Abstract: A device for gasifying biomass sludge having particle size less than 1 cm, and 20% to 100% solids content has a primary chamber, a fume transfer vent, a mixing chamber which accepts fumes from the primary chamber, and an afterburner chamber in fluid communication with the mixing chamber. A secondary burner produces an initial heating flame within a vertical portion of the afterburner chamber. A heat transfer chamber is in fluid communication with the afterburner chamber. Heated gases from the afterburner chamber cause heating of the heat transfer chamber. The primary chamber has a heat conductive floor superimposed over the heat transfer chamber so that conductive and convective heating of the primary chamber occur. At least one primary auger is located crosswise in the primary chamber between a sludge feed hopper and an ash hopper. The heat transfer chamber underlies the primary auger near the end at the ash hopper.

Abstract: The cremator disclosed is of the kind in which reduction burning takes place in a coffin chamber, followed by oxidation burning in an afterburner chamber. It is also of the kind in which partly cremated embers can be moved to an ember-reducing location to make room for another coffin to be admitted to the coffin chamber. The disclosure shows the ash removal port in the side of the cremator, which allows the afterburner chamber to occupy space behind and underneath the coffin chamber; an arrangement which makes for a very compact, fuel efficient, easy-to-construct unit. The hearth includes an ash-trough for ember reduction. The hearth can be thin because it is supported on the central wall that divides the ducts of the afterburner chamber, which makes for good heat transfer, and quick warm-up.