Three Phase Decanter Centrifuge for Oil-Water-Solid Separation

Three-Phase Decanter Centrifuge is designed for continuous separation of oil, water, and solids from oil-water-solid mixed materials.

A three-phase decanter centrifuge can separate:

• Light liquid phase: oil
• Heavy liquid phase: water
• Solid phase: sludge, sand, residue, or fine solids

This machine is suitable for oily sludge, oil-water-solid mixtures, industrial oily residues, and process streams where oil recovery, water phase separation, and solid residue discharge are required at the same time.

A three-phase decanter centrifuge separates materials according to density difference.

The solid phase is continuously discharged by the screw conveyor.
The oil phase and water phase are discharged separately through different liquid outlets. 

This structure allows the machine to complete oil recovery, water separation, and solids removal in one continuous process.

The oil-water-solid mixture enters the rotating bowl through the feed pipe.

Under high-speed centrifugal force, the heavier solid particles move outward and form a sediment layer on the inner wall of the bowl.

Because oil, water, and solids have different densities, they form different separation layers inside the bowl:

• Solids move to the outer wall
• Water forms the heavier liquid layer
• Oil stays closer to the center as the light liquid phase

The screw conveyor rotates at a controlled differential speed and continuously pushes the separated solids toward the discharge end.

At the same time, the oil phase and water phase are discharged separately through different liquid outlets.

For stable three-phase separation, the liquid interface, feed condition, oil-water ratio, solids load, viscosity, and pretreatment condition must be properly controlled.

Three-phase separation performance depends strongly on feed condition. In many projects, pretreatment is recommended before the centrifuge.

Common pretreatment options include:

Heating can reduce oil viscosity and improve oil-water separation.

It is useful when the material contains heavy oil, grease, tar-like components, or high-viscosity oil phase.

If oil and water are emulsified, demulsifier dosing may be needed.

Without proper demulsification, oil recovery may be low and water phase quality may be unstable.

Homogenization helps stabilize feed concentration, oil-water ratio, and solids distribution.

This is useful when the feed changes frequently.

Large stones, coarse solids, rags, or hard particles should be removed before entering the centrifuge.

This helps protect the rotating parts and reduce blockage risk.

The machine can separate oil, water, and solids continuously in one process, reducing the need for multiple separation units.

The screw conveyor continuously removes separated solids, making the machine suitable for feed materials with higher solids content.

When the feed contains recoverable oil, the three-phase decanter can help separate and recover the oil phase.

By separating liquid from solids, the machine helps reduce the volume of oily residue or sludge.

Compared with disc separators, three-phase decanters are more suitable for materials containing higher solids, sludge, sand, or residue.

Heating, demulsification, homogenization, and dosing systems can be integrated to improve separation performance.

With suitable pretreatment, stable feeding, proper interface control, and correct machine configuration, a three-phase decanter centrifuge can typically help achieve:

• 50–90% recoverable oil recovery, depending on oil content and emulsification level
• 70–95% solid capture rate, depending on particle size and feed condition
• 30–70% sludge or residue volume reduction
• Better separation of oil, water, and solid phases
• Lower solids load in separated liquid phases
• More stable oil recovery from mixed oily materials
• Reduced downstream disposal, heating, drying, or treatment load
• Continuous discharge of separated solids

Actual performance depends on oil content, water content, solids content, viscosity, temperature, particle size, emulsification level, pretreatment effect, and operating parameters.

For strongly emulsified materials or strict liquid quality requirements, pretreatment or downstream polishing may still be required.

To recommend a suitable three-phase decanter centrifuge, please provide:

• Feed material name
• Industry or process background
• Capacity requirement, in m³/h or tons/day
• Oil content
• Water content
• Solids content
• Particle size or solid characteristics
• Viscosity
• Temperature
• Whether the oil is free oil or emulsified oil
• Current pretreatment method, if any
• Target oil recovery rate
• Target water phase quality
• Target solid residue moisture or oil content
• Whether heating is allowed or required
• Whether demulsifier dosing is allowed
• Whether the feed contains large particles or sand
• Corrosion condition
• Abrasion condition
• Volatile or flammable components, if any
• Site hazardous area classification, if available
• Required operating hours per day
• Site voltage and control preference
• Need for skid-mounted system or not

If you have local customer channels or project resources involving oil-water-solid separation, oily sludge separation, recoverable oil treatment, industrial oily residues, or three-phase centrifuge projects, Peony welcomes cooperation.

Peony can support local agents, distributors, and project partners with technical model selection, three-phase separation process recommendation, pretreatment configuration, skid-mounted system integration, equipment manufacturing, installation guidance, commissioning support, spare parts, and after-sales service.

Please send us your target market, customer type, project background, and cooperation proposal. Our team will evaluate the opportunity and provide technical and commercial support for suitable three-phase separation projects.