METHOD AND APPARATUS FOR BURNING PULVERIZED FUEL

摘要

A method and an apparatus for combusting pulverized fuels in a tangentially fired boiler and reducing emission of nitrogen oxides comprises the steps of feeding a substantially air-deficient mixture of fuel and primary air through a fuel feeding pipe (1) tangentially into a furnace of the boiler in order to form a reducing flame (II) and blowing at least one stream of combustion air into the furnace. The invention is based on that the stream of primary air and fuel is caused to recirculate and turbulate at the open end (2) of the fuel feeding pipe by passing it through a flame holder (9) extending into the fuel feeding pipe (1), and on that the stream of combustion air is directed away from the primary air/fuel stream in order to prevent the combustion air from mixing with the reducing flame (II).