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.
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.