Combustion equipment

• US 4,689,961 A
• Filed: 09/23/1986
• Issued: 09/01/1987
• Est. Priority Date: 02/29/1984
• Status: Expired due to Fees

• Current Assignee: Lucas Industries Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Lucas Industries Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Stratton, John F.
• Primary Examiner(s): Casaregola, Louis J.
• Assistant Examiner(s): Thorpe, Timothy S.
• Application Number:
  US06/910,783
• Time in Patent Office: 343 Days
• Field of Search: 60/734, 60/737, 60/738, 60/740, 60/746, 60/747, 60/748, 239/400, 239/403
• US Class Current: 60/748
• CPC Class Codes: F23R 3/10 for primary air F23R3/06, F23R3/045 take precedence
• CPC Class Codes: F23R 3/14 by using swirl vanes

Abstract

Combustion equipment e.g. for a gas turbine engine comprises an annular flame tube having air inlet openings fitted with respective air swirler devices surrounding respective fuel atomizers. Flare portions define an annular flare in which the atomizers and swirler devices are provided. To reduce the formation of a liquid fuel film on the wall of the flame tube, dividing means in the form of a smaller flare is provided for dividing the air flow through each of the swirler devices so as to create a fuel-free film of air adjacent the annular flare.

Claims

1. Combustion equipment comprising a flame tube having walls defining a combustion zone therein, flame tube wall means in which is defined an air inlet to be at one end of said flame tube;

an outer flare segment mounted in said flame tube adajacent said inlet, said outer flare segment having a passage through said outer flare segment communicating with said air inlet and with said combustion zone;

a fuel injector disposed in said passage and having a fuel outlet discharging into said combustion zone;

an air swirler device disposed in said passage and surrounding said fuel injector, said air swirler device including a plurality of spaced blades which are shaped and positioned to cause air flowing from said air inlet and passing through said passage and between said blades and into said combustion zone to move in a swirling motion about the flow direction axis, adjacent edges of adjacent blades defining gaps through which said air flows;

an inner flare mounted on said air swirler device, said inner flare having a downstream portion which expands radially outwardly of said passage to direct a first amount of the flowing air against an inner surface of said outer flare segment and a second amount of the flowing air along a path spaced from the inner surface of said outer flare segment;

a plurality of elongate slots defined in said outer flare segment to be located peripherally outside of said inner flare, said slots being positioned to form an annulus which is concentric with said passage and providing further communication between said air inlet and said combustion zone, each said slot being locating adjacent to one of said gaps, each slot having a radially outer end and a radially inner end with a longitudinal axis extending between said ends, said slots being oriented so that said longitudinal axis is located along a secant of said annulus and is inclined so that the direction of extent of said slot longitudinal axis from said outer slot end to said inner slot end is opposite to the direction of said air swirling motion, means for providing air to said slots so that air passing through said slots flows in a direction different from said swirling direction and flows on a path which surrounds said swirling air to constrain and confine flow of fuel from said fuel injector and swirling air from said air swirler device and prevent such fuel and swirling air from moving radially outward beyond said annulus.

2. Combustion equipment as claimed in claim 1, wherein said flame tube wall has a plurality of slots located in a second annulus, each of said flame tube wall slots being aligned in the direction of flow into said outer flare segment passage with a respective one of said slots in said outer flare segment but having a smaller area.

3. Combustion equipment as claimed in claim 2, wherein said flame tube wall has a plurality of small apertures therethrough which are not aligned in the direction of flow into said outer flare segment passage with slots in said outer flare segment.

4. Combustion equipment as claimed in claim 1, wherein an upstream end of said inner flare is mounted on said air swirler blades.

5. Combustion equipment as claimed in claim 4, wherein a recess is provided in a downstream end of each swirler blade, and said inner flare is mounted in said recesses.

6. Combustion equipment as claimed in claim 1, wherein said inner flare is positioned relative to said injector to be spaced from the inner surface of said outer flare segment to define a gap sized so that the first amount of air represents 3 to 5 of the total flow through said flame tube.