Device for filter-aid-free filtration of medium, comprises a coiled steel wire, which is used as filter and is a flexible-plastic wire with a form-stable, self-supporting cylindrical structure linked up in longitudinal direction

The device for filter-aid-free filtration of medium, comprises a coiled steel wire, which is used as filter and is a flexible-plastic wire with a form-stable, self-supporting cylindrical structure linked up in longitudinal direction, and a collection chamber (60) for filtration of dirt particle. The coiled steel wire is combined with a filter bundle (26). A gap width is evenly variable over the entire length of the coiled steel wire. The coiled steel wire consists of a metal with elastic characteristics. The coiled steel wire has a coil ratio (w) of 5.5:7.5. The device for filter-aid-free filtration of medium, comprises a coiled steel wire, which is used as filter and is a flexible-plastic wire with a form-stable, self-supporting cylindrical structure linked up in longitudinal direction, and a collection chamber (60) for filtration of dirt particle. The coiled steel wire is combined with a filter bundle (26). A gap width is evenly variable over the entire length of the coiled steel wire. The coiled steel wire consists of a metal with elastic characteristics. The coiled steel wire has a coil ratio (w) of 5.5:7.5, where w is defined as the quotient from the average diameter (D) and the maximum radial profile dimension (D). The steel wire has a larger cross section in spiral longitudinal direction than in radial direction. The steel wire has symmetrical conical cross section, a semicircular cross section and a two-edge profile. The gap has a positive conicity in perfusion direction. The initial gap is variable in the range of 0-3 mm. The filter bundle has medium-close connection (28), is enclosed by housing and is inserted into an oil tank (40). The collection chamber is arranged inside and outside of the filter device. A discharge screw is intended for draining the collection chamber. An independent claim is included for a method for filter-aid-free filtration of medium. Es wird eine Filtereinrichtung sowie ein Verfahren zur filterhilfsmittelfreien Filtration von zu filtrierenden Medien vorgestellt, wobei als Filter ein gewendelter Profildraht verwendet wird, der von dem zu filtrierenden Medium in axialer und durch axiale Spalte des gewendelten Profildrahtes hindurch in radialer Richtung durchströmbar ist. Der Profildraht ist ein elastisch-plastischer Draht mit einer formstabilen, selbsttragenden, in Längsrichtung vorgespannten zylindrischen Struktur.