Abstract: A cleaner has in a tank a vacuum pump protected by a float valve above the maximum possible water level and a submersible pump at the bottom and both of these in the tank produce a vacuum for the suction of water against the vacuum, the submersible pump moving the filtered water collected in the lower region of the tank out of the tank past a check valve. The vacuum pump is constructionally combined with a tank cover, so that it can be mounted on differently constructed tanks for different cleaning functions. For wet suction purposes, the associated paper filter bag has a passage opening for the suction connecting pieces, so that the water to be filtered passes through the filter from the inside to the outside.

Abstract: A filter apparatus, particularly for filtering air containing fumes is provided on the inlet side to an exhaust fan (8), electrostatic filters (36) and a flat test filter (38) immediately following the latter. On the outlet side of the exhaust fan (8) a cartridge filter (3) with a plurality of parallel filter cartridges (26) in the flow path is provided. In the flow path directly upstream of the test filter 38, as well as between outlet (14) and the inlet of cartridge filter (3), the pressure is measured by in each case one pressure indicating device (53, 54). When the electrostatic filter (36) becomes saturated, the contamination relatively rapidly increases the flow resistance of test filter (38), which is indicated by a pressure change between the electrostatic filter (36) and the test filter (38).