Abstract: A burner for the combustion of coal dust in which a stream of primary air and coal dust mixture is conducted through a dust conduit connected to a primary dust tube. A secondary air tube surrounds the primary dust tube, and a tertiary air tube surrounds the secondary air tube. The secondary and tertiary air tubes are connected to a helically-shaped input housing, and a conically flared section extends from each of the secondary and tertiary air tubes. An angular momentum is applied in the dust conduit divides the primary air and coal dust mixture into high-dust and low-dust partial streams, so that the high-dust partial stream flows through the primary dust tube, and the low-dust partial stream flows through the primary gas tube.
Abstract: The process for combustion of coal dust with combustion air in burners and for reducing the production of NO.sub.x during the combustion. Combustion air is fed to the burners in form of primary air and secondary air. The burners are supplied coal dust through the primary air in a mixture of coal dust and primary air. A primary gas is generated with combustible gaseous components from the mixture of coal dust and primary air, through pyrolysis of the coal dust in the ignition region of the burners. In the ignition region, there is lowered the mean ratio of oxygen components in the primary gas to the oxygen amount required to burn freely released combustible gaseous components of the primary gas by reducing the oxygen component in the primary gas and/or injecting the primary gas with a combustible external gas.
Abstract: A burner for burning powdered fuel in air. The air is divided into concentric annular currents. A tube (6) conveys primary air or gas. The tube is surrounded by another tube (12). The second tube conveys secondary air. The exit of the primary-air tube inside the secondary-air tube is surrounded by an annular baffle (26). The baffle is open at each end, has secondary air flowing through it, and extends axially beyond the primary-air tube as much as 25% of the tube's outside diameter. The thickness of the gap (25) between the primary-air tube and the baffle is at least 1.5% of that diameter.