Heat exchanger for boiler exhaust gases - extracts remaining heat from central heating fuel exhaust before discharging to atmosphere

摘要

This heat exchanger can be used in oil or gas central heating systems to save a considerable proportion of the energy normally wasted in the form of the hot exhaust gases which flow out of the flue. The exchanger, which is inserted between the boiler and the flue, has a fan which blows the hot gases across a maze of tubes. The heating medium, usually water, flows through the exchanger after returning from the radiators, thus pre-heating the water before it re-enters the main boiler. A flue 'damper', controlled by a magnetic switch and a mechanical linkage ensures that the gases remain in the exchanger long enough to release most of their heat to the return water, while ensuring that the flow of gases is sufficient to prevent a potentially dangerous build-up of poisonous gases.