Adisa ADI CD 375, Техническое руководство по установке, использованию и обслуживанию

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ADI CD boiler - Technical Manual
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17.5 Draining of the boiler condensate
17.5.1 Water condensing
The heat exchanger being in stainless steel, the ADI CD boiler has no limit of the minimum return temperature. This
allows obtaining a higher profit of the heat generated by the combustion products:
- Sensible heat: the heat transferred due to the cooling of burnt gases.
- Latent heat: the heat transferred due to the energy issuing from the water steam when it condenses and
turns into liquid.
The energy efficiency added thanks to the use of the latent heat of the condensate can be up to 11% in case of
natural gas, which is the relation between the High Calorific Value (HCV) and the Low Calorific Value (LCV).
The theoretical volume of the condensate can be:
- 1.63 kg / m3
- up to 0.14 kg / kWh
17.5.2 Condensate neutralization treatment
For natural gas, the condensed water has a pH value that can be between 3.5 and 5.5.
It is recommended to carry out a condensate neutralization treatment before throwing them to the general drainage of
the building, or similar.
Generally, you have to make the condensate circulate mixed with a sort of powder, which can be calcium carbonate,
hydrolyte of magnesium (salt formed by calcium hydride, CaH2, and magnesium) or similar, in order to neutralize
them, which means to increase the value of its pH so that it will be between 6.5 and 9.
It is recommended to take periodical measurements of the water pH after the neutralization treatment: when the value
measured is lower than 6.5 it is recommended to replenish with the powder.
In any case, the neutralization treatment must be made in conformity with the local, autonomic and national laws.
The neutralization system should be placed at a level of height lower than the boiler condensate drain pipe. If this is
not possible, consider the installation of a condensate pump.
17.5.3 Condensate drainage
- The boiler condensate drain pipe should be connected to a siphon.
(Fill the siphon with clean water before starting the boiler).
- Some boiler models should be placed on a base with sufficient height to allow the installation of the condensate
drain pipe, of the siphon and of the connection to the condensate neutralization system.
- The evacuation of the condensate to the general drainage should be made in a visible way, through a visible
connection, open funnel or similar.
- Due to the characteristics of the condensed water, the material of the piping must be resistant to the action of acid
water, for example: plastics (P.V.C).
- The evacuation pipe must have a minimum slope of 30 mm/metre.
- Drainage by means of an external piping is not recommended, due to the risks of condensation and corrosion.
17.5.4 Boiler chimney
The chimney must be made with materials that are resistant to condensed water, which is acid.
The gaskets joining the components of the chimney must be watertight.
The chimney must comply with the national and European regulations.