Abstract: Disclosed is a combustion device and method for combusting granular, solid fuel, for example wood pellets. The combustion device includes a chamber having an outer wall and an inner wall, which inner wall divides the chamber into a combustion air space and a combustion chamber. Further, the combustion device includes at least one blast apparatus for providing primary combustion air and secondary combustion air and a rotating unit for rotating the combustion chamber. The inner surface of the combustion chamber includes a number of steps for lifting combustion fuel in the combustion chamber, when the combustion chamber is rotated. Further, primary combustion air is provided into the combustion chamber for contributing combustion of combustion fuel and for moving combustion fuel on the steps. In addition, secondary combustion air is provided into the combustion chamber for removing completely combusted fuel and/or combustion gases from the combustion chamber.

Abstract: A device for combustion of moist fuel includes a combustion chamber with a moving fire grate disposed at a bottom portion thereof and a drum dryer located within the combustion chamber above the fire grate. The dryer drum rotates and includes therein an involuted drum in communication with a feeding apparatus external to the combustion chamber. The feeding apparatus transports fuel from a bin to the involuted drum. As the drum dryer rotates the fuel therein moves toward an end thereof and is dried by the heat of the combustion chamber. From an end of the drum dryer, the dried fuel falls onto the fire grate and is burned.