Three Phase Decanter Centrifuge for Soapstock Oil Recovery
Description
The Three Phase Decanter Centrifuge for Soapstock Oil Recovery continuously separates recoverable oil, aqueous liquid, and concentrated solids from conditioned soapstock.
It is suitable for edible-oil refineries processing soybean, palm, sunflower, corn, rice bran, and other vegetable oils. Soapstock normally requires heating, acidulation, or chemical conditioning before three-phase separation.
Typical Applications
- Acidulated soapstock separation
- Acid oil recovery
- Vegetable-oil refinery sludge treatment
- Neutralization residue processing
- Soapstock wastewater pretreatment
- Oil recovery from wash-water sludge
- Refinery sludge-volume reduction
- Pretreatment before acid-oil purification
Soapstock Process Challenges
Stable Oil-Water Emulsions
Surfactants and fine particles can keep oil dispersed in water.
Heating, emulsion breakers, coagulation, or pH adjustment may be required before separation.
Variable Oil Content
Oil, water, and solids ratios may change with production and cleaning operations.
An equalization tank and adjustable phase interface help stabilize operation.
Fine Suspended Solids
Metal fines, rust, pigments, and polishing residues may remain suspended.
Suitable conditioning improves solids capture and liquid separation.
Sticky and Abrasive Sludge
Oil-coated metal particles may cause buildup and wear.
Flushing connections and carbide or ceramic protection can be provided.
Dissolved Pollutants
The centrifuge removes free oil and suspended solids but does not fully remove dissolved COD, salts, surfactants, or dissolved metals.
Further treatment may still be required.
Soapstock Oil Recovery Solution
Soapstock
→ Heated Agitated Tank
→ Acidulation / Conditioning
→ Three Phase Decanter Centrifuge
→ Recovered Oil + Aqueous Phase + Solids
Recovered Oil
→ Polishing / Drying / Acid-Oil Storage
Aqueous Phase
→ Neutralization / Wastewater Treatment
Concentrated Solids
→ Further Recovery / Disposal
Peony Can Provide
- Feed testing and centrifuge selection
- Heated and acid-resistant feed tank
- Controlled feed pump
- Acid and chemical dosing system
- Adjustable phase interface
- Corrosion-resistant wetted parts
- Flushing or CIP system
- PLC and dual-VFD control
How the Decanter Centrifuge Works
1. Conditioned Soapstock Feeding
Heated and conditioned soapstock enters the rotating bowl.
Agitation maintains stable temperature and composition.
2. Solids Sedimentation
Centrifugal force moves gums, meal fines, soap residues, and dense impurities toward the bowl wall.
A concentrated solids layer forms.
3. Oil-Water Separation
The lighter recovered-oil phase remains closer to the bowl center.
The heavier aqueous phase forms a separate outer liquid layer.
4. Continuous Solids Conveying
The screw conveyor transports settled solids toward the conical discharge end.
Concentrated solids discharge continuously.
5. Three-Phase Discharge
Recovered oil and aqueous liquid leave through separate outlets.
The solids discharge continuously for further treatment or disposal.
Technical Parameter
| Model |
Diameter (mm) |
Length (mm) |
Length-to-diameter rate |
G force |
Max solid discharge (m³/h) |
Weight (kg) |
Dimension (L*W*H) (mm) |
| PDC-10 |
250 |
1000 |
4 |
4080 |
0.4 |
1000 |
2410*800*1080 |
| PDC-12 |
4200 |
1350 |
4 |
3500 |
0.6 |
1200 |
2610*800*1080 |
| PDC-12 |
4200 |
1350 |
4.5 |
3180 |
1.2 |
1800 |
3495*840*1180 |
| PDC-18 |
4000 |
1600 |
4.5 |
3180 |
1.2 |
3200 |
3497*1020*1385 |
| PDC-18 |
450 |
2150 |
4 |
2500 |
2 |
3800 |
4447*1080*1385 |
| PDC-20 |
400 |
2250 |
4.5 |
2500 |
3.5 |
4000 |
4580*1140*1470 |
| PDC-21 |
530 |
2280 |
4.3 |
2500 |
5 |
5000 |
4924*1170*1540 |
| PDC-26 |
655 |
2800 |
4.3 |
2270 |
8 |
7000 |
4300*1900*1350 |
Main Advantages
Improved Acid-Oil Recovery
Recovers valuable oil from conditioned soapstock and refinery residues.
Continuous Three-Phase Separation
Separates oil, aqueous liquid, and solids in one continuous process.
Reduced Wastewater Load
Removes recoverable oil and suspended solids before wastewater treatment.
Corrosion-Resistant Configuration
Wetted materials can be selected for acidic operating conditions.
Stable Automatic Operation
Adjustable speed, feed rate, and phase interface support changing feed conditions.
What Data Is Needed for Selection?
Please provide:
- Oil, water, soap, and solids content
- Feed temperature, pH, and viscosity
- Required capacity
- Acidulation method
- Oil-recovery target
- Downstream process
FAQ
Can untreated soapstock be separated directly?
Usually not efficiently. Acidulation, heating, or chemical conditioning is often required to break the soap emulsion.
Can the centrifuge recover acid oil?
Yes. It separates acid oil from the aqueous phase and precipitated solids after suitable acidulation.
Which material is suitable for acidic soapstock?
SS316L or duplex steel is commonly considered. Final selection depends on pH, temperature, chlorides, and acid type.
Can the recovered oil be used directly?
Usually further drying, filtration, or purification is required. Final use depends on oil quality and local regulations.
How is buildup from gums and soap solids controlled?
Stable heating, automatic flushing, CIP cleaning, and suitable differential-speed control help reduce deposits.
Contact Peony for Partnership
Peony supports edible-oil refineries, acid-oil processors, soapstock recyclers, wastewater contractors, and engineering companies.
Send us your soapstock composition, pH, temperature, capacity, and recovery target. Our engineering team will recommend a suitable three-phase decanter centrifuge solution.
