Supplied By www.heating spares.co Tel. 0161 620 6677
22
DOMINA PLUS F 24 - 30 E
FERELLA EXTRA F 24 - 30 MEL
Version - 09.2002
Burner assembly
The burner assembly is composed of 12 or 16 burner stages. Each stage is composed of two pressed steel
half bearings, with a suitably cut stainless steel head. Gas enters at the bottom of the stage. Thanks to the
special Venturi-tube shape of the bottom portion of the stage, the gas "injected" by the nozzle carries with it
the primary air needed for combustion. The air-gas mixture thus formed inside the stage is evenly distributed
on the burner head. Combustion takes place homogeneously over the entire length of the single stages, with
the contribution of the secondary air from the bottom of the burner mount and from the combustion chamber
itself. The set of stages in operation forms a single belt of flame, light blue in colour, whose size varies according
to the nozzle gas pressure, that is the boiler capacity modulation.
Detection electrode
Made of the same material as the ignition electrode, it is set 11 mm from the
burner head. Combustion causes the flame atmosphere to ionize, making it
conductive. Thanks to the mass of the burner, making a suitable potential with
the electrode produces a flow of direct current on it. For our cards, it is
necessary to have an ionizing current of at least 5 µA to detect a flame. A
signal is normally obtained ranging from 10 to 40µA (see chap. 3.1).