The normal cause is thought to be “over insertion” of the tube into the combustion area (insertion beyond the 1/4" recom- mended recess in the tube entry tunnel). This may or may not be the cause. The following are additional conditions that need be considered when tube burn-off is experienced.
Start Helper™ NOZZLE LINE HEATER
• Restricted flue passages in the equipment due to soot or scale. The restriction causes back pressure in the combus- tion area forcing 2000˚F flue gases back around the air tube entry tunnel. This causes metal fatigue and inevitable tube burn-off.
• Excessive CO2 operating levels. The higher CO2 operation levels produce higher flame temperatures and higher com- bustion area temperatures. Flame temperatures @ 14% CO2 can exceed the 2300˚ ratings of the combustion refractory. Failure of the combustion refractory will eventually lead to tube burn-off and/or heat exchanger failure.
The Beckett Start Helper™ is an easy-to-use nozzle line heater which maintains oil temperature between 120 to 130° during burner off cycle regardless of stored oil temperature or duration of off cycle.
The Start Helper™ is continuously powered, with a solid state, self-regulating heating element to maintain constant temperature. The burner always starts with pre-heated oil, assuring improved atomization, ignition, combustion and fuel efficiency. Fits Beckett and most other burners with same size nozzle line. 120v AC.
CAT. NO. MFG. NO. EACH 4H517
51621 $69.09
• Large, Uninsulated air tube entry tunnel openings. Air tube tunnels should be close fitting, but not touching the burner air tube. Large air tube tunnels allow direct/radiated heat to bear directly on the tube causing distortion and eventual burn off.