Keep the crankcase and lube oil tank ventilation of your large engines, turbomachines and compressors clean and efficient. A Hengst oil mist eliminator separates the oil mist from the air that the crankcase or lube oil tank has to vent, returns the oil to the circuit and lets clean air leave the vent, while a control-fan system holds a constant negative pressure on the system. That protects the environment, the turbocharger and the engine room, cuts lubricant loss and keeps the plant within its emission requirements. Multi-stage separation reaches 98 % efficiency, and the independently replaceable stages are sized to your ventilation flow. Also called an oil mist separator.
Request a system layout for your engine or turbomachine!
You can find oil mist separators for machine tools here.
Benefits
Long service intervals, low operating cost. Stable separation and independently replaceable stages mean you spend less on consumables and less on downtime over the life of the unit; the operating cost stays predictable instead of climbing as the filters age.
Simple, fast maintenance. Each filter stage can be adjusted or exchanged on its own, so a service visit touches only the stage that needs it rather than dismantling the whole eliminator.
Adaptable to your plant. Project-specific components can be added for open or closed circuits and for bypass solutions, so the eliminator fits the way your engine or plant is actually built, not the other way around.
Backed by our own filter know-how and global service. The coalescing filters come from Hengst's own production, and the worldwide service network keeps spare parts and support available wherever the plant runs. The same vertical depth supplies the matching filter elements through the Hengst gas turbine and turbomachinery filter range.
Oil Mist Eliminator Performance for Engines and Lube Oil Tanks at a Glance
| Separation efficiency | 98% for oil mist and particles |
| Air flow rates | 350 / 750 / 1,050 m³/h |
| Operating temperature | up to 80 °C |
| Electrical connection | 380 V, 50/60 Hz |
| Filter stages | Independently replaceable |
Get the spec sheet for the matching size!
System Components and Filter Stages
The eliminator is built as a multi-stage system, and each stage works on a different part of the job: coarse pre-separation, coalescing and fine filtration. Because the stages are independent, you replace only the stage that has reached its service limit rather than the whole unit, which keeps maintenance time and operating cost down.
A complete unit combines:
- pre-filter plates for the first stage of coarse filtration
- FogTex coalescence filter , which causes fine droplets to coalesce into larger ones and drip back
- LoTex special oleophobic filter for efficient oil separation
- AeroPlus fine filter element for filtration of the smallest oil aerosols
- Control fan a powerful fan that increases the exhaust volume and regulates the negative pressure
- Differential pressure/airflow controller that maintains a stable operating point even when the load on the stages changes
Not sure which size or circuit fits your machine?
Send us your specifications and Hengst will size the oil mist eliminator for your case.
How an Oil Mist Eliminator for Engines and Lube Oil Tanks Works
On rotating machinery (gas, diesel and dual-fuel engines, turbomachines, compressors, lube oil tanks and gearboxes), warm lube oil leaving the bearings is partly turned into a fine aerosol. That oil mist collects in the crankcase or lube oil tank and has to be vented. Without treatment, it leaves the vent as a visible, oily plume and the plant loses lubricant.
The oil mist eliminator sits in that vent line. Its coalescing filters merge the fine oil droplets into larger ones that drain back toward the circuit, while the particle stages hold back solid contamination. At the same time, the control fan and the differential-pressure controller maintain a constant slight negative pressure on the crankcase or lube oil tank. That supports lubrication and helps prevent oil leakage at the bearing seals.
The result is a simple, measurable one: a multi-stage coalescing eliminator returns the separated oil to the circuit and lets the ventilation air leave the vent at 98 % separation efficiency.
For the wider topic of crankcase ventilation, see our crankcase ventilation know-how page.
That's why customers trust Hengst
In-house Filter Elements: Coalescing filters developed and manufacturedin-house , not purchased from third parties.
Global service network: Spare parts and supportwherever the system is in operation.
Experience since 1958: Filtration technology across the entire Hengst Group.
In-houseengineering : Systems thatwetailor to yourspecific engine, turbomachinery, or plant .
Applications & Industries
The oil mist eliminator is used wherever rotating machinery has to vent oil-laden air from its lube oil system:
Sizing and Selection: Which Configuration Fits Your Machine?
Three factors decide the configuration. The first is the ventilation flow rate: the three sizes (350, 750 and 1,050 m³/h) are matched to how much air the crankcase or lube oil tank needs to vent. The second is the circuit concept: an open circuit vents the cleaned air, a closed circuit returns it, and a bypass can be added where the application calls for it. The third is the negative-pressure requirement on the lube oil tank or crankcase, which the control-fan and controller hold constant. Because engine and plant layouts differ, the exact configuration (size, circuit and any project-specific components) is set by Hengst application engineering for your case rather than picked from a fixed table.
Request sizing for your ventilation flow rate!
Our experts will help you choose the best solution for your application.
Filter Systems and Filter Elements: One Source
Hengst supplies both sides of the job. The complete oil mist separation system on this page belongs to the air intake filter systems world. The filter elements inside it, and the elements for gas turbines and turbomachinery more broadly, come from the Hengst gas turbine and turbomachinery filter range. Because the elements are developed and produced in-house, system and element are matched at the source. If you arrived here looking for replacement elements, you will find them in that range.
Looking for the replaceable filter elements rather than the complete system?
Gas turbine and turbomachinery filter range.
FAQ on Oil Mist Eliminators
What does an oil mist eliminator do?
An oil mist eliminator removes oil mist and particles from the ventilation air of an engine, turbomachine or oil tank before that air leaves the vent. On rotating machinery, warm lube oil at the bearings is partly turned into a fine aerosol that collects in the crankcase or lube oil tank. The eliminator captures that aerosol, returns the oil toward the circuit and lets clean air leave the vent. This protects the plant environment and the people working around the machine. It is also called an oil mist separator.
How does an oil mist eliminator work?
It sits in the vent line and works in stages. Coalescing filters merge the fine oil droplets into larger ones that drain back, while particle stages hold back solid contamination. A control fan moves the ventilation air, and a differential-pressure / volume-flow controller keeps the operating point stable as the stages load up. Together the fan and controller also maintain a constant slight negative pressure on the crankcase or lube oil tank, which supports lubrication and helps prevent oil leakage at the bearing seals.
What separation efficiency does the Hengst oil mist eliminator achieve?
The Hengst oil mist eliminator reaches 98 % separation efficiency for oil mist and particles. The multi-stage design (pre-separation, particle filtration and fine coalescing) is what holds that efficiency in steady operation rather than only when the filters are new.
Which flow rate or size should I choose?
The eliminator is offered in three flow rates (350, 750 and 1,050 m³/h) matched to how much air your crankcase or lube oil tank needs to vent. The right size depends on that ventilation flow, the circuit concept and the negative-pressure requirement of your machine. Hengst application engineering sizes the unit for your specific case, so you do not have to estimate it from a generic chart.
Can it be adapted to open, closed or bypass circuits?
Yes. Project-specific components can be integrated for open or closed circuits and for bypass solutions, so the eliminator suits the way your engine or plant is configured. This is set during the layout for your project rather than fixed in advance.
Is service and spare-part supply available worldwide?
Yes. Service and spare parts are backed by the worldwide Hengst service network, which matters because these engines and turbomachines run in plants around the world. The filter elements come from Hengst's own production, so replacement stages stay available and matched to the system.
Oil Mist Elemination at the Lubricating Oil Tank Vent
Talk to a Hengst application engineer about the ventilation of your engines and lube oil tanks, and get an oil mist eliminator configured for your engine or turbomachine.
