Method of cleaning filter discs in a suction dryer using ultrasonic vibration

Abstract

Method in a suction dryer (10), which comprises a basin (12) for a suspension to be suction-dried, in connection with which basin one or several filter-plate discs (14a) revolve, onto whose faces a filtrate cake is gathered and dewatered by the effect of a suction flow passing through the filter plates (14a), the said filtrate cake/cakes being scraped or otherwise detached from the faces of the filter plates (14a). For the purpose of cleaning the porous structure and faces of the filter plates (14a), an ultrasonic detector or detectors (30) are provided in connection with the basin (12) for the suspension to be filtered, to which detectors an electric power of ultrasonic frequency is fed from an ultrasonic generator (32). For the time of the cleaning intensified by ultrasound, the suspension basin (12) is filled with a connecting and cleaning liquid, e.g. water. The filter-plate discs (14) are rotated in the connecting and cleaning liquid by means of the same equipment (14, 13, 18) by means of which the rotating of the filter-plate discs (14) takes place in connection with the suction drying.

Dependencies are inferred from the claim text.