DESCRIZIONE
The filter device (2) has a filter chamber (6) which surrounds the housing (4). A cleaning device attached with filter belt (8) is provided for removing retained particles (P) using sprays. The filter belt is driven by a drive device (14) such that the driving force (F) is generated by pseudo-continuous driving movement of the filter belt when the reference level (Pref) of the dirty water region (12) exceeds continuously. The drive device is connected to a control assembly so as to activate the cleaning device in response to driving movement.