A combustion system such as a furnace or boiler includes a perforated reaction holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).

Described is a device (11) for controlling the combustion of a burner (1), comprising: first means (12) for measuring the fuel flow rate (Vg); second means 13 for measuring the flow rate of the comburent (Va) first operator means (14) for controlling the opening of an inlet valve (5) as a function of the quantity of fuel to be supplied to the burner (1); second operator means (15) for controlling the comburent flow regulator means (8) as a function of the quantity of comburent to be supplied to the burner (1); According to this invention, the device (11) comprises a unit (16) for controlling the first operator means (14) and the second operator means (15) as a function of the values measured by the first measuring means (12) and by the second measuring means (13).

A combustion system outputs fuel gas from a plurality of fuel ejectors toward a forward end of a burner wall and preheats a perforated flame holder by sustaining combustion reaction of the fuel gas at combustion zone between the burner wall and a perforated flame holder. The combustion system then outputs fuel gas from the fuel ejectors onto the perforated flame holder and sustains a combustion reaction of the fuel gas within the perforated flame holder.

An apparatus capable of monitoring and adjusting an in-furnace combustion condition in real time, having: a furnace having a heating chamber, a combustor, a charging door, an exhaust gas flow port, and an exhaust gas flow pipe, wherein the combustor is used for introducing fuel and/or an oxygen-containing gas into the heating chamber to form a flame, the charging door is used for adding a raw material, and the gas generated by combustion in the heating chamber enters the exhaust gas flow pipe through the exhaust gas flow port; two sensors of the same type arranged at different positions in the exhaust gas flow pipe; and a control device receiving signals of the two sensors and adjusting, according to a difference between the signals, the amount of the fuel and/or the oxygen-containing gas entering the combustor.

A process and plant for preheating a metal charge fed in continuous to an electric melting furnace through a preheating tunnel provided with side walls, a vault and a horizontal conveyor, wherein the metal charge is enveloped in countercurrent by fumes or exhaust gases exiting from the electric melting furnace, includes causing an air intake from the surrounding environment through openings along the preheating tunnel to complete the combustion of the fumes or exhaust gases. The intake is regulated by acting on suction fans and/or on the openings, based on measurements by temperature sensors and/or the composition of the outgoing gases in or downstream of the terminal part of the tunnel. The metal charge is enveloped by jets of gas ejected through a plurality of nozzles arranged non-uniformly longitudinally on the vault of the tunnel, with a greater concentration on the top of the vault of the tunnel.