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.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 42,098 filed in the name of T. R. Westfall, June 1, 1970, now abandoned, entitled "Up Flow Separator."
A method of feeding material for centrifugation to a continuously operating centrifuge having a conical drum, wherein the stream of material for centrifugation to be fed to the drum is divided up into n sub-flows and the n sub-flows are fed to n axially consecutive annular sections of the drum surface, the sizes of the sub-flows fed to the annular sections per unit of length in the axial direction being in the same ratio as the squares of the average diameters of said annular sections and a centrifuge with a distributor system inside the drum for dividing the material into n sub-flows.
A conical centrifuge with continuous action, comprising a cylindrical housing, ending with a cone and a connection in its bottom end for the removal of the solid phase. Inside this cone there is fixed coaxially a cylinder, ending with a cone and a connection for the removal of the liquid phase, and over said cylinder there is disposed a conical rotor attached to a shaft, supported in a bearing box and connected by means of a belt drive to an electric motor, which is fastened to the cover of the housing. Concentrically with the bearing box there is provided a vertical pipe, in which there ends a connection, and this vertical pipe is connected to the bearing box by means of vertical blades, which are inclined with respect to the radius and to their outer ends there are fastened helical-shaped blades.
