Dolphin Centrifuge supplies three-phase industrial waste oil centrifuge systems — disc stack separators that continuously remove oil, water, and solids from contaminated waste oil at up to 12,000 Gs. These systems separate particles to 1 micron and all free water, processing 3 to 100+ GPM without filter media.
Operation
Alfa Laval Waste Oil Centrifuge (10 GPM)
A waste oil centrifuge works by exerting gravitational forces up to 12,000 Gs to separate sediment and water from waste oil. This force separates particles as small as 1 micron from the waste oil. The centrifuge has a flow-through design that enables the continuous flow of the separated contaminants through separate outlets.
Industrial waste oil centrifuges offer a large processing capacity. Continuous three-phase separation is the key to the efficient separation of waste oils.
Three-phase separation means the separation of the three phases in contaminated oil:
- Light phase — oil (the clean, recovered product)
- Heavy phase — water (separated and discharged continuously)
- Sludge — solid contaminants (intermittently ejected from the bowl)
A waste oil centrifuge is a heavy-duty, industrial-grade machine. It has the added capacity to self-eject the separated solids. It also discharges the separated water continuously through a discrete heavy-phase outlet.
Performance Results
Centrifuge performance refers to the cleaning ability of the centrifuge on waste oil. In this section, we answer the question:
Waste Oil Before and After Disc Stack Centrifuge
How well does a disc centrifuge clean waste oil?
The following is a real-world example of our centrifuge performance results on waste oil. The table shows the contaminant levels in waste oil before and after an Alfa Laval MOPX 207 Centrifuge.
| Alfa Laval MOPX-207 — 3-Phase, Self-Cleaning | ||
|---|---|---|
| Contaminant | Before | After |
| Sediment | 0.42% Wt. | 0.06% Wt. |
| Water | 38.0% Vol. | 1.2% Vol. |
| Metals: | ||
| Vanadium | 28 ppm | 31 ppm |
| Aluminum | 495 ppm | 85 ppm |
| Silicon | 386 ppm | 132 ppm |
| Ash Content | 1.17% Wt. | 0.09% Wt. |
Factors Affecting Centrifuge Performance
Temperature
Processing temperature is a key consideration while sizing waste oil centrifuges. Higher process temperature reduces the oil viscosity, which enables higher throughput.
Conversely, lower-temperature oil leads to lower capacity through the same centrifuge.
Flow Rate
Lower flow rates give higher retention time in the centrifuge bowl. This time enables longer exposure to the high centrifugal forces leading to better separation.
Inversely, higher flow rates lead to less effective separation.
Sizing
Industrial Centrifuge Systems for Waste Oil
Industrial centrifuges used for waste oil purification are sized based on their throughput or processing capacity. Centrifuges with processing capacities from 3 Gallons per Minute to over 100 Gallons per Minute are available for sale.
Due to the higher sludge levels in waste oil than in lube or hydraulic oil, self-cleaning centrifuges are required for waste oil processing.
For example, consider our medium capacity, self-cleaning Alfa Laval centrifuge, widely used for waste oil recovery. Notice the reduction in capacity at reduced oil temperature in the specifications below.
Advantages of Centrifuges Over Filters
- Total mechanical separation eliminates the need for filter media
- Automatic operation eliminates labor costs
- Continuous separation without the downtime/labor associated with filter replacement
- High g-force allows the centrifuge to separate particles down to 0.5 micron level
- A waste oil centrifuge will also separate all free water
- Breaking of waste oil emulsion
- Removing ash and fine metal particles from used engine oil
Filter vs Centrifuge Comparison
Waste Oil Centrifuge FAQ
What is a waste oil centrifuge?
How does a waste oil centrifuge work?
What size waste oil centrifuge do I need?
Can a centrifuge remove water from waste oil?
What is the difference between a waste oil centrifuge and a filter?
Need Help Sizing a Waste Oil Centrifuge?
Tell us your daily volume, oil type, and processing temperature. Our engineers will recommend the right centrifuge system for your waste oil application.
Specifications
The following table highlights the specifications of our most popular large-scale waste oil processing disc-stack centrifuges.
| Specification | MOPX207 Self-Cleaning | MOPX 210 Self-Cleaning |
|---|---|---|
| Separation @ 200°F | 1µ; All Free Water | 1µ; All Free Water |
| Rated Capacity | 32 GPM | 72 GPM |
| @ 70°F (Ambient) | 5–7 GPM | 12–15 GPM |
| @ 140°F | 10–12 GPM | 20–24 GPM |
| @ 200°F | 20+ GPM | 45+ GPM |
| Drive Motor | 7.5 HP | 15 HP |
| Voltage | 230/460V 3-Phase | 230/460V 3-Phase |
| Bowl Speed | 7,200 RPM | 5,100 RPM |
| G-Force | 7,200 Gs | 6,800 Gs |
| MOC | 316L SS Bowl; Nickel non-SS | 316L SS Bowl; Nickel non-SS |
| Skid Size | 4'×5'×6'H | 6'×7'×8'H |
| Weight | 2,800 Lbs | 4,000 Lbs |
Alfa Laval MOPX-210 Centrifuge System
Black Diesel
Alfa Laval Black Diesel Centrifuge
Black diesel is a term used to describe used engines and other used mineral oils that are repurposed as fuel for diesel engines and diesel generators. Read more about our black diesel centrifuges.
Installation
Waste Oil Centrifuge Setup — Panama
A typical waste oil centrifuge installation requires certain auxiliary equipment and site features for the optimum and durable operation of the centrifuge system.
Recommended ancillary equipment:
Elevated Platform
Self-cleaning centrifuges discharge sludge through the bottom. An elevated platform allows a sludge receptacle below.
Overhead Lifting Device
Disc stack centrifuge bowls are heavy parts needing mechanical assistance for retraction and reinstallation during service.
Extended Access Platform (Catwalk)
Provides operator access for operation and service. A guardrail is essential for safety at the elevated location.
Sludge Receptacle & Transfer Pump
A sludge tank with an attached pump is the ideal way to handle separated sludge discharged from the centrifuge.
Operating Water Supply
A non-corrosive water supply pipe with minimum recommended flow rate for trouble-free operation.
Industrial Scale Waste Oil Processing
Small-scale centrifuges (open, top-loading type) produce approximately 2,500 g force. This force is enough to separate bulk sludge from the waste oil but not separate the small particles.
Alfa Laval Disc Centrifuge — Waste Oil Recovery
Our industrial waste oil centrifuges generate up to 8,000 g's. Separating microscopic solid particles from the contaminated oil requires a higher g-force. Industrial centrifuges best handle the commercial processing of waste oil. Alfa Laval disc stack centrifuges have a continuous flow-through design and are perfect for this application.
Industrial-scale waste oil centrifuges are NOT cost-competitive for DIY or small-scale WVO separation. These waste oil centrifuges are workable for large-scale or commercial processors.
Our turn-key waste oil purification systems range from 500 Gal/Day to over 10,000 Gal/Day.
Decanters For High Sludge Waste Oil
Alfa Laval Decanter for Waste Oil De-Sludging
Waste oil decanters are well suited for de-sludging of high-sludge waste oil. Refinery waste slop and tank bottom sludge are typical examples. This process is also known as sludge thickening. A decanter centrifuge continuously handles high levels of sludge (up to 40%).
Alfa Laval decanters replace belt presses and screw presses in many demanding high-sludge applications.
Waste Oil Filter versus Centrifuge
This section will delve into commercial aspects of waste oil recycling using filters versus centrifuges.
Using Filters for Waste Oil Recycling
Filtration is not suitable for large-scale processing of used engine oil due to the ongoing cost of labor and material involved.
Consider a large-scale used oil collector who wants to process 10,000 gallons daily. Their collection consists of WVO, UCO, Waste Oil, Yellow Grease, and any other used oil. The first step involves heating and settling to remove the free water.
This process requires significant tank volume with heat for the 'heating and settling' routine. Despite the time and heating cost, this method still does not remove all free water.
Stainless Steel Waste Oil Centrifuge
If you have simple, routine questions: We have condensed our 40+ years of disc-stack centrifuge experience into 101 Frequently Asked Questions about Disc Stack Centrifuges!
Let's not forget about the sludge left in the settling tanks! That sludge contains significant amounts of oil, which means lost revenue. Also, the tank bottoms need cleaning.
Next, filtering the decanted waste oil through bag filters is labor-intensive. Replacing and disposing of filter media adds to cost and time. Cleaner oil requires small mesh filters, which means frequent media replacement and more material and labor costs.
The 'finished product' contains water. Water removal requires adsorption or 'boiling off,' which adds extra cost to the process. Water removal by settling adds time to the process.
The capital expense of centrifuge equipment is more compared to decanting and filtration. The payback period of a centrifuge system is short, considering all costs. It is often in months, depending on the volume of oil processed.
Waste Oil Separation Using Industrial Centrifuge
Waste Oil Processing — Industrial Scale
Process Flow Diagram for Industrial Scale Processing
A decanter centrifuge is a heavy-duty continuous de-sludging machine. It generates approximately 3,100 times the force of gravity by centrifugal force. The decanter centrifuge processes incoming crude oil to remove all solids from 1/2" down to a 50-micron level in a single pass.
The de-sludged oil and water are then pre-heated. A high-efficiency inline electric heater heats the fluid. An inline electric heater is energy efficient because it heats only the in-process liquid. Heating the entire tank volume is wasteful.
The heated waste oil is now processed through a self-cleaning, high-speed disc centrifuge. These industrial centrifuges generate up to 12,000 times the force of gravity. This g-force is enough to separate all free water and solid particles down to the 0.5-micron level.
This centrifuge machine continuously separates the water and intermittently ejects the separated solids. A PLC in the local centrifuge control panel controls the entire process. It also controls the sludge ejection system.
The process illustrated and described above is ideal for commercial-scale waste oil purification. This separation is a continuous process without media and labor costs.
Have you considered a centrifuge for Pyrolysis Oil separation? Please read our article using Industrial Centrifuges for Pyrolysis Oil production.
Used / Remanufactured Alfa Laval Centrifuges for Waste Oil Recovery
The following models show 3 Alfa Laval centrifuges of different capacities for processing Used Engine Oil. Hover on each model for technical specifications.
Alfa Laval WHPX 405
| Type: | 3-Phase; Self-Cleaning |
| Bowl RPM: | 8,500 RPM |
| G-Force: | 8,000 Gs |
| Capacity: | 5 GPM @ 180°F |
| Motor: | 4 HP |
| Power: | 460V; 20A |
| Size: | 4'×5'×5'H |
| Weight: | 1,800 Lbs |
Alfa Laval MOPX 213
| Type: | 3-Phase; Self-Cleaning |
| G-Force: | 8,000 Gs |
| Capacity: | 40 GPM @ 180°F |
| Motor: | 10 HP |
| Power: | 460V; 50A |
| Size: | 5'×6'×7'H |
| Weight: | 3,500 Lbs |
Alfa Laval WHPX 513
| Type: | 3-Phase; Self-Cleaning |
| G-Force: | 8,000 Gs |
| Capacity: | 60 GPM @ 180°F |
| Motor: | 15 HP |
| Power: | 460V; 60A |
| Size: | 6'×7'×7'H |
| Weight: | 4,500 Lbs |
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Picking the Right Centrifuge
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Ready to Recover Your Waste Oil?
Dolphin Centrifuge engineers will size the right waste oil centrifuge system for your volume, oil type, and processing temperature. Get a quote today.
Call us: (248) 522-2573 • sales@dolphincentrifuge.com