LWS 3-Phase solid bowl decanter centrifuges

Principle of Operation

The centrifuge starts and automatically accelerates to the predetermined speed. The feed valve is opened, and the suspension to be separated enters the inlet distributor of the scroll conveyor through a stationary inlet tube and is accelerated smoothly into the bowl. Under centrifugal force, the suspension inside the bowl is quickly separated into three phases (solid phase, light Liquid phase, and heavy liquid phase). The denser solid phase is pressed outwards against the rotating bowl wall to form the sediment and is continuously moved to the conical beach section by the scroll conveyor, which rotates at a different speed than the bowl due to a gearbox. The sediment is compacted, with its surplus liquid being expelled by the centrifugal force in the conical beach section of the bowl, and then discharged out from the solids discharge ports. Meanwhile, the heavy liquid phase (such as water) is near the inner wall of the bowl, while the light liquid phase (such as oil) is far away from the inner wall, and different solid-liquid separation effects can be achieved by adjusting the weir plates at the large end of the bowl and different liquid-liquid separation effects can be got by regulating the interface position between the two liquid phases through an adjustable centripetal impeller during operation. The light liquid phase separated (such as oil) flows off over the weir plates, and the heavy liquid phase separated (such as water) is discharged under pressure via a centripetal pump situated at the end of the cylindrical part of the bowl. 

Design of products

LWS 3-Phase separating scroll conveyor decanters are mainly composed of rotor components (the scroll conveyor and the bowl, etc.), a planetary gear differential, dual motors (main and auxiliary motors), dual variable frequency drives, integrated frame components, fully sealed casing, feed tube assembly, an adjustable centripetal pump, cover, and an automatic control system, and can be used for a wide range of processes of 3-phase separation of liquid-liquid-solid or liquid-solid-liquid on various suspensions with significant differences in physical properties.

Special design features

The decanters have not only the features of a regular scroll conveyor decanter centrifuge, but also the features of the interface depth between the two liquid phases adjusted via an adjustable centripetal impeller during operation to accommodate for changing separation conditions, discharging heavy liquid phase under pressure, and discharging light liquid phase under gravity. The separation effect of the heavy and light liquid phases can be quickly and precisely adjusted by the adjustable impeller resulting in higher liquid purity, which eliminates the need for a traditional separate chamber pump for saving costs, with reading the adjusted scale and operating easily. The heavy liquid phase is discharged under pressure from the pond to the outlet for heavy liquids via a centripetal pump while the light liquid phase flows to the outlet for light liquids under gravity, which effectively avoids the cross-contamination of heavy and light liquids with the separate discharges of the two liquid phases. The adjustable impeller can be adjusted at any time to adapt to changing conditions of the feed, such as flow rate, solid phase concentration and liquids phase concentrations.

LWS 3-Phase solid bowl decanter centrifuge Standard Sizes and Technical Data