A type of continuous filter used to remove bulk liquid from a suspension of particles such as a precipitate to produce a wet filter cake (see Fig. 53). It consists of a perforated circular plate that slowly rotates. Material is fed onto a point on the plate that (p. 333) rotates over a plenum operating at a reduced pressure drawing the liquid through the plate. The remaining filter cake is continuously scraped from the surface.

Fig. 53 Rotary drum filter