A plugging resistant, highly stable free-jet burner and method which provide Ultra-Low NO.sub.x emissions using (a) large free-jet ejection ports, (b) a wide tip-to-tip spacing, and (c) auxiliary stabilization tips in the throat of the burner which are highly resistant to plugging and also produce very low levels of NO.sub.x emissions.

A burner and methods of using the burner. The burner utilizes bypass conduits to separate the combustion air that is passed to the primary combustion zone into two or more portions. The two portions are injected into the primary combustion zone at different points so as to reduce the flame temperature. A NOx reducing medium may be mixed with the combustion air in the bypass conduit. The NOx reducing medium may be flue gases from a combustion chamber having the primary combustion zone.

The present invention relates to a method for operating a lean premix burner of an aircraft gas turbine, where fuel and primary supporting air are supplied by means of a supporting burner (pilot burner) arranged centrically to the burner axis, where secondary air surrounding the supporting burner is supplied, and where fuel and air are supplied by means of a main burner, characterized in that the primary supporting air is supplied in an amount of 5 vol % to 10 vol % of the total air quantity, that the secondary supporting air is supplied in an amount of 5 vol % to 20 vol % and that 35 vol % to 75 vol % of the total air quantity are supplied via the main burner in the partial load range and in the full load range.

A burner includes a porous support and a combustion tube along which is mounted the porous support. The combustion tube has one or more openings configured to pass fuel to the porous support. The combustion tube is formed by a plurality of tubular modules assembled together. The burner includes at least one distribution tube extending inside the combustion tube and configured to distribute fuel in a predetermined manner in the combustion tube.

A burner apparatus and method of operating the burner apparatus include a burner housing, and a group of fuel and air swirlers maintained by the burner housing, with the group of fuel and air swirlers supplied by a common fuel and air source. The fuel and air can be directed to one or more of the fuel and air swirlers at a time. Each fuel and air swirler among the group of fuel and air swirlers can mix the fuel and the air, resulting in a combustible mixture of the fuel and the air downstream of the group of fuel and air swirlers. The burner apparatus be implemented as a low NOx multi-port burner apparatus.

A plugging resistant, highly stable free-jet burner and method which provide Ultra-Low NO.sub.x emissions using (a) large free-jet ejection ports, (b) a wide tip-to-tip spacing, and (c) auxiliary stabilization tips in the throat of the burner which are highly resistant to plugging and also produce very low levels of NO.sub.x emissions.

A reverse-jet swirl pulverized coal burner with multi-stage recirculations includes a pre-combustion housing, a primary coal-air structure, a rich-lean output structure, an inner secondary air structure, and an outer secondary air structure. The pre-combustion housing has a pre-combustion chamber and a housing outlet. The primary coal-air structure is configured to separate a primary coal-air flow into a fuel-rich coal-air flow and a fuel-lean coal-air flow. The rich-lean output structure is configured to output the fuel-lean coal-air flow and block the fuel-rich coal-air flow to make the fuel-rich coal-air flow reversely flow to the pre-combustion chamber. The inner secondary air structure is configured to introduce an inner secondary air into the pre-combustion chamber, thereby forming a first-stage recirculation zone in the pre-combustion chamber and forming a second-stage recirculation zone. The outer secondary air structure is configured to form a third-stage recirculation zone at the housing outlet.

A burner and methods of using the burner. The burner utilizes bypass conduits to separate the combustion air that is passed to the primary combustion zone into two or more portions. The two portions are injected into the primary combustion zone at different points so as to reduce the flame temperature. A NOx reducing medium may be mixed with the combustion air in the bypass conduit. The NOx reducing medium may be flue gases from a combustion chamber having the primary combustion zone.

A burner apparatus (10) includes a fluid-based flame stabilizer for discharging a stabilized flame therefrom, a burner tile (44), and fuel lances associated with the burner tile. Each of the fuel lances has a discharge nozzle (40). A Coanda feature (34) having a Coanda surface directs a portion of the stabilized flame from the passage defined by the burner tile at the discharge end of a primary flow passage (32) toward at least one first fuel lance of the plurality of fuel lances to cross light the at least one first fuel lance. In another embodiment, a method of combustion includes supplying a first gaseous fuel to fuel lances of a burner apparatus and igniting and sustaining combustion of a gaseous fuel by cross lighting at the discharge nozzles of the fuel lances by flow from the fluid-based flame stabilizer along a Coanda surface of a Coanda feature toward the discharge nozzles.

A premix burner made up of an air inlet tube of length L and a single specific gas injection, the gas injection includes an upstream gas injector, a mixer, a downstream gas injection situated at a distance L3 from an upstream end of the air inlet tube and a stabilizing element, where the gas injection constitutes a one-piece mechanical assembly that ensures a self-stable elementary flame.