474results about "Staged combustion" patented technology

A process is provided for combusting a low heating value fuel gas in a combustor to drive an associated gas turbine. A low heating value fuel gas feed is divided into a burner portion and a combustion chamber portion. The combustion chamber portion and a combustion air are conveyed into a mixing zone of the combustor to form an air / fuel mixture. The burner portion is conveyed into a flame zone of the combustor through a burner nozzle while a first portion of the air / fuel mixture is conveyed into the flame zone through a burner port adjacent to the burner nozzle. The burner portion and first portion of the air / fuel mixture are contacted in the flame zone to combust the portions and produce flame zone products. The flame zone products are conveyed into an oxidation zone of the combustor downstream of the flame zone while a second portion of the air / fuel mixture is also conveyed into the oxidation zone. The second portion is combusted in the oxidation zone in the presence of the flame zone products to produce combustion products. The combustion products are conveyed into the associated gas turbine and drive the gas turbine.

A nozzle comprising a nozzle body having an inlet face, an outlet face, and an inlet flow axis passing through the inlet and outlet faces, and two or more slots extending through the nozzle body from the inlet face to the outlet face. Each slot has a slot axis and the slot axis of at least one of the slots is not parallel to the inlet flow axis of the nozzle body. In another embodiment, the nozzle comprises a nozzle body having an inlet face, an outlet face, and an inlet flow axis passing through the inlet and outlet faces, and two or more slots extending through the nozzle body from the inlet face to the outlet face, each slot having a slot axis, wherein none of the slots intersect other slots and all of the slots are in fluid flow communication with a common fluid supply conduit. The nozzles may be used to inject secondary fuel in a burner system having a central burner combusting a primary fuel surrounded by secondary fuel injection nozzles.

A system and process are provided for converting a light hydrocarbon gas to a synthetic heavier hydrocarbon liquid. The system includes an autothermal reformer, a Fischer-Tropsch reactor and a Brayton cycle that are structurally and functionally integrated. In the practice of the process, a mixture of a hydrocarbon feed gas, a compressed air feed and process steam is fed to the autothermal reformer to produce a synthesis gas. The synthesis gas is fed to the Fischer-Tropsch reactor where it is catalytically reacted to produce heavy hydrocarbons. The outlet from the Fischer-Tropsch reactor is separated into water, a low heating value tail gas, and the desired hydrocarbon liquid product. The water is pressurized and heated to generate process steam. The tail gas is heated and fed with compressed air and steam to the Brayton cycle having a combustor and a series of power turbines and compressors. The tail gas and air feed are burned in the combustor to produce a combustion gas that is used to drive a power turbine linked by a shaft to an air compressor, thereby driving the air compressor. The system further includes a plurality of heat exchangers that enable heat to be recovered from the outlet of the autothermal reformer. The recovered heat is used to make the process steam as well as to preheat the hydrocarbon feed gas before it is fed to the autothermal reformer, preheat the synthesis gas before it is fed to the Fischer-Tropsch reactor and preheat the tail gas before it is fed to the combustor.

An oxy / fuel combustion system having a furnace arranged and disposed to combust a fuel to form a combustion fluid. The system further includes a convective section having at least one heat exchanger arranged and disposed to exchange heat between the combustion fluid and steam for use in a steam turbine. A flue gas recycle is arranged and disposed to recycle at least a portion of the combustion fluid as a recycled flue gas, the flue gas recycle having at least two expellant locations downstream of a primary combustion zone. The system includes a flow control mechanism that provides controlled amounts of the recycled flue gas to the at least two expellant locations to control temperature of the steam.

This invention proposes innovative techniques of NOx reduction in boiler operation through an adaptation of staged combustion in combustion boilers. In preferred processes, air is fed into an air separation unit, and a nitrogen-enriched stream is combined with air to produce a nitrogen-enriched first stage air stream, and at least a portion of an oxygen-enriched stream is mixed with air to produce an oxygen-enriched second stage air stream. A reduction in NOx and increase in efficiency is promoted by the inventive processes and systems.

Low NOx emission industrial burner, adapted to operate both in a flame or stage mode and in a flameless mode, so that also the heating step of the chamber of a furnace may be made by means of the same burner, without providing a pilot burner, thus ensuring very low NOx emissions for the whole operation range of the burner and for the whole range of temperatures in the chamber. The combustion process, made by means of said burner, provides for the possibility to combine the stage mode operation with the flameless mode operation.

A fuel flexible furnace, including a main combustion zone, a reburn zone downstream from the main combustion zone, and a delivery system operably coupled to supplies of biomass and coal and configured to deliver the biomass and the coal as ingredients of first and reburn fuels to the main combustion zone and the reburn zone, with each fuel including flexible quantities of the biomass and / or the coal. The flexible quantities are variable with the furnace in an operating condition.

A method to reduce mercury in gas emissions from the combustion of low rank coal in a combustion system including: combusting coal having a low chlorine content in the combustion system, wherein elemental mercury (Hg0) is released in the flue gas produced by the combustion of the low rank coal; releasing chlorine into the flue gas by combusting a coal having a high chlorine in the combustion system; reacting the elemental mercury and released chlorine in the flue gas to oxidize the mercury; adsorbing at least a portion of the oxidized mercury generated by the combustion of the coal with an adsorbent in the flue gas, and collecting the adsorbent with the oxidized mercury in a combustion waste treatment system.

A method and apparatus for combustion of a fuel in which a first-stage fuel and a first-stage oxidant are introduced into a combustion chamber and ignited, forming a primary combustion zone. At least about 5% of the total heat output produced by combustion of the first-stage fuel and the first-stage oxidant is removed from the primary combustion zone, forming cooled first-stage combustion products. A portion of the cooled first-stage combustion products from a downstream region of the primary combustion zone is recirculated to an upstream region of primary combustion zone. A second-stage fuel is introduced into the combustion chamber downstream of the primary combustion zone and ignited, forming a secondary combustion zone. At least about 5% of the heat from the secondary combustion zone is removed. In accordance with one embodiment, a third-stage oxidant is introduced into the combustion chamber downstream of the secondary combustion zone, forming a tertiary combustion zone.

Processes and systems for producing glass fibers having regions devoid of glass using submerged combustion melters, including feeding a vitrifiable feed material into a feed inlet of a melting zone of a melter vessel, and heating the vitrifiable material with at least one burner directing combustion products of an oxidant and a first fuel into the melting zone under a level of the molten material in the zone. One or more of the burners is configured to impart heat and turbulence to the molten material, producing a turbulent molten material comprising a plurality of bubbles suspended in the molten material, the bubbles comprising at least some of the combustion products, and optionally other gas species introduced by the burners. The molten material and bubbles are drawn through a bushing fluidly connected to a forehearth to produce a glass fiber comprising a plurality of interior regions substantially devoid of glass.

A burner for producing a plug-like flow and low NOx emissions. The burner has a central air jet and plural staged fuel jets surrounding the central jet. The ratio of the sum of the momentums of vector components of the staged jets along respective axes parallel to the central longitudinal axis of the central jet to the momentum of the central jet along that axis is within the range of 0.5 to 1.5 and most preferably 0.8.

A gas turbine combustor burns a fuel mixture at a high combustion efficiency and a low NOx emission, is simple in construction and exercises improved ignition performance, and an ignition method can efficiently igniting a fuel mixture in the gas turbine combustor. A gas turbine combustor provided with fuel nozzles each having a pilot fuel injection nozzle and a main fuel injection nozzle, and fuel nozzles each having a pilot fuel injection nozzle and a main fuel injection nozzle. The fuel nozzle disposed close to an igniter is provided with a local fuel injection port through which fuel is jetted out from a predetermined position in an air passage in the main fuel injection nozzle to create a combustible fuel mixture zone in the vicinity of the igniter at least while the igniter is in an ignition operation.

A solid fuel burner using a low oxygen concentration gas as a transporting gas of a low grade solid fuel such as brown coal or the like and a combustion method using the solid fuel burner are provided. The solid fuel burner comprises a means for accelerating ignition of the fuel and a means for preventing slugging caused by combustion ash from occurring. Mixing of fuel and air inside a fuel nozzle 11 is accelerated by that an additional air nozzle 12 and a separator 35 for separating a flow passage are arranged in the fuel nozzle 11, and the exit of the additional air nozzle 12 is set at a position so as to overlap with the separator 35 when seeing from a direction perpendicular to a burner axis, and additional air is ejected in a direction nearly perpendicular to a flow direction of a fuel jet flowing through the fuel nozzle 11. An amount of air from the additional air nozzle 12 is varied corresponding to a combustion load. By increasing the amount of air from the additional air nozzle 12 at a low load operation, an oxygen concentration of a circulation flow 19 formed in a downstream portion outside the exit of the fuel nozzle 11 is increased to stably burn the fuel. By decreasing the amount of air from the additional air nozzle 12 at a high load operation, a flame is formed at a position distant from the fuel nozzle 11 to suppress radiant heat received by structures of the solid fuel burner and walls of the furnace.

In a furnace having a primary combustion zone for combustion of a fuel and oxidant, an in-furnace method for reducing nitrogen oxides in combustion products generated in the primary combustion zone in which at least one fluid fuel selected from the group consisting of natural gas, hydrogen, CxHy compounds, CxHyOz compounds and mixtures thereof in an amount in a range of about 2.0% to about 25% of a total heat input to the furnace and at least one nitrogenous compound selected from the group consisting of ammonia, amines, urea, cyanuric acid and mixtures thereof are injected into the furnace downstream of the primary combustion zone, forming an overall fuel-lean NOx-reduction zone.

A burner includes a first burner port that generates a first flame, a gap that surrounds the first burner port, and a plurality of second burner ports that are disposed on either side of the gap, the second burner ports generating second flames to hold the first flame. The first burner port combusts a first mixture (lean mixture) to generate the first flame (lean flame). The first mixture includes air more than fuel gas. A gap that surrounds the first burner port is formed. A plurality of the second burner ports are arranged on either side of the gap. The second burner ports combust a second mixture (rich mixture) to generate the second flames (rich flames) and hold the first flame. The air-fuel ratio of the second mixture is smaller than the first mixture.

The present invention discloses a novel apparatus and method for operating a gas turbine combustor having a structural configuration proximate a pilot region of the combustor which seeks to minimize the onset of thermo acoustic dynamics. The pilot region of the combustor includes a generally cylindrical extension having an outlet end with an irregular profile which incorporates asymmetries into the system so as to destroy any coherent structures.

In a rich-lean burner, a gap formed between a lean-flame port and a rich-flame port is in fluid communication with a supply passage through which a lean gas is to be supplied to the lean-flame port. One or more projections are provided on at least one of partition plates disposed between the gap and the lean-flame port and between the gap and the rich-flame port. A recessed portion is formed at a region adjacent to the lean-flame ports at an interface between the distal end of at least one of the projections protruding from one of the partition plates and the other of the partition plates, the distal end of the at least one of the projections being partially not in contact with the other of the partition plates to provide a clearance through which the lean gas is allowed to be supplied to the gap.

A receiver front end capable of receiving and processing intraband non-contiguous carrier aggregate (CA) signals using multiple low noise amplifiers (LNAs) is disclosed herein. A cascode having a “common source” input stage and a “common gate” output stage can be turned on or off using the gate of the output stage. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input stage of each cascode. Further switches used for switching degeneration inductors, gate / sources caps and gate to ground caps for each legs can be used to further improve the matching performance of the invention.

A lean premix burner for a gas turbine having at least one fuel supply ring 4 fitted with primary fuel nozzles 8 and additional secondary fuel nozzles 9, and a method of operation for this lean premix burner.

Improvements in methods by which new or used coal fired boilers whether designed for coal or oil or natural gas firing can substantially improve their technical operation and reduce their capital and operating costs by implementing process steps that (a) minimize the adverse impacts of coal ash and slag on boiler surfaces and particulate emissions, which will improve coal combustion efficiency and facilitate the use of oil or gas designed boilers for coal firing, (b) drastically reduce the loss of water used to transport coal in slurry form to power plants, (c) minimize the combined total nitrogen oxides (NOx), sulfur dioxide (SO2), mercury (Hg), and carbon dioxide (CO2) emissions, (d) separate and permanently sequester carbon dioxide and (e) improve the coal and solid fuel combustion efficiency. In the method includes whereby slag formed from solid fuel ashes during combustion in boilers or furnaces is suppressed by introducing additional air in a post-primary combustion zone to lower the combustion gas temperatures below temperatures at which the ash softens or liquefies and adheres to boiler or furnace surfaces.

A burner used in an exhaust purifying device that purifies exhaust in an exhaust pipe of a diesel engine is provided with a tubular flame stabilizer including an ejection port from which fluid generated through combustion is ejected. The flame stabilizer includes a connecting passage, which connects the interior of the flame stabilizer and the exterior of the flame stabilizer. A recirculation unit is arranged at an outer side of the flame stabilizer. The recirculation unit includes a flow receiving portion that receives the fluid ejected from the ejection port, and an outer guiding portion that guides the fluid received by the flow receiving portion to the connecting passage.

An air-blast fuel injector is disclosed which includes an outer air circuit having an exit portion, an inner air circuit having an outlet configured to direct air toward the exit portion of the outer air circuit, and a fuel circuit radially outboard of the inner air circuit and having an exit communicating with the outer air circuit upstream from the exit portion of the outer air circuit.