Tag: particulate

Clean Room Certification – ISO 14644

Published on by Brian FarnoLeave a comment

The number of clean room certifications are vast and vary tremendously. ISO 14644 is the most used standard when looking at electronics and pharma manufacturing controlled environments. With this popularity, it has also undergone revisions within the past five years.

No matter the standard, each is divided into classes. The classes are rated from 1 to 9. The class identifies the maximum limit for particulate size and quantity per cubic meter of air. The chart below showcases the size and the quantity breakdown.

Cleanroom Classification Allowable Maximums.

ISO 9 as you can see is the loosest standard. This standard is equivalent to air quality within a city environment. These environments can fit a multitude of manufacturing and are some of the easiest to achieve and abide by. The opposite end of the spectrum, ISO 1 is the strictest and hardest to maintain. There are three main factors when designing for a clean room. These are surfaces, airflow, and employee access.

When selecting surfaces that will be within the environment it is best to choose a surface that will hold up to the level of use as well as not be damaged by the cleaners or solvents being used to ensure the surface is clean. This should carry over into part fixturing and even machine materials of construction as well. This is not always easy and should be a design element to the process and environment.

Airflow within the room is what helps maintain the concentration levels of particulates. Generally, a clean room is positively pressurized to where the pressure within the room is higher than that outside of the room. This results in a positive air exchange, generally this is provided by the HVAC system. Having a system that does not recirculate the air from inside of the room and a substantial filtration system is key. Another type of airflow that can be found within these environments is a blowoff operation for the part or process. When installing a blowoff within a clean room environment it should be confirmed that the materials of construction are compatible with the environment and cleaning processes and that the airflow will not be introducing particulate into the environment which can result in contamination.

Lastly, employee access should be limited to those employees who are trained and necessary to be within the environment. Sometimes if an employee wears the wrong type of deodorant it can effect an entire environment. Even the wrong type of clothing or soap can alter the state of an environment, let alone using a blowoff incorrectly or bringing the incorrect cleaner inside the cleanroom. Access to these areas should be limited and individuals should be well trained to meet the demands of the clean room.

If you would like to discuss your production environment or blowoff application within a clean room, please contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Compressed Air Purity Classes & ISO 8573-1. What Does it Mean for You?

Published on by Russ BowmanLeave a comment

The compressed air coming directly from your air compressor will usually require further treatment & preparation before it can be used. It’ll contain particulate matter, moisture, and hydrocarbons that the intake filter won’t remove…remember, it’s there to protect the compressor itself against damage from larger particulate. Smaller particulate and other contaminants that can affect air operated products & tools will still need to be addressed, after compression. The degree to which this additional treatment is necessary is dictated by what you’re using your compressed air for.

ISO 8573-1:2010 – Compressed air – Part 1: Contaminants and Purity Classes quantifies the quality of the air according to three properties, into different classes:

Per the descriptions above, here are the criteria by which compressed air purity is classified in these three categories. Certain applications can call for different classes for these three categories (more on that in a minute).
  • Maximum particle size & concentration of solid contaminants. These can come from rust on the inside of the distribution piping, particulate generated by wear of air system components, and atmospheric contamination that the compressor’s intake filter doesn’t catch.
  • Maximum pressure dew point. No matter where your compressor is located, the air it pulls in contains some amount of water vapor. Dew point is the temperature at which it will condense at a given pressure. As long as the compressed air temperature is above that dew point, there won’t be any water (in liquid form) in it.
  • Maximum oil content. This most often is due to carryover from oil lubricated compressors, but can come from atmospheric oil (or other hydrocarbon) vapor drawn into the compressor’s intake.

So…what does this mean to you, relating to your use of compressed air? Well, it largely comes down to the nature of your application. Whatever is in your compressed air supply will be in contact with whatever the air comes in contact with. If a machinist is using a Safety Air Gun to blow chips & coolant from machined parts, they’re not going to be particularly concerned with this specification from a regulatory standpoint. If those parts are going straight from the machine shop to a paint booth, they’re certainly going to want to use air that’s free of particulate, moisture, and oil. All of those things will, quite noticeably, affect the quality of the painted finish. Filter Separators and Oil Removal Filters installed at the point of use will take care of that. A case could be made for a purity specification and regular testing of their compressed air, but this really just falls under the confines of good engineering practice.

Compressed air use in applications where it can come in contact with food or beverages intended for consumption (by people AND animals, according to the Federal Food, Drug, and Cosmetic Act) is considered a critical factor for cleanliness. They reference guidelines from the British Compressed Air Society (BCAS) to specify purity classes for both direct and indirect contact with food and beverage products:

Direct contact requires testing and compliance to Class 2:2:1 per the above table means:

  • Particulate Class 2 – particle concentration, by particle size, in concentrations no greater than:
    • 400,000 particles sized 0.1-0.5 microns, per cubic meter
    • 6,000 particles sized 0.5-1.0 microns, per cubic meter
    • 100 particles sizes 1.0-5.0 microns, per cubic meter
  • Maximum pressure dew point Class 2 – vapor pressure dew point must be less than 40°F (40°C) at the maximum pressure of the compressed air system.
  • Oil content Class 1 – concentration must be less that 0.001 milligrams per cubic meter

Examples of direct contact applicable to the use of EXAIR Engineered Compressed Air Products include blowing air for cooling, moisture removal, coating layer distribution, etc., of unpackaged food product.

EXAIR Stainless Steel Super Air Knives are popular in food processing applications (left to right): removing excess moisture prior to flash freezing of fish filets, preventing clumping while packaging shredded cheese, and (my personal favorite) ensuring a consistent and even glazing of fresh, delicious doughnuts.

Line Vac Air Operated Conveyors and Vortex Tubes are also used in direct contact applications in the food industry:

316SS Threaded Line Vac conveys bulk grain in a distillery (left). Vortex Tube rapidly sets melted chocolate in a mold (right).

Indirect contact is slightly (but JUST slightly) less restrictive: those are Class 2.4.2. Particulate and oil content classes remain the same, but dew point can be as high as 37°F (3°C). This is where the air the air is coming into contact not with the consumable product itself, but, for example, the packaging or container:

Atomizing Spray Nozzles rinse bottles prior to labeling (left), 1″ Flat Super Air Nozzle blows off label to ensure proper scanning by sensor (center), Line Vac conveys canned goods (right).

EXAIR Corporation is committed to helping you get the most out of our products – and your compressed air system. If you have questions, I can talk about compressed air all day – and oftentimes I do! Let’s talk.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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ISO 8573-1 Chart by Compressed Air Best Practice.

How To Rebuild An Automatic Drain Filter Separator

Published on by Russ BowmanLeave a comment

Get the most out of your compressed air operated products by keeping up with filter maintenance.  Maintaining a filter separator ranges from a simple filter element replacement to repairing or replacing broken parts. Here’s a video showing how to rebuild an EXAIR Automatic Drain Filter Separator if corrective maintenance is needed. 

If you have any questions, give me a call.

Russ Bowman, CCASS

 

 

Application Engineer
EXAIR Corporation
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Compressed Air Quality Classes – ISO 8573-1

Published on by Jordan T ShouseLeave a comment

ISO 8573-1:2010 is the international standard for Air Quality Classes. It lays the ground rules for acceptable levels of pollutants, particulate, moisture, and oil in a compressed air source. 

Image Courtesy of  the Compressed Air Challenge

Though the standard has detailed standards for maximum particle size, maximum pressure dew point and maximum oil content for different industries and/or environments (see Slide show above) we can generalize a bit and express the levels of air quality like this:

Plant Air – general plant compressed air used for air tools, nozzles etc.
Instrument Air – found in laboratories, paint and powder coat booths, used for climate control.
Process Air – used in food and pharmaceutical applications, electronics applications.
Breathing Air – used for breathing respirators, breathing tanks and hospital air systems.

Achieving the different levels of air quality can be done with 3 basic types of filtration.
     1. Particulate – a filter element removes particles larger than the opening in the filter material. Typically done with particles greater than 1 micron.
     2. Coalescing – use different methods to capture the particles; 1) direct interception – works like a sieve, 2) Inertial impaction – collision with filter media fibers, 3) Diffusion – particles travel in a spiral motion and are captured in the filter media.
     3. Adsorption – the filter element holds the contaminants by molecular adhesion.

Filters
EXAIR FILTER SEPARATORS

The higher the class your air needs to be the more of these filtration methods you will use. Adsorption will remove more and finer particles than a simple particulate filter. And many applications will use a combination of these methods.

EXAIR products, all of which need a source of “clean, dry air” will operate very well utilizing a source of plant air and only a particulate filter. Your process, dictate if you need to supply additional filtration methods for better air quality. For example, an automotive plant using compressed air to blow parts off will not need the kind of filtration a food handling facility will need while blowing a food product off. If you are using a lubricated compressor or have lubricant in your compressed air lines from another source, you will want to use a coalescing oil removal filter.

EXAIR stocks 5 micron particulate filters which are properly sized for each individual product as an option for our customers if they choose. We also stock coalescing oil removal filters for customers who may need to remove oil from the air. Replacement filter elements are also available and should be replaced at least twice a year, depending on the quality of your air.

Oil Removal Filter
EXAIR Oil Removal Filter

Remember to ask about filtration if you have any concerns about your air quality. We can assist in sizing up the proper filters to get the air quality we recommend for proper operation and longevity of our products. 

If you would like to see how we might be able to improve your process or provide a solution for valuable savings, please contact one of our Application Engineers.

Jordan Shouse
Application Engineer
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Image Courtesy of  the Compressed Air Challenge