Decanter centrifuge

Maximum performance, minimal environmental impact

Throughout the entire world, Alfa Laval is recognised as a very competent supplier of decanters for sludge dewatering at purification plants. Alfa Laval’s competency within this area is unrivalled and that is why Stjernholm has decided to cooperate with Alfa Laval with regards to marketing decanters within the Danish market.

The Aldec series consists of 3 different machine series: Aldec, Aldec G2 and Aldec G3. They are all based on the same, thoroughly tested technology. Only the local conditions determine the optimal type of decanter to use: capacity needs, control requirements, space, requirements related to dewatering degree, requirements with regards to expansion options etc.

Separation takes place in a horizontal, cylindrical ball which is equipped with a conveyor. The medium is led into the ball through a stationary inlet pipe and it is smoothly accelerated by means of an inlet rotor. The centrifugal force leads to dry matter depositing on the ball wall. The conveyor rotates in the same direction as the ball, but at a different speed, making the dry matter move towards the conical end of the ball by the sludge outlet.

No matter which model you select, you will get a very compact decanter with a high degree of cost-effectiveness and operational reliability, and easy handling. The Aldec series has fully enclosed process sections, thereby offering a high level of hygiene.

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When you cooperate with us, you know that we are focusing on delivering a solution to you that adds value to your facility.


  • Typical energy savings of 20%.
  • Deposit savings of 5% compared to competing products.
  • Typical payback time of 5-7 years.
  • Minimal need for spare parts.


  • Eco-friendly engines and the newest improvements from Alfa Laval offer savings of up to 20% compared to similar products, and these savings are direct CO2 savings.
  • High dry matter levels of up to 35% lead to lower deposit levels and thereby less transport and lower CO2 emissions from the facility.
  • A decanter has the lowest polymer consumption level compared to other technologies.


  • Service-friendliness and operational reliability contribute to minimising the need for staff to touch the waste water, creating better working conditions and reducing absenteeism due to illness.
  • System installation, pipe installation and placement of necessary equipment is carried out in consideration of easy and safe inspection and service tasks.
  • We focus on the working environment and no matter where our products are manufactured, the goal is always a working environment according to Danish standards.

Thomas Fleischer Christiansen

92 15 22 15

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Stjernholm A/S

Stjernholm A/S
Langelandsvej 4A
8940 Randers SV
CVR: 28 88 49 66
+45 70 20 25 05


Stjernholm US Inc

Post Oak Blvd.
Suite 1910
Houston, TX 77056 US
+1 346 388 2791