SNCR (NOx Control)

Engineered Performance.

Wellons utilizes a urea-based selective non-catalytic reduction (SNCR) system to lower the NOx emissions in the flue gas from the boiler system. The SNCR system is designed to lower the uncontrolled NOx emissions in the stack flue gas by approximately 50%.

SNCR Urea Injection Illustration

Wellons Electrostatic Precipitator - ESP


The SNCR system injects an atomized urea solution into the boiler combustion chamber. The urea injection is controlled based on a signal from the flue gas NOx monitor in the exhaust stack (part of the CEMS system). The amount of urea required will depend on the amount of NOx to be removed from the flue gas.

The injection locations inside the combustion chamber are selected to have the proper flue gas temperatures, have good mixing of the urea with the flue gas, and have the proper residence time to convert the NOx and urea into nitrogen and water vapor.


  • Control Modules

  • Distribution Panels

  • Fluid Atomizing Injectors

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