Stepped Hearth incinerators have multiple hearths in cascading steps. Waste is loaded by a ram feeder and begins combustion on the first level. As new waste is loaded on the first level, it pushes partially burned waste to the next lower step or level. A tumbling action results, exposing more surface to the combustion chamber and ensuring more complete destruction of the waste.
Each successive charge moves waste to the next lower level. Automatic de-ashing systems can be used to remove the ash without needing the system to cool, so true continuous operation can be achieved.