can only be practiced successfully with crucible furnaces to a limited extent, and
only with great effort, depending on the system configuration.
As a rule, the temperature range of the cooling water lies between 30 and 65 °C,
with a temperature difference of 27 K. Heating pumps work efficiently at
approx. 80 °C. Above 72 °C, the limescale precipitates out of the cooling water,
the water lines become clogged, and the water has to be treated accordingly.
Practical applications include:
Treatment of washing water and heating of rooms in winter. With a 5-t furnace with 3,000 kW, a maximum of 900 kW of heat energy will be absorbed by the cooling water, which can only be used economically to a very small extent. There is a large number of engineering companies involved in the field of heat recov- ery.