80
Start-up Heavy Oil
Checking Procedure
Function of the steplessly
controlling heavy oil burner
The pumpable heavy oil is supplied to
the high-pressure pump by an oil pump
via ring line, gas-air separator and ser-
vice tank.
The high-pressure pump circulates the
heavy oil through the preheater, pres-
sure control valve and flushing valve of
the oil control block. In this process the
oil is heated up and brought to atomi-
zing viscosity (approx. 12 to 15 cSt).
The flushing valve will be closed after
the preset oil temperature has been
reached.
The pressure control valve installed
downstream of the high-pressure bur-
ner pump will keep the oil pressure at
the constant level of 28-30 bar in accor-
dance with an overflow principle.
The nozzle rod assembly has 2 connec-
tions, the oil feed and the oil return con-
nections. Two types of nozzle rods can
optionally be used, i.e. the DG75 and
the MAT nozzle rods.
If the DG75 nozzle rod is used, the sole-
noid valves will be opened in the feed
and return lines for approx. 45 seconds
prior to fuel feed start. A flushing pro-
cess is started via the nozzle rod and
output controller so as to ensure the
required fuel oil temperature also imme-
diately upstream of the nozzle.
A flushing operation is not used with
burners having the MAT nozzle rod. In
this case the required viscosity is achie-
ved by heating the nozzle rod.
After the solenoid valves or nozzle
needle have opened, the oil pressure
will be controlled via an oil controller in
the return line (minimum pressure
approx. 3-5 bar; maximum pressure
approx. 16-18 bar).
If the compound controller is increased
to maximum output, the oil pressure will
be brought to approx. 16-18 bar (maxi-
mum output of nozzle). This output
must correspond to the rated output of
the heat generator as shown in the
nozzle output diagram.
Simultaneously with the oil flow rate
control, the air flow rate control cam of
the compound control system will con-
trol the air flow rate required for the
combustion of the oil quantity supplied.
Check the following prior to the
initial operation of the boiler system:
- Take care to observe the operating
instructions supplied by the boiler
manufacturer. The boiler must be
mounted ready for operation.
- Ensure that the heating system is filled
with water.
- Check the complete system for correct
electrical wiring.
- Check the air fan and pump motor for
correct direction of rotation.
- For checking the direction of rotation
of the air fan and pump motors (direct
connection) shortly actuate or press
the contactor.
In star-delta connection layouts it will
be necessary to actuate the mains and
star contactors at the same time.
Check the correct direction of rotation
of the oil pump by comparison with the
direction-of-rotation arrow stamped to
the pump.
- Check for the proper setting of the
temperature and pressure controllers,
limiters, safety switches and electrical
limit switches.
- Bleed the fuel carrying lines, pumps
and pre-heaters (make sure no air is
contained).
- Check that the tank, lines and oil pump
are filled with oil and that the proper oil
nozzle has been fitted.
- Make a test of the hydraulic oil system
for absence of leaks.
- Check the exhaust gas ports are ope-
ned and sufficient fresh air is taken in.
- With the burner in starting position
check that air damper is closed.
- Check that the automatic furnace con-
troller is unlocked and in its original
position.
Oil start-up
- Open all stop valves of the oil supply
system; fill pumps with oil.
- Install feed pressure gauges, vacuum
gauges, pumps, etc.
- If a ring line is provided fill this with oil
and take it into operation. Check oil
temperature (min. 50-60°C depending
on viscosity).
NOTE:
The hydraulic system is factory-
filled with test oil which might lead to
ignition trouble during initial start-up. To
protect the pump the oil pressure con-
troller is factory-set at a low pressure
only. When starting the burner make
sure to increase the oil pressure to ope-
rating level gradually.
Prior to initial fuel feed start make a
functional test of the burner program
flow.
Disconnect the lifting magnet of the
nozzle needle valve (solenoid valve) by
reference to the wiring diagram.
Start the burner and check the program
flow for correct sequence of start-up
operations.
1.
Flushing (oil temperature).
2.
Fan.
3.
Air damper pre-ventilation (check
limit switch setting).
4.
Check air pressure.
5.
Air damper starting load (check
limit switch setting).
6.
Ignition (ignition gas valves).
7.
Fuel valves.
8.
Shutdown on trouble after safety
time has run down (see automatic
furnace controller).
9.
Unlock automatic furnace control-
ler.
