Oil Mist Extraction

What is Oil Mist?

Oil mist is created when metalworking fluids are sprayed by machine tools to help lubricate the tool or keep metal components cool. Oil mist is atomised oil resulting in dangerous airbourne particles. Oil mist is generated when oil or coolant is sprayed onto machine parts to aid the manufacturing process - often using compressed air to atomise the oil.

Manufacturers initially used water to cool the surface of the metal and then moved on to other types of lubrication, including lard, as speeds and efficiencies increased. Today’s modern machine shops use a variety of fluids depending on the purpose of the application.

There are four basic types of metalworking fluids used to keep metal cool during manufacturing processes: Straight Oils, also known as ‘cutting’ or ‘neat’ oils; Soluble Oils; Semi-synthetic Fluids and Synthetic Fluids. Each has its own specific properties and is more suitable in certain applications, but they all have one thing in common – they all generate airborne mist particles when sprayed.

Industries where oil mist is commonly generated include automotive, aerospace, medical device manufacturing, power generation and general precision machining. In all instances oil mist is considered to be a danger to health and as such needs to be controlled in the workplace, enforceable by law (COSHH Regulations).

What is an oil mist extractor?

An oil mist extractor is a piece of machinery which is used to remove oil mist at source before it has an opportunity to escape into the machine shop. Oil mist extractors are connected to machine tools using ducting to extract the contaminated air from the machine’s enclosure. The polluted air is pushed through a filter and clean air is exhausted to atmosphere or returned to the machine shop.

Why do I need oil mist extraction?

Oil mist is a hazard to human health and can increase susceptibility to several types of cancer as well as causing other health problems such as extrinsic allergic alveolitis (also known as Hypersensitivity Pneumonitis), contact dermatitis, asthma, bronchitis and lung fibrosis to name but a few.

Oil mist particles which are larger than 3.5 microns in size are separated in the nose and throat, whilst particles smaller than 1 micron are absorbed into the bloodstream. Particles between these sizes are retained by the throat, bronchial tubes and lungs, causing a variety of occupational diseases. To put this into perspective, the diameter of an average human hair is between 10 and 50 microns.

In the UK, COSHH (Control of Substances Hazardous to Health) Regulations 2002 require employers to reduce exposure to oil mist particles to ‘as low as reasonably practicable’ – ALARP. In the majority of cases this means using an oil mist extraction system as a key control measure.

Oil mist is also a fire risk and is flammable if exposed to a source of ignition. Our oil mist filters remove this risk by capturing and containing the oil within the filter before returning clean air to your workshop.

Oil mist escaping from your process can also settle on floors and other surfaces and can cause slips and falls if droplets are allowed to build up on surfaces where workers walk. Accumulation of oil mist on sensitive electronic apparatus can also cause equipment to fail, interrupting production and resulting in costly downtime.

How does an oil mist extractor work?

Oil mist extractors work using different types of technology depending on the manufacturer of the oil mist filter. There are currently three methods used to collect and remove oil mist generated by machine tools; static filter media, electrostatic and rotating filter units that use centrifugal force - each method has its own attributes.

• Static filter media

  Units that use static filter media are generally used for high-volume applications and widely used in centralised extraction systems. Air is drawn into the unit, heavier particles fall to the bottom and are pumped out for collection or re-use. Polluted air then travels up through the first filter cassette which traps smaller particles and if necessary, a further filtration process can be included in particularly demanding applications.

• Electrostatic precipitators

  Electrostatic precipitators use an ioniser that produces an electro static charge which collects and traps air pollutants on an internal baffle plate. This type of filter is very effective for welding fume and smoke applications, but not so good for oil mist as the mist can build up on the plates quite quickly. This reduces the amount of airborne contaminants that are effectively captured so the units need regular cleaning to ensure they are operating efficiently.

• Centrifugal force

  Centrifugal force is a proven method which is trusted by some of the world’s leading manufacturers to keep the air in their machine shops clean. A perforated drum with specially designed vanes rotates at high speed. Oil mist is drawn into the unit and impacts on the vanes at high velocity.

  Special drum pads assist the coalescing process and filter out stray particles. Centrifugal force pushes oil to the unit’s outer case where it drains back to the machine for re-use or collection and clean air is returned to the workshop through the top of the unit.

How much does an oil mist extraction system cost?

The cost of oil mist extraction systems varies depending on which type of technology is used – this will depend on the specific application and customer requirements. Filtermist supplies a wide range of oil mist extraction systems to suit all budgets. Please contact our team for more details.

Oil mist extraction applications

Oil mist extraction systems are used in a wide range of manufacturing applications including milling, turning, drilling, cutting, grinding, parts washing, linishing, finishing and EDM/spark erosion. Oil mist filters are fitted to CNC machine tools such as machining centres, lathes, grinders, saws, parts washers and many more.

Can oil mist extraction save me money?

Did you know that as well as reducing the health hazards associated with exposure to mist particles, using Filtermist oil mist collectors can also save you money? Using effective oil mist extraction can:

• Protect machine tool control panels from unnecessary breakdowns due to oil ingression
• Prevent unnecessary downtime
• Reduce costs for spare parts and maintenance charges
• Increase the time between maintenance visits for Machine Tools therefore lowering costs
• Reduce the cost of worker sick leave and absence cover
• Lower wastage costs by keeping the machine spindle working well so that the manufactured part is within required tolerances
• Reduce maintenance time on the filter unit compared with other technologies = lower labour costs
• Reduce whole lifetime costs as our quality products won’t need replacing as quickly as an inferior alternative
• Return coolant to the machine - reducing coolant costs
• Lower cleaning bills
• Help to win new business with high standards of cleanliness in production facilities
• Retain customers – reducing the costs associated with winning new business
• Help to recruit and retain high-calibre employees - minimising high recruitment costs