A filter press clamps a stack of plates carrying filter cloths and pumps slurry into the resulting chambers under pressure, usually 0.6 to 1.5 MPa. Solids fill each chamber as a cake while filtrate passes through the cloth and out through the plate drainage channels. When chambers are full the press is opened and cakes are discharged one by one.
Why it matters in practice
Filter presses deliver the driest cakes and the clearest filtrates of any common dewatering device, which is why they dominate where cake moisture or filtrate clarity is the product specification. The price is batch operation, high labour on discharge, and cloth maintenance.
How it is measured or specified
Specified by chamber depth of 25 to 40 mm, filtration pressure of 0.6 to 1.5 MPa, cycle time of 20 to 60 minutes and cake dryness of 65 to 80 per cent solids. Those four figures interact: deeper chambers raise throughput per cycle but lengthen the fill and produce a less uniform cake. Cloth selection is set by particle size and chemistry rather than by pressure, and cloth life, not the press itself, is usually what determines maintenance cost.
Calculators that use this
Equipment referenced in this entry
Related terms
Where this appears on this site
Reference entry GL-FILTER-PRESS. Source slug filter-press · segment solid-liquid-separation. Definitions on this page describe engineering practice in hydrometallurgical process design; they are not a substitute for test work on your own material.
Working with Filter Press? Send the feed material, the throughput and the medium — an engineer replies with a preliminary configuration and the sizing reasoning attached.