Air heaters and air pre-heaters
Individual concepts for sophisticated areas of application
To reduce exhaust air pollution, air pre-heaters are usually equipped with bare tubes.
Bare tubes can be cleaned more easily, and particles do not attach as easily to bare tubes as they do to finned tubes.
Usually, an air pre-heater has a multi-stage design, consisting of several individual heat exchanger bundles connected in series on the air side.
The first stage is often a water or condensate powered heat exchanger.
A steam-powered low-pressure heat exchanger is connected to this at the second stage.
The third and fourth stages are generally steam-powered heat exchangers with higher steam pressure.
Intermediate ducts are usually installed between the individual heat exchanger stages to allow cleaning of the exchanger surfaces.
Air pre-heaters are used in waste incineration plants or in other areas of power plant technology.
These do operate in exactly the same way as air pre-heaters,
but they tend to be used more in drying technology which heats up cleaned fresh air or recirculation air.
They are therefore generally equipped with finned tubes, which means that recirculation or circulation air heaters in particular must be constructed in a very compact and space-saving way.
Mineral or synthetic thermal oils, saturated steam or water are used as heating media for air heaters.
In addition, air heaters designed as insertion elements can be dismantled very quickly and simply for cleaning purposes.
This type of construction means the time it takes to service the system is reduced to a minimum.