There is disclosed herein a method and system of screening and simultaneously aerating wastewater, such as storm water overflow containing untreated sewage. The method involves one or more high-rate rotating screen concentrators wherein the influent is fed to the interior of a generally cylindrical, rapidly rotating screen. The concentrator is constructed to permit dispersion and atomization of effluent for increasing exposed fluid surface area and for improving contact thereof with air to increase the dissolved and/or entrained oxygen in the effluent. This may be accomplished by allowing a relatively unobstructed fall of the effluent out-wardly into a container, storage tank, treatment or storage lagoon or the like. The dissolved oxygen aids aerobic digestion and the entrained oxygen aids in frothing of the effluent for subsequent floatation and separation of fine solids and oils. The concentrated material which does not pass through the screen may be piped to a treatment facility.

There are disclosed herein equipment and methods for screening and concentrating waste water overflow from combined sewer systems. Exemplary equipment includes a separator employing a substantially cylindrical rotating screen. Influent is piped upwardly into the equipment and deflected outwardly toward the inner surface of the screen in a manner to achieve a desired flow rate and flow pattern of the influent onto the screen. Means are provided for controlling the flow rate and for suitably directing the influent in a plurality of substantially discrete inclined streams toward the inner surface of the rotating screen. The screen is rotated at a speed to achieve a desired centrifugal force. Effluent passes through the screen to an outlet and the remaining concentrate passes to an outlet. The screen is in the form of a screen cage having a plurality of removable screen panels for facilitating replacement of damaged screens or changing of screen type or mesh size. Cleaning means is provided for directing a cleaning fluid periodically at the screen. The methods disclosed involve the manner in which the influent, effluent, concentrate and back-splash are handled, and the manner in which the influent is screened to achieve a fluid concentrate which is pumpable to other treatment equipment for ultimate disposal. Additionally, a sequence of influent feed and screen cleaning is described.

Apparatus for filtering particulate matter in a fluid (e.g., gas) and in particular small particulate matter, the apparatus including a rotating filter, an expander or turbine for extracting energy from the fluid after the fluid has passed through the filter, an aerodynamic seal comprising a rotating multiple fin or vane member which rotates with the filter and expander, and depending upon the type of particulate matter, there is provided a spray system or a scrubbing system to aid in filtering the particulate matter.

A filtration device including a self-propelling rotating filter cage and means to aid in the rotation of the filter cage, said means comprising motor drive means or pressure producing means.

Apparatus for separating solid particles from liquid in a slurry in which radial blades are attached to a rotating base plate. The blades slope in a direction opposite the direction of rotation whereby the trailing edge of the blade is spaced from the base plate. Means are provided for delivering the slurry onto the inner end of the impellers near the surface of the base plate and for rotating the disc. The solid particles move rapidly in a radial direction along the impeller blades. That rapid movement creates a Coreolis force that causes the particles to be discharged from the trailing edge of the blades. Because the liquid wets the blades and the viscosity of the liquid slows movement of the liquid on the blades, Coreolis forces on the liquid are relatively small and the liquid is discharged from the outer end of the blades. The solid particles and liquid are collected separately as they are discharged from the impeller blades.