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Microscreens & Micro-Strainers

Microscreens (micro-strainers) — very fine rotating mesh, micron-scale, that removes algae, plankton and fine solids by surface straining ahead of sensitive intakes and SWRO membranes.

Microscreens & Micro-Strainers

Intake Screening for Water & Desalination Plants

A microstrainer is a fine-mesh rotating drum or disc, typically 15–60 micron, that removes algae, plankton and fine particulates by surface straining as water passes through. The captured mat is continuously washed off by jets. It is a polishing screen — reducing silt density index (SDI) and biofouling load — not a coarse protective screen.

Background & History

Micro-straining was developed in the 1940s and 1950s (notably by Glenfield & Kennedy) to remove algae from reservoir-derived potable supplies. It became a standard pre-treatment for algae-laden surface waters and, more recently, a useful SDI-reduction step ahead of reverse-osmosis desalination membranes.

Types & Variants

Configurations in service

Drum Micro-Strainer

Fine-mesh rotating drum with internal jet backwash.

Disc Micro-Strainer

Fine-mesh discs for a large area in a compact unit.

Stainless / Polyester Mesh

Mesh selected (15–60 micron) for algae and fine solids.

Jet Backwash

Continuous high-pressure jets clear the captured mat.

Advantages & Limitations

An honest engineering assessment

Advantages

  • Removes fine algae, plankton and fine solids
  • Very low head loss
  • Continuous operation with automatic backwash
  • Reduces downstream fouling and SDI ahead of SWRO/UF
  • Compact for the fineness achieved

Limitations

  • Fine mesh blinds and clogs — needs reliable backwash
  • Requires clean backwash water
  • Not coarse protection — needs upstream screening
  • Performance falls during heavy algal-bloom surges

Where It Fits

Typical applications

Microscreens suit reservoir and algae-laden surface supplies, potable pre-treatment, and SDI reduction ahead of SWRO and ultrafiltration in desalination.

Other Intake Screen Types

The full intake-screen series

Related Equipment & Hubs

Specify the right intake screen

Our engineers select and size intake screening — microscreens and the full train — matched to your debris load, fish-protection duty and downstream process.

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.

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