Abstract: In a method of dewatering suspensions or the like slurry-like mixtures, in particular waste water slurries, fed to a belt filter press formed by filter belts, with the waste water slurry, is a crumbly dry substance which has been produced by drying from the solids discharge of the belt filter press.

Abstract: A dewatering device with two filtering belts comprising two endless bands guided over drums and a gap limited by the bands for a heap of debris as pressure product guided through this pressure zone, with a supporting means being allocated to one of the bands on that side looking away from the heap of debris is to be improved concerning its dewatering activity. For this purpose, the supporting means is provided in the form of a supporting plate (20) curved in the driving direction (x), which supports a sieve-like belt or band (13) in the pressure zone and shows break-throughs. The band (13) rests on a gliding plane of the curved and perforated supporting plate (20), the radius of curvature (r) of which decreases towards the driving direction (x). The supporting plate (20) is composed of a flexible material so that its radius of curvature (r) can be adjusted.

Abstract: A process of dewatering sludge in which raw sludge and a flocculating agent are first mixed by suitable means, then fed into a rotary filter drum or similar device to effect thickening of the sludge and partial dewatering thereof. The now thickened sludge is then conveyed through a filtering assembly in which the sludge is subjected to further dewatering forces, which could be vacuum, centrifugal, static pressure, or pressure while moving along the filter surfaces, thereby further dewatering the sludge. The filtrate discharged from the filter drum and the filtering assembly and also wash water used for cleaning the filter surfaces in the filter drum and the filtering assembly are at least partly returned to the filter drum to effect total flocculation and recapture of sludge particles contained in the filtrate and the wash waters.

Abstract: Apparatus for the batch filtration of suspensions comprising a plurality of press-chambers and filter belts for transporting the suspension stepwise through the press-chambers, such that after pressing the suspension in the first press-chamber and before entry of the resultant press cake into at least one subsequent press-chamber, the structure of the press cake is changed by shearing forces and the press cake is curved and at least partially torn apart. In the case of municipal sludge the flaked sludge is subjected in a first pressing zone to slow increase of pressure and a pressure of up to about 1 bar and is subjected in at least one following press zone to a pressure increase which is more rapid than in the first press zone, up to a pressure of about 3 bars.

Abstract: Band filter devices for continuously dewatering a suspension, such as sewage sludge comprising an upper filter band stretched between deflection rolls, the upper strand of which forms a filter zone, and a further filter band which together with the lower part or strand of the first band forms a compressing zone. The filter band is stepped at least once in a Z-shaped manner in the filter zone by providing a further deflection roll which is positioned lower than and downstream of the first deflection roll but in a position counter to the direction of transport, and such that between two filter zones there is a zone where the sludge cake is transferred to another part of the band and rearranged. Above the upper strand or part is at least one ram or beam which lies transverse to the direction of transport and the ram can be pressed into the sludge cake to produce transverse grooves or channels in the sludge cake.

Abstract: For the batch filtration of suspensions by application of external pressure, after the pressing of the suspension in the press-chamber space and before entrance of the resultant press cake into at least one subsequent press-chamber space the structure of the press cake is changed by shearing forces and the press cake is curved and at least partially torn apart. In the case of municipal sludge the flaked sludge is subjected in a first pressing zone to slow increase of pressure and a pressure of up to about 1 bar and then is subjected in at least one following press zone to a pressure increase which is more rapid than in the first press zone, up to a pressure of about 3 bars.

Abstract: There is disclosed a process of dewatering sludge and other materials of that kind. The process provides that the raw sludge and a flocculating agent are first mixed by suitable means, then fed into a rotary filter drum or similar device to effect thickening of the sludge and partial dewatering thereof. The now thickened sludge is then conveyed through a filtering assembly in which the sludge is subjected to further dewatering forces, which could be vacuum, centrifugal, static pressure, or pressure while moving along the filter surfaces, thereby further dewatering the sludge. The filtrate discharged from the filter drum and the second filtering assembly and also wash water used for cleaning the filter surfaces in the filter drum and the second filtering assembly are at least partly returned to the filter drum to effect total flocculation and recapture of sludge particles contained in the filtrate and the wash waters.There is also disclosed an installation for carrying out the dewatering process.

Abstract: There is disclosed a device for dewatering sludge such as residuals in sewage discharge processing installations. The device provides that cakes are formed of the sludge. These cakes have initially a high water content and are of non-homogenous, loose consistency. They are guided between filter bands through a preliminary filtering zone in which some of the water contained in the cakes is extracted by straining and pressure action applied thereto. The filter bands with the cakes therebetween are then successively guided over a first dewatering drum and a subsequent second dewatering drum. Pressure is applied to the filter band while being guided about the drums, thereby extracting further water from the cakes. Additionally, the cakes while traveling from the feed-in point toward and through pressure zones are deformed and also turned over thereby compacting the cakes as water is extracted therefrom. Finally, the cakes after being sufficiently dewatered and compressed are discharged.

Abstract: There is disclosed a device for dewatering sludge, sewage and other materials containing water and solid particles. The device comprises at least two rotatable and two superimposed power driven filter bands which are successively guided to and about the perforated cylindrical walls of the drums in pressure engagement therewith so as to drive the drums in opposite direction and causing release of water from sludge fed between the two filter bands. After leaving the last drum the bands are guided by rolls along a meandering path along which the sludge is repeatedly stretched and pressed to cause further release of water from the sludge and to discharge the now dewaterized sludge at the end of the path.

Abstract: There is disclosed a method of dewatering sludge such as residuals in sewage discharge processing installations. The method provides that cakes are formed of the sludge. These cakes have initially a high water content and are of inhomogenous, loose consistency. They are guided between filter bands through a preliminary filtering zone in which some of the water contained in the cakes is extracted by straining and pressure action applied thereto. The filter bands with the cakes therebetween are then successively guided over a first dewatering drum and a subsequent second dewatering drum. Pressure is applied to the filter band while being guided about the drums, thereby extracting further water from the cakes. Additionally, the cakes while traveling from the feed-in point toward and through pressure zones are deformed and also turned over thereby compacting the cakes as water is extracted therefrom. Finally, the cakes after being sufficiently dewatered and compressed are discharged.