Industrial Three-Phase Decanter Centrifuge for Sludge

Three-Phase Decanter Centrifuge Product Introduction

The Industrial Three-Phase Decanter Centrifuge for Sludge is designed for continuous separation of solids and two immiscible liquid phases in industrial sludge, oily wastewater, chemical residues, and municipal treatment applications. Unlike a standard two-phase decanter, this machine separates the feed into solid cake, heavy liquid, and light liquid within one enclosed process.

The system uses a high-speed horizontal bowl and an internal screw conveyor to generate strong centrifugal force and continuously discharge separated solids. Adjustable bowl speed, differential speed, liquid-layer depth, and feed rate allow the machine to adapt to different sludge concentrations and phase-separation requirements. With a robust frame, PLC control options, and multiple processing capacities, it provides an efficient solution for reducing sludge volume, recovering valuable liquids, and improving wastewater treatment performance.

Industry Pain Points

• Oil, water, and solids are difficult to separate efficiently by gravity settling alone.

• High sludge moisture increases transportation and disposal costs.

• Batch treatment methods require frequent shutdowns and manual cleaning.

• Fluctuating feed concentration can reduce separation stability.

• Fine suspended solids may remain in recovered liquid phases.

• Poor oil recovery can cause product loss and increase wastewater load.

• Open treatment systems may create odor, leakage, and workplace contamination.

• Traditional filters may block easily when processing oily or sticky sludge.

Our Solution

The three-phase decanter centrifuge combines continuous solids dewatering with simultaneous separation of light and heavy liquids.

The feed enters the rotating bowl and is rapidly accelerated. Under centrifugal force, the dense solids move toward the bowl wall, the heavier liquid forms a middle layer, and the lighter liquid remains closer to the bowl center. The internal screw conveyor transports the settled solids toward the discharge end, while the two liquid phases leave through independent outlets.

This design allows one machine to complete:

• Solid-liquid-liquid separation
• Continuous sludge dewatering
• Oil recovery
• Water clarification
• Automatic solids discharge
• Reduced downstream treatment load

Working Principle

1. Feed Introduction

The sludge mixture enters through the central feed pipe and is distributed smoothly into the rotating bowl.

2. High-Speed Centrifugal Separation

The bowl generates strong centrifugal force, causing the phases to separate according to density.

3. Solid Sedimentation

The densest solid particles settle against the inner wall of the bowl.

4. Heavy-Liquid Layer Formation

The heavier liquid phase, usually water, forms a layer inside the solids zone.

5. Light-Liquid Layer Formation

The lighter liquid phase, usually oil, remains closer to the rotational axis.

6. Solids Conveying

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

7. Three-Phase Discharge

The separated solids, heavy liquid, and light liquid leave through independent discharge paths.

Process Description

Sludge Storage → Mixing or Heating → Feed Pumping → Three-Phase Centrifugal Separation → Oil Recovery → Water Discharge → Solid Cake Collection

Before separation, the sludge may be heated or chemically conditioned to improve phase release. The feed pump then supplies the material to the decanter at a controlled rate. Inside the bowl, oil, water, and solids separate continuously. The recovered oil can be collected for reuse or further purification, clarified water can enter downstream treatment, and solids can be conveyed for disposal or additional processing.

Main Features

• Continuous three-phase separation

• Simultaneous oil, water, and solids recovery

• High-speed horizontal bowl design

• Internal screw conveyor for automatic solids discharge

• Adjustable bowl and differential speeds

• Stable performance under changing sludge conditions

• PLC automatic control available

• Multiple capacities for different treatment requirements

• Enclosed system for cleaner operation

• Heavy-duty industrial structure

• Reduced manual handling

• Suitable for continuous wastewater and sludge treatment

• Wear-resistant components available

• Customizable material and control configuration

Suitable Materials

• Oily sludge
• Tank-bottom sludge
• Refinery sludge
• Municipal wastewater sludge
• Industrial wastewater
• Oil-water emulsions
• Chemical residues
• Food-processing sludge
• Edible-oil processing waste
• Metalworking fluids
• Biological sludge
• Compatible liquid-solid mixtures

The actual separation result depends on density difference, viscosity, emulsion stability, temperature, particle size, and solids concentration.

Technical Specifications

Parameter	Specification
Equipment Type	Industrial Three-Phase Decanter Centrifuge
Separation Function	Solid + Heavy Liquid + Light Liquid
Main Application	Sludge and Oily Wastewater Treatment
Processing Capacity	Approx. 0.5–20 m³/h, depending on configuration
Operation Mode	Continuous Automatic Operation
Bowl Structure	Horizontal Cylindrical-Conical Bowl
Solids Discharge	Continuous Screw Conveyor
Control System	PLC Automatic Control Optional
Speed Control	Variable-Frequency Control
Process Material	Stainless Steel Contact Parts Optional
Frame Material	Carbon Steel or Stainless Steel
Installation Type	Fixed Industrial Installation
Cleaning Method	Flushing or CIP-Compatible Configuration
Application Industries	Wastewater, Chemical, Oil, Food, Environmental
Customization	Capacity, Material, Voltage, Control, Wear Protection

Available Capacity Range

Configuration	Typical Capacity
Small Unit	0.5–3 m³/h
Medium Unit	1–5 m³/h
Medium-High Unit	3–6 m³/h
Large Unit	8–10 m³/h
High-Capacity Unit	10–20 m³/h

Actual capacity must be confirmed through material data or separation testing.

Application Scenarios

Oily Wastewater Treatment

Separates free oil, water, and suspended solids from industrial wastewater streams.

Tank Bottom Sludge Processing

Recovers oil and removes water and solids from sludge accumulated in storage tanks.

Refinery Sludge Treatment

Used for refinery residues, API sludge, and compatible oily waste streams.

Municipal Wastewater Sludge

Applied where sludge contains floating oil or requires simultaneous liquid-phase separation.

Chemical Processing Plants

Separates solid residues and immiscible liquid phases from chemical production waste.

Food Processing Wastewater

Suitable for oily wastewater containing fats, water, and suspended organic solids.

Edible Oil Processing Residues

Used for compatible oil-water-solid mixtures generated during refining and cleaning operations.

Metalworking Wastewater

Processes oily coolant waste, metal fines, and water-based industrial residues.

Environmental Remediation

Treats contaminated sludge and oily soil-washing liquids.

Industrial Recycling Systems

Recovers reusable light-liquid phases while reducing waste volume.

Installation Recommendations

• Install the unit on a rigid, level foundation.

• Keep the feed flow stable and avoid sudden concentration changes.

• Use an agitated tank to prevent solids settling before feeding.

• Install separate pipelines for oil, water, and solids discharge.

• Avoid excessive back pressure at the liquid outlets.

• Provide sufficient maintenance clearance around the bowl and drive units.

• Install heating or pretreatment equipment when required by the sludge.

• Confirm motor rotation and control logic before feeding material.

• Flush the bowl before shutdown to prevent hardened deposits.

Maintenance Recommendations

• Inspect bearings, seals, and lubrication points regularly.

• Monitor vibration, motor current, torque, and bearing temperature.

• Check screw flights and discharge ports for wear.

• Clean the bowl after processing sticky or hardening materials.

• Inspect oil and water outlet passages for blockage.

• Replace wear-resistant parts before the base metal becomes exposed.

• Verify sensor and safety interlock operation periodically.

• Rebalance rotating components after major repair.

Why Choose This Equipment

✓ Simultaneous oil-water-solid separation

✓ Continuous automatic operation

✓ Reduced sludge volume and disposal cost

✓ Improved oil recovery

✓ Adjustable separation parameters

✓ Multiple capacity options

✓ Suitable for difficult industrial sludge

✓ PLC and VFD control available

✓ Enclosed and cleaner process

✓ Custom configurations for different materials

FAQ

1. What is a three-phase decanter centrifuge?
A three-phase decanter centrifuge is a continuous separation machine that separates solid particles, heavy liquid phase, and light liquid phase from mixed materials in one process. It is widely used for sludge treatment, oily wastewater, and industrial waste separation.

2. What is the difference between a two-phase and three-phase decanter centrifuge?
A two-phase decanter centrifuge separates solid and liquid, while a three-phase decanter centrifuge separates solid, heavy liquid (such as water), and light liquid (such as oil) simultaneously. It is especially suitable for oil-water-solid separation applications.

3. What materials can be processed by this centrifuge?
The centrifuge can process oily sludge, municipal wastewater sludge, refinery sludge, chemical waste, food processing wastewater, oil-water mixtures, and various industrial wastewater containing suspended solids.

4. How does the three-phase separation process work?
The mixed material enters the rotating bowl, where strong centrifugal force separates different phases according to density. Solid particles move to the bowl wall, heavier liquid forms the middle layer, and lighter liquid remains closer to the center before separate discharge.

5. Is this centrifuge suitable for oily wastewater treatment?
Yes. The three-phase decanter centrifuge is designed for oily wastewater and sludge applications. It can recover oil, remove water, and discharge solids continuously, helping reduce waste treatment costs.

6. Does the machine require continuous manual operation?
No. The equipment is designed for continuous automatic operation. Feeding, separation, solids discharge, and liquid discharge can be controlled automatically with optional PLC control systems.

7. What factors affect separation efficiency?
Separation performance depends on material characteristics such as solid content, particle size, density difference, viscosity, temperature, emulsion stability, and operating parameters including bowl speed and differential speed.

8. Can the centrifuge be customized for different applications?
Yes. The centrifuge can be customized according to processing capacity, material properties, contact material, voltage requirements, wear protection, control system, and specific industry needs.

 

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