INVESTIGATION OF DUST COLLECTION IN A COM BINATION OF FABRIC FILTERS AND ELECTRICAL PRECIPITATORS

To get the advantages of a combination of fabric filters and electrica l precipitators an electric-fabric filter was developed. The dustloade d air stream will be ionized by a discharged electrode. The voltage at the discharged electrode is U=20 kV. The dust collection takes place at a packet of filter layers. Due to the ionization especially small p articles with diameter lower than 1 mu m are much better collected. In this range of particle size the electrostatic forces dominate. The ex periments are carried out with structured and unstructured filter mate rials. The influence of the filtration time, the electrical voltage be tween discharge electrode and filter packet, the air velocity and the number of filter layers to the fractional collection efficiency and pr essure drop are explained. Although the fractional collectional effici ency increases, but the pressure drop decreases. This phenomenon is ex plained using photographs made by an electromicroscope (REM). The dust mass in the filter layers is also given and described.