Fire-Tube Boilers Single-Flue Boiler Horizontal Single Fire Tube Externally-Fired

FIRE-TUBE BOILERS SINGLE-FLUE BOILER: HORIZONTAL, SINGLE FIRE TUBE, EXTERNALLY-FIRED In the Cornish, Lancashire, and Galloway boiler the large internal flue served as a fire box. There was, however, a flue boiler having the fire external to the shell. The boiler shown in Fig. 10 resembles the plain cylindrical boiler both in appearance and setting, but it has one or more large flues extending from end to end. This flue increases the heating surface to such an extent that the boiler can be considerably shorter than the plain cylindrical.