Anti-Icing Systems

During winter operation of gas turbines or compressors, certain ambient conditions of temperature and moisture can lead to icing in the air-intake system.

Icing can take place when the temperature falls below +5°C and the relative humidity is greater than 70%. The beginning of icing in the filters makes itself apparent by a sudden increase in the pressure difference.

Icing can damage the intake filters as well as other equipment in the air-intake system. To prevent such damage, we recommend warming of the intake air, by means of one of the following anti-icing systems:

Adding warm air from the compressor
In this solution for anti-icing, part of the air is removed from one of the final compressor stages and fed to the mixing battery installed in the intake opening of the filter system. A pressure-reduction station is required here, including a silencer, in order to satisfy noise-suppression requirements

Adding package-exhaust air
Package-exhaust air temperatures are considerably lower than those achieved when adding warm air from the compressor. This signifies that the planning engineer must determine whether the air volume is actually available that is required for achieving the required temperature increase.

Heating of intake air by steam or hot-water-operated heat exchangers
If steam or hot water is available in the plant, their heat can be sent to heat exchangers to warm the intake air. Since control systems with steam are highly complex, investment-cost aspects dictate that preference be given to heat exchangers with hot water.

Infrared filter heating system
Targeted heating of the exposed filters by infrared heating lamps. An efficient and cost-effective solution – but not suited for use in explosion-endangered areas.

Selection of the anti-icing system
When selecting an anti-icing system, it is necessary to consider the geographical location of the system, as well as the expected number of days per year during which weather records would predict the occurrence of icing danger. The following table includes additional factors for this choice.