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Oil
Mist Eliminators
Large volumes of
lubricating oil are necessary to cool and protect the internal working
surfaces of rotating machinery. These conditions can create an oil mist
has traditionally been vented to atmosphere. Vokes Oil Mist Eliminators
are designed to capture this mist to help meet increasingly demanding
environmental and safety legislation. Failure to deal with oil mist
can in worst cases represent a significant explosion hazard or, at the
very least, the oil can condense on surfaces to subsequently attract
dirt.
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Available
Ranges and Applications
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| Vokes
MM / MMF |
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- Diesel
engines - Crankcase breathers
- Gas turbines
- Gland vents, Lube oil tank vents
- Steam turbines
- Lube oil tank vents
- Compressors
- Glands
- Gearboxes
- Vents
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What is Oil Mist
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Oil within a machine
is subjected to high temperatures and pressures during operation, which
can result in the creation of oil mist. The mist typically consists
of oil droplets ranging in size from 10µm down to 0.03µm
and when vented into the atmosphere is normally visible as a blue-white
smoke.
Vokes has researched
the factors influencing oil mist emissions with the aim of satisfying
the ever evolving and tightening environmental legislation that frequently
refers to 'no visible emissions'. We have developed an efficient and
cost effective solution to oil mist control.
Vokes Oil Mist Eliminators
are available for airflow rates from 12m³/h (7cfm) to 4000m³/h
(2330 cfm), selection of which type depends on application and whether
a back pressure is acceptable within the machine.
Principles of
Oil Mist Elimination
Vokes Oil Mist Eliminator
cartridges remove entrained oil by a coalescing process. The cartridge
contains an oleophilic (oil attracting) media which is designed to maximise
oil removal while minimising differential pressures.
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Droplet
Formation and Breakdown
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The contaminated
air stream is directed through specially developed Vokes cartridges,
which consist of multiple layers of dense coalescing media. The
oil attracting characteristics of the media ensures that oil droplets
passing through the cartridge are attracted to the fine fibres.
The depth of the media ensures that each oil droplet will find
a fibre, even though the space between the fibres may be larger
than the diameter of the oil droplet itself. Further droplets
attach themselves to the fibres, joining together to form larger
droplets with the continued removal of oil from the air stream.
Eventually, either due to the force of gravity or the velocity
of the air stream, these larger droplets breakaway and drain through
the coalescer and eventually accumulate as free oil at the bottom
of the eliminator.
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Element Saturation
and Equilibrium
During
operation oil mist eliminator elements reach a state of saturation or
equilibrium. This is the point at which the rate of oil removed from
the air stream equals the rate at which it is drained away. Saturation
is the normal operating condition and will continue until the cartridge
is blocked by particulate contaminants released by the machine into
the oil mist stream.
Benefits
of Efficient Control
The need
to vent lubricating oil systems to the atmosphere and the resulting
plume of oil mist has long been recognised as a source of pollution.
Although in the past it has been acceptable to simply control
oil mist, legislation in many countries now defines control
as 'no visible emissions'. While recognising the need to meet
Environmental Protection & Safety legislation, the efficient
control of oil mist can also reduce operating costs and improve
the reliability of equipment.
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'No Visible
Emissions'
To meet the objective of 'no visible emissions' all VOKES Oil
Mist Eliminator cartridges are designed to a high performance
specification with an initial efficiency of 99.98% @ 0.3µm.
Environmental
Legislation
Increasingly stringent environmental legislation has come about
as a result of public concern over the effects of emissions from
industrial sources. VOKES Oil Mist Eliminators remove potential
health hazards, minimise unpleasant odours and generally improve
the quality of the environment.
Health
& Safety Legislation
The control of oil mist emissions with a VOKES Oil Mist Eliminator
is good health and safety practice, avoiding the accumulation
of oil deposits inside and outside the installation. Oil deposits
are a potential fire risk, especially adjacent to exhaust pipes
and unprotected electrical equipment, and a hazard to people using
walkways. Mist generated from a flammable oil is itself an explosion
hazard.
Efficient
Operation & Cost Savings
The operating efficiency of diesel engines and turbines is reduced
when oil mist is sucked back into the air intakes. This can block
the air filters and coat the internal surfaces with oil. A Vokes
Oil Mist Eliminator improves the air quality in the vicinity of
the air intake, which in turn helps to maintain power output and
reduces the frequency of air filter replacement as a result of
oil fouling.
Thousands
of litres of oil can be lost from an installation over a period
of a year due to oil mist emissions. The cost of replacement oil
can be greatly reduced by returning the recovered oil back to
the system.
A Vokes Oil
Mist Eliminator helps to reduce general maintenance costs by recovering
oil, which would otherwise cause unsightly staining on buildings
and in engine rooms. The absence of oil mist also helps to improve
the reliability of electrical and electronic equipment, by avoiding
the accumulation of a fine oil film on critical components.
Selecting
a Vokes Oil Mist Eliminator reduces the capital cost of an installation
by minimising the need for complex venting and pipework installations. |
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| Available
Documents |
Acrobat
Version |
| Power Station OME
Brochure |
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