Contec oil mist separators
Effective oil mist extraction and filtration
In 1987, Contec developed and used the first oil mist separator. The in-house invention and the filter technology it used remain the idea behind aerosol filtration in lubricating oil systems. Unlike simple filters or separators, this technology frees 99.98% of contaminated air from environmentally harmful oil aerosols and returns the filtrate to the compressor or turbine circuit as high-quality oil. Contec oil mist separators received an environmental technology prize in 1990.
Contec oil mist separators can be used in turbine lubricating oil tanks, fluid grinding systems, vacuum pumps, steel test rigs, rotary presses, turbo-compressors, large-scale compressors, crank shaft gears or hydro-erosive grinding systems.
Contec addressed the complexity of the task and process and integrated those insights into the product solution. The result is a reliable system that gives us absolute operational reliability.
Pavan Kshirsagar, Projects Team Leader
ATLAS COPCO Ltd. – Gas & Process Application
We invented the oil mist separator. We know what is important for its design.
The oil mist extraction design is generally system-specific and requires years of technical experience. The modular system allows simple adaptation to customer-specific systems.
How do oil mist separators work?
Have a look at the animation to see the interior of a COMS (Contec Oil Mist Separator). How are oil aerosols separated and fed back into the system, where are the filter elements and how are they replaced?
Technical details of the Contec oil mist separator series
Lubrication oil systems for gas, steam and water turbines, turbo-compressors and turbo-machinery generate smoke with high oil mist content, with fine oil droplets reaching emission values of 300-400 mg/m³ and even more.
In large workshops and machinery buildings, turbo-machinery, gears, turbines and compressor are used to produce power or compressed air. They often pollute the workplace and the environment more generally with oil mist from the lubricating oil tank. Legal provisions for workplaces limit this oil mist concentration, but these limits can often not be adhered to. The best that can be done is route the oil-laden exhaust air through complex pipe systems in the hall ceiling to the outside, which only shifts the problem instead of solving it.
High-performance filters with elements made of fiberglass fleece have proven themselves in oil separation from rotary press exhaust air wherever the existing system pressure, or overpressure generated by the machine itself, is sufficient. But for many machines, especially those for special applications or operating under unfavorable conditions, existing overpressure is not sufficient.
Such cases require a blower to extract oil-laden air and route it through the filter. Side channel compressors have proven effective for such applications: they are reliable, cost-effective and have an optimal throughput-pressure ratio. The filter elements are designed specifically for this application. They are 99.98% efficient with droplets of 0.1 µm, the pressure resistance is about 60 mbar. This means that the air released to the environment is much cleaner than the German Technical Instructions on Air Quality Control (TA Luft) prescribes. The separators fulfill all legal requirements and recapture high-quality lubricating oil that also usually contains expensive additives.
The oil mist separator essentially consists of the side channel compressor and the filter housing with filter elements. The side channel compressor generates a controllable negative pressure to extract the oil-laden air. The air flows through the standpipe in the intermediate space in the filter housing, disperses and flows from there through the filter elements. This prevents leaks and oil mist escaping from bearing points, shaft feed-throughs and crankshaft ventilation passages. The filter element's long service life and the automatic oil return mean very low maintenance.
The core of the COMS (Contec oil mist separator) is the specially developed glass fiber filter elements. The two-layer design with its incorporated reinforcing fabric optimizes the coalescing effect and ensures that oil separation remains consistently high. The efficiency (99.98% for droplets of 0.1 µm) is much less than the emissions limits set in TA Luft. This is one reason why our oil mist separators have been awarded the environmental technology prize.
The very compact design of Contec oil mist separators allows them to be used even under difficult installation conditions where space is tight.
The side channel compressor generates negative pressure to extract the oil-laden air from the lubricating oil tank. The air flows through the intake pipe into the filter-housing cavity, where it disperses to the filter elements and is fed through them. The fine oil aerosols in the air are retained on the filter surfaces, collected and finally returned to the machine. 99.98% of all oil droplets are separated from the air. The same is true of contamination particles. The exhaust air thus filtered is, technically speaking, absolutely dry and clean and can remain in the factory without hazard. Levels of contamination are far below the TA Luft limits. Complex, expensive exhaust ducts are a thing of the past.
The filter elements' long service life (usually at least a year) and the automatic return of the oil gives the lubricating oil system a low-maintenance feature. The quick-connect fasteners on the cover, or the swiveling cover (optional), make the filter elements quick and easy to replace.
The filter elements used in Contec oil mist separators (COMS) are developed specifically for cleaning oily gases in the exhaust air of rotating machinery. It is just here that high-performance filters with fiberglass fleece elements have proven themselves. The filter elements are disposable. They deliver exceptional filtration efficiency with low pressure losses and long service life.
The two-layer design consists of an integrated supporting inner layer between two bound outer layers. This design has outstanding burst strength, optimizes droplet coalescence and guarantees consistently high oil aerosol separation. Since the filter elements consist of multiple layers, they prevent oil mist that has already been extracted by the elements from being blown back.
The filter element composition is completely inert to all lubricants and practically resistant to all chemicals used in such machines as wheel gears, gas and steam turbines, turbo engines and compressors. The filter elements are 99.98% efficient for droplets of up to 0.1 μm, so they make the air much cleaner than the German Technical Instructions on Air Quality Control (TA Luft) prescribe.
COMS is a registered trademark of the Contec oil mist separator division and stands for Contec Oil Mist Separators.
Contec invented the world's first oil mist separator in 1987. The invention can be credited to engineer Ricard Neuhausen.
Oil mist separators filter oil mist out of the air. Polluted air or a toxic mixture of gases arises when rapidly rotating machine parts are immersed in an oil bath or are constantly wetted with oil for lubrication. This is the case for machines such as wheel gears, gas and steam turbines, turbo engines and compressors used in industry to generate power or compressed air. The oil-gas mixture must be discharged from the machines to prevent oil mist (from the lubricating system) from escaping through the bearings.
Contec oil mist separators essentially consist of a side channel compressor and a filter housing with filter elements. The side channel compressor generates negative pressure to extract the oil-laden air from the lubricating oil tank. The air flows through the intake pipe into the filter housing air distribution panel, where it is distributed to the filter elements and fed through them. The fine oil aerosols in the air are retained in the depths of the filter, collected and finally returned to the machine. The exhaust air thus filtered is, technically speaking, absolutely dry and clean and can remain in the plant without hazard.
Yes, which is why maximum pollution values for emission reduction have been established by law. The values were established in the first general administrative regulation for the German Pollution Control Act (Bundes-Immissionsschutzgesetz) of 27/2/1986 – Technical Instructions on Air Quality Control (Technische Anleitung zur Reinhaltung der Luft or TA Luft). They are governed by the German regulation on large combustion, gas turbine and internal combustion engine plants (Verordnung über Großfeuerungs- Gasturbinen- und Verbrennungsmotoranlagen). This limits the residual oil content of exhaust air to no more than 20 mg per 1 m³ of air, for instance. The emission limits are according to the size and power of the plant in question, the type of fuel and the composition of the gases separated. For many lubricating oils, safety concerns lead to the imposition of a maximum workplace concentration of 5 mg/m³.
Contec oil mist separators can filter oil mist at 99.99% efficiency, eliminating all droplets larger than 0.1 μ. This means that the air discharged into the environment is much cleaner than the German Technical Instructions on Air Quality Control (TA Luft) prescribe. The separators thus fulfill all legal requirements and reliably recapture high-quality lubricating oil, which also usually contains expensive additives. The separated and recovered oil is absolutely clean. It can be fed back through the oil recirculation system into the oil tank without any worries.
The filter elements' long service life and the automatic oil recirculation give the system a low-maintenance design. The longer the system is in operation, the more the filter elements are saturated, including with solid particles. This clogs the pores, increasing the filter's pressure resistance (differential pressure). Filter element condition can be ascertained with a negative pressure gauge. If the COMS filter system is unable to maintain the desired negative pressure in the lubricating oil tank (usually between -10 and -5 mbar), the filter elements should be replaced. The quick-connect fasteners and the swiveling cover (optional) make the filter elements easy to replace. The filter elements are self-sealing and can be easily tightened to the housing with the screw caps on the integrated drawbar.
COMS oil mist separator areas of use range from lubricating oil tanks in gas, steam and water turbines to compressors, gas and diesel engines, vacuum pumps and generators. They are is use in power plants, refineries, LNG terminals and turbine manufacturing plants, for example.
Ultimately, they can, and usually must, be used anywhere rotating machinery is lubricated with oil.