Retrofit injection of humid gas from sludge dryer and secondary air in WTE furnaces of Québec city

This paper discusses the retrofit injection of humid gas from sludge dryer with secondary air in the WTE furnaces in Québec City. In 1992, a municipal sludge treatment plant was added in the WTE building. Three sludge dryers, each connected to a furnace, were added. Direct contact with hot furnace gas was used to dry sludge in a rotary drum. Humid gas from the dryer was returned to the rear wall of the furnace just above the finishing grate.