A Waste oil centrifuge separates water and solids from any type of waste oil. Flow through industrial centrifuges offers large processing capacity. High centrifugal force (up to 12,000 g) separates all free water and fine sediment (0.5µ). Continuous three-phase separation is the key to efficient separation of waste oils.
Three-phase separation means the separation of the three phases in contaminated oil. The 3 phase are: light phase – oil, heavy phase -water, and sludge.
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.
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 to separate the small particles.
Our industrial grade Waste Oil Centrifuges generate up to 12,000 g’s. Separation of finer solids from the contaminated oil needs higher g-force. Large scale processing of WVO is best handled by industrial centrifuges. These Alfa Laval disc stack centrifuges have a continuous flow-through design.
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. Customers who are seeking to process at least of few hundred gallons of WVO or any waste oil per day. Our ‘turn-key’ waste oil purification systems range from 500 Gal/Day to over 10,000 Gal/Day.
Waste Oil Decanters (for high sludge applications)
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 handles high levels of sludge (up to 40%) on a continuous basis. Alfa Laval decanters replace belt-presses and screw presses in many demanding high-sludge applications.
Waste Oil Filter versus Centrifuge
In this section, we 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. This is due to the ongoing cost of labor and material involved.
Consider a commercial used oil collector who wants to process 10,000 gallons per day. Their collection consists of WVO, UCO, Waste Oil and any other used oil.
The first step involves heating and settling to remove most free water. This requires significant tank volume with heating for the ‘heating and settling’ routine. Despite the time and heating cost, all free water is still not removed by this method.
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 a labor intensive process. Replacing and disposing filter media adds to cost and time. Cleaner oil requires finer mesh filters. This means frequent replacement of media, which means more material and labor costs.
The ‘finished product’ contains water. Water is removal requires adsorption or ‘boiling off’, which adds extra cost to the process.
The capital expense of centrifuge equipment is more compared to decanting and filtration. Payback period of a centrifuge system is short considering all costs. It is often in months depending on volume of oil processed.
Using Industrial Centrifuges for Waste Oil Recycling
Waste Oil Centrifuge – Process Flow Diagram for Industrial Scale Processing.
A decanter centrifuge is a heavy duty continuous de-sludging machine. It generates approximately 3000 times the force of gravity by centrifugal force. The decanter centrifuge processes incoming crude oil to remove all solids from 1/2″ down to 50 micron level in one pass.
The de-sludged oil and water is 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 fluid. Heating up 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 0.5 micron level.
This centrifuge machine continuously separates the water and intermittently ejects the separated solids. A PLC in the local control panel controls the entire process. It also controls the sludge ejection system.
The process illustrated and described above is ideal for commercial scale purification of waste oil. This is a continuous process with zero media and labor costs.
Advantages of Centrifuges Over Filters for Waste Oil
Total mechanical separation eliminates the need for filter media and labor costs.
Continuous separation without the downtime/labor associated with filter replacement.
High g-force allows the centrifuge to separate particles down to 0.5µ level.
A waste oil centrifuge will also separate all free water.