Dramatic Reduction Of Gas Turbine Fouling With Hepa Composite Membrane Air Intake Filters

Abstract

Gas turbines are protected by air inlet filters that remove particulate contaminants to prevent blade fouling and erosion. The most common filters used today are medium grade filters, which are insufficient to capture submicron particles that cause fouling and performance loss. This leads to reduced productivity, profits and reliability of gas turbines. This paper presents a newly developed filter made with hydrophobic expanded-polytetrafluoroethylene (ePTFE) membrane. The filter offers high efficiency particulate arrestor (HEPA) efficiency with ability to block water and salt penetration. The multilayered media significantly improves the capture efficiency of submicron particles, without the burden of high pressure loss and short filter lifetime typically associated with high efficiency filters. A full-scale study was conducted to evaluate the performance of HEPA composite membrane filters. The new filters were installed at an oil refinery site equipped with two gas turbines form July 2008 to June 2010. The results showed that the HEPA membrane composite filters dramatically reduced fouling and resulted in no noticeable performance loss of the gas turbine over 22.5 months. Filters returned for analysis after 11 months showed only 0.2 inwg increase in pressure loss, indicating that the filters can easily achieve two years or more service in this oil refinery environment.