Settings for marathon
®
burners with mechanical linkage
dreizler A 3001 E - 18.12.2015 | A 2070 - 1.12 | EN - 09.11.2012
44
12.7.2 Effects on gas to air ratio based on adjustments of the swiveling ranges
1 and
2
The results can - with no changes to the initial position of the dampers - be effected by loosening the ter-
minal screw and moving the air or gas adjustment lever against the air or gas axis.
With an 'outward' lengthening of the swivel ranges, the adjustment rod is lengthened, and an 'inward' short-
ening of the swivel ranges (towards each other), the air lever is shortened.
The basic setting shown in image 8 allows for symmetrical swiveling in A0 and B0 in both directions.
The following images show the various adjustments of the swiveling ranges and their effects on the gas
throughput at the gas damper.
In other setting options it will be assumed that
a) the opening progression is from MIN to MAX.
b) The gas throughput at MIN and MAX was preset.
c) The air settings at MIN (air damper mostly closed) and MAX (air damper mostly opened) has been
aligned by way of the air pre-throttling.
The tasks described in a) to c) can be carried out prior to an alignment of the intermediate settings, just like
in two-stage gas burners. In two-stage burners, intermediate settings are not of crucial importance.
The air damper is moved directly by the servomotor, and is seen as a drive in itself.
The swivel movements of the gas damper can be corrected (i.e. adjusted) in the intermediate settings be-
tween MIN and MAX in four procedures. These are listed below in the order of action, but not all procedures
are mandatory.
1) Shifting of the swivel range of the gas damper forward in clockwise direction (inwards) in direction of
the air damper, or backwards in counter-clockwise direction (outwards), away from the air damper.
2) Shifting of the swivel range of the air damper outwards (away from the gas damper) in clockwise direc-
tion, or inwards (towards the gas damper) in anti-clockwise direction.
3) In line with this adjustment - where only one swivel range is adjusted - the adjustment rod will have to
be shortened or lengthened. This adjustment will not be necessary if
4) both swivel ranges
1 and
2 are moved in the same direction.
Fig. 12-10 Gas damper CO
2
curve
1
Hole
NOTICE:
When swiveling open by 10°, a 'hole' in CO
2
content can occur from the MIN position onwards. This is
caused by the sudden change of the air damper setting from an almost sealed MIN position, and by the
