baltur COMIST 180 Instructions Manual page 46

4) With the first flame burner running, adjust, if necessary, combustion air delivery.
When regulation is over, stop the burner and start it again for being sure that starting is correct. For getting a mild
starting, remember that you normally need to regulate air to the bare minimum. If starting takes place mildly,
disconnect the burner and connect the second flame thermostat terminals directly (bridge).
5) Set the combustion air regulator in the position you presumably need for adding the second flame (see
BT 8653/1).
6) Now connect the burner again, it will begin to run with first and second flames.
Act on the second flame air-regulating cam for adjusting air delivery according to specific conditions.
7) The burner is equipped with a device which optimizes combustion by decreasing or increasing the air flow
between disk and head. Normally, you need to decrease the air flow between disk and head when the burner is
running with limited fuel delivery, this air way must be proportionally larger when the burner is working with
increased fuel delivery.
If the combustion head is pushed forward (narrower way between disk and head) you must avoid complete
closure. While adjusting the combustion head, you must center the head to the disk perfectly.
Remember that imperfect centering of the combustion head to the disk may result in bad combustion and
overheating of the head with its subsequent rapid deterioration.
Check centering by looking through the inspection hole placed on the back part of the burner, then, tighten firmly
the two screws fastening the combustion head in its position.
8) The maximum rate of smoke allowed is n° 2 of Bacharach scale with a carbon dioxide value (CO
10 to 13%.
GAS (METHANE) STARTING AND REGULATION
N.B. See last pages for specific description of the operations necessary for regulating gas delivery according to the
type of valve applied to the burner.
1) If you did not do it while connecting the burner to the gas pipe, blow off the air contained in the gas pipe.
Do it carefully and with open doors and windows.
Open the pipe fitting close to the burner and, then turn on the gas cut-off cock (or cocks) slightly. Wait until you
notice the typical smell of gas and then turn off the cock.
Wait for a certain period of time, depending on specific conditions, until the gas in the room is dispersed outside
and, then, connect again the burner to the gas pipe.
2) Be sure there is water in the boiler and the equipment gates are open.
3) Be sure that combustion products can be blown off freely (boiler and flue dampers must be open).
4) Turn on the combustion air regulator by the amount you presumably need (see BT 8653/1) and open the air way
between head and disk by one third (see BT 8608/1).
5) Operate on "first flame" and safety valve built-in regulators so as to supply the amount of gas (flow rate on
starting) you presumably need.
N.B. See last pages for specific description of the operations necessary for regulating gas delivery according to
the type of valve applied to the burner.
6) Disconnect the second flame thermostat and give current to the burner by turning on the main switch and the
burner switch (gas position). The burner is therefore connected and carries out the preventilation phase.
If the air pressure control device detects that pressure is higher than the regulated value, the starting transformer
will be turned on, followed by gas valves (safety and first flame valves). Valves are turned on completely and gas
delivery is limited by the position in which the flow regulator built in the (pilot) first flame valve has been set by
hand.
First starting could be followed by "stopping" in service due to poor air purging from gas pipes: in this case gas
supply is not enough for a stable flame.
"Stopping" with flame could also be caused by instability of the flame due to a wrong air/gas ratio. This can be
solved by changing the amount of air and/or gas supplied so as to find the right ratio. This problem could also
be caused by a wrong air/gas distribution in the combustion head. You can solve it by acting on the combustion
head adjusting device by closing (pushing forward) or opening (pulling backward) more the air way between head
and flame disk.
7) With the burner running, adjust delivery to the desired value for "first flame" (methane = 8550 kcal/m
it on the meter.
This rate of flow can be changed by adjusting the valve built-in regulator, as described above.
8) Be sure that combustion is being carried out correctly by checking the relative instruments.
Maximum carbon oxide (CO) allowed = 0,1 % with carbon dioxide value (CO
45
) ranging from
2
3 ) by reading
) ranging from 8 to 10%.
2