Dolphin Centrifuge

Machining Coolant Centrifuge | Operation, Benefits, Limitations, and Specs

Alfa Laval WSPX303 Coolant Tramp Oil Separator
Alfa Laval WSPX 303 Coolant Tramp Oil Separator

Table of Contents

What is Machining Coolant?

Industrial operations with machining operations such as metal cutting, grinding, milling, etc., use coolants for product consistency and operational durability. Therefore the quality of the machining coolant is an essential factor for efficient machining operations.

Many companies do not continually measure the contamination levels in their machining coolants. They have learned by trial and error that no problems will occur in the following machining stages by changing the coolant once a month or so.

Changing coolants just because they are dirty is an old-fashioned approach. It is also a messy and time-consuming task. With an industrial fluid centrifuge, you can control the contamination in the coolant tank.

There are many benefits to having a Clean Machining Coolant.

Coolant Centrifuge

Alfa Laval Industrial Centrifuges for Coolant Recovery
Alfa Laval WSPX 207 Coolant Centrifuge
Alfa Laval WSPX-207 Coolant Centrifuge Installation
Alfa Laval WSPX-207 Coolant Centrifuge Installation

A machining coolant centrifuge is an industrial disc centrifuge that effectively removes tramp oil and sediment from the coolant continuously. It is a mechanical separator that uses centrifugal force to separate water-based coolants from denser metal particles.


A machine coolant centrifuge exerts a very high centrifugal force of over 7,000 Gs on the contaminated coolant. As a result, the small metal particles (down to 1 micron) accumulate on the bowl wall from where they are self-ejected.

The lighter coolant (free of contaminants) exits the centrifuge continuously through the fluid outlet passage.

Advantages of a coolant centrifuge:

In summary, an industrial fluid centrifuge offers several advantages, especially for the larger-scale handling of cutting fluids.

Alfa Laval Industrial Centrifuge-Coolant
Alfa Laval Industrial Centrifuge-Coolant


Despite the advantages listed above, there are certain disadvantages to centrifuges for coolant recycling. The following are some of the limitations of centrifuges.


The following table summarizes the specifications of a typical, medium-capacity coolant centrifuge.

Centrifuge ModelAlfa Laval WSPX 307TGD-71G
Centrifuge TypeHigh-Speed, Self-Cleaning, Disc Stack
Coolant Processing Capacity28 GPM*
Bowl Speed8,375 RPM
Motor HP10 HP
Max. Solids32 Gal/ Hr
Weight1,500 Lbs
Dimensions30" x 52" x 54" (H)


Coolant centrifuges are available in different sizes, catering to customers with a small or large volume of water-based coolant to purify. The following table gives the nominal processing capacities of centrifuge models available from Dolphin Centrifuge.

Centrifuge ModelCapacity on CoolantSludge Handling*
Alfa Laval WSB 1043 GPMManual Clean
Alfa Laval WSPX 3033 GPMSelf-Cleaning
Alfa Laval MAB 20612 GPMManual Cleaning
Alfa Laval WSPX 20720 GPMSelf-Cleaning
Alfa Laval WSPX 30728 GPMSelf-Cleaning
Alfa Laval MOPX 21032 GPMSelf-Cleaning
Alfa Laval MAB 20940 GPMManual Clean
Alfa Laval WSPX 21350 GPMSelf-Cleaning
* Manual Clean = Operators need to stop and remove separated sludge.
Self-Cleaning = Centrifuge automatically ejects separated sludge without stoppage.


Will a centrifuge break the water based emulsified coolant?

No, a disc stack centrifuge does not separate water-based machining coolant into water and oil. The centrifuge separates the tramp oil and fine sediment without breaking the coolant emulsion.

Can a standard disc-stack centrifuge operate as a machine coolant centrifuge?

A standard disc-stack centrifuge is designed to separate majority oil (light phase) from minority water (heavy phase). A coolant recovery centrifuge feed constitution is the opposite.
There are specially designed centrifuges to separate the majority heavy (coolant) phase from the minority light (tramp oil) phase. Though a standard centrifuge can be converted to a coolant separation centrifuge, it requires modifying or replacing specific parts for the conversion.

Can a coolant centrifuge be adjusted to produce pure coolant or pure tramp oil?

Yes, the coolant centrifuge has some adjustment features that allow the user to tune the centrifuge to produce an absolutely clean coolant with small amounts of coolant with the tramp oil or vice versa.

Is the centrifuge effective for the separation of coolant at ambient temperature?

For water-based coolants, a coolant centrifuge can be quite effective if the coolant is at ambient temperature. However, heating the coolant increases the centrifuge's separation efficiency and could also help mitigate some of the bacterial growth in coolants. Read our article about pasteurizing machine coolant.

What is the consistency of the separated sediment ejected from a coolant centrifuge?

The separated sediment or sludge discharges from the centrifuge in the form of a thick paste (i.e. toothpaste) or a pumpable slurry, depending on the centrifuge setting and the type of centrifuge.

Is a coolant centrifuge a drop-in replacement for a belt-filter system?

Coolant centrifuges often replace belt filters. However, it is not a drop-in replacement due to the centrifuge's requirement of operating water which is easy to facilitate. The centrifuge system has a smaller footprint than a belt filter.

Can a coolant centrifuge operate at 220 Volts, single-phase power?

Standard coolant centrifuge modules are designed to operate on 460 Volt, 3-Phase power. However, we can design a coolant centrifuge system to operate on 220 Volts, 1-Phase power supply. It is worth noting that only small capacity centrifuges can operate on 220 Volts, Single phase power due to the motor size restrictions.

Can a disc stack centrifuge recovery synthetic or semi-synthetic coolant?

Yes, a coolant centrifuge separates water-based, synthetic, and semi-synthetic coolants with the same efficiency. There is no difference between the various coolants from a centrifuge perspective.

Alfa Laval WSB-104 Concentrator Coolant Centrifuge
Alfa Laval WSB-104 Concentrator Coolant Centrifuge

What is Tramp Oil?

Water-based coolants get contaminated with oil from hydraulic machinery, metal coating, machine tools, etc. This oil accumulates in the coolant forming a floating layer known as tramp oil.

The following list of common problems associated with tramp oil in coolants.

Tramp Oil Centrifuge

A tramp oil centrifuge is an industrial, 3-phase centrifuge designed to separate tramp oil from water-based coolants. It is a pass-through type of centrifuge that can separate the tramp oil from the coolants producing fresh, reusable machining coolant.


A high-speed, disc-stack centrifuge produces over 7,000 gravity forces to continuously separate the tramp oil and solid particles from the machining coolant. The high g-force forces the heavy metal sediment to the bowl wall, 

It also concentrates the light tramp oil in the rotating bowl’s center, which comes out of the center fluid passage; the clean coolant discharges through the outer fluid passage.


Centrifuge ModelAlfa Laval WSPX 303-TGP-34
Centrifuge TypeHigh-Speed, Self-Cleaning, Disc Stack
Lube Oil Capacity2 GPM
Coolant Capacity3 GPM*
Bowl Speed8,500 RPM
Motor HP3 HP
Voltage230 / 460; 3-Phase
Weight1,500 Lbs
Size36" x 48" x 50" (H)

Have you heard of pasteurizing machining coolant? It helps eliminate the bacteria in coolants. Read our detailed article about machining coolant recovery using a disc centrifuge and pasteurization.

Machining Coolant Purifier Centrifuge

Machining Coolant Purifier Centrifuge

Coolant Processing Module

Coolant Processing Module

Alfa Laval Centrifuges for Coolant Recovery

Alfa Laval Centrifuges for Coolant Recovery

Alfa Laval Tramp Oil Centrifuge

Alfa Laval Tramp Oil Centrifuge

Water-Based Machining Coolant Centrifuge

Water-Based Machining Coolant Centrifuge

Coolant Tramp Oil Centrifuge Cart

Coolant Tramp Oil Centrifuge Cart

Industrial Coolant Manual Clean Centrifuge

Industrial Coolant Manual Clean Centrifuge


To get more details email us or call us at (248) 522-2573

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