Is your air system delivering Clean, Dry Air to your powder coating equipment?
Almost every time I ask this question I hear "We have an Air Dryer right after our compressor, so we're good" The truth is.....NOT NECESSARILY!
First let's understand Moisture in Air Compressors, why it is there, how we get rid of it & why it is important that only use clean, dry air in our finishing system.
- Moisture accumulation in any air system is a common issue and is typically caused by humid air being compressed. When air is compressed it's temperature rises, and as it cools it creates water vapor and condensation. At this point the water vapor is easier to remove, but if you don't have a method in place to do that it will stay in the lines and can be costly on sensitive equipment and processes.
Let's look at a scenario that we see quite often: You have an aftercooler right after your compressor. This helps by cooling the air, thus creating moisture, which is then removed by the aftercooler prior to entering the storage tank. Your airlines then travel about 150 feet to your powder booth and gun, and it is summer time so the ambient air in your shop is hot & humid. The air in those lines will pick up heat as they travel to your booth, but then cools down as it enters the gun. As we learned above, compressed air creates moisture as it cools down, so now we have moisture right where we don't want it!
Types of Air Dryers
- Refrigerated Air Dryers: These types of dryers cool the compressed air, which then allows the water vapor to condense where it can easily be removed. These types of Air Dryers are effective for general applications where you don't need to provide ultra-dry air.
- Desiccant Air Dryers: These types of dryers use an absorbent material to capture the moisture to provide Ultra-Dry Air that is often necessary for sensitive processes such as finishing equipment, plasma cutting equipment, laser cutting equipment, etc.
Other ways of removing moisture and contaminants
- Moisture Traps and Separators: By installing moisture traps at the point-of-use you can remove any moisture that might have accumulated in the lines due to environmental reasons or if your air lines run through or by an area that causes them to rise in temperature.
A point-of-use Air Dryer is strongly suggested right where your air goes into your paint or powder gun. Also, if you have a Cartridge style booth with back-pulsing filters, clean dry air will help those filters last longer. If you are introducing moisture into the filters every time you back-pulse, the powder will get gummed up and not release from the filters correctly to keep them clean. You will also degrade the filter cloth media which could cause them to rip or tear and allow powder into your final filters.
If you have any questions about your air system, or if you are looking for a Point-of-Use air dryer let us know, we are happy to help!