Abstract: The present invention relates to a process for producing fiber aggregate which includes an orientation step of placing the dielectric fluid containing fibers in the form of short fiber, whisker, or a mixture thereof dispersed therein in a space between a pair of electrodes across which an AC voltage is applied, whereby causing individual fibers in the dielectric fluid to electrostatically orient, with one end pointing to one of electrodes and the other end pointing to the other electrode; and an aggregating step of aggregating the electrostatically oriented fibers while keeping the oriented step, whereby producing fiber aggregate in which the fibers are substantially one-dimensionally oriented.

Abstract: This electrostatic filter dust collector has a dust collecting section which is assembled by using a mini-plate type filter member having a small width of the fold thereof and a short distance between the adjacent ridge portions thereof. Since a plurality of insulating spacers are inserted at suitable intervals into the filter member from the upstream and downstream sides thereof, the percentage of the contacting area of the spacers with respect to the filter member is low, and the percentage of the dust collecting area thereof is high. Electrodes are provided on the upstream and downstream ridge portions of the filter member, and a high voltage is applied between these electrodes, so that a uniform and stable electric field is generated on the filter member as a whole. This enables a high dust collecting efficiency to be obtained.

Abstract: A high-efficiency electrostatic air filter device having high dust collecting efficiency and a long service life is provided. The device is composed of a charging section for electrically charging the dust particles in a gas to be treated, and a dust collecting section provided with a filter medium meandering in the direction orthogonal to the direction of passage of the gas to be treated, a plurality of separator electrodes disposed in the spaces between every adjoining part of said meandering filter medium with or without the medium of insulating spacers from both upstream side and downstream side of said filter medium, and electroconductive elements provided for effectively supplying a high DC voltage between said separator electrodes.

Abstract: In a pulse power source for applying a pulse voltage to a capacitive load; a series resonance circuit capable of generating transient oscillation is formed of the capacitive load adapted to be applied with the pulse voltage, an inductance for generating transient oscillation and a power source capacitor; the capacitive load is charged from the power source capacitor by first closing one of two switch elements provided in the midway of the resonance circuit, that is, a load charging switch element to make the voltage across said capacitive load rise up to about twice the voltage across the power source capacitor after a period equal to about 1/2 of a transient oscillation period of said series resonance circuit, to form a rising edge of the desired pulse voltage; then reversely, the power source capacitor is charged from the capacitive load by closing the other switch element, that is, a charge recovering switch element after first said one switch element has been closed to make the voltage across said capacit