Hydraulic filter presses are widely used for industrial dewatering applications across various sectors. They employ hydraulic force to compress filter plates or frames, separating liquids from suspended solids in slurries and sludges.

plate and frame filter press

How Hydraulic Filter Presses Work?

A hydraulic filter press consists of a series of filter plates or frames stacked together. The plates or frames contain a filter medium like cloth or membranes.

When a slurry or sludge enters the press, high pressure hydraulic fluid is pumped into cylinders that force the plates or frames together. This action compresses the filter media, squeezing liquid out while capturing solids.

After a set period of time, the hydraulic pressure is released and the dewatered solids discharge from the press. Fresh feed then enters the chambers and the cycle repeats continuously.

Types of Hydraulic Filter Presses

There are two main types of hydraulic filter presses:

Frame filter press – These use filter frames that are bolted together. They feature easier cleaning and plate replacement but generally produce lower cake solids content under 25%. Frame presses also require more floor space.

Plate filter presses – These consist of filter plates separated by spacers. They offer rapid discharge, high cake solids content up to 30-35% and require less floor space. However, the plates must be removed for cleaning.

Both plate and frame hydraulic filter presses are available in manual, semiautomatic or fully automatic models with programmable logic controllers.

Advantages of Hydraulic Filter Presses

  • Produce high cake solids content from various feed slurries and sludges
  • Provide gentler pressing action that reduces solids damage
  • Offer simple and robust design with few moving parts
  • Require minimal maintenance and downtime
  • Enable flexible operation for batch or continuous filtration

Uses of Hydraulic Filter Presses

  • Mineral processing – To dewater mineral slurries from operations like flotation, thickening and classification
  • Chemical production – For filtering and recovering valuable chemicals from wastewater and byproducts
  • Food processing – To remove water from products like fruit pulps, juices and wine slurries
  • Wastewater treatment – As part of sludge dewatering in municipal and industrial plants
  • Pharmaceuticals – For recovering and concentrating active ingredients and valuable byproducts