This might be the first time today that you have thought about your medical air dryers, but I bet they have been used already today. Dryers are a very important part of your medical air system. Many medical air systems have been compromised and are in need of repair to eliminate excess moisture present.
There are two different dryer technologies commonly used in facilities today, refrigerated dryers, and desiccant dryers. While both have been used extensively, most new systems installed today are of the desiccant variety, and new breakthroughs in medical air drying technology are improving upon the desiccant process. Desiccant dryers are an improvement on the refrigerated dryer in that you do not have to contend with the downside of “freezing” compressed air below 32 degrees. Also, refrigerated dryers tend to recirculate stagnant water from the system causing an increased dew point, and thus a dew point alarm above 35 degrees. Since the most widely used refrigerated medical air dryer is non cycling, the facility has to contend with the dryer running all of the time, regardless of flow usage. This means higher energy costs, that will ensue due to the dryer purging water constantly, even during off peak hours in the facility. With so many facilities looking for “green” systems, a refrigerated dryer draining power and spitting water does not fit into a more conservational engineering plan.
Desiccant dryers use a synthetic material to absorb moisture from the compressed air, (think of it as a bunch of little balls in a cylinder). This absorbent material is able to rid the air of moisture without freezing it and without producing condensation that will appear on the outside of the dryer tower. One of the drawbacks to desiccant dryers in the past was that 15% of the compressed air was purged along with the moisture. Today some medical air systems offer zero loss electronic discharge drains that save the compressed air from being purged and wasted, preventing the dryer from ramping back up to compensate for that lost air. New desiccant technology also features dryer towers with repressurization cycle, which helps to reduce desiccant shock and lengthens the life of the absorbent material, saving downtime and service costs.
When you take all of this into account, as far as overall efficiency goes, the new technology surrounding desiccant dryers is by far the best choice.
Refrigeration has made the quality of all of our lives better. It preserves our food, keeps our beverages cold, and gave 1985 Chicago Bears star William “The Refrigerator” Perry a clever nickname! However, when it comes to removing moisture from your medical air, desiccant is the way to go. By:
Brian Benson NITC 6005 Medical Gas System Specialist |
