Question 106Gas Turbine - Assistant Engineer

The correct answer is D) Dehumidifier. When the main reduction gear lube oil system is secured, the dehumidifier maintains the air within the casing at less than 35 percent relative humidity. This is necessary to prevent condensation and corrosion within the reduction gear casing. The dehumidifier actively removes moisture from the air, keeping the relative humidity low and protecting the internal components. The other options are incorrect because a rehumidifier adds moisture to the air, a precipitator removes particles but not humidity, and a reciprocator is a type of compressor, not a humidity control device.