The ALDRUM G3 sets new standards for sludge thickening with an enhanced design that achieves greatly improved process performance at minimum operating cost.

ALDRUM G3 Drum thickener

A revolution in sludge thickening

The Alfa Laval ALDRUM G3 Sludge Thickeners is ideal for mechanical thickening of sludge to optimize subsequent processes such as digestion with higher biogas production or more cost-efficient dewatering. They handle capacities from 15-180 m3/h.

Some particularly difficult sludge types, which previously required liquid polymer to flocculate and thicken, can now be treated using a combination of the ALDRUM G3 and cheaper powder polymer, thus reducing operating costs. A new conveyor design ensures the most effective distribution and flow of the sludge in the drum, resulting in improved separation efficiency even without the standard tilting mechanism.

Intermittent cleaning using the integrated Cleaning In Place system ensures low water consumption using either potable water, final effluent or treated filtrate.

Performance made simple

  • Greater capacity from the same footprint
  • Excellent process performance
  • Low polymer consumption, ensuring low operating costs
  • Simple, easy operation and maintenance
  • Outdoor installation, if required
  • Enclosed design for a clean, odourless working environment
  • Easier cleaning and maintenance, as a result of self-cleaning design
  • Greater safety due to cover switch and slam-proof cover
  • Selection of control panels and auxiliary equipment available to meet virtually any specific processing requirement

How it works


The ALDRUM drum thickener works on the principle of conveying polyelectrolyte treated sludge (a.k.a. flocculated sludge) through a slowly rotating drum filter. The sludge remains in the drum, while the water phase passes through the filter cloth.

Water consumption is low due to intermittent cleaning of the drum using either potable water, final effluent or treated filtrate. The ALDRUM can be adjusted to suit individual sludge thickening needs. It is possible to achieve the most efficient thickening by varying the feed rate, the polymer type and dosage, the drum speed and the spraying interval. The most cost-effective flocculation and polymer dosage is achieved by installing a flocculation reactor and/or mixing valve upstream of the actual drum thickener.

Meeting your exact requirements

A selection of auxiliary equipment is available for the complete ALDRUM range:

Mixing valve: Ensures thorough mixing of polymer and sludge. Can be installed directly onto the inlet of the drum thickener, or before the flocculation reactor

Flocculation reactor: Simple open reactor that kick-starts the creation of largeand strong flocks. Can be installed directly onto the inlet ofthe drum thickener

Sludge hopper: Leads the thickened sludge to the sludge pump in a controlled and efficient manner

Basic control panel: Straightforward, user-friendly control of the drum thickener,including control of the level in the flocculation reactor (if fitted)

Advanced control panel: All-in-one control solution. Control of the plant’s feed pump, sludge pump and polymer pump, as well as the drum thickener, the level in the flocculation reactor and the sludge hopper.