User Guide

16
Examples of Proper
Nozzle Selection
The following recommendations are solidly based on many years
of field experience and laboratory testing. But, like most
recommendations, they are subject to exceptional cases or
conditions.
Figure 17 Hollow Air Pattern
Burners with Hollow Air Pattern The burner air pattern
shown above produces a very definite hollow “air spray,” with no
measurable air velocity at the center of the pattern. The angle of
this particular air spray shows it will require a 70° to 80° hollow
cone nozzle for good matching. Asolid cone nozzle, or one with a
narrow angle, would produce a poor match and probably create
smoke in the center of the flame, which couldn’t be cleaned up by
any adjustment of air.
Figure 18 Solid Air Pattern
Burners with Solid Air Patterns The burner air pattern
shown above produces a moderate form of solid “air spray.” In
actual tests this burner would show a slightly better CO
2
reading
with a solid cone nozzle. This would become even more
pronounced in burners showing higher air velocities at the center
of the pattern.