Flue (?), n. [Cf. OF. flue a flowing, fr. fluer to flow, fr. L. fluere (cf. Fluent); a perh. a corruption of E. flute.]
An inclosed passage way for establishing and directing a current of air, gases, etc.; an air passage; esp.:
(a)
A compartment or division of a chimney for conveying flame and smoke to the outer air.
(b)
A passage way for conducting a current of fresh, foul, or heated air from one place to another.
(c) (Steam Boiler)
A pipe or passage for conveying flame and hot gases through surrounding water in a boiler; -- distinguished from a tube which holds water and is surrounded by fire. Small flues are called fire tubes or simply tubes.
Flue boiler. See under Boiler. - - Flue bridge, the separating low wall between the flues and the laboratory of a reverberatory furnace. --
Flue plate (Steam Boiler), a plate to which the ends of the flues are fastened; -- called also flue sheet, tube sheet, and tube plate. --
Flue surface (Steam Boiler), the aggregate surface of flues exposed to flame or the hot gases.
© Webster 1913
Flue (?), n. [Cf. F. flou light, tender, G. flau weak, W. llwch dust. √84.]
Light down, such as rises from cotton, fur, etc.; very fine lint or hair. Dickens.
© Webster 1913
Flue, n.
In an organ flue pipe, the opening between the lower lip and the languet.
© Webster 1913