Now thats interesting. Looks like the 1/4J is the one to use, but its going to trend toward slightly small droplets. BUT. They dont say what fluid pressures on those charts? It also looks to me like there is no difference made by changing the air pressure from 10 PSI o 40 PSI? That doesnt seem right to me. If its true, then why not use the lower air pressure?
That chart agrees very well with the one I posted earlier:
So, if we want droplets between 20 micron and 80 micron it works out that 20 micron droplets fall at roughly 25 seconds per foot. Neither chart has 80 micron size listed, and I havent had time to plot a graph, or do the math to interpolate, but Im guessing its going to be around 1.5 - 2 seconds per foot.
So, for my chamber, which is aprox 2 ft tall, I want a maximum hang time of 50 seconds and a minimum of 3 to 4 seconds.
I dont see any way to judge the hang time of the larger droplets visually, so we are stuck just looking at the ones that hang the longest.
Based on those calculations, my hang time is way too long, which means I have a lot of droplets that are way too small. Im guessing down in the 5 to 10 micron range. Some of them hang at least three minutes or more down in the bottom of the chamber.
I suspect your situation is similar?