Cooling air system, air flow controlled and soundproofed


The body of a 64m long rotary furnace, with a diameter of 4.2 m and an exterior temperature of approx. 500 °c, should be cooled in a controlled manner. The temperature fluctuations throughout the day and throughout the year influence the temperature of the mantle furnace.  The mantle furnace should be able to be kept within certain tolerances at all times, throughout the entire year.  In addition, very specific acoustic limitations must be observed.


Two fans, driven by two frequency controlled motors, generate a pressure of up to 2600Pa and expedite up to 40’000m3 of air per hour per fan. The fan enclosures, as well as air inlet and outlet are sound-proof. The air flows through a pipe system and is blown over the nozzles to the outer casing of the rotary furnace. Each of the eight nozzles has a pneumatically driven flap that can be used to individually regulate the amount of cooling air.

The project was completed to the full satisfaction of the client. The air cooling system was successfully installed and put into operation at the beginning of 2010.