A burner and methods of using the burner. The burner produces a flame from combustion air and fuel gas. Flue gas, also produced, can be withdrawn and recycled to the burner. A cooling or condition gas, such as ambient air, may be mixed with the flue gas to reduce its temperature. The burner may also utilize a stage injection so that a portion of the produced flue gas is recycled internally.

According to an embodiment, a fired heater includes a fuel and combustion air source configured to output fuel and combustion air into a combustion volume, the combustion volume including a combustion volume wall defining a lateral extent separate from an exterior volume. According to an embodiment, the fired heater includes a boiler heater and the combustion volume wall comprises a combustion pipe defining a lateral extent of the combustion volume, the combustion pipe being disposed to separate the combustion volume from a water and steam volume. The fired heater includes a mixing tube aligned to receive the fuel and combustion air from the fuel and combustion air source. The mixing tube may be separated from the combustion volume wall by a separation volume. The fired heater includes a bluff body flame holder aligned to receive a fuel and combustion air mixture from an outlet end of the mixing tube. The bluff body flame holder may be configured to hold a combustion reaction for heating a combustion volume wall. The combustion volume wall may include a combustion pipe. The combustion pipe may be configured to heat the water in the water and steam volume.

The method is for controlling a deflagration combustion process in a pistonless combustor. The method includes scavenging combustion products of the previous cycle, introducing air into the combustor thereby initiating a flow pattern having a first flow component within the combustor. Air is introduced into the pistonless combustor in a nonparallel angle in relation to the previous air input and thereby creating a second flow component to the flow pattern for increasing speed of combustion propagation. Fuel mixed into the air is introduced for creating a fuel-air mixture flowing within the flow pattern, and igniting the fuelair mixture within the pistonless combustor thereby increasing pressure within the pistonless combustor.

A cylindrical burner apparatus and method which produce low NO.sub.x emissions and low noise levels without being dependent upon a blower, or natural draft, for providing air flow. A flow of combustion air is induced into a cylindrical burner lube by discharging a gas fuel from a plurality of discharge ports located inside the rearward end of the tube. At least some of the discharge ports are oriented to direct jets of the gas fuel toward flame stabilization structures positioned downstream of the discharge ports.

A catalyst regenerator according to an embodiment of the present invention, as a catalyst regenerator that regenerates a coked catalyst separated from a product produced in an endothermic catalytic reaction of a fluidized bed reactor, includes: a reaction chamber that includes a regeneration space, receives the coked catalyst from a standpipe connected to the regeneration space, and discharges a regenerated catalyst to an outlet; a fuel supplier that is connected to the reaction chamber to inject a fuel for combustion into the regeneration space; and a fuel supplier that is connected to the reaction chamber to inject an air for combustion into the regeneration space, wherein the fuel injected from the fuel supplier is a reformed fuel containing hydrogen and carbon monoxide.

A cylindrical burner apparatus and method which produce low NO.sub.x emissions and low noise levels without being dependent upon a blower, or natural draft, for providing air flow or flue gas recirculation. A flow of combustion air is induced into the initial tube pass of the burner by discharging a gas fuel from a plurality of discharge ports located in the initial tube pass. At the same time, a flow of recycled flue gas is induced through a bypass duct between a subsequent tube pass of the burner and the initial tube pass by discharging one or more jets of gas fuel through the bypass duct.

A burner includes a main body having an outer surface and at least partially defining an interior. The main body further includes an upstream end axially spaced from a downstream end. The outer surface includes a burner front face at the downstream end of the main body. An annular cooling air plenum is defined in the main body radially inwardly from the outer surface. A cooling air passage extends from the outer surface to the annular cooling air plenum. A plurality of cooling channels is circumferentially spaced apart from one another along the burner front face. Each cooling channel of the plurality of cooling channels extends from a respective inlet in fluid communication with the annular cooling air plenum to a respective outlet.

A method for burning primary fuel (F1), wherein the primary fuel (F1) comprises at least a first compound containing nitrogen and a second compound comprising sulfur. The method comprises producing primary combustion gas (G1) having a temperature of at least 450° C. and comprising oxygen; feeding the primary fuel (F1) and the primary combustion gas (G1) to a primary process zone (Z1) of a furnace (200); feeding tertiary combustion gas (G3) to a secondary process zone (Z2) of the furnace (200); letting the primary fuel (F1), the primary combustion gas (G1), and/or their reaction products to move from the primary process zone (Z1) via the secondary process zone (Z2) to a tertiary process zone (Z3) of the furnace (200); and feeding quaternary combustion gas (G4) comprising oxygen to the tertiary process zone (Z3) of the furnace (200). An embodiment comprises collecting the primary fuel (F1) from a pulp process. A corresponding system.

A catalyst regenerator according to an embodiment of the present invention, as a catalyst regenerator that regenerates a coked catalyst separated from a product produced in an endothermic catalytic reaction of a fluidized bed reactor, includes: a reaction chamber that includes a regeneration space, receives the coked catalyst from a standpipe connected to the regeneration space, and discharges a regenerated catalyst to an outlet; a fuel supplier that is connected to the reaction chamber to inject a fuel for combustion into the regeneration space; and a fuel supplier that is connected to the reaction chamber to inject an air for combustion into the regeneration space, wherein the fuel injected from the fuel supplier is a reformed fuel containing hydrogen and carbon monoxide.

A insert for a staged fuel burner and processes for using a burner with the insert. The insert has a burner tip that injects a mixture of primary fuel and combustion air into a combustion zone to produce a flame. A staged fuel is also injected into the combustion zone. Prior to being injected into the combustion zone, from the burner tip, the staged fuel, is injected into the burner tip and draws combustion air from the mixer of the burner insert into the burner tip with the staged fuel.