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601130040 [Revision 1502.00] [subject to changes with no previous notice]
Biofell Cascade
To preserve the primary circuit heat exchanger and ensure optimum heat transfer, the features of the water flowing through the boiler’s primary condensate
exchanger must remain constant over time. Preparatory work such as the system’s cleaning and maintenance, checking water features, and installing
filtration systems are essential to achieve this goal.
The choice of water treatment should be made according to the water features, the system type, and the limits of purity required.
Oxygen
Inevitably a certain amount of oxygen will infiltrate the system, both in the filling phase and during operation (system refills, or using materials without
oxygen barrier). Oxygen reacts with steel, causing corrosion and sludge formation. The heat exchanger is made of stainless steel to avoid corrosion, but
sludge may accumulate on hot parts, including the exchanger. As a consequence, the boiler’s power is reduced, and the primary exchanger’s active parts
may obstruct, which in turn may damage the boiler.
To limit this consequence one can resort to:
Mechanical systems: a suitable combination of traps and water softener reduces the amount of oxygen present in the system.
Chemical systems: additives that allow oxygen to remain dissolved in water.
Hardness
Depending on the mains water hardness, its calcium content varies. Calcium sticks to hot parts, including the primary heat exchanger. This may reduce the
boiler’s capacity, and obstruct the primary exchanger’s active parts, which can seriously damage the boiler.
If the mains water does not comply with the values shown in the following table, then it must be treated to soften it. Additives can be used to keep the lime
dissolved. Water hardness should be controlled regularly, and the following values recorded:
Acidity
6,6 < pH < 8,5
Conductivity
400 ÷ 600
μ
S/cm (a 25°C)
Chlorides
< 125
mg/l
Iron
< 0,5
mg/l
Copper
< 0,1
mg/l
When the above values are exceeded, applying a chemical treatment is necessary.
Remember that the choice of a water treatment should be made according to the water features, the system type, and the limits of purity
required.
3
Combustion Waste Disposal
3.1
Single Exhaust Pipes
The installation of exhaust ducts for combustion products must be performed by qualified personnel, and must comply with the requirements of the national
and local laws and regulations. The
Biofell
boilers are pressurized, so the evacuation of combustion products is via a sealed 80 mm-diameter outlet duct,
while the air is taken in from the room where the boiler is installed.
All accessories used in the evacuation of combustion products must be supplied by Tifell.
The maximum flue length (L) that can be installed is:
Flue’s maximal length D=80
Models
Maximum length
Biofell 30
15.00 m
Biofell 50
7.00 m
When setting up the flue, one must consider the equivalent lengths of the fittings listed in the following table in any case maximum length be exceeded.
Equivalent lengths of accessories
Accessory
Vertical
Horizontal
1,000 mm linear section
1.00 m
1.50 m
90º bend
1.50 m
2.50 m
45º bend
1.75 m
1.00 m
It is recommended to place the vent pipe slightly inclined (2 to 3 %) upwards, thus preventing its blowing out condensate produced in the duct. Do not turn
the flue more than four times in the whole length of the discharge.
If the flue is completely vertical, and its length greater than 3 m, a condensation-collecting siphon should be connected to a drain on the
duct’s base.
