Industrial processes that combine lubricant with high-speed machine tools generate air pollution. The exact make-up of this pollution will vary significantly depending on the process, but is likely to consist of a complex mix of toxic contaminants – including oil, water, additives, metal slivers, bacteria and more.
Unsurprisingly, exposure to this cocktail of pollutants is detrimental to both human health and the wider environment. Contact between metalworking fluidsand the skin can result in dermatitis. And more severely, inhaling lubricant mist or smoke can lead to a range of respiratory illnesses, including industrial asthma and extrinsic allergic alveolitis. So, it’s vital to capture industrial pollution at source, the moment it is generated, to mitigate the risk to workers and other stakeholders.
The difficulty is that as machine tools spin faster to improve productivity, coolant delivery rates and pressures also increase. And as this happens, the risk of problems from oil mist and smoke grows too, which makes the job of removing such contaminant all the more important.
ScandMist is a range of industrial air cleaners that use a modular filter system to eliminate oil smoke, oil mist and emulsion mists for a clean and safe workshop environment. ScandMist removes fumes, emissions and other harmful by-products of metalworking processes at source with a three-stage filtration process. The clean air is returned directly to the workshop and exceeds international health and safety standards for exposure limits to metalworking fluids.
In fact, ScandMist exhaust air is a similar quality to that used in clinical applications, such as operating theaters. And with pre-filter efficiencies of greater than 95%, final filter life is measured in years rather than months. And that’s why ScandMist is best-in-class for filtration performance.
Particulate matter (PM) is microscopic solid or liquid airborne matter. It can be man-made or natural, but PM concentrations are typically greatest in areas of high industrial activity. And that’s why it’s important to understand the effect that PM can have on your workers’ health.
One in nine deaths globally are now associated with air pollution and PM is a major contributor to that number.
In fact, when public bodies, such as the World Health Organization, discuss air pollution they typically talk in terms of PM10, PM2.5 and PM1 — that is, particulate matter smaller than 10 μm, 2.5 μm and 1 μm respectively. And there’s good reason for this. Humans are adept at stopping particles larger than 10 μm from entering our bodies, but particulate smaller than this gets past our defences — and how far it travels depends on its size.
PM1, for example, passes through the walls of the lungs and enters the bloodstream; causing damage to our vital organs — including heart disease and various cancers.
High rotational speeds, increased process heat and high-pressure coolants mean machining processes are creating finer and finer aerosols. In 2006, a study by the German Social Accident Insurance Institute examined the pollution generated by a wide variety of machining processes using different coolants.
It found that the most dominant particulate created across all processes was PM1 (right).
Most oil mist eliminators are only effective against larger particulate, around 10 μm in diameter. But ScandMist is effective where it really counts — with particulate under one micron in diameter (PM1).
ScandMist combines oil coalescing filters with a final HEPA filter stage (class H13 to EN 1822) that provides 99.95 % efficiency against particulate 0.3 μm in diameter. With this level of filtration, the output air from ScandMist is clinically clean and likely to be of a much higher standard that that found outside your facility. That means safe air quality for your workers, and health and safety resolution for you.
The size of particulate generated by different processes and coolants may vary, but PM1 is by far the most common contaminant.
Some industrial filtration systems are essentially just extractors that take oil mist from the vicinity of the machine and vent it directly outside the facility. Not only is this bad for the environment, it is also bad for your wallet.
Venting scrubbed air from your workshop to the outside is the equivalent of driving with the heaters on full blast and the windows down. Your heating system is working hard to warm air that your filtration system then vents outside.
Because ScandMist’s exhaust air is so clean, it can be returned directly to the workshop. That means you can break the cycle of continually heating and expelling air outside. And that can have a dramatic impact on your heating costs.
And ScandMist is energy efficient in its operation too, employing EC motors that deliver maximum performance from a low energy demand — with closed-loop motor and fan speed control fitted as standard.
There is currently no international or EU standards for acceptable oil mist emission levels. But a marked increase in awareness of the impact to human health of ingesting sub-micron particles has led many countries to set their own limits. This is indicative of the changing picture across the rest of the world. As new evidence on the health impact of exposure to metalworking fluids emerges, responsible employers are taking steps to protect workers from industrial air pollution.
Oil mist exposure limits are based on the maximum permissible particle concentration levels in mg/m³. Levels set in Europe range between 0.2 mg/m³ in Switzerland, 1 mg/m³ in France and from 0.5 to 10 mg/m³ in Germany depending on the coolant.
ScandMist can help you stay compliant, both now and in the future. ScandMist exceeds all prescribed limits for exposure to metalworking fluids. And to make compliance easy, MANN+HUMMEL or our ScandMist Expert partners can survey your facility and provide a documented report of air quality at your site — recommending an optimized filter solution for even the most challenging environments.
Coalescing filter stage 1
In the first ScandMist stage, multiple layers of pleated media collect the oil or coolant, allowing it to drain to the base of the unit. The filter media does not absorb the oil, but rather coalesces the ever-increasing droplets until they are heavy enough to drain.
Contaminated air passes through the filter media where oil particles are attracted to the oleophobic fibres. The oil droplets continue to collide with the fibre and grow in mass. As the oil drop becomes bigger, it becomes heavy enough to fall against the air flow to the base of the ScandMist unit. Here, it can be collected or drained straight back to the machine tool sump.
Coalescing filter stage 2
The scrubbed air is then passed through a second coalescer at stage two, where the process is repeated. This second coalescer has a higher filtration efficiency than the initial stage, and captures the smaller oil particles that were not caught in stage one.
After this second filtration stage, the air is on average between 95 – 98 % free from oil mist.
Hepa filter stage 3
The third filtration stage is designed to completely clean the remaining air to a standard far higher than the surrounding ambient air.
Using a HEPA filter, this final stage ensures that fine, sub-micron particles — trace oil, smoke, bacteria, pollen and spores — are trapped and not allowed to return to the workshop.
ScandMist employs an H13 (to EN 1822) HEPA filter that provides 99.95 % efficiency at 0.3 μm. This means that in a workshop environment, effectively all hazardous particles are trapped and only clinically clean air is returned to the workshop.
Stages one and two remove 95% of emulsion and 98.5% of neat oil
@ 0.4 μm.
ScandMist high capacity platforms manage the oil mist emissions from a number of CNC machines, and are particularly popular in high-volume manufacturing environments that require filtration systems for entire production lines. These high capacity systems are designed to operate as part of a local ventilation system and can handle air flows from 6,000 m³/h to over 100,000 m³/h.
The real beauty of a ScandMist high capacity system lies in its simplicity; each is a completely custom design but consists of a selection of standard ScandMist units integrated together — with one common inlet and one common outlet. This modular approach allows us to quickly design a system that is a one off and tailored for your exact requirements, while using technology that’s well proven in the field.
Each ScandMist high capacity system is an integrated unit, with all the necessary components to plug in to your new or existing ventilation system. This can be configured to your requirements, but the typical ScandMist high capacity system will include:
- ScandMist multi-stage filtration stacks
- System control cabinet
- Frequency inverter
- High capacity fan & motor
- Silencing system
We provide a variety of accompanying equipment to ensure that your ScandMist unit or system is performing at the optimum level. These include frequency inverters to control the system pressure, oil pump boxes to collect the oil returned by the ScandMist unit, and pressure transmitters to enable the system to adapt to the current filter load conditions.
ScandMist also works with many products from other suppliers, so please contact us if you have any questions about compatibility.
Effective industrial ventilation is crucial in the highly-regulated manufacturing sector. But it’s a complicated topic, with different requirements depending on your process and geographical location.
To help you navigate this complexity, we provide a range of consultancy services focusing on industrial ventilation. We can come to your location and measure the efficiency of existing filtration systems. We will determine the air quality across your facility and design an oil mist system that’s tailored to your requirements.
We have a number of carefully-chosen partners that provide local distribution and commissioning of ScandMist systems. These ScandMist Experts are selected for their expertise and experience, and are only appointed following an extensive audit by MANN+HUMMEL to determine their credentials as ventilation engineers. Each Expert undertakes extensive product training to understand the ScandMist product range and optimization of motors, fans, control systems and filter choices for all possible applications.
Contact our experts directly: Info-oilsmoke(at)mann-hummel.com