A low-NOx end-fired furnace for melting glass equipped with an overhead burner includes an inlet duct for oxidizer, including 15% to 30% of oxygen, in its upstream wall, a duct for receiving the combustion flue gases in its upstream wall, and a sonic injection system including at least one injector for injecting a jet of a gas at a speed at least equal to 80% of the speed of sound, referred to as a sonic injector, opening into the upstream wall or opening into the duct for receiving the combustion flue gases, the sonic injector injecting its gas counter-current to the stream of the combustion flue gases that are heading toward the duct for receiving the combustion flue gases.

A flue gas denitration system includes a catalytic reactor accommodating a plurality of catalytic modules, into which a flue gas flows, and a flue gas heater provided on an upstream side of the catalytic reactor in a flow direction of the flue gas. In the flue gas denitration system, switched are a first denitration state in which the flue gas is denitrated by using the plurality of catalytic modules in the catalytic reactor and a second denitration state in which the flue gas is denitrated by using a catalytic module(s) less than those used in the first denitration state while a temperature of the flue gas flowing into the catalytic reactor is made higher than that in the first denitration state by using the flue gas heater. Thus, by making the temperature of the flue gas flowing into the catalytic reactor higher, it is possible to suppress deterioration in denitration performance in the case of using part of the plurality of catalytic modules for denitration.

A low-NOx end-fired furnace for melting glass equipped with an overhead burner includes an inlet duct for oxidizer, including 15% to 30% of oxygen, in its upstream wall, a duct for receiving the combustion flue gases in its upstream wall, and a sonic injection system including at least one injector for injecting a jet of a gas at a speed at least equal to 80% of the speed of sound, referred to as a sonic injector, opening into the upstream wall or opening into the duct for receiving the combustion flue gases, the sonic injector injecting its gas counter-current to the stream of the combustion flue gases that are heading toward the duct for receiving the combustion flue gases.

A method and a boiler for decreasing the amount of nitrogen oxides in flue gases of a boiler, which flue gases are generated in the combustion of fuels and air. The boiler has a water circulation system comprising superheaters and a furnace for combustion of fuel and for generating flue gases that contain nitrogen oxides, which flue gases mainly flow upwards in the furnace and further to the superheater zone and via other heat recovery surfaces of the boiler out of the boiler, and a nitrogen oxides reducing agent is introduced into the flue gases. The nitrogen oxides reducing agent is introduced into the flue gases prior to the superheater zone, after the temperature of the flue gases is decreased by at least one heat exchanger that is located upstream of the nose of the boiler and upstream of the introduction of the nitrogen oxides reducing agent.

A burner includes a hot gas zone and an outer zone, a primary air feed line, a secondary air feed line, and a fuel feed line. The secondary air feed line includes three concentric cylindrical tubes. The fuel feed line is arranged concentrically around the secondary air feed line. A first dead volume exists inside the burner between the secondary air feed line and the fuel feed line. The fuel feed line has a nozzle construction on the hot gas side. A second dead volume is arranged between the secondary air feed line and the fuel feed line on the outer side zone. The primary air feed line is arranged concentrically around the fuel feed line.

An arrangement for adjusting the ratio between supplied amounts of fuel (PA) and air (I) in a burner, which is intended for a gaseous and/or liquid fuel is disclosed. The burner comprises a fuel and air mixing zone, a fuel supply conduit adapted to supply the mixing zone with a given inlet flow of fuel, a combustion air supply means adapted to supply the mixing zone with a given inlet flow of combustion air, and burner automation. The burner automation contains measuring instruments. The burner has its mixing zone accompanied by a combustion chamber which is in communication with a flue gas conduit. The combustion chamber or flue gas conduit has at least one catalytic zone. In the arrangement, the measuring instruments include at least one sensor, such as a lambda sensor, measuring the amount of residual oxygen in flue gases (flue gas oxidation/reduction potential). In the arrangement adjustment for an inlet flow (Q.sub.I, Q.sub.Itot) of combustion air generated by the combustion air (I) supply means (determined as a volume flow per unit time), as well as the adjustment for an inlet flow (Q.sub.PA, Q.sub.PAtot) of fuel arriving in the mixing zone by way of the fuel supply conduit (determined as a volume flow per unit time), by means of burner automation, is based on the amount of residual oxygen measured from flue gases (S) with the measuring instrument, by way of which the burner automation adjusts the relative ratio between said inlet flow (Q.sub.I, Q.sub.Itot) of combustion air as well as the inlet flow (Q.sub.PA, Q.sub.PAtot) of fuel in such a way that the amount of residual oxygen is within the range of 0.05-0.5% in flue gases prior to the catalytic zone.

A thermal power generation system includes: a boiler; at least one steam turbine; a generator; a condenser; at least one low-pressure feed water; a high-pressure feed water pump; at least one high-pressure feed water heater capable of heating water pumped by the high-pressure feed water pump by utilizing extracted steam; a catalyst device including at least one kind of catalyst capable of promoting reduction reaction of nitrogen oxide and oxidation reaction of metallic mercury, the nitrogen oxide and the metallic mercury both being contained in the exhaust gas; at least one mercuric oxide removing device capable of removing mercuric oxide produced by the oxidation reaction of the metallic mercury from the exhaust gas; and an exhaust gas temperature adjustment device capable of adjusting a temperature of the exhaust gas at the catalyst device, by adjusting heating of the water by the at least one high-pressure feed water heater.

A low-NOx end-fired furnace for melting glass equipped with an overhead burner includes an inlet duct for oxidizer, including 15% to 30% of oxygen, in its upstream wall, a duct for receiving the combustion flue gases in its upstream wall, and a sonic injection system including at least one injector for injecting a jet of a gas at a speed at least equal to 80% of the speed of sound, referred to as a sonic injector, opening into the upstream wall or opening into the duct for receiving the combustion flue gases, the sonic injector injecting its gas counter-current to the stream of the combustion flue gases that are heading toward the duct for receiving the combustion flue gases.

A method for conducting combustion in a fluidized bed furnace, in particular having a sand bed, according to which a flow of primary combustion air is blown through the bed, the fuel consisting in particular of organic waste, or of municipal waste, or of sludge from purifying stations, it being possible to inject secondary air (5a) into the space (5) in the furnace located above the bed; in order to limit the production of nitrogen oxides NOx and nitrous oxide N2O: the nitrous oxide N2O and nitrogen oxide NOx content of the fumes at the outlet of the furnace are measured (12, 20); the temperature of the fluidized bed is controlled to keep it at the highest admissible value at which the production of nitrous oxide N2O is substantially reduced, while the production of nitrogen oxides NOx is not substantially increased; and the excess air in the fluidized bed is controlled to keep it at the lowest admissible value at which the production of nitrogen oxides NOx is reduced without adversely affecting the combustion and the temperature of the bed.

A gas conditioning system removes contaminants including carbon dioxide from flue gas, such as flue gas of a marine vessel, and includes a rotating backed bed assembly. The rotating packed bed assembly fluidly connects to an exhaust port of an engine, and receive a flue gas from the exhaust port. The rotating packed bed assembly includes a first rotating packed bed having an absorption agent to absorb a portion of the carbon dioxide from the flue gas, and a second rotating packed bed to receive the absorption agent from the first rotating packed bed and desorb at least some of the portion of the carbon dioxide from the absorption agent.