Bloom’s baffle burner recirculates furnace gas into the flame. Its appearance is deceptively simple consisting of a body, gas nozzle, baffle, and port. Air enters the burner body directly and the gas passes through the body separated from the air with the fuel tube. The refractory baffle separates the body from the burner block (port), which is within the wall of the furnace.
Air passes into the port through a series of holes around the circumference of the baffle. Gas enters the port through a hole in the center of the baffle burner. Only after the air and gas enter the port areas do they mix together and allow ignition to occur.
The ceramic baffle provides support to the gas tube and is a radiation shield between the flame and the internal burner parts. Baffle hole and port geometries determine the flame characteristics, such as shape and luminosity. Geometry also influences the amount of furnace gases recirculation into the port, a major factor in reducing NOx levels.
The baffle burner passages are essentially nozzles which create a jet effect on the exit side. A jet exiting a nozzle creates a recirculation zone and a low pressure area at the exit. The jet phenomenon anchors the flame in the port, ensures thorough mixing of the air and fuel, and provides the energy to recirculate POC into the port.
Subtle geometric changes to the baffle and port affect the jet characteristics. The standard Bloom burner baffle is effective in recirculation furnace gases and is inherently a low NOx design. Bloom’s Low and Ultra Low NOxTM baffle burners represent an optimization of the geometry to maximize furnace gas recirculation into the flame.