Patent AU-2017258832-B2 (AU)
Title: Fuel/air mixture and combustion apparatus
Inventor: AKBARIMONFARED AMIN
IPC: F24H3/00
Filed: 2017-11-07
Granted: 2019-06-13
Abstract: FUEL/AIR MIXTURE AND COMBUSTION APPARATUS A fuel-fired heating apparatus comprising a combustion system (10), a fan (72), and a gaseous fuel injector (52). The combustion system (10) comprises: a fuel-air mixing structure (14, 16) that includes: an outer housing (22a) that defines an interior cavity and comprises a first inlet end (24) and a first outlet end (26), the first inlet end (24) comprising a central opening (28) and a plurality of vane structures (32) radially extending and circumferentially spaced from the central opening (28); an inner housing (22b) that includes a second open inlet end (34) and a second open outlet end (36); and a venturi structure (38) disposed in and laterally circumscribed by the inner housing (22b). The venturi structure (38) circumscribes an axis (46) extending between the second open inlet end (34) and the second open outlet end (36) of the inner housing (22b). The venturi structure (38) comprises: (a) a venturi inlet (40) adjacent the second open inlet end (34) of the inner housing (22b), (b) a venturi outlet (42) adjacent the second open outlet end (36) of the inner housing (22b), and (c) a side wall extending from the venturi inlet (40) to the venturi outlet (42) such that the side wall tapers from the venturi inlet (40) and the venturi outlet (42) towards a substantially mid-portion of the venturi structure (38). The side wall of the venturi structure (38) comprises a plurality of perforations (44) that are circumferentially disposed around the side wall from adjacent the venturi inlet (40) to the substantially mid-portion of venturi structure (38). The inner housing (22b) is disposed inside the interior cavity defined by the outer housing (22a) such that: (a) the first inlet end (24) of the outer housing (22a), the second open inlet end (34) of the inner housing (22b), and the venturi inlet (40) of the venturi structure (38) are substantially axially aligned to define an open inlet end (56) of the fuel-air mixing structure (14, 16), and (b) the first outlet end (26) of the outer housing (22a), the second open outlet end (36) of the inner housing (22b), and the venturi outlet (42) of the venturi structure (38) are substantially axially aligned to define an open outlet end (48) of the fuel-air mixing structure (14, 16). The fan (72) flows combustion air through the venturi structure (38) from the venturi inlet (40) to the venturi outlet (42), wherein a plurality of vane structures (32) associated with the first inlet end (24) of the outer housing (22a) is operative to impart to combustion air entering the venturi inlet (40) by operation of the fan (72) a swirling flow pattern centered about the axis (46). The gaseous fuel injector (52) is disposed at the open inlet end (56) of the fuel-air mixing structure (14, 16) through the central opening (28) of the outer housing (22a) to radially inject gaseous fuel from a source thereof into the combustion air traversing an interior of the venturi structure (38) in the swirling flow pattern to induce a cross-flow and form with the combustion air a fuel-air mixture dischargeable through the venturi outlet (42). The inner housing (22b) defines therein a chamber that laterally extends around the venturi structure (38) and is in fluid communication with the interior of the venturi structure (38) via the plurality of perforations (44) on the side wall of the venturi structure (38). The chamber receives and is filled with at least a portion of the fuel-air mixture that enters the chamber from the interior of the venturi structure (38) through the plurality of perforations (44) on the side wall of the venturi structure (38) to create a fluid damping volume in the chamber.