Air preheater for boiler burner - has heater for flue gas duct and hot air supply passage, opening in burner air supply passage

摘要

The air preheater for boiler burners, e.g. for domestic heating etc. is for system with a blower. It comprises a closed annular casing (2) around the flue duct (3), with inlet openings (13) in one outer face and opposite these a duct (20) opening into the cold air duct (21) to the blower (40). An uptake temp. sensor (23) controls dampers (31,22) in the upheated and heated duct sections respectively working in opposition. Radial fins from flue duct to casing inside wall connect, and conduct heat between the flue duct and casing. The heat transfer to the air is improved by ribs on fins inside the latter.