In the context of zero liquid discharge (ZLD) systems, a centrifuge is a type of mechanical equipment use for the separation and dewatering of solids from liquid streams. It is an essential component in ZLD processes to achieve the goal of eliminating liquid discharge by recovering and recycling water from wastewater.

System Components

Drum or Bowl: The centrifuge consists of a rotating drum or bowl, typically made of stainless steel or other durable materials.
Feed Inlet: The liquid-solid mixture enters the centrifuge through a feed inlet, usually located at the top or side of the drum. 
Rotation and Centrifugal Force:  This rotation generates centrifugal force, causing the solids to migrate toward the drum’s walls while the liquid phase remains in the center.
Separation and Dewatering: As the mixture spins within the drum, the denser solids settle against the drum’s walls due to the centrifugal force. 
Solids Discharge: The concentrate solids accumulate on the drum’s walls and are gradually push toward the solids discharge end of the centrifuge.

Process Description

A centrifuge operates base on the principle of centrifugal force, which is generated by spinning the liquid-solid mixture at high speeds. This force causes the denser solids to settle and separate from the liquid phase, allowing for the removal of water and concentration of solids.

Significance & Advantages

Centrifuges use in ZLD systems are design to handle high volumes of liquid and concentrate the solids efficiently. They offer advantages such as high separation efficiency, compact size, and versatility in handling a wide range of solid-liquid mixtures. The choice of centrifuge type, size, and operating parameters depends on factors such as the nature of the wastewater, desire solids concentration, and process requirements.