Premixing burner

• US 5,573,395 A
• Filed: 02/03/1995
• Issued: 11/12/1996
• Est. Priority Date: 04/02/1994
• Status: Expired due to Fees

• Current Assignee: Alstom SA
• Original Assignee: ABB Management AG (ABB Limited)
• Inventors: Althaus, Rolf, Chyou, Yau-Pin
• Primary Examiner(s): Dority, Carroll B.
• Application Number:
  US08/383,580
• Time in Patent Office: 648 Days
• Field of Search: 431/283, 431/284, 431/285, 431/278, 431/174, 431/175
• US Class Current: 431/278
• CPC Class Codes: F05B 2240/122 Vortex generators, turbulators, or the like, for mixing by creating turbulence F05B2260/222
• CPC Class Codes: F23C 2900/07002 Premix burners with air inlet slots obtained between offset curved wall surfaces, e.g. double cone burners
• CPC Class Codes: F23D 11/402 Mixing chambers downstream of the nozzle
• CPC Class Codes: F23D 14/22 with separate air and gas feed ducts, e.g. with ducts running parallel or crossing each other
• CPC Class Codes: F23D 23/00 Assemblies of two or more burners gas burners with provision for a retention flame F23D14/26

Abstract

A premixing burner comprises a pilot burner (101) operating on the double-cone principle and a plurality of main burners arranged around the pilot burner. A gaseous and/or liquid fuel is injected into the main burner (52), which has a circular duct (20), as a secondary flow into a gaseous main flow. The main flow is first of all guided over vortex generators (9), a plurality of which are arranged next to one another around the circumference of the duct (20) through which flow takes place.

Claims

1. A premixing burner, comprising:

a centrally arranged pilot burner having a mixing space with an outlet and means for introducing air and fuel into the mixing space for mixing before exiting through the outlet;

a plurality of main burners each having a duct for guiding a gaseous main flow of air, the main burners being arranged around the pilot burner;

means for injecting at least one of a gaseous and liquid fuel into the duct of each of the main burners as a secondary flow into the gaseous main flow for mixing the fuel and main flow in the duct; and

,

a plurality of vortex generators mounted in the duct of each of the main burners upstream of an outlet of the main burner, the vortex generators arranged next to one another around a circumference of the duct, each vortex generator comprising a body projecting into the main burner duct and having a shape for creating vortices with an axis substantially parallel to a flow axis of the main burner.

2. The premixing burner as claimed in claim 1, wherein the pilot burner comprises two hollow conical partial bodies positioned to define a conical space aligned in the direction of flow, the partial bodies being positioned with respective center lines offset relative to one another so that adjacent walls of the two partial bodies form along their length longitudinal ducts for a tangentially directed flow of combustion air into the conical space and longitudinally distributed gas inlet openings provided in the walls of the two partial bodies in the region of the longitudinal ducts.

3. The premixing burner as claimed in claim 1,

wherein each vortex generator has three surfaces around which flow can take place freely, which surfaces extend in the direction of flow, a first surface forming a top surface and a second and third surface forming side surfaces,

wherein the side surfaces abut a same wall segment of the duct and meet at an acute angle to form a V-shape,

wherein the top surface is oriented at an angle to the duct wall and an edge of the top surface contacts the duct wall extending transversely to the flow direction at the same wall segment as the side walls,

and wherein longitudinally directed edges of the top surface abut longitudinally directed side surface edges protruding into the flow duct.

4. A premixing burner, comprising:

a centrally arranged pilot burner, comprising two hollow conical partial bodies positioned to define a conical space aligned in the direction of flow, the partial bodies being positioned with respective center lines offset relative to one another so that adjacent walls of the two partial bodies form along their length longitudinal ducts for a tangentially directed flow of combustion air into the conical space and longitudinally distributed gas inlet openings provided in the walls of the two partial bodies in the region of the longitudinal ducts;

a plurality of main burners each having a duct arranged around the pilot burner;

means for injecting at least one of a gaseous and liquid fuel into the duct of each of the main burners as a secondary flow into a gaseous main flow; and

,

a plurality of vortex generators mounted in the duct of each of the main burners upstream of an outlet of the main burner, the vortex generators arranged next to one another around a circumference of the duct.

5. The premixing burner as claimed in claim 4,

wherein each vortex generator has three surfaces around which flow can take place freely, which surfaces extend in the direction of flow, a first surface forming a top surface and a second and third surface forming side surfaces,

wherein the side surfaces abut a same wall segment of the duct and meet at an acute angle to form a V-shape,

wherein the top surface is oriented at an angle to the duct wall and an edge of the top surface contacts the duct wall extending transversely to the flow direction at the same wall segment as the side walls,

and wherein longitudinally directed edges of the top surface abut longitudinally directed side surface edges protruding into the flow duct.

6. A premixing burner, comprising:

a centrally arranged pilot burner;

a plurality of main burners each having a duct arranged around the pilot burner;

means for injecting at least one of a gaseous and liquid fuel into the duct of each of the main burners as a secondary flow into a gaseous main flow; and

,

a plurality of vortex generators mounted in the duct of each of the main burners upstream of an outlet of the main burner, the vortex generators arranged next to one another around a circumference of the duct,

wherein each vortex generator has three surfaces around which flow can take place freely, which surfaces extend in the direction of flow, a first surface forming a top surface and a second and third surface forming side surfaces,

wherein the side surfaces abut a same wall segment of the duct and meet at an acute angle to form a V-shape,

wherein the top surface is oriented at an angle to the duct wall and an edge of the top surface contacts the duct wall extending transversely to the flow direction at the same wall segment as the side walls,

and wherein longitudinally directed edges of the top surface abut longitudinally directed side surface edges protruding into the flow duct.

7. The premixing burner as claimed in claim 6, wherein the pilot burner comprises two hollow conical partial bodies positioned to define a conical space aligned in the direction of flow, the partial bodies being positioned with respective center lines offset relative to one another so that adjacent walls of the two partial bodies form along their length longitudinal ducts for a tangentially directed flow of combustion air into the conical space and longitudinally distributed gas inlet openings provided in the walls of the two partial bodies in the region of the longitudinal ducts.