Multi Zone Low NOx Burners & Over Fire Air Systems

Multi Zone LNB Tuning Features


Innovative shop assembly and quality control process

  • Complete fabrication and assembly performed by our experienced team
  • Custom jigs are used for assembly to ensure proper alignment of all moving parts
  • QC job traveler for each burner

Multi Zone LNB Burner Design and Unit Review

  • NOx Burner Custom DesignCoal and boiler operating data review
  • Test data review
  • CFD modeling of air flow and chemical species of combustion
  • 3D Solidworks models of the combustion system is made after field measurements.
  • This helps with mechanical design and reducing installation problems.
  • Once the baseline CFD model is completed, the addition of Low NOx burners with and without Overfire Air can be tested.
  • Elevation changes of the OFA can be tested as well as various mill and burner combinations and operating conditions.
  • To maximize NOx reduction when overfire air is used, burner throat modifications are supplied for optimum performance
  • Silicon carbide interlocking segments and 309 stainless steel retaining ring

NOx concentration profiles for the baseline case

NOx concentration profiles for the baseline case

Net NOx formation rate for the baseline case

Net NOx formation rate for the baseline case

P&I Over Fire Air Designs

Over Fire Air System

Over Fire Air System

Requires plant specific solutions based on availability of secondary air supply and the best elevation for NOx and CO reduction.

Compartmentalized OFA Design
OFA Design Close Up

Typical OFA Designs

  • Compartmentalized windbox and OFA added
  • Secondary air header added
  • Finger duct OFAs

Compartmentalized OFA

Compartmentalized OFA

Finger Duct OFA

Finger Duct OFA

Common Windbox Conversion

Common Windbox Conversion

P&I OFA Designs

Larger OFA ports are used above and outboard of the burners to more efficiently reduce NOx and CO that tend to flow up the corners of a boiler.

OFA Ports
OFA Ports