Decanters
Alfa Laval decanter centrifuges help you with solid-liquid separation within one single continuous process. Stand out from the competition with high performance separation that results in extracted / clarified products of excellent quality and higher commercial value. Make a difference as you recover valuable raw materials, reduce energy consumption and lower footprint and waste management costs with our industrial decanter centrifuge machines and services.
Make a difference to your business and the environment:
- High-performance separation, resulting in high-value products and low waste management costs
- Low energy consumption and carbon footprints
- Low maintenance costs thanks to continuous operation, high-grade machine materials, smart design and well-thought preventive services
- Low capital cost/capacity ratio
Solid-liquid separation is a common manufacturing process and Alfa Laval has more than 60 years of experience in decanter centrifuge uses to meet this requirement in various industries. Together with our industry know-how and specialist process experience from all over the world, Alfa Laval can match your exact needs for each particular application and installation.
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How does a decanter centrifuge work?
Solid-liquid separation - Innovation using centrifugal force
Separating solids from liquids plays a key role in countless industrial processes. Traditionally, many businesses use a clarifier or settling tank, in which particles, sediment and solids gradually fall to the bottom due to the force of gravity. However, such clarification is an extremely slow process with not so controllable results.
To accelerating the process, decanter centrifuge operation makes use of centrifugal force – the effect can be up to 4000 times greater compared to using gravitational forces. Solid-liquid separation can also be easily controlled by adjusting the speed of rotation.
During solid-liquid separation, centrifugal forces act on the process stream, causing the denser solid particles to migrate outward toward the rotating bowl wall, while the less dense liquid phase forms a concentric inner layer in an Alfa Laval decanter centrifuge. Regardless of whether it is a decanter for water, food, or energy applications, interchangeable power recovering tubes or plates are employed to adjust the liquid depth—commonly referred to as the “pond level”—to meet specific process requirements.
The solids are continuously removed by a screw conveyor rotating at a different speed than the bowl. This controlled speed differential enables the gradual transport of separated solids out of the pond and along the conical section, or “beach,” for efficient discharge.
Centrifugal forces within Alfa Laval decanters compact the solid phase and expel surplus liquid, resulting in a dewatered "cake" that is subsequently conveyed and discharge from the bowl. The clarified liquid phase—or multiple phases in the case of three-phase separation—overflows the dam plates or PowerTubes situated at the opposite end of the bowl. Internal baffles within the decanter casing direct each phase into its designated flow path, ensuring proper collection and eliminating cross-contamination risk.
To accommodate fluctuations in the incoming solids loading, the speed of the screw conveyor may be automatically adjusted via a variable frequency drive (VFD) in combination with a torque control system, which continuously monitors the torque load on the conveyor. When solids loading increases, the system automatically adjusts the differential speed to prevent torque overload, ensuring stable operation and consistent dryness of the discharged solids. Conversely, under lighter loads, this speed is reduced to minimize wear and energy consumption.
Enabling precise control is a significant advantage for those seeking optimal solid-liquid separation efficiency, reliable decanter performance under varying process conditions, and extended equipment life.
Benefits
What are the benefits of decanter centrifuges compared to other types of separation equipment?
Faster separation in single continuous process
Our horizontal centrifuges separate solids from one or two liquid phases in one single continuous process in a continuous, high-speed process. This enhances productivity and thus, profitability.
Wide-ranging feed variations and controllable performance
Alfa Laval centrifugal decanters are designed to handle a wide range of solid particles with diameters from 5 mm to a few microns.
Our industrial decanter units can also handle slurries with a solid content from as low as 0.1% w/w to more than 65% w/w.
Controllable centrifugal forces and other specific configuration details mean process optimization according to your specific requirements and goals, such as end-product of high market fit at the lowest possible costs.
Decanter Centrifuge Manufacturers And Partners - Why Alfa Laval?
Global industry leader
Founded in 1883, Alfa Laval has led the way in centrifugal separation technology with continuous breakthroughs, and our high-performance decanter centrifuge is one of them. We have had practical experience with the design and manufacture of decanter centrifuges since the 50s. Today, with facilities all over the world, Alfa Laval is in a position to provide customers with superior products, superior service and superior results at any location.
Advanced material and technology
Alfa Laval uses high-grade stainless steel for all parts that come into contact with the solid-liquid separation process, in order to avoid any risk of the corrosion associated with the use of carbon steel.
Rotating components of Alfa Laval decanter centrifuges exposed to high stress are machined from high-strength centrifugally cast stainless steel. This ensures castings with a uniform grain structure free from flaws and defects as well as a completely weld-free finished component. The results are maximum strength, unparalleled reliability and a long service life.
All wear-prone areas of Alfa Laval centrifuges – the feed zone, solids discharge output zone, bowl and scroll – are protected by abrasion resistant material, selected to match the pattern of wear in each particular industrial process.
Continual refinement of the seal technology used in Alfa Laval decanter centrifuges is ensured by our technological resources. This is an area where Alfa Laval expertise and experience also make a key difference.
Service
As a decanter centrifuge manufacturer and solution provider, Alfa Laval has full control over the entire supply chain, which means that we can provide customers with response times, availability and lead times that are second to none.
Our worldwide service capabilities and vast experience with the contract maintenance and service of decanter centrifuges ensure that any service work required involves the absolute minimum of disturbance to operations.
For customized service solutions, our performance agreement can be tailored to your specific needs, with the aim to maximize your performance and reduce your operating costs.