Filtration of contaminated liquids uses band filter arranged in roll comprising number of rolled up layers of band-like filter material in filter housing

摘要

The filtration of contaminated liquids uses a band filter arranged in a roll (15) comprising a number of rolled up layers of band-like filter material in a filter housing (1). The contaminated liquid fed to the filter housing flows through the roll from the outside toward the inside. Dirt particles accumulate in the outer layers of the roll. At least one outer layer of the roll is unrolled depending on the degree of contamination of the respective layer. Independent claims are also included for the following: (i) a device for carrying out the above process; and (ii) an exchangeable filter cassette used in the device. Preferred Features: The roll is unrolled at intervals in sections whose length depends on the degree of contamination of the outer layers. The degree of contamination and the time of unrolling are determined by measuring the differential pressure between the area of the filter housing on the dirt side and the inner area (14) of the roll on the clean side.