Injecting and igniting device

Claim 1

A device for injecting ignited fuel into an airflow, comprising the combination of: a jacket (10) of electrically conductive material, with a generally cylindrical inner surface having its axis (XX') generally parallel to the airflow direction, a generally cylindrical shield (9) of electrically conductive material structurally and electrically united to said jacket (10), and extending coaxially with and over a substantially smaller axial extent than said jacket cylindrical inner surface, said shield being spaced internally of an upstream section only of said cylindrical inner surface and ending with a free end short of a downstream section thereof to thereby leave said downstream section unshielded and inwardly exposed, whereby said shield (9) defines with said jacket (10) both a stepped tubular duct (4, 23) and an annular duct (7) bounded by said shield and said upstream section of said inner surface, closure means (5) fitted at the upstream end of said tubular duct (4) to bottom the same, a centripetal air swirler (6) leading into said tubular duct (4) and fitted upstream of said shield (9), means (29) tapping air from said airflow to feed said centripetal air swirler (6) thereby producing an inner whirl of air (2) through said stepped tubular duct (4, 23) towards the downstream end of said jacket (10), means (8) for producing an outer whirl of air (3) around said jacket (10) towards the downstream end of said jacket (10), duct means (18, 17, 14, 11, 12) for supplying fuel to said annular duct (7), a rod (20) of electrically conductive material having a flared operative end (22) projecting into said tubular duct (4) adjacent to but inwardly spaced from said free end of said shield (9) to define therewith a first annular spark gap (24) and further with said unshielded downstream section of said jacket (10) a second annular spark gap (36) which overrides said first annular spark gap (24), means (19) for electrically insulating said electrically conductive rod (20) with respect to said electrically conductive jacket-and-shield assembly (10-9), and means (35) for applying a spark generating voltage across said first and second annular spark gaps (24, 36).

Claim 2

A device for injecting ignited fuel into an airflow, comprising the combination of: a jacket (10) of electrically conductive material, with a generally cylindrical inner surface having its axis (XX') generally parallel to the airflow direction, a generally cylindrical shield (9) of electrically conductive material structurally and electrically united to said jacket (10), and extending coaxially with and over a substantially smaller axial extent than said jacket cylindrical inner surface, said shield being spaced internally of an upstream section only of said cylindrical inner surface and ending with a free end short of a downstream section thereof to thereby leave said downstream section unshielded and inwardly exposed, whereby said shield (9) defines with said jacket (10) both a stepped tubular duct (4, 23) and an annular duct (7) bounded by said shield and said upstream section of said inner surface, closure means (5) fitted at the upstream end of said tubular duct (4) to bottom the same, a centripetal air swirler (6) leading into said tubular duct (4) and fitted upstream of said shield (9), means (29) tapping air from said airflow to feed said centripetal air swirler (6) thereby producing an inner whirl of air (2) through said stepped tubular duct (4, 23) towards the downstream end of said jacket (10), means (8) for producing an outer whirl of air (3) around said jacket (10) towards the downstream end of said jacket (10), duct means (18, 17, 14, 11, 12) for supplying fuel to said annular duct (7), a rod (20) of electrically conductive material having a flared operative end (22) projecting into said tubular duct (4) adjacent to but inwardly spaced from said free end of said shield (9) to define therewith a first annular spark gap (24) and further with said unshielded downstream section of said jacket (10) a second annular spark gap (36) which overrides said first annular spark gap (24), means (19) for electrically insulating said electrically conductive rod (20) with respect to said electrically conductive jacket-and-shield assembly (10-9), and means (35) for applying a spark generating voltage across said first and second annular spark gaps (24, 36).