That’s Classified

Cost effective options for compressed air in classified areas

By: Michael Camber

A few posts back, we wrote about removing compressors from a bad environment for their health (away from excess heat, dust, etc.). This time we’ll talk about moving them for the safety of people. Specifically, we are talking about hazardous areas where the presence of flammable gases or liquids, combustible dusts or easily ignited fibers exist in sufficient concentrations to cause a fire or explosion, given a source of ignition (such as electricity running through a compressor).   

Obviously, this might apply to parts of (or entire) chemical, oil or gas processing plants.  But it could also apply in other industries we don’t think of as handling hazardous materials. Fine powders or fibers from grains, wood, etc. can create fire hazards. We’re not trying to raise the fear factor. This is not a common concern, and if it does apply in your plant, you are probably are already well aware.  

In the oil & gas and petrochemical markets, there are suppliers who specialize in engineering and modifying air compressor systems and other motor-driven equipment to be “explosion proof.” This gets very expensive, very fast. It also takes time for these systems to be designed, built, installed, and certified to operate. This is specialized work and these suppliers (rightfully) charge a premium for it.

A natural gas processing plant

In the case of a compressed air system, however, there may be an easy cost-saving alternative: Move it. Move it to another part of the plant that is not in the “classified area” and pipe the compressed air in. Usually, the air is not the source of risk. It’s the motor, starter and electrics. Sometimes it just takes a little out-of- the-box thinking to find another spot for the compressed air source. But sometimes there simply isn’t a safe place or enough space for the compressors somewhere else in the plant. In these cases, compressor system enclosures set outside at a safe distance are viable options. 

Compressed air production was moved a few hundred yards away

This solution presents the increased costs of packaging the air system up and of piping the air longer distances. But they may compare favorably to the engineered explosion-proof system. Further, they usually offer faster design, build, install, and commissioning. Not to mention lower maintenance costs by using standard compressed air equipment and less downtime when service is due (think about procedures to get outside personnel into restricted areas).

Weather-proof enclosure with complete compressed air system pre-installed.

Visit our website and download the white paper: Hazardous Area Classification Considerations for more on this subject and check out this ThingLink to see what one of these enclosures looks like on the inside.

Is it me, or is it hot in here?

By: Michael Camber

Later this month we are going to Cast Expo, the trade show for metal castings producers.  In talking to colleagues about foundries and their applications, it is clear that compressed air is as vital in this industry as it is to most manufacturers.  Unfortunately, while they rely on compressed air, the foundry environment is often horrible for air compressors and dryers.

In metal casting, the combination of high heat from molten metal and high loads of pervasive airborne particulate including silica, fly ash, and coke dust will almost certainly increase down time for maintenance and may reduce equipment life.  Filter changes, oil changes and cooler cleaning must all be done more frequently to keep the compressors running within acceptable temperature ranges.  Motors and electrical cabinets don’t do well with heat or particulate either (especially if it’s combustible). Further, high compressor discharge temperatures decrease the effectiveness of dryers downstream, resulting in more moisture in pneumatics. The stakes are high. One of our foundry customers calculates losses from downtime at $22,000 per hour. 

In some cases, the ambient temperature is simply too high for the compressors and dryers to work well, even with aggressive maintenance plans.  It’s not unheard of for compressor rooms in foundries to be 120°F.  For the health and longevity of the compressors, and continuity of operations, it’s best to place the compressed air equipment as far from these conditions as possible.   This is not always practical.  At the very least, it may require longer pipe runs, and if space isn’t available in another part of the plant, a new building may be necessary. 

Modular structure option at a Virginia foundry

Obviously, new construction gets pricey and time consuming.  Building design, permitting and construction, take time and attention.  An option is modular structures vs brick and mortar.  Depending on design, these can be weatherproof and well ventilated to suit the needs of compressors.  In some cases, the enclosures can be fabricated off site and delivered with the compressed air equipment pre-installed.  This saves time and money on installation and doesn’t disrupt operations on site.   It also takes less time to commission, and often doesn’t require construction permits.  We’ve had several customers take this path with great success. 

Whether building a new building, using pre-fabricated enclosures, or re-purposing existing space in the plant, careful attention to proper (temperature controlled) ventilation and dust control will be vital to compressed air system reliability.  Keeping maintenance costs low and extending compressor life will ultimately pay off with reduced downtime.   At $22,000 per hour, it’s worth the investment.