There are many myths about compressed air that permeate the industry. Here are some of them:
Compressed Air is Expensive and Inefficient. This seems to be the current myth, In the past the prevailing myth was that it’s free. Neither is correct. If used properly in a correctly designed system it can be the most cost-effective and efficient compared to alternatives. As an example, there actually have been systems that changed to compressed air from blowers for drying applications because the blower was not strong enough (compressed air worked better). With blowers the production line slowed and quality went down. Not only that but the maintenance costs increased. The lower energy costs of a blower were not enough to compensate for reduced output and the savings in energy was not as much as thought because the blower had to be operated constantly while the compressed air could be set on and off as required, Also, the compressed air pressure was only at 60 PSI so the energy cost difference was not nearly what was anticipated. When considering compressed air against other sources of energy, you need to consider many things – not just energy cost – actual pressure needed, if on-off operation can be done, maintenance and other factors.
The Higher the Compressor Pressure the Better. This is definitely wrong. Raising pressure to the system at the compressor will require more power. Pressure problems are best solved at the point of use where they exist, and by addressing leaks and pressure drops in the system and not with more power in the compressor room. In fact, raising the pressure can aggravate a situation if there are many leaks as all it will do is cause more air to be leaked away from the system.
The Drier the Air the better. The key factor here is if the compressed air used will fall below the dew point and develop water in the system. That is what must be considered. Sometimes getting drier air can cost more energy due to Dryer purging and other Dryer operation costs. It depends very much on the factory environment and application as to how dry the air needs to be. In some cases all that is needed is to remove loose moisture in the air which filters and/or separators can accomplish.
Compressed Air is Dirty. In a badly designed system, and badly maintained system it can be. But it does not have to be. Properly sized and maintained Dryers and Filters can provide the clean compressed air needed. Oil vapor as well as moisture are natural by products in the use of compressed air but can be controlled with proper filtration and care.
Reducing the Compressor Operating Pressure will Save Energy. How far pressure is reduced will determine the savings at the compressor, but if reduced too much the less stable and reliable the system can become. The first time production is interrupted because of too low a pressure in the system, the operating pressure will just be returned to previous levels and any savings anticipated will disappear. After all, you have to keep production running!
Fixing Some Air Leaks will Save a Lot of Energy. Compressed air leaks are a major source of wasted energy. Air leaks can also cause pressure drop in the system. Once some major leaks are fixed, the pressure in the system will rise and in fact, the remaining leaks will now leak more because of the higher pressure in the system. So savings are seen only after a majority of system leaks are repaired. A proper leak detection and repair program needs to be in p.lace rather than an ad hoc approach to fixing compressed air leaks
Nex Flow Air Products Corp. manufacturers compressed air products for blow off, drying, cleaning, cooling, and moving as well as accessories to improve your compressed air system.