Abstract: A method and reactor for processing fuels with a wide particle size distribution, particularly for flame combustion. The fuel is blown tangentially with the aid of an airflow into a swirl chamber containing a burning mass, thus creating a vortex, from the center of which a flow of material is led out of the swirl chamber. The vortex created by the feed of the fuel-air mixture and the diameter of the outlet flow are arranged to create a selective delay for coarse particles, so that the size of the particles is reduced, through mechanical treatment caused by evaporation, pyrolysis, and collision, to become smaller than the desired limit value, before they escape from the swirl chamber. The temperature of the cylindrical jacket of the swirl chamber is held below the melting point of the ash.

Abstract: An arrangement for converting a conventional oil boiler to a boiler with moist, granular and solid fuel, utilizes a fuel combustion gas dryer connected to the combustion gas line of the boiler, and a solid fuel combustion device to replace the oil burner. The combustion gas dryer is a so-called circulating fluidized bed (CFB) dryer together with a particle separator and a combustion gas center tap has been fitted into the oil boiler, through which center tap hot combustion gas has been set to be mixed with combustion gases of the normal outlet in the desired proportion in order to regulate the temperature of the drying gas of the dryer. The combustion devices may include a cyclone burner.