Abstract: The invention relates to heat engineering and can be used for designing and reconstructing furnaces for industrial boilers. More advantageously the inventive furnace can be used for burning coarsely dispersed broken combustibles, coal and schist. The invective swirling-type furnace operating method consists in returning the controllable amount of a coal-ash mixture from an ash catcher located behind a combustion to the internal surface thereof. Said swirling-type furnace comprises a combustion chamber provided with a sloping bottom which is formed by slops of lower parts of the walls thereof, a bottom-blowing device arranged under the sloping bottom mouth and an inclined burner which is used for supplying a fuel-air mixture and is fixed to the combustion chamber wall. The furnace is provided with the ash catcher located behind the combustion chamber and a recirculation ash channel, whose one end communicates with the ash catcher and the other with the combustion chamber internal space.

Abstract: A furnace consists of at least one wall-mounted burner tilted downward for feeding air-fuel mixture and of a prism-shaped ash hopper. Slopes of the walls of lower combustion chamber region define the slotted mouth of ash hopper. The bottom airflow device is located below the ash hopper mouth the wall opposite to the airflow nozzle of the bottom airflow device has a concave form. In accordance with said invention the bottom airflow device spans along the entire width of the ash hopper mouth. The concave wall in its upper region meets the ash hopper mouth and an imaginary plane being a continuation of said concave wall crosses the opposite slopes of the wall of ash hopper in its middle region. The axis of bottom airflow nozzle passes along the lower region of said concave wall and is directed to form a 0-to-45 degree angle between said axis and lower region of said concave wall. The concave wall may be tilted relative to horizon at the angle of 20-45 degrees.