www.maxoncorp.com
combustion systems for industry
Maxon reserves the right to alter specifications and data without prior notice.
© 2013 Copyright Maxon Corporation. All rights reserved.
3 - 18.4 - 8
E-i-5/13 Dual fuel burners - OXY-THERM®FHR
Ratio control requirements
Correct fuel/oxygen ratio control valves should be selected. Trims should be selected to enable use with oxygen. For accurate ratio
control, MAXON SMARTLINK®MRV valves are recommended. Calibrated flowmeters in the fuel and the oxygen lines are
required for establishing accurate volumetric flow rates.
Emission performance
OXY-THERM®FHR burners utilize a patented oxygen staging technology to reduce the formation of NOx in high temperature
furnaces. Through deep staging of the oxidant flow, NOx is controlled to levels typically lower than less advanced oxy-fuel burners.
Best results are achieved in furnaces which are sealed tight from ambient air infiltration or running a slight positive pressure to
prevent the infiltration of nitrogen compounds. Results can vary widely by application. Contact MAXON for estimates and
consultation on best practice.
Exact emissions performance may vary in your application. Contact MAXON for installation-specific estimates and guaranteed
values. No guarantee of emissions is intended or implied without specific, written guarantee from MAXON.
Combustion oxygen and cooling flow
OXY-THERM®FHR burners may be adjusted to operate on ratio, with excess oxygen (oxidizing environment) or with excess fuel
(reducing environment). Typical applications will operate with 1-2% excess oxygen.
If burners are shut down while the furnace remains hot, it is recommended to continue a small flow of oxygen for cooling of the
burner. Alternatively, blower or fan air or can be used for burner cooling during burner shut down. Total elimination of cooling flow in
hot furnaces can result in damage to burner fuel inserts and other parts. For extended shut downs in hot furnaces, it is
recommended that the fuel insert be removed and cooling flow maintained through the burner housing.
Staging ratio control
OXY-THERM®FHR burners feature an adjustable staged oxygen design to optimize heat transfer, flame volume and emissions.
Increasing the staged oxygen produces higher radiative heat flux, larger flame volume and lower NOx emissions; decreasing
staged oxygen produces lower radiative heat flux, smaller flame volume and higher NOx emissions. The numbered hole positions
(1-11) shown on the drawing below correspond with the hole positions indicated on the primary/staged oxygen valve adjustment
graphs available from your MAXON sales representative.
Oxy-fuel burners cannot be set up and operated properly using only pressure measurements for
adjustment. Fully metered oxygen and fuel control systems are required for safe and optimum
performance.
1) Increasing staged
oxygen = higher
radiative heat flux
2) Decreasing staged
oxygen = lower
radiative heat flux
