Abstract: An improved method and apparatus for electrocoagulating waste water or fluids to remove colloidal suspensions therein is described. The apparatus includes at least one module having a plurality of closely spaced, flat electrodes defining a plurality of flow paths therebetween. Each pair of electrodes is separately mounted in the module and each electrode has a separate connection to a source of alternating current. Each pair may then be rapidly removed from the module for inspection, maintenance, or replacement or alternate pairs may be removed increasing the distance between the electrodes, if desired. The method allows the utilization of a fluidized bed of graphite particles to scrub the electrode faces, and it also permits the repelling forces on suspended solids to be broken on a continuous basis at relatively low current density in a collapsing field of alternating current.

Abstract: A composite envelope prepared from a multiple panel blank which is folded twice in overlapping relationship to produce a tab portion and a detachable envelope portion. The panels are glued together to form the tab portion and the envelope portion, with a perforation line separating the two. The envelope includes a removable section and a flap containing remoistening glue for sealing the envelope.