A process for the preparation of a concentrated filter cake from an admixture of partially-decomposed organic material and a polar liquid using a filter press without the input of thermal heat or superheated steam or other pressurized gas or liquid is provided by this invention. The admixture is mixed with an additional amount of the polar liquid to produce a feed slurry of the admixture having a moisture content of about 90-99% wt. The resulting slurry admixture is then introduced into the filter press having a plurality of filter plates with porous membranes secured along their outlet. The pressure condition introduced inside the filter plate chambers is increased by a pressurized gas or liquid to force the polar liquid from the admixture slurry though apertures contained in the membrane, thereby leaving a filter cake of the partially-decomposed organic material having a moisture content that is lower than the moisture content of the initial partially-decomposed organic material feed. The process and its equipment may be used to treat a variety of partially-decomposed organic material/polar liquid slurry admixtures, including high moisture peat containing water, and reduce the moisture content of the resulting peat filter cake to as low as 60% wt for peat or about 50% wt for a peat/Biochar admixture.

For sewage sludge reduction, an apparatus includes a front-end auxiliary filter plate, a back-end auxiliary filter plate, and a plurality of filter plate modules disposed between the front-end auxiliary filter plate and the back-end auxiliary filter plate. Each filter plate module includes a middle main filter plate, a middle auxiliary filter plate, and a plurality of electromagnetic modules comprising an electromagnetic coil wound around an electromagnetic core. The middle main filter plate and the middle auxiliary filter plate are disposed at opposite sides of the electromagnetic modules. An electric current is applied to the electromagnetic coil, attracting the middle auxiliary filter plates and the main filter plates and applying pressure to the sewage sludge.

A recess plate designed for use in a filter device for filtering a suspension includes a stationary head piece and a movable end piece, and a pack including copies of the recess plate, having a filter chamber inside the pack, adjoining the recess plate, having a first pipe for filling the suspension into the filter chamber, having a filter cloth for collecting a solid content out of the suspension, and having a second pipe for discharging a liquid fraction of the suspension out of the filter chamber as a filtrate, wherein the filter device may be closed before filtering by forcing the end piece in direction of the head piece, and opened after filtering by releasing the end piece, and moving the end piece away from the head piece for removing the filter cake from the filter cloth.

A horizontal pressure filter including a washing liquid recovery channel for receiving unused washing liquid from the washing liquid inlet channel and conducting said unused washing liquid to a washing liquid recovery outlet. A flow controller arranged to selectively open and close a flow connection between the washing liquid inlet channel and the washing liquid recovery channel, and respectively, between a compressed gas inlet and the washing liquid inlet channel, such that a gas flow from the compressed gas inlet to the washing liquid recovery channel via the washing liquid inlet channel may be induced, so as to flush unused washing liquid remaining in the washing liquid inlet channel to the washing liquid recovery outlet.

A method for air drying a filter cake contained in a filter chamber defined by a first filter plate, which comprises an air inlet for supplying drying air into the filter chamber to expel fluids from the filter cake, and a second filter plate, which comprises a fluid outlet for discharging fluids from the filter chamber. The method comprises throttling the air flow into the filter chamber by means of an orifice plate that acts as a flow resistance connected in series with the flow resistance of the filter chamber. Preferably the orifice of the orifice plate is so sized that, in case the flow resistance of the filter chamber falls below a normal level, choked flow is achieved in the orifice.

A filter (20) configured to separate the solid components and the liquid components from a slurry. The filter (20) includes a plurality of filter plate assemblies (46) that cooperate to define a plurality of filter chambers (70), each defining a perimeter (96) having an open section (98) when the filter plates (68) are in a closed position relative to one another. Each filter plate assembly (46) includes a closure (104) configured to close the open section (98). Preferably, the closures (104) are movable to an open position to permit a particulate cake to be removed from the filter chambers (70) without separating the filter plates (68).

For sewage sludge reduction, an apparatus includes a front-end auxiliary filter plate, a back-end auxiliary filter plate, and a plurality of filter plate modules disposed between the front-end auxiliary filter plate and the back-end auxiliary filter plate. Each filter plate module includes a middle main filter plate, a middle auxiliary filter plate, and a plurality of electromagnetic modules comprising an electromagnetic coil wound around an electromagnetic core. The middle main filter plate and the middle auxiliary filter plate are disposed at opposite sides of the electromagnetic modules. An electric current is applied to the electromagnetic coil, attracting the middle auxiliary filter plates and the main filter plates and applying pressure to the sewage sludge.

Sludge dewatering device that makes it possible to achieve a high degree of dryness while retaining a limited energy consumption and limited industrial risks, comprising at least one first plate (21a) equipped with a first electrode (23a), and at least one second plate (21b) equipped with a second electrode (23b), wherein the first and second plates (21a, 21b) define a chamber (22) configured for receiving a sludge to be dewatered (10a), wherein the first and second electrodes (23a, 23b) are configured for establishing an electric field within the chamber (22),

wherein the chamber (22) is equipped with at least one discharge port (32, 34), provided in the bottom third of the chamber (22), configured for discharging a filtrate (15a, 16a), and wherein the chamber (22) is equipped with at least one injection port (33), provided in the top third of the chamber (22), configured for injecting the pressurized purge fluid (11a) into the chamber (22).

A filter (20) configured to separate the solid components and the liquid components from a slurry. The filter (20) includes a plurality of filter plate assemblies (46) that cooperate to define a plurality of filter chambers (70), each defining a perimeter (96) having an open section (98) when the filter plates (68) are in a closed position relative to one another. Each filter plate assembly (46) includes a closure (104) configured to close the open section (98). Preferably, the closures (104) are movable to an open position to permit a particulate cake to be removed from the filter chambers (70) without separating the filter plates (68).

A filtration apparatus that can include a filtering device can be configured as a pressure filter. The filter device can facilitate rapid cycling of cake discharge so that the cake formation and discharge sequence can complete itself in a short period of time (e.g. a few seconds, no more than 30 seconds, no more than 10 seconds, up to 18 seconds, less than a minute, less than 3 minutes, etc.).