Compressed Air technology for blow off an cooling involves the use of air flow amplifying products in the form of air nozzles, air movers and air knives used in blow off, venturis for conveying, as well as vortex tube (cooling) technology. Virtually all of these products involve small openings for the compressed air to exit or in the case of vortex tubes, air spinning back and forth in the tube.
With air amplification products you can end up with clogged nozzles or uneven flow in the case of air knives. Venturis will not work as well due to blockages. Water or any moisture inside a vortex tube will freeze and stop the unit form performing temporarily until the ice thaws and the unit starts up again.
So the cleaner and more dry the air supply like the better – at least to 10 micron filtration of water. If there is oil in the airline, oil removal down to at least 1 micron is preferable. You may think your air line is clean and dry because at the compressor you have all the equipment for removing moisture and dirt. The problem is even in the cleanest of compressed air systems, several things happen downstream to cause dirt and moisture issue:
1. rusting of the piping that carries the compressed air due to stagnant low spots where condensation can collect.
2. entrainment of moisture from the atmosphere into the system because of leaks or other equipment.
3. condensation when the temperature of the compressed air falls below the dew point
So while treatment of the air is very important upstream at the compressor, point of use filtration is still important.