Abstract: A method for treating wastewater in a wastewater treatment plant includes passing the wastewater passes through a rake system and, thereafter, a sand trap to separate from the wastewater, solids having different particle sizes. A screening device screens the wastewater emerging from the sand trap to yield a primary sludge that fails to pass through the screening device and a suspension passing through the screening device. The suspension is fed to at least one further treatment stage, and the primary sludge is thickened with the aid of at least one thickener. The thickened primary sludge is fed to one or several further treatment stages. Moreover, a wastewater treatment plant for treating wastewater is described.

Abstract: A device for removing floating material from a liquid, especially from sewage, has at least one sieve element shaped like a filter basket, for example, that in a front side has an inlet opening through which liquid can flow into the interior of the sieve element. The device is equipped with a drive so the sieve element can rotate around a rotation axis. A collection device is arranged within the sieve element for collecting the liquid and/or floating material, in which case the collection device is attached to a pumping-out device for the liquid and/or the floating material. A process for removing floating material from a liquid, especially from sewage, uses a sieve device that contains at least one sieve element that may be shaped like a filter basket, for example, and is equipped with a drive so it can rotate around a rotating axis.

Abstract: The invention refers to a filter device for filtering sewage, wherein the filter device has a drum (16) pivoted around a rotation axis (1), wherein the filter device has numerous filter disks (2) running parallel to one another, attached to the drum (16) and that can be made to rotate together with it with the help of a driving device (3), whereby the filter disks (2) have, in each case, filter surfaces (4) running parallel to one another that delimit several hollow spaces (5) arranged in circumferential direction of the respective filter disk (2) and preferably in fluid connection to one another, in which case the hollow spaces (5) are in fluid connection with the drum (6) through one or several inlet openings (6), so that the liquid to be filtered can flow out to the exterior, starting from the interior of the drum (16) through the inlet openings (6) into the hollow spaces (5) and the filtrate can flow from there to the exterior via the filter surfaces (4).

Abstract: A method for transferring heat includes flowing a wastewater through a tank and flowing a fluid through a heat exchanger having an outer surface. The method further includes aerating the wastewater to produce a convective flow, contacting the outer surface of the heat exchanger with the convective flow to exchange heat, and cleaning the outer surface of the heat exchanger with the convective flow. A system for transferring heat includes a tank, a heat exchanger with an outer surface disposed in the tank, and a fluid flowing through the heat exchanger. Wastewater located in the tank flows over the outer surface of the heat exchanger, and a diffusion pipe disposed in the tank provides air into the tank to produce a convective flow in the wastewater.

Abstract: The invention refers to a device for removing screenings from liquid flowing in a channel (1), especially from sewage (2), the device comprising a tilted screening drum (4) being at least partly immersed in the liquid, being drivable around a rotating axis with the help of a drive and having an open face (5) on the inflow side, the device further comprising an extractor for the screenings, preferably in form of a screw conveyor (11) or suction device (17), whereas the extractor is arranged at least partially inside the screening drum (4) and comprises a feeding section for the screenings, preferably in form of a feeding funnel (15), that is arranged inside the screening drum (4). According to the invention, it is suggested for the screening drum (4) to have a folded sieve wall (19).

Abstract: The invention refers to a device for removing floating material from a liquid, especially from sewage (2), with at least one sieve element shaped like a filter basket (4), for example, that in a front side has an inlet opening through which liquid can flow into the interior of the sieve element, and is equipped with a drive so the sieve element can rotate around a rotation axis. The invention suggests arranging a collection device (17) within the sieve element for collecting the liquid and/or floating material, in which case the collection device (17) is attached to a pumping-out device (20) for the liquid and/or the floating material. Another object of the invention is a process for removing floating material from a liquid, especially from sewage (2), in which case a sieve device is used that contains at least one sieve element that can be shaped like a filter basket (4), for example, and is equipped with a drive so it can rotate around a rotating axis.

Abstract: A method for transferring heat includes flowing a wastewater through a tank and flowing a fluid through a heat exchanger having an outer surface. The method further includes aerating the wastewater to produce a convective flow, contacting the outer surface of the heat exchanger with the convective flow to exchange heat, and cleaning the outer surface of the heat exchanger with the convective flow. A system for transferring heat includes a tank, a heat exchanger with an outer surface disposed in the tank, and a fluid flowing through the heat exchanger. Wastewater located in the tank flows over the outer surface of the heat exchanger, and a diffusion pipe disposed in the tank provides air into the tank to produce a convective flow in the wastewater.

Abstract: An apparatus serves for removing fine material to be screened from waste water. The apparatus includes a sieve grate (6) and a detaching device (16). The sieve grate (6) is cylindrical, and it is rotatingly driven. The sieve grate (6) allows for waste water to flow from its interior towards its exterior. The sieve grate (6) includes a supporting body (13) and a mesh sieve (7). The supporting body (13) is located at the exterior of the sieve grate (6). The supporting body (13) is made of a perforated sheet metal including comparatively large openings (37). The supporting body (13) provides for resistance and stability of the sieve grate (6). The mesh sieve (7) is located in the interior of the sieve grate (6). The mesh sieve (7) forms a separation surface (14) for the material to be screened. The mesh sieve (7) includes meshes of a comparatively small size. The mesh sieve (7) is fixedly connected to the supporting body (13). The detaching device (16) is arranged outside of the sieve grate (6).

Abstract: An apparatus for removing material from a liquid flowing through a channel includes a sieve grate, a screw conveyor and a detaching device. The sieve grate has an inflow side, an inner side and an outer side. The sieve grate is designed to be cylindrical and to be rotatably driven. The sieve grate is arranged at an inclined orientation to be partially submerged in the liquid. The sieve grate at the inflow side includes an open face. The sieve grate at the inner side includes a plurality of guide plates. The sieve grate includes a shaping carrier element. The sieve grate includes a mesh fabric, the mesh fabric being designed and arranged to form a separation surface for the material. The screw conveyor includes a housing. The screw conveyor includes a driven conveying screw. The screw conveyor is coaxially arranged with respect to the sieve grate.

Abstract: An apparatus serves for removing fine material to be screened from waste water. The apparatus includes a sieve grate (6) and a detaching device (16). The sieve grate (6) is cylindrical, and it is rotatingly driven. The sieve grate (6) allows for waste water to flow from its interior towards its exterior. The sieve grate (6) includes a supporting body (13) and a mesh sieve (7). The supporting body (13) is located at the exterior of the sieve grate (6). The supporting body (13) is made of a perforated sheet metal including comparatively large openings (37). The supporting body (13) provides for resistance and stability of the sieve grate (6). The mesh sieve (7) is located in the interior of the sieve grate (6). The mesh sieve (7) forms a separation surface (14) for the material to be screened. The mesh sieve (7) includes meshes of a comparatively small size. The mesh sieve (7) is fixedly connected to the supporting body (13). The detaching device (16) is arranged outside of the sieve grate (6).

Abstract: An apparatus for removing material from a liquid flowing through a channel includes a sieve grate, a screw conveyor and a detaching device. The sieve grate has an inflow side, an inner side and an outer side. The sieve grate is designed to be cylindrical and to be rotatably driven. The sieve grate is arranged at an inclined orientation to be partially submerged in the liquid. The sieve grate at the inflow side includes an open face. The sieve grate at the inner side includes a plurality of guide plates. The sieve grate includes a shaping carrier element. The sieve grate includes a mesh fabric, the mesh fabric being designed and arranged to form a separation surface for the material. The screw conveyor includes a housing. The screw conveyor includes a driven conveying screw. The screw conveyor is coaxially arranged with respect to the sieve grate.

Abstract: The invention relates to a device, especially a step rake with stationary and movable blades whose movement enables separation materials to be separated and removed from a liquid flowing through said rake. The lower ends of the blades are arranged in the region of the base of the channel or the base of a body of water and are temporarily raised above the base when they move. In order to prevent sediments from being deposited between the movable blades, a pre-mounted cover is provided in the direction of flow. A collector chamber is provided for sediments underneath the cover. A cleaning device is arranged in the collector chamber in order to remove sediments.

Abstract: A screening apparatus (1) for sewage (13) including liquid (4) and debris and flowing in an oncoming tube (23) includes a conveyor assembly (6) and a separation area (2). The conveyor assembly (6) has a tube-like housing (7), an axle (8) driven by a motor, and a screw (9) provided on the axle (8). The conveyor assembly (6) with its axis (10) is arranged substantially vertical to convey the debris in a substantially upward direction. The separation area (2) of cylindrical shape to deposit the debris has an axis (5), an inner surface (41), a circumference, and openings (3) located about the circumference. The separation area (2) with its axis (5) is arranged in alignment with the substantially vertically arranged axis (10) of the conveyor assembly (6). The separation area (2) is connected to the housing (7) of the conveyor assembly (6), and includes an opening (17) serving as an inlet (40) for the sewage (13) into the interior of the separation area (2).

Abstract: A method for filtering and backwashing solid particles out of liquids is illustrated, with a filter drum (5) positioned completely below the liquid level (6) having a cylindrical surface (7) coated with a filter medium (8), the liquid flown through the outside of the filter drum to the inside. A backwashing device for removal of the filter cake from the filter medium is provided. At the beginning of each cycle of backwashing an air cushion (15) is introduced in the filter drum (5) and liquid in the filter drum (5) is displaced in such a manner so that liquid jets from an ejetion apparatus (19) containing a spraying head (17) and being arranged in the interior of the filter drum without being sealed on the filter drum penetrate through the air cushion (15) to the backside of the cylindrical surface (7) of the filter drum (5). The filter cake so removed from the filter drum is withrawn at the outside of filter drum (5) in a stream of liquid.