AN INNOVATIVE FILTERING APPARATUS FOR GAS TURBINES

Air contaminants can severely affect the life of gas turbines. Particles that enter the compressor section can interact with the internal surfaces of the machine leading to the modification of the airfoil shapes and surface roughness. Depending on the particle size and chemical composition, thus the working site of the gas turbine, different degradation mechanisms can occur, such as fouling, erosion, and corrosion. All these phenomena implicate performance drops over time and reduce the reliability of the plant. Multistage filtration systems are usually employed to reduce the contamination at the heavy-duty gas turbine inlet. Inertial separators, wet barriers, self-cleaning filters, and media filters work together in the so-called “filter house” to obtain the most appropriate filtration system according to the contamination of the surrounding environment and the contaminant typology. Inertial separators are more effective against bigger particles (>10 µm) while media filters can capture smaller ones (<10 µm). Media filters are commonly installed in the last stages to face the smaller residual particles captured. The continuous exposure to contaminants leads to the increment of the pressure drop and consequently, the media filter replacement is required after having reached a threshold pressure drop. In this work, an innovative particle separator that combines an inertial barrier with a high-voltage electric field is presented. An extensive experimental laboratory-scale campaign is carried out to evaluate the performance of the device against different types of contaminants, particle concentration, and environmental conditions.