What is a Filter Press?

An industrial filter press is a tool used in separation processes, specifically to separate solids and liquids.

A filter press serves as a liquid and solid separation device.

It comprises five key elements designed to efficiently process large batches of pressurized slurry.

Filtration occurs at the filter cloth, a flexible material securely positioned by its corresponding filter plate

Multiple plates stack within a steel frame, clamped together by the hydraulic system.

This plate stack creates a circuit for the liquid, beginning and ending at the manifold.

How Does It Work?

At the heart of the filter press is the filter cloth which separates liquid filtrate from suspended solid particles. Initially some fine particles may pass through (fig. 1). As larger particles bridge the cloth openings, they form an initial layer that enhances filtration efficiency because of the reduction of effective openings in the filter media (fig. 2). During the feed cycle, solids distribute evenly throughout each chamber, and the solids compact tightly because of the increased pressure (fig. 3).

Dewatered filter cake completely fills each chamber by the end of the filtration cycle. Clamping two filter plates together creates each chamber, with filter cloth encasing the entirety of this cavity. The steel frame aligns and holds the plates which form an interconnected system of chambers, and they each contribute to the overall capacity of the fixed-volume filter press.

Once the liquid makes it beyond the cloth barrier, the plates feature an inner porting system that delivers filtrate to the manifold. Once the even-fill process has concluded, the operator changes the valve configuration on the manifold to end the feed cycle and allow filtrate to exit the press through a single point: the filtrate outlet.

Upon completing the filtration cycle, the follower retracts, and the filter press is ready to be emptied. Clamp the press again to begin a new batch.

Various applications including surface finishing and chemical engineering use filter presses in their workflow. Contact us to learn more about how they can help with your dewatering needs.