Abstract: A thermal reductor system is provided with a rotary ignition chamber having an input end, a discharge end of enlarged size relative to the input end and an inside chamber wall having a configuration for promoting natural flow of gases, smoke and ash discharge from the input end to the discharge end. To limit discharge of solid residue to a maximum predetermined size, the discharge end of the chamber is provided with a restricted ash exit. So that the ignition chamber is particularly suited for disposing of liquid wastes in a compact chamber construction, the inside chamber wall has a restriction intermediate the input and discharge ends of the chamber defining a barrier to liquid flow. An exhaust duct is provided for the passage of gases and smoke from the ignition chamber.