Facts worth knowing about Oil nozzles - Danfoss.com

What produces a greasy malodorous deposit in theboiler and how can it be removed?When an oil-heating plant can be detected from a distance by its smell, themost frequent cause is the interior of the boiler being covered with a blackshiny greasy substance which is not so easy to remove.This substance is usually created when the oil burner has too large anexcess of air. Some of the ignited oil becomes cooled down so violentlythat it is extinguished before being completely burned out.Since the lightest contents in the oil are the first to be burned, what is leftif the oil is not completely consumed are the tars. Tarry deposits areavoidable so long as oil combustion does not involve too much excess air.Also, as high a CO 2 percentage must always be maintained – withoutforgetting the soot count.Tarry deposits can be burnt off, but if they are very thick the advice of achimney cleaning specialist should be sought. Consulting the local firebrigade is also a good idea.Basically, burning-off is a matter of reducing the air supply and increasingboiler temperature by using the boiler thermostat.Tarry deposits most often occur because:• Oil combustion is accompanied by too much superfluous air.• Too low an oil pressure, or a defective nozzle, produce oil drops which aretoo large.27