Viadrus GRAND G 36, Manual For Operation And Installation

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5
Pressure loss & flow diagram
0
1000
2000
3000
4000
5000
6000
7000
8000
0 0,1 0,2 0,3 0,4 0,5 0,6
Q [dm
3
/s]
p
z
[
P
a
]
3 č lánky
4 č lánky
5
č
lánk
ů
6 č lánk ů
7 č lánk ů
4. Boiler description
4.1 Boiler construction
The cast-iron sectional boiler drum made of grey cast iron according to:
Č
SN 42 2420 - „Cast iron 42 2420 with laminated graphite“ is the main part of the boiler.
The boiler construction corresponds to the strength requirements according to:
EN 297
Gas – fired central heating boilers – Type B
11
and B
11BS
fitted with atmospheric burners of
nominal heat input not exceeding 70 kW
The power output of the boiler is given by a number of sections. Individual sections are interconnected by
means of forced-on insertion pieces and clamped by anchoring screws. By that they create a burning space
with convection area for transfer of heat from the burnt gases to heating water. Inlet and outlet of the heating
water is situated in the back part of the boiler and it is realised by DN 40 pipes that are ended by Js 6/4“
thread. A combined bulb for sensors of the boiler thermostat and thermometer is screwed in the head casting
of the left edge section. A return valve of the thermal manometer is placed in the head casting of the right
edge section.
A built-in draft damper with a demountable cleaning cover and a neck for putting a stack on are connected to
the top part of the boiler body by means of screws. A safety piece of return flow of burnt gases is assembled
in the left side part of the draft damper. It closes fuel input to the boiler by means of the draft damper in a
case of a problem with exhaust of the burnt gases.
The boiler body is mounted on a steel base (a base plate of the boiler) that closes the burning space from
bellow. Its part is a covering sheet made of corrosion proof steel, a baffle of secondary air and thermal
insulation.
The atmospheric burner consists of circular perforated burning tubes. It is made of corrosion proof steel.
Small rods are placed at the individual tubes. They significantly decrease creation of nitrogen oxides (NOx).
Gas divider with gas nozzles is welded on the burner plate. Also an igniting burner with igniting electrode, a
thermocouple and mV generator is connected to it.
For the version with SIT valve - gas inlet is realised by DN 15 pipe with a regulation valve of SIT 820 NOVA
mV. Its part is also a piezoelectric ignitor that ignites the igniting burner.
The whole boiler body is insulated by attested mineral insulation that decreases losses caused by transfer of
heat to surroundings.
3 sect.
4 sect.
5 sect.
6 sec