DOE to Join with WVU to Lower Costs of Hot Gas Filter Cleaning Systems

Morgantown, WV - One of the keys to future, high efficiency, cleaner coal-fired power plants is the development of hot gas filters. Most of the devices available today to filter pollution-causing impurities from power plant gas streams operate at relatively low temperatures. Tomorrow's advanced power plants - those, for example, that use coal gasifiers and advanced fluidized bed combustors - will require filtering systems that are able to withstand much hotter gas flows and function reliably at lower costs.

In an effort to reduce the operational costs of these future filter systems, the Department of Energy (DOE) and West Virginia University (WVU) will conduct experiments at the university's test facility to better understand how hot-gas filters are cleaned. DOE will provide $232,000 of the total $488,888 project that will ultimately help to optimize the cleaning process.

Advanced coal-fired power generation systems such as pressurized-fluidized bed combustion and integrated gasification combined cycles require coal ash particles to be removed from the gas stream at high temperatures and high pressures before entering the gas turbine. This prevents particles from fouling or eroding turbine blades and other equipment. While significant progress has been made in the past several years, the way filters are cleaned is still not well understood.

WVU's test facility allows a more direct and fundamental understanding of the hot-gas-filter cleaning process. This experimental test system enables researchers to perform in-situ measurements on the filter as it is being cleaned. A special apparatus allows ash to build-up on a filter, so measurements are performed on a realistic ash cake, as opposed to a pressed or reconstituted cake. Then, using a "long distance" microscope and high-speed digital photography, researchers can actually observe the filter as it is being cleaned. A wide range of factors will be assessed to optimize cleaning parameters, such as pulse pressure, pulse duration, pulse frequency, and filter-surface characteristics.

Optimizing the cleaning system will reduce the number of cleaning cycles and compressed gas used to clean filters, thereby lowering costs. Information from this project can be transferred directly to hot gas filter system developers to help them commercialize this technology.

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For more information, contact:
Otis Mills, Jr., DOE Federal Energy Technology Center, 412/386-5890, e-mail: mills@fetc.doe.gov

Technical contact:
Ted McMahon, DOE Federal Energy Technology Center, 304/285-4865, e-mail tmcmah@fetc.doe.gov.