Flue for a domestic gas boiler comprising a condensate collector to reduce vapour pluming

摘要

A flue 1 offering reduced pluming is provided, the flue comprising a flue pipe 2 for carrying flue gas and a liquid collector adapted to collect condensation from the interior of the flue pipe and to shield it from the flue gas. The flue pipe has an inlet 4 for receiving combustion products from the boiler and an outlet 6 for exhausting the combustion products to the atmosphere. The flue may be installed in association with a balanced flue boiler such that the flue pipe is arranged concentrically within an air inlet pipe 8 so as to define a passage 10 through which fresh air can be admitted. The liquid collector is formed by an interior baffle 12 which extends along a lowermost region of the flue pipe so as to partition the flue pipe into a gas carrying region 14 and a liquid collection region 16 shielded from the flue gas flow by the baffle. The interior baffle extends towards the flue inlet and seals with the wall of the flue pipe to form a reservoir region 26. The gas pressure from the combustion region is sufficient to maintain the collected liquid within the reservoir whilst the boiler is operating but as soon as the combustion process stops the collected liquid is able to drain through aperture 28 into the boiler from where it is collected by a boiler drain. The liquid collection properties of the flue pipe may be enhanced by coating the interior of the pipe with a non-wetting material such as PTFE and by utilising flow director means in the form of fins 20 to impart rotational motion to the flue gas. A helically extending groove 24 may also be formed in the flue pipe to catch any moisture droplets being blown longitudinally along the wall of the flue pipe by the flue gas flow.