| 摘要 |
Draught in a flue (12) leading from a heat source (32) is increased by injecting a flow of gas (22) into the flue in a direction to create suction at the heat source. The flow of gas, generally air, may be generated by blower means such as an electrically powered fan (18) which is located externally of the flue so as not to inhibit cleaning of the flue or obstruct normal gas flow in the flue. Gas is directed from the blower means to the interior of the flue via duct means. In a preferred embodiment for use with existing flues the duct means comprises a probe-like tube (40) adapted to be passed down inside a flue outlet and from which gas is expelled within the flue from an outlet (56) in the tube. |
