Economiser for central heating system - has heat exchanger condensing moisture in flue gases to preheat boiler return

摘要

The economiser has a steel casing (6) with a corrosion resistant inner surface. It has an entry (7) and outlet (8) for flue gases at high level separated by a vertical partition (9) to compel the gases to follow a U-shaped path. A bundle of U-tubes dips into the casing with one arm of each U on each side of the partition (9). One set of arms is connected into an inlet header (2) and the other set into an outlet header (4). The headers are connected in the boiler water return. Heat is transferred to the water by condensation of the moisture in the flue gases.