Call Us Today +1.918.236.6461|
Boiler Burners2022-12-16T19:23:07+00:00

ClearSign Core™
Boiler Burner Technology

Complete systems and retrofits available

Firetube Data Sheet

ClearSign Core™
Boiler Burner Technology

Complete systems and retrofits available


Boiler Burner Industries


OTSG Installations To Central California Customer

A Case Study.

A California based customer approached ClearSign interested in applying the technology to meet the area’s strict emissions regulations. The initial field application scaled the bench scale burner with a firing rate of 250,000 Btu/hr to a 62.5 MMBtu/hr production unit with an emissions target of sub 6 ppm NOx (corrected to 3% O2, volume, dry). 


Our Boiler Burner Technology Partner

Our partnership with California Boiler combines the unique capabilities of our combustion technology with the extensive boiler installation and service experience of California Boiler.  Together, we are able to meet the specific demands of industrial boiler clients. 


Firetube Boiler

A firetube boiler is a type of boiler in which hot gases pass from a combustion zone through one or many tubes running through a sealed container of water. The heat from the gases is transferred through the walls of the tubes by thermal conduction, heating the water and creating steam. Such boilers can be further classified as single pass, two, three or even four pass to denote the number of loops or passes the flue gases make prior to exiting via the stack.

Read More


Watertube Boiler

A watertube boiler is a type of boiler in which water circulates in tubes heated externally by the combustion process. Fuel is burned inside the furnace, creating hot gas which heats water in the steam-generating tubes. The heated water then rises into the steam drum where saturated steam is drawn off the top of the drum. In some services, the steam will reenter the furnace through a superheater to gain additional enthalpy/energy.

Read More


Q – How does the ClearSign Core™ technology compare with respect to legacy equipment?2021-11-15T16:22:46+00:00

The technology provides unprecedented emissions levels (~2.5ppm NOx at 3% O2) compared to traditional equipment without the use of reagents, high excess air conditions or degradations in thermal efficiency

Q – Do I need to operate the boiler any differently with ClearSign Core™ installed?2019-11-18T20:36:02+00:00

No, the Clearsign technology can be operated in exactly the same manner as a legacy burner with regard to start up, ramp rate and shut down protocols.

Q – What fuels do boilers use?2019-11-18T20:23:37+00:00

Natural gas, coals, liquid distillates and biofuels

Q – What modifications do I need to make on my equipment?2019-11-24T02:30:34+00:00

Basically none. The Clearsign Core™ technology is a retrofittable technology that is easily inserted through the same boiler burner openings as the OEM burner.

Q – How can I buy the ClearSign Core™ Technology?2019-11-18T20:26:26+00:00

Clearsign sells its technology through its channel partners or equivalently through Clearsign itself for retrofit applications.

Q – How does ClearSign Core™ Technology Work?2021-11-10T15:25:39+00:00

A distal metallic flameholder and continuous pilot are located downstream of the conventional burner location. Fuel pokers inject fuel downstream and entrain FGR. The cold charge thoroughly mixes as it approaches the flame holder. Thorough mixing of all gas streams, a continuous pilot, and robust flame anchoring ensure excellent combustion stability and superior emissions performance over the operating envelope.

Go to Top