Pulverized coal injection nozzle

摘要

A nozzle for the injection of solid fuel in dust form into a combustion chamber, to be installed in correspondence with the outlet of a burner coaxially to the longitudinal axis of the burner, comprising a stationary annular part divided into coal ducts of a circumferential width that decreases towards outlet section to form coal-dust-rich air streams, a central duct for a coal-dust-poor air stream sideways delimited by the coal ducts and having an outlet end, a central member that is axially mobile within the central duct, for varying the cross section of a central passage delimited by the stationary annular part at the outlet end. Air ducts for the coal-dust-poor air stream are formed between each pair of adjacent coal ducts in the stationary annular part communicating with the central duct and having a circumferential width increasing toward the outlet end. Deflectors for the coal-dust-poor stream are provided at the outlet from the ducts to direct the stream from each air duct in a direction diverging radially from the central duct.