Abstract: It is disclosed a filtering device (100, 200, 300) that comprises a conduit (10) comprising an inlet (30) and an outlet (20). The filtering device also comprises a filter module (90) comprising a tubular filter (40) having a first end (40a) and a second end (40b), the first end (40a) being open, and the second end (40b) being sealed. The filter module (90) comprises a suction tube (60) arranged to extend inside of the tubular filter (40) between the first end (40a) and the second end (40b). The extending of the suction tube (60) inside of the tubular filter (40) being such that there is an intermediate space (80) between the tubular filter (40) and the suction tube (60) that is fluidly connected to the inlet (30) of the conduit (10) via the suction tube (60). A reaction vessel and a method for manufacturing an aqueous slurry are also disclosed.