GB137605A - Improvements in means for heating the air supplies to furnace fronts of steam boilerfurnaces and the like - Google Patents

Abstract

137,605. Smith, L. E., and Zulver, C. Jan. 21, 1919. Furnace fronts.-In steam-boiler furnaces :adapted for oil or coal firing, such as that described in Specification 106,703, air for combustion is heated in a chamber surrounding the firing-opening, and ribs are provided on the inner walls of the chamber to heat, guide, and distribute the air on its way to the air-admission ports leading into the firing-opening. As shown in Figs. 1 and 2, air is admitted to the hollow front 3 through a door 2 and is guided by ribs 4, 5 to an opening 6 in the dead-plate 7, through which it passes into the upper part of the hollow front and is then guided and distributed by ribs 9, 10 to the ports 8, 11 in the sides of the firing-opening. The openings 8, 11 may be fitted with dampers adapted to be operated separately or simultaneously. The opening 8 may be smaller than the opening 11 to obtain equal distribution of the air. An additional air-admission door 12 may be provided in the upper part of the hollow front. According to a modification, a division wall is provided across the upper part of the air chamber to ensure that all the air from beneath the deadplate passes to the port 8. A separate door-controlled inlet is provided to admit air to the upper part of the chamber for supplying the port 11. Fig. 6 shows a further modification in which the main air supply is admitted through a door 2 and is distributed equally to the ports 8, 11 by providing the hollow front with vertical ribs 16, 17. An auxiliary door 12 is provided as described above, and the doors 2, 12 may be arranged as double doors, so that the air supply may be controlled to each side of the furnace. Guide or deflecting ribs 18, 19 and heat-radiating ribs 20 are provided. Figs. 7 and 8 show a modification in which tubular air-admission doors are provided, as described in the above-mentioned Specification, below the level of the fire-bars to admit air to the hollow front, which is provided with a deflecting-plate 22. The air passes through aperture.s 23 in the dead-plate to the firing-opening. Air is admitted to the upper part 25 of the hollow front through a door 24. Heat-radiating ribs 27 and deflecting-ribs 28 are provided on the inner wall, and air-admission ports 8, 11 are provided as described above. A deflecting-rib 32 serves to guide the air to the oil spray. Figs. 11 and 12 show a further modification in which the casing enclosing the burner is enclosed by an airheating chamber 33 provided with guiding-ribs 34, 35.