To allow heat to be used flexibly, it is often necessary to extract the thermal energy at various temperature levels. Heat recovery systems used with local heat and district heat allow the energy that is recovered to be put to the best possible use in a profitable way. For example:
Economizers and enable heat to be used in two stages; in the first stage, the ECO (economizer) recovers sensible heat on the water side at a temperature of around 100 °C. This energy can be reused between 90 and 100 °C in applications such as district heat, process heat or standard drying plants.
and condensers enable heat to be used in two stages; in the second stage, the RAKO (flue gas condenser) decouples latent heat on the water side at a temperature of around 60 °C. This energy is used for local or district heating networks and for drying shavings, fuel or sawn timber (e.g. in low-temperature drying chambers).
Depluming refers to the process of preventing or reducing the steam plume at a chimney outlet. The steam plume is primarily dependent on the exhaust gas dew point and the operating conditions (temperature, air humidity).
In many cases, the steam plume may not be visible; there are various reasons for this. To meet this requirement, air preheaters are used to perform depluming. For financial reasons, however, this kind of system should be combined with a in all cases.
Mixing the two air flows in the – by means of flue gas cooling or outside air warming – enables the necessary cooling following outlet from the chimney.