Decanter Centrifuges 101 – Understanding the Basics of Separation

Decanter centrifuges are often used to separate solids from a liquid mixture. They are trendy in the chemical and pharmaceutical industries.

These centrifuges consist of a rotating cylindrical bowl and a conveyor screw or scroll placed coaxially. The conveying screw rotates at a different speed than the bowl, and it collects the solid particles and transports them to the decanter’s conical end.

 Advantages

Decanter centrifuges separate immiscible liquids using both gravity and centrifugal force. The heavier liquid or solid settles down as a sediment, while the lighter fluid rises to the top of the mixture. This separation occurs continuously, and the process is called decanting.

This heavy-duty industrial equipment is also highly durable and requires minimal maintenance, resulting in low operating costs. They have long, valuable lifespans and operate at high speeds, allowing them to handle large volumes of material quickly.

The most significant advantage of a Decanter Centrifuges is its ability to eject solids continuously. Disc stack and chamber bowl centrifuges cannot achieve this because the rotating surface contacts the inner fluid particles, restricting rotational velocity.

The Decanter Centrifuges also has a more extensive range of particle separation than chamber bowls and disc-stack centrifuges. The accumulated solids layer around the periphery of the bowl creates a pond inside which a scroll (auger) scrapes and pushes solids toward discharge ports located on the centrifuge bowl’s outer circumference.

 Disadvantages

Decanter Centrifuges can be expensive to operate compared to other solid-liquid separation equipment. They also require a high-horsepower motor to power them.

They are less effective for separating excellent particles and slower than other methods of settling suspensions. However, they provide the advantage of easy sludge dryness adjustment, which is impossible with other methods of clarifying liquids.

The Decanter Centrifuges is a specialized type of solid-liquid separator used in many industrial applications. Typical uses include:

• Classifying solids in a liquid suspension.
• Washing a solid from a slurry.
• Dewatering a slurry.

The chemical industry is one of the most significant users of the Decanter Centrifuges because it deals with various hazardous and toxic chemicals that need to be separated from the liquid stream for safer disposal. The demand for this type of separation equipment is expected to grow as more and more industries are looking for ways to minimize their environmental impact.

 Benefits 

There are numerous applications for liquid-solid separation that the decanter machine can handle. It can also process fluids with differing specific gravities and particle sizes. It is one reason why it is a popular choice for separating contaminated diesel fuel from its water phase.

The centrifugal force compacts the solids, ejecting them into the discharge ports at the bowl’s end. This action is controlled by a screw conveyor, commonly referred to as a drill, and is driven by a planetary gearbox.

The resulting clarified liquid overflows into dam plates at the bowl’s opposite end. Baffles within the Decanter Centrifuges casing guide the separated liquid phases into the correct flow paths to prevent cross-contamination. This simple but effective separation process is the key to reducing energy consumption and improving product quality.