Combustion burner with fixed vanes

A combustion burner, configurable for tuning to an appliance to form a combined system for adjusting exhaust flow and heat transfer, comprising:

• a tubular burner body having a sidewall, an air inlet end, a combustion gases outlet end and a central bore that extends between the air inlet end and the combustion gases outlet end being insertable into the appliance;
• a swirl generator insert positioned across the central bore, the swirl generator insert being a convergent nozzle having vanes configured to impart a swirl pattern with minimal pressure loss to an axial flow of forced air passing from the air inlet end through the swirl generator insert, the swirl generator insert being relatively thin such that a diameter of the insert exceeds a length of the insert, and the swirl generator insert being removable and replaceable to change vane properties for tuning the combined system;
• an annular fuel gas manifold positioned in the central bore, downstream of the swirl generator insert, the gas manifold having a plurality of gas jets positioned adjacent to the sidewall at spaced intervals 360 degrees around the gas manifold to inject fuel into the swirling axial air flow within the central bore;
• a mixing chamber downstream of the gas manifold to mix fuel gas from the gas jets with the forced air exiting the swirl generator insert to create a fuel/air mixture;
• an annulus spool positioned within the mixing chamber to constrict the central bore and define a diameter of the mixing chamber through which the swirling fuel/air mixture passes, the annulus spool being removable and interchangeable to further tune the combined system by setting the mixing chamber diameter;
• a combustion chamber downstream of the mixing chamber;
• and
• an igniter passage extending through the burner body to position an igniter downstream of the mixing chamber to ignite the fuel/air mixture entering the combustion chamber, wherein the combustion burner is configured for adjustments to the swirl generator insert and the annulus spool to set exhaust velocity, and adjust heat transfer rate and residence time, and combustion efficiency in the combined system.