Skip to main content

The Kadant Blog

Common Pressure Liquid Filter Definitions

When it comes to pressure liquid filters, there are some common terms shared across industries. The following is a list of definitions often used when working with pressure liquid filters.

Backwashing: Cleaning filter media and removing entrapped solids by forcing a flow of liquid in a reverse direction through the media.

Batch Filtration: Filtering a given volume of liquid prior to cleaning a filter stream. The process may be interrupted to clean the filter medium.

Continuous Filtration: All flow is filtered; the filtration process is uninterrupted by media cleaning, replacement, or maintenance.

Cycle Length: Duration, measured in time or gallons/liters, that filter media can operate effectively between cleanings.

External Backwash: Use of a liquid other than that being filtered to backwash the media. This source could be the filtered liquid with boosted pressure.

Filter Medium: A barrier of permeable material that traps solids in flow.

Filtrate: Liquid that has passed through a filter medium.

Internal Backwash: Use of the liquid being filtered to backwash the media.

Media Open Area: Amount of space on a filter medium surface that can be penetrated by a liquid. A prime determinant of solids retaining capacity.

Pressure Differential: Difference in pressure between an entrance flow and an exit flow.

Side Stream Filtration: Taking a portion of a given process stream and filtering the portion before reintroducing it into the mainstream.

Solids: Granular, fibrous, or glutinous material suspended in a liquid which can be removed by the mechanical process of filtration. Expressed in parts per million by weight.

Surface Filtration: Separates solids from liquid by trapping them on the surface of a filter medium.

  • Written by:
    Dave McGowan

    Dave McGowan

    Technical Manager, Kadant Solutions Division

© Kadant Inc.