A new filter system, combining a fabric filter and electrostatic precipitator for effective pollution control behind cement kilns

A filter system for particulate control has been developed as an air pollution control device that closely integrates electrostatic precipitation (ESP) and fabric filter technologies into a compact, durable, cost-effective device that produces superior filtration results. Its unique configuration promotes a synergy between these two technologies whereby the filter bags are able to operate at high air-to-cloth (A/C) ratios and be cleaned without the typical concern with dust re-entrainment. The filter requires fewer components than other comparable air pollution control technologies, allowing the use of higher performance and very durable components. Components such as filter bags made with a highly efficient expanded polytetrafluoroethylene (ePTFE) membrane, rigid ESP discharge electrodes, and pulse jet cleaning systems form an integral part of the overall performance which results in superior particulate control at costs comparable to currently used technologies. This filter technology is easily adapted to new installations as well as retrofits of existing ESPs. This paper presents details about the design and operation of the filter along with performance data from an operational cement kiln application in Italy and its associated benefits in this market.