NOVELTY - The operation of a furnace for the combustion of sludge in a fluidized bed comprises pressing the sludge into material strands by a planetary gear extruder, and granulating and combusting the sludge. The extruder stands in effect connection with combustion in such a way that the grain size of granulation is regulated as a function of the combustion and/or the heat value of the sludge is regulated as a function of the combustion by mixing of fuels with higher or low heat value in extrusion and/or aggregates are mixed in extrusion for the combustion and/or for extruder.    USE - Used for the operation of furnace for the combustion of sludge in a fluidized bed.    ADVANTAGE - The process avoids nitrogen oxide pollution by reducing the combustion temperature and/or by the injecting urea in the flue gas. The fluidized bed plant for operation of furnace for combustion of sludge can be managed very easily.    DETAILED DESCRIPTION - The operation of a furnace for combustion of sludge in a fluidized bed, comprises pressing the sludge into material strands by planetary gear-extruder, and granulating and combusting the sludge. The extruder stands in effect connection with combustion in such a way that the grain size of granulation is regulated as a function of the combustion and/or the heat value of the sludge is regulated as a function of the combustion by mixing of fuels with higher or low heat value in extrusion and/or aggregates are mixed in extrusion for the combustion and/or for extruder. A plant is used with smaller spacing of the extruder from the fluidized bed. The granulation speed is changed for the grain size regulation. A belt conveyor is used for the transport of the sludge particles into the combustion or through an extrusion, which distributes the sludge particles directly into the combustion. Different hoppers for sludge and different aggregates are attached to target material for extrusion. A dosage is used for sludge and aggregate and a screw-conveyor is used for carrying together the sludge and the additional aggregate. A filling screw is used, which receives a feedstock by screw-conveyor and presses the feedstock into extrusion. In this method the mixing of fuel and/or combustible municipal waste and/or combustible commercial waste takes place into the extrusion. The method takes place through the mixing of agents for the nitrogen oxide reduction in the combustion and/or for the desulfurization of the combustion gases. The method takes place through the addition of lubricating oil and/or the addition of surfactant (3 wt.%), related to the feedstock in the extrusion and/or by the addition of conditioning agents for the sludge.    DESCRIPTION OF DRAWING(S) - The drawing shows a vertical arrangement of planetary gear-extruder:    Feeding hopper; (2)    Central spindle. (3)