Abstract

A system for pyrolysis and combustion of combustible solid material, such as waste, which comprises a pyrolysis chamber having a series of spaced vertically disposed movable grates, forming a plurality of stages in the pyrolysis chamber and permitting downward movement of solid feed material at a controlled rate countercurrent to the upward flow of hot gaseous products, the movable grates being synchronized for successive actuation whereby the charge of feed material is successively passed through each of the stages to the bottom of the pyrolysis chamber. Inlet lines are provided for introducing air into each of such stages and into the bottom of the pyrolysis chamber. A feed-lock apparatus is provided for feeding combustible solid feed material into the upper section of the pyrolysis chamber; the feed-lock apparatus includes a hopper for receiving particulate feed material and a ram for compressing the particulate feed material into a compacted block which temporarily functions as a gas seal from the pyrolysis chamber, and for introducing the compacted block into the upper section of the pyrolysis chamber. An exit conduit is also provided for removing overhead fuel gas from the pyrolysis chamber, and an ejector is provided for introducing the overhead fuel gas from the exit conduit into a combustion chamber, and for passage of the combustion gases to a heat load. A diverter valve and throttle valve are provided in the exit conduit for selectively diverting overhead fuel gas or for throttling the process, when desired, e.g., for safety reasons. A water-filled discharge conveyor is provided for quenching the ash and other non-combustible material and carbon in the bottom of the pyrolysis chamber, and removing the resulting slurry therefrom.