-ton per day unit.
With computer-controlled combustion, and a temperature of 1,800 degrees F., the process is efficient. Conditions in the furnaces are continually monitored. Steam pressure is stable and flow is a factor of demand. Combustion efficiency remains at a maximum, controlling pollutants such as carbon monoxide, acid gases, heavy metals, dioxins and particulate matter well below regulatory limits. A continuous emissions monitoring system constantly measures stack gas composition ensuring that the process runs properly, and that all permit conditions are in compliance.