Decanter centrifuges, considered essential in numerous industries such as wastewater treatment, oil refining, food processing, and pharmaceuticals, serve as powerful industrial separation equipment. This informative article provides a comprehensive overview of decanter centrifuges, including their functionalities, applications, and operation. Let’s delve into it!
What is a Decanter Centrifuge?
Decanter centrifuges are crucial tools in various industrial settings where the separation of different densities is necessary. By continuously separating liquid from solid materials in a slurry, the decanter centrifuge (also known as a solid bowl centrifuge) plays an essential role in achieving efficient separation. It utilizes the principles of gravity to achieve effective liquid-solid separation through a high-speed rotation process. Due to its effectiveness, it is a vital piece of equipment in industries such as wastewater treatment, chemical processing, oil refining, and food production. However, its performance is influenced by multiple factors, and specific design guidelines must be adhered to based on the intended application. With uses ranging from biosolids wastewater treatment to two-phase dewatering in areas like chemical, food, oil, and mining industries, the decanter centrifuge has proven to be a valuable asset.
Applications
Decanter centrifuges are widely utilized to continuously extract large amounts of solids from liquids, with applications in various industries such as food processing, oil refining, fish processing, mineral processing, chemicals, and more. In addition, they are commonly used in wastewater treatment.
Main Components
Screw Conveyor
The screw conveyor, also known as a scroll conveyor, is a crucial component in any operation. It is comprised of a spiral blade that rotates at a slightly different speed than the centrifuge’s drum or bowl. This rotation effectively moves the settled solids towards the tapered end of the drum and out through the solids discharge port. To ensure longevity, tungsten carbide bricks are welded onto the edges of the scroll conveyor.
Inlet Section
The inlet section is an essential component of the centrifuge as it accelerates the feed slurry to match the rotation of the centrifuge bowl. Proper design of the inlet section is crucial for efficient separation of solids and liquids, while also protecting the feed solids from degradation and disturbance from sediment in the bowl. This ensures the decanter centrifuge can effectively separate particles and minimize blockages or interruptions during the process.
Solids discharge section
The solids discharge section of the system is designed to carefully discharge separated solids, including pastes and powders. The screw conveyor transports the settled solids to the conical end of the centrifuge bowl, where they are then discharged. This discharge area is strategically configured to prevent any erosion of components. Furthermore, any components that may be prone to erosion can easily be replaced within the solids discharge section, ensuring efficient and uninterrupted production.
Liquid discharge section
The liquid discharge section of the centrifuge is responsible for efficiently extracting the clarified liquid without losing significant solids or contaminants. It is designed to prevent cross contamination between the liquid phases and can have separate outlets for each phase in a three-phase system, or one outlet in a two-phase system, depending on the configuration and operating mode of the decanter centrifuge.
How does it work?
The centrifuge operates by having both the drum and spiral rotate in the same direction, with a speed difference. A solid-liquid mixture is consistently fed through the feed pipe into the inner cylinder of the spiral, then accelerated into the drum. Due to centrifugal force, denser solid particles separate and form a sediment layer on the drum wall. The feed spiral then continuously pushes the solid particles towards the cone end of the drum and expels them through the slag discharge port. The lighter liquid phase forms an inner liquid ring, constantly overflowing from the larger end of the drum and exiting the machine through the liquid outlet.