Pulverised fuel fired steam generating plant - is operated by recycling some cleaned flue gas to pulverisers, partially via air preheater

摘要

The operational process is intended for a steam generating plant fired with pulverised fuel with primary and secondary air preheaters, electrostatic filters, induced-draught blower and chimney. The system is sequentially arranged in the flue gas duct. It involves recycling flue gas from downstream of the blower (5) through a recirculating blower (8) to the pulverisers, either directly or via the primary air section (2a) of the preheater. Dampers (10,14) in the branches (13a,9a) to the individual pulverisers control the gas flow. Instead of a common recirculating blower, individual pressure boosting blowers may be fitted in the combined line to each pulveriser.