flame spreader

The air/fuel mixture flows around the bottom of the flame spreader where it burns with a blue flame.

A small plate on the top of the burner (a flame spreader) spreads the flame outwards.

If the pipe is metal and away from combustible material, you can also use a propane torch equipped with a flame spreader to produce a wide, relatively cool flame.

Like most gasoline stoves, the Svea 123 uses an inverted bell-shaped burner topped with a flame spreader (sometimes called a "target burner" or "plate burner" design).

When the lamp is lit, the central draft tube supplies air to the flame spreader that spreads out the flame into a ring of fire and allows the lamp to burn cleanly.

At very low fuel output levels, the fuel will no longer exit with sufficient velocity to fully strike the flame spreader and combustion will consequently be very inefficient, usually indicated by a yellow flame.

The wick rides in between the inner and outer wick tubes; the inner wick tube (central draft tube) provides the "central draft" or draft that supplies air to the flame spreader.

As the vaporized fuel exits the jet, it shoots upward and strikes the bottom of the flame spreader, where it mixes with air that is drawn into the burner housing by convection and, more importantly at higher flow rates, by Bernoulli effect entrainment.

In this type of burner design, flame efficiency depends on how fast the vaporized fuel strikes the flame spreader and on how well the air and vaporized fuel mixes beneath the flame spreader (i.e., the amount of turbulence in the air/fuel mixing zone).