A method of operating a filter press, wherein filter material is fed into a filter chamber so as to form a filter cake between at least two sides of a flexible said filter medium. Filtrate is received from the filter chamber and the filter cake formed the filter chamber is discharged. Prior to discharging the filter cake, compression is applied on the filter cake formed within the filter chamber by providing compression fluid gas at a compression pressure exceeding a prevailing pressure within the filter chamber, directly on a side of the filter medium exterior to the filter chamber, so as to exert said compression pressure directly on said side of the filter medium, thereby causing the filter medium to yield against the filter cake.

A method of operating a filter press, wherein filter material is fed into a filter chamber so as to form a filter cake between at least two sides of a flexible said filter medium. Filtrate is received from the filter chamber and the filter cake formed the filter chamber is discharged. Prior to discharging the filter cake, compression is applied on the filter cake formed within the filter chamber by providing compression fluid gas at a compression pressure exceeding a prevailing pressure within the filter chamber, directly on a side of the filter medium exterior to the filter chamber, so as to exert said compression pressure directly on said side of the filter medium, thereby causing the filter medium to yield against the filter cake.

The present invention relates to an integrated process for recovering tomato juice from tomato pomace as well as biologically dehydrating and stabilizing it. The innovative process developed involves four main steps: separation by dissolution in an aqueous matrix compatible with human feed, solid-liquid separation, filtration cake washing and thermal dehydration. The tomato juice resulting from the developed process is intended to be incorporated into the tomato concentrates of the tomato: processing industry. The dehydrated tomato pomace is a biologically stable product and can be used in ruminant and non-ruminant animal feed and as raw material for biotechnological and pharmaceutical applications.

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. A plurality of microwave generators send microwaves through microwave acting channels to irradiate the sewage sludge. 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 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 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.

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 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.