filterpresser

A filterpresser, commonly known in English as a filter press, is a machine used for solid–liquid separation in which a slurry is pumped into a series of tightly clamped plates lined with filter media. As liquid passes through the filter cloths, solids form a cake between the plates. When filtration is complete, the plates are separated to discharge the filtered solid cake and the remaining liquid, or filtrate, is collected from the channels.

A typical filterpresser consists of a frame holding multiple plates and frames, each covered with a filter cloth. The plates are pressed together by a hydraulic, pneumatic, or mechanical drive, creating a sequence of filtrate chambers. The slurry is fed into these chambers, filling the gaps between cloths. Filtration reduces the slurry volume as liquid passes through the cloths, while the solid cake becomes progressively drier. In many designs, a membrane or recessed plate option allows additional compression or squeezing to increase cake dryness. After filtration, the cake is discharged by separating the plates, either batchwise or in a controlled manner for intermittent operation.

There are several variants, including chamber filter presses, recessed plate filter presses, and membrane filter presses. They are used in industries such as mining and mineral processing, chemical manufacturing, wastewater treatment, food and beverage, pharmaceutical, and ceramics. Advantages include high solids capture, compatibility with viscous slurries, and strong washing and drying capabilities. Limitations include batch operation with relatively long cycle times, high energy and space requirements, and periodic maintenance of seals and cloths.

Maintenance focuses on filter cloth integrity, plate seals, hydraulic systems, and plate alignment. Proper operation requires monitoring of filtration rate, cake dryness, and filtrate clarity to ensure process efficiency and safety.