11
The SAS UWT boiler makes up a device of construction adapted to operate
in the upper and lower systems for solid fuels combustion.
Basically the standard fuel for the SAS UWT boilers is a black coal for energetic
applications of the nut grade (see chapter. FUEL p. 7) – the fuel ensures that the
declared power will be obtained. Boiler’s exploitation with standard fuel is run in
the lower combustion system.
Combustion chamber solution with multipoint air distribution system makes it
possible to utilize a black coal of the fine grade as an alternative fuel. Boiler’s
exploitation with such a fuel is run in the upper combustion system.
7.2.1 FIRING UP AND FUNCTIONING OF A BOILER IN THE LOWER
COMBUSTION SYSTEM
Before the fire up, smoke throttle in the smoke conduit should be fully
opened, as well as ash box and furnace door, likewise the fuel charge door
which should be fully closed. The operation should be performed slowly, using
crimpled pieces of paper and wood. Then thin layer of coal is applied. Once a coal
is glowing, the ash box and furnace door must be closed. Open fuel charge
door and fill the combustion chamber with fuel, close the fuel charge door and
switch on controller. Set the required temperature on the controller.
During fire up process the boiler should be monitored until it gets feeding water
temperature of 45°C. It is important, as varying fuel quality may cause the boiler to
go out. In case of fire in boiler went out during fire up operation a furnace
must be cleaned, boiler’s channel should be ventilated and fire up should start
again.
During the process a smoking or sweating of boiler may occur. Once boiler and
chimney duct get hot, those adverse phenomena should go away.
During normal exploitation of boiler burning, in the lower combustion system,
process is based on periodic
refueling and raking a grate by moving the arm of
mobile grate mechanism (pos. 13
∗
).
Single load of basic fuel is sufficient for 6 hours of boiler operation at rated power.
With lower capacity the period of slow burning (time gap between refueling) may be
elongated to several hours.
When refueling the controller should be switched off, then slowly open
the fuel charge door, introduce another load of fuel, close the door and
switch on the controller again.
∗
Does not apply to boilers of power above 36kW
