Duct Burners are usually used in combined cycle and they can work either with fresh air (when gas turbine is turned off) or exhaust gas. For this reason they are made from stainless steel in order to resist to the high temperature inside the duct (up to 500 °C).
Critical conditions at the gas turbine discharge (gas flow rate, temperature, stream vorticity and duct lay – out) often require a CFD study, to provide the best solution and guarantee the best performance in terms of operating, maintenance and expected life of the combustion system.

Duct Burners are generally provided in several rows depending of the thermal power required and the general duct arrangement.
Each row is completely filled by stainless steel baffles, which have a modular design that ensure the mixing between gaseous fuel and flue gas or fresh air; such baffles are fixed on gas distributor by screwed nozzles also made from stainless steel.
Fuel gas is injected through a fuel gas distribution tube, equipped with a set of the above mentioned nozzles. Each “multi jets” nozzle injects the fuel gas inside the combustion chamber.
Each distributor is supported by a carbon steel front plate which is flanged to the duct wall. The front plate has also the support for flame scanner and pilot igniter.
This system guarantee a wide turndown range (10 : 1 for each row) and low pollutants production.

Duct Burners Brochure


  • Burner designed to meet Client's specific requirements
  • Highly reliable and efficient
  • Fuel gas is distributed through an internal pipe which support the baffles and the screwed nozzles
  • Capable of burning different kinds of gaseous fuels
  • Can be operated either with fresh air or GT exhaust gas
  • High flame stability over a wide turn - down range


Firing rate up to 15 MW per row
Flame dimensions(*) 1.500 mm
Materials carbon steel
stainless steel
Combustion air up to 550 °C
Turndown 10:1
Pressure drop 10 – 20 mm wg

(*) Flame dimensions vary with firing rate


Natural gas firing with fresh air

NOx 30 mg/Nm3
CO 30 mg/Nm3

Natural gas firing with gas turbine exhaust

NOx - mg/Nm3
CO - mg/Nm3

Post firing emissions are depending from the conditions at gas turbine discharge

(*) ref. to 15% O2 dry flues, fresh combustion air @ ambient temperature; the emissions could be different depending of application and must be evaluate Job by Job


  • Burner with fuel gas equipment (peephole, baffles and stainless steel nozzles)
  • Frontal plate with flanged connections to HRSG and to fuel gas distributor
  • Pilot igniter (High energy, high tension, premixed or non-premixed type with ionization rod)
  • Flame detection system
  • CFD study
  • Local control panel
  • Burner management system (BMS)
  • Piping and instrumentations trains


1 heat recovery steam generator, 1 burner, 12 rows, 185 MW
DEMONT - ENIPOWER Bolgiano (Italy)
1 heat recovery steam generator, 1 burner, 4 rows, 30 MW
ALBAPOWER - Alba (Italy)
1 heat recovery steam generator, 1 burner, 4 rows, 23 MW