5
3. Description
3.1 Construction of the furnace
The main part of the furnace is the cast iron section boiler drum made of grey cast iron according to:
Č
SN 42 2415 Grey iron 42 2415 with luminated graphite, or
Č
SN 42 2420 Grey iron 42 2420 with luminated graphite
Pressure parts of the furnace correspond to the demands on solidity according to:
Č
SN 07 0240 Warm-water and law-pressure steam boilers
Č
SN 07 0245 Warm-water and law-pressure steam boilers. Warm-water boilers up to 50 kW output.
The boiler drum consists of sections with the help of pressured boiler nipples and is secured with boiler
screws. The sections create burning and ash space, water space and a convective part. Heat water input
and output are situated at the back part of the furnace.
The back section of the furnace has a smoky chimney – pot and a heat water flange in the upper part,
and a returnable water flange with a socket for impregnating and clearing plug. Stoker and ash door and a
firebox door under them are fixed to the front section.
The whole boiler drum is isolated with a stifling, mineral isolation that reduces losses by sharing heat into
the surroundings. The steel jacket is fitted in colour with a quality comaxite paint.
At seven to ten – sectional size of the VIADRUS U 22 C furnace two tapes of medium sections are used:
at the front part of the furnace the sections are without a molding and in the back part with a molding. The
molding closes the burning space and carries back the flame and product of consumption from the back
space to the front part of the furnace, i.e. by the back path in smoky draughts it is perfectly taken advantage
of the product of consumption heat.
Number of sections without and with a molding is mentioned in the following chart:
Chart Nr.5 Medium sections of the VIADRUS U 22 C furnace
Size of the furnace in sections
2
3
4
5
6
7
8
9
10
Medium
section
with
a
molding - 1 2 3 4 4 5 5 6
Medium
section
without
a
molding - - - - - 1 1 2 2
At the VIADRUS U 22 D furnace three types of medium sections are used: in the front part of the furnace
(except the four – section size) there is a section with a recess for easier fuel inserting to the average up to
220 mm, then sections without a molding, in the back part with a molding. The molding closes the burning
space and carries back the flame and product of consumption from the back space to the front part of the
furnace, i.e. by the back path in smoky draughts it is perfectly taken advantage of the product of
consumption heat.
Chart Nr. 6 Medium sections of the VIADRUS U 22 D furnace
Size of the furnace in sections
4
5
6
7
8
9
10
Medium
section
with
a
recess
- 1 1 1 1 1 1
Medium
section
with
a
molding 2 2 3 4 5 5 6
Medium section without a molding
-
-
-
-
-
1
1
3.2 Regulating and security elements
The smoky flap of the smoky chimney – pot regulates the climb of the product of consumption from the
furnace to the chimney. It is regulated with the handle with a rod in the upper left part of the furnace next to
the stoker hole.
Stifling of the ash door regulates the inflow of the combustion air under the grate of the furnace. It is
regulated by the draught governor or manually with an adjusting screw of the stifling.
The air rose of the stoker door serves for carrying the secondary air to the burning space. To control the
rose it is necessary with respect to the higher surface temperature of the stoker door to use an instrument
that is part of the delivered tools.
The cleaning cover of the smoky chimney – pot located in its bottom part serves for cleaning the
embedded waste product caused by burning.
There are barriers of the smoky channel between the front and medium sections above the stoker hole
of the furnace VIADRUS U 22 C. It serves for reducing the draw – away cross - section and for a better
