baltur GI Series Instruction page 26

DIAGRAM OF CONNECTING A BURNER TI THE GAS PIPE NETWORK AT AVERAGE
PRESSURE
E
N
G
L
I
S
H
GENERAL
These are forced-draught burners with gas/air mixtures
at the combustion head. They are suited to working with
forced-draught or low pressure burners according to the work cur-
ves. They bring together great flame stability, total safety and a whole
new level of performance.It is equipped with a steel flange which
slips on the burner head. When fastening the burner to the boiler
it is necessary to correctly position the flange so that the burner
head enters the combustion chamber to the extent specified by
the boiler manufacturer.
DESCRIPTION OF OPERATIONS AT 2-STAGE
PROGRESSIVE
The burner has an electronic cam mod. MPA 22. The micropro-
cessor-controlled MPA 22 provides intermittent operation, controls
and monitors the electronically-modulated fan-equipped gas
burners and features two (air/gas) adjuster motors. When working
as an automatic burner valve seal control is activated; (for a better
understanding of the MPA 22 read the instructions in the attached
manual, code 0006080902).
Operation of is of the progressive two-stage type, so called because
the switch from primary flame to secondary flame (from minimum
to the set maximum) occurs gradually as regards the delivery of
both combustion air and fuel; this gives considerable advantages
in terms of the pressure stability in the gas feed line. Delivery rate
ranges, approximately, from 1 to 1/5. Ignition is preceded by pre-
ventilation of the combustion chamber as per standards, with the
air open: this lasts about 36 seconds. If, at the end of the ventilation
1 - Measuring and reducing unit
2 - Interception
3 - Filter
4 - Reducer
5 - Meter
6 - Wire gauze flame trap
7 - Eventual automatic overflow valve (it should obviously
unload outside in a suitable place)
8 - Emergency interception installed outside
9 - Ball cock
10- Anti-vibration joint
11- A couple of flange
stage, the air pressure switch detects that pressure is sufficient, the
ignition transformer comes on and, after 3 seconds, the safety and
main valves open in sequence. The gas reaches the combustion
head, is mixed with the air being delivered by the fan, and is ignited.
D e l i v e r y i s r e g u l a t e d b y t h e g a s t h r o t t l e v a l v e .
Three seconds after the (main and safety) valves are opened the
ignition transformer is switched off. The burner is now on at the igni-
tion point (P0). The flame is detected by the relative control device
(an ionisation sensor positioned inside the flame, or a UV photocell).
The programming relay goes beyond the shutdown position and
powers the air/gas delivery regulation servomotors, which go to
minimum (P1). If the 2
– adjusted by a temperature or pressure greater than that in the
boiler) – allow, the air/gas delivery servomotors start running and
cause a gradual increase is the delivery of gas and combustion air
until the maximum flow rates to which the burner has been set have
been reached (point P9).
N.B. Electronic cam MPA 22 controls the burner by
adjusting the combustion air and gas servomotors ac-
cording to a pre-set curve.
The burner remains in the maximum delivery position until the tem-
perature or pressure reaches the limit set for the intervention of the
boiler thermostat (or pressure switch) of the 2
the servomotors regulating gas/air delivery rotate in the opposite
sense of direction. Thus gas delivery and the relative combustion
air are gradually reduced until they reach minimum value. Even
with delivery at a minimum, if the limit (temperature or pressure
at the shut down device (thermostat or pressure switch) has been
regulated is reached, the burner will be brought to a standstill. When
the temperature or pressure drops below the intervention limit set
on the shut down device, the burner will star up again, according
8 / 16
0006081361_200805
N° BT 8531/1
REV.: 15/11/1990
stage boiler thermostat (or pressure switch)
nd
stage and makes
nd